JPS62256856A - Polypropylene composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. having excellent impact resistance, rigidity, coatability and moldability, consisting of a specified propylene/ethylene block copolymer, an ethylene/alpha-olefin random copolymer and talc or CaCO3. CONSTITUTION:50-77% (by weight; the same applies hereinbelow) propylene polymer having an isotaticity index of not lower than 90 is copolymerized with 20-35% propylene/ethylene copolymer having an ethylene content of 20-90mol% and an intrinsic viscosity of 1.0-5.0dl/g and 3-30% ethylene polymer having an ethylene content of 30-100mol% and an intrinsic viscosity of 1.0-10.0dl/g to obtain a propylene/ethylene block copolymer (A) having an ethylene content of 15-40wt% and an MFR of 5-30g/10min. 98-55% component A is melt-kneaded with 0-25% ethylene/alpha-olefin copolymer (b) having an ethylene content of 5-95mol%, an MFR of 0.1-10g/10min and a crystallinity index of not higher than 70% as measured with X-rays and 2-20% talc or CaCO3 (C) having an average particle size of 0.1-5mu.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a polypropylene composition with improved impact resistance, rigidity, paintability, and moldability, and more particularly, to a polypropylene composition that is particularly suitable for use in automobile bumpers having excellent impact resistance, rigidity, paintability, and moldability. The invention relates to polypropylene compositions suitable for forming.

11 Technical problems and problems 1. Raw polypropylene has excellent rigidity, heat resistance, surface gloss, etc., but has low impact strength, especially at low temperatures, and is poor in paintability. There is a problem. Therefore, its application to fields where impact strength is required or where painting is required is limited.

Many methods have been proposed in the past for the purpose of improving these drawbacks by mixing crystalline polypropylene with a rubbery substance such as polyethylene, polypropylene, polybutadiene, or an amorphous ethylene/propylene copolymer. In order to improve the decrease in rigidity caused by the addition of these rubbery substances, it has also been proposed to add and mix a WaX filler such as talc.

For example, Japanese Patent Application Laid-open No. 57-55952 discloses that the ethylene content is 5 to 10% by weight, and the content is 5 to 10% by weight.
Crystalline ethylene-pyrene copolymer with MFR) of 2 to 10 g/10 min, intrinsic viscosity of 2.0
A polypropylene composition for bumper formation consisting of an amorphous ethylene-propylene copolymer of ~3.5 and talc has been disclosed, and JP-A-57-15984'1 discloses a composition containing high-density polyethylene. Added polypropylene compositions are disclosed. However, JP-A-57-55
In the polypropylene composition disclosed in Publication No. 952,
The ethylene content of the ethylene/propylene block copolymer, which is the main component, is as low as 5 to 101%, and the melt flow rate is as low as 2 to 109/10 minutes.
There were problems in that the impact resistance was not sufficient and the moldability was also poor. On the other hand, the polypropylene composition disclosed in JP-A-57-159841 overcomes the insufficient impact resistance of high-density polyethylene due to the low ethylene content of the ethylene-propylene block copolymer. This is an attempt to improve the quality by adding high-density polyethylene, but when high-density polyethylene is added, the polyethylene may not be dispersed uniformly into the polypropylene, resulting in problems such as poor paintability of molded products. was there. In order to solve these problems, the applicant has
-13838, (a) the ethylene content is 15 to 35 mol% and the melt flow rate is 10 to 6
0g/10min propylene-ethylene block copolymer 50-70% by weight, (b) ethylene content 60-85
Disclosed is a polypropylene composition comprising 25 to 40 x ω% of an ethylene/α-olefin random co-metal alloy having a melt flow rate of 0.1 to 2y/10 min and a crystallinity of 10 or less by X-rays. .

This boria [copylene composition is lacking in impact resistance, rigidity, and paintability, but the content of component (b), ethylene/α-olefin random copolymer, is high at 25 to 40% by weight. Therefore, there were problems in that the moldability was somewhat inferior and the appearance was not necessarily satisfactory9.

