Stock material or miscellaneous articles – Structurally defined web or sheet – Including components having same physical characteristic in...
Reexamination Certificate
1998-09-30
2001-03-20
Wilson, Donald R. (Department: 1713)
Stock material or miscellaneous articles
Structurally defined web or sheet
Including components having same physical characteristic in...
C428S516000, C524S427000, C524S435000, C524S442000, C524S449000, C524S451000, C524S505000, C524S528000, C525S088000, C525S240000
Reexamination Certificate
active
06203893
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a propylene resin composition and molded articles thereof which are superior in scratch resistance, moldability, and balance of rigidity and impact resistance; and which are suited for use in electric and electronic parts, packaging materials, engineering plastic substitutes, etc.
Furthermore, the present invention relates to a propylene resin laminate which has, in addition to the above properties, a superior gloss.
2. Background Art
Propylene is widely used, for example, in industrial materials for vehicle parts, electric and electronic parts, etc., and in various packaging materials, since it is generally inexpensive, and has the advantages of light-weight characteristics, mechanical strength, heat resistance, chemical resistance, etc.
In recent years, there has been a strong demand for improvements in quality along with increased functionality and reduced costs for these materials.
In addition, there is the problem that the surface gloss of goods is degraded by heating during secondary molding by means of vacuum forming and the like, and therefore use is limited.
As ways to improve the rigidity, impact resistance, heat resistance, etc., of polypropylene, methods have been proposed such as incorporating an ethylene-propylene rubber and a nucleating agent into an ethylene-propylene block copolymer (Japanese Patent Application, Second Publication, No. Sho 60-3420), and incorporating an ethylene-propylene rubber, an ethylene copolymer, and an inorganic filler into an ethylene-propylene block copolymer (Japanese Patent Application, First Publication, No. Hei 4-275351, Japanese Patent Application, First Publication, No. Hei 5-5051, Japanese Patent Application, First Publication, No. Hei 5-98097, Japanese Patent Application, First Publication, No. Hei 5-98098).
In addition, in order to improve the gloss of secondarily molded articles, a laminate comprising a polyolefin composition layer and a surface layer to which organic or inorganic fillers have been added has been proposed (Japanese Patent Application, First Publication, No. Sho 59-165654).
However, in the above-mentioned methods, although some characteristics have been improved, heat resistance and rigidity still have not been adequately improved. In addition, there is the problem that moldability for vacuum forming and the like is inferior. Furthermore, a satisfactory level for the gloss of secondarily molded articles has not been reached.
SUMMARY OF THE INVENTION
In view of the above, it is a first object of the present invention to provide a propylene resin composition and molded articles thereof which are superior in scratch resistance, moldability, balance of rigidity and impact resistance, etc.
In addition, it is a second object of the present invention to provide a propylene resin laminate having superior gloss in addition to the above properties.
The inventors, through long and careful research, have discovered that the above-mentioned first object can be achieved by a propylene block copolymer having specific properties. The inventors discovered that the above-mentioned second object can be achieved by using the above-mentioned propylene copolymer together with polyolefin. The present invention is based on these discoveries and completely achieves these objects.
