JP3248558B2 - Polypropylene resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition having excellent balance of fluidity, rigidity, impact resistance and appearance of a molded product.

[0002]

2. Description of the Related Art Polypropylene has been widely used in various molded articles and sheets because of its excellent moldability, toughness, water resistance, chemical resistance, etc., low specific gravity and low cost.
However, since the impact resistance, particularly the impact strength at low temperatures, is inferior, the purpose of use may be limited. In order to solve this problem, many proposals have been made to blend rubber components such as hydrogenated styrene-butadiene-styrene block copolymer and ethylene-α-olefin copolymer rubber. However, these polypropylene-based resin compositions have improved impact resistance, but have reduced rigidity and molded appearance, which are not practically sufficient. In order to improve these, use of a high molecular weight type ethylene-α-olefin copolymer is considered. However, the use of the high molecular weight type as the rubber component is not practically preferable because the dispersibility in the resin is poor and the fluidity of the obtained composition is further reduced.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problems, and is directed to a polypropylene, an olefin-based elastomer, a hydrogenated block copolymer having a specific structure, and if necessary, an inorganic block copolymer. An object of the present invention is to provide a polypropylene-based resin composition having a good balance of fluidity, rigidity, impact resistance, and molded appearance by blending a filler.

[0004]

That is, the present invention relates to (a) a flexural modulus of 8000 kgf / cm ² (785 M
Pa) or higher and a temperature of 230 ° C., to melt flow rate polypropylene 50-90% is 20 to 300 g / 10 min (ii) total 100 parts by weight of olefinic elastomer 50-10 wt% in weight 2.16kg (C) a polymer block consisting only of 1,3-butadiene
Any one of the polymer blocks consisting solely of
One or both polymer blocks only, and
It has at least two polymer blocks in a molecule, and has a 1,2-bond and a 3,4-bond (hereinafter, referred to as a 1,4-bond) in the polymer block.
Hydrogenation of at least 70% of the olefinically unsaturated bonds in the block copolymer in which the difference between the maximum content and the minimum content of the conjugated diene moiety having "1,2-bonds etc." A hydrogenated block copolymer having a weight-average molecular weight of 1 to 700,000 0.1 to 50 parts by weight (d) an inorganic filler 0 to 50 parts by weight to provide a polypropylene-based resin composition. is there. Less than,
The present invention will be described in detail.

[0005](A) Ingredient  (A) polypropylene contained in the composition of the present invention,
Crystalline polypropylene, homopolymer of propylene
Or ethylene, 1-butene, 1-pentene, 1-
Xen, 1-octene, 2-methyl-1-propene, 3
-Methyl-1-pentene, 4-methyl-1-pentene,
Including α-olefins such as 5-methyl-1-hexene
It is a copolymer. As this copolymer, random copolymer
Polymer, block copolymer, or obtained by multi-stage polymerization
Blends with homopolymers or ordinary blends
It may be a thing. In addition, these polypropylenes are obtained
As a method, it is possible to use a multi-phase catalyst such as a Ziegler-Natta catalyst.
Method using chi-site catalyst or Kaminski catalyst
Such as using a single-site catalyst
However, as the component (A) of the present invention, any polymerization catalyst
Is also preferably used. However, professional
The stereoregularity of the pyrene unit is
Or syndiotactic is the component (A) of the present invention.
Is preferred. In the (a) polypropylene of the present invention
Flexural modulus is 8000kgf / cm²(785MPa)
It is more than 10,000 k
gf / cm²(981-4903MPa), more preferred
11000-80000kgf / cm²(1079
~ 3923 MPa), more preferably 12000-6.
0000kgf / cm²(1177-2942 MPa)
And the melt flow rate (MFR, g / 10 min) is
20-300, preferably 30-200, more preferably
Is 40-150It is. Flexural modulus less than 8000, M
FR20If less, the balance between fluidity and rigidity is poor.
Not preferred.

(Ii) Component The (ii) olefin elastomer used in the present invention is a copolymer of α-olefins such as ethylene, propylene, 1-butene, 1-hexene and 1-octene.
Or copolymers thereof with non-conjugated dienes such as dicyclopentadiene and 5-ethylidene-2-norbornene;
Alternatively, it is an elastomer comprising a homopolymer of a higher α-olefin such as 1-hexene and 1-octene. Among these, ethylene / propylene copolymer, ethylene / propylene
1-butene copolymer, ethylene / propylene / 1-butene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / 1-butene / dicyclopentadiene copolymer, ethylene / propylene / 5-ethylidene- 2-norbornene copolymer, ethylene / 1-butene / 5-ethylidene-2-norbornene copolymer, ethylene / 5-ethylidene-2-norbornene copolymer, ethylene / 1-hexene copolymer, ethylene / 1- Octene copolymer, ethylene / 1-hexene / dicyclopentadiene copolymer, ethylene / 1-hexene / 5-ethylidene-2-norbornene copolymer, ethylene / 1-octene / dicyclopentadiene copolymer, ethylene Ethylene copolymer such as 1-octene-5-ethylidene-2-norbornene copolymer Body is preferable. These olefinic elastomers may be a mixture of two or more. The MFR of the elastomer is not particularly limited, but is preferably 0.1 to 200 g / 10 minutes. still,
The production of the olefin-based elastomer in the present invention is not limited at all, and one using a single-site catalyst and one using a multi-site catalyst are preferably used. In addition, 1-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-1-butene, 2-methyl-1- Pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-
Heptene, 4-methyl-1-hexene, 5-methyl-1
-Hexene, 4,4-dimethyl-1-pentene, 1-decene, etc., and non-conjugated dienes include tricyclopentadiene, 5-methyl-2, 5-norbonadiene, 5-methyl-2-norbornene, -Isopropenyl-2-norbornene, 5-isopropylidene-2-norbornene, 5- (1-butenyl) -2-norbornene, cyclooctadiene, vinylcyclohexene, 1,
5,9-cyclododecatriene, 1,4-hexadiene, 1,6-octadiene, 1,7-octadiene,
Examples thereof include 1,8-nonadiene, 1,9-decadiene, 3,6-dimethyl-1,7-octadiene, and the like. These can be used alone or in combination of two or more.

[0007](C) Ingredient  Hydrogenated block copolymer used as component (c) of the present invention
Coalescence isPolymer block consisting only of 1,3-butadiene
Any of polymer blocks consisting only of styrene and isoprene
Consist of only one or both polymer blocks, and
The polymer blockHaving at least two in the molecule,
Conjugated diene moiety having 1,2-bond etc. in body block
The difference between the maximum and minimum content of is 15% by weightthat's allIs
70% or less of the olefinically unsaturated bond in the lock copolymer
The weight-average molecular weight obtained by hydrogenating the above is 1 to 700,000
It is a hydrogenated block copolymer.

Further, the hydrogenated block used in the present invention
In copolymers, the minimum amount of block copolymer before hydrogenation
Having a 1,2-bond or the likeConjugated diene polymerblock
(Hereinafter referred to as “block A”)
Conjugated diene havingpartAnd the maximum 1,2-
Have a bond, etc.Conjugated diene polymerBlock
Rock B ". ).
It is necessary that the content [b] of the ene portion satisfies [b]-[a] ≧ 15%. As a combination of [a] and [b], for example, [a] ≦ 20%, [b] = 35 to 60% [a] ≦ 20%, [b] ≧ 60% [a] = 30 to 45%, [B] ≧ 60%, and among them, is preferable, and in particular,
Are preferred. When [b]-[a] <15%, impact resistance and rigidity variation
Insufficient sensing is not preferred. Used in the present invention
(C) Block structure of hydrogenated block copolymer before hydrogenation
Can be anything that meets the above requirements
For example, the general formula (AB)_n  (AB)_n-A (BA)_n-B (where n is an integer of 1 or more) and the like.
A-C-B (However,C has a 1,2-bond or the likeContaining conjugated dienes
The structure may be such that the amount [c] is [a] <[c] <[b].

The block copolymer before hydrogenation for obtaining the component (c) is, for example, one in which the polymer molecular chain is extended or branched via a coupling agent residue as shown in the following formula. There may be. _{(A-B) m X (} B-A) m X (A-B-A) m X (B-A-B) m X (A-C-B) m X ( where, A, B, C is The same as above, m is an integer of 2 or more;
X is a coupling agent residue)

As the coupling agent in this case, for example, 1,2-dibromoethane, methyldichlorosilane,
Trichlorosilane, methyltrichlorosilane, tetrachlorosilane, tetramethoxysilane, divinylbenzene, diethyl adipate, dioctyl adipate, benzene-1,2,4-triisocyanate, tolylene diisocyanate, epoxidized 1,2-polybutadiene, Epoxidized linseed oil, tetrachlorogermanium, tetrachlorotin, butyltrichlorotin, butyltrichlorosilane, dimethylchlorosilane, 1,4-chloromethylbenzene, bis (trichlorosilyl) ethane and the like can be mentioned. As the block copolymer before hydrogenation for obtaining the component (c) of the present invention, for example, ABA / A-
B, (AB) ₂ -X / AB, (AB) ₄ -X / A-
B, (AB) ₄ -X / (AB) ₂ -X / AB, (A
-B) ₄ -X / (AB) ₃ -X / (AB) ₂ -X / A
A blend of two or more block copolymers such as -B (however, A, B and X are the same as above) is also preferably used. Further, a blend of two or more components (c), for example, a hydrogenated product of ABA / a hydrogenated product of AB, a hydrogenated product of (AB) ₂ -X / A Hydrogenated product of -B,
(AB) hydrogenated product of _4- X / hydrogenated product of AB, (A-
B) Hydrogenated product of _4- X / (AB) Hydrogenated product of _2- X / AB
Hydrogenated product of (AB) _4- X / (AB) _3- X
Hydrogenated product of (AB) ₂ -X / hydrogenated product of AB (however, A, B and X are the same as above), and the like are also suitable as the component (c) of the present invention. Used.

(C) The content of the block A in the block copolymer before hydrogenation for obtaining the component is 5 to 90% by weight,
Preferably 5-85% by weight, the content of block B is 9
It is 5 to 10% by weight, preferably 95 to 15% by weight.
The content of block A is less than 5% by weight or 90% by weight
If it exceeds 30, the effect of improving the impact resistance of the composition will be reduced. The hydrogenated block copolymer used in the present invention has a weight average molecular weight of 10,000 to 700,000, preferably 2 to 60.
And more preferably 30,000 to 500,000. If it is less than 10,000, the effect of improving the impact resistance in the case of a composition is reduced, while 7
If it exceeds 0,000, the processability decreases, and the molded appearance of the composition deteriorates.

The method for producing the hydrogenated block copolymer of the present invention may be any method. In general, the block copolymer before hydrogenation is subjected to living anion polymerization in an organic solvent using an organic alkali metal compound as an initiator. , And then obtained by performing a hydrogenation reaction. As the organic solvent, a hydrocarbon solvent such as pentane, hexane, heptane, octane, methylcyclopentane, cyclohexane, benzene, xylene, and toluene is used. As the organic alkali metal compound as a polymerization initiator, an organic lithium compound is preferable. As the organic lithium compound, an organic monolithium compound, an organic dilithium compound,
An organic polylithium compound is used. Specific examples of these include ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, phenyl lithium, hexamethylene dilithium, butadienyl lithium, and isoprenyl dilithium. And the like, and are used in an amount of 0.02 to 0.4 part by weight per 100 parts by weight of the monomer.

The content of the conjugated diene compound having a 1,2-bond or the like in the blocks A and B (hereinafter referred to as "content of the 1,2-bond or the like") is controlled by adjusting the content of Lewis bases such as ethers and amines. Specifically, ether derivatives of polyethylene glycol such as diethyl ether, tetrahydrofuran, propyl ether, butyl ether, higher ethers, and even ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, and triethylene glycol dimethyl ether; And tertiary amines such as pyridine, triethylamine and tributylamine, etc., and are used together with the above-mentioned organic solvents.

Further, the polymerization reaction is usually carried out at -30 to +1.
Performed at 50 ° C. Further, the polymerization may be carried out while controlling at a constant temperature, or may be carried out at an elevated temperature. Although any method may be used for forming the block copolymer, generally, in the above-mentioned organic solvent, by using a polymerization initiator such as the above-mentioned alkali metal compound, first, the block A is polymerized, and then the block B is polymerized. It can be a block copolymer containing blocks A and B.

The hydrogenated block copolymer of the present invention is obtained by hydrogenating the block copolymer thus polymerized to thereby hydrogenate the double bond residue of the conjugated diene moiety (c).
Is obtained. That is, the hydrogenated block copolymer of the present invention is obtained by dissolving the block copolymer thus obtained in an inert solvent, at 20 to 150 ° C. and 1 to 100 kg /
It is obtained by hydrogenation in the presence of a hydrogenation catalyst under cm ² G of pressurized hydrogen. At that time, the olefinically unsaturated bond in the block copolymer is 70% or more, preferably 80% or more.
% Or more, more preferably 90% or more, particularly preferably 95% or more. 7
If it is less than 0%, heat resistance and weather resistance are insufficient. Inert solvents used for hydrogenation include hydrocarbon solvents such as hexane, heptane, cyclohexane, benzene, toluene and ethylbenzene, and polar solvents such as methyl ethyl ketone, ethyl acetate, ethyl ether and tetrahydrofuran.

As the hydrogenation catalyst, dicyclopentadienyl titanium halide, nickel organic carboxylate,
Hydrogenation catalyst comprising an organic cobaltate or the like and an organic metal compound of Groups I to III of the Periodic Table, carbon, silica, nickel supported on diatomaceous earth, platinum, palladium, ruthenium, rhenium, rhodium metal catalyst,
Metal catalysts such as cobalt, nickel, rhodium and ruthenium complexes can be used. Also, hydrogenated compounds such as lithium aluminum hydride, p-toluenesulfonyl hydrazide, Zr-Ti-Fe-V-Cr alloy, Zr-Ti-Nb-Fe-V-Cr alloy, LaNi
A hydrogenation reaction using a hydrogen storage alloy such as ₅ can also be mentioned as a method for producing the hydrogenated block copolymer used in the present invention. The hydrogenation rate of the conjugated diene portion is adjusted by changing the amounts of the hydrogenation catalyst and the hydrogenated compound, or the hydrogen pressure and the reaction time during the hydrogenation reaction. The catalyst residue is removed from the hydrogenated block copolymer solution, if necessary, and a phenolic or amine-based antioxidant is added to easily remove the hydrogenated block copolymer from the polymer solution. Can be isolated. Isolation of the hydrogenated block copolymer, for example, in a hydrogenated block copolymer solution,
The method can be carried out by a method of adding acetone or alcohol to precipitate the solution, a method of putting the polymer solution into hot water with stirring, and removing the solvent by distillation. The hydrogenated block copolymer of the present invention can be used as a modified hydrogenated block copolymer by introducing at least one kind of functional group into the hydrogenated block copolymer.

The composition of the present invention comprises (a) a polypropylene, (b) an olefin-based elastomer, and (c) a hydrogenated block copolymer, and has an excellent balance of fluidity, rigidity, impact resistance, and molded appearance. A composition. In the composition of the present invention, the compounding ratios of (a) polypropylene, (b) olefin-based elastomer, and (c) hydrogenated block copolymer are as follows: (a) component 50 to 90% by weight, (b) component 50 to 1
(C) 0.1 to 50 parts by weight, preferably 0.3 to 45 parts by weight, based on a total of 100 parts by weight of 0% by weight. When the component (a) is less than 50% by weight, the rigidity is reduced, and when it exceeds 90 % by weight, the effect of improving the impact resistance of the composition is insufficient, which is not preferable.
If the component (b) is less than 10 % by weight, the effect of improving the impact resistance of the composition is insufficient, and if it exceeds 50% by weight, the rigidity is reduced and the fluidity is insufficient. It is not preferable because the object of the present invention cannot be achieved. further,
When the component (c) is less than 0.1 part by weight based on 100% by weight of the total of the components (a) and (b), the effect of improving the impact resistance of the composition is insufficient. If the amount is more than the weight part, the rigidity is reduced and the object of the present invention cannot be achieved, which is not preferable.

In the composition of the present invention, if necessary,
(D) It is possible to add an inorganic filler as a component. The addition of the component (d) makes it possible to obtain a composition having particularly high rigidity, high rigidity and high fluidity, and excellent impact resistance and molded appearance. In the composition of the present invention, the inorganic filler constituting the component (d) enhances the rigidity of the composition. For example, silica, talc, calcium carbonate, magnesium carbonate, glass fiber, carbon fiber, metal fiber, Glass beads, mica, potassium titanate whiskers, montmorillonite, zinc oxide whiskers, and the like are used, and these are used alone or in combination of two or more. The amount of the component (d) in the composition of the present invention is 50 parts by weight or less, preferably 40 parts by weight or less, more preferably 30 parts by weight or less. When the amount of the component (d) exceeds 50 parts by weight, the impact resistance particularly at a low temperature is greatly reduced, and the fluidity, rigidity, impact resistance,
It is not preferable because the balance of the molded appearance is inferior.

The production of the composition of the present invention is not particularly limited, and a known method can be used. For example, the composition of the present invention can be obtained by kneading the components with various extruders, Banbury mixers, kneaders, rolls, and the like. In the composition using the hydrogenated block copolymer or the component (a) to (d) as the component (c) of the present invention, various additives such as an antioxidant, a heat stabilizer, and an ultraviolet ray may be used, if necessary. An absorbent, a stabilizer such as a copper damage inhibitor, a filler such as carbon, aramid fiber, wood powder, cork powder, cellulose powder, and rubber powder can be compounded and used. Further, the composition of the present invention may be used by blending a softener such as a plasticizer, an oil, or a low molecular weight polymer together with the above additives.

[0020]

EXAMPLES Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to the examples unless it exceeds the gist of the present invention. In the examples, parts and percentages are by weight unless otherwise specified. Various measurements in the examples were based on the following methods. Content of 1,2 -bonds, etc. The content of 1,2-bonds, etc. was calculated by the Hampton method using infrared analysis. Hydrogenation rate The hydrogenation rate of the conjugated diene was 10% in ethylene tetrachloride as a solvent.
Calculated from ⁰ MHz, ¹ H-NMR spectrum. Weight average molecular weight The weight average molecular weight (hereinafter, also referred to as “molecular weight”) was determined by gel permeation chromatography (GPC) in terms of polystyrene. Fluidity 230 ° C, load 2.1 according to JIS K7210
The melt flow rate (MFR) at 6 kg was measured and used as an index of moldability. Rigidity The flexural modulus was measured according to JIS K7203 and used as an index of rigidity. Impact resistance Izod impact strength was measured according to JIS K7110 and used as an index of impact resistance. Molding appearance The molding appearance was visually evaluated according to the following criteria. ：: Good appearance. ×: Poor appearance phenomena such as pearl luster, flow mark, and rough surface are observed.

Reference Examples Various components used in the formulations shown in Examples and Comparative Examples are as follows. Polypropylene A polypropylene (PP-1 to PP-5) having the MFR, flexural modulus and Izod impact strength shown in Table 1.

[Table 1] Olefinic elastomer EP-1: Ethylene / propylene copolymer [EP01NS manufactured by Nippon Synthetic Rubber Co., Ltd.] EP-2: Ethylene / propylene copolymer [EP912 manufactured by Nippon Synthetic Rubber Co., Ltd.] EB-1: Ethylene / 1 -Butene copolymer [Nippon Synthetic Rubber Co., Ltd. EBM2041P] EB-2: Ethylene / 1-butene copolymer [Mitsui Petrochemical Co., Ltd. Tuffmer A4085] EH-1: Ethylene / 1-hexene copolymer Combined [EXACT2010, manufactured by Exxon Chemical] EH-2: Ethylene / 1-hexene copolymer [EXACT2009, manufactured by Exxon Chemical] EO-1: Copolymer of ethylene / 1-octene [ENGAGE EG8100, manufactured by Dow Chemical] EO-2 : Ethylene / 1-octene copolymer [ENGAGE EG manufactured by Dow Chemical 200]

The hydrogenated block copolymer in Reference Example 1 (preparation of hydrogenated block copolymer) degassing a 10 liter autoclave, dehydrated cyclohexane 5 kg, after charged with 1,3-butadiene 300 g, tetrahydrofuran 0. 25 g and 0.50 g of n-butyllithium were added to carry out constant isothermal polymerization at a polymerization temperature of 80 ° C. After the polymerization conversion reached almost 100%, the reaction solution was cooled to 40 ° C., 75 g of tetrahydrofuran and 700 g of 1,3-butadiene were added, and the temperature was raised by polymerization. After the polymerization was completed, the amount of living Li was measured and found to be 3.1 mmol. 0.56 g of benzophenone was added to the system and stirred for 10 minutes.
From the change in the color of the polymer liquid, it was confirmed that there was no living lithium terminal lithium as a living anion.
Next, 3.51 g of benzophenone dissolved in 20 ml of cyclohexane and 1.20 g of n-butyllithium were previously reacted under a nitrogen atmosphere for 10 minutes, and a reaction product was further charged. Then, bis (cyclopentadienyl) titanium dichloride was added. A component in which 52 g and 1.51 g of diethyl aluminum chloride dissolved in 10 ml of toluene were mixed in advance in a nitrogen atmosphere was charged into an autoclave and stirred. Hydrogen gas was supplied at a pressure of 8 kg / cm ² G, and a hydrogenation reaction was performed at 90 ° C. for 1.5 hours. The hydrogenation rate of the obtained hydrogenated polymer was 98%, and the molecular weight was 301,000. The 1,2-butadiene block had a 1,2-vinyl bond content of 15% as measured at the end of the first-stage 1,3-butadiene block polymerization.
As a result of calculating from the 1,2-vinyl bond content measured at the end of the polymerization of 1,3-butadiene in the first stage and the 1,2-vinyl bond in the first stage, the 1,3-butadiene block in the second stage was obtained. Had a 1,2-vinyl bond content of 80%. Reference Examples 2 to 14 By the same method as in Reference Example 1, varying the monomer species, the amount of the monomer, the amount of the catalyst, the polymerization time, the polymerization temperature, etc. so as to obtain each hydrogenated block copolymer in Tables 2 to 4. Produced by Tables 2 to 4 show these results.

