Polymer films containing platelet particles

Claim 2

A process to make film comprising a polymer having a melt index of from 0.01 to 10.0 g/10 minutes at 190° C. to 250° C. as measured on ASTM Test NO. D-1238 at a load of 1000 to 2160 grams, from 10 to 50 weight percent based on the polymer and filler, of a platelet filler wherein the filler has an average equivalent diameter of from 1 to 8 micrometers, a maximum equivalent diameter of 25 micrometers, and a thickness of less than 0.5 micrometers, the filler being homogeneously distributed through the film, the film having a thickness of from 10 to 100 micrometers, the process comprising the steps of: stretching the film in the axial direction, and stretching the film in the transverse direction the film being stretched until the major plane of the filler is substantially parallel to the major plane of the film.

Claim 3

The process as recited in claim 1 wherein the polymer is high density polyethylene having a melt index of from 0.01 to 10 g/10 minutes as measured on ASTM Test No. D-1238 at a load of 2160 grams at 190° C.

Claim 4

The process as recited in claim 1 wherein the polymer is a polyamide having a melt index of from 0.01 to 10 g/10 minutes as measured on ASTM Test No. D-1238 at a load of 1000 grams at 235° C.

Claim 5

The process as recited in claim 1 wherein the filler is talc.

Claim 6

The process as recited in claim 1 wherein the step of forming the film comprises extruding the film through a tubular film die, drawing the extrudate in the axial direction and stretching the film in the transverse direction comprises blow forming the tubular film.

Claim 7

The process as recited in claim 5 wherein the tubular film is blown up to from 1.2 to 6 times in the transverse direction.

Claim 8

A process to make a film laminate comprising the steps of: coextruding at least one polymer layer with at least one additional polymer layer, the one polymer layer and the additional polymer layer being different thermoplastics, the one polymer layer comprising one thermoplastic having a melt index of from 0.01 to 10 g/10 minutes at 190° C. to 250° C. as measured on ASTM Test No. D-1238 at a load of 1000 to 2160 grams and from 10 to 50 weight percent based on the polymer and filler of a platelet filler wherein the filler has an average equivalent diameter of from 1 to 8 micrometers, a maximum equivalent diameter of 25 micrometers, and a thickness of less than 0.5 micrometers, the filler being homogeneously distributed through the one polymer layer, and the at least one additional polymer layer comprising the additional thermoplastic having a melt index of from 0.01 to 10.0 g/10 minutes at 190° C. to 250° C. as measured in ASTM Test No. D-1238 at a load of 1000 to 2160 grams, and from 10 to 50 weight percent, based on the polymer and filler, of a platelet filler wherein the filler has an average equivalent diameter from 1 to 8 micrometers, a maximum equivalent diameter of 25 micrometers, and thickness of less than 0.5 micrometers, the filler being homogeneously distributed through the additional polymer layer, the laminate having a thickness of from 10 to 100 micrometers; stretching the film laminate in the axial direction, and stretching the film laminate in the transverse direction the film layers being stretched until the major plane of filler is substantially parallel to the major plane of the film.

Claim 9

A process to make a film laminate comprising the steps of: coextruding at least one polymer layer with at least one additional polymer layer, the one polymer layer and the additional polymer layer being different thermoplastics, the one polymer layer comprising one thermoplastic having a melt index of from 0.01 to 10 g/10 minutes at 190° C. to 250° C. as measured on ASTM Test No. D-1238 at a load of 1000 to 2160 grams and from 10 to 50 weight percent based on the polymer and filler of a platelet filler wherein the filler has an average equivalent diameter of from 1 to 8 micrometers, a maximum equivalent diameter of 25 micrometers, and a thickness of less than 0.5 micrometers, the filler being homogeneously distributed through the one polymer layer, and the at least one additional polymer layer comprising the additional thermoplastic having a melt index of from 0.01 to 10.0 g/10 minutes at 190° C. to 250° C. as measured in ASTM Test No. D-1238 at a load of 1000 to 2160 grams, and from 10 to 50 weight percent, based on the polymer and filler, of a platelet filler wherein the filler has an average equivalent diameter from 1 to 8 micrometers, a maximum equivalent diameter of 25 micrometers, and thickness of less than 0.5 micrometers, the filler being homogeneously distributed through the additional polymer layer, the laminate having a thickness of from 10 to 100 micrometers; stretching the film laminate in the axial direction, and stretching the film laminate in the transverse direction the film layers being stretched until the major plane of filler is substantially parallel to the major plane of the film.

Claim 10

The process as recited in claim 7 wherein the one polymer is high density polyethylene having a melt index of from 0.01 to 10.0 g/10 minutes as measured on ASTM Test No. D-1238 at 2160 grams at 190° C.

Claim 11

The process as recited in claim 7 wherein the one polymer is a polyamide having a melt index of from 0.1 to 10.0 g/10 minutes as measured on ASTM Test No. D-1238 at 1000 grams at 235° C.

Claim 12

The process as recited in claim 8 wherein the additional polymer is a polyamide.

Claim 13

The process as recited in claim 7 wherein the filler is talc.

Claim 14

The process as recited in claim 7 wherein the step of forming the film comprises coextruding the one polymer layer and the additional polymer layer through a tubular film die, and the step of stretching the film laminate in the transverse direction comprises blow forming the tubular film.

Claim 15

The process as recited in claim 12 wherein the tubular film is blown up to from 1.2 to 6 times in the transverse direction.

Claim 16

The process as recited in claim 7 further comprising the step of coextruding an adhesive layer between the one thermoplastic layer and one additional thermoplastic film.

Claim 17

The process as recited in claim 1 or 7 wherein the film is stretched in the axial and machine direction until the platelet orientation factor is from 0.9 to 1.0.

Claim 18

A process of decreasing gas and vapor permeability of a film having at least one layer comprising the step of homogeneously incorporating a platelet shaped filler into at least one layer of the polymer film having a melt index of from 0.01 to 10.0 g/10 minutes at 190° C. to 250° C. as measured on ASTM Test No. D-1238 at a load of 1000 to 2160 grams, there being from 10 to 50 weight percent, based on the polymer and filler, of the filler having an average equivalent diameter of from 1 to 8 and a maximum equivalent diameter of 25 micrometers, and a platelet thickness of less than 0.5 micrometers and stretching the film to cause a plane through the plane of the filler to be substantially parallel to the plane of the film, the film having a thickness of from 10 to 100 micrometers.

Claim 19

A process of decreasing gas and vapor permeability of a film having at least one layer comprising the step of homogeneously incorporating a platelet shaped filler into at least one layer of the polymer film having a melt index of from 0.01 to 10.0 g/10 minutes at 190° C. to 250° C. as measured on ASTM Test No. D-1238 at a load of 1000 to 2160 grams, there being from 10 to 50 weight percent, based on the polymer and filler, of the filler having an average equivalent diameter of from 1 to 8 and a maximum equivalent diameter of 25 micrometers, and a platelet thickness of less than 0.5 micrometers and stretching the film to cause a plane through the plane of the filler to be substantially parallel to the plane of the film, the film having a thickness of from 10 to 100 micrometers.

Claim 20

The process as recited in claim 16 wherein the thermoplastic is a polyamide.

Claim 21

The process as recited in claim 16 wherein the thermoplastic is high density polyethylene.

Claim 22

The process as recited in claim 16 wherein the filler is talc.

Claim 23

The process as recited in claim 16 wherein the step of causing the filler and film to be substantially parallel results in a platelet orientation factor of from 0.9 to 1.0.

Claim 24

The process as recited in claim 1 wherein the film is stretched until the platelet orientation factor of the platelets in the film is from 0.70 to 1.0.

Claim 25

The process as reoited in claim 7 wherein the film laminate is stretched until the platelet orientation factor of the platelet filler in the film layers is from 0.70 to 1 0.

Claim 26

The process as recited in claim 16 wherein the film is stretched until the platelet orientation factor of the platelets in the film is from 0.70 to 1.0.