JPH10298242A - Crosslinked ethylene/alpha-olefin/aromatic vinyl compound copolymer elastomer and polypropylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crosslinked ethylene/α-olefin/arom. vinyl compd. copolymer elastomer capable of improving the whitening resistance and moldability of a polypropylene resin and to provide a polypropylene resin compsn. modified with the same. SOLUTION: This crosslinked copolymer elastomer has such characteristics that the number of carbon atoms of the α-olefin is 4-20; the content of the α-olefin is 30 mol% or higher; the crystal melting peak is not observed with a differential scanning calorimeter; and the content of the arom. vinyl compd. is 0.01-30 mol%. The polypropylene resin comps. comprises 1-80 wt.% crosslinked copolymer elastomer and 99-20 wt.% polypropylene resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a crosslinked product of an ethylene / α-olefin / aromatic vinyl compound copolymer elastomer capable of improving the whitening resistance and moldability of a polypropylene resin, and The present invention relates to a polypropylene resin composition modified thereby.

[0002]

2. Description of the Related Art Polypropylene resins are well known as one of high polymer materials having excellent fluidity. However, drawdown at the time of molding is severe, which may cause problems in vacuum, air pressure, film forming and the like. Many. These phenomena originate from the low melt tension, and for the same reason, the blow moldability is not excellent.

In order to improve such properties, techniques such as broadening the molecular weight distribution or adding branched low-density polyethylene (LDPE) are often employed. In any case, the modifying effect is small. There was a desire for improvement.
Also, the addition of LDPE has a serious problem that the whitening resistance of the polypropylene resin is significantly deteriorated, and a modifier that suppresses whitening has been strongly desired.

[0004]

SUMMARY OF THE INVENTION Under such circumstances,
The present inventors have found that (a) the α-olefin has 4 to 20 carbon atoms.
(B) the α-olefin content is greater than 65% by weight and 95% by weight or less, and (c) the density at 23 ° C. is 0.8% or less.
A resin composition comprising an ethylene / α-olefin-based copolymer elastomer and a polypropylene-based resin that satisfies the condition that the melting point is less than 8 g / cm ³ and (d) no crystal melting peak is observed by the DSC method is heat resistance, whitening resistance (Japanese Unexamined Patent Publication No. 7-017208).

However, this resin composition has a problem that the surface becomes sticky as the blend ratio of the ethylene / α-olefin copolymer elastomer increases, and there is a possibility that the commercial value may be impaired.

[0006] Further, we have repeated studies and have converted an ethylene / α-olefin / aromatic vinyl compound copolymer elastomer having an α-olefin of 4 or more carbon atoms and a copolymerization amount of 30 mol% or more into a polypropylene resin. It has been found that when blended, the polypropylene resin has excellent whitening resistance and low surface tackiness (JP-A-7-31635).
5, 7-316356). However, the melt tension of this resin composition is small, and the moldability such as film, blow, vacuum, and pressure forming has not been sufficiently improved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an ethylene.alpha.
A crosslinked product of an olefin / aromatic vinyl compound copolymer elastomer and a polypropylene resin composition modified thereby.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, completed the present invention. That is, the present invention provides the following (a) to (d)
The present invention relates to a crosslinked product of an ethylene / α-olefin / aromatic vinyl compound copolymer elastomer having the following characteristics, and a polypropylene resin composition modified thereby.

(A) Carbon number of α-olefin: 4 or more and 20 or less (b) α-olefin content: 30 mol% or more (c) Crystal melting peak by differential scanning calorimeter: not observed (d) Aromatic Vinyl compound content: 0.01 mol% or more 3
0 mol% or less The details will be described below.

The ethylene α- used in the present invention
The α-olefin of the olefin / aromatic vinyl compound copolymer elastomer has 4 to 20 carbon atoms and includes, for example, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1
-Dodecene, 1-tridecene, 1-tetradecene, 1-
Pentadecene, 1-hexadecene, 1-heptadecene,
Examples thereof include 1-octadecene, 1-nonadecene, and 1-eicosene, and one or more of these are used. Among them, 1-butene, 1-heptene, 1-hexene, 1-octene and the like are preferable from the viewpoint of availability.

