JPH06313077A - Production of thermoplastic resin and thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition retaining both mechanical strength and solvent resistance and having high impact strength by kneading in a molten state a composition comprising an olefinic rubber, aromatic vinyl monomer and propylene-based polymer. CONSTITUTION:This resin composition can be obtained by polymerization of a composition comprising (A) an olefinic rubber (pref. a propylene-based copolymer), (B) an aromatic vinyl monomer (pref. styrene) and (C) a propylene-based polymer and pref. (D) a functional group-bearing vinyl monomer under kneading, in a molten state, in the presence of a radical initiator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition and a method for producing a thermoplastic resin. More specifically, it has excellent impact resistance, high mechanical strength, solvent resistance and heat resistance. TECHNICAL FIELD The present invention relates to an olefin rubber-containing thermoplastic resin composition having excellent properties and transparency and a method for producing a thermoplastic resin.

[0002]

2. Description of the Related Art Propylene-based polymers are low in cost by themselves, have an excellent balance of physical properties such as heat resistance, solvent resistance and moisture permeation resistance, and have a low specific gravity. It is widely used as a film, sheet, molded product, etc., but has the drawback of poor low-temperature properties and poor impact physical properties, and cannot be used as it is for applications that require high impact strength. It was

Therefore, attempts have been made to improve impact properties by blending a rubber component such as an ethylene-α-olefin copolymer with a propylene polymer. Further, a propylene polymer and a blend of an ethylene-α-olefin copolymer rubber are melt-kneaded while partially cross-linking with a radical initiator to synthesize a thermoplastic resin composition having improved impact physical properties. Attempts have been made to do so.

However, merely blending a rubber component with a propylene polymer has an effect of improving impact properties, but rigidity, solvent resistance, heat resistance and the like are deteriorated, and a sufficiently satisfactory result is obtained. Has not been done. Further, in the method of partially impacting the propylene-based polymer and the ethylene-α-olefin copolymer by using a radical initiator to improve the impact properties, the amount of the ethylene-α-olefin copolymer and the radical initiator was limited. Only under the condition, the improvement effect is shown to some extent, and the improvement effect is limited. That is, since the propylene-based polymer itself is a radical-disintegrating polymer, when a radical initiator is simply melt-kneaded, a decomposition reaction also occurs, the melt flow index increases, and molding processing becomes impossible, and the obtained composition The physical properties of are deteriorated. Further, in order to suppress the decomposition reaction, if the addition amount of the radical initiator is reduced, the effect of improving the physical properties decreases, and thus, as long as the conventional method is followed, a limited propylene-based polymer and ethylene-α-olefin copolymer The composition ratio with the polymer and its improving effect are limited, and the application range is limited.

Furthermore, if the amount of the ethylene-α-olefin copolymer rubber is increased, the rigidity is inevitably lowered, so that the amount added is also limited (JP-A-54-500).
No. 57).

[0006]

Therefore, a thermoplastic resin or a thermoplastic resin excellent in impact resistance, in which various properties such as rigidity of a propylene-based polymer such as rigidity, solvent resistance, and heat resistance are almost maintained, are prepared. If a plastic resin composition is obtained, its application can be expanded, which is very useful.

The problem to be solved by the present invention is to produce a thermoplastic resin composition having various properties such as mechanical strength such as rigidity, solvent resistance, heat resistance and the like and high impact strength, and a thermoplastic resin. Is to provide a method.

[0008]

The present inventors have focused on the problems to be solved by the invention as described above,
As a result of extensive studies, a thermoplastic resin containing a specific olefin rubber obtained by melt-kneading a molten olefin rubber, an aromatic vinyl monomer, and a propylene polymer in the presence of a radical initiator. The resin and the thermoplastic resin composition, due to the addition effect of the aromatic vinyl monomer and the radical initiator, without lowering the characteristics of the propylene-based polymer, until finding that it has a high impact strength, Here, the present invention has been completed.

[0009]

[Structure] That is, according to the present invention, an olefin rubber (A) and an aromatic vinyl monomer, preferably an aromatic vinyl monomer and a functional group-containing vinyl monomer (B) are added in the presence of a radical initiator. A thermoplastic resin composition containing a thermoplastic resin obtained by a melt-kneading polymerization reaction with a propylene polymer (C), and an olefin rubber (A) and an aromatic vinyl monomer, preferably aromatic Group vinyl monomer and functional group-containing vinyl monomer (B) and propylene polymer (C)
And a melt-kneading polymerization reaction in the presence of a radical initiator, to a method for producing a thermoplastic resin.

The present invention will be described in detail below. The olefin rubber used in preparing the olefin rubber-containing thermoplastic resin is preferably a propylene copolymer rubber, specifically, a propylene-butene copolymer rubber, a propylene-ethylene copolymer. Examples include EPM, which is a polymer, EPDM, which is a ternary copolymer obtained by copolymerizing a diene monomer (ethyldenfulbornene, etc.), etc., as a third component, and other olefinic rubbers, 1,2. Polybutadiene etc. can also be used.

Specific examples of the aromatic vinyl monomers to be reacted include only styrene, methylstyrene, vinyltoluene, vinylxylene, ethylvinylbenzene, isopropylstyrene, chlorostyrene, dichlorostyrene and bromostyrene. These may be used alone or in combination of two or more. Of these, styrene is preferably used. The amount of the aromatic vinyl monomer added is preferably 35% by weight or less with respect to the olefin rubber-containing thermoplastic composition. If it exceeds 35% by weight, the various performances of the propylene-based polymer or the olefin-based rubber are liable to be impaired, which is not preferable.

It is also possible to use a vinyl monomer having a functional group in combination with the aromatic vinyl monomer. Specific examples of the functional group-containing vinyl monomer include an epoxy group-containing vinyl monomer, a carboxyl group-containing vinyl monomer, a hydroxyl group-containing vinyl monomer, and an amino group-containing vinyl monomer.
By using these functional group-containing vinyl monomers in combination, the paintability, printability and adhesiveness of the product can be improved and improved.

The amount of the functional group-containing vinyl monomer added is 10 with respect to the olefin rubber-containing thermoplastic composition.
Weight% or less is preferable, more preferably 1 to 5% by weight.
Within the range, it is appropriate. If the amount of vinyl monomer added is larger than the above amount, the polymerization rate is lowered, and the amount of unreacted monomer is increased, which is not preferable, and
Along with that, there arises a problem that mechanical properties are deteriorated. When the functional group-containing vinyl monomer is used in combination with the aromatic vinyl monomer, the amount of the functional group-containing vinyl monomer added is at least the same amount or more, preferably 1 to 5 times the amount of the aromatic vinyl monomer. Is preferably used.

The aromatic vinyl monomer used in the present invention undergoes a reaction such as a grafting reaction on a propylene polymer or an olefin rubber or a partial crosslinking reaction between both resins by reacting under the present conditions. , The effect of improving the decrease in the rigidity of thermoplastic containing olefinic rubber,
The effect of preventing the lowering of the molecular weight of the propylene-based polymer, the effect of accelerating the reaction rate of the functional group vinyl monomer, etc. are recognized,
Further, it is possible to impart a paintability improving effect, a transparency improving effect and the like.

The propylene-based polymer refers to a propylene homopolymer and a copolymer mainly composed of propylene and other olefins or ethylenic vinyl monomers. Such a propylene-based polymer is
In all cases, it is preferable that propylene is contained in an amount of 75% by weight or more. Specifically, isotactic polypropylene, propylene-ethylene copolymer, propylene-ethylene-butene copolymer, propylene-butene copolymer, maleic anhydride-modified polypropylene and the like are particularly representative. Of course, these propylene-based polymers may be mixed and used. Further, other polymers may be used within the range that does not impair the effects of the present invention and that does not impair the properties of the propylene-based polymer, beyond the object of the present invention.

As the radical initiator, the characteristic feature of the present invention is that the melt-kneading polymerization reaction is carried out at the melt-kneading temperature of the propylene-based polymer, so that the decomposition temperature for obtaining a half-life of 1 minute is obtained. Is preferably a radical initiator in the range of 130 to 250 ° C. Specific examples of the radical initiator having such characteristics include tert-
Butyl peroctate, bis (tert-butyl peroxy) trimethylcyclohexane, cyclohexanone peroxide, benzoyl peroxide, dicumyl peroxide, tert-butyl perbenzoate, dimethyl di (tert-butyl peroxy) hexane or dimethyl di (tert) Radical initiators such as -butylperoxy) hexyne are particularly representative. The total amount of vinyl monomers used is 10
Generally, the range of 0.1 to 10 parts by weight is preferable, and the range of 1 to 5 parts by weight is more preferable.

In the melt-kneading polymerization reaction, it is necessary to use a stabilizer as another additive because the propylene-based polymer itself is a radical-disintegrating polymer unlike polyethylene. However, it is necessary to consider the type and amount of addition so as not to hinder the polymerization of various vinyl monomers as described above.

As the stabilizers, only representative ones are exemplified by pentaerythrityl-tetrakis (di-tert-butyl-hydroxyphenyl) propionate and ocdecyl (di-tert-butyl-hydroxyphenyl) propionate. , Hindered phenolic stabilizers such as thiobis (methyl-tert-butylphenol) or trimethyl-tris (di-tert-butylhydroxybenzyl) benzene;
Various phosphorus-based stabilizers such as tetrakis (di-t-butylphenyl) biphenylene phosphite or tris (di-t-butylphenyl) phosphite; various metal soaps such as zinc stearate or calcium stearate; or Various antacid adsorbents such as magnesium oxide or hydrotalcite.

The amount of the stabilizer used is usually 0.01 to 1 with respect to 100 parts by weight of the propylene polymer.
Parts by weight, preferably 0.05 to 0.5 parts by weight.
In addition, the stabilizer needs to be mixed with the propylene-based polymer in advance by using a Henschel mixer or the like.

The method for producing the olefin rubber-containing thermoplastic resin and the thermoplastic resin composition of the present invention will be described below. Olefin rubber, aromatic vinyl monomer, aromatic vinyl monomer and vinyl monomer containing functional group, olefin rubber, propylene polymer and aromatic vinyl monomer, or aromatic vinyl monomer Body and functional group-containing vinyl monomer in the presence of a radical initiator in the melt kneading polymerization reaction, various closed containers such as Banbury mixer, or various continuous kneaders such as extruders, commonly used resins It can be performed using a melt-kneader or the like. In particular, a continuous kneader such as an extruder is preferable, and further, a twin-screw extruder is used for supplying reactants, kneading,
It is more preferable because it is excellent in terms of control and control of reaction temperature or polymerization time.

The actual preparation is an aromatic vinyl monomer, or an aromatic vinyl monomer and a functional group-containing vinyl monomer, a powdery propylene polymer impregnated with a radical initiator, and an olefin rubber. The mixture is supplied to a twin-screw extruder, heated to 130 to 250 ° C. under pressure to perform a melt-kneading polymerization reaction, and then the strand discharged from the die is cooled and obtained as pellets using a pelletizer. . Alternatively, an aromatic vinyl monomer or an aromatic vinyl monomer and a functional group-containing vinyl monomer, a radical initiator, and an olefin-based rubber mixture are supplied to a twin-screw extruder, and the same operation as above is performed. The propylene polymer may be melt-kneaded with the obtained thermoplastic resin.

It is necessary to select the temperature of the melt-kneading at or above the temperature required for melting the polymer and at the temperature at which the polymer does not decompose. In particular, it is necessary to select appropriate reaction conditions from the relationship between the reaction initiation decomposition temperature of the radical initiator and the residence time in the reactor.

The vinyl monomers used in these reactions may be added to the molten olefin rubber and propylene polymer mixture using a liquid feeder to carry out the polymerization reaction. Regarding the radical initiator, it may be dissolved in vinyl monomers in advance and added, or it may be added together with the vinyl monomer to the olefin rubber / propylene polymer mixture using a liquid feeder. Alternatively, it may be added by being dissolved in vinyl monomers and impregnated with an olefin rubber or a propylene polymer in advance.

After the completion of this reaction, it is preferable to perform vacuum suction at a vacuum degree of about 2 mmHg through a suction vent port attached to the extruder. This makes it possible to remove a small amount of unreacted monomer.

When the thermoplastic resin is obtained by the melt-kneading reaction, the vinyl monomer does not always 100% graft-react to modify the olefin-based rubber or the propylene-based polymer. In addition to those obtained by reaction-bonding a vinyl-based rubber, a reaction-bonded vinyl monomer and a propylene-based polymer, and a reaction-bonded olefin-based rubber and a propylene-based polymer, a vinyl monomer alone Coal, olefin rubber, and propylene polymer are also by-produced. Therefore, the thermoplastic resin in the present invention also includes these non-graft polymers.

The resin and resin composition thus obtained can be used as various molded articles by blending pigments, fillers, antistatic agents, etc., and injection molding, extrusion molding,
It can be molded by a commonly used molding method such as blow molding.

The propylene-based polymer is, as described above,
Unlike ethylene-based polymer, because it is a radical-disintegrating polymer, if it is simply melt-kneaded with a radical initiator,
Due to the cleavage of the main chain, a decrease in molecular weight is likely to occur, but when this reaction is carried out by adding an aromatic vinyl monomer, the vinyl monomers can be efficiently treated without causing a decrease in molecular weight. An olefin rubber-containing thermoplastic resin that has been graft-reacted is obtained.

The olefinic rubber-containing thermoplastic resin and thermoplastic resin composition of the present invention thus obtained have high impact strength, and have rigidity, transparency, solvent resistance, heat resistance, etc. It maintains various physical properties and can be used for a wide range of purposes.

[0029]

EXAMPLES Next, the present invention will be described with reference to Examples and Comparative Examples.
This will be described more specifically. However, the present invention is not limited to these examples. In the following,
Parts and% are based on weight unless otherwise specified.

(Example 1) "High pole B200P"
(Powdered polypropylene manufactured by Mitsui Petrochemical Co., Ltd.) 10
In 0 part, 0.05 part of "Irganox 1010" (phenolic antioxidant manufactured by Ciba-Gaiki), 0.1 part of "phosphite 168" (phosphorus antioxidant manufactured by Ciba-Gaiki) and calcium stearate. 0.05 part of (stabilizer) was mixed in advance with a Henschel mixer or the like to prepare a stabilizer-blended polypropylene.

Next, the above-mentioned stabilizer-blended polypropylene 5
5 parts, "Tufmer P-" which is a propylene-based copolymer rubber
0180 "(Mitsui Petrochemical Co., Ltd.) 30 parts styrene 15
The mixture was thoroughly impregnated with 0.45 parts of "Perhexin 25B" (initiator manufactured by NOF CORPORATION) using a mixing stirrer such as a Henschel mixer, and the mixture was mixed with a plast mixer manufactured by Brabender, Germany. The sample was put into a jacket whose jacket temperature was set to 200 ° C. in advance, and a melt-kneading polymerization reaction was performed for 6 minutes at a rotation speed of 40 rpm.

The styrene reaction rate in the product is determined by measuring the infrared spectroscopic analysis of the reaction product, that is, the styrene content (content rate) is 700 cm.
^-1 (assigned to styrene) and 1380 cm ^-1 punished determined from calibration curve based on the ratio of the (attributable to polypropylene), 96%
Met. The reaction product is heated to 200 using a hydraulic press.
A sheet having a thickness of 1 mm was prepared under the condition of 150 ° C. and 150 ° C.

The 1 mm sheet thus obtained was subjected to impact strength, tensile strength, elongation, and
The 100% modulus and the transparency (HAZE) were evaluated. The results are collectively shown in Tables 1 and 2.

As a result, the sheet was not broken by the falling weight impact test. Further, as compared with Comparative Example 3, the other mechanical properties were improved in all cases. Also in terms of transparency, the haze is lower than that of polypropylene (Comparative Example 1) and rubber-containing polypropylene (Comparative Example 3), and it can be seen that it has high transparency.

(Example 2) 70 parts of the above polypropylene containing stabilizer, 30 parts of "Tufmer P-0180" (manufactured by Mitsui Petrochemical Co., Ltd.), 12 parts of styrene, 3 parts of glycidyl methacrylate and "Perhexin 25B" (NOF Corporation) (stock)
A mixture of 0.3 parts of the production initiator) was subjected to a melt-kneading polymerization reaction under the same conditions as in Example 1.

The physical properties were evaluated in the same manner as in Example 1. As a result, as in Example 1, the sheet did not break in the falling weight impact test. As compared with Comparative Example 3, the other mechanical properties were improved in all cases. Also in terms of transparency, the haze is lower than that of polypropylene (Comparative Example 1) and rubber-containing polypropylene (Comparative Example 3), and it can be seen that it has high transparency.

(Example 3) 15 parts of the above polypropylene containing stabilizer, 70 parts of "Tufmer P-0180" (manufactured by Mitsui Petrochemical Co., Ltd.) and 15 parts of styrene, and "Perhexin 25
A mixture of 0.45 parts of "B" (initiator manufactured by NOF CORPORATION) was subjected to melt-kneading polymerization reaction under the same conditions as in Example 1.

The physical properties were evaluated in the same manner as in Example 1. As a result, it can be seen that it has higher rigidity than Comparative Examples 2 and 4 and has a high insoluble fraction of 67.6%, which is excellent in solvent resistance.

(Example 4) "Toughmer P-0180"
(Mitsui Petrochemical Co., Ltd.) 70 parts styrene 30 parts, "Perhexin 25B" (Initiator manufactured by NOF Corporation) 0.
A mixture of 9 parts was mixed under the same conditions as in Example 1,
A melt-kneading polymerization reaction was performed. Obtained thermoplastic resin 50
50 parts of "HIPOL B200P" (powdered polypropylene manufactured by Mitsui Petrochemical Co., Ltd.) was melt-kneaded.

The physical properties were evaluated in the same manner as in Example 1 below. As in Example 3, it was found that it showed higher rigidity than Comparative Example 2 and was excellent in solvent resistance. (Example 5) 55 parts of stabilizer-blended polypropylene obtained in the same manner as in Example 1, "EP-07" which is a propylene-ethylene copolymer rubber (manufactured by Japan Synthetic Rubber Co., Ltd.)
30 parts with 15 parts styrene, "Perhexin 25B"
A mixture of 0.45 parts of (Initiator manufactured by NOF CORPORATION) was subjected to melt-kneading polymerization reaction under the same conditions as in Example 1.

The reaction rate of styrene in the product thus obtained was 98% as determined by measuring the infrared spectroscopic analysis of the reaction product in the same manner as in Example 1.
The reaction product was made into a 1 mm thick sheet using a hydraulic press, and impact strength, tensile strength, elongation, 100% modulus and transparency (HAZE) were evaluated in the same manner as in Example 1. The results are collectively shown in Table 3 and Table 4.

As a result, the sheet was not broken by the falling weight impact test. Further, in comparison with Comparative Example 7, the other mechanical properties were improved in all cases. Also in terms of transparency, the haze is lower than that of polypropylene (Comparative Example 1) and rubber-containing polypropylene (Comparative Example 7), and it can be seen that it has high transparency.

(Example 6) 15 parts of the above polypropylene containing stabilizer, "EP-07" (manufactured by Japan Synthetic Rubber Co., Ltd.)
70 parts with 15 parts styrene, "Perhexin 25B"
A mixture of 0.45 parts of (Initiator manufactured by NOF CORPORATION) was subjected to melt-kneading polymerization reaction under the same conditions as in Example 1. The physical properties were evaluated in the same manner as in Example 1 below. It can be seen that it has higher rigidity than Comparative Example 8 and is excellent in solvent resistance.

(Example 7) 23 parts of polypropylene containing stabilizer, "EP-07" (manufactured by Nippon Synthetic Rubber Co., Ltd.)
70 parts of styrene and 7 parts of "Perhexin 25B"
A mixture prepared by mixing 0.21 parts of (Initiator manufactured by NOF CORPORATION) was subjected to a melt-kneading polymerization reaction under the same conditions as in Example 1.

The physical properties were evaluated in the same manner as in Example 1. Similar to Example 6, it was found that the rigidity was higher than that of Comparative Example 8 and the solvent resistance was also excellent (Comparative Example 1). Under similar conditions, melt kneading is performed,
The physical properties were evaluated in the same manner as in Example 1 below.

(Comparative Example 2) "Toughmer P-0180"
(Mitsui Petrochemical Co., Ltd.) was melt-kneaded under the same conditions as in Example 1 with the composition shown in Table 2.

The physical properties were evaluated in the same manner as in Example 1. When the insoluble fraction was calculated under the conditions described below, it was 3.8%, indicating that the solvent resistance was poor. (Comparative Example 3) A mixture of 70 parts of a stabilizer-blended polypropylene and 30 parts of "Toughmer P-0180" (manufactured by Mitsui Petrochemical Co., Ltd.) was melt-kneaded under the same conditions as in Example 1.

It can be seen that the obtained resin is peeled off and the resin is not well dispersed. The physical properties were evaluated in the same manner as in Example 1 below. (Comparative Example 4) A mixture of 30 parts of stabilizer-blended polypropylene and 70 parts of "Tufmer P-0180" (manufactured by Mitsui Petrochemical Co., Ltd.) was melt-kneaded under the same conditions as in Example 1.

As in Comparative Example 3, the obtained resin was delaminated, and it was found that the dispersed state was also bad. The physical properties were evaluated in the same manner as in Example 1 below. (Comparative Example 5) 70 parts of polypropylene containing stabilizer, 30 parts of "Toughmer P-0180" (manufactured by Mitsui Petrochemical Co., Ltd.), "Perhexin 25B" (initiator manufactured by NOF Corporation)
When 0.45 parts of the mixture was melt-kneaded under the same conditions as in Example 1, the melt viscosity was low,
The melt flow became too large and the decomposition reaction of polypropylene occurred simultaneously, so that an appropriate sample could not be obtained.

(Comparative Example 6) A propylene-ethylene copolymer rubber "EP-07" (manufactured by Nippon Synthetic Rubber Co., Ltd.) was melt-kneaded under the same conditions as in Example 1. The physical properties were evaluated in the same manner as in Example 1 below. When the insoluble fraction was calculated under the conditions described below, it was 34.9%, indicating that the solvent resistance was poor.

(Comparative Example 7) Stabilizer-blended polypropylene 7
No. 0, "EP-07" (manufactured by Japan Synthetic Rubber Co., Ltd.) 30
The mixed parts were melt-kneaded under the same conditions as in Example 1.

It can be seen that the obtained resin is peeled off and the resin is not well dispersed. The physical properties were evaluated in the same manner as in Example 1 below. (Comparative Example 8) Stabilizer-blended polypropylene 30 parts, "EP
A mixture of 70 parts of "-07" (manufactured by Japan Synthetic Rubber Co., Ltd.) was melt-kneaded under the same conditions as in Example 1.

The obtained resin was clouded and exfoliated in the same manner as in Comparative Example 7, showing that the dispersed state was also poor. The physical properties were evaluated in the same manner as in Example 1 below. Table 1
The tests of to 4 were performed by the following method. <Test conditions> (1) Impact test: Using a DuPont-type falling weight tester (manufactured by Kitahama Seisakusho Co., Ltd.), at a temperature of 23 ° C., using a 1 / 2-inch hammer, each weight of 500 g was weighed. The minimum height at which the test piece was broken by dropping it on a 1 mm thick press sheet was determined as the falling weight impact strength. Also, when the test piece does not break due to the drop of the weight from the height of 50 cm. It was set to B.

(2) Tensile test: Each 1 mm-thick press sheet was punched out with a No. 3 dumbbell, and an autograph IM-100 (manufactured by Shimadzu Corp.) was used to pull at a pulling speed of 5
Elongation at break (%), tensile strength at break (kg / cm ² ), 100% modulus (kg /
cm ² ) was measured.

(3) Transparency (HAZE): The transparency was evaluated by haze (%), and each 1 mm thick press sheet was measured by a haze meter (manufactured by Toyo Seiki Co., Ltd.).

(4) Appearance: The state when each press sheet was torn was visually evaluated. When the state at that time was delaminated, the layer was delaminated, and when the dispersion was good, it was denoted as "good".

(5) Solvent resistance: The solvent resistance of each product was evaluated by using tetrahydrofuran as an extraction solvent.
Soxhlet extraction method for 4 hours,
The insoluble fraction was calculated and evaluated by dividing the residue by the weight before extraction.

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

[0061]

[Table 4]

[0062]

The olefin rubber-containing thermoplastic resin and the thermoplastic resin composition obtained by the present invention have mechanical properties such as rigidity of a propylene polymer, solvent resistance, moisture permeability resistance, heat resistance, etc. It has excellent impact resistance by a simple method without losing various characteristics of 1., and is particularly useful because it can be applied particularly to automobile parts and the like.

Claims (8)

[Claims] 1. A thermoplastic resin obtained by melt-kneading a composition in a molten state containing an olefin rubber (A) and an aromatic vinyl monomer (B) in the presence of a radical initiator. A thermoplastic resin composition containing a propylene polymer (C). 2. The thermoplastic resin composition according to claim 1, wherein a vinyl monomer having a functional group is further added to the aromatic vinyl monomer. 3. The thermoplastic resin composition according to claim 1 or 2, wherein the olefin rubber (A) is a propylene copolymer. 4. The thermoplastic resin composition according to any one of claims 1 to 3, wherein the aromatic vinyl monomer (B) is styrene. 5. A composition in a molten state containing an olefin rubber (A), an aromatic vinyl monomer (B) and a propylene polymer (C) is melt-kneaded and polymerized in the presence of a radical initiator. A method for producing a thermoplastic resin, which comprises reacting. 6. The method for producing a thermoplastic resin according to claim 5, wherein a vinyl monomer having a functional group is further added to the aromatic vinyl monomer. 7. The method for producing a thermoplastic resin according to claim 5, wherein the olefin rubber (A) is a propylene copolymer. 8. The method for producing a thermoplastic resin according to claim 5, wherein the aromatic vinyl monomer (B) is styrene.