US5547722A
Expired / Lapsed
US
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Ethylene polymer and fuel tank comprising the same
Assignee: Mitsubishi Chemical Corp
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Filing: 1995-03-31
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Granted: 1996-08-20
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Expires: 2015-03-31
Abstract
Abstract An ethylene homopolymer or copolymer comprising ethylene and not more than 10% by weight of an alpha -olefin having from 3 to 20 carbon atoms and a fuel tank obtained therefrom are disclosed, said ethylene homopolymer or copolymer having (1) an intrinsic viscosity [ eta ] of from 2 to 6 dl/g, (2) a density of from 0.945 to 0.970 g/cm3, (3) an R value of from 2.5 to 4, said R value being defined as a sigma 2/ rho 1 ratio, wherein sigma 1 and sigma 2 mean stress in elongation with a strain at 2 sec and 4 sec, respectively, under a flow at an elongational strain rate +E,dot epsilon +EE of 0.5 sec-1, and (4) a relationship between high-velocity impact strength (HRI-IZOD) measured at -30 DEG C. and a melt index under a load of 21.6 kg (HLMI) satisfying formula: HRI-IZOD>/=-log HLMI+1.15 The ethylene polymer exhibits high melt tension and excellent molding properties such as uniform stretchability in blow molding to provide molded articles, such as a fuel tank, having excellent mechanical characteristics, such as high stiffness and high impact resistance, and excellent fire resistance.
Inventors
- 👤 Yumito Uehara
- 👤 Nobuo Enokido
- 👤 Kiyotoshi Fujioka
- 👤 Nobuyuki Shimizu
- 👤 Motonori Ueda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:02
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; C; C08; C08F; C08F110/00; C08F110/02; B32B1/00; B32B27/32; B32B27/34; B32B7/00; B32B7/04; B32B7/12; B60; B60K; B60K15/00; B60K15/03; C08F10/00; C08F10/02; C08F210/00; C08F210/16; B32B2307/00; B32B2307/70; B32B2307/72; B32B2307/724; B32B2307/7242; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1379; Y10T428/1383; Y10T428/31504; Y10T428/31725; Y10T428/31739; Y10T428/31743; Y10T428/31746; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
140 words
A fuel tank obtained by blow molding of an ethylene homopolymer or copolymer comprising ethylene and not more than 10% by weight of an α-olefin having from 3 to 20 carbon atoms, said ethylene polymer having (1) an intrinsic viscosity of from 2 to 6 dl/g, (2) a density of from 0.945 to 0.970 g/cm 3 , (3) an R value of from 2.5 to 4, said R value being defined as a σ 2 /σ 1 ratio, wherein σ 1 and σ 2 mean stress in elongation with a strain at 2 sec and 4 sec, respectively, under a flow at an elongational strain rate ε of 0.5 sec -1 , and (4) a relationship between high-velocity impact strength (HRI-IZOD) measured at -30° C. and a melt index under a load of 21.6 kg (HLMI) satisfying formula: HRI-IZOD≧-log HLMI+1.15
Claim 2
Dependent Claim
140 words
A fuel tank obtained by blow molding of an ethylene homopolymer or copolymer comprising ethylene and not more than 10% by weight of an α-olefin having from 3 to 20 carbon atoms, said ethylene polymer having (1) an intrinsic viscosity of from 2 to 6 dl/g, (2) a density of from 0.945 to 0.970 g/cm 3 , (3) an R value of from 2.5 to 4, said R value being defined as a σ 2 /σ 1 ratio, wherein σ 1 and σ 2 mean stress in elongation with a strain at 2 sec and 4 sec, respectively, under a flow at an elongational strain rate ε of 0.5 sec -1 , and (4) a relationship between high-velocity impact strength (HRI-IZOD) measured at -30° C. and a melt index under a load of 21.6 kg (HLMI) satisfying formula: HRI-IZOD≧-log HLMI+1.15
Claim 3
Dependent Claim
30 words
A fuel tank as claimed in claim 1, wherein said fuel tank has a laminate structure composed of a gas barrier layer and a polyethylene layer comprising said ethylene polymer.
Claim 4
Dependent Claim
38 words
A fuel tank as claimed in claim 2, wherein said fuel tank is composed of a gas barrier layer having laminated thereon at least one side thereof a polyethylene layer comprising said ethylene polymer via an adhesive layer.
Claim 5
Dependent Claim
17 words
A fuel tank as claimed in claim 2, wherein said gas barrier layer comprises a polyamide resin.
Claim 6
Dependent Claim
65 words
A fuel tank as claimed in claim 4, wherein said gas barrier layer is a composition comprising a polyamide resin and a maleic anhydride-modified ethylene-α-olefin copolymer having a degree of crystallization of from 1 to 35% and a melt index (HLMI) of from 0.01 to 50 g/10 min and being modified with maleic anhydride at a grafting ratio of from 0.05 to 1% by weight.
Claim 7
Dependent Claim
31 words
A fuel tank as claimed in claim 3, wherein said adhesive layer comprises high-density polyethylene modified with 0.01 to 1% by weight of an unsaturated carboxylic acid or an anhydride thereof.
Claim 8
Dependent Claim
65 words
The fuel tank as claimed in claimed in claim 1, wherein (1) the intrinsic viscosity is from 2.3 to 5.5 dl/g, (2) the density is from 0.955 to 0.970 g/cm 3 , (3) the R value is from 2.6 to 3.8, (4) the relationship between (HRI-IZOD) and (HLMI) satisfies the formula: HRI-IZOD≧-log HLMI+1.4, and (5) the melt tension (MT) satisfies the relationship: MI≧-12.4 log HLMI+23.5.
Claim 9
Dependent Claim
65 words
The fuel tank as claimed in claimed in claim 1, wherein (1) the intrinsic viscosity is from 3 to 5 dl/g, (2) the density is from 0.960 to 0.970 g/cm 3 , (3) the R value is from 2.7 to 3.5, (4) the relationship between (HRI-IZOD) and (HLMI) satisfies the formula: HRI-IZOD≧-log HLMI+1.4, and (5) the melt tension (MT) satisfies the relationship: MT≧-12.4 log HLMI+23.5.
Claim 10
Dependent Claim
54 words
The fuel tank as claimed in claimed in claim 1, wherein (1) the intrinsic viscosity is from 2.3 to 5.5 dl/g, (2) the density is from 0.955 to 0.970 g/cm 3 , (3) the R value is from 2.6 to 3.8, and (4) the relationship between (HRI-IZOD) and (HLMI) satisfies the formula: HRI-IZOD≧-log HLMI+1.4.
Claim 11
Dependent Claim
54 words
The fuel tank as claimed in claimed in claim 1, wherein (1) the intrinsic viscosity is from 3 to 5 dl/g, (2) the density is from 0.960 to 0.970 g/cm 3 , (3) the R value is from 2.7 to 3.5, and (4) the relationship between (HRI-IZOD) and (HLMI) satisfies the formula: HRI-IZOD≧-log HLMI+1.4.
Claim 12
Dependent Claim
18 words
The fuel tank as claimed in claim 2, wherein said gas barrier layer is made of nylon 6.
Claim 13
Dependent Claim
162 words
A fuel tank obtained by blow molding of an ethylene homopolymer or copolymer comprising ethylene and not more than 10% by weight of an α-olefin having from 3 to 20 carbon atoms, said ethylene polymer having (1) an intrinsic viscosity of from 2 to 6 dl/g, (2) a density of from 0.945 to 0.970 g/cm 3 , and (3) an R value of from 2.5 to 4, said R value of from 2.5 to 4, said R value being defined as a σ 2 /σ 1 ratio, wherein σ 1 and σ 2 mean stress in elongation with a strain at 2 sec and 4 sec, respectively, under a flow at an elongational strain rate ε of 0.5 sec -1 , (4) a relationship between high velocity impact strength (HRI-IZOD) measured at -30° C. and a melt index under a load of 21.6 kg (HLMI) satisfying the formula: HRI-IZOD≧-log HLMI+1.15, and (5) a melt tension (MT) satisfying the relationship: MT≧-12.4 log HLMI+20.5.
Claim 14
Dependent Claim
162 words
A fuel tank obtained by blow molding of an ethylene homopolymer or copolymer comprising ethylene and not more than 10% by weight of an α-olefin having from 3 to 20 carbon atoms, said ethylene polymer having (1) an intrinsic viscosity of from 2 to 6 dl/g, (2) a density of from 0.945 to 0.970 g/cm 3 , and (3) an R value of from 2.5 to 4, said R value of from 2.5 to 4, said R value being defined as a σ 2 /σ 1 ratio, wherein σ 1 and σ 2 mean stress in elongation with a strain at 2 sec and 4 sec, respectively, under a flow at an elongational strain rate ε of 0.5 sec -1 , (4) a relationship between high velocity impact strength (HRI-IZOD) measured at -30° C. and a melt index under a load of 21.6 kg (HLMI) satisfying the formula: HRI-IZOD≧-log HLMI+1.15, and (5) a melt tension (MT) satisfying the relationship: MT≧-12.4 log HLMI+20.5.
Claim 15
Dependent Claim
30 words
A fuel tank as claimed in claim 12, wherein said fuel tank has a laminate structure composed of a gas barrier layer and a polyethylene layer comprising said ethylene polymer.
Claim 16
Dependent Claim
18 words
The fuel tank as claimed in claim 12, wherein said gas barrier layer is made of nylon 6.
Claim 17
Dependent Claim
38 words
A fuel tank as claimed in claim 13, wherein said fuel tank is composed of a gas barrier layer having laminated on at least one side thereof a polyethylene layer comprising said ethylene polymer via an adhesive layer.
Claim 18
Dependent Claim
17 words
A fuel tank as claimed in claim 13, wherein said gas barrier layer comprises a polyamide resin.
Claim 19
Dependent Claim
66 words
A fuel tank as claimed in claim 16, wherein said gas barrier layer is a composition comprising said polyamide resin and a maleic anhydride modified ethylene-α-olefin copolymer having a degree of crystallization of from 1 to 35% and a melt index (HLMI) of from 0.01 to 50 g/10 min and being modified with maleic anhydride at a grafting ratio of from 0.05 to 1% by weight.
Claim 20
Dependent Claim
31 words
A fuel tank as claimed in claim 15, wherein said adhesive layer comprises high-density polyethylene modified with 0.01 to 1% by weight of an unsaturated carboxylic acid or an anhydride thereof.
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) | 1999-08-20 | 2000-02-19 | 2000-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-20 | 2004-02-19 | 2004-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-20 | 2008-02-19 | 2008-08-20 | $7700.00 | Window Closed / Lapsed |