The ethylene α- used in the present invention
The α-olefin content of the olefin / aromatic vinyl compound copolymer elastomer is 30 mol% or more, preferably 30 mol% or more and 99 mol% or less. If the α-olefin content is less than 30 mol%, the resin composition obtained by adding 1 to 80% by weight to the polypropylene resin after crosslinking may have poor whitening resistance and poor moldability. When the α-olefin content is 99 mol% or less, there is no possibility that the decomposition reaction will preferentially proceed in the crosslinking reaction by peroxide or electron beam.

The ethylene α- used in the present invention
Examples of the aromatic vinyl compound of the olefin / aromatic vinyl compound-based copolymer elastomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene,
o, p-dimethylstyrene, o-ethylstyrene, m-
Ethylstyrene, p-ethylstyrene, o-chlorostyrene, p-chlorostyrene, α-methylstyrene and the like can be mentioned.

The content of the aromatic vinyl compound is in the range of 0.01 mol% or more and 30 mol% or less, especially 0.1 to 1 mol%.
It is preferably in the range of 5 mol%. If the amount of the aromatic vinyl compound exceeds 30 mol%, the low-temperature properties may be degraded, and if it is less than 0.01 mol%, surface tackiness may occur.

Further, the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer used in the present invention may be copolymerized with a non-conjugated diene monomer, if necessary. Examples of the non-conjugated diene monomer include 1,4-pentadiene, 1,4-hexadiene, 4-methyl-1,5-heptadiene,
Methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-isopropenyl-2-norbornene,
2,5-norbonadiene, 1,6-cyclooctadiene, 2-ethylene-2,5-norbonadiene, 2-isopropenyl-2,5-norbonadiene, dicyclopentadiene, 1,6-octadiene, 1,7-octadiene , Esters of tricyclopentadiene and dihydrodicyclopentadienyloxyethylene with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and the like, but are not limited thereto. is not. And one or two of these
More than one species is used.

When copolymerizing a non-conjugated diene monomer,
The copolymerization amount of the non-conjugated diene monomer is desirably 30 or less in iodine value. If the iodine value exceeds 30, the cold resistance of the crosslinked product of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer and the composite material of the crosslinked product and the polypropylene resin may be deteriorated. The iodine value can be measured by a known method (for example, "Rubber Test Method", p. 657, edited by The Japan Rubber Association, (1)
963)).

The ethylene / α- used in the present invention
The olefin / aromatic vinyl compound copolymer elastomer preferably has a density at 23 ° C. of less than 0.91 g / cm ³ . The density of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer is 0.91 g /
When the molecular weight is less than ³ cm ^3, it is preferable to add a crosslinked product of an ethylene / α-olefin / aromatic vinyl compound-based copolymer elastomer to a polypropylene-based resin because the melt tension of the polypropylene-based resin is increased and the moldability is improved.

The ethylene α- used in the present invention
The olefin / aromatic vinyl compound copolymer elastomer is characterized in that no crystal melting peak is observed by a differential scanning calorimeter (abbreviated as DSC). When an ethylene / α-olefin / aromatic vinyl compound-based copolymer showing a crystal melting peak is used, the resin composition obtained by adding 1 to 80% by weight to a polypropylene-based resin after cross-linking is difficult to whiten and a molding process. There is a possibility that the property is inferior.

Although the molecular weight of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer of the present invention is not particularly limited, the number average molecular weight measured by gel permeation chromatography (GPC) is in terms of polyethylene. It is preferable that it is 5,000 to 1,000,000 because handling is easy.

The method for producing the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer used in the present invention is not particularly limited. For example, the copolymer may be a random copolymer using a metallocene-based catalyst or the like, or a triblock copolymer in which a chain of an aromatic vinyl compound exists at a molecular terminal. It can also be obtained by hydrogenating a styrene / butadiene copolymer rubber.

The crosslinked product of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer of the present invention is obtained by crosslinking the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer with a peroxide or an electron beam. It is obtained by doing.

In the case of crosslinking by adding a peroxide, the amount of the peroxide to be added is not limited and may be appropriately determined depending on the desired reforming effect. However, the ethylene / α-olefin / aromatic vinyl compound copolymer may be used. 20 ppm or more with respect to coalescence 500
It is preferably at most 00 ppm, and by setting the content within this range, the self-adhesion rate of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer decreases,
Handling becomes easy, and stickiness of the modified polypropylene resin composition is reduced.

The heating conditions after the addition of the peroxide are not particularly limited, and are determined according to the peroxide and the crosslinking aid used.
The temperature is desirably set to not less than 300 ° C.

