Patent US4560598A successfully refreshed from Google Patents.
US4560598A
Expired / Lapsed
US
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Plastics film and bags and sacks therefrom
Assignee: STIKSACK STS SA A CORP OF SWISS
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Filing: 1984-12-10
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Granted: 1985-12-24
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Expires: 2004-12-10
Abstract
Abstract A thermoplastics bag whose wall has an outer layer and an inner layer, each of which is formed by melt-extrusion from an ethylene polymer, the outer layer containing an isobutylene polymer in an amount sufficient to increase the coefficient of friction. Also a multi-layer film suitable for use in the manufacture of the bag.
Inventors
- 👤 Michael A. Cowan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:01
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B1/00; B32B1/08; B32B27/32; B32B27/322; C; C09; C09D; C09D123/00; C09D123/02; C09D123/04; C09D123/06; C09J; C09J123/00; C09J123/02; C09J123/04; C09J123/08; C09J123/0807; C09J123/0815; B32B2307/00; B32B2307/70; B32B2307/718; B32B2323/00; B32B2323/04; B32B2323/043; B32B2323/046; B32B2439/00; B32B2439/02; B32B2439/06; C08; C08L; C08L2666/00; C08L2666/02; C08L2666/04; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1334; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
124 words
A thermoplastics sack or bag at least one of the walls of which has an outer layer and an inner layer, each of which is formed by melt-extrusion from a polymer composition selected from the group consisting of (a) at least one polyethylene selected from the group consisting of homopolymers of ethylene and copolymers of ethylene with up to 5 mole % of at least one other α-olefin and (b) blends of at least one said polyethylene with minor proportions of other polymeric materials compatible therewith, and the outer layer contains an isobutylene polymer in an amount sufficient to increase the coefficient of friction, and wherein the surface of said inner layer has a lower coefficient of friction than that of said outer layer.
Claim 2
Dependent Claim
124 words
A thermoplastics sack or bag at least one of the walls of which has an outer layer and an inner layer, each of which is formed by melt-extrusion from a polymer composition selected from the group consisting of (a) at least one polyethylene selected from the group consisting of homopolymers of ethylene and copolymers of ethylene with up to 5 mole % of at least one other α-olefin and (b) blends of at least one said polyethylene with minor proportions of other polymeric materials compatible therewith, and the outer layer contains an isobutylene polymer in an amount sufficient to increase the coefficient of friction, and wherein the surface of said inner layer has a lower coefficient of friction than that of said outer layer.
Claim 3
Dependent Claim
16 words
A sack or bag as claimed in claim 1 in which the layers are fused together.
Claim 4
Dependent Claim
17 words
A sack or bag as claimed in claim 2 in which said layers are formed by coextrusion.
Claim 5
Dependent Claim
36 words
A sack or bag as claimed in claim 3 in which the isobutylene polymer is present in the outer layer in an amount of less than 10% by weight, based on the polyethylene in the layer.
Claim 6
Dependent Claim
29 words
A sack or bag as claimed in claim 4 in which the isobutylene polymer is present in the outer layer in an amount of less than 8% by weight.
Claim 7
Dependent Claim
30 words
A sack or bag as claimed in claim 5 in which the isobutylene polymer is present in the outer layer in an amount of from 1% to 6% by weight.
Claim 8
Dependent Claim
15 words
A sack or bag as claimed in claim 4 wherein the isobutylene polymer is polyisobutylene.
Claim 9
Dependent Claim
28 words
A sack or bag as claimed in claim 7 in which the polyisobutylene has a molecular weight M w (polyethylene equivalent) in the range of 500 to 5000.
Claim 10
Dependent Claim
31 words
A sack or bag as claimed in claim 1 in which the surface coefficient of friction of the outer layer, as measured by ASTM D-1894 (static test), is at least 0.8.
Claim 11
Dependent Claim
31 words
A sack or bag as claimed in claim 9 in which the surface coefficient of friction of the outer layer, as measured by ASTM D-1894 (static test), is at least 0.85.
Claim 12
Dependent Claim
31 words
A sack or bag as claimed in claim 10 in which the surface coefficient of friction of the outer layer, as measured by ASTM D-1894 (static test), is at least 0.87.
Claim 13
Dependent Claim
31 words
A sack or bag as claimed in claim 1 in which the surface coefficient of friction of the inner layer, as measured by ASTM D-1894 (static test), is less than 0.5.
Claim 14
Dependent Claim
21 words
A sack or bag as claimed in claim 1 in which said outer and inner layers each comprise low density polyethylene.
Claim 15
Dependent Claim
19 words
A sack or bag as claimed in claim 1 in which the outer layer comprises linear low density polyethylene.
Claim 16
Dependent Claim
46 words
A sack or bag as claimed in claim 14 in which the inner layer comprises a material selected from the group consisting of linear low density polyethylene, a polyethylene of higher density or a mixture of linear low density polyethylene and a polyethylene of higher density.
Claim 17
Dependent Claim
27 words
A sack or bag as claimed in claim 1 in which one of the layers comprises low density polyethylene and the other comprises linear low density polyethylene.
Claim 18
Dependent Claim
18 words
A sack or bag as claimed in claim 16 in which said other layer is the outer layer.
Claim 19
Dependent Claim
34 words
A thermoplastic sack or bag as claimed in claim 1 wherein said other polymeric materials are selected from the group consisting of ethylene/alpha-olefin copolymers containing more than about 5% alpha-olefin and polymers of propylene.
Claim 20
Dependent Claim
57 words
A sack or bag in accordance with claim 9 in which the isobutylene polymer is present in the outer layer in an amount of less than 10% by weight, based on the polyethylene in the layer; and the surface coefficient of friction of the inner layer, as measured by ASTM D-1894 (static test), is less than 0.5.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |