US4918130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Eraser
Assignee: Buncho Corp
•
Filing: 1988-12-09
•
Granted: 1990-04-17
•
Expires: 2008-12-09
Abstract
Abstract An eraser comprises a styrene thermoplastic elastomer as a matrix with a hydrocarbon resin and a polyolefin included therein. The styrene thermoplastic elastomer is selected from the group which consists of styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-ethylene-butylene copolymers and styrene-ethylene-propylene copolymers, and the hydrocarbon is a terpene resin or hydrogenated terpene resin, and the polyolefin is polyethylene or polypropylene.
Inventors
- 👤 Yosimi Kano
- 👤 Koji Seki
- 👤 Ryoichi Seki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:25
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/18; C08K3/24; C08K3/26; C08L; C08L9/00; C08L9/06; C08K5/00; C08K5/01; C08L23/00; C08L23/02; C08L23/04; C08L23/06; C08L23/10; C08L23/12; C08L25/00; C08L25/02; C08L25/04; C08L25/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
An eraser comprising 15 to 40% by weight of a styrene thermoplastic elastomer as a matrix with 1 to 30 % by weight of a hydrocarbon resin which is a thermoplastic resin polymerized from chain hydrocarbon components or cyclic hydrocarbon components contained in petroleum, natural gas, natural rubbers or terpene oils and a polyolefin selected from the group consisting of polyethylene and polypropylene in a weight ratio of polyolefin to hydrocarbon resin of from 3/1 to 1/2 and from 25 to 60% by weight of an inorganic filler, said hydrocarbon resin, polyolefin and inorganic filler being contained in the matrix.
Claim 2
Dependent Claim
100 words
An eraser comprising 15 to 40% by weight of a styrene thermoplastic elastomer as a matrix with 1 to 30 % by weight of a hydrocarbon resin which is a thermoplastic resin polymerized from chain hydrocarbon components or cyclic hydrocarbon components contained in petroleum, natural gas, natural rubbers or terpene oils and a polyolefin selected from the group consisting of polyethylene and polypropylene in a weight ratio of polyolefin to hydrocarbon resin of from 3/1 to 1/2 and from 25 to 60% by weight of an inorganic filler, said hydrocarbon resin, polyolefin and inorganic filler being contained in the matrix.
Claim 3
Dependent Claim
33 words
An eraser according to claim 1, wherein said hydrocarbon resin is selected from the group consisting of terpene resins, hydrogenated terpene resins, aromatic petroleum resins, hydrogenated aromatic petroleum resins and aliphatic petroleum resins.
Claim 4
Dependent Claim
19 words
An eraser according to claim 1, wherein said hydrocarbon resin is a terpene resin or a hydrogenated terpene resin.
Claim 5
Dependent Claim
26 words
An eraser according to claim 1, wherein said thermoplastic elastomer is selected from the group consisting of styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-ethylene-butylene copolymers and styrene-ethylenepropylene copolymers.
Claim 6
Dependent Claim
20 words
An eraser according to claim 1, wherein said elastomer is contained in an amount of 25 to 50% by weight.
Claim 7
Dependent Claim
27 words
An eraser according to claim 1, wherein the weight ratio of total amount of the polyolefin and the hydrocarbon resin to the styrene thermoplastic elastomer is 1/10-6/10.
Claim 8
Dependent Claim
21 words
An eraser according to claim 1, wherein a softener is further contained in an amount of 1 to 15% by weight.
References Cited (Backward Citations)
US4305990A
Cited
US4418123A
Cited
US4374225A
Cited
US4386188A
Cited
US4721739A
Cited
US4578920A
Cited
US4743636A
Cited
US4761451A
Cited
US4753989A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |