Reinforced Multi-Layer Polymeric Films and Methods of Forming Same
OwnerHugh Joseph O'Donnell, Daniel Charles Peck +1inventors
InventorsHugh Joseph O'Donnell, Daniel Charles Peck, Pier-Lorenzo Caruso
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Abstract
A multi-layer film that includes at least one polymeric skin layer and polymeric “A” layer is provided. The polymeric “A” layer is formed from a composition that includes a soft or base polymer matrix and a hard polymer substantially disposed therein to form a reinforcing structure in the polymer matrix. The multi-layer film may also include a polymeric “B” layer that has a hard polymer substantially disposed therein. Methods of forming a multi-layer film are also provided.
Claims21
A multi-layer polymeric film having a thickness, said film comprising:
- a) at least one polymeric skin layer;
- b) a polymeric “A” layer joined at least indirectly to said skin layer, said “A” layer having a thickness and comprising a first composition comprising a first base polymer matrix and about 5 to about 40 volume percent of a hard polymer substantially disposed therein to form a structure in said polymer matrix;
- and
- c) a polymeric “B” layer joined to said “A” layer, said “B” layer having a thickness and comprising a second composition comprising a second base polymer matrix and about 5 to about 40 volume percent of a hard polymer substantially disposed therein, wherein at least one of the hard polymers in the “A” layer and the “B” layer is immiscible and void initiating when the film is stretched, and the “A” layer and the “B” layer are adjacent and differ in at least one of the following:
- i) the first base polymer and the second base polymer differ;
- ii) volumetric concentration of said hard polymer differ;
- iii) wherein at least one of said “A” layer and said “B” layer comprises a compatabilizer, and said “A” and “B” layers differ in the level or type of compatabilizer;
- and
- iv) layer thickness differ by at least about 20%, and
- wherein the at least one skin layer has a thickness, or total thickness, if more than one, that is from about 20 to about 60% of the thickness of the multi-layer polymeric film.
A method of forming a multi-layer polymeric film, the method comprising:
- a) preparing a first composition, the first composition comprising a first base polymer having an elastic modulus and a first hard polymer, the first hard polymer being immiscible in the first base polymer, wherein the first material has a higher elastic modulus than the first base polymer;
- b) preparing a second composition, the second composition comprising a second base polymer having an elastic modulus and a second hard polymer, the second hard polymer having a higher elastic modulus than the second base polymer, and being immiscible in the second base polymer after being formed into a layer, wherein least one of the hard polymers in the “A” layer and the “B” layer void initiating when the film is stretched;
- c) preparing a third composition comprising a polymer, which is substantially free of hard polymers;
- and
- d) coextruding the first, second and third compositions into a structure in which the first and second compositions form adjacent layers, and the third composition forms a skin layer forming one of the outer surfaces of the multi-layer polymeric film wherein “A” layer and the “B” layer are adjacent and differ in at least one of the following:
- i) the first base polymer and the second base polymer differ;
- ii) volumetric concentration of said hard polymer differ;
- iii) wherein at least one of said “A” layer and said “B” layer comprises a compatabilizer, and said “A” and “B” layers differ in the level or type of compatabilizer;
- and
- iv) layer thickness differ by at least about 20%, and
- wherein the at least one skin layer has a thickness, or total thickness, if more than one, that is from about 20 to about 60% of the thickness of the multi-layer polymeric film.
Dependencies are inferred from the claim text.