US4737536A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automobile bumper formed of thermoplastic multicomponent resin
Assignee: Nissan Motor Co Ltd
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Filing: 1986-06-16
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Granted: 1988-04-12
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Expires: 2006-06-16
Abstract
Abstract Disclosed is an automobile bumper which is formed of a thermoplastic multicomponent resin composition and which is improved in weatherability and impact resistance at low temperatures and also in surface glossiness. Essentially the resin composition is a blend of 22-28 wt % of a hydrogenated block copolymer of an aromatic vinyl compound such as styrene and a conjugated diene such as butadiene, 32-56 wt % of a propylene-ethylene block copolymer in which the content of ethylene is 1-10 wt % and 22-28 wt % of an ethylene-propylene copolymer rubber. Optionally, up to 5 wt % of talc and/or up to 7 wt % of low-pressure low-density polyethylene may be added. Some physical properties of the ingredients are specified such that the resin composition has a melt index not lower than 5 g/10 min at 230° C. under load of 2.16 kg and a modulus of elasticity in bending in the range from 2000 to 4000 kg/cm 2 .
Inventors
- 👤 Toyo Kawase
- 👤 Yukio Okada
- 👤 Yujiro Kawamura
- 👤 Masashi Ohno
- 👤 Takashi Sugimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:50
CPC Classifications
C; C08; C08L; C08L53/00; C08L53/02; C08L53/025
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
272 words
An automobile bumper member formed of a thermoplastic resin composition which consists essentially of: (a) 22-28 wt % of a hydrogenated block copolymer which is represented, before hydrogenation, by the general formula A--B--A) n , wherein A represents a block of polymer of a monovinyl substituted aromatic hydrocarbon, B represents a block of an elastomeric polymer of a conjugated diene and n is an integer from 1 to 5, the melt index of said hydrogenated block copolymer at 230° C. under load of 5 kg being in the range from 1 to 15 g/10 min; (b) 32-56 wt % of a propylene-ethylene block copolymer in which the content of ethylene is 1-10 wt % and which comprises 5-20 wt % of a soluble portion which is soluble in xylene at room temperature and contains 25-35 wt % of ethylene, the melt index of said propylene-ethylene block copolymer at 230° C. under load of 2.16 kg being in the range from 50 to 100 g/10 min; (c) 22-28 wt % of an ethylene-propylene copolymer rubber of which the Mooney viscosity at 100° C. is in the range from 10 to 65; (d) 0-5 wt % of talc: and (e) 0-7 wt % of a low-pressure low-density polyethylene of which the melt index at 190° C. under load of 2.16 kg is in the range from 10 to 50 g/10 min, the melt index of said resin composition at 230° C. under load of 2.16 kg being not lower than 5 g/10 min, the modulus of elasticity in bending of said resin composition being in the range from 2000 to 4000 kg/cm 2 .
Claim 2
Dependent Claim
272 words
An automobile bumper member formed of a thermoplastic resin composition which consists essentially of: (a) 22-28 wt % of a hydrogenated block copolymer which is represented, before hydrogenation, by the general formula A--B--A) n , wherein A represents a block of polymer of a monovinyl substituted aromatic hydrocarbon, B represents a block of an elastomeric polymer of a conjugated diene and n is an integer from 1 to 5, the melt index of said hydrogenated block copolymer at 230° C. under load of 5 kg being in the range from 1 to 15 g/10 min; (b) 32-56 wt % of a propylene-ethylene block copolymer in which the content of ethylene is 1-10 wt % and which comprises 5-20 wt % of a soluble portion which is soluble in xylene at room temperature and contains 25-35 wt % of ethylene, the melt index of said propylene-ethylene block copolymer at 230° C. under load of 2.16 kg being in the range from 50 to 100 g/10 min; (c) 22-28 wt % of an ethylene-propylene copolymer rubber of which the Mooney viscosity at 100° C. is in the range from 10 to 65; (d) 0-5 wt % of talc: and (e) 0-7 wt % of a low-pressure low-density polyethylene of which the melt index at 190° C. under load of 2.16 kg is in the range from 10 to 50 g/10 min, the melt index of said resin composition at 230° C. under load of 2.16 kg being not lower than 5 g/10 min, the modulus of elasticity in bending of said resin composition being in the range from 2000 to 4000 kg/cm 2 .
Claim 3
Dependent Claim
30 words
A bumper member according to claim 1, wherein the surface glossiness of said resin composition is not lower than 60% in terms of specular gloss measured by the 60°-60° method.
Claim 4
Dependent Claim
19 words
A bumper member according to claim 1, wherein said monovinyl substituted aromatic hydrocarbon is selected from styrene and α-methylstyrene.
Claim 5
Dependent Claim
26 words
A bumper member according to claim 1, wherein said conjugated diene is selected from the group consisting of butadiene, isoprene and mixtures of butadiene and isoprene.
Claim 6
Dependent Claim
25 words
A bumper member according to claim 1, wherein said polymer of a conjugated diene is polybutadiene in which a microstructure of 1,2-butadiene amounts to 20-50%.
Claim 7
Dependent Claim
51 words
A bumper member according to claim 1, wherein said block copolymer represented by said general formula is hydrogenated such that at least 50% of the olefinic double bonds in the block B undergo hydrogenation whereas not more than 25 % of the aromatic unsaturated bonds in the block A undergo hydrogenation.
Claim 8
Dependent Claim
24 words
A bumper member according to claim 1, wherein the melt index of said propylene-ethylene block copolymer is in the range from 60 to 80.
Claim 9
Dependent Claim
18 words
A bumper member according to claim 1, wherein said ethylene-propylene copolymer rubber contains 25-50 wt % of propylene.
Claim 10
Dependent Claim
29 words
A bumper member according to claim 1, wherein said talc is 0.2-25 μm in mean particle size and not smaller than 30,000 cm 2 /g in specific surface area.
References Cited (Backward Citations)
US4371602A
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JPS60132968A
Cited
JPS61168203A
Cited
JPH1034048A
Cited
JPH1097349A
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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) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |