Polymer films containing platelet particles
AssigneeAllied-Signal Inc.
InventorsWilliam Sacks, John P. Sibilia, Abraham M. Kotliar, Harold D. Oltman, Shu P. Chen
Life of this patent
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Abstract
Thin polymer films containing small sized platelet type filler. The polymer has a melt index of from 0.01 to 10 grams per 10 minutes at 190.degree. C. to 250.degree. C.as measured on ASTM Test No. D-1238 at a load of 1000 to 2160 grams. The preferred polymer is polycaprolactam or high density polyethylene. There is from 10 to 50 percent of a platelet filler having an average equivalent diameter of from 1 to 8 micrometers, a maximum equivalent diameter of about 25 micrometers, and an average thickness of less than 0.5 micrometers. The preferred filler is talc. The film is from 10 to 100 micrometers thick and can be a single ply or a laminate.
Claims23
A process to make film comprising a polymer having a melt index of from 0.01 to 10.0 g/10 minutes at 190.degree. C. to 250.degree. 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.
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.degree. C. to 250.degree. 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.degree. C. to 250.degree. 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.
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.degree. C. to 250.degree. 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.
Dependencies are inferred from the claim text.