JPH1053687A - Propylene-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polypropylene-based resin composition that has excellent in pact resistance and coatability, and capability of flow mark inhibition. SOLUTION: This polypropylene-based resin composition comprises (A) polypropylene-based polymer having a propylene-ethylene block copolymer that has a 5-100g/10min MFR(melt flow rate), 15-60wt.% of xylene extractable content at 20 deg.C, 40-60wt.% of propylene content of the extract, 0.2-5.0g/dl of intrinsic viscosity of extracts in decalin at 140 deg.C, (B) ethylene-propylene based rubber of 40-60wt.% propylene content, (C) a triblock copolymer that has a 5-40g/10min MFR, 2000-10000 poise zero share viscosity at 23 deg.C, 30J/m<2> or more cortical energy release rate, in a quantity of 2-10wt.% based on (A) to (C) and (F), (D) a modified polyolefin polymer having hydroxyl group, in a quantity of 0.5-10 pts.wt. based on 100 pts.wt. of (A) to (C) and (F), (E) an oligomer having a terminal polar group, in a quantity of 0.5-10 pts.wt. based on 100 pts.wt. of (A) to (C) and (F), and (F) talc of 5μm or less particle size in a quantity of 0.5-10 pts.wt based on 100 pts.wt. of (A) to (C) and (F).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition which is excellent in impact resistance and paintability and does not generate flow marks. For example, the present invention relates to a resin composition suitable as a material for automobile bumpers and interior and exterior parts of automobiles. Things.

[0002]

2. Description of the Related Art As a technique for improving the impact resistance of materials for automobile bumpers and interior / exterior parts, propylene-based polymers such as propylene homopolymer, propylene-ethylene block copolymer, and propylene random copolymer have been used. Ethylene-propylene copolymers (JP-A-57-55952), ethylene-α-olefin copolymers (JP-A-4-372637, JP-A-5-331348, JP-A-6-192500), JP-A-6-192506) and blending of a hydrogenated product of a block copolymer of styrene and a diene (JP-A-7-53842) are reported.

[0003] In order to impart paintability to the above composition, a method of adding an EPR having an extremely low molecular weight is generally used. In addition, a method of adding a polyolefin modified with a compound having a polar group (JP-A-6-57838), particularly a method of adding a polyolefin modified with a compound having an unsaturated hydroxyl group (JP-A-5-39383) JP-A-3-157168, JP-A-5-117458, and JP-A-5-320442 have proposed a method of adding an oligomer having a polar group at the terminal.

[0004]

However, in the case of the materials formed by the above-mentioned methods, a large amount of extremely low molecular weight EPR or a chemically modified compound is added in order to develop sufficient solvent resistance of the coating film. And mechanical properties such as impact resistance tend to be greatly reduced. Even if a material having a good balance between paintability and impact resistance is obtained, a large molded product such as an automobile bumper has a drawback that a flow mark is easily generated and the product is defective.

[0005] The present invention has been made in order to solve such problems, and it is an object of the present invention to provide a propylene-based resin composition having excellent impact resistance and coating properties, and suppressing generation of flow marks. It is intended for.

[0006]

Means for Solving the Problems A propylene-based resin composition of the present invention made to solve the above-mentioned problems comprises: a component (A): a polypropylene-based polymer having a propylene-ethylene block copolymer; (B): an ethylene-propylene rubber; component (C): a triblock copolymer; component (D): a modified polyolefin polymer having a hydroxyl group; and component (E): an oligomer having a polar group at a terminal. Component (F): Polypropylene-based polymer containing talc and component (A) having a propylene-ethylene block copolymer has a melt flow rate measured at 230 ° C. under a load of 2.16 kg. Is 5
~ 100 g / 10 minutes, the ratio of xylene extractables at 20 ° C
15 to 60% by weight, the propylene content in the xylene extract component is 40 to 60% by weight, the intrinsic viscosity of the extract component in decalin at 140 ° C is 2.0 to 5.0 g / dl, and the component ( The ethylene-propylene rubber (B) has a propylene content of 40 to 60% by weight, and the triblock copolymer of the component (C) has a melt viscosity measured at 230 ° C under a load of 2.16 kg. The flow rate is 5 to 40 g / 10 min, and the viscosity at 230 ° C is constant in the region where the angular frequency is 1 rad / sec or less (called zero shear viscosity), and the zero shear viscosity is 2000 to 10,000 poise. A critical angle when the phase angle of the flat interface between the triblock copolymer and the xylene-insoluble component at 100 ° C. of the propylene-ethylene block copolymer of the component (A) is −2 ° to −12 °. Energy release rate is 30 J / m ² or more, and components (A), (B), (C)
And the ratio to the total of (F) is 2 to 10% by weight, and the modified polyolefin polymer having a hydroxyl group of the component (D) is 100 parts by weight of the components (A), (B), (C) and (F). Ratio 0.5 ~
10 parts by weight, and the proportion of the oligomer having a polar group at the terminal of the component (E) to 100 parts by weight of the components (A), (B), (C) and (F) is 0.5 to 10 parts by weight. The talc of F) has an average particle size of 5 μm or less, and the components (A), (B), (C) and
The ratio of (F) to the total is 5 to 25% by weight.

In this case, the component (C) is preferably a hydrogenated product of a styrene-butadiene-styrene triblock copolymer having a styrene content of 12 to 25% by weight. Further, it is preferable that the component (E) is a hydrogenated product of a butadiene oligomer having a hydroxyl group at a terminal.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Component (A): Polypropylene Polymer] The polypropylene polymer in the present invention needs to contain at least a propylene-ethylene block copolymer in its component. That is, the polypropylene-based polymer in the present invention may be the propylene-ethylene block copolymer alone,
In addition to ethylene block copolymer, random copolymer or propylene homopolymer (homopolypropylene)
Can be used in combination.

The comonomer of the random copolymer includes:
Ethylene, butene-1, hexene-1, octene-1,
Alpha-olefins other than propylene, such as 4-methylpentene-1, are preferred, and ethylene is particularly preferred.

In a block copolymer using ethylene as an α-olefin, that is, a propylene-ethylene block copolymer, an ethylene-propylene component in a molecule is dispersed in homopolypropylene, and the rubber component has a high impact resistance. Contributes to the development of sex.

The melt flow rate of the polypropylene polymer (according to JIS K7210 condition 14, hereinafter referred to as MFR) is preferably from 5 to 100 g / 10 minutes, more preferably from 15 to 50 g / 10 minutes. . If the MFR is less than 5 g / 10 minutes, the resulting resin composition has poor flowability, deteriorates moldability, and particularly generates flow marks. On the other hand, if the MFR exceeds 100 g / 10 minutes, there arises a problem that the impact resistance and coatability of the resin composition are reduced. The polypropylene-based polymer is obtained by melting and kneading a material having a low MFR (for example, MFR is 0.5 g / 10 min) in the presence of an organic peroxide (bisbreak), so that the MFR is within the above range. It can also be used.

It is preferable that the proportion of the xylene-extracting component at 20 ° C. in the polypropylene polymer is 15 to 60% by weight. More preferably, it is 25 to 50% by weight. This component corresponds to the rubber component. If the proportion of the xylene extractable component at 20 ° C. of the polypropylene-based polymer is less than 15% by weight, it is necessary to add a large amount of a rubber component in order to develop impact resistance. There are problems such as poor dispersion. On the other hand, if the content exceeds 60% by weight, there is a problem that cohesion tends to occur during the production of the polypropylene-based polymer, which is likely to cause trouble.

The propylene content in the xylene-extracted component of the polypropylene-based polymer at 20 ° C. is 40%.
Preferably it is 6060% by weight. More preferably, the content is 45 to 58% by weight. If the propylene content in the xylene extraction component is less than 40% by weight, there is a problem that the resulting resin composition does not exhibit impact resistance. On the other hand, if it exceeds 60% by weight, heat resistance and surface hardness are reduced.

Further, the intrinsic viscosity of the xylene-extracted component at 20 ° C. of the polypropylene polymer in decalin at 140 ° C. is preferably 2.0 to 5.0 g / dl. Furthermore, it is preferable that it is 2.0 to 3.5 g / dl. If the intrinsic viscosity of the component is less than 2.0 g / dl, the resulting resin composition does not exhibit impact resistance. On the other hand, if it exceeds 5.0 g / dl, not only is the coating property of the obtained resin composition inferior, but also there is a problem that poor dispersion is likely to occur and the impact resistance is lowered.

