JPS62158739A - Polypropylene composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent mechanical characteristics such as impact resistance, strength, etc. and surface properties such as surface gloss, etc., consisting of PP, a polyamide and a specified modified polyolefin. CONSTITUTION:30-98pts.wt. PP (A) having a density of 0.89-0.93g/cm<3> and an MFR of 0.01-50g/10min, such as crystalline propylene homopolymer, is blended with 1-69pts.wt. polyamide (B) having a relative viscosity of 0.5 or above (e.g., nylon) and 1-49pts.wt. modified polyolefin (C) obtd. by adding an unsaturated carboxylic acid (derivative) (a) and a reaction initiator (b) (e.g., di-t-butyl peroxide) to a mixture (C) of said PP and a lowly crystalline ethylene/alpha-olefin copolymer having an ethylene content of 20-80wt%, a Mooney viscosity ML1+8 (127 deg.C) of 5-300 and a crystallinity of 35% or below, dry-blending then and melt-kneading them in such a proportion that the combined quantity of the components A, B and C is 100pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a polypropylene composition, and more particularly to a polypropylene composition comprising polypropylene, polyamide and modified polyolefin and having excellent impact resistance and surface properties.

Conventional technology In the past, attempts have been made to improve the physical properties of each resin by blending polypropylene with polyamide.In order to improve the compatibility between polypropylene and polyamide, 1. It is known to add modified polypropylene. However, simply adding this modified polypropylene is not sufficient to improve physical properties such as impact resistance and surface properties.
Proposals have been made to incorporate modified products of low crystallinity or non-uniform polymers with unsaturated carboxylic acid anhydrides. For example, a composition comprising a polyamide and a modified mixture of a crystalline polyolefin and a low-crystalline or non-quality ethylene/α-olefin copolymer (Japanese Unexamined Patent Publication No. 57-824
6), a composition comprising a modified polypropylene, a polyamide, a modified ethylene/a-olefin copolymer with low crystallinity or non-quality properties, and an inorganic filler (Japanese Patent Laid-Open Publication No. 1983-1989)
53550), a Hu synthetic acid product consisting of polypropylene, polyamide and/or polyester, a modified product of a low-crystalline or non-crystalline ethylene/α-olefin copolymer, and an inorganic filler JP-A-60-76548 Public bulletins) etc. have been proposed.

Problems to be Solved by the Invention However, conventional compositions that do not contain polypropylene that is not modified with unsaturated carboxylic acids do not have sufficient mechanical properties such as strength and elastic modulus; Even when a modified product of a crystalline or non-crystalline polymer and a modified polypropylene were mixed together, the compatibility did not improve much and the physical properties were not sufficiently improved.

An object of the present invention is to solve the problems of conventional compositions, to improve the compatibility of a composition comprising polypropylene, polyamide, and modified polyolefin, and to provide a polypropylene composition that has excellent surface properties and mechanical properties. With the goal.

Means for Solving the Problems The present invention provides (A) 30 to 98 parts by weight of polypropylene, (
B) 1 to 69 parts by weight of polyamide and (C) 1 to 49 parts by weight of modified polyolefin obtained by reacting an unsaturated carboxylic acid or a derivative thereof with a mixture of polypropylene and a low-crystalline ethylene/α-olefin copolymer [ however,(
A) 100) + (C) = 100 parts by weight].

The polypropylene in the present invention includes a crystalline propylene homopolymer or propylene and a small amount of ethylene, 1
They are block or random copolymers with α-olefins such as -butene, 4-methyl-1-pentene, and 1-hexene. These polypropylenes have a density α89~
Llqstl Confucian! , MF'Rα is preferably in the range of 01 to 50P/10 minutes.

The polyamide in the present invention refers to acid amide (-cona
-) as a repeating unit, depending on the polymerization method: (]) by ring-opening polymerization of lactam, (2) by polycondensation of aminocarboxylic acid, (3) by polycondensation of diamine and dibasic acid. I can give you things. these are,
Common names for nylon, such as nylon 6, nylon 12, nylon 9, nylon 11, and nylon 66.
, nylon 610, etc., among which nylon 6 and nylon 66 are preferred. Furthermore, although the molecular weight of polyamide is not particularly limited, it is usually determined by the relative viscosity (ηr
81) is α5 or more, preferably 2.0 or more.

In the present invention, the low crystallinity ethylene/α-olefin copolymer includes ethylene and propylene, butene-1,
Be/ten-1, hexene-1,4-methylpentene-1
or a copolymer of ethylene, an α-olefin, and a non-conjugated diene, etc., with an ethylene content of 20 to 80% and a Mooney viscosity of ML1+8 (1
27℃) 5-500, crystallized dust (X-ray diffraction method) 55%
The following low crystallinity or non-crystalline ones are preferred. Suitable examples include rubber-like substances such as ethylene-propylene copolymer, ethylene-butene-1 copolymer, propylene-butene-1 copolymer, and ethylene-propylene-diene copolymer.

The modified polyolefin in the present invention is obtained by reacting an unsaturated carboxylic acid or a derivative thereof with a mixture of the polypropylene and a low-crystalline or non-crystalline ethylene/α-olefin copolymer (hereinafter referred to as low-crystalline polyolefin). 105 to 5 layers have been added. In this case, the blending ratio is preferably 1 to 99 parts by weight of polypropylene, more preferably 30 to 700 to 70 parts by weight, and more preferably 99 to 1 part by weight of crystalline polyolefin, and more preferably 70 to 300 to 30 parts by weight. This mixture contains polyolefins other than polypropylene, such as polyethylene of various densities, polybutene-1, crystalline ethylene-
An α-olefin copolymer or the like may be added in an amount of 30% by weight or less into the mixture.

Examples of unsaturated carboxylic acids or derivatives thereof include acrylic acid, maleic acid, 7maric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, endobicyclo-[su2,1]-5- Examples include heptene-2,5-dicarboxylic acid, acid anhydrides thereof, and esters.

The method for producing modified polyolefin in the present invention includes:
Various known methods can be employed. For example, polypropylene and low crystalline polyolefin are combined with unsaturated carboxylic acids or derivatives thereof and reaction initiators such as di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t
- A method of adding an organic peroxide such as (butylperoxy)-hexyne-3, pre-triblending and melt-kneading,
Alternatively, a preferred method is to dissolve a mixture of polypropylene and low-crystalline polyolefin in a solvent, add an unsaturated carboxylic acid or a derivative thereof, and a reaction initiator, and react.

As mentioned above, the addition of a modified product obtained by simultaneously reacting an unsaturated carboxylic acid or its derivative to a mixture of polypropylene and a low-crystalline polyolefin improves the compatibility with polypropylene and polyamide in melt mixing, and The polyamide can be more finely dispersed in the matrix.

Next, the polypropylene composition of the present invention comprises (A) 30 to 98 parts by weight of polypropylene, preferably 40 to 90 parts by weight, and 1 to 69 parts by weight of polyamide, preferably 5 to 5 parts by weight.
5 parts by weight and (C) modified polyolefin 1 to 49 parts by weight, preferably 5 to 40 parts by weight [However, C) + (B) + (
C)=1o weight is part]. If the blending amount of polyamide is less than the above, the physical properties of polypropylene will not be improved due to the properties of the polyamide, while if the blending amount exceeds the blending amount, the rigidity etc. will be reduced due to the hygroscopicity of the polyamide, so the physical properties will not be improved. If the amount of the modified polyolefin is less than the above range, the compatibility of the composition, which is the object of the present invention, will not be improved and the impact resistance and surface properties will not be improved.

On the other hand, when the blending amount exceeds the above range, rigidity, heat resistance, oil resistance, surface hardness, etc. are significantly reduced.

The composition of the present invention can be produced by mixing the above-mentioned (A) polypropylene, ω) polyamide, and (C) modified polyolefin in the above-mentioned amounts. for example,
The above ingredients are mixed in advance using a Henschel mixer, ribbon blender, etc., and this mixture is mixed using a Banbury mixer.
It is preferable to melt and knead the mixture using a roll, extruder, etc., and then pelletize or crush the mixture. In addition, when melt-mixing the composition, since the melt viscosity of polyamide is generally lower than that of polypropylene and modified polyolefin, in order to further improve the dispersibility of the composition, it is necessary to melt-knead the polyamide and modified polyolefin in advance. It is desirable to increase the melt viscosity before melt kneading with polypropylene.

The composition of the present invention may contain heat stabilizers, ultraviolet absorbers, nucleating agents, antistatic agents, lubricants, flame retardants, colorants, non-fillers, plasticizers, etc. within the range that does not impair the purpose of the present invention. It's okay. These additives may be added during or after preparing the composition.

Next, the present invention will be explained in detail by giving examples. In addition,
All sections and sections in the Examples are based on cast bones, and the test method is as follows.

(]) M F R: : rxs K 7210 (Load 2.16 kg, 230°C) (2) Tensile strength, tensile elongation at break: A8TM D 63
8(3) Bending strength, bending modulus: A8TM D 79
0 (41 Izot impact strength: A8TM D 256
(23℃) (5) Glossiness (cloth): A8TM
D 523 homopolypropylene (MFR=5.0) (
! : Ethylene-propylene copolymer [manufactured by Japan Synthetic Rubber Co., Ltd. 1, ysREPO7F (trade name), ethylene-containing 73
%, Mooney viscosity ML1+4 (100°C) 70, hereinafter referred to as EPR], ethylene-butene-1 copolymer [manufactured by Mitsui Petrochemicals, Tafmer A4085 (trade name), Mooney viscosity ML1+4 (100°C) 60, hereinafter referred to as HBR ], Ethylene-propylene-diene copolymer [manufactured by Exxon Chemical Co., Ltd., VI8TALON 37081 (trade name), Mooney viscosity ML1+8 (127°C) 5 hours or less K
PDM] and linear low-density polyethylene [manufactured by Nippon Unicar Co., Ltd., NLC5391 (trade name), hereinafter LLC) P
K] in the proportions shown in Table 1, and this mixture 1
For 00 parts, engineering/tobicyclo-[2,2,1]-5-
After adding 13 parts of hebutene-2,3 dicarbonic anhydride and 3 parts of a reaction initiator [2,5-dimethyl-2,5-di(t-butylperoxy)-hexyne-3] α, and pre-triblending. , 65 rhymes φ with 225CK set, b/n=
Supply the resin to a za vented single-screw extruder at a resin temperature of 230°C.
Each modified polyolefin was obtained by melt-kneading. Table 1 shows the amount of acid added to the modified polyolefin.

Table 1 Manufacture of polypropylene composition Homopolypropylene (MiFR=5), nylon 6 (
ηre1=2-5) and the above-mentioned modified polyolefin were blended in the ratio shown in Table 2, triblended in advance, and then coaxial twin-shaft kneading extrusion with a vent of 45■φ set at 250C and L/D=30. The mixture was fed into a machine and melted and kneaded to form pellets.

The obtained pellets were injection molded at 230°C to form test pieces for measuring physical properties, and the physical properties were measured. The measurement results are shown in Table-2.

Comparative Examples 1 to 6 Single modified products of the above-mentioned PP and EPH (hereinafter referred to as cMpp)
, cMxpR) (Comparative Example 1.2)
The same procedure as in the example was carried out for cases in which the modified PF and modified EPR were combined (Comparative Examples 3 and 4), and when only polyamide was blended into the modified mixture of pp and KPH (Comparative Example 5.6). The composition was manufactured and a test piece was molded to measure the physical properties. The measurement results are shown in Table 3.

In addition, when the cross sections of the compositions of Example 1 and Comparative Example 3 were extruded with formic acid and the nylon 6 phase was eluted, observation using a scanning micrograph showed that the nylon 6 of Example 1 was the same as that of Comparative Example 3.
It was observed that the size of the dispersed phase was finer and more uniformly dispersed than that of the conventional method.

Effects of the Invention The composition of the present invention has improved compatibility between polypropylene and polyamide compared to conventional compositions, and the polyamide is more finely dispersed in the polypropylene matrix. In addition, in combination with the content of the modified low-crystalline polyolefin, mechanical properties such as strength and impact resistance, and surface properties such as surface gloss are improved.

Due to the above properties, the composition of the present invention is suitable for various industrial materials, particularly automobile parts, household appliance parts, and the like.

Claims (1)

Scope of Claims: (A) 30 to 98 parts by weight of polypropylene, (B) 1 to 69 parts by weight of polyamide, and (C) a mixture of polypropylene and a low-crystalline ethylene/α-olefin copolymer containing unsaturated carbon 1 to 49 parts by weight of a modified polyolefin prepared by reacting an acid or a derivative thereof [However, (A) + (B
)+(C)=100 parts by weight].