JP2004075963A - Polypropylene alloy improved in scratch-proofness and impact resistance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy impact resistance and scratch-proofness which are required for an interior material of an automobile, simultaneously. <P>SOLUTION: This polypropylene alloy is obtained by using an HDPE excellent in scratch-proofness as an additive material with a PP parent material, adding an SEBS (styrene-ethylene-butadiene-styrene block copolymer) or SEBC (styrene-ethylene-buladiene-olefin crystalline block copolymer) as an intermediate material of the PP and HDPE and effecting the HDPE as a toughener i.e. rubber for increasing impact strength. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to automotive interior materials, and more particularly, to improving the functions of dashboards and door trims of automobiles.
[0002]
[Prior art]
For dashboard and door trim materials, 15% to 30% of talc is added to PP to secure rigidity, and 10% to 20% of rubber such as EPM, EBM and EOM is added to improve impact strength. Is known.
[0003]
[Problems to be solved by the invention]
Polypropylene, which is a raw material of the material described in the prior art, has a problem that it is hard but easily scratched and easily broken.
[0004]
Also, if rubber is added to prevent cracking, the material becomes soft, so talc was added to prevent it and further secure rigidity, but while the material became harder, the fragility also increased, and the scratch resistance was increased. It had the problem of getting worse.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to improve both the scratch resistance of a material and its impact strength.
[Means for Solving the Problems]
In order to achieve the above object, the HDPE added in the present invention reduces the kinetic friction coefficient of the material, thereby improving the scratch resistance, and is finely dispersed by the action of the added SEBS or SEBC, and at the same time, the impact strength of the material. [0007]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the invention will be described with reference to the drawings.
FIG. 1 is a structural diagram of PP, SEBS and HDPE based on the alloy morphology. In the case of SEBC, the basic function is the same, except that one domain of polystyrene is replaced with a domain of an olefin crystal.
[0008]
HDPE domain 2 is finely dispersed and floating in the sea of the PP1 matrix due to the compatibilizing action of SEBS or SEBC. At that time, the SEBS forms the polystyrene domain 3 around the HDPE domain 2, and its EB chain 5 bites into the HDPE domain 2 while being entangled with the PP chain 4.
[0009]
SEBS acts to strongly link the two between PP1 and HDPE domain 2. Even when an impact is applied, it acts as an intermediate elastic material and expands to make it difficult to crack the material.
[0010]
It is generally known that HDPE itself has a low coefficient of kinetic friction and is excellent in scratch resistance. In addition, silicon or HDPE is added to PP to reduce the coefficient of kinetic friction of PP due to its characteristics, thereby improving scratch resistance. Improving is also generally known. In addition, as a countermeasure against scratching, it is generally practiced to add 5% or more by weight of PP to PP in the case of HDPE.
[0011]
Even if HDPE is finely dispersed in SEBS or SEBC to become HDPE domain 2, the molecular structure itself does not change, so that its characteristics are maintained. Therefore, HDPE domain 2 also lowers the kinetic friction coefficient of PP1 and has the same effect on scratch resistance.
[0012]
【The invention's effect】
Since the present invention is configured and functions as described above, it has the following effects.
[0013]
It is an interior material with the same rigidity as before, but has impact resistance and also has scratch resistance.
[0014]
The dashboard and door trim of an automobile can be formed by injection molding in the same manner as conventional materials.
[Brief description of the drawings]
FIG. 1 is a structural diagram of PP, HDPE, and SEBS alloys.
[Explanation of symbols]
1 PP
2 HDPE domain 3 Polystyrene domain 4 PP chain 5 EB chain

Claims (1)

PP 56% to 77%
SEBS or SEBC 3-8%
HDPE 5-10%
Talc 15-26%
Is PP alloy, PP is polypropylene.
SEBS and SEBC are both block copolymers of hydrogenated styrene butadiene, SEBS is a styrene ethylene butadiene styrene block copolymer, and SEBC is a styrene ethylene butadiene olefin crystal block copolymer. HDPE is high density polyethylene.

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