The peroxide used in the present invention is t.
-Butyl peroxide, di (t-butyl) peroxide, t-butylperoxy-isopropyl carbonate, t-butylcumyl peroxide, t-butylperoxybenzoate, dicumyl peroxide, cumene peroxide, benzoyl peroxide, Cyclohexanone peroxide, diisopropylbenzene peroxide, 2,5-dimethylhexane-2,5-diperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,2,5- Dimethyl-
2,5-di (t-butyl) peroxyhexane, n-butyl-4,4-bis (t-butylperoxy) hexane, 3,3,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl Peroxide, p-
Chlorobenzoyl peroxide, 1,1-bis (t-
Butylperoxy) -3,3,5-trimethylcyclohexane, 2,2′-bis (t-butylperoxy) -p
-Diisopropylbenzene, 1,3-bis (t-butylperoxy-isopropyl) benzene, and the like, which are used alone or in combination.

In the present invention, it is also possible to use a crosslinking accelerator together. Examples of the crosslinking accelerator include guanidine derivatives such as N, N-diphenylguanidine, N, N-di (o-tolyl) guanidine, N, N-o-tolylguanidine; N, N-dibutylthiourea, N, N '-
Thiourea such as diethylthiourea, dilaurylthiourea, 2-mercaptoimidazoline, trimethylthiourea, tetramethylthiourea; xanthogellate such as zinc dibutylxanthogenate, sodium isopropylxanthogenate, zinc isopropylxanthogenate; dimethyldithiocarbamic acid Zinc, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate,
Zinc ethylphenyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc dibenzyldithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium dibutyldithiocarbamate, copper dimethyldithiocarbamate, terylium diethyldithiocarbamate, piperidinium pentamethylene Dithiocarbamates such as dithiocarbamate, pipecoline piperidimethyldithiocarbamate and iron dimethyldithiocarbamate; aldehyde ammonia-based compounds such as hexamethylenetetramine, acetaldehyde aniline and butyraldehyde aniline; mercaptobenzothiazole;
Mercaptobenzothiazole sodium salt, dibenzothiazyl disulfide, 2- (4-morpholinodithio)
Benzothiazole, 2- (2,4-dinitrophenyl)
Thiazole compounds such as mercaptobenzothiazole; thiuram sulfide such as tetramethylthiuram monosulfide, tetraethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide; mercapto Thiazole-based compounds such as benzothiazole, dibenzothiazyl disulfide, zinc 2-mercaptobenzothiazole; N-cyclohexyl-
2-benzothiazolesulfenamide, N-oxydiethylene-2-benzothiazolesulfenamide, N
Examples include, but are not limited to, sulfenamide compounds such as -t-butylbenzothiazolesulfenamide. These crosslinking accelerators may be used alone or in combination of two or more.

Further, it is possible to use a co-crosslinking agent in the present invention. Examples of the co-crosslinking agent include P-quinone dioxime, P-P dibenzoylquinone dioxime,
N-methyl-N'-4-dinitrosoaniline, dinitrosobenzene, lauryl methacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane Trimethacrylate, diaryl fumarate, diaryl phthalate, tetraaryloxyethane, triaryl cyanurate, aryl methacrylate, maleimide, phenylmaleimide, N, N'-m-phenylenebismaleimide, maleic anhydride, itaconic acid, divinylbenzene , Diarylmelamine, diphenylguanidine, divinyl adipate, vinyl toluene, 1,2-polybutadiene, liquid styrene-butadiene Copolymer rubber, dipentamethylenethiuram pentasulfide, mercaptobenzthiazoles, sulfur and the like, are used as necessary one or more of these.

When a crosslinking accelerator or a co-crosslinking agent is used, the amount thereof is 5,000 for the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer, respectively.
It is desirable that the content be 0 ppm or less. 50,000 ppm
If it exceeds 300, the surface of the crosslinked product of the obtained ethylene / α-olefin / aromatic vinyl compound copolymer elastomer and the surface of the polypropylene resin composition modified thereby may be remarkably sticky.

It is also possible to use a crosslinking accelerator such as zinc white, activated zinc white, surface-treated zinc white, zinc carbonate, litharge and magnesium oxide, and a dispersant at the time of crosslinking.