OBJECT OF THE INVENTION The present invention solves the problems associated with the above-mentioned prior art, and provides improved impact resistance, rigidity, paintability, and moldability, as well as a balance among the above-mentioned properties. The purpose is to provide a polypropylene composition with excellent properties.

Summary of the Invention The polypropylene composition according to the present invention comprises: [A] Propylene/ethylene block copolymer: 98 to 55% by weight This propylene/ethylene block copolymer has the following composition and has an ethylene content of 15% by weight. ~40'Ele% and the melt flow rate is 5-30 cJ/10 min.

(I) Propylene polymer component having an isotube index of 90 or more...50 to 77% by weight (L) ethylene content of 20 to 90% by weight, and an intrinsic viscosity of 1.0 to 5.
Od. Propylene/ethylene copolymer component with fl/y: 20 to 35 weight ω% (In) with an intrinsic viscosity of 1.0 to 10. Od. Ethylene polymer component with II/g...3 to 30 times I■? Also [B]
Ajiren α-A reflex random combination m combination: 0~25
Weight% This ethylene/α-olefin random copolymer has an ethylene content of 5 to 95 mol%, a melt flow rate of 0.1 to 10.0 g/10 minutes, and a crystallinity of 70% by X-rays. It's below.

[C] Talc or calcium carbonate: 2-20% by weight This talc or calcium carbonate has an average particle size of 0.1-20% by weight.
It is characterized by having a thickness of 5.0μ.

The polypropylene composition according to the present invention comprises a propylene-ethylene block copolymer of specified nature and amount;
It is composed of ethylene/α-olefin random copolymer, which is a rubber component with a specific m content, and tartar or calcium carbonate with a specific ω content, so it has excellent impact resistance, rigidity, paintability, and moldability. It has an excellent balance of the characteristics mentioned above, and a bumper with excellent performance can be obtained, especially when used as a bumper for an automobile.

DETAILED DESCRIPTION OF THE INVENTION The polypropylene composition according to the present invention will be explained in detail below.

The polypropylene composition according to the present invention contains [A] a propylene/ethylene block copolymer, [B] an ethylene/α-olefin random copolymer, and [C] talc or calcium carbonate as essential components. Each of the above components will be explained below.

Propylene/ethylene block copolymer [A] Propylene/ethylene block copolymer has an ethylene content of 1
5 to 40 mol%, preferably 20 to 30 mol%,
Melt flow rate 1 (MFR: ASTM D 1
238 1>h15-30g/10min, preferably 10
~30g/10 minutes of copolymer.

This propylene-ethylenebutylene copolymer [A] contains the following three components (1), (II) and (1).
It consists of

(I) Isotactic index is 90 or more preferably 95
The propylene polymer component is 50 to 77% by weight, preferably 60 to 70% by weight (If) the intrinsic viscosity [η] is 1.0 to 5. Qd, Q/J preferably 2.0-3. Propylene-ethylene copolymer component having OdU/g and an ethylene content of 20 to 90 mol%, preferably 40 to 60 mol%: 20 to 35 mol%, preferably 20 to 30 mol% (■) 4*Limiting viscosity [η] is 1.0 to 10. Odd/g Preferably 2.0 to 4.5 (jQ /9 Ethylene polymer component: 3 to 30 weight %, preferably 5 to 12 weight ω% This propylene-ethylene block copolymer [△]
It is preferable that each of the above components (I>(1[)J'> and (1) are sequentially polymerized to form a co-m polymer.

A propylene/ethylene block copolymer (A) with an ethylene content of less than 15 mol% has insufficient impact resistance, while a propylene/ethylene block copolymer (A) with an ethylene content of less than 40 mol% is undesirable because of poor rigidity. Also, the melt flow rate is 5s/1
If it is less than 0 minutes, the moldability will be poor due to poor fluidity when melted, while if it exceeds 30 g/10 minutes, it will be undesirable because mechanical strength such as impact resistance will be poor. If the isotactic index of the propylene polymer component (I) constituting the propylene/ethylene block copolymer [AI] is less than 90, it is not preferable because the rigidity is insufficient.

In addition, the propylene/ethylene block copolymer [A]
Propylene/ethylene copolymer component (II) constituting
If the extreme viscosity [η1 is less than 1.0, the strength of the molded product will be insufficient and stickiness will occur on the surface, which is undesirable. On the other hand, if it exceeds 5.0, J3 will be present in the composition and will cause poor dispersion. As a result, impact resistance and gloss are deteriorated, which is not preferable. (Here, the ethylene content of this propylene/diethylene copolymer component is 20%)
If it is less than 90% by mole, the strength of the molded product will be insufficient, which is undesirable.On the other hand, if it exceeds 90 mol %, the rigidity of the molded product will be insufficient.

This propylene/ethylene copolymer component (II) is a propylene/ethylene block copolymer [A
], but this cloth has a heavy burden of 20-35%.
If it is less than 1%, the strength of the molded product will be insufficient, which is undesirable. On the other hand, if it exceeds 35%, the rigidity and heat resistance of the molded product will be insufficient.

The ethylene polymer component (III) constituting the propylene/ethylene block copolymer [A] has an extreme viscosity [η] of 1.0 to 10.0;
i1. If it is less than 0, the strength of the molded product will be insufficient, which is undesirable. On the other hand, if it exceeds 3.5, the gloss and impact resistance of the molded product will become unstable, which is not preferred.

Furthermore, this ethylene component (III), as described above,
Propylene/ethylene block copolymer [A] 3-3
It exists in 61 with 0 weight ω%, but this cloth is 3 壬 [d″′3
A content of less than 6'36 is preferable because the strength of the molded product will be insufficient, while a content exceeding 30% by weight is not preferred because the rigidity of the molded product will be insufficient.

The above pyrene-ethylene block (polymer [A]
is a so-called non-polymer obtained by combining olefins in one polymerization reaction system in the presence of a stereoscopic (11) catalyst, preferably a catalyst consisting of a supported transition metal component and an organoaluminum compound. It is a blend type copolymer, and the specific manufacturing method is described in Japanese Patent Application Publication No. IKi 52-98045 and Japanese Patent Publication No. Sho 57-
It is explained in detail in No. 26613.

The propylene/ethylene block copolymer [A] is
Further, the polymer is not necessarily limited to one type of polymer obtained by combining in one polymerization reaction system, but may be a mixture of two or more types of propylene/ethylene block copolymers polymerized separately.

a3, in this specification, Ejiren S is present (■ is 1
This is a value measured by 3C-NMR method, and the isotactic index (II) is the weight percent of boiling n-hebutane insoluble matter.
It must be expressed as . Moreover, the intrinsic viscosity [η] means a value measured at 135° C. using a decalin solvent.

Ethylene/α-olefin random copolymer [B] The ethylene/α-olefin random copolymer [B] used in the present invention has an ethylene content of 5 to 95 mol%, preferably 30 to 90 mol%. , melt flow rate is 0.1 to 10 g/10 min, preferably 0.3 to 8.0 y/
10 minutes, and the crystallinity by X-ray measurement is 70% or less, preferably 5% or less.

If the ethylene content is less than 1 mol %, the strength of the molded article will be insufficient, which is undesirable. On the other hand, if it exceeds 95 mol %, the rigidity of the molded article will be insufficient. In addition, the melt flow rate (MFR) is 0.1g/
If it is left for less than 10 minutes, it is not preferable because it causes poor dispersion in the composition, resulting in a decrease in the impact resistance of the molded product.
On the other hand, if it exceeds 10 U/10 minutes, the surface of the molded product becomes sticky and the strength decreases, which is not preferable.

Furthermore, if the crystallinity by X-ray measurement exceeds 70%,
This is not preferable because it causes a decrease in the 'dlr2 resistance of the molded product.

Specifically, the α-olefins include propylene, 1-butene, 1-hexeno, 4-methyl-1-
Examples include pentene. Further, the copolymer ['B] may be copolymerized with a small amount of a diene monomer such as dicyclopentadiene, ethylidene norbornene, 1,4-h21-nisadiene, or the like.

