US4093692A
Expired / Lapsed
US
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Melt extrusion process
Assignee: Chevron USA Inc
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Filing: 1977-03-21
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Granted: 1978-06-06
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Expires: 1997-03-21
Abstract
Abstract This application discloses a melt extrusion process for preparing articles of manufacture of improved properties from very high molecular weight linear ethylene polymers having an annealed density greater than about 0.94 gms/ml. The ethylene polymer employed in the process has melt flow properties such that the relationship between its slope parameter (S) and its apparent melt viscosity in poises at 1 sec. -1 (A o ) is defined by the formula: S≧0.0830A.sub.o - 0.442 where S is the negative slope of the curve obtained from a plot of the natural logarithm of the polymer's apparent melt viscosity in poises versus the natural logarithm of the apparent shear rate in sec. -1 at 190° C, said slope measured at 10 sec. -1 ; and where A o is the natural logarithm of the polymer's melt viscosity in poises measured at 1 sec. -1 at 190° C. The ethylene polymer has an S value in the range of about 0.61 to about 0.90 and an A o value in the range of about 12.0 to about 14.5. The ethylene polymer is extruded at a shear stress of less than about 3 × 10 6 dynes/cm 2 .
Inventors
- 👤 Donald R. J. Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:34
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/022; B29C48/03; B29C48/09; B29C48/10; B29K; B29K2023/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
186 words
A process for preparing a melt extruded article of manufacture having improved physical properties which consists essentially of preparing such article by melt extruding a linear ethylene polymer at a shear stress of less than about 3 × 10 6 dynes/cm 2 , said ethylene polymer being characterized by: (a) having an annealed density of at least about 0.96 gms/ml, (b) having melt flow properties such that the relationship between its slope parameter (s) and its apparent melt viscosity in poises at 1 sec. -1 (A o ) is defined by the formula: S≧0.0830A.sub.o - 0.442 where S is the negative slope of the curve obtained from a plot of the natural logarithm of the polymer's apparent viscosity in poises versus the natural logarithm of the apparent shear rate in sec. -1 ; and where A o is the natural logarithm of the polymer's apparent viscosity in poises measured at 1 sec. -1 at 190° C; (c) having an A o value in the range of about 12.0 to about 14.5; and (d) having an S value in the range of about 0.61 to about 0.90.
Claim 2
Dependent Claim
186 words
A process for preparing a melt extruded article of manufacture having improved physical properties which consists essentially of preparing such article by melt extruding a linear ethylene polymer at a shear stress of less than about 3 × 10 6 dynes/cm 2 , said ethylene polymer being characterized by: (a) having an annealed density of at least about 0.96 gms/ml, (b) having melt flow properties such that the relationship between its slope parameter (s) and its apparent melt viscosity in poises at 1 sec. -1 (A o ) is defined by the formula: S≧0.0830A.sub.o - 0.442 where S is the negative slope of the curve obtained from a plot of the natural logarithm of the polymer's apparent viscosity in poises versus the natural logarithm of the apparent shear rate in sec. -1 ; and where A o is the natural logarithm of the polymer's apparent viscosity in poises measured at 1 sec. -1 at 190° C; (c) having an A o value in the range of about 12.0 to about 14.5; and (d) having an S value in the range of about 0.61 to about 0.90.
Claim 3
Dependent Claim
24 words
A process of claim 1 in which the ethylene polymer has an A o value in the range of about 12.2 to about 14.0.
Claim 4
Dependent Claim
227 words
A process for preparing an ethylene polymer film which has values for elongation at break measured in the machine direction and in the traverse direction that are similar and which has a low gel content, nearly all of such gels having diameters of less than 1/32 inch, which process consists essentially of blow extruding a linear ethylene polymer through annular die at a shear stress of less than about 3 × 10 6 dynes/cm 2 , said ethylene polymer: (a) having an annealed density of at least about 0.96 gms/ml. (b) having melt flow properties such that the relationship between its slope parameter S and its apparent melt viscosity in poises at 1 sec. -1 A o is defined by the formula: S≧0.0830 A.sub.o - 0.442 where S is the negative slope of the curve obtained from a plot of the natural logarithm of the polymer's apparent melt viscosity in poises versus the natural logarithm of the apparent shear rate in sec. -1 at 190° C, said slope measured at 10 sec. -1 ; and where A o is the natural logarithm of the polymer's apparent viscosity in poises measured at 1 sec. -1 at 190° C; (c) having an A o value in the range of about 12.0 to about 14.5; and (d) having an S value in the range of about 0.61 to about 0.90.
