Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-08-17
2001-11-20
Woodward, Ana (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C523S212000, C524S492000, C524S493000, C524S495000, C525S066000, C525S09200D, C525S101000
Reexamination Certificate
active
06319976
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to compositions comprising a polyamide resin, a broad molecular weight distribution propylene polymer material, and a graft copolymer of a propylene polymer material.
BACKGROUND OF THE INVENTION
Blends of two or more polymers have often been made, for example in attempts to combine desirable properties of the individual polymers into the blend, to seek unique properties in the blend, or to produce less costly polymer products by including less expensive polymers in the blend. Many attempts have been made to blend polyamide resins, such as nylon-6 and nylon-6,6, and polyolefin materials. Polyamide resins have excellent chemical and abrasion resistance, good oxygen barrier properties, good electrical properties, and superior mechanical strength, but are very moisture sensitive and are difficult to process due to their high melting temperature. Polypropylene is a low cost, low density semi-crystalline polymer with excellent moisture resistance that is capable of being recycled and is easy to process.
However, it is difficult to obtain a good dispersion of a polar polyamide resin and a nonpolar polyolefin resin. It is known that the addition of a graft or block copolymer of similar chemical structure to the blend components can improve the quality of the dispersion. These copolymer additives, generally referred to as compatibilizers, are often added to the blend as a third component.
Maleic anhydride-grafted polypropylene has been used as a compatiliblizer for polypropylene
ylon blends. For example, a graft copolymer that is the reaction product of a styrene/maleic anhydride copolymer and a functionalized thermoplastic polymer, such as polypropylene grafted with carboxylic acid-containing monomers, is added to a polyamide and, optionally, polypropylene, as disclosed in U.S. Pat. No. 5,244,971. The styrene copolymer can be based on styrene and/or alpha-methylstyrene and maleic anhydride and optionally an acrylate or methacrylate and/or acrylonitrile. U.S. Pat. No. 5,317,059 discloses a polymer composition comprising (1) at least one olefin polymer, (2) at least one polyamide, (3) a compatibilizing agent that is at least one terpolymer of an alpha-olefin, an acrylic ester, and an unsaturated dicarboxylic acid reagent or a glycidyl acrylate, and optionally (4) an auxilliary compatibilizing agent. U.S. Pat. No. 5,665,820 discloses the use of an elastomeric polypropylene modified with an unsaturated grafting monomer and/or blends thereof with isotactic polypropylene modified with an unsaturated grafting monomer as a compatibilizer for a blend of a polyamide and a polyolefin. The grafting monomers used include unsaturated mono-or dicarboxylic acids or anhydrides or esters thereof, esters of vinyl alcohol, vinyl aromatic compounds, and mixtures thereof. U.S. Pat. No. 5,234,993 discloses a blend of at least one polyamide and a crystalline polyolefin containing a compatibilizing rubbery polymer such as an ethylene/propylene/diene rubber grafted with at least one of maleic anhydride and glycidyl methacrylate.
However, there is still a need for a material that will produce a homogeneous polyamide/polyolefin blend with improved impact resistance and an improved balance of strength and stiffness.
SUMMARY OF THE INVENTION
The composition of this invention comprises, by weight,
(1) about 1% to about 98% of a graft copolymer comprising a backbone of a propylene polymer material having graft polymerized thereto monomers selected from the group consisting of (a) at least one vinyl aromatic compound and an unsaturated carboxylic acid and (b) at least one vinyl aromatic compound and an anhydride of an unsaturated carboxylic acid or its acid form, wherein the polymerized monomers are present in an amount of about 10 to about 95 parts per hundred parts of the propylene polymer material, and
(2) about 99% to about 2% of at least one polyamide resin
“(3) about 5% to about 90% of a broad molecular weight distribution propylene polymer material having a weight average molecular weight to number average molecular weight ratio of about 5 to about 60;
(4) optionally, about 2% to about 30% of at least one rubber component selected from the group consisting of (i) an olefin copolymer rubber, (ii) a monoalkenyl aromatic hydrocarbon-conjugated diene block copolymer, and (iii) a core-shell rubber; and
(5) optionally, an additive to improve the scratch and mar resistance of the composition selected from the group consisting of (a) about 0.5% to about 10% of at least one low molecular weight ethylene polymer of a functionalized derivative thereof, having a number average molecular weight of about 300 to about 5000, and (b) a combination of about 0.5% to about 10% of at least one of the low molecular weight ethylene polymers in (a) and about 0.5% to about 10% of inorganic microspheres.”
