JPH10101891A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition having high impact resistance and good application property of paint and causing no drop of the impact strength after coating. SOLUTION: This composition comprises (A) a polypropylene-based polymer having propylene-ethylene block copolymer, (B) an ethylene-octene-based rubber, (C) a triblock copolymer, (D) a modified polyolefin polymer having a hydroxy group and (E) talc. The component A has 5-100g/10min melt flow rate(MFR) at 230 deg.C under 2.16kg load and the xylene extract of the component A at 20 deg.C has 2.0-5.0g/dl intrinsic viscosity in 140 deg.C decalin. The component B has 0.5-200g/10min MFR and 15-35wt.% octene content. The component C has 20-200g/10min MFR. The critical energy release rate between the component C and the xylene-undissolved component of the component Aat 100 deg.C is >=20J/m<2> . The content of the unsaturated compound having a hydroxy group in the component D is 0.5-7wt.%. The component E has <=5μm average particle diameter. The percentage of component C is 2-10wt.% and that of component E is 5-25wt.% based on the total of components (A), (B), (C) and (E). The component D of 0.5-20 pts.wt. based on the total of the components (A), (B), (C) and (E) of 100 pts.wt. is added thereto.

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 reduce impact strength after painting. For example, a resin composition suitable as a material for automobile bumpers, automobile interior and exterior parts, and the like. It relates to a composition.

[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 copolymer (JP-B-60-3420), ethylene-α-olefin copolymer (JP-A-4-372637,
JP-A-5-331348, JP-A-6-192500, JP-A-Hei.
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 order to exhibit sufficient paintability, it is necessary to add a large amount of an extremely low molecular weight EPR or a chemically modified compound in the material formed by the above method. In addition, mechanical properties such as impact resistance tend to be greatly reduced. In particular, D after painting
There is a disadvantage that uPont impact strength is reduced.

[0005] The present invention has been made to solve such a problem, and provides a resin composition having excellent impact resistance and paintability, and having a reduced DuPont impact strength after coating. It is intended to do so.

[0006]

The resin composition of the present invention comprises:
Component (A) a polypropylene-based polymer having a propylene-ethylene block copolymer, and component (B) ethylene-
An octene rubber, a component (C) a triblock copolymer, a component (D) a modified polyolefin polymer having a hydroxyl group, and a component (E) talc, and a propylene-ethylene block of the component (A) The polypropylene polymer with the copolymer has a load of 2.16 kg at 230 ° C.
The melt flow rate measured under the conditions described above is 5-100 g / 10 minutes, the intrinsic viscosity of the xylene extract at 20 ° C. in decalin at 140 ° C. is 2.0-5.0 g / dl, and the component (B The ethylene-octene rubber of the above) has an octene content of 15-35% by weight, a melt flow rate measured at 230 ° C under a load of 2.16 kg of 0.5-10 g / 10 min, and a component (C The triblock copolymer has a melt flow rate of not less than 20 g / 10 min and not more than 200 g / 10 min measured at 230 ° C. under a load of 2.16 kg. A) The flatness between the propylene-ethylene block copolymer and the xylene-insoluble component at 100 ° C
Energy release rate is 20 J / m ² or more when the phase angle of the interface is −2 ° to −12 °, and the component (A), component (B),
Component (C) in total weight of component (C) and component (E)
Is 2-10% by weight, the content of the hydroxyl-containing unsaturated compound in the hydroxyl-modified polyolefin polymer of the component (D) is 0.5-7% by weight, and the component (D) is the component (D). 0.5-20 parts by weight is added to the total of 100 parts by weight of (A), component (B), component (C) and component (E), and talc of component (E) has an average particle size of 5 μm or less. And component (A), component (B), component (C) and component (E)
Component (E) accounts for 5-25% by weight of the total weight of
It is characterized by being. In this case, the component (C) is a hydrogenated product of a styrene-butadiene-styrene triblock copolymer, and the styrene content is 12-3.
Preferably it is 5% by weight. The component (C) is a hydrogenated product of a styrene-isoprene-styrene triblock copolymer, and the styrene content is 12 to 35% by weight.
It is preferred that

[0007]

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. This polypropylene-based polymer is
The propylene-ethylene block copolymer alone may be used, but in addition to the propylene-ethylene block copolymer, a random copolymer or a propylene homopolymer (homopolypropylene) may be used in combination. it can.

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 the block copolymer using ethylene as the α-olefin, that is, in the propylene-ethylene block copolymer, the ethylene-propylene component in the molecule is dispersed in homopolypropylene, and the rubber component has impact resistance. Contributes to expression.

[0009] The melt flow rate (according to JIS K7210 condition 14, hereinafter referred to as MFR) of the polypropylene polymer is preferably 5 to 100 g / 10 minutes, and more preferably 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,
A material having a low MFR (for example, an MFR of 0.5 g / 10 min) is melt-kneaded (visbreaked) in the presence of an organic peroxide, so that a material having an MFR within the above range can be used.

It is preferable that the proportion of the xylene extractable component at 20 ° C. in the polypropylene polymer is 15 to 60% by weight. More preferably, it is 25-50% by weight. This component corresponds to the rubber component. The proportion of the xylene extractable component at 20 ° C. of the polypropylene polymer is
If the amount is less than 15% by weight, a large amount of a rubber component must be additionally added in order to develop impact resistance, so that there are problems such as an increase in cost and 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 polymer at 20 ° C. is 40%.
Preferably it is -60% by weight. 45-58% by weight
It is preferred that 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 polypropylene-based polymer is heated at 20 ° C.
The intrinsic viscosity of the xylene-extracted component in decalin at 140 ° C. is preferably 2.0-5.0 g / dl. Further, it is preferably 2.0-3.5 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.

Further, in the resin composition of the present invention, the content of the component (A) in the total weight of the component (A), the component (B), the component (C) and the component (E): the content of the polypropylene polymer Is preferably 55 to 85% by weight. Further, the content is preferably 60 to 80% by weight. Content is 55
If the content is less than% by weight, as a result, the amount of added rubber increases, leading to an increase in cost. On the other hand, if it exceeds 85% by weight, the coatability of the obtained resin composition tends to be poor.

[Component (B): ethylene-octene rubber] The octene content of the ethylene-octene rubber used in the present invention is preferably 15 to 35% by weight. When the octene content is less than 15% by weight, there is a problem that low-temperature impact resistance is not exhibited. On the other hand, if it exceeds 35% by weight, heat resistance and surface hardness are reduced.

Further, the ethylene-octene rubber may contain 230
Preferably, the MFR at 0 C is 0.5-10 g / 10 minutes.
Further, 0.7-8 g / 10 minutes is preferable. MFR 0.5 g / 10
If it is less than minutes, poor dispersion occurs, the surface appearance of the molded article deteriorates, and the mechanical performance also decreases. on the other hand,
If it exceeds 10 g / 10 minutes, there is a problem that impact resistance is not exhibited. Further, when the molded product is taken out, there is a problem that the surface of the molded product is peeled off.

Component (B) based on the total weight of component (A), component (B), component (C) and component (E):
The octene rubber content is preferably 5-40% by weight. If the content is less than 5% by weight, impact resistance,
And the paintability decreases. On the other hand, if it exceeds 40% by weight, the cost increases. The ethylene-octene 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 DuPont impact strength after coating. The MFR of the triblock copolymer measured at 230 ° C. under a load of 2.16 kg is preferably 20 g / 10 min or more and 200 g / 10 min or less. Further, the MFR is preferably 25 g / 10 min or more and 180 g / 10 min or less. If the MFR is less than 20 g / 10 minutes, the decrease in DuPont impact strength after coating is severe. On the other hand, if it exceeds 200 g / 10 minutes, there is a problem that impact resistance, tensile elongation and the like are reduced.

Further, the viscosity of the triblock copolymer at 230 ° C. becomes constant in a region where the angular frequency is 1 rad / sec or less (referred to as zero shear viscosity), and the zero shear viscosity at that time is 2000-10000 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 2000-10000 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, the triblock copolymer and (A)
The phase angle of the flat interface between the propylene-ethylene block copolymer and the xylene-insoluble component at 100 ° C. is −2 °.
It is preferable that the critical energy release rate (hereinafter referred to as Gc) at −12 ° is 20 J / m ² or more. Gc is 20
If it is less than J / m ² , there is a problem that impact resistance and the like of the obtained resin composition are reduced.

Further, component (A), component (B), component (C)
Component (C) based on the total weight of component (E) and component (C): the content of the triblock copolymer is preferably 2 to 10% by weight. Further, 2-5% by weight is preferable. The content of the triblock copolymer in the resin composition is,
If it is less than 2% by weight, there is a problem that the decrease in DuPont impact strength after coating is large. On the other hand, if it exceeds 10% by weight, the resin composition becomes expensive, and there is a problem that improvement of various physical properties cannot be expected for the cost.

Further, the triblock copolymer is a hydrogenated product of a styrene-butadiene-styrene triblock copolymer (hereinafter referred to as SEBS), and preferably has a styrene content of 12 to 35% by weight. . In this case, if the styrene content is less than 12% by weight, there is a problem that impact resistance and heat resistance are reduced. On the other hand, if it exceeds 35% by weight, there is a problem that impact resistance is reduced.
Further, the triblock copolymer is a hydrogenated product of a styrene-isoprene-styrene triblock copolymer (hereinafter, referred to as SEPS), and preferably has a styrene content of 12 to 35% by weight. In this case, if the styrene content is less than 12% by weight, there is a problem that impact resistance and heat resistance are reduced. On the other hand, if it exceeds 35% by weight, there is a problem that impact resistance is reduced.

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 comprises polyethylene, polypropylene, an ethylene-α-olefin copolymer, and an organic peroxide. Those obtained by heating and reacting in the presence of an unsaturated compound having a hydroxyl group are preferred. Examples of the unsaturated compound having a hydroxyl group include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.

In the resin composition of the present invention, the component (D): the modified polyolefin polymer having a hydroxyl group comprises:
It is preferable to add 0.5-20 parts by weight to the total of 100 parts by weight of the components (A), (B), (C) and (E). 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 20 parts by weight, there is a problem that impact resistance, rigidity and the like are reduced. The content of the unsaturated compound having a hydroxyl group in the modified polyolefin polymer having a hydroxyl group of the component (D) is preferably 0.5 to 7% by weight. 0.8-2
% By weight. If the content of the hydroxyl group-containing unsaturated compound in the hydroxyl group-modified polyolefin polymer of the component (D) is less than 0.5% by weight, the paintability is poor. If it exceeds 7% by weight, rigidity and impact resistance are reduced.

[Component (E): 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. In the resin composition of the present invention, the content of component (E): talc in the total weight of component (A), component (B), component (C) and component (E) is 5 to 25% by weight. Desirably. 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 the critical energy release of cracks existing at the flat interface between the triblock copolymer and the xylene-insoluble component at 100 ° C in the propylene-ethylene block copolymer. Defined by rate. To measure Gc, the asymmetric double cantilever beam method (hereinafter referred to as the ADCB method; see: Costantino Creton, Dissertation, Cornell University, 1992)
Year). This is to allow cracks to grow along the interface. In the conventional peel test, cracks could not be grown along the interface. For this reason, the crack penetrated into the softer material (that is, in the ethylene-octene rubber or the triblock copolymer), and the Gc at the interface could not be measured accurately.

A 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 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-butyl-
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, Dimyristylylthiopropionate. Hindered phenol-based 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-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3,5-t-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-butyl-4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl] -o -Ku
There is a resole. Hydrazines 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-octoxybenzophenone,
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-t-butyl-2-hydroxyphenyl)
-5-chlorobenzotriazole, 2- (3,5-di-
There are t-amyl-2-hydroxyphenyl) benzotriazole, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, hydroxyphenylbenzotriazole derivatives and the like. Also, 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, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid Bis (1,2,2,6,6-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, ethylenebistetrabromophthalimide, 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 mixing methods, whether melt-mixing or molding by the molding method described below,
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 practiced in the field of synthetic resins. Further, after the sheet is formed into a sheet shape 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.

[0038]

The present invention will be described below in detail with reference to examples. [Preparation of Resin Composition] A propylene-ethylene block copolymer shown in Table 1 as a component (A), an ethylene-octene rubber shown in Table 2 as a component (B), and a triene shown in Table 3 as a component (C). Using a block copolymer, a modified polyolefin polymer having a hydroxyl group shown in Table 4 as a component (D), and talc shown in Table 5 as a component (E),
A resin composition was manufactured.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

[Table 5]

In Tables 1 to 4, MFR is JIS K7210 condition 14 (g / 10
Min). In Table 1, the propylene content (% by weight) measured by NMR is Fp, and the xylene extraction amount of the (A) propylene-ethylene block copolymer is CE / P
(% By weight) and the intrinsic viscosity of the xylene-extracted component is [η] E /
It was indicated by P (dl / g). In Table 2, the octene content (% by weight) measured by NMR is indicated by Fo. In Table 3, the types of triblock copolymers are abbreviated as SEBS for hydrogenated styrene-butadiene-styrene triblock copolymers and as SEPS for hydrogenated styrene-isoprene-styrene triblock copolymers. The styrene content (% by weight) measured by NMR was indicated by Fs.

Component (D) The modified polyolefin polymer having a hydroxyl group has 100 parts by weight of homopropylene having an MFR of 0.5 g / 10 min, 3 parts by weight of 2-hydroxyethyl methacrylate (referred to as HEMA), and 2,5- Screw (t
-Butylperoxy-isopropyl) benzene (1 part by weight) was dry blended with a Henschel mixer, and then 20 mm
The mixture was kneaded and denatured at 180 ° C. using a co-rotating twin screw extruder. The hydroxyl content of the resulting modified polypropylene was 0.09 mmol / g as measured by infrared spectroscopy, and the weight-average molecular weight was 110 as measured by GPC.
000. Similarly, a copolymer prepared by replacing the monomer to be copolymerized with hydroxybutyl acrylate (HBA) was used. Furthermore, using HEMA, the thing which changed the copolymerization amount was manufactured. These are abbreviated as UK and are summarized in Table 4. In Table 5, the particle size of talc was measured using a laser sedimentation method.

Each of the components shown in Tables 1 to 5 was blended according to the formulation shown in Table 6, dry-blended for 3 minutes using a Henschel mixer, and then coaxially twin-screw extruder (diameter 30 mm) set at 210 ° C. To produce pellets of the resin compositions of Examples 1 to 7 and Comparative Examples 1 to 17. In addition,
In Table 6, for convenience, the type of each component used and the content thereof are shown in% by weight based on the entire resin composition. Here, the critical energy release rate (Gc) of the flat interface between the (C) triblock copolymer used in each resin composition and the (A) xylene-insoluble component of the propylene-ethylene block copolymer at 100 ° C. (J / m ² )) is shown in Table 7. The critical energy release rate (Gc (J / m ² )) is described in JP-A-7-286088.
And the asymmetric double cantilever beam method described in JP-A-7-292175. That is, the xylene-insoluble components at 100 ° C. of the triblock copolymer and the propylene-ethylene block copolymer are each press-molded to form a sheet having a thickness of about 1 mm, and they are superimposed and pressed at 200 ° C. for 10 minutes. It was thermocompression bonded with a 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 °.

[Physical Properties Test] Examples 1 to 7 and Comparative Example 1
The pellets of each of the resin compositions Nos. To 17 were molded using an injection molding machine set at 210 ° C. to prepare a test piece (130 mm × 130 mm × 3 mm flat plate) for measuring the DuPont impact strength. Each piece was subjected to each physical property test according to the method described below. The results are shown in Table 7.

(1) High-Pressure Coating Resistance Test First, the test piece (130 mm × 130 mm × 3 mm flat plate) formed by injection molding was washed with ion-exchanged water and dried. Then, a masking tape (130 mm in length and 35 mm in width) was attached to the center of the flat plate. After that, apply a chlorinated polypropylene primer from above to a film thickness of 10 μm, and
After drying for 30 minutes, a two-part urethane paint was applied to a film thickness of 30 μm and baked at 80 ° C. for 30 minutes. Then, the masking tape was peeled off, and as shown in FIG.
A painted surface 11 and a non-painted surface 12 where the masking tape was peeled off were formed thereon. Then, as shown in FIG. 2, toward the boundary between the non-painted surface 12 and one painted surface 11,
Water was sprayed from a fountain tube (diameter: 1.5 mm) 13 for 5 minutes (pressure = 50 kg / cm ² ). The fountain tube 13 and the upper surface of the test piece were arranged at an angle of 30 ° and a distance of 20 cm. After the spraying was completed, as shown in FIG. 3, the length from the boundary of the portion where the coating film was peeled was measured, and the longest distance was defined as the amount of peeling. The unit is mm.

(2) DuPont Impact Strength Test A test piece for measuring DuPont impact strength (13
0mm x 130mm x 3mm flat plate) was prepared, and the impact strength before painting and the impact strength after painting were measured at -30 ° C.
In accordance with ASTM D3029. The unit is kgf · cm. The coating was performed by applying a chlorinated polypropylene-based primer from above to a thickness of 10 μm, drying at 80 ° C. for 30 minutes, and then applying a two-part urethane paint to a thickness of 30 μm.
Performed by baking at 30 ° C. for 30 minutes. (3) Flexural modulus The flexural modulus (FM) was measured using the above-mentioned injection molded test piece.
Measured at 23 ° C. according to ASTM D790. The speed of the crosshead at this time was 30 mm / min. The unit is kgf / cm ² . (4) Izod Impact Strength The notched test pieces were measured at −30 ° C. according to ASTM D256 using the injection molded test pieces.

[0050]

[Table 6]

[0051]

[Table 7]

From the results shown in Table 7, all of the resin compositions of Examples 1 to 7 were excellent in coatability and Du after coating.
A molded product with less decrease in Pont impact strength can be obtained. On the other hand, the styrene content Fs of SEBS used as the component (c) is 10% by weight (Example 8) or 40% by weight.
(Example 9) If it deviates from the appropriate range, IZOD, after painting
DuPont decreases.

On the other hand, as in Comparative Example 1, as the polypropylene polymer of the component (A), PP-4 whose intrinsic viscosity of the xylene extraction component was as low as [η] E / P = 1.6 dl / g was used. If used, IZOD and paintability deteriorate. On the other hand, Comparative Example 2
As described above, as the polypropylene polymer of the component (A), the intrinsic viscosity of the xylene extraction component is [η] E / P = 5.5 dl / g.
If PP-5 is used, the IZOD, paintability and DuPont after painting deteriorate. Further, as in Comparative Example 3, the polypropylene polymer of the component (A) had an MFR of 1 g / 1.
When PP-6, which is extremely low at 0 minutes, was used, the performance was satisfied, but the appearance of the molded article was extremely poor. On the other hand, as in Comparative Example 4, when the MFR of the polypropylene polymer of the component (A) is too large (105 g / 10
Min), IZOD and DuPont after painting deteriorate.

Component (B): As an ethylene-octene rubber, EO-3 having an MFR as low as 0.3 g / 10 min (Comparative Example 5) and EO-4 having an MFR as high as 18 g / 10 min.
When (Comparative Example 6) was used, the paintability and the
nt, IZOD, paintability, and DuPont after painting occur. Further, as the component (B): ethylene-octene rubber, the octene content Fo is as low as 10% by weight, and EO is low.
When -5 is used (Comparative Example 7), IZOD, paintability, after painting
DuPont decreases, and when EO-6 as high as 40% by weight is used (Comparative Example 8), rigidity decreases.