The ethylene/α-olefin random copolymer [B]
is usually produced using a combination catalyst of a vanadium compound and an organoaluminum compound.

Specifically, for example, hexane is used as a solvent, vanadium oxytrichloride is added to this, and then ethylene and α
- It can be produced by dissolving and saturating a mixed gas of olefins, and then adding a solution of ethylaluminum methane:1:chloride dissolved in hexane in advance.

This ethylene/α-olefin random copolymer [8] is present in the polypropylene composition of Mokkomei.
It is present in an amount of ~25% by weight, preferably from 5 to 20% by weight, and preferably from 10 to 20% by weight. This ethylene
α-olefin random copolymer [B] is 25%
If it is present in the polypropylene composition according to the present invention in an amount exceeding 100%, it is not preferable because it causes a decrease in the heat resistance rigidity of the molded article.

Talc or HM Calcium [C] The talc or HM calcium dioxide used in the present invention is usually commercially available as an inorganic filler.

In the case of talc, those having an average particle diameter of 0.1 to 5 microns, preferably 1 to 3 microns are used. If the average particle size is less than 0.1 μm, it becomes difficult to disperse uniformly in the resin, which is undesirable, while if it exceeds 5 μm, the low-temperature impact resistance of the molded product becomes insufficient, which is not preferred.

In the case of calcium carbonate, its average particle size is 0.1 to 5
μm Preferably, those in the range of 0.5 to 3 μm are used. This J: eel talc or mW calcium can be used alone or in combination.

In the present invention, talc or calcium carbonate is present in the polypropylene composition in an amount of 2 to 20% by weight, preferably 5 to 18% by weight, more preferably 5 to 15% by weight.

If this amount is less than 2% by weight, the molded product will lack heat-resistant rigidity, which is undesirable, while if it exceeds 20% by weight, the molded product will have insufficient low-temperature impact resistance, which is undesirable.

Manufacturing method The polypropylene composition of the present invention is produced by combining a propylene/ethylene block copolymer [A1, an ethylene/α-olefin random copolymer [B], and talc or calcium carbonate [C] in the above-mentioned 1,000 M range, for example, by Henschel. It can be obtained by mixing in a mixer, 1-blender, ribbon blender, tumbler blender, and then melt-kneading in a single-screw extruder, multi-screw extruder, kneader, Banbury mixer, etc. Among them, by using equipment with excellent kneading performance such as a multi-screw extruder, kneader, and Banbury mixer, 1 q of high-quality polypropylene compositions in which each component is more uniformly dispersed can be obtained.

The polypropylene composition of the present invention may contain antioxidants, ultraviolet absorbers, lubricants, nucleating agents, antistatic agents, flame retardants, pigments, dyes or other ionic agents other than talc and calcium carbonate at any stage of its mixing. Various fillers such as fillers and reinforcing agents can be blended within the range that does not impair the purpose of the present invention.

Effects of the Invention The polypropylene composition according to the present invention has excellent impact resistance, rigidity, and paintability, and also has excellent melt flowability, so it has excellent moldability, and is particularly suitable for forming automobile bumpers. There is.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A polypropylene composition having the following composition was mixed in a Henschel mixer and then subjected to twin screw extrusion (Werner
& II°1eiderer, ZSK531
Composition 1 was granulated using > at a resin temperature of 220'C.

[A] Propylene/ethylene block copolymer Nia 5% by weight Ethylene content...25 mol% M F R13g/10min Composition of the above propylene/ethylene block copolymer (I) Propylene polymer component...65 Weight% isotactic index 97 (II) Propylene/ethylene copolymer component...25
mm% Intrinsic viscosity [η]...2,6d, G/g Ethylene content...45 mol% (I [I) Ethylene polymer component...10% by weight Intrinsic viscosity [η]...2 .8dρ/! 7 [B] Ethylene α-
Olefin random co-car body: 15% by weight Ethylene content: 80 mol% MFR: 0.7 g/10 min Crystallinity: 0% Intrinsic viscosity: 2.1 dN/s [C] Talc : 10% by weight Average particle size: 2μ Next, this composition was molded using an injection molding machine (Dynamelter 5J).
-45C1 mold clamping force 14 Q ton, manufactured by 2 Betsu Seisakusho Co., Ltd.) was used to mold the test piece at a resin humidity of 200 °C, and a separate mock bumper mold (length 460
m x width 120 m
I installed a clamping force of 4QQton (manufactured by Nippon A Gosho Co., Ltd.), resin temperature 20o'cm, output pressure 800KFi/c
rA (primary), 500 Kg/cni (secondary), and indexing speed of 24 m/sec.

M F R10y/10 minute flexural modulus (23℃) 9100! JZc Shoulder Izoh Impact tF-Strength (-30°C) -15Kge
cm/cm low temperature embrittlement temperature P] -48
°C surface hardness ([1 Tsukwell R scale)...45
Agent Patent attorney Shunichi Meki vL: ``f city r ``μ4 (spontaneous) 1985/ρ month/Zto 1 1985 patent application No. 99.177q 6. Contents of amendment 1)?! Correct the full text of the range as follows:

"2. Claims 1) A polypropylene composition characterized by having the following composition [A1 propylene/ethylene block copolymer: 98-
55% by weight This propylene/ethylene block copolymer has the following composition, has an ethylene content of 15 to 40 mol%, and a melt flow rate of 5 to 30! J/10 minutes.
(1) Propylene hand coalescence component with isotactic index of 90 or more...50-77 weight percent (rl) ethylene content 20-90 mol%, ultimate clay 1.0-77% (rl)
Propylene/ethylene polymer component necessary for 5.0 dJ7/j...20-35 (II suspension% (1) Ultimate clay is 1.0-10.0 dΩ/J, #4 skewer containing Egulene unit is 90 ~100% ethylene polymer component...3~3otp small% [B] Ethylene α
- Olefin random covalent polymer: O~25,000% This ethylene/α-olefin random covalent polymer has an ethylene content of 5 to 95 mol%, melt flow rate -1-
is 0.1 to 10.0 g/10 min, and the crystallinity by X-ray is 70% or less.

[C] Talc or calcium carbonate: 2-20,000% This talc or calcium carbonate has an average particle size of 0.1-20,000%
It is 5μ. 2) In the third line from the bottom of page 6 of the specification, the phrase ``certain ethylene polymer component'' will be corrected to ``an ethylene polymer component with an ethylene unit content of 90 to 100 mol%''.

3) In lines 9 to 10 of the specification, the phrase ``a certain ethylene polymer component'' has been amended to ``necessarily be an ethylene polymer component containing 90 to 1007% ethylene units.''

Claims (1)

[Scope of Claims] 1) A polypropylene composition characterized by having the following composition [A] Propylene/ethylene block copolymer: 98-
55% by weight This propylene/ethylene block copolymer has the following composition, has an ethylene content of 15 to 40 mol%, and a melt flow rate of 5 to 309/10 minutes. (I) A propylene polymer component with an isotactic index of 90 or more...50 to 77% by weight (II) An ethylene content of 20 to 95 mol% and an intrinsic viscosity of 1.0 to 77% by weight
Propylene/ethylene copolymer component having an intrinsic viscosity of 5.0 dl/g...20 to 35% by weight (III) Ethylene polymer component having an intrinsic viscosity of 1.0 to 10.0 dl/g...3 to 30% by weight % [B] Ethylene/α-olefin random copolymer: 0
~25% by weight This ethylene/α-olefin random copolymer has an ethylene content of 5 to 95 mol%, a melt flow rate of 0.1 to 10.0 g/10 min, and an X-ray crystallinity of 70%. % or less. [C] Talc or calcium carbonate: 2-20% by weight This talc or calcium carbonate has an average particle size of 0.1-20% by weight.
It is 5μ.