Porous PTFE materials and articles produced therefrom
First Claim
Patent Images
1. An article comprisinga porous PTFE membrane formed by a method comprisingforming an extruded lubricated tape of PTFE polymer by a paste extrusion process;
- stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant;
longitudinally expanding the resulting tape;
then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=5.13×
10−
3 (Bubble Point)−
1.26 and a surface area of at least 20 m2/g.
1 Assignment
0 Petitions
Accused Products
Abstract
Novel porous PTFE membranes are described possessing a unique combination of high strength, low flow resistance, and small pore size. Additionally, unique constructions with superior filtration and venting properties incorporating porous PTFE membranes are described.
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Citations
96 Claims
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1. An article comprising
a porous PTFE membrane formed by a method comprising forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=5.13×
10−
3 (Bubble Point)−
1.26 and a surface area of at least 20 m2/g. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a light transmission of at least 50% and a porosity of at least 50%. - View Dependent Claims (11, 12)
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13. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a bubble point of at least 448 kPa and a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=2.60×
10−
3 (Bubble Point)−
0.54. - View Dependent Claims (14, 15, 16)
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17. A porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a product of matrix tensile strengths in two orthogonal directions of at least 1.3×
105 MPa2. - View Dependent Claims (18, 19, 20)
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21. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=5.13×
10−
3 (Bubble Point)−
1.26 and a product of matrix tensile strengths in two orthogonal directions of at least 1.3×
105 MPa2. - View Dependent Claims (22, 23, 24, 25, 26)
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27. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a water entry pressure versus Gurley number equal to or above the line defined by the equation WEP=3(Gurley)+2500. - View Dependent Claims (28, 29, 30, 31, 32, 33)
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34. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
3.5×
10−
3 (Bubble Point)+1.3. - View Dependent Claims (35, 36, 37)
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38. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a water flux rate versus mean flow pore size equal to or above the line defined by the equation log (water flux rate)=16.9 (mean flow pore size)−
1.85. - View Dependent Claims (39, 40, 41)
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42. An article comprising a composite of at least one porous PTFE membrane and at least one additional layer, said porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said composite having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
3.5×
10−
3 (Bubble Point)+1.3. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. An article comprising a composite of at least one porous PTFE membrane and at least one additional layer, said porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said composite further being instantly wettable with water, said composite having a water flux rate versus bubble point equal to or greater than the line defined by the equation log (Water Flux Rate)=−
0.01 (Bubble Point)+1.3. - View Dependent Claims (55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65)
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66. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane being instantly wettable with water, said membrane having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
0.01 (Bubble Point)+1.3. - View Dependent Claims (67, 68, 69)
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70. An article comprising at least one porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having an oleophobic treatment thereon and an oil rating of at least 2, said article having a water entry pressure above 1250 kPa and a Gurley number of greater than 0 and less than 200 seconds. - View Dependent Claims (71, 72, 73, 74)
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75. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; -
stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=5.13×
10−
3 (Bubble Point)−
1.22 and a light transmission of at least 50%. - View Dependent Claims (76, 77, 78)
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79. A method of filtering a fluid comprising:
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providing a filter comprising a porous PTFE membrane formed by a method comprising forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
3.5×
10−
3 (Bubble Point)+1.3; andflowing a fluid containing particle through said filter; thereby filtering said particles from said fluid.
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80. A method of filtering a fluid comprising:
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providing a filter comprising a porous PTFE membrane formed by a method comprising forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane having a water flux rate versus mean flow pore size equal to or above the line defined by the equation log (water flux rate)=16.9 (mean flow pore size)−
1.85; andflowing a fluid containing contaminants through said filter; thereby filtering said particles from said fluid.
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81. A method of filtering a fluid comprising:
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providing a filter comprising a composite of at least one porous PTFE membrane and at least one additional layer, said porous PTFE membrane formed by a method comprising forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said composite having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
3.5×
10−
3 (Bubble Point)+1.3; andflowing a fluid containing particle through said filter; thereby filtering said particles from said fluid. - View Dependent Claims (83)
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82. A method of filtering a fluid comprising:
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providing a filter comprising a porous PTFE membrane formed by a method comprising forming an extruded lubricated tape of PTFE polymer by a paste extrusion process; stretching the extruded lubricated tape transversely, and drying the stretched tape to remove lubricant; longitudinally expanding the resulting tape; then transversely expanding the tape at an expansion ratio of 20;
1 or greater,said porous PTFE membrane instantly wettable with water, said membrane having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
0.01 (Bubble Point)+1.3; andflowing a fluid containing particle through said filter; thereby filtering said particles from said fluid.
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84. An article comprising
a porous PTFE membrane formed by a method comprising: -
forming an extruded lubricated tape of PTFE polymer by a paste forming process; stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=5.13×
10−
3 (Bubble Point)−
1.26 and a surface area of at least 20 m2/g.
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85. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a light transmission of at least 50% and a porosity of at least 50%.
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86. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a bubble point of at least 448 kPa and a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=2.60×
10−
3 (Bubble Point)−
0.54.
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87. A porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a product of matrix tensile strengths in two orthogonal directions of at least 1.3×
105 MPa2.
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88. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=5.13×
10−
3 (Bubble Point)−
1.26 and a product of matrix tensile strengths in two orthogonal directions of at least 1.3×
105 MPa2.
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89. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a water entry pressure versus Gurley number equal to or above the line defined by the equation WEP=3(Gurley)+2500.
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90. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
3.5×
10−
3 (Bubble Point)+1.3.
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91. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a water flux rate versus mean flow pore size equal to or above the line defined by the equation log (water flux rate)=16.9 (mean flow pore size)−
1.85.
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92. An article comprising a composite of at least one porous PTFE membrane and at least one additional layer, said porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said composite having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
3.5×
10−
3 (Bubble Point)+1.3.
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93. An article comprising a composite of at least one porous PTFE membrane and at least one additional layer, said porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said composite further being instantly wettable with water, said composite having a water flux rate versus bubble point equal to or greater than the line defined by the equation log (Water Flux Rate)=−
0.01 (Bubble Point)+1.3.
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94. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane being instantly wettable with water, said membrane having a water flux rate versus bubble point equal to or above the line defined by the equation log (Water Flux Rate)=−
0.01 (Bubble Point)+1.3.
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95. An article comprising at least one porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having an oleophobic treatment thereon and an oil rating of at least 2, said article having a water entry pressure above 1250 kPa and a Gurley number of greater than 0 and less than 200 seconds.
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96. An article comprising a porous PTFE membrane formed by a method comprising
forming an extruded lubricated tape of PTFE polymer by a paste forming process; -
stretching the extruded lubricated tape transversely at a ratio of at least 3;
1, and drying the stretched tape to remove lubricant;longitudinally expanding the resulting tape at a temperature above 327°
C.;then transversely expanding the tape at a temperature above 327°
C.,said porous PTFE membrane having a Gurley versus bubble point equal to or below the line defined by the equation log (Gurley)=5.13×
10−
3 (Bubble Point)−
1.22 and a light transmission of at least 50%.
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Specification