When the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer is cross-linked by using an electron beam, it is preferable that the irradiation amount of the electron beam be 1 kGray or more and 100 kGray or less. This reduces the self-adhesion rate of the ethylene / α-olefin / aromatic vinyl compound-based copolymer elastomer and facilitates handling, and the resin composition obtained by adding to the polypropylene-based resin reduces stickiness, In addition, the effect of improving the moldability due to the increase in the melt tension becomes remarkable. As the polypropylene resin used in the present invention, a generally used crystalline polypropylene resin can be used. For example, propylene homopolymer, ethylene content of 0.5
Propylene / ethylene random copolymer having an ethylene content of 0.5 to 12% by weight and an α-olefin content of 0.5 to 20% by weight.
α-olefin terpolymer, ethylene content of 1 to 6
Examples thereof include 0% by weight of impact polypropylene and a crystalline polypropylene resin having a syndiotactic structure, and one or more of these are used.

The melt flow rate of the polypropylene resin is not particularly limited, but a melt flow rate of 0.01 to 100 g / 10 minutes at 230 ° C. under a load of 2.16 kg is preferably used.

The blend ratio of the crosslinked product of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer and the polypropylene resin is not particularly limited,
The crosslinked product (A) of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer (A) and the polypropylene resin (B) have a weight ratio of A / B of 1/99 to 80/20. If the amount of the crosslinked product (A) of the ethylene / α-olefin copolymer elastomer is less than this range, the resin modifying effect may not be exhibited, and if it is too large, the rigidity may be impaired.

The crosslinked product of the ethylene / α-olefin / aromatic vinyl compound-based copolymer elastomer of the present invention and the polypropylene-based resin composition modified thereby may, if necessary, contain a paraffin-based softener, a naphthene-based Softener, aroma softener, vaseline, carbon black, calcium carbonate, mica, talc, silica, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, bentonite, sericanite, zeolite, nepheline sinite, attapulgite, wollastonite , Ferrite, calcium silicate, magnesium carbonate, dolomite, antimony trioxide, titanium oxide, iron oxide, molybdenum disulfide, graphite, gypsum, glass beads,
Glass powder, glass balloon, glass fiber,
Inorganic fillers such as quartz and quartz glass and organic or inorganic pigments can also be blended. In addition, crystal nucleating agents, clarifying agents, anti-blocking agents, release agents, antistatic agents, slip agents, anti-fog agents, lubricants, heat stabilizers, ultraviolet stabilizers, light stabilizers, weather resistance stabilizers, foaming agents If necessary, a fungicide, a rust preventive, an ion trap, a flame retardant, a flame retardant auxiliary, etc. may be added.

Further, another resin or rubber is blended with the crosslinked product of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer of the present invention and the polypropylene resin composition modified thereby. It is also possible. In this case, a compatibilizer may be added as a further component as needed. Such other resins include linear high-density polyethylene, linear low-density polyethylene, branched low-density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer, poly (1- Butene), polyamide, polyester, poly (4-methyl-1-pentene), styrene / isoprene / styrene block copolymer, styrene / ethylene butene / styrene block copolymer, styrene / ethylene propylene / styrene block copolymer, Examples include styrene / butadiene / styrene block copolymers and polyolefin-based thermoplastic elastomers.
Examples of the rubber include natural rubber, acrylonitrile butadiene rubber, butadiene rubber, isoprene rubber, styrene butadiene rubber and hydrogenated products thereof, silicone rubber, polynorbornene rubber, polyhexene rubber, ethylene propylene rubber, ethylene propylene diene. Examples include random copolymer rubber and chloroprene rubber. Further, examples of the compatibilizer include adhesive polymers such as acid-modified polyolefin and saponified EVA, and block and graft copolymers typified by polyolefin / polyamide graft or block copolymer.

The crosslinked product of the ethylene / α-olefin / aromatic vinyl compound-based copolymer elastomer of the present invention can be added to the polypropylene resin by any method. In order to improve the properties, it is preferable to perform melt blending using a kneader, a roll, a Banbury mixer, a single-screw and twin-screw extruder, or the like.

The polypropylene resin composition of the present invention can be prepared by blending a polypropylene resin and an ethylene / α-olefin / aromatic vinyl compound copolymer elastomer in advance and then adding a peroxide while performing melt kneading. Things are obtained.