Blends of the graft copolymer and a polyamide are compatible, are easy to process, and have good moisture barrier properties. Articles produced from these blends have good impact resistance and a good balance of strength and stiffness.
DETAILED DESCRIPTION OF THE INVENTION
The amount of graft copolymer in the composition of this invention is about 1% to about 98%, preferably about 50% to about 90%, based on the total weight of the composition.
The propylene polymer material that is used as the backbone of the graft copolymer can be:
(1) a homopolymer of propylene having an isotactic index greater than 80, preferably about 85 to about 99;
(2) a copolymer of propylene and an olefin selected from the group consisting of ethylene and 4-10 C alpha-olefins, provided that when the olefin is ethylene, the maximum polymerized ethylene content is about 10%, preferably about 4%, and when the olefin is a 4-10 C alpha-olefin, the maximum polymerized content thereof is about 20% by weight, preferably about 16%, the copolymer having an isotactic index greater than 85;
(3) a terpolymer of propylene and two olefins selected from the group consisting of ethylene and 4-8 C alpha-olefins, provided that the maximum polymerized 4-8 C alpha-olefin content is 20% by weight, preferably about 16%, and, when ethylene is one of the olefins, the maximum polymerized ethylene content is 5% by weight, preferably about 4%, the terpolymer having an isotactic index greater than 85;
(4) an olefin polymer composition comprising:
(a) about 10% to about 60% by weight, preferably about 15% to about 55%, of a propylene homopolymer having an isotactic index greater than 80, preferably about 85 to about 98, or a copolymer of monomers selected from the group consisting of (i) propylene and ethylene, (ii) propylene, ethylene and a 4-8 C alpha-olefin, and (iii) propylene and a 4-8 C alpha-olefin, the copolymer having a polymerized propylene content of more than 85% by weight, preferably about 90% to about 99%, and an isotactic index greater than 85;
(b) about 5% to about 25% by weight, preferably about 5% to about 20%, of a copolymer of ethylene and propylene or a 4-8 C alpha-olefin that is insoluble in xylene at ambient temperature; and
(c) about 30% to about 70% by weight, preferably about 40% to about 65%, of an elastomeric copolymer of monomers selected from the group consisting of (i) ethylene and propylene, (ii) ethylene, propylene, and a 4-8 C alpha-olefin, and (iii) ethylene and a 4-8 C alpha-olefin, the copolymer optionally containing about 0.5% to about 10% by weight of a polymerized diene and containing less than 70% by weight, preferably about 10% to about 60%, most preferably about 12% to about 55%, of polymerized ethylene and being soluble in xylene at ambient temperature and having an intrinsic viscosity, measured in tetrahydronaphthalene at 135° C., of about 1.5 to about 4.0 dl/g,
wherein the total amount of (b) and (c), based on the total olefin polymer composition, is about 50% to about 90%, the weight ratio of (b)/(c) is less than 0.4, preferably 0.1 to 0.3, and the composition is prepared by polymerization in at least two stages and has a flexural modulus of less than 150 MPa; or
(5) a thermoplastic olefin compri
DeNicola, Jr. Anthony J.
Phan Tam T. M.
Montell Property Company BV
Woodward Ana
LandOfFree
Polyolefin graft copolymer/polymide blend does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polyolefin graft copolymer/polymide blend, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polyolefin graft copolymer/polymide blend will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2590352