[Table 2]

[Table 3]

[Table 4]

Examples 1 to 5 and Comparative Example 1 The hydrogenated block copolymer (S-
8), polypropylene, and an olefin-based elastomer were mixed at a weight ratio shown in Table 5 using a 4-liter Banbury kneader. The mixed composition was cut into square pellets after forming a sheet, and a test piece for evaluating physical properties was prepared by injection molding. Table 5 shows the results of the physical property evaluation.
Each of these examples is a composition using a hydrogenated block copolymer within the scope of the present invention, has excellent low-temperature impact resistance, and has excellent fluidity, rigidity, impact resistance, and molded appearance. The balance is good. On the other hand, Comparative Example 1 is an example in which the hydrogenated block copolymer was not used. However, although the fluidity was high, the impact resistance and the rigidity were extremely poor, and the balance of physical properties was lacking as a whole.

[Table 5] Examples 6 to 53 In the same manner as in Example 1, the composition of the hydrogenated block copolymer obtained in Reference Examples 1 to 11, the polypropylene, the olefin-based elastomer, and the talc in the weight ratios shown in Tables 6 to 13 were used. A product was prepared and each physical property was evaluated. Table 6 shows the results
To 13 are shown. All of these examples are compositions using the hydrogenated block copolymer within the scope of the present invention, and are particularly excellent in rigidity and fluidity, and these fluidity, rigidity and impact resistance, molded appearance and It is an excellent balance.

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

[Table 12]

[Table 13] Comparative Examples 2 to 6 Injection molded articles were produced in the same manner as in Example 1, using the hydrogenated block copolymers obtained in Reference Examples 12 to 15, and their physical properties were evaluated. Table 14 shows the results. A composition using a hydrogenated block copolymer that does not satisfy the requirements of the present invention lacks the balance of fluidity, rigidity, impact resistance, and molded appearance. Comparative Example 6 was an example in which the hydrogenated block copolymer was not used, and the fluidity and impact resistance were poor, and the fluidity, impact resistance and rigidity, and the balance of the molded appearance were lacking. .

[Table 14]

[0024]

According to the present invention, polypropylene having excellent balance of fluidity, rigidity, impact resistance and molded appearance is obtained by blending polypropylene, an olefin-based elastomer and a hydrogenated block copolymer having a specific structure. A resin composition can be obtained. The composition of the present invention comprises:
Used as various molded products by injection molding, extrusion molding, vacuum molding, etc., taking advantage of its excellent characteristics, automotive interior and exterior materials, various electric and electronic parts, housings, industrial parts, stationery, medical materials, films, It can be widely used for sheet products.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuhiko Takemura 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (72) Inventor Yoichi Kamoshida 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-7-48485 (JP, A) JP-A-6-306220 (JP, A) JP-A-3-128957 (JP, A) Product catalog "Asahi Kasei Polypro" 1992 March (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 23/00-23/36

Claims (1)

(57) [Claims] (1) The flexural modulus is 8000 kgf / c
m ² (785 MPa) or more, temperature 230 ° C., load 2.
Melt flow rate at 16 kg is 20-300 g
/ Polypropylene 50-90% by weight is 10 min, and (ii) an olefinic elastomer 50-10 wt% of the total 100 parts by weight consists of only (c) 1,3-butadiene polymer block
Any one of the polymer blocks consisting solely of
One or both polymer blocks only, and
A difference between the maximum content and the minimum content of the conjugated diene moiety having 1,2- and 3,4-bonds in the polymer block having at least two polymer blocks in the molecule is 15% by weight or more. The weight average molecular weight obtained by hydrogenating 70% or more of the olefinically unsaturated bonds in the block copolymer is 1
0.1 to 50 parts by weight of a hydrogenated block copolymer of from 700,000 to 700,000. (D) A polypropylene resin composition containing 0 to 50 parts by weight of an inorganic filler.