Patent US3923304A successfully refreshed from Google Patents.
US4097443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing foundry molds
Assignee: Sumitomo Durez Co Ltd
•
Filing: 1975-10-30
•
Granted: 1978-06-27
•
Expires: 1995-10-30
Abstract
Abstract A method for manufacturing foundry molds, which comprises preforming a foundry sand mixture comprising sand, a resol type phenol-formaldehyde resin, a solvent, and optionally, a curing agent for said resin, or a curing agent for said resin and a thermoplastic resin; and thereafter removing the solvent from the preformed mixture by evaporation.
Inventors
- 👤 Masayuki Nakamura
- 👤 Setsuo Sanuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:54
CPC Classifications
C; C08; C08L; C08L61/00; C08L61/04; C08L61/06; B; B22; B22C; B22C1/00; B22C1/16; B22C1/20; B22C1/22; B22C1/2233; B22C1/2246; B22C1/2253
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
119 words
A self-curing process for manufacturing foundry sand cores and molds which comprises preforming a mixture consisting essentially of the sand, resin consisting essentially of a phenol-formaldehyde resol resin and a volatile organic solvent for said resol resin selected from the group consisting of methanol, ethanol, propanol, acetone, methylethyl ketone, diacetone, ethyl acetate, butyl acetate, and mixtures thereof, the amount of resin being about 0.5 to 3 weight percent based on the weight of sand and the amount of solvent being about 0.2 to about 7 weight percent based on the weight of sand and evaporating the solvent from said preformed mixture at about 20° C. to about 50° C. to harden the resin and obtain the foundry mold composition.
Claim 2
Dependent Claim
119 words
A self-curing process for manufacturing foundry sand cores and molds which comprises preforming a mixture consisting essentially of the sand, resin consisting essentially of a phenol-formaldehyde resol resin and a volatile organic solvent for said resol resin selected from the group consisting of methanol, ethanol, propanol, acetone, methylethyl ketone, diacetone, ethyl acetate, butyl acetate, and mixtures thereof, the amount of resin being about 0.5 to 3 weight percent based on the weight of sand and the amount of solvent being about 0.2 to about 7 weight percent based on the weight of sand and evaporating the solvent from said preformed mixture at about 20° C. to about 50° C. to harden the resin and obtain the foundry mold composition.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the preformed mixture also contains a curing amount of a curing agent for said resol resin.
Claim 4
Dependent Claim
32 words
The process of claim 2 wherein the resin component of preformed mixture also contains up to about 2.75 weight percent of an organic thermoplastic resin based on the weight of the sand.
Claim 5
Dependent Claim
20 words
The process of claim 2 wherein the solvent is selected from the group consisting of methanol, butyl acetate and acetone.
Claim 6
Dependent Claim
25 words
The process of claim 2 wherein the curing agent is selected from the group consisting of para-toluene sulfonic acid, benzene sulfonic acid and phosphoric acid.
Claim 7
Dependent Claim
27 words
The process as claimed in claim 5 wherein the amount of curing agent is about 0.0075 to about 0.45 weight percent based on the weight of sand.
Claim 8
Dependent Claim
18 words
The process as claimed in claim 1 wherein the resol resin is a substantially anhydrous phenol-formaldehyde resol resin.
Claim 9
Dependent Claim
30 words
The process as claimed in claim 1 wherein the solvent is evaporated from the preformed mixture under a subatmospheric pressure at a temperature of about 20° to about 50° Centigrade.
Claim 10
Dependent Claim
48 words
The process as claimed in claim 1 wherein the solvent is evaporated from the preformed mixture by passing a stream of inert gas through the preformed mixture at a pressure of about 0.2 to about 5 kg/cm 2 and a temperature of about 20° to about 50° Centigrade.
References Cited (Backward Citations)
US1989243A
Cited
US2806832A
Cited
US2915491A
Cited
US3433701A
Cited
US3432457A
Cited
US3551365A
Cited
US3720642A
Cited
US3676392A
Cited
US3943089A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |