JPH02191617A - Production of impact-resistant aromatic-based resin - Google Patents

Abstract

PURPOSE:To obtain the title resin comprising dispersed rubber particles having a specific median particle diameter, specific intrinsic viscosity, excellent impact resistance, appearance characteristics and mechanical characteristics by polymerizing an aromatic vinyl compound in the presence of a specific aromatic vinyl- conjugated diene-based copolymer. CONSTITUTION:An aromatic vinyl compound (preferably styrene) is polymerized in the presence of an aromatic vinyl-conjugated diene-based copolymer which is, for example, obtained by subjecting an aromatic vinyl compound and a conjugated diene to solution polymerization in the presence of an organolithium compound as a catalyst, has 550-2,000 centipoise viscosity in 5wt.% styrene solution at 25 deg.C, 13-30wt.% vinyl bond content of conjugated diene part and <=14wt.% bond content of aromatic vinyl compound component to give the aimed resin comprising dispersed rubber particles having 1-2.5mum median particle diameters and >=0.7dl/g intrinsic viscosity of resin component.

Description

Detailed Description of the Invention: a9 Industrial Field of Application The present invention relates to a method for producing impact-resistant aromatic vinyl resins, and more particularly, to a method for producing impact-resistant aromatic vinyl resins, and more particularly, to a method for producing impact-resistant aromatic vinyl resins, and more specifically, to produce impact-resistant aromatic vinyl resins with excellent balance between impact resistance, appearance characteristics, and mechanical properties. The present invention relates to a method for producing an impact-resistant aromatic vinyl resin.

b. Conventional technology In general, aromatic vinyl resins such as styrene resins are
Although it has many excellent properties such as good fluidity during processing and molding, and good transparency and gloss of molded products, it has a major drawback of poor impact resistance.

Known methods to compensate for these drawbacks include: (1) dispersing a rubbery polymer in a resin using a mechanical method, and (2) grafting an aromatic vinyl compound (for example, styrene) onto a rubbery polymer. .

However, in the above method (1) in which a rubbery polymer is dispersed in a resin by a mechanical method, only a brittle mixture is obtained if there is no affinity between the rubbery polymer and the resin. In addition, when the affinity between the two is good, impact resistance is improved, but such resins do not sufficiently improve mechanical properties other than impact resistance, and the surface gloss of molded products is not excellent. Furthermore, since the rubber-like polymer is not crosslinked, the molded product has a large degree of orientation.

On the other hand, in the method (2) of graft polymerizing an aromatic vinyl compound onto a rubbery polymer, the impact resistance of the resulting resin is improved, but properties such as mechanical properties, orientation, and surface gloss are still sufficiently satisfactory. It's not possible.

As a method to improve this drawback, it has been proposed to use a butadiene polymer containing a large number of vinyl bonds as a rubber-like polymer and to graft-polymerize styrene thereto (Japanese Patent Publication No. 45-40546, Japanese Patent Publication No. Showa 59-18
No. 4216).

C9 Problems to be Solved by the Invention However, the resin obtained by the above method (1) in which a butadiene polymer containing a large number of vinyl bonds is used as the rubbery polymer and styrene is graft-polymerized thereon is as follows:
Although the orientation and surface gloss are improved, they are still not sufficient, and they have the disadvantages of low mechanical properties, especially low tensile strength, and poor impact resistance at low temperatures.

Further, when a polymer having a low solution viscosity is used, a problem arises in that the impact resistance of the resulting impact resistant aromatic vinyl resin is reduced.

In view of the problems of the conventional methods, the present inventors conducted extensive studies with the aim of obtaining an impact-resistant aromatic vinyl resin with an excellent balance of resin impact resistance, appearance characteristics, and mechanical properties. As a result, an aromatic vinyl-conjugated diene copolymer having a specific solution viscosity range and a specific structure was used as a rubber-like polymer, and an aromatic vinyl compound was graft-polymerized onto this to create rubber particles dispersed in the resin. The present invention was achieved by discovering that the above technical problem can be solved by adjusting the diameter within a specific range.

Means for Solving the d0 Problem That is, the present invention provides a method for polymerizing an aromatic vinyl compound in the presence of an aromatic vinyl-conjugated diene copolymer. ■ The viscosity of a 5% styrene solution measured at 25°C is 5
50 to 2000 centivoise, ■ The vinyl bond content of the conjugated diene part is 13 to 30%, ■ The bond content of the aromatic vinyl compound component is 14% by weight.
Hereinafter, the median particle size of the rubber particles dispersed in the obtained resin is in the range of 1 to 2.5 μm, and the intrinsic viscosity (in toluene at 25°C) of the resin component excluding the rubber component is 0.7 d.
1. The present invention provides a method for producing an impact-resistant aromatic vinyl resin, which is characterized by adjusting the .

In the present invention, a specific aromatic vinyl-conjugated diene copolymer is first produced, and an aromatic vinyl compound is graft-polymerized thereon in the presence of an ordinary radical polymerization initiator, thereby improving impact resistance and appearance properties. and aromatic vinyl resins with excellent balance of mechanical properties.

The aromatic vinyl-conjugated diene copolymer used in the present invention is usually obtained by solution polymerizing an aromatic vinyl compound and a conjugated diene compound using an organic lithium compound as a catalyst.

Examples of the aromatic vinyl compounds include styrene, p-methylstyrene, vinyltoluene, α-methylstyrene,
Examples include 3,5-dimethylstyrene, and styrene is preferred.

In addition, conjugated diene compounds include 1,3-butadiene, 1,3-pentadiene, isoprene, chlorobrene,
1.3-hexadiene, 2.4-hexadiene, 2,3
-dimethyl-1,3-butadiene, 2-ethyl-1,3
-butadiene, 1°3-heptadiene, etc., as well as various branched conjugated diene compounds having 4 to 7 carbon atoms,
Preferably 1,3-butadiene, isoprene, 1,3-
Pentadiene, particularly preferably 1,3-butadiene.

In addition, examples of organic lithium compounds that are catalysts for solution polymerization of aromatic vinyl compounds and conjugated diene compounds include n-propyllithium, isopropyllithium, n-butyllithium, 5ee-butyllithium, t
ert-butyllithium, n-pentyllithium, lithium toluene, benzyllithium, 1,4-dilithio-
〇-Butane, 1,2-dilithio-1,2-diphenylethane, trimethylene lithium, 2-diphenylethane,
Examples include trimethylene dilithium, oligoisoprenyl dilithium, etc. - For boat fishing, n-butyl lithium, 5
ee-butyllithium.

Furthermore, the solvent used in the solution polymerization is preferably a hydrocarbon solvent, such as pentane, hexane, heptane, cyclohexane, methylcyclopentane, benzene, toluene, xylene, etc. It can be used alone or in combination of two or more.

The aromatic vinyl-conjugated diene copolymer used in the present invention may be a copolymer having a block portion. However, in order to fully obtain the effects of the present invention, it is desirable to use a copolymer that is as randomized as possible, that is, has almost no block portions. Therefore, during the solution polymerization, the amount of vinyl bond in the resulting aromatic vinyl-conjugated diene copolymer is adjusted, and block polymerization of the aromatic vinyl compound is prevented to obtain a random copolymer. For this purpose, Lewis bases represented by ether compounds such as dimethyl ether, diethyl ether, and tetrahydrofuran; thioether compounds such as dimethyl sulfide and diethyl sulfide; and amine compounds such as dimethylethylamine, tri-n-propylamine, and triethylamine are added to the polymerization system. can do.

In addition, as another method for obtaining a random copolymer by inhibiting block polymerization of the aromatic vinyl compound,
There is a method in which copolymerization is carried out while adding a mixed solution of an aromatic vinyl compound and a conjugated diene compound to a solution containing an organolithium compound at a rate slower than the reaction rate of both monomers, the aromatic vinyl compound and the conjugated diene compound.

Moreover, the reaction operation temperature for the solution polymerization is a normal polymerization temperature, for example, 50 to 150°C, preferably 70 to 120°C.

Furthermore, the aromatic vinyl-conjugated diene copolymer used in the present invention is a rubber-like polymer obtained by polymerizing an aromatic vinyl compound and a conjugated diene compound as described above, and furthermore, the following It is necessary to satisfy the requirements of ~■.

■The viscosity of the 5fffffi% styrene solution at 25°C is 550 to 2000 centiboise, preferably 600 to 1
It is 500 centipoise.

The viscosity of a 5% by weight styrene solution of the aromatic vinyl-conjugated diene copolymer used in the present invention measured at 25°C is 5%.
If it is less than 50 centivoids, it will be difficult to simultaneously achieve the particle size and intrinsic viscosity of the rubber particles dispersed in the aromatic vinyl resin as specified in the present invention, resulting in poor impact resistance. On the other hand, if the viscosity of a 5% styrene solution measured at 25°C exceeds 2000 centipoise, the solubility in styrene will be significantly reduced and it will take a long time to dissolve in the production of impact-resistant aromatic vinyl resin. This is undesirable because productivity decreases, and the particle diameters of the dispersed rubber particles also become irregular, resulting in a decrease in gloss.

The viscosity of the 5% by weight styrene solution described in -1- can be adjusted by the amount of the organolithium compound used in the solution polymerization of the aromatic vinyl-conjugated diene copolymer and the polymerization temperature. For example, when n-butyllithium is used as the organic lithium compound, the amount used is approximately 0.02 to 0.0. O5ppm, polymerization temperature about 70-120
By solution polymerizing an aromatic vinyl-conjugated diene copolymer at a temperature of 0.degree.

In addition, the vinyl bond content of the aromatic vinyl-conjugated diene random copolymer is 13 to 30%, preferably 14 to 2%.
5%, more preferably 15-20%.

If the amount of vinyl bond in the aromatic vinyl-conjugated diene copolymer used in the present invention is less than 13%, the resulting resin will have poor impact resistance and high orientation; If the amount exceeds 30%, the resulting resin will have good orientation, but low-temperature impact resistance will decrease, which is not preferable.

"The amount of bipedal vinyl bond can be easily adjusted by adding the Lewis base to the solution polymerization system of the aromatic vinyl-conjugated diene copolymer and selecting the amount added. be. For example, when tetrahydrofuran is used as the Lewis base, by rubbing the cooled amount of about 30 to 1,500 ppil against the solvent, the amount of vinyl bond in the resulting aromatic vinyl-conjugated diene copolymer can be adjusted to the above range. Can be adjusted.

Furthermore, ■ the amount of bond a of the aromatic vinyl compound component in the aromatic vinyl-conjugated diene copolymer is 14% by weight.
The content is preferably 1 to 12% by weight, more preferably 2 to 10% by weight, particularly preferably 3 to 8% by weight.

When the bond content of the aromatic vinyl compound component in the aromatic vinyl-conjugated diene copolymer used in the present invention exceeds 14% by weight, impact resistance at room temperature and low temperature decreases.

In the present invention, while using the specific aromatic vinyl-conjugated diene copolymer, the average particle diameter of the rubber particles dispersed in the resulting resin is 1 to 2.5 in median diameter.
μm1 preferably needs to be 1.2 to 2.3 μm. If the median diameter is less than 1 μm, impact resistance will be poor;
If it exceeds μm, only a product with poor gloss can be obtained.

In addition, the intrinsic viscosity of the resin is determined by dissolving the resin in toluene, separating it into a rubber component and a resin component using a centrifuge, and measuring the obtained resin component using an Ubbelohde viscometer in a toluene solution at 25°C. . The intrinsic viscosity of this resin component is 0.7dj! /g or more, preferably 0.7 to 1°4df! /g. 0.7df! /
If it is less than g, the impact resistance will be poor and undesirable.

As mentioned above, within the high intrinsic viscosity range and with a particle size of 1 to 1
In order to adjust the molecular weight to a specific range of 2.5 μm, it is difficult to simply adjust the rotation speed of stirring during graft polymerization, which is usually done. , preferably 250 p
pm or less and the aromatic vinyl-conjugated diene copolymer having the above-mentioned specific solution viscosity is used.

Next, the present invention uses the specific aromatic vinyl-conjugated diene copolymer and graft-polymerizes an aromatic vinyl compound thereto.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, vinylnaphthalene, vinylethylbenzene, vinylxylene, etc., but preferably styrene,
α-methylstyrene and p-methylstyrene, more preferably styrene.

Further, the method of radical copolymerizing the aromatic vinyl compound to the specific aromatic vinyl-conjugated diene copolymer is not particularly limited, but for example, the method of radical copolymerizing the aromatic vinyl compound to the specific aromatic vinyl-conjugated diene copolymer This is carried out by bulk polymerization of a solution of an aromatic vinyl compound dissolved therein or by radical polymerization by a combination of bulk polymerization and suspension polymerization.

In the graft polymerization of the aromatic vinyl-conjugated diene copolymer and the aromatic vinyl compound, the mixing ratio of the aromatic vinyl-conjugated diene copolymer and the aromatic vinyl compound is from 3/97 to 15/1 in weight percent. 85, preferably 4/96~
It is 10/90.

If the amount of the aromatic vinyl-conjugated diene copolymer used is less than 3% by weight, the impact resistance of the resulting resin will decrease and it will be difficult to achieve the object of the present invention, whereas if it exceeds 15% by weight, graft polymerization will occur. Since the viscosity of the solution becomes extremely high, it becomes difficult to actually carry out graft polymerization.

When graft polymerization of an aromatic vinyl-conjugated diene polymer and an aromatic vinyl compound is carried out by bulk polymerization, the aromatic vinyl-conjugated diene copolymer is dissolved in the aromatic vinyl compound, and then, if necessary, Add a molecular weight regulator as required and polymerize.

Examples of molecular weight regulators used include α-methylstyrene dimer, n-decylmercaptan, tert-dodecylmercaptan, 1-phenylbutene-2-fluorene, dipentene, mercaptans such as chloroform, terpenes, and halogen compounds. .

Furthermore, a lubricant can be added to improve the moldability of the resulting resin. For example, ester lubricants such as butyl stearate and butyl phthalate, mineral oil, paraffin wax, and other lubricants used in conventional resin processing can be used.

After dissolving these in the above polymer solution, benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide, dicumyl peroxide, diisopropyl peroxydicarbonate, tert-butyl peroxy acetate were added as a polymerization initiator. , di-tert-butylshiba-oxyisophthalate or azobisisobutyronitrile, etc., and the reaction temperature was increased to 6°C under an inert gas atmosphere.
The polymerization reaction is completed while stirring at 0 to 200°C.

Furthermore, during bulk polymerization, it is also possible to initiate polymerization using heat or light without using a polymerization initiator.

During the bulk polymerization reaction, it is usually preferable to stir effectively until the polymerization rate of the aromatic vinyl compound reaches about 30%; It is preferable to ease the agitation after the temperature has been exceeded.

Further, at this time, a hydrocarbon solvent such as toluene, ethylbenzene, xylene, etc. may be added for the purpose of lowering the viscosity of the polymerization system.

After the polymerization is completed, the monomer and solvent are recovered from the polymerized product by removing the monomer and the solvent using a vented Ruder or steam stripping.

In addition, when graft polymerization of an aromatic vinyl-conjugated diene copolymer and an aromatic vinyl compound is carried out by a combination of bulk polymerization and suspension polymerization, first about 10 to 45 molecules of the monomer (aromatic vinyl compound) are Bulk polymerization is carried out until % of the polymer is converted into a polymer, and this solution is dispersed in an aqueous solution containing a suspension stabilizer such as polyvinyl alcohol, polymethacrylate, or tribasic calcium phosphate, while maintaining a suspended state. Polymerization is completed at a reaction temperature of 60 to 150°C. After the polymerization is completed, the polymerized product is thoroughly washed with water to remove the suspension stabilizer, and then dried to recover the aromatic vinyl resin.

In addition, when performing radical polymerization by the bulk polymerization or bulk-suspension polymerization, it is preferable that 50% by weight or more of the monomer used is the aromatic vinyl compound,
Less than 0% by weight of the monomer may be replaced with an aliphatic vinyl compound other than the above compound, such as acrylonitrile, methacrylonitrile, acrylic acid, methyl acrylate, or methyl methacrylate.

In addition, the resins obtained by both types of methods may contain known antioxidants, such as 2,6-tert-butyl-4-methylphenol, 2-(1-methylcyclohexyl)-4
, 6-dimethylphenol, 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), 4
．． 4'-thiobis=(5-tert-butyl-3-methylphenol), dilaurylthiodipropionate,
Tris(di-nonylphenyl) phosphite, wax; known UV absorbers such as p-tert-butylphenyl salicyle-1., 2,2'-dihydroxy-4-
Methoxybenzophenone, 2-(2'-hydroxy-4
'-n-octoxyphenyl)benzothiliazole; known lubricants such as paraffin wax, stearic acid,
Hydrogenated oils, stearamide, methylene bisstearamide, n-butyl stearate, ketone wax, octyl alcohol, lauryl alcohol, hydroxystearic acid triglyceride; known flame retardants such as antimony oxide, aluminum hydroxide, zinc borate, tricresyl phosphate, tris(dichloropropyl) phosphate, chlorinated paraffin, tetrabromobutane, hexabromobenzene, tetrabromobisphenol A; known antistatic methods, e.g. stearamidopropyldimethyl-β
- hydroxyethylammonium nitrate; known colorants such as titanium oxide, carbon black, other inorganic or organic pigments; known fillers such as calcium carbonate, clay, silica, glass fibers, glass spheres, carbon fibers, etc. required; It can be added depending on the situation.

e. Examples Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

In the examples, parts and percentages are expressed on a weight basis unless otherwise specified.

Moreover, various measurements in the examples were carried out according to the methods shown below.

The microstructure of the aromatic vinyl-conjugated diene copolymer was determined by infrared spectroscopy (Morello method), and the amount of bonded aromatic vinyl compound was determined by infrared spectroscopy at a wave number of 699c+n'''1.
Measure the intensity of the absorption peak due to the phenyl group in
The amount was determined from a previously determined calibration curve, and the viscosity of the 5% by weight styrene solution was measured at 25° C. using a Cannon-Fenske viscometer.

The molecular weight distribution of the aromatic vinyl-conjugated diene copolymer was measured using HLC-802A type GPC manufactured by Toyo Soda Kogyo ■ and a differential refractometer as a detector under the following conditions.

Column: Toyo Soda Kogyo Nakako Co., Ltd. Color 11, GMH-3, GMH-6 Mobile phase: Tetrahydrofuran Measurement temperature: 40°C The physical properties of the impact-resistant polystyrene resin were measured according to the following method.

Izotsu impact strength (1 part 4 inches, with notch): 8
The resulting resin was molded using an oz injection molding machine at a cylinder temperature of 200°C, and the molded product was rated according to ASTM D.
-256.

Tensile strength: Using an 8oz injection molding machine, cylinder temperature 2
The resin obtained at 00°C is molded, and the molded product is
Measured according to ASTM D-638.

Gloss: Using an 8oz injection molding machine, cylinder temperature 20
The resin obtained at 0°C is molded, and the molded product is A.
45'' reflective gloss was measured according to STM D-523.

Orientation: Using a 3.5oz injection molding machine, resin was introduced from the gate into an 80x64x2.4+++a+ mold at a cylinder temperature of 200°C, and a strip-shaped sample piece was placed so that its longitudinal direction was parallel to the flow direction of the resin. One in the vertical direction and one in the vertical direction were prepared, and the notched Izo impact strength of each sample was measured.

Moreover, the degree of non-orientation (%) was calculated using the following formula.

Median particle size of dispersed rubber particles: 1 to 2 resin pellets are placed in about 50 ml of dimethylformamide and left for about 3 hours. Next, this dimethylformamide solution was added to an electrolyte solution (ISOTON ■■), and the particle concentration was measured using a Coulter counter to obtain an appropriate particle concentration, and the 50% median particle size was calculated from the obtained particle size distribution.

Example 1 Using a polymerization reactor with an internal volume of 152 mm and equipped with a stirrer, 1,3-butadiene 1425 g/llr, styrene 75 g/Hr, and cyclohexane 10° 500 g/L were added from the bottom of the polymerization reactor.
firSn-butyllithium 0. 5/llr, tetrahydrofuran 0. The mixture was continuously supplied using a metering pump at a flow rate of 5 g/Jlr, and the inside of the polymerization reactor was maintained at 95° C. from beginning to end for polymerization. 0.0% per 100 parts of polymer is added to the polymerization solution continuously withdrawn from the top of the polymerization reactor.
5 parts of 2.6-sheet tert-butyl-p-cresol were added. The resulting polymer solution was desolvented by steam stripping and dried with a hot roll at 110°C to obtain a styrene-butadiene copolymer.

The Mooney viscosity (ML, 100°C) of the obtained styrene-butadiene copolymer was 127.5% by weight, 1+4% by weight. The viscosity of the styrene solution was 820 centiboise, the amount of vinyl bond was 15%, and the amount of bound styrene was 4°8%. , the molecular weight distribution (Mw/Mn) was 1.7.

Next, a mixture of 6 parts of the styrene-butadiene copolymer obtained above and 94 parts of styrene was stirred at room temperature for about 8 hours to uniformly dissolve the mixture. This solution was transferred to a polymerization reactor with an internal volume of 10° C. equipped with a stirrer, and 150 ppm of tert-dodecyl mercaptan and 0.0 ppm of benzoyl peroxide were added thereto.
05 parts, rotation speed 30 Orpm, 118°C
Polymerization was carried out until the polymerization rate of styrene reached approximately 30%.

Next, 0.05 part of dicumyl peroxide was added per 100 parts of the polymerization solution, and 150 parts of water containing 3 parts of tribasic calcium phosphate as a suspension stabilizer and 0.005 parts of sodium dodecylbenzenesulfonate as a surfactant was added. was added and suspended under stirring. The suspension mixture was heated to 120°C for 2 hours, 140°C for 2 hours, and then for 16 hours with stirring.
Polymerization was carried out by heating at 0° C. for 2 hours.

The resulting bead-shaped resin was distributed door to door, washed with water, dried, and made into pellets using an extruder.

The thus obtained styrenic resin was injection molded to prepare test pieces for measuring physical properties, and the physical properties were evaluated. The measurement results are shown in Table-1.

Example 2 In Example 1, the amount of tetrahydrofuran supplied was increased to 4.
The same procedure as in Example 1 was carried out except that the rate was changed to 2 g/Hr.

The results are shown in Table-1.

Example 3 In Example 1, the amount of n-butyllithium supplied was reduced to 0.
The same procedure as in Example 1 was carried out except that the rate was changed to 6 g/Hr.

The results are shown in Table-1.

Example 4 In Example-1, the amount of n-butyllithium supplied was set to 0.
．． The same procedure as in Example 1 was carried out except that the polymerization rate was changed to 4 g/Hr and the polymerization temperature was changed to 90°C. The results are shown in Table-1.

Comparative Example 1 The graft polymerization of the prepared styrene-butadiene copolymer was carried out in the same manner as in Example 1, except that the amount of t-dodecylmercaptan was changed to 700 ppm. The results are shown in Table-1.

Comparative Example 2 In Example 1, the amount of n-butyllithium supplied was changed to 0.
The same procedure as in Example 1 was carried out except that the supply of tetrahydrofuran to 8 g/)Ir was stopped and the amount of t-dodecylmercaptan during graft polymerization was changed to 700 ppll. The results are shown in Table-1.

Comparative Example 3 In Comparative Example 2, the amount of t-dodecyl mercaptan was reduced to 1
The same procedure as Comparative Example 2 was carried out except that the concentration was changed to 50 ppm. The results are shown in Table-1.

Comparative Example 4 In Example 1, the amount of 1,3-butadiene supplied was increased to 12
The same procedure as in Example 1 was carried out except that the styrene supply amount was changed to 75 g/Hr and 225 g/Hr.

The results are shown in Table-1.

Comparative Example 5 In Example 1, the amount of tetrahydrofuran supplied was changed to 21
The same procedure as in Example 1 was carried out except that the concentration was changed to g/Ilr.

The results are shown in Table-1.

Comparative Example 6 In Example 1, the amount of 1,3-butadiene supplied was increased to 14
67 g/IIr, styrene supply amount 33r/! 1"
The same procedure as in Example 1 was carried out except that .

The results are shown in Table-1.

Example 5 Polymerization of a styrene-butadiene copolymer was performed by changing the polymerization method to a batch method. That is, using a polymerization reactor with an internal volume of 10 ゜ and equipped with a stirrer, 4900 g of cyclohexane and 2.0 g of tetrahydrofuran were added. Or.

Charge 0.22g of n-butyllithium, and add 1.3g of n-butyllithium.
- A monomer mixture of 660 g of butadiene and 40 tons of styrene was continuously added to the reaction system using a metering pump so that the addition was completed in 1 hour, and polymerization was carried out at 85°C.

The results are shown in Table-1.

Margin below f1 Effects of the Invention According to the present invention, it is possible to obtain an impact-resistant aromatic vinyl compound resin with an excellent balance of impact resistance, appearance characteristics, and mechanical properties, and its industrial significance is extremely large. .

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (2)

[Claims] (1) In the method of polymerizing an aromatic vinyl compound in the presence of an aromatic vinyl-conjugated diene copolymer, the aromatic vinyl-conjugated diene copolymer contains [1] 5% by weight measured at 25°C. The viscosity of the styrene solution is 550 to 2000 centipoise, [2] The amount of vinyl bond in the conjugated diene part is 13 to 30%.
, [3] The bond content of the aromatic vinyl compound component is 14% by weight or less, and the median particle diameter of the rubber particles dispersed in the resulting resin is 1 to 2.5 μm, and the resin component excluding the rubber component A method for producing an impact-resistant aromatic vinyl resin, which comprises adjusting the intrinsic viscosity (in toluene at 25° C.) of 0.7 dl/g or more. (2) The method for producing an impact-resistant aromatic vinyl resin according to claim 1, characterized in that during the polymerization, the amount of the molecular weight regulator is 300 ppm or less based on the aromatic vinyl compound.