US4269256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing mold
Assignee: Hitachi Ltd
•
Filing: 1979-09-17
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Granted: 1981-05-26
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Expires: 1999-09-17
Abstract
Abstract A mold with an increased compression strength and a good collapsibility is prepared with a good efficiency by mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of a copolymer containing a carboxyl group and calcium hydroxide, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO2 gas into the mold sand, thereby hardening the molding materials. Polyvinyl alcohol, calcium oxide, at least one hydroxide of zinc, aluminum, barium, magnesium, and iron, SBR latex, etc. can be added to the binder material, when desired.
Inventors
- 👤 Tetsuo Nakazawa
- 👤 Junji Sakai
- 👤 Syogo Morimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:23
CPC Classifications
B; B22; B22C; B22C1/00; B22C1/16; B22C1/162
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
78 words
A process for perparing a mold by hardening molding materials by CO 2 gas which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, and calcium hydroxide, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
Claim 2
Dependent Claim
78 words
A process for perparing a mold by hardening molding materials by CO 2 gas which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, and calcium hydroxide, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
Claim 3
Dependent Claim
28 words
A process according to claim 1, wherein 0.2-2.0 parts by weight of the copolymer as solid matters is added to 100 parts by weight of the refractory particles.
Claim 4
Dependent Claim
26 words
A process according to claim 1, wherein 0.2-4.0 parts by weight of the calcium hydroxide is added to 100 parts by weight of the refractory particles.
Claim 5
Dependent Claim
37 words
A process according to claim 1, wherein 0.2-2.0 parts by weight of the copolymer as solid matters and 0.2-4.0 parts by weight of the calcium hydroxide are added to 100 parts by weight of the refractory particles.
Claim 6
Dependent Claim
80 words
A process for preparing a mold by hardening molding materials by CO 2 gas, which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, calcium hydroxide, and polyvinyl alcohol, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
Claim 7
Dependent Claim
80 words
A process for preparing a mold by hardening molding materials by CO 2 gas, which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, calcium hydroxide, and polyvinyl alcohol, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
Claim 8
Dependent Claim
29 words
A process according to claim 5, wherein not more than 2 parts by weight of the polyvinyl alcohol is added to 100 parts by weight of the refractory particles.
Claim 9
Dependent Claim
99 words
A process for preparing a mold by hardening molding materials by CO 2 gas, which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, calcium hydroxide, and at least one member selected from the group consisting of calcium oxide and hydroxides of zinc, aluminum, barium, magnesium and iron, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
Claim 10
Dependent Claim
99 words
A process for preparing a mold by hardening molding materials by CO 2 gas, which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, calcium hydroxide, and at least one member selected from the group consisting of calcium oxide and hydroxides of zinc, aluminum, barium, magnesium and iron, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
Claim 11
Dependent Claim
82 words
A process for preparing a mold by hardening molding materials by CO 2 gas, which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, calcium hydroxide, and SBR styrene-butadiene rubber latex, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
Claim 12
Dependent Claim
82 words
A process for preparing a mold by hardening molding materials by CO 2 gas, which comprises mixing refractory particles with a binder material comprising a caustic alkali-neutralized product of at least one copolymer selected from the group consisting of α-olefin-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and methylvinyl ether-maleic anhydride copolymer, calcium hydroxide, and SBR styrene-butadiene rubber latex, thereby preparing molding materials, filling the molding materials around a pattern, and blowing CO 2 gas into the molding materials, thereby hardening the molding materials.
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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) | 1984-05-25 | 1984-11-24 | 1985-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-25 | 1988-11-24 | 1989-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-25 | 1992-11-24 | 1993-05-26 | $7700.00 | Window Closed / Lapsed |