JPH0613626B2 - Polypropylene composition - Google Patents

Description

The present invention relates to a polypropylene composition having excellent impact resistance, rigidity and surface gloss.

Although crystalline polypropylene is excellent in rigidity, heat resistance, surface gloss, etc., it has the drawback of low impact strength, especially impact resistance at low temperatures. Conventionally, various polypropylene compositions of polypropylene and a rubber-like substance such as polyethylene, polyisobutylene, polybutadiene, and an amorphous ethylene / propylene copolymer have been proposed for the purpose of improving this drawback. However, when these compositions are used as materials for molding processing such as compression molding and injection molding, the gloss of the surface is lower than that of polypropylene alone, and the commercial value of the product is often lost. As a solution, a method of reducing the amount of polyethylene that causes a decrease in gloss,
Alternatively, in the case of copolymerized polypropylene, a method of reducing the ethylene content or the like can be considered, but the low temperature impact strength is lowered and the use is limited by any means. It has been found that the use of polypropylene having a low molecular weight can improve the glossiness, but in this case also, the impact strength such as tensile strength is lowered, and a sufficiently satisfactory product cannot be obtained.

In view of such a situation, the present inventor has conducted various studies to obtain a polypropylene composition having excellent impact resistance, rigidity, surface gloss, and even surface gloss, and as a result, substantially amorphous polymers having different melt viscosities are obtained. It has been found that the above object can be achieved by mixing the ethylene / α-olefin random copolymer (1) with polypropylene and the present invention has been accomplished.

That is, the present invention has an intrinsic viscosity [η]: 1.1 to 2.3 dl
/ g of propylene homopolymer or propylene and 4
Random or block copolymer (A) with 0 mol% or less of other α-olefin (hereinafter sometimes simply referred to as "polypropylene (A)") 35 to 90% by weight, ethylene content 35 to 85 mol %, Intrinsic viscosity [η]: 1.1 to 1.7 dl / g and substantially amorphous ethylene / α-olefin random copolymer (B) 2 to 35% by weight, and ethylene content 35 to 85 mol%, Impact resistance, which is characterized by comprising an intrinsic viscosity [η]: 1.9 to 3.8 dl / g and a substantially amorphous ethylene / α-olefirandum copolymer (c) of 2 to 35% by weight, It is intended to provide a polypropylene composition which is excellent in rigidity and surface gloss and has no uneven gloss on the surface.

In the present invention, "substantially amorphous" means that the crystallinity by X-ray is 5% or less.

Polypropylene (A) used in the present invention is a decalin solvent,
A homopolymer of propylene having an intrinsic viscosity [η] at 135 ° C. of 1.1 to 2.3 dl / g, preferably 1.3 to 2.0 dl / g or propylene and other α-olefins at 40 mol% or less, eg ethylene, 1 -Buden, 1-Hexen, 4
-Random or block copolymer with methyl-1-pentene, 1-octene, etc. Among these, a propylene homopolymer, preferably a propylene homopolymer having an isotactic index of 90 or more, more preferably 95 or more and an ethylene content of 5 to 40 mol%, preferably 10 to 35 mol% of propylene Ethylene block copolymers are preferable, and propylene / ethylene block copolymers are more preferable from the viewpoint of low temperature impact resistance. As the propylene / ethylene block copolymer, impact resistance, from the balance of rigidity, isotactic index 90 or more, further 95 or more propylene polymer component (I) 60 to 9
0 wt%, or even 70-80 wt%, 2 propylene units
Propylene / ethylene copolymer component (II) containing 0 to 80 mol%, more preferably 40 to 80 mol%: 1 to 30 wt%, further 3 to 25 wt%, and an intrinsic viscosity [η] of 2.
Polyethylene component (III) of 0 dl / g or more or ethylene copolymer component having a propylene unit content of 10 mol% or less
(IV): A propylene / ethylene block copolymer obtained by sequentially polymerizing ethylene and propylene, which is composed of 1 to 30% by weight, more preferably 3 to 25% by weight, is particularly preferable. When a propylene / ethylene block copolymer is used, the propylene / ethylene copolymer component (II) in the block copolymer has an intrinsic viscosity [η], and thus the ethylene / α-olefin random copolymer described below is used. It is added to either (B) or the ethylene / α-olefin random copolymer (C).

The propylene / ethylene block copolymer can be obtained by polymerizing olefins in one polymerization reaction system in the presence of a stereoregular catalyst, preferably a catalyst comprising a transition metal component with a support and an organoaluminum compound. , A so-called non-polymer blend type copolymer,
As a concrete method, Japanese Patent Laid-Open No. 52-98045 by the present applicant is used.
No. and Japanese Patent Publication No. 57-26613.

The propylene / ethylene block copolymer is not necessarily limited to one kind of polymer obtained by polymerizing in one polymerization reaction system, and two or more kinds of propylene / ethylene block copolymers separately polymerized may be used. It may be a mixture.

The ethylene content in the present invention is a value measured by the ¹³ C-NMR method, and the isotactic index (II) represents the boiling n-heptane insoluble content in% by weight. The intrinsic viscosity [η] is a value measured at 135 ° C in a decalin solvent.

The ethylene / α-olefin random copolymer (B) used in the present invention has an ethylene content of 35 to 85 mol%, preferably 37 to 82 mol%, and an intrinsic viscosity [η] of 1.1 to 1.1.
1.7 dl / g, preferably 1.2 to 1.6 dl / g and substantially amorphous, and having a crystallinity by X-ray of 5% or less. When the ethylene content is out of the above range or when the crystallinity exceeds 5%, the effect of improving impact resistance, particularly low temperature impact resistance, is small. Also, the intrinsic viscosity [η] is 1.7d
If it exceeds l / g, there is no effect of improving the surface gloss, and 1.1dl /
If it is less than g, the impact resistance is lowered.

The ethylene / α-olefin random copolymer (C) used in the present invention has an intrinsic viscosity [η] of 1.9 to 3.8 dl / g, preferably 2.3 to 3.0 dl / g, except that the ethylene content and crystallization are in the range. The degree is the same as that of the ethylene / α-olefin random copolymer (B). Intrinsic viscosity [η] is 3.8 dl / g
If it exceeds the range, the melt fluidity is poor, the moldability of the composition is deteriorated, and gloss unevenness is likely to occur. Intrinsic viscosity is 1.9d
If it is less than 1 / g, the impact resistance cannot be improved.

Specific examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and the like. Also a copolymer (B)
And the copolymer (C) is a small amount of a diene monomer, and later dicyclopentadiene, ethylidene norbornene, 1,4-
Hexadiene and the like may be copolymerized.

The polypropylene composition of the present invention is the polypropylene described above.
(A) 35 to 90% by weight, preferably 40 to 70% by weight,
The ethylene / α-olefin random copolymer (B) 2
To 35% by weight, preferably 3 to 30% by weight, and 2 to 35% by weight, preferably 3 to 30% by weight of the ethylene / α-olefin random copolymer (C), and preferably MFR of polypropylene composition. Is 4 or 2
Those in the range of 0 g / 10 min are excellent in balance of moldability, impact resistance, mechanical strength and the like.

If the amount of polypropylene (A) is less than 35% by weight, the rigidity and surface gloss are poor, while if it exceeds 90% by weight, the impact resistance is poor.

When the amount of the ethylene / α-olefin random copolymer (B) is less than 2% by weight, the surface gloss is not improved, and uneven gloss is likely to occur. On the other hand, if it exceeds 35% by weight, the mechanical strength decreases.

When the amount of the ethylene / α-olefin random copolymer (C) is less than 2% by weight, impact resistance, particularly impact resistance at low temperature, is not improved. On the other hand, when it exceeds 35% by weight, melt flowability decreases, Poor moldability. The ethylene / α-olefin random copolymer (B) and the ethylene / α-olefin random copolymer (C) have a weight ratio (B) / (C) of 1/6 or more, further 1/3.
Above all, the surface gloss is particularly improved.

The polypropylene composition of the present invention is polypropylene
(A), ethylene / α-olefin random copolymer (B) and ethylene / α-olefin random copolymer (C) within the above ranges, for example, Henschel mixer, V-blender, ribbon blender, tumbler blender, etc. It is obtained by melt-kneading with a single-screw extruder, a multi-screw extruder, a kneader, a Banbury mixer, etc. Among them, a high-quality polypropylene composition in which each component is uniformly dispersed can be obtained by using a device having excellent kneading performance such as a multi-screw extruder, a kneader, a Banbury mixer, or the like.

The polypropylene composition of the present invention, the polypropylene (A), ethylene-α-olefin random copolymer (B)
And, in addition to the components of the ethylene / α-olefin random copolymer (C), for the purpose of improving rigidity, polypropylene composition: 15 parts by weight or less, further 10 parts by weight per 100 parts by weight.
Ordinary average particle diameter of 0.5 parts by weight or less is 0.5 to 5μ, and further 1
To 3μ talc and / or polypropylene composition:
Polyethylene having an intrinsic viscosity [η] of 2.8 dl / g or less may be added in an amount of 50 parts by weight or less, further 45 parts by weight or less, relative to 100 parts by weight. However, if the amount of talc exceeds 15 parts by weight, impact resistance and surface gloss will decrease, and if the amount of polyethylene exceeds 45 parts by weight, fluidity will decrease, and the intrinsic viscosity [η] will be 2.8 dl / g. Addition of more than 10% lowers the surface gloss, and any of them defeats the purpose of the present invention.

The polypropylene composition of the present invention, in addition to the talc and polyethylene, at any stage of mixing thereof, an antioxidant, an ultraviolet absorber, a lubricant, a nucleating agent, an antistatic agent, a flame retardant,
In addition to pigments, dyes, or talc, other compounding agents such as other inorganic or organic fillers and reinforcing agents can be added within the range not impairing the object of the present invention.

INDUSTRIAL APPLICABILITY The polypropylene composition of the present invention is excellent in impact resistance, rigidity and surface gloss, and does not cause unevenness of surface gloss, and also has good dimensional stability and paintability. It is particularly suitable for large-sized molded articles for automobile interiors and exteriors such as trims, but is not limited thereto, and is also suitably used for housings for weak electric appliances, machine tools, and electric tools.

Next, the present invention will be described more specifically with reference to Examples.
The present invention is not limited to these examples unless it exceeds the gist.

Example 1 II: 97 propylene polymer component (hereinafter abbreviated as PP (A)): 77.4 wt%, propylene content: 60 mol%, crystallinity by X-ray 3% and [η]: 3 dl / g propylene·
Ethylene copolymer component (hereinafter abbreviated as PEC (A)): 5: 1 wt% and [η]: 3.3 dl / g polyethylene component (hereinafter abbreviated as PE (A)): 17.
Ethylene content consisting of 5% by weight: 26 mol% and MFR: 14
g / 10 min propylene / ethylene block copolymer (hereinafter abbreviated as PEB-I): 70% by weight, ethylene content: 81.0
Mol%, intrinsic viscosity [η]: 1.38 dl / g and crystallinity: 3%
Ethylene-propylene random copolymer (hereinafter EPR-
Abbreviated as I): 10% by weight, ethylene content: 81.0 mol%, intrinsic viscosity [η]: 2.60 dl / g, and crystallinity: 3% ethylene-propylene random copolymer (hereinafter abbreviated as EPR-II). : 20% by weight, PEB-I + EPR-I + EPR-II = 100
Heat stabilizer against parts by weight (trade name: Yoshinox BHT, Yoshitomi Pharmaceutical Co., Ltd .: 0.1 parts by weight and brand name: Irganox 1010)
Musashino Geigy Co., Ltd. (0.1 part by weight) is mixed with a Hensiel mixer, and then a twin-screw extruder (Werner & Pfleider
Composition-I was obtained by granulating at a resin temperature of 220 ° C. using ZSK 53L manufactured by er. Next, the composition-I was injected into an injection molding machine (Dynamelter-SJ-45C, mold clamping force 140TON manufactured by Meiki Seisakusho Co., Ltd.).
With a resin temperature of 200 ° C (130 mm × 120 mm × 3 mm
t) and test pieces were molded, and the surface gloss was evaluated for the former molded product and other items were evaluated for the latter molded product. A granulating pellet was used for MFR measurement. The results are shown in Table 1.

MFR (g / 10min): ASTM D 1238, L Surface gloss (Gloss) (%): ASTM D 523 Incident angle 60 degree Bending initial elastic modulus (kg / cm ² ): ASTM D 790 Izod impact strength (Izod-30 ° C) (Kg · cm / cm): ASTM D 256 Low temperature embrittlement temperature (° C): ASTM D 746 Example 2 Instead of the composition-I used in Example 1, PEB-I used in Example 1 was used. , EPR-I and EPR-II mixed amounts of 70 each
Example 1 was repeated except that the composition-II was used in the amounts of 5% by weight, 5% by weight and 25% by weight. The results are shown in Table 1.

Comparative Example 1 Instead of the composition-I used in Example 1, PEB-I used in Example 1 was 70% by weight and EPR-II was 30% by weight.
Example 1 was repeated except that the composition-III was used. The results are shown in Table 1.

Example 3 Instead of PEB-I used in Example 1, II: 98 propylene polymer component (hereinafter abbreviated as PP (B)): 73.2% by weight, propylene content: 50 mol%, crystal by X-ray Degree of conversion: 5% and ultimate [η]: 3.3 dl / g propylene / ethylene copolymer component (hereinafter abbreviated as PEC (B)): 21.6 wt% and intrinsic viscosity [η]: 4.8 dl / g polyethylene component (Hereafter abbreviated as PE (B)): 5.2 wt% ethylene content: 22.8 mol%
And MFR: 12.2 g / 10 min propylene / ethylene block copolymer (hereinafter abbreviated as PEB-II): 74 parts by weight, EPR-I used in Example 1: 16 parts by weight, EPR-II: 10 parts by weight Example 1 was repeated except that the composition IV was added in an amount of 5.3 parts by weight of talc (trade name: Micron White 5000P, manufactured by Hayashi Kasei Co., Ltd.) per 100 parts by weight of the composition. The results are shown in Table 1.

Example 4 Except that the composition V used in Example 1 was replaced with the composition V used in Example 1 in which the amounts of PEB-I and EPR-I were 70% by weight and 30% by weight, respectively. The same procedure as in Example 1 was performed. The results are shown in Table 2.

Example 5 Instead of PEB-I used in Example 1, II: 98 propylene copolymer component (hereinafter abbreviated as PP (C)): 72.0% by weight,
Propylene content: 50 mol%, X-ray crystallinity: 5
% And intrinsic viscosity [η]: 2.2 dl / g propylene ethylene copolymer component (hereinafter abbreviated as PEC (C)): 22.5% by weight and intrinsic viscosity [η]: 3.3 dl / g polyethylene component (hereinafter PE (C) )
Abbreviated): ethylene content consisting of 4.5% by weight: 25.5 mol% and MFR: 40 g / 10 min 77 parts by weight of propylene / ethylene block copolymer (hereinafter abbreviated as PEB-III), EPR-I used in Example 1 : 7.7 parts by weight, and ethylene content 40
Mol%, [η]: 3.0 dl / g, crystallinity: 0%, propylene / ethylene random copolymer (hereinafter abbreviated as EPR-III): 15.3 parts by weight Example 1 In the same manner as in Example 1 except that the composition VI was added in which the tackle used in 3 was 7.7 parts by weight and the intrinsic viscosity [η] was 2.0 dl / g polyethylene (hereinafter abbreviated as PE-I): 45 parts by weight. I went. The results are shown in Table 2.

Comparative Example 2 PEB-I used in Example 1 was processed in the same manner as in Example 1. The results are shown in Table 2.

Example 6 Instead of EPR-II used in Example 3, used in Example 5.
EPR-III: The same procedure as in Example 3 was carried out except that 10 parts by weight of the composition VII was used. The results are shown in Table 2.

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Claims (1)

[Claims] 1. Intrinsic viscosity [η]: 1.1 to 2.3 dl / g propylene homopolymer or propylene and 40 mol%
Random or block copolymers (A) with other α-olefins (A) 35 to 90% by weight, ethylene content 35 to 85 mol%, intrinsic viscosity [η]: 1.
2 to 35% by weight of a substantially amorphous ethylene / α-olefin random copolymer (B) at 1 to 1.7 dl / g, and an ethylene content of 35 to 85 mol%, intrinsic viscosity [η]: 1.
A polypropylene composition comprising 9 to 3.8 dl / g and substantially amorphous amorphous ethylene / α-olefin random copolymer (c) 2 to 35% by weight.