JPS6086153A - Impact-resistant polypropylene composition - Google Patents

Abstract

PURPOSE:To provide a composition having extremely high impact resistance, and composed of an OH-containing compound and a grafted product obtained by grafting an alpha,beta-unsaturated carboxylic acid to a mixture of an isotactic polypropylene and an ethylene.alpha-olefin rubber. CONSTITUTION:(A) 100pts.wt. of a grafted product obtained by grafting an alpha,beta- unsaturated carboxylic acid or its derivative to a mixture of (i) an isotactic polypropylene and (ii) an ethylene-alpha-olefin random copolymer having an alpha-olefin content of 25-60wt% (the weight ratio of i:ii is 90:10-70:30) is compounded with (B) 1-35pts.wt. of a compound having two or more hydroxyl groups in the molecule. The alpha-olefin in the component A is preferably butene-1, etc., and the unsaturated carboxylic acid is preferably maleic acid. The component B is e.g. ethylene glycol, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to impact-resistant polypropylene compositions, and more particularly, the present invention relates to impact-resistant polypropylene compositions, and more particularly, a mixture of Aitutakuti Ink polypropylene and ethylene-α-olefin rubber is combined with an α,β-unsaturated carboxylic acid or a derivative thereof. to the grafted product grafted with
- It relates to a polypropylene composition having extremely excellent impact resistance, which is made by blending an organic compound having two or more hydroxyl groups in the molecule.

Prior art Tactical polypropylene is inexpensive and has excellent mechanical properties, transparency, heat resistance, surface gloss, chemical resistance, acid resistance, and alkali resistance, and is also suitable for injection molding, blow molding, and various types of films. Since it is easy to mold by various molding methods such as molding, it is used in large quantities in a very wide range of applications, but it has the disadvantage of low impact resistance compared to polyethylene and the like.

As a method for improving the impact resistance of such tactical polypropylene, polypropylene is injected with ethylene/propylene rubber (EPR), EPR and polyethylene (P
The method of mixing E) is generally well known. Methods for mixing EPR and PE with polypropylene include a method in which a two-stage or three-stage glue actor is used in a polymerization system, and a method in which mechanical post-blending is performed using a kneader or the like. The mixtures (or block copolymers) of polypropylene and EPR or of polypropylene and BPR and PE thus obtained, known as HIPP, have a certain The impact resistance is improved by about 2 to 4 times. However, the absolute value of impact resistance is at most 5 to 9 kg-cm/(JA) in terms of Izotsu impact strength, and extremely high impact resistance is required for automobile bumpers, auto-high fenders, helmets, etc. However, it is still insufficient for many applications.

OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide polypropylene compositions that are more impact resistant than those currently known as high impact polypropylenes (HIPP).

Structure of the Invention The 11-shot resistant polypropylene composition according to the present invention comprises (
i) Tactical polypropylene and (ii)
Ethylene-α with α-olefin content of 15-60% by weight
-Ethylene composed of olefin random copolymer-α-
(i):(ii) with olefin rubber =90:10
A grafted product (A
) 1 to 35 parts by weight of an organic compound (B) having two or more hydroxyl groups in the molecule is blended with 100 parts by weight.

Detailed Description of the Structure and Effects of the Invention According to the present invention, as described above, a grafted product obtained by grafting α, β-unsaturated carboxylic acid, etc. onto a mixture of Aitu Takuti Ink polypropylene and ethylene-α-olefin rubber is used. By blending with an organic compound having two or more hydroxyl groups in one molecule, a polypropylene composition has extremely high impact resistance with an Izot impact strength of 30 to 7 Q kg-cm/cJ, as explained below. It can be suitably used in applications that require extremely high impact resistance, such as automobile bumpers, motorcycle fenders, and helmets.

The isotaft polypropylene used in the present invention includes a propylene homopolymer and a copolymer of propylene and a small amount of α-olefin. Polymerization is carried out by slurry polymerization using a low-volatility poor solvent or propylene monomer that does not dissolve in the solvent, or by gas phase polymerization without using a solvent.

The above copolymer of propylene and α-olefin is α
- Random copolymers with an olefin content of 5% by weight or less are preferred. The α-olefin content of the random copolymer is 5
Exceeding this percentage by weight is not preferable because the rigidity decreases.

α-olefin content used in the present invention: 25-60
Examples of the α-olefin in the ethylene-α-olefin random copolymer rubber in weight percent include propylene, butene-1, hexene-1, etc., and if necessary, tertiary
Polymerization is carried out by adding a diene such as hexadiene or ethylidene norbornene as a component, using a Ziegler catalyst or a vanazine catalyst, and using a solution method, slurry method, or gas phase method.

