JP3705515B2 - Polypropylene resin composition - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polypropylene resin composition, and more particularly, to a highly fluid polypropylene resin composition capable of forming a molded article having high rigidity, high impact strength, and high tensile elongation at break. .
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
In recent years, for the purpose of reducing the weight of automobile parts, automobile interior materials have been made thinner and lighter by a molding method such as a stamping mold method. Automotive interior materials, especially door rims, have high impact strength characteristics to ensure the safety of the human body and life of the driver and passengers against the side collision of the automobile, that is, the collision on the door side. Is needed. In particular, when adopting the stamping mold method, characteristics required for a raw material resin for automobile interior materials include high fluidity, high rigidity, and high impact strength characteristics.
[0003]
When an automobile interior material is molded by a stamping mold method, the raw material resin for the interior material needs to have high fluidity. In addition, simultaneous lamination and integral molding with a skin material (such as a two-layer sheet of PVC / polypropylene foam) may be performed. In this case, in order to prevent deformation due to stretching distortion of the skin material, the raw material resin for the interior material is required to have high rigidity. In addition, when the stamping molded product is removed from the mold, it will be deformed or damaged if there is no elongation, resulting in a defective product and a longer molding cycle.
[0004]
Incidentally, JP-A-7-304910 discloses
(A) 50 to 90 parts by weight of polypropylene having a melt flow rate at 230 ° C. of 10 to 70 g / 10 minutes;
(B) 0 to 25 parts by weight of an olefin copolymer rubber;
(C) For a total of 100 parts by weight with 5 to 40 parts by weight of inorganic filler,
(D) Modified polypropylene resin composition obtained by heat-treating a polypropylene resin composition containing 0.01 to 0.2 parts by weight of an organic peroxide and (E) 0.05 to 1 part by weight of a crosslinking aid Things are listed. The melt flow rate at 230 ° C. of the composition is in the range of 50 to 150 g / 10 minutes. The composition is used as a molding material for a stamping mold. This modified polypropylene resin composition has high fluidity and is excellent in impact strength and rigidity.
[0005]
However, it is possible to form a molded product with a high rigidity, high impact strength and a large tensile elongation at break, that is, a stamped molded product that can be easily removed from the mold, with a simpler manufacturing method. The appearance of a polypropylene resin composition is desired.
[0006]
OBJECT OF THE INVENTION
The present invention is a low-cost, high-flowability polypropylene resin composition capable of forming a molded product having high rigidity, high impact strength, and high tensile elongation at break, that is, a stamped molded product that can be easily removed from the mold. The purpose is to provide.
[0007]
SUMMARY OF THE INVENTION
The polypropylene resin composition according to the present invention is
(A) 50 to 95 parts by weight of polypropylene having a melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) of 10 to 100 g / 10 minutes;
(B) 3-45 parts by weight of ethylene / 1-butene copolymer rubber or ethylene / 1-octene copolymer rubber ;
(C) 2 to 45 parts by weight of inorganic filler [the total amount of components (A), (B) and (C) is 100 parts by weight]
(D) a polypropylene resin composition obtained by melt blending 0.005 to 0.2 parts by weight of an organic peroxide,
The polypropylene resin composition is
(i) The melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) is 50 to 150 g / 10 minutes,
(ii) Izod impact strength at 23 ° C. (with notch; ASTM D 628) is 100 J / m or more,
(iii) The tensile elongation at break (ASTM D 638) is 20% or more.
[0008]
The polypropylene resin composition is
(i) The melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) is 70 to 150 g / 10 minutes,
(ii) Izod impact strength at 23 ° C. (with notch; ASTM D 628) is 100 J / m or more,
(iii) The initial flexural modulus (ASTM D 790) at 23 ° C. is 1400 MPa or more,
(iv) The tensile elongation at break (ASTM D 638) is preferably 30% or more.
[0009]
The polypropylene resin composition according to the present invention as described above is suitable as a resin composition for stamping molds.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the polypropylene resin composition according to the present invention will be specifically described.
The polypropylene resin composition according to the present invention comprises a polypropylene (A), an amorphous or low crystalline α-olefin copolymer (B), an inorganic filler (C), and an organic peroxide (D). It is composed by melt blending.
[0011]
Polypropylene (A)
The polypropylene (A) used in the present invention has a melt flow rate (MFR; ASTM D 1238, 230 ° C., load 2.16 kg) of 10 to 100 g / 10 minutes, preferably 30 to 100 g / 10 minutes, more preferably 40 to 40%. It is in the range of 100 g / 10 minutes. The density is usually, 0.880~0.920g / cm ^3, preferably 0.895~0.915g / cm ^3, more preferably in the range of 0.900~0.910g / cm ^3.
[0012]
The type of the polypropylene (A) is not particularly limited, but a propylene homopolymer or a propylene / ethylene block copolymer having an ethylene content of 20 mol% or less is preferably used. When these polypropylenes (A) are used, a molded product having excellent rigidity can be obtained.
[0013]
Moreover, the above polypropylene (A) can be used individually or in combination of 2 or more types. For example, a propylene / ethylene block copolymer and a propylene homopolymer can be used in combination.
[0014]
In the present invention, polypropylene (A) is 50 parts by weight based on 100 parts by weight of the total amount of polypropylene (A), amorphous or low crystalline α-olefin copolymer (B) and inorganic filler (C). -95 parts by weight, preferably 60-80 parts by weight, more preferably 65-75 parts by weight.
[0015]
Amorphous or low crystalline α - olefin copolymer (B)
The amorphous or low crystalline α-olefin copolymer (B) used in the present invention is an amorphous or low crystalline random elastic copolymer comprising an α-olefin.
[0016]
As such an α-olefin copolymer (B), specifically,
Amorphous or low crystalline that does not contain diene components such as ethylene / propylene copolymer rubber, ethylene / 1-butene copolymer rubber, ethylene / 1-octene copolymer rubber, propylene / ethylene copolymer rubber α-olefin copolymer;
Ethylene / propylene / dicyclopentadiene copolymer rubber, ethylene / propylene / 1,4-hexadiene copolymer rubber, ethylene / propylene / cyclooctadiene copolymer rubber, ethylene / propylene / methylene norbornene copolymer rubber, ethylene -Ethylene / propylene / non-conjugated diene copolymer rubber such as propylene / ethylidene norbornene copolymer rubber;
Examples include ethylene / butadiene copolymer rubber.
[0017]
These amorphous or low crystalline α-olefin copolymers (B) can be used alone or in combination of two or more.
Among the α-olefin copolymers (B), saturated α-olefin copolymer rubbers such as ethylene / propylene copolymer rubber and ethylene / 1-octene copolymer rubber are preferable, and ethylene / 1-octene copolymer is particularly preferable. Polymer rubber is preferred. When these copolymers are used, a molded article having high impact strength can be obtained. Further, when an ethylene / 1-octene copolymer rubber having a 1-octene content of 15 to 35% by weight, preferably 20 to 30% by weight is used, a molded product having high impact strength and high tensile elongation at break can be obtained. Obtainable.
[0018]
The amorphous or low crystalline α-olefin copolymer (B) used in the present invention has a melt flow rate (MFR; ASTM D 1238, 190 ° C., load 2.16 kg) usually 1 to 50 g / 10 min. Preferably it exists in the range of 3-40 g / 10min, More preferably, it is in the range of 5-35 g / 10min. The density is usually in the range of 0.860 to 0.915 g / cm ³ , preferably 0.865 to 0.890 g / cm ³ , and more preferably 0.865 to 0.880 g / cm ³ . The crystallinity measured by the X-ray diffraction method is preferably 20% or less, particularly preferably 10% or less.
[0019]
In the present invention, the amorphous or low crystalline α-olefin copolymer (B) is composed of polypropylene (A), amorphous or low crystalline α-olefin copolymer (B) and inorganic filler ( It is used in a proportion of 3 to 45 parts by weight, preferably 5 to 30 parts by weight, more preferably 7 to 25 parts by weight with respect to 100 parts by weight of the total amount of C).
[0020]
Inorganic filler (C)
As the inorganic filler (C) used in the present invention, specifically, talc, silica, mica, calcium carbonate, glass fiber, glass beads, barium sulfate, magnesium hydroxide, wollastonite, calcium silicate fiber, carbon fiber, Examples thereof include magnesium oxysulfate fiber, potassium titanate fiber, titanium oxide, calcium sulfite, white carbon, clay, and calcium sulfate.
[0021]
These inorganic fillers (C) can be used alone or in combination of two or more.
Among the inorganic fillers (C), when talc is used, talc is preferably used because rigidity and impact strength of the obtained molded product are increased. In particular, talc having an average particle size of 0.1 to 3.0 μm, preferably 0.5 to 2.5 μm, is desirable because it contributes significantly to improving rigidity and impact strength.
[0022]
In the present invention, the inorganic filler (C) is 100 parts by weight of the total amount of the polypropylene (A), the amorphous or low crystalline α-olefin copolymer (B) and the inorganic filler (C). It is used in a proportion of 2 to 45 parts by weight, preferably 5 to 30 parts by weight, more preferably 7 to 25 parts by weight.
[0023]
Organic peroxide (D)
The organic peroxide (D) used in the present invention is desirably an organic peroxide having a decomposition temperature within a range of 150 to 270 ° C., preferably 170 to 190 ° C. with a half-life of 1 minute. Specifically, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (peroxide benzoate) hexyne-3, 1, 3-bis (t-butylperoxyisopropyl) benzene, lauroyl peroxide, t-butylperacetate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, 2,5-dimethyl -2,5-di (t-butylperoxy) hexane, t-butyl perbenzoate, t-butyl perphenyl acetate, t-butyl perisobutyrate, t-butyl per sec-octate, t-butyl perpivalate, Examples include cumyl perpivalate and t-butyl perdiethyl acetate.
[0024]
Among these, 1,3-bis (t-butylperoxyisopropyl) benzene, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) ) Hexin-3, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and the like are preferable. When these organic peroxides are used, the fluidity is remarkably improved, and a highly fluid polypropylene resin composition can be obtained.
[0025]
In the present invention, the organic peroxide (D) is 100 parts by weight of the total amount of polypropylene (A), amorphous or low crystalline α-olefin copolymer (B) and inorganic filler (C). And 0.005 to 0.2 parts by weight, preferably 0.005 to 0.1 parts by weight, and more preferably 0.01 to 0.05 parts by weight.
[0026]
Other components In the polypropylene resin composition according to the present invention, in addition to the components (A), (B), (C) and (D), a conventionally known crosslinking aid may be used, if necessary. Additives such as colorants, heat stabilizers, weathering stabilizers and the like can be blended within a range that does not impair the object of the present invention.
[0027]
Specific examples of the crosslinking aid include sulfur; divinyl compounds such as divinylbenzene; diallyl compounds such as diallyl phthalate; quinones such as p-quinonedioxime and p, p′-dibenzoylquinonedioxime. Dioxime compounds; maleimide compounds such as phenylmaleimide; triallyl cyanurate, triallyl isocyanurate, ethylene glycol methacrylate, polyethylene glycol methacrylate, 1,3,5-triacryloylhexahydro-s-triazine, liquid Examples include oligomers having a double bond in the main chain or side chain such as 1,2-polybutadiene, and polymers having a double bond in the main chain or side chain such as syndiocta-1,2-polybutadiene.
[0028]
In these, a divinyl compound, a maleimide compound, a quinone dioxime compound, especially divinylbenzene are preferable.
The crosslinking aid as described above is usually added in an amount of 0.1% relative to 100 parts by weight of the total amount of polypropylene (A), amorphous or low crystalline α-olefin copolymer (B) and inorganic filler (C). It is used in a proportion of 05 to 1 part by weight, preferably 0.05 to 0.7 part by weight, more preferably 0.1 to 0.5 part by weight.
[0029]
Polypropylene resin composition The polypropylene resin composition according to the present invention comprises a polypropylene (A) as described above, an amorphous or low crystalline α-olefin copolymer (B), and an inorganic filler (C). And an organic peroxide (D) or the like obtained by blending in a molten state.
[0030]
The polypropylene resin composition according to the present invention has a melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) in the range of 50 to 150 g / 10 minutes, preferably 70 to 150 g / 10 minutes.
[0031]
Further, this polypropylene resin composition has an Izod impact strength at 23 ° C. (with notch; ASTM D 628) of 100 J / m or more, an initial flexural modulus at 23 ° C. (ASTM D 790) of 1400 MPa or more, The tensile elongation at break (ASTM D 638) is 20% or more, preferably 30% or more. When the tensile elongation at break is 20% or more, the molded product can be easily removed without being deformed or damaged when the stamped molded product is taken out from the mold.
[0032]
The specific gravity of the polypropylene resin composition according to the present invention is usually 0.920 to 1.3.
Preparation of polypropylene resin composition The polypropylene resin composition according to the present invention having the above-mentioned physical properties is a polypropylene (A), an amorphous or low-crystalline α-olefin copolymer (B). It is obtained by melt-mixing a mixture containing an inorganic filler (C) and an organic peroxide (D) and other components blended as required. For example, when using a twin screw extruder, the screw front stage temperature is 120 to 200 ° C., preferably 140 to 160 ° C., the screw rear stage temperature is 180 to 270 ° C., preferably 200 to 260 ° C., and the rear stage temperature is higher than the front stage temperature. It is desirable to melt blend at high temperatures.
[0033]
If the temperature of the front stage of the screw is less than 120 ° C., the resin is insufficiently melted. On the other hand, if the temperature exceeds 200 ° C., polypropylene (A), an amorphous or low-crystalline α-olefin copolymer The kneading of (B) and the inorganic filler (C) becomes insufficient. Moreover, when the temperature of the latter stage of the screw is less than 180 ° C., the organic peroxide (D) is not completely decomposed. On the other hand, when this temperature exceeds 270 ° C., the physical properties of the obtained polyolefin resin composition are the target values. May be off.
[0034]
When the temperature at the front and rear stages of the screw is set to the above temperature conditions, a resin composition suitable for stamping molded products having high rigidity, high impact strength, and high tensile elongation at break can be provided, and a resin having high moldability. The composition can be prepared stably.
[0035]
The specific energy of the twin screw extruder is 0.1 to 0.5 kWh / kg, preferably 0.3 to 0.5 kWh / kg.
In addition, it is preferable to dry-blend each said component previously, before melt-kneading using an extruder.
[0036]
【The invention's effect】
The polypropylene resin composition according to the present invention provides a molded product having high fluidity, excellent moldability, high rigidity and impact strength, and high tensile elongation at break. In particular, when applied to stamping molding, it is possible to provide a stamping molded product that can be easily taken out from a mold.
[0037]
Therefore, the polypropylene resin composition according to the present invention is suitable as a resin for stamping molds, and automobile parts, for example, automobile interior materials such as door rims, console boxes, and instrument panels, distribution materials such as pallets and concrete panels, and construction materials. It can be used for housing materials such as bathroom panels and wallboard boards.
[0038]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited by these Examples.
[0039]
In addition, the component used by the Example and the comparative example is as follows.
Polypropylene (1) Propylene / ethylene block copolymer (hereinafter abbreviated as B-PP)
-Ethylene content: 7.0 mol%
MFR (ASTM D 1238, 230 ° C., load 2.16 kg): 80 g / 10 min Density: 0.890 g / cm ³
(2) Propylene homopolymer (hereinafter abbreviated as H-PP)
MFR (ASTM D 1238, 230 ° C., load 2.16 kg): 60 g / 10 min Density: 0.910 g / cm ³
Amorphous or low crystalline α - olefin copolymer (1) Ethylene / 1-octene copolymer rubber (hereinafter abbreviated as EOR-1)
・ Product name ENGAGE EG8200, manufactured by Dow Chemical
・ 1-octene content: 24.0% by weight
-Crystallinity: 6.5%
MFR (ASTM D 1238, 190 ° C., load 2.16 kg): 5.0 g / 10 min Density: 0.870 g / cm ³
(2) Ethylene / 1-octene copolymer rubber (hereinafter abbreviated as EOR-2)
・ Product name ENGAGE SM8400, manufactured by Dow Chemical
・ 1-octene content: 24.0% by weight
MFR (ASTM D 1238, 190 ° C., load 2.16 kg): 30.0 g / 10 min Density: 0.870 g / cm ³
(3) Ethylene / 1-octene copolymer rubber (hereinafter abbreviated as EOR-3)
・ Product name ENGAGE EG8150, manufactured by Dow Chemical
・ 1-octene content: 25.0% by weight
-Crystallinity: 3.5%
MFR (ASTM D 1238, 190 ° C., load 2.16 kg): 0.5 g / 10 min Density: 0.868 g / cm ³
(4) Ethylene / 1-octene copolymer rubber (hereinafter abbreviated as EOR-4)
・ Product name ENGAGE EG8100, manufactured by Dow Chemical
・ 1-octene content: 24.0% by weight
-Crystallinity: 5%
MFR (ASTM D 1238, 190 ° C., load 2.16 kg): 1.0 g / 10 min Density: 0.870 g / cm ³
(5) Ethylene / 1-butene copolymer rubber (hereinafter abbreviated as EBR)
-1-butene content: 18 mol%
Crystallinity: less than 1% MFR (ASTM D 1238, 190 ° C., load 2.16 kg): 3.6 g / 10 min Density: 0.86 g / cm ³
(6) Propylene / ethylene copolymer rubber (hereinafter abbreviated as PER)
-Ethylene content: 41 mol%
-Crystallinity: 0%
MFR (ASTM D 1238, 190 ° C., load 2.16 kg): 8.1 g / 10 minutes Density: 0.87 g / cm ³
(7) Ethylene / propylene copolymer rubber (hereinafter abbreviated as EPR)
Propylene content: 29 mol%
-Crystallinity: 4.8%
MFR (ASTM D 1238, 230 ° C., load 2.16 kg): 2.0 g / 10 min Density: 0.86 g / cm ³
Inorganic filler (1) Talc, made by Matsumura Sangyo Co., Ltd., trade name High filler 5000PJ
・ Average particle size: 2μm
Organic peroxide (1) 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3
(Hereafter, abbreviated as PH-25B)
・ Nippon Yushi Co., Ltd., trade name: Perhexine 25B
Moreover, the physical property measured about the polypropylene resin composition obtained by the Example and the comparative example, and its measurement test method are as follows.
(1) Melt flow rate (MFR)
The melt flow rate of the polypropylene resin composition was measured according to ASTM D 1238 (230 ° C., load 2.16 kg).
(2) Specific gravity The specific gravity of the polypropylene resin composition was measured according to ASTM D 1505 (in-water substitution method).
(3) Tensile strength at break (YS) and tensile elongation at break (EL)
A tensile test was performed according to ASTM D 638 (test piece type-IV, 23 ° C.) to determine the tensile strength at break (YS) and the tensile elongation at break (EL).
(4) Flexural strength (FS) and initial flexural modulus (FM)
A bending test was performed according to ASTM D 790 (23 ° C.), and bending strength (FS) and initial bending elastic modulus (FM) were determined.
(5) Izod impact strength (IZ)
An impact test was conducted according to ASTM D 628 (measurement temperature 23 ° C., 0 ° C.) to measure Izod impact strength (with notch).
[0040]
Examples 1-5 and Comparative Examples 1-7
Each component of the polypropylene resin composition shown in Table 1 was dry blended using a Henschel mixer manufactured by Mitsui Miike Seisakusho at the blending ratio shown in Table 1, and then a twin screw extruder [manufactured by Kobe Steel, Ltd., Using KTX, screw diameter = 46 mm, L / D = 43.8], the mixture was melt-kneaded to obtain pellets.
[0041]
The kneading conditions were as follows.
<Kneading conditions>
-Screw rotation speed of twin screw extruder: 450rpm
・ Specific energy of twin screw extruder: 0.3 to 0.5 kWh / kg
-Resin extrusion rate: 80 kg / Hr
・ Set temperature at 4 locations in front of cylinder: 140 ℃
-Six set temperatures at the rear of the cylinder: 180 ° C, 180 ° C, 240 ° C, 240 ° C, 240 ° C, 240 ° C, 180 ° C in order
MFR (230 ° C.), specific gravity, tensile breaking strength (YS), tensile elongation at break (EL), bending strength (FS), initial flexural modulus (FM) of the polypropylene resin composition obtained as described above. ) And Izod impact strength were determined according to the above measurement method.
[0042]
The results are shown in Table 1.
[0043]
[Table 1]

Claims (3)

(A) 50 to 95 parts by weight of polypropylene having a melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) of 10 to 100 g / 10 minutes;
(B) 3-45 parts by weight of ethylene / 1-butene copolymer rubber or ethylene / 1-octene copolymer rubber ;
(C) 2 to 45 parts by weight of inorganic filler [the total amount of components (A), (B) and (C) is 100 parts by weight]
(D) a polypropylene resin composition obtained by melt blending 0.005 to 0.2 parts by weight of an organic peroxide,
The polypropylene resin composition is
(i) The melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) is 50 to 150 g / 10 minutes,
(ii) Izod impact strength at 23 ° C. (with notch; ASTM D 628) is 100 J / m or more,
(iii) A polypropylene resin composition having a tensile elongation at break (ASTM D 638) of 20% or more. The polypropylene resin composition is
(i) The melt flow rate (ASTM D 1238, 230 ° C., load 2.16 kg) is 70 to 150 g / 10 minutes,
(ii) Izod impact strength at 23 ° C. (with notch; ASTM D 628) is 100 J / m or more,
(iii) The initial flexural modulus (ASTM D 790) at 23 ° C. is 1400 MPa or more,
(iv) The polypropylene resin composition according to claim 1, wherein the tensile elongation at break (ASTM D 638) is 30% or more. The polypropylene resin composition according to claim 1 , wherein the polypropylene resin composition is a stamping mold resin composition.