The ratio of this component (A) to the sum of components (A), (B), (C) and (F) of the polypropylene polymer is 55%
Preferably it is ~ 85% by weight. Further, the content is preferably 60 to 80% by weight. If the content ratio is less than 55% by weight, as a result, the amount of added rubber increases,
This leads to higher costs. On the other hand, if it exceeds 85% by weight, the coatability of the obtained resin composition tends to be poor.

[Component (B): Ethylene-propylene rubber] The ethylene-propylene rubber used in the present invention preferably has a propylene content of 40 to 60% by weight. If the propylene content is less than 40% by weight,
There is a problem that low-temperature impact resistance is not exhibited. on the other hand,
If it exceeds 60% by weight, heat resistance and surface hardness will decrease.

Further, the ethylene-propylene rubber may have
The MFR at 0 ° C. is preferably 0.5 to 10 g / 10 minutes. Further, 0.7 to 8 g / 10 minutes is preferable. MFR 0.5
If it is less than g / 10 minutes, poor dispersion is caused, the surface appearance of the molded article is deteriorated, and the mechanical performance is also reduced. On the other hand, if it exceeds 10 g / 10 minutes, impact resistance is hardly exhibited.

The ratio of the component (B) to the total of the components (A), (B), (C) and (F) of the ethylene-propylene rubber is preferably 5 to 20% by weight. If the content is less than 5% by weight, the impact resistance and the coating property are reduced. On the other hand, if it exceeds 20% by weight, the cost increases.

The ethylene-propylene rubber can be produced using a Ti catalyst, a V catalyst, and a metallocene catalyst.

[Component (C): Triblock copolymer] The triblock copolymer used in the present invention has the effect of improving the flow mark during molding. The MFR of the triblock copolymer measured at 230 ° C. under a load of 2.16 kg is preferably 5 to 40 g / 10 minutes. MFR is 5
If it is less than g / 10 minutes, the effect of improving the flow mark during molding is inferior. On the other hand, if it exceeds 40 g / 10 minutes, there is a problem that impact resistance, tensile elongation and the like are reduced.

The viscosity of the triblock copolymer at 230 ° C. becomes constant (called zero shear viscosity) in a region where the angular frequency is 1 rad / sec or less, and the zero shear viscosity at that time becomes 2000 to 10,000 poise. Preferably, there is. The viscosity at 230 ° C is not constant in the region where the angular frequency is less than 1 rad / sec, that is, the viscosity increases by 20% as the angular frequency decreases
If it increases above, the improvement effect of the flow mark is inferior,
There is a problem that paintability also deteriorates. Further, the zero shear viscosity at that time is preferably from 2000 to 10,000 poise. If the zero shear viscosity is less than 2000 poise, there is a problem that impact resistance, tensile elongation and the like are reduced.
On the other hand, if it exceeds 10,000 poise, there is a problem that the effect of improving the flow mark is inferior and the paintability is also deteriorated.

Further, 100% of the triblock copolymer and the propylene-ethylene block copolymer of the component (A)
Critical energy release rate when the phase angle of the flat interface with xylene-insoluble components at ℃ is -2 ° to -12 °
Called c. ) Is preferably 30 J / m ² or more. Gc
However, if it is less than 30 J / m ² , there is a problem that the resulting resin composition has reduced impact resistance and the like.

The ratio of this component (C) to the sum of components (A), (B), (C) and (F) of the triblock copolymer is 2 to 1
It is preferably 0% by weight. Furthermore, 2-5% by weight
Is preferred. If the content of the triblock copolymer in the resin composition is less than 2% by weight, there is a problem that the effect of improving the flow mark is small. On the other hand, if it exceeds 10% by weight, the resin composition becomes expensive, and there is a problem that the improvement of various physical properties cannot be expected for the cost.

The triblock copolymer is a hydrogenated product of a styrene-butadiene-styrene triblock copolymer (hereinafter referred to as SEBS) and has a styrene content of 12%.
Preferably it is 2525% by weight. In this case, if the content of styrene is less than 12% by weight, impact resistance and heat resistance decrease, and if it exceeds 25% by weight, the effect of improving the flow mark is small.

These triblock copolymers can be produced by a commonly used anion living polymerization method. This involves sequentially polymerizing styrene, butadiene, and styrene to produce a triblock copolymer, followed by hydrogenation, and first producing a styrene-butadiene diblock copolymer, followed by a coupling agent. And then hydrogenating the triblock copolymer using a butadiene,
There is a method in which styrene is sequentially polymerized and then hydrogenated. In either case, a diblock copolymer, a homopolymer, or the like is produced, but the content thereof must be less than 10% by weight of the entire triblock copolymer. If the content of the diblock copolymer or homopolymer exceeds 10% by weight, there is a problem that rigidity is reduced.

[Component (D): Modified Polyolefin Polymer Having a Hydroxyl Group] The modified polyolefin polymer having a hydroxyl group used in the present invention has an effect of improving coating properties. As the modified polyolefin polymer having a hydroxyl group, a polymer obtained by heating and reacting polyethylene, polypropylene, and an ethylene-α-olefin copolymer in the presence of an organic peroxide and an unsaturated compound having a hydroxyl group is preferable.

The organic peroxide used for the modified polyolefin polymer includes, for example, benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, dicumyl peroxide, α-α'-bis (t
-Butylperoxydiisopropyl) benzene, 2.5
-Dimethyl-2,5-di (t-butylperoxy) hexane, cumene hydroperoxide, t-butyl hydroperoxide and the like. The unsaturated compound having a hydroxyl group used in the modified polyolefin polymer includes:
Hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and the like are used.

The modified polyolefin polymer having a hydroxyl group of the component (D) has a blending amount of 0.5 to 10 parts by weight based on 100 parts by weight of the total of the components (A), (B), (C) and (F). The amount is preferred. If the content is less than 0.5 part by weight, more expensive additional rubber must be used in order to sufficiently exhibit paintability, resulting in an increase in cost. On the other hand, if it exceeds 10 parts by weight, there is a problem that impact resistance, rigidity and the like are reduced.

[Component (E): Oligomer Having Polar Group at Terminal] The oligomer having a polar group at the terminal used in the present invention has an effect of improving coating properties. The oligomer having a polar group at the terminal is a liquid rubber or wax-like solid, and is an oligomer having at least one functional group at one terminal in one molecule. Here, the functional group includes a hydroxyl group, an amino group, a carboxyl group, an epoxy group, a thiol group, a maleic anhydride group, and the like, and may include these two or more kinds as long as they do not react with each other.

The number average molecular weight of the oligomer is from 300 to 10,000
Is preferable, but 500 to 8000 is more preferable. More preferably, it is 500 to 6000. If the number average molecular weight is less than 300, rigidity and impact resistance are reduced, which is not preferable. On the other hand, if it exceeds 10,000, the paintability deteriorates.

Specific examples of the oligomer include polybutadiene, polyisoprene, isobutylene-isoprene copolymer (butyl rubber), polybutene, butadiene-
An acrylonitrile copolymer, a petroleum resin, or a partially or completely hydrogenated product thereof is an oligomer having at least one terminal functional group in one molecule.

These oligomers can be produced by a known method. For example, commercially available products include hydroxy-terminated hydrogenated 1,4-polybutadiene (trade name: Polytail H, Polytail HA, manufactured by Mitsubishi Chemical Corporation), and hydroxy-terminated hydrogenated polyolefin (trade names: Epol, Idemitsu) Petrochemical Co., Ltd.), hydroxy-terminated 1,2-polybutadiene (product name: NISSO-PB G-1)
000, NISSO-PB GI-1000, manufactured by Nippon Soda Co., Ltd.), amino-terminal acrylonitrile-butadiene rubber (trade name: Hy)
Car-ATBN, manufactured by Ube Industries, Ltd.), amino group-terminated polyethylene glycol (trade name: Jeffamine, manufactured by Texaco Chemical) and the like are easily available and can be suitably used.

The oligomer of the component (E) is
(A), (B), (C) and (F) as a total of 100 weight, 0.5 to 10
It is preferable to mix parts by weight. If the content is less than 0.5 part by weight, no paintability is exhibited. On the other hand, if it exceeds 10 parts by weight, the rigidity is reduced, which is not preferable.

[Component (F): Talc] The average particle size of talc used in the present invention is preferably 5 μm or less.
If the average particle size exceeds 5 μm, there is a problem that impact resistance, tensile elongation and the like are reduced. The talc of this component (F) has a ratio of the total of components (A), (B), (C) and (F)
5 to 25% by weight. If it is out of this range, it is difficult to satisfy the elastic modulus, impact resistance, and the like suitable for automotive materials.

[Gc measurement method] In the present invention, Gc is a critical energy release rate of cracks existing at a flat interface between a triblock copolymer and a xylene-insoluble component of a propylene-ethylene block copolymer at 100 ° C. Is defined by To measure Gc, the asymmetric double cantilever beam method (hereinafter referred to as ADCB method; see: Costantino Creton, dissertation, Cornell University, 1992
Year). This is to allow cracks to grow along the interface. Conventional peel tests do not allow cracks to grow along the interface. As a result, the cracks penetrate into the softer material (that is, into the triblock copolymer), and
Gc cannot be measured accurately.

The parameter that determines the crack growth direction is a phase angle Ψ defined by the following equation. Ψ = tan ⁻¹ (K _II / K _I ) Here, K _I and K _II are stress intensity factors corresponding to mode I (tensile) and mode II (in-plane shear), respectively. Ψ depends on the geometry of the ADCB method, the elastic modulus of each material, Poisson's ratio, and crack length. Actually, evaluation is made by the boundary element method (BEM method) and the finite element method (FEM method).

In the present invention, it is necessary to measure Gc when Ψ is in the range of −2 ° to −12 °. Here, when the crack proceeds in the direction of the thin beam, Ψ is defined to be negative.
If Ψ is smaller than -12 °, cracks at the interface penetrate into a thin beam, and there is a problem that Gc at the interface cannot be measured accurately. On the other hand, if Ψ is −2 ° to 0 °, the crack growth at the interface is unstable, and there is a problem that the Gc at the interface cannot be measured accurately as before. Further, if Ψ exceeds 0 °, cracks enter the triblock copolymer, and there is a problem that Gc at the interface cannot be measured accurately.

In producing the resin composition of the present invention,
Uses additives such as heat, oxygen and light stabilizers, flame retardants, fillers, colorants, lubricants, plasticizers, and antistatic agents that are widely used in the synthetic resin and synthetic rubber fields. May be added within a range that does not essentially impair the properties of the resin composition of the present invention.

For example, the following are mentioned as antioxidants. Dibutylhydroxytoluene, alkylated phenol, 4,4'-thiobis- (6-t-butyl-
3-methylphenol), 4,4'-butylidenebis-
(6-t-butyl-3-methylphenol), 2,2'-
Methylenebis- (4-methyl-6-t-butylphenol), 2,2'-methylenebis- (4-ethyl-6-t-
Butylphenol), 2,6-di-t-4-ethylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane, n-octadecyl-3- ( 4-hydroxy-3,5-di-t-butylphenyl) propionate, tetrakis [methylene-3-
(3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, dilaurylthiodipropionate, distearylthiodipropionate, dimyristylthiothiopionate. Hindered phenol compounds include triethylene glycol-bis [3-
(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2 , 4-Bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, pentaerythryl-tetrakis [3- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3
-(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], N, N'-hexamethylenebis (3.5
-Di-tert-butyl-4-hydroxy-hydrocinnamamide), 3,5-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6- Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-t
-Butyl-4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl] -o-cresol. In addition, hydrazine compounds include N, N'-bis [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionyl] hydrazine. In addition, a phenolic antioxidant, a phosphite antioxidant, a thioether antioxidant, a heavy metal deactivator and the like can be applied.

As the ultraviolet absorber, for example, 2-
(2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-
5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2-hydroxy-4-n-oct Xybenzophenone, phenyl salicylate, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,
5-bis (α, α-dimethylbenzyl) phenyl] -2H
-Benzotriazole, 2- (3,5-di-t-butyl-
2-hydroxyphenyl) benzotriazole, 2-
(3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-
Di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-
2-hydroxyphenyl) benzotriazole, 2-
(2′-hydroxy-5′-t-octylphenyl) benzotriazole, hydroxyphenylbenzotriazole derivatives and the like. Or dimethyl succinate-1-
(2-hydroxyethyl) -4-hydroxy-2,2,
6,6-tetramethylpiperidine polycondensate, poly {[6
-(1,1,3,3, -tetramethylbutyl) amino-1,
3,5-Triazine-2,4-diyl] [(2,2,6,6
-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]}, N, N'-bis (3-aminopropyl) ethylenediamine.2.4 -Bis [N-butyl-N- (1,
2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, Bis (1,2,2,2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate
6,6-pentamethyl-4-piperidyl), 2,4-di-
t-butylphenyl-3,5-butyl-4-hydroxybenzoate and the like.

As the flame retardant, for example, the following can be applied. Polybromodiphenyl oxide, tetrabromobisphenol A, brominated epoxy hexabromocyclododecane, ethylene bistetrabromophthalimide, brominated polystyrene dechlorane, brominated polycarbonate, polyphosphonate compound, halogenated polyphosphonate, triazine, red phosphorus, Tricresyl phosphate, triphenyl phosphate, crediphenyl phosphate, triallyl phosphate, trixylyl phosphate, trialkyl phosphate, trischloroethyl phosphate, trischloropropyl phosphate, tris (dichloropropyl phosphate), antimony trioxide, aluminum hydroxide, water An example is magnesium oxide. Further, silicone oil, stearic acid, calcium stearate, barium stearate, aluminum stearate, zinc stearate, magnesium stearate, carbon black, titanium dioxide, silica, mica, montmorillonite and the like may be added.

In addition to these additives, inorganic fillers may be added. Examples of the inorganic filler include fibrous materials such as barium titanate whiskers, calcium carbonate whiskers, magnesium sulfate whiskers, boron-based whiskers, carbon fibers and glass fibers, and particulate materials such as calcium carbonate and magnesium carbonate.

[Production Method] The resin composition of the present invention is produced by uniformly mixing the above-mentioned components, additives and the like. There is no particular limitation on the mixing method, and a method generally used in the field of synthetic resins may be applied. As a mixing method, a method of dry blending using a commonly used mixer such as a Henschel mixer, a tumbler, and a ribbon mixer, and a mixer such as an open roll, an extrusion mixer, a kneader, and a Banbury are used. And mixing while melting.

Of these methods, in order to obtain a more uniform resin composition, two or more of these mixing methods may be used in combination. For example, after dry-blending in advance, the mixture is melt-mixed. Even when dry blending is used in combination, or when one or two or more types of melt-mixing methods are used in combination, a pelletized product must be produced using a pelletizer before producing a molded product by a molding method described below. Is particularly preferred.

Of the above-mentioned mixing methods, either in the case of melting and mixing, or in the case of molding by a molding method described later,
It must be carried out at a temperature at which the resin used melts. However, when carried out at a high temperature, the resin is thermally decomposed and degraded.
Performed at ~ 260 ° C.

The resin composition of the present invention may be formed into a desired shape by using an injection molding method, an extrusion molding method, a compression molding method, a hollow molding method, etc., which are generally performed in the field of synthetic resins. Alternatively, after forming into a sheet using an extruder, the sheet may be formed into a desired shape by a secondary processing method such as a vacuum forming method or a pressure forming method.

[0047]

The present invention will be described below in detail with reference to examples. Table 1
(A) propylene-ethylene block copolymer, (B) ethylene-propylene rubber, (C) triblock copolymer, (F) talc, and the following (D) hydroxyl-modified polyolefin polymer shown in Various propylene-based resin compositions were produced using the combined and (E) oligomers having a polar group at the terminal.

In Tables 1 and 3, the MFR (g / 10 min) was measured according to JIS K7210 condition 14 under the condition of a load of 2.16 kg at 230 ° C. In Table 1, the value of the propylene content in the xylene-extracted component at 20 ° C. measured by NMR is Fp (% by weight), and the amount of xylene extracted from the propylene-ethylene block copolymer (A) is CE / P (% by weight). ), The intrinsic viscosity of the xylene-extracted component in decalin at 140 ° C. is [η] E /
P (dl / g).

[0049]

[Table 1]

[0050]

[Table 2] Fp (% by weight) in Table 2 is the propylene content measured by NMR.

[0051]

[Table 3] In Table 3, the types of triblock copolymers are as follows: styrene-butadiene-styrene triblock copolymer hydrogenated product is SEBS; styrene-isoprene-styrene triblock copolymer hydrogenated product is SEPS; The hydrogenated product of -butadiene-1,2-butadiene-1,4-butadiene block copolymer was abbreviated as CEBC. The zero shear viscosity (η.) At 230 ° C. of these triblock copolymers was determined to have an angular frequency (ω) of 0.1 by Rheometrics RSAII.
It was measured in the region of 1010 rad / sec and determined by extrapolating to ω = 0. The unit is poise. The critical energy release rate (Gc) of the flat interface between the triblock copolymer shown in Table 3 and the (A) xylene-insoluble component of the propylene-ethylene block copolymer at 100 ° C.
(J / m ² )) are disclosed in JP-A-7-286088 and JP-A-7-292175.
It measured by the asymmetric double cantilever beam method of Unexamined-Japanese-Patent Publication. That is, a triblock copolymer,
(A) A xylene-insoluble component at 100 ° C. of a propylene-ethylene block copolymer is press-molded to form a sheet having a thickness of about 1 mm.
C. for 10 minutes with a press molding machine. Thereafter, a crack was formed in the interface with a razor blade having a thickness of 0.25 mm, and the critical energy release rate was measured by the ADCB method. At this time, the thickness ratio of both beams was calculated and set by the boundary element method so that Ψ became −7 °.

(D) Modified Polyolefin Polymer Having a Hydroxyl Group Component (D) The modified polyolefin polymer having a hydroxyl group is composed of 100 parts by weight of homopropylene having an MFR of 0.5 g / 10 min.
After 4 parts by weight of hydroxyethyl methacrylate and 1 part by weight of 2,5-bis (t-butylperoxy) -2,5-dimethylhexane were dry-blended with a Henschel mixer,
The mixture was kneaded and denatured at 180 ° C. using a 20 mm co-rotating twin screw extruder. The hydroxyl content of the resulting modified polypropylene,
It was 0.09 mmol / g as measured by infrared spectroscopy, and the weight average molecular weight was 110,000 as measured by GPC (gel permeation chromatography).

(E) Oligomers Having a Polar Group at the Terminal Component The oligomers having a polar group at the terminal (E) include waxy hydrogenated terminal hydroxylated 1,4-polybutadiene (1,4-bond 80%, number average (Molecular weight 2800, iodine value 1.5, average number of hydroxyl groups 2.3 / molecule, melting point 72.5 ° C) were used.

[0054]

[Table 4] The particle size of the component (F) talc was measured using a laser sedimentation method.

The above components (A) to (F) were blended according to the formulation shown in Table 5. In addition, about the modified polyolefin polymer which has a hydroxyl group of a component (D), Examples 1-6 and Comparative Example 1
-9 and Comparative Examples 11, 13, and 14 only 5.0 parts by weight were added. As for the oligomer having a polar group at the terminal of the component (E), 2.0 parts by weight were added only to Examples 1 to 6, Comparative Examples 1 to 9, and Comparative Examples 12 to 14.
The kneading was performed by dry blending for 3 minutes using a Henschel mixer, and then pellets of the resin composition were produced using a co-directional twin screw extruder (diameter 30 mm) set at 210 ° C. The obtained pellets of each resin composition were molded using an injection molding machine set at 210 ° C. to prepare test pieces for measuring various physical properties.

[0056]

[Table 5]

Each physical property in Table 5 is based on the following test. (1) Low Temperature Impact Test (IZOD) Izod impact strength was measured with a notch at a temperature of -30 ° C. according to ASTM D265. The unit is (J / m).

(2) Flow Mark Test A flat plate of 80 mm × 240 mm × 3 mm was formed, and the appearance of the flow mark was visually observed and evaluated. ○ indicates no flow mark, △ indicates slight flow mark,
X indicates that a flow mark is remarkably generated.

(3) Paintability test The paintability was determined by washing and drying the previously molded flat plate with ion-exchanged water. Thereafter, a two-part urethane paint was directly applied at 30 μm without using a primer, and baked at 80 ° C. for 30 minutes. A strip of the coated sample was immersed in a gasoline / ethanol mixture (90/10% by volume) at 20 ° C. so that the cross section appeared equally, and the time (minute) until the coating film was peeled was measured.

From the results shown in Table 5, all of the resin compositions of Examples 1 to 6 were able to obtain molded articles excellent in low-temperature impact resistance, flow mark properties, and coatability.
However, in Comparative Example 1 in which the component (A) having a large intrinsic viscosity was blended, many flow marks were generated, and in Comparative Example 2 in which the component (A) having a small intrinsic viscosity was blended, the impact resistance was low. Comparative Example 3, in which the component (A) having a low propylene content is blended, has low impact resistance and generates a flow mark. Further, Comparative Example 4 in which the component (B) having a low propylene content is blended has low impact resistance, and Comparative Example 5 in which the blending amount of the component (C) is small has many flow marks. Further, in Comparative Examples 6 to 8 in which the component (C) having a large or no zero shear viscosity was blended, many flow marks were generated, and in Comparative Example 9 in which talc having a large average particle size was used, the impact resistance was low. ,
Comparative Example 1 not containing component (D) or component (E)
Nos. 0 to 12 have excellent impact resistance and do not have flow marks, but have poorer coatability than those of Examples 1 to 4.

[0061]

According to the present invention, a resin composition having excellent low-temperature impact resistance, flow mark properties and paintability can be provided, and can be used in a wide range of fields such as automobile interiors, bumpers and home appliances.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 23/26 LDA C08L 23/26 LDA 47/00 LKJ 47/00 LKJ (72) Inventor Kunio Yamamoto Kawasaki Laboratory, Kawasaki-ku, Kanagawa Prefecture, Japan 2-3-2 Kawasaki Research Laboratory, Japan Polyolefin Co., Ltd. (72) Inventor Hideo Yamamoto 2-3-2, Yakko, Kawasaki-ku, Kawasaki City, Kanagawa Japan Kawasaki Laboratory, Polyolefin Corporation 72) Inventor Kunihiko Asai 2-3-2 Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Kawasaki Laboratory, Japan Polyolefin Co., Ltd.

Claims (3)

[Claims] 1. A component (A): a polypropylene polymer having a propylene-ethylene block copolymer, a component (B): an ethylene-propylene rubber, and a component (C): a triblock copolymer. Component (D): a modified polyolefin polymer having a hydroxyl group, component (E): an oligomer having a polar group at a terminal, and component (F): talc, component (A) a propylene-ethylene block copolymer Has a melt flow rate of 5 to 1 measured at 230 ° C under a load of 2.16 kg.
00 g / 10 minutes, the ratio of the xylene extraction component at 20 ° C. is 15
-60% by weight, the propylene content in the xylene extracted component is 40-60% by weight, and the intrinsic viscosity of the extracted component in decalin at 140 ° C. is 2.0-5.0 g / dl, and the component (B ) The ethylene-propylene rubber has a propylene content of 40 to 60% by weight, and the component (C) triblock copolymer has a melt flow rate measured under the condition of a load of 2.16 kg at 230 ° C. Five
4040 g / 10 min, at 230 ° C., the viscosity becomes a constant zero shear viscosity in the region where the angular frequency is 1 rad / sec or less, the zero shear viscosity is 2000 to 10,000 poise, and the triblock copolymer and the component The critical energy release rate is 30 J / m ² or more when the phase angle of the flat interface between the propylene-ethylene block copolymer (A) and the xylene-insoluble component at 100 ° C is -2 ° to -12 °. And the components (A), (B), and (C)
And (F) in a proportion of 2 to 10% by weight based on the total weight of the components (D) and 100% by weight of the modified polyolefin polymer having a hydroxyl group with respect to components (A), (B), (C) and (F). Is 0.5
To 10 parts by weight, Component (E) Component (A) of an oligomer having a polar group at the terminal,
(B), (C) and (F) 100 parts by weight of 0.5 to 10 parts by weight, the component (F) talc has an average particle size of 5 μm or less,
The proportion of the total of the components (A), (B), (C) and (F) is 5 to 25.
% By weight of the propylene-based resin composition. 2. The component (C) is a hydrogenated styrene-butadiene-styrene triblock copolymer,
2. The propylene resin composition according to claim 1, wherein the styrene content is 12 to 25% by weight. 3. The propylene resin composition according to claim 1, wherein the component (E) is a hydrogenated butadiene oligomer having a hydroxyl group at a terminal.