More specifically, a first aspect of the present invention provides a propylene resin composition comprising
(A) a composition containing a polypropylene, 45~70 parts by weight, the polypropylene having the following physical characteristics (i) to (iv):
(i) a portion insoluble in xylene at 25° C. by solvent extraction method of not less than 98.0% by weight;
(ii) an isotactic pentad fraction of not less than 96.5%;
(iii) an isotactic average chain length of not less than 90; and
(iv) a total amount of fractions each of which has an isotactic average chain length of not less than 300, according to a column fractionation method, of not less than 10% by weight;
(B) a polyolefin resin, 5~20 parts by weight, the polyolefin having the following physical characteristics (v) to (vii):
(v) a ratio of &eegr;
1
/&eegr;
2
of 4~20, wherein &eegr;
1
is a complex viscosity at a frequency of 10
−1
rad/sec at 190° C., and &eegr;
2
is a complex viscosity at a frequency of 10 rad/sec at 190° C.;
(vi) Tcp of 110~130° C., a ratio of Tmp to Tcp (Tmp/Tcp) of 1.1~1.5, and Tmp/(Tmp-Tcp) of 3.0~9.8, wherein Tcp is crystallization peak temperature, and Tmp is melting peak temperature of the polyolefin resin according to a differential scanning calorimetry (DSC) method; and
(vii) a crystal structure of an a-axis orientation in a diffraction pattern according to an X-ray diffraction method;
(C) at least one inorganic filler selected from the group consisting of precipitated calcium carbonate, hydrated silicic acid, and hydrated calcium silicate, 5~30 parts by weight; and
(D) at least one inorganic filler selected from the group consisting of talc, mica, and potassium titanate, 5~30 parts by weight.
With regard to the above-mentioned first aspect of the present invention, composition (A) containing polypropylene can be a propylene block copolymer comprising
(a) a polypropylene portion, 50~97 parts by weight, having the above-mentioned characteristics (i)~(v); and
(b) a propylene-&agr;-olefin copolymer portion, 3~50 parts by weight, comprising propylene with ethylene and/or an &agr;-olefin olefin of 4~12 carbons which satisfies all of the following conditions:
(viii) an average propylene content (FP) of 20~80% by mole according to a two-site model;
(ix) a propylene content (Pp) of 65~90% by mole in a copolymer (PH) generated at an active site where polymerization of propylene predominantly occurs according to a two-site model;
(x) a proportion of PH in the propylene-&agr;-olefin copolymer of 0.40~0.80; and
(xi) a block property (CSD: Copolymer Sequence Distribution) of 1.8~5.0.
In addition, in place of the above, composition (A) containing polypropylene used in the first aspect of the present invention can be a polypropylene having the above characteristics (i)~(iv). In this case, in addition to the above components (A)~(D), the propylene resin composition contains a rubber polymer (E) 3~15 parts by weight.
In addition, a second aspect of the present invention provides a propylene resin laminate comprising at least two layers: a polypropylene layer (Layer I) made by incorporating a dibenzylidenesorbitol derivative, 0.005~0.5% by weight, in a polypropylene, and a propylene resin composition layer (Layer II) comprising a propylene resin composition of the above-mentioned first aspect of the present invention.
The propylene resin composition of the present invention is superior in scratch resistance, moldability, and balance of rigidity and impact resistance. In addition, the propylene resin laminate of the present invention has, in addition to the above-mentioned properties, superior gloss. Consequently, both the propylene resin composition and the propylene resin laminate of the present invention are particularly useful in automobile parts, electric and electronic parts, packaging materials, etc.
REFERENCES:
patent: 4363885 (1982-12-01), Fukui et al.
patent: 5302653 (1994-04-01), Nishio et al.
patent: 5563194 (1996-10-01), Watanabe et al.
patent: 0265075 (1988-04-01), None
patent: A20462373 (1991-12-01), None
patent: A10538749 (1993-04-01), None
patent: A10651010 (1995-05-01), None
patent: 59-165654 (1984-09-01), None
patent: 60-3420 (1985-01-01), None
patent: 4275351 (1992-09-01), None
patent: 55051 (1993-01-01), None
patent: 598098 (1993-04-01), None
patent: 598097 (1993-04-01), None
“Hawley's Condensed Chemical Dictionary”, 12t ed., Lewis ed., Van Nostrand Reinhold Co., New York p. 1219 (1993).
Billmeyer, “Textbook of Polymer Science”, 2nd ed., Wiley-Interscience, New York, pp. 174-175 (1962).
Nohara Yasuhiro
Watanabe Kazuyuki
Showa Denko K.K.
Sughrue Mion Zinn Macpeak & Seas, PLLC
Wilson Donald R.
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