According to the present invention, (i) isotaft polypropylene and (ii) ethylene-α-olefin copolymer rubber have a weight ratio of (i): (ii) = 9010.
They are mixed in a ratio of ~70:30. Such mixing is carried out, for example, by polymerizing isotafty polypropylene and then copolymerizing it with an α-olefin such as ethylene or butene-1 in a polymerization reactor. (This may be done by different methods, or by mixing the separately polymerized products using a general extruder or kneader).

If the mixing ratio of the ethylene-α-olefin copolymer is less than the above ratio, the impact resistance will be insufficient; on the other hand, if it is higher, the impact resistance will be good, but the strength and rigidity will decrease. So I don't like it.

According to the invention, the above mixture is prepared by adding α,β-unsaturated carboxylic acids or derivatives thereof (e.g. acrylic acid to meccrylic acid,
fumaric acid, itaconic acid, immitsic acid, maleic acid or its anhydride, etc., maleic anhydride is preferred)
Graft with. The amount of α, β-unsaturated carboxylic acid, etc. grafted onto the mixture of organic polypropylene and ethylene-α-olefin copolymer rubber is the grafted product m! 0.1 to 5% by weight, preferably 0.2 to 5% by weight per
It is 1% by weight. If the grafting amount of α, β-unsaturated carboxylic acid, etc. is less than 0.1% by weight, the desired effect of improving impact resistance will not be observed, and if it exceeds 5% by weight, there will be no particular problem, but impact resistance This is not preferred because no further sex-improving effect is observed and it is not economical.

The method of grafting α,β-unsaturated carboxylic acid, etc. to the mixture is carried out, for example, as follows.

Radical generators used for graft modification include dicumyl peroxide, penzoyl peroxide, di-t-
Organic peroxides such as butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, lauroyl peroxide, and t-butyl peroxyhenzoate are preferably used, and two or more A combination is also possible.

As a graft modification method, a polyolefin suspended or dissolved in a suitable solvent is used.1. A method of adding a graft monomer and a radical generator to a polyolefin and stirring with heating; a method of mixing a polyolefin, a graft monomer and a radical generator in advance, and then melt-kneading the mixture using an extruder, Banbury mixer, kneader, etc. However, the latter method is generally simpler. Note that the amounts of the radical generator and graft monomer used for radical modification are not particularly limited, but 0.001 to 0.5 parts by weight of the radical generator, α, β-unsaturated, per 100 parts by weight of the polyolefin. 0.1 to 10 parts by weight of carboxylic acid or derivative thereof.

According to the present invention, the grafted product is mixed with an organic compound having two or more hydroxyl groups in one molecule. Such organic compounds include, for example, the general formula HO-R-OH (
R is a saturated or unsaturated aliphatic hydrocarbon group or an alicyclic hydrocarbon group, an aromatic hydrocarbon group, an aromatic hydrocarbon group containing a saturated or unsaturated aliphatic or alicyclic hydrocarbon group, or the above-mentioned hydrocarbon group; This refers to a group substituted with a functional group such as amine, carboxyl, ester, thiol, or alcohol, or a halogen atom such as chlorine, fluorine, or bromine. ) As long as R has the above structure, the HO-R-OH compound may be a low molecular compound, a high molecular compound, or a modified polymer.

Specific examples of compounds containing two or more hydroxyl groups used in the present invention include ethylene glycol, propylene glycol, compounds in which CH2(OH)-CHz□-OH groups are bonded, and hydrolysis of ethylene-vinyl acetate copolymers. Examples include polyvinyl alcohol, polyvinyl alcohol, and modified products thereof.

A mixture of the grafted product and an organic compound having 2 (11iI or more hydroxyl groups in one molecule) can be carried out by any general mixing method, for example, by using a Banbury mixer, a kneader, or an extruder. The two can be mixed under conditions in which they are molten, or both can be dissolved and mixed in a solvent such as toluene or xylene, but the former is generally preferred.

The organic compound is added in an amount of 1 to 100 parts by weight of the grafted product.
35 parts by weight, preferably 5 to 15 parts by weight. If the amount of the organic compound is less than 1 part by weight, the effect of improving impact resistance will not be sufficient, and if it exceeds 35 parts by weight, the rigidity, strength, fluidity, etc. of the polypropylene will be significantly changed, which is not preferable. .

The mechanism by which the impact resistance of the polypropylene composition according to the present invention is significantly improved is not clear, but in conventional high impact polypropylene (HIPP), the rubber component (EPR) with impact absorption effect is continuous with polypropylene. In the polypropylene composition according to the present invention, α, β-unsaturated carboxylic acids, etc. bonded to the polypropylene dispersion and the ethylene-α-olefin copolymer rubber molecules, whereas they were simply dispersed in the phase. - The hydroxyl group of an organic compound having a hydroxyl group of 2 + This is thought to be due to the increased affinity and bonding strength of the interface (ester bonds are actually confirmed in the infrared absorption spectrum).

EXAMPLES The present invention will be described in detail below, but it goes without saying that the scope of the present invention is not limited to these Examples. In addition, in the examples, "%" and "parts" respectively indicate "% by weight" and "parts by weight" unless otherwise specified. The physical properties were measured using the following method.

MFI: Measured at 230°C according to JrS-'6758.

Shore D: ASTM-1)-2240 Izot impact strength: Measured at 25°C according to JIS-6758 (
kg・cm/cl).

Tensile strength: Measured according to JIS-6758. Tactical ink made of 80% polypropylene and polypropylene 7
Peroxide (dicumyl peroxide 0 .IP
0.35% of maleic anhydride was grafted in an extruder using 0.5P HR of maleic anhydride. This grafted product was used as component A, while an ethylene-vinyl acetate copolymer with a vinyl acetate content of 33% and Ml (measured at 190°C according to Jls-6730) of 92.5 (g/10 min) was An ethylene/vinyl acetate/vinyl alcohol copolymer obtained by hydrolysis at a conversion rate of 93% was used as the B component, and 97 parts of the A component and 3 parts of the B component.
The mixture was blended for 5 minutes at a temperature of 200°C using a laboplasto mill.

The physical properties of the grafted product (blank) before blending and the polypropylene composition after blending (Example 1) were measured, and the obtained results are shown in Table 1.

As is clear from the results in Table 1, the Izot impact strength of the blank was 6.5 kg-cm/c-, while the Izot i41 impact strength of the obtained polypropylene composition of Example 1 was 35.6. kg-can/co!
A significant improvement in impact resistance was observed.

Examples 2 to 6 The maleic anhydride grafted product obtained in Example 1 was used as the A component, and the various ethylene/vinyl acetate/vinyl alcohol copolymers shown in Table 1 were used as the B component to convert the A and B components. A polypropylene composition was obtained by blending in the same manner as in Example 1 in the proportions shown in Table 1.

The physical properties of the obtained composition were measured in the same manner as in the example, and the results are shown in Table 1.

Mll (measured at 230°C) consisting of 82% polypropylene and 18% ethylene-propylene random copolymer rubber with a propylene content of 48% (measured at 230°C) with the following margins 10.0
(g/10 min) of polypropylene mixture and 0,2 P HR,, MA of dicumyl peroxide dicanop.
Maleic anhydride (MAR>1.0%) was grafted by a mixed reaction in a kneader using H2P HR, while Example 1
Using the same ethylene/vinyl acetate/vinyl alcohol copolymer as the B component, 97 parts of the A component and 3 parts of the B component were blended for 5 minutes at a temperature of 2°C using a Laboplastomill.

The physical properties of the grafted product (blank) before blending and the polypropylene composition after blending (Example 7) were measured in the same manner as in Example 1, and the obtained results are shown in Table 2.

As is clear from the results in Table 2, blank job-I
] was 5.2, whereas the Shore D value of the obtained polypropylene composition of Example 7 was 40, indicating a significant improvement in hardness.

Examples 8 to 11 Using the same B component as in Example 7, the MFI, rubber compounding amount, and maleic anhydride bonding amount of the polypropylene mixture of A component were changed as shown in Table 2, or the A component and B component were Polypropylene compositions were obtained by varying the blend ratio of.

The physical properties of the resulting composition were measured in the same manner as in Example 1, and the results are shown in Table 2.

Below are blank examples 12 and 13. MF16.2 (230°C, g/
10 minutes) was grafted in the same manner as in Example 1 to obtain a grafted product with a maleic anhydride bond content of 0.53%. Using this grafted product as the A component, the third
A blend was made in the same manner as in Example 1 using the polyethylene glycol shown in the table as the B component.

The physical properties of the obtained polypropylene composition were measured in the same manner as in Example 1, and the results are shown in Table 3.

Below margin

Claims (1)

[Claims] 1. (i) Tactical polypropylene; (i)
i) Ethylene with an α-olefin content of 25-60% by weight
Ethylene-α composed of α-olefin random copolymer
-(i):(ii) with olefin rubber =90:1
0 to 7'O: 30 (weight ratio) to 100 parts by weight of the grafted product (A) obtained by grafting α, β-unsaturated carboxylic acid or its derivative, -2 hydroxyl groups in the molecule.
(An impact-resistant polypropylene composition comprising 1 to 35 parts by weight of a compound (B) having lI+1 or more.