Polypropylene compounds having non-migratory slip properties

1. A masterbatch for polypropylene, comprising in weight percent of the masterbatch:

(a) from 45 to 81 weight percent of polypropylene carrier,

(b) from 5 to 10 weight percent of epoxy functionalized polysiloxane,

(c) from 9 to 45 weight percent of functionalized polyolefin, and

(d) optionally, from 0 to 10 weight percent of other additives;

wherein the functionalized polyolefin contains a maleic anhydride group and is a grafting agent for the epoxy functionalized polysiloxane.

2. The masterbatch of claim 1 , wherein the functionalized polyolefin is selected from the group consisting of maleic anhydride grafted polypropylene, maleic anhydride polypropylene copolymer, ethylene ethyl acrylate maleic anhydride terpolymer, and combinations of them.

3. A polypropylene compound comprising the masterbatch of claim 1 and polypropylene resin.

4. A polypropylene compound comprising:

(a) polypropylene matrix and

(b) a slip additive comprising in weight percent of the slip additive

(i) from 45 to 81 weight percent of polypropylene carrier,

(ii) from 5 to 10 weight percent of epoxy functionalized polysiloxane,

(ii) from 9 to 45 weight percent of functionalized polyolefin, and

(iv) optionally, from 0 to 10 weight percent of other additives;

wherein the functionalized polyolefin contains a maleic anhydride group and is a grafting agent for the epoxy functionalized polysiloxane.

5. The polypropylene compound of claim 4 , wherein the functionalized polyolefin is miscible with the polypropylene matrix.

6. The polypropylene compound of claim 4 , wherein the additive is selected from the group consisting of anti-blocking agents; adhesion promoters; biocides (antibacterials, fungicides, and mildewcides), anti-fogging agents; anti-static agents; bonding, blowing and foaming agents; dispersants; fillers and extenders; fire and flame retardants and smoke suppressants; impact modifiers; initiators; lubricants; micas; pigments, colorants and dyes; plasticizers; processing aids; other slip or release agents; silanes, titanates and zirconates; stabilizers; stearates; ultraviolet light absorbers; viscosity regulators; waxes; and combinations of them.

7. The polypropylene compound of claim 4 , wherein one or more additives are added in the form of a masterbatch concentrate.

8. The polypropylene compound of claim 4 , in the shape of a molded plastic article, an extruded plastic article, or a calendered plastic article.

9. A film having at least one layer comprised of the polypropylene compound of claim 4 .

10. A laminate of the film of claim 9 , wherein there is more than one film layer, and wherein each layer comprises same or different ingredients.

11. The laminate of claim 10 , wherein there is a skin layer contacting one surface of a core layer also having an opposing surface; and wherein the skin layer has a thickness between about 0.5 microns and about 1 millimeter.

12. The laminate of claim 11 , further comprising a second skin layer contacting the opposing surface of the core layer, wherein the core layer comprises polyolefin resin.

13. The laminate of claim 11 , wherein the skin layer has dynamic coefficient of friction value of 0.4 or less and static coefficient of friction value of 0.6 or less, according to the ASTM D1894-01 method, within 1 day after manufacturing of the laminate.

14. The laminate of claim 11 , wherein the change between static coefficient of friction and dynamic coefficient of friction values of the skin layer within 1 day after manufacturing and 20 days after manufacturing, according to the ASTM D1894-01 method, is 15% or less.

15. The laminate of claim 11 , wherein there is essentially no migration of the slip additive from the skin layer into another film layer measured 12 weeks after manufacturing.