Method of improving scratch resistance and related products and uses

1. A process for improving the scratch resistance of a rubber modified polymer, which process comprises mixing

polytetrafluoroethylene as a friction reducing agent,

a grafted polymer,

an unsaturated fatty acid amide,

a filler, and

optionally, one or more further additives,

with a rubber modified polymer,

in respective amounts to obtain a composition comprising

20 to 98 weight % of the rubber modified polymer,

0.2 to 40 weight % of the grafted polymer,

0.1 to 10 weight % of the friction reducing agent,

0.1 to 1 weight % of the unsaturated fatty acid amide, and

5 to 40 weight % of the filler,

optionally 0.01 to 5 weight % of the one or more further additives,

wherein the grafted polymer has a backbone selected from the group consisting of polypropylene, polyisobutylene, polyethylene, mixtures of polypropylene with polyisobutylene, mixtures of polypropylene with polyethylene, mixtures of different types of polyethylene, ethylene/propylene copolymers, propylene/but-1-ene copolymers, propylene/isobutylene copolymers, ethylene/but-1-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethylene-/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers, polymers of ethylene with propylene and hexadiene, polymers of ethylene with propylene and dicyclopentadiene, polymers of ethylene with propylene and ethylidene-norbornene, polystyrene, acrylonitrile-butadiene-styrene polymers, styrene-butadiene-styrene triblock copolymers, styrene-acrylonitrile copolymers, acrylonitrile-acrylate elastomer-styrene copolymers, ethylene-propylene-diene copolymers, copolymers of ethylene with higher alpha-olefins, polybutadiene, polyisoprene, styrene-butadiene copolymers, hydrogenated styrene-butadiene copolymers, styrene-isoprene copolymers and hydrogenated styrene-isoprene copolymers; wherein the backbones are grafted with an unsaturated carboxylic acid monomer selected from the group consisting of acrylic acid, methacrylic acid, cyanoacrylic acid, maleic acid, 2-methyl maleic acid, 2-ethyl-maleic acid, 2-phenyl-maleic acid, 2,3-dimethyl maleic acid, fumaric acid and mixtures thereof; or with an anhydride or an ester of said monomers; or with a vinyl aromatic compound; or with two or more monomers selected from the group consisting of said unsaturated carboxylic acid monomers, esters thereof and the vinyl aromatic compound; and

wherein the rubber modified polymer is a mixture of a polymer and a rubber-like component, where the polymer is a polypropylene, a styrene comprising polymer, a polyester, a polyamide, a copolyether amide, a copolyester amide, a thermoplastic elastomer on urethane basis, a polycarbonate, a polycarbonate/acrylonitrile-butadiene-styrene blend, an acrylonitrile-butadiene-styrene/poly(butylenes terephthalate) blend, poly(vinyl chloride), poly(vinyl chloride)/acrylonitrile-butadiene-styrene blend, poly(vinyl chloride)/acrylonitrile-strene-acrylate blend, acrylate-modified poly(vinyl chloride) or an ionomer; and

the rubber-like component is an ethylene-α-olefin copolymer rubber, an ethylene-α-olefin-non-conjugated diene copolymer, natural rubber, isobutene rubber, butadiene rubber, polyisoprene, 1,2-polybutadiene, styrene-butadiene random copolymer rubber, chloroprene rubber, nitrile rubber, styrene-isoprene copolymer, styrene-isoprene-styrene block copolymer rubber, ethylvinyl-acetate copolymer, hydrogenated styrene-butadiene copolymers, hydrogenated styrene-isoprene copolymers or mixtures of two or more thereof.

2. A process according to claim 1 , wherein the grafted polymer is a grafted polyethylene that has a backbone selected from the group consisting of polyethylene, mixtures of different types of polyethylene, ethylene/propylene copolymers, ethylene/but-1-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers, polymers of ethylene with propylene and hexadiene, polymers of ethylene with propylene and dicyclopentadiene and polymers of ethylene with propylene and ethylidene-norbornene;

wherein the backbones are grafted with an unsaturated carboxylic acid monomer selected from the group consisting of acrylic acid, methacrylic acid, cyanoacrylic acid, maleic acid, 2 methyl maleic acid, 2-ethyl-maleic acid, 2-phenyl-maleic acid, 2,3-dimethyl maleic acid, fumaric acid and mixtures thereof; or with an anhydride or an ester of said monomers; or with a vinyl aromatic compound; or with two or more monomers selected from the group consisting of said unsaturated carboxylic acid monomers, esters thereof and the vinyl aromatic compound.

3. A process according to claim 1 , wherein the unsaturated fatty acid amide is of the formula R—C(O)—NHR*,

wherein R is an unsaturated alkyl group having from 10 carbon atoms to 26 carbon atoms and R* is an unsaturated alkyl group having from 10 to 26 carbon atoms or hydrogen.

4. A process according to claim 1 , wherein the unsaturated fatty acid amide is erucamide, oleamide, linoleamide or mixtures thereof.

5. A process according to claim 1 wherein the one or more further additives are present and are selected from the group consisting of hindered amine light stabilizers, hindered phenols, phosphites, benzofuranone stabilizers, hydroxyphenylbenzotriazole, hydroxyphenyl-s-triazine, benzophenone ultraviolet light absorbers, nucleating agents, talcum, carbon black, calcium stearate and mixtures of two or more thereof.

6. A process according to claim 1 wherein the rubber modified polymer is a rubber modified polypropylene, the grafted polymer is polypropylene grafted with maleic anhydride or polyethylene grafted with maleic anhydride, and the unsaturated fatty acid amide is erucamide.

7. A process according to claim 1 , wherein the rubber modified polymer is a rubber-modified polypropylene.

8. A process according to claim 1 , wherein the filler comprises talc.

9. A process according to claim 1 , wherein

the grafted polymer is present in an amount of about 2 to about 10 weight %;

the friction reducing agent is present in an amount of about 0.3 to about 3 weight %;

the unsaturated fatty acid amide is present in an amount of about 0.2 to about 0.4 weight %;

the rubber modified polymer is present in an amount of about 60 to about 98 weight %;

the one or more further additives are present in an amount of about 0.1 to about 1 weight %;

and the filler is present from 25 to 40 weight %.

10. A process according to claim 1 , wherein the filler is selected from the group consisting of talc, Wollastonite, glass fibres, carbonfibres, calcium carbonate and mixtures thereof.