The polypropylene resin composition modified by the crosslinked product of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer of the present invention can be used for film, vacuum, air pressure, blow, calender, transfer, injection, It is molded by any molding method such as compression, profile extrusion, and spinning, but is particularly excellent in film, vacuum, compressed air, blow, and calender moldability requiring melt tension.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to examples, but these are only illustrative and not restrictive. Various measurements and ethylene and α in the examples
-The synthesis of the olefin / aromatic vinyl compound copolymer elastomer was performed by the following method. (ethylene·
Measurement of α-olefin and aromatic vinyl compound content of α-olefin / aromatic vinyl compound copolymer elastomer) 100 MHz, ¹ H-N in o-dichlorobenzene as solvent
MR spectrum (JNM GX40 manufactured by JEOL Ltd.)
0) Calculated by measurement.

(Measurement of molecular weight) Using o-dichlorobenzene as a solvent, gel permeation chromatography at 140 ° C. (150C type GPC manufactured by Millipore Co., Ltd.)
The number average molecular weight was determined in terms of polyethylene.

Synthesis Example 1 of Ethylene / α-Olefin / Aromatic Vinyl Compound Copolymer Elastomer To a 5 l autoclave, 750 ml of toluene, 150 ml of styrene and 600 ml of 1-butene were added, and the ethylene was adjusted to 16 kg / cm ^2. Was introduced. Next, toluene (10 ml), methylaluminoxane (5 mmol) and (dimethyl (t-butylamide) (tetramethyl-η5-cyclopentadienyl) silane) dichloride titanium 5 μmo were synthesized by a known method in another reaction vessel.
After the mixture was stirred for 20 minutes, the mixture was introduced into an autoclave and polymerization was started. This polymerization was carried out at 90 ° C. for 20 minutes while maintaining the ethylene pressure at 16 kg / cm ² . After the completion of the polymerization, the polymer was washed with a large amount of ethanol, and dried at 60 ° C. for 12 hours under reduced pressure. As a result, a styrene content of 2 mol% and a 1-butene content of 47 mol%
32 g of an ethylene / 1-butene / styrene copolymer elastomer was obtained. This copolymer had a number average molecular weight of 3000.
0, iodine value is 0, density is 0.88 g / cm ³ ,
No crystal melting peak was observed by DSC measurement.

Example 1 The ethylene / 1-butene / styrene copolymer elastomer obtained in Synthesis Example 1 was added to dicumyl peroxide 5000p
pm, a hindered phenol-based stabilizer (trade name: Irganox 1010, manufactured by Ciba-Geigy) and a phosphorus-based stabilizer (trade name: Irgafos 168, manufactured by Ciba-Geigy) as a heat stabilizer, 1000 ppm each, and calcium stearate as a lubricant. Add 5000 ppm,
Using a Labo Plastomill (manufactured by Toyo Seiki Seisakusho) having an internal volume of 30 ml, the mixture was kneaded at 200 rpm and 200 rpm for 3 minutes to obtain a crosslinked ethylene / 1-butene / styrene copolymer elastomer.

3.75 g of a crosslinked product of the ethylene / 1-butene / styrene copolymer elastomer and propylene homopolymer (manufactured by Chisso Corporation, trade name: Chisso Polypro, grade K1008, MFR 10 g / 10 min, 230 ° C.,
21.25 g) (2.16 kg load) was melt-blended at 200 ° C. for 5 minutes at 60 rpm in a 30 ml internal volume Labo Plastomill. Thereafter, the obtained resin composition was pressurized at 230 ° C. for 10 minutes using a press molding machine, and then cooled at 30 ° C. to obtain a molded product having a thickness of 1 mm. This press-formed product was finely cut to obtain a sample for measuring the melt tension.

Example 2 Instead of a propylene homopolymer, an ethylene / propylene random copolymer (manufactured by Chisso Corporation, trade name: Chisso Polypro, grade K8017, MFR 8 g / 10 min, 2
30 ° C, 2.16 kg load, ethylene content 3.2 wt%)
A molded article and a sample were obtained in the same manner as in Example 1 except that was used.

Synthesis Example 2 of Ethylene / α-Olefin / Aromatic Vinyl Compound Copolymer Elastomer To a 21 liter autoclave, 250 ml of toluene, 50 ml of styrene and 300 ml of 1-hexene were added, and ethylene was introduced to 16 kg / cm ^2. did. Next, in another reaction vessel, 10 ml of toluene and 5 mmol of methylaluminoxane were synthesized by a known method (dimethyl (t
-Butylamido) (tetramethyl-η5-cyclopentadienyl) silane) dichloride titanium (5 μmol) was added, and the mixture was stirred for 20 minutes and then introduced into an autoclave to start polymerization. This polymerization was carried out at 90 ° C. for 30 minutes while maintaining the ethylene pressure at 16 kg / cm ² .

After completion of the polymerization, the polymer was washed with a large amount of ethanol and dried at 60 ° C. for 12 hours under reduced pressure. As a result, the styrene content was 2 mol% and the 1-hexene content was 34
30 g of a mol% ethylene / 1-hexene / styrene copolymer elastomer was obtained. This copolymer had a number average molecular weight of 54000, an iodine value of 0, and a density of 0.87 g / cm ^3.
In addition, no crystal melting peak was observed by DSC measurement.

Example 3 The ethylene / 1-butene / styrene copolymer elastomer used in Example 1 was replaced with the ethylene / butene / styrene copolymer obtained in Synthesis Example 2.
A molded product and a sample were obtained in the same manner as in Example 1 except that a 1-hexene-styrene copolymer elastomer was used.

Example 4 In place of the ethylene / 1-butene / styrene copolymer elastomer used in Example 1, hydrogenated styrene-butadiene rubber (4 mol% of styrene and 46 mol% of 1-butene) (J
A molded product and a sample were obtained in the same manner as in Example 1 except that Dynalon D1320P (trade name, manufactured by SR Corporation, number average molecular weight 95,000, iodine value 0, density 0.89 g / cm ³ ) was used. Was.

Example 5 21.25 g of the propylene homopolymer obtained in Example 1 and 3.75 g of the ethylene / 1-butene / styrene copolymer elastomer obtained in Synthesis Example 1 were previously prepared in a Labo Plastomill at 200 ° C. and 60 rpm. After melt blending for a minute,
5000 ppm of dicumyl peroxide based on the ethylene / 1-butene / styrene copolymer elastomer, 1000 ppm of a hindered phenol-based stabilizer and 1000 ppm of a phosphorus-based stabilizer as heat stabilizers, and 5000 ppm of calcium stearate as a lubricant, Melt blended for 5 minutes. Two minutes before the end of kneading, 0.025 g of a hindered phenol-based stabilizer and 0.025 g of a phosphorus-based stabilizer were added as heat stabilizers. Thereafter, the obtained resin composition was molded in the same manner as in Example 1 to obtain a molded product and a sample.

Comparative Example 1 The propylene homopolymer used in Example 1 was 25
g and press molded in the same manner as in Example 1 except that the crosslinked product of ethylene / 1-butene / styrene copolymer elastomer was not added to obtain a molded product and a sample. Comparative Example 2 Obtained in Synthesis Example 1 A molded article and a sample were obtained in the same manner as in Example 1 except that the ethylene / 1-butene / styrene copolymer elastomer was used without being crosslinked with a peroxide.

Comparative Example 3 Instead of a crosslinked product of an ethylene / 1-butene / styrene copolymer elastomer, a branched low-density polyethylene (trade name: Petrocene 286, manufactured by Tosoh Corporation, MFR 1.5 g /
A molded article and a sample were obtained in the same manner as in Example 1 except that 10 minutes, 190 ° C. and a load of 2.16 kg) were added.

Comparative Example 4 The procedure of Example 1 was repeated, except that the ethylene-propylene random copolymer used in Example 2 was changed to 25 g, and a cross-linked ethylene / 1-butene / styrene copolymer elastomer was not added. Press molding was performed to obtain a molded product and a sample.

Synthesis Example 3 of Ethylene / α-Olefin Copolymer Elastomer In a 5-liter autoclave, 1000 ml of toluene was added.
And 1-butene (500 ml) were added, and the temperature was raised to 40 ° C. Further, ethylene was introduced so that the total pressure became 8 kg / cm ² . Next, 10 m of toluene was placed in another reaction vessel.
l, 3 mmol of methylaluminoxane, (dimethyl (t
-Butylamido) (tetramethyl-η5-cyclopentadienyl) silane) dichloride titanium (5 μmol) was added, and the mixture was stirred for 20 minutes and then introduced into an autoclave to start polymerization. This polymerization is carried out at a total pressure of 8k.
g / cm ² , and ethylene was continuously introduced.
Performed at 0 ° C. for 30 minutes.

After the completion of the polymerization, the polymer was washed with a large amount of ethanol and dried at 60 ° C. for 12 hours under reduced pressure. As a result, ethylene 1- having a 1-butene content of 56 mol%
44 g of a butene copolymer elastomer was obtained. The number average molecular weight is 108000, the iodine value is 0, and the density is 0.88 g /
cm ³ , and no crystal melting peak was observed by DSC measurement.

Comparative Example 5 The procedure of Example 1 was repeated except that the ethylene / 1-butene / styrene copolymer elastomer obtained in Synthesis Example 3 was used instead of the ethylene / 1-butene / styrene copolymer elastomer. A molded article and a sample were obtained.

Comparative Example 6 A molded product and a sample were obtained in the same manner as in Example 4, except that the hydrogenated styrene / butadiene copolymer rubber used in Example 4 was used without being crosslinked with a peroxide. . As described above, the molded articles obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were evaluated by the following methods. Table 1 shows the results.

(Bending Whitening Test) A 1 mm thick plate was
It was cut into a size of 20 mm × 20 mm and bent at 180 °, and the degree of whitening was visually observed.

(Surface Adhesion) A 1 mm thick plate was
The sheet was cut into a piece having a size of × 20 mm, and two of the pieces were stacked and left in a constant temperature room at 80 ° C. under a load of 1 kg for 3 days. Thereafter, this was peeled off again, and the surface condition of the adhesive surface was visually observed.

(Melt Tension) The melt tension, which is a measure of film, vacuum, compressed air, and blow moldability, was evaluated using a Capillograph (manufactured by Toyo Seiki Seisakusho). Barrel temperature 190 ° C,
The barrel inner diameter is 9.55 mm, and the L / D of the die is 2.95.
/ 8, with a cylinder descending speed of 10 mm / min and a take-up speed of 10 m / min.

As can be seen from Table 1, the ethylene
The polypropylene resin composition obtained by adding a crosslinked product of an α-olefin / aromatic vinyl compound copolymer elastomer to a polypropylene resin has excellent whitening resistance, excellent moldability, and improved surface stickiness. At the same time, the drawdown is greatly suppressed by the increase in the melt tension, and the material is excellent in blow, film, vacuum and air pressure moldability.

[0058]

[Table 1]

[0059]

As described above, as described above, the ethylene
A polypropylene resin composition obtained by adding 1 to 80% by weight of a crosslinked product of an α-olefin / aromatic vinyl compound copolymer elastomer to a polypropylene resin has excellent whitening resistance and moldability.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 8, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

The method for producing the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer used in the present invention is not particularly limited. For example, the copolymer may be a random copolymer using a metallocene-based catalyst or the like, or a triblock copolymer in which a chain of an aromatic vinyl compound exists at a molecular terminal.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Deleted

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction contents]

Example 4 21.25 g of the propylene homopolymer obtained in Example 1 and 3.75 g of the ethylene / 1-butene / styrene copolymer elastomer obtained in Synthesis Example 1 were previously prepared in a Labo Plastomill at 200 ° C. and 60 rpm. After melt blending for a minute,
5000 ppm of dicumyl peroxide based on the ethylene / 1-butene / styrene copolymer elastomer, 1000 ppm of a hindered phenol-based stabilizer and 1000 ppm of a phosphorus-based stabilizer as heat stabilizers, and 5000 ppm of calcium stearate as a lubricant, Melt blended for 5 minutes. Two minutes before the end of kneading, 0.025 g of a hindered phenol-based stabilizer and 0.025 g of a phosphorus-based stabilizer were added as heat stabilizers. Thereafter, the obtained resin composition was molded in the same manner as in Example 1 to obtain a molded product and a sample.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0053

[Correction method] Deleted

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction contents]

[0058]

[Table 1]

Claims (2)

[Claims] 1. A crosslinked product of an ethylene / α-olefin / aromatic vinyl compound copolymer elastomer having the following characteristics (a) to (d): (A) carbon number of α-olefin: 4 or more and 20 or less (b) content of α-olefin: 30 mol% or more (c) crystal melting peak by differential scanning calorimeter: not observed (d) content of aromatic vinyl compound : 0.01 mol% or more 3
0 mol% or less 2. A crosslinked product of the ethylene / α-olefin / aromatic vinyl compound copolymer elastomer according to claim 1 in an amount of 1 to 80% by weight, and a polypropylene resin in an amount of 99 to 2%.
A polypropylene resin composition comprising 0% by weight.