When TB-4 having a low MFR (10 g / 10 min) was used as the component (c): triblock copolymer (Comparative Example 9), the decrease in DuPont after coating was large, and the MFR was low.
Using TB-5 (300 g / 10 min) with high (Comparative Example 1)
0), IZOD, poor paintability, large decrease in DuPont after painting. Furthermore, the critical energy release rate Gc of the flat interface between the component (c) and the xylene-insoluble component at 100 ° C. of the component (A) is low (10 J / m ² ).
The decrease in DuPont after painting is large. Further, when the component (c) is not used, the paintability and the decrease in DuPont after painting are large (Comparative Example 12).

Further, when UK-3 having a low HEMA modification amount (0.3% by weight) is used as the component (D) as in Comparative Example 13, the coatability is remarkably deteriorated. Similarly, when the component (D) is not used, the paintability is significantly deteriorated (Comparative Example 1).
4). When the particle size of the component (E) is large (5.6 μm) as in Comparative Example 15, the IZOD and DuPont strengths are reduced.

[0057]

The resin composition of the present invention is excellent in impact resistance and paintability, does not decrease impact strength after painting, and is particularly excellent in high-pressure car wash resistance. Materials that can be used in a wide range of fields.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining a method for evaluating high-pressure coating resistance.

FIGS. 2A and 2B are diagrams for explaining a method for evaluating high-pressure coating resistance, in which FIG. 2A is a side view and FIG. 2B is a top view.

FIG. 3 is a top view for explaining a method for evaluating high-pressure coating resistance.

Claims (3)

[Claims] 1. A component (A): a polypropylene-based polymer having a propylene-ethylene block copolymer; a component (B): an ethylene-octene-based rubber; and a component (C): a triblock copolymer. Component (D): a polypropylene polymer containing a modified polyolefin polymer having a hydroxyl group and component (E): talc, and having a propylene-ethylene block copolymer of component (A) at a temperature of 230 ° C. The melt flow rate measured under a load of 2.16 kg
The intrinsic viscosity of the xylene-extracted component at 140 ° C in decalin at 100 ° C for 10 minutes at 20 ° C is 2.0-5.0 g / dl, and the octene content of the ethylene-octene rubber of component (B) is as follows: Has a melt flow rate of 0.5-10 g / 10 min measured under the conditions of 15-35 wt% and a load of 2.16 kg at 230 ° C., and the component (C) triblock copolymer has a melt flow rate at 230 ° C. The melt flow rate measured under the condition of 2.16 kg
g / 10 minutes or more and 200 g / 10 minutes or less, 100 ° C of the triblock copolymer and the (A) propylene-ethylene block copolymer.
Energy release rate is 20 J / m ² when the phase angle of the flat interface with the xylene-insoluble component at -4 ° is -2 ° to -12 °
The content of component (C) in the total weight of component (A), component (B), component (C) and component (E) is 2-10.
The content of the unsaturated compound having a hydroxyl group in the modified polyolefin polymer having a hydroxyl group of the component (D) is 0.5-7% by weight.
Component (D) is added in an amount of 0.5 to 20 parts by weight based on 100 parts by weight of the total of component (A), component (B), component (C) and component (E). ) Talc has an average particle size of 5 μm or less, and the content of component (E) in the total weight of component (A), component (B), component (C) and component (E) is 5 to 25% by weight. % Of the resin composition. 2. The component (C) is a hydrogenated styrene-butadiene-styrene triblock copolymer,
The resin composition according to claim 1, wherein the content of styrene is 12 to 35% by weight. 3. The component (C) is a hydrogenated styrene-isoprene-styrene triblock copolymer,
The resin composition according to claim 1, wherein the content of styrene is 12 to 35% by weight.