Claim 5
Dependent Claim
227 words
A process for preparing an ethylene polymer film which has values for elongation at break measured in the machine direction and in the traverse direction that are similar and which has a low gel content, nearly all of such gels having diameters of less than 1/32 inch, which process consists essentially of blow extruding a linear ethylene polymer through annular die at a shear stress of less than about 3 × 10 6 dynes/cm 2 , said ethylene polymer: (a) having an annealed density of at least about 0.96 gms/ml. (b) having melt flow properties such that the relationship between its slope parameter S and its apparent melt viscosity in poises at 1 sec. -1 A o is defined by the formula: S≧0.0830 A.sub.o - 0.442 where S is the negative slope of the curve obtained from a plot of the natural logarithm of the polymer's apparent melt viscosity in poises versus the natural logarithm of the apparent shear rate in sec. -1 at 190° C, said slope measured at 10 sec. -1 ; and where A o is the natural logarithm of the polymer's apparent viscosity in poises measured at 1 sec. -1 at 190° C; (c) having an A o value in the range of about 12.0 to about 14.5; and (d) having an S value in the range of about 0.61 to about 0.90.
Claim 6
Dependent Claim
24 words
A process of claim 3 in which the ethylene polymer has an A o value in the range of about 12.2 to about 14.0.
Claim 7
Dependent Claim
216 words
A process for preparing a large blow molded article having improved physical properties which consists essentially of extruding a parison of a linear ethylene polymer at a shear stress of less than about 3 × 10 6 dynes/cm 2 into a mold, clamping the parison in the mold, and injecting gas into the parison to expand the parison to conform to the walls of the mold, said ethylene polymer: (a) having an annealed density of at least about 0.96 gms/ml, (b) having melt flow properties such that the relationship between its slope parameter S and its apparent melt viscosity in poises at 1 sec. -1 A o is defined by the formula: S≧0.0830A.sub.o - 0.442 where S is the negative slope of the curve obtained from a plot of the natural logarithm of the polymer's apparent melt viscosity in poises versus the natural logarithm of the apparent shear rate in sec. -1 at 190° C, said slope measured at 10 sec. -1 ; and where A o is the natural logarithm of the polymer's apparent viscosity in poises measured at 1 sec. -1 at 190° C; (c) having an A o value in the range of about 12.0 to about 14.5; and (d) having an S value in the range of about 0.61 to about 0.90.
Claim 8
Dependent Claim
216 words
A process for preparing a large blow molded article having improved physical properties which consists essentially of extruding a parison of a linear ethylene polymer at a shear stress of less than about 3 × 10 6 dynes/cm 2 into a mold, clamping the parison in the mold, and injecting gas into the parison to expand the parison to conform to the walls of the mold, said ethylene polymer: (a) having an annealed density of at least about 0.96 gms/ml, (b) having melt flow properties such that the relationship between its slope parameter S and its apparent melt viscosity in poises at 1 sec. -1 A o is defined by the formula: S≧0.0830A.sub.o - 0.442 where S is the negative slope of the curve obtained from a plot of the natural logarithm of the polymer's apparent melt viscosity in poises versus the natural logarithm of the apparent shear rate in sec. -1 at 190° C, said slope measured at 10 sec. -1 ; and where A o is the natural logarithm of the polymer's apparent viscosity in poises measured at 1 sec. -1 at 190° C; (c) having an A o value in the range of about 12.0 to about 14.5; and (d) having an S value in the range of about 0.61 to about 0.90.
Claim 9
Dependent Claim
24 words
A process of claim 5 in which the ethylene polymer has an A o value in the range of about 12.2 to about 14.0.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |