CA1082833A - Foundry binders - Google Patents
Foundry bindersInfo
- Publication number
- CA1082833A CA1082833A CA287,225A CA287225A CA1082833A CA 1082833 A CA1082833 A CA 1082833A CA 287225 A CA287225 A CA 287225A CA 1082833 A CA1082833 A CA 1082833A
- Authority
- CA
- Canada
- Prior art keywords
- polyisocyanate
- polyol
- composition
- weight
- composition according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/30—Low-molecular-weight compounds
- C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
- C08G18/3203—Polyhydroxy compounds
- C08G18/3215—Polyhydroxy compounds containing aromatic groups or benzoquinone groups
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/22—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins
- B22C1/2233—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- B22C1/2273—Polyurethanes; Polyisocyanates
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
- C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
- C08G18/6666—Compounds of group C08G18/48 or C08G18/52
- C08G18/667—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38
- C08G18/6674—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/3203
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
- C08G18/72—Polyisocyanates or polyisothiocyanates
- C08G18/80—Masked polyisocyanates
- C08G18/8003—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen
- C08G18/8051—Masked polyisocyanates masked with compounds having at least two groups containing active hydrogen with compounds of C08G18/36
Abstract
ABSTRACT
A foundry composition for use in forming foundry moulds or cores comprises an aggregate mixed with a binder which includes a polyisocyanate, a polyfunctional phenol and an aliphatic polyol with the weight of the phenol exceeding that of the polyol. The composition may be used in a "cold -box" process.
A foundry composition for use in forming foundry moulds or cores comprises an aggregate mixed with a binder which includes a polyisocyanate, a polyfunctional phenol and an aliphatic polyol with the weight of the phenol exceeding that of the polyol. The composition may be used in a "cold -box" process.
Description
Th-is invent:ion relate~s lo a I`oundry composition from whLch f'oundry moulds or cores are to be formed.
In tJ.~S. Patent 3,925,29fi there is claimed a f`oundry blnder composition comprising a polyisocyanate and a bisphenol. In the process disclosed in the patent~
a foundry aggrregate is mixed wit}l a blnder, formed to the required shape and the mixture is then cured by passing triethylamine through the shaped mixture. We have found that the strength o~ cores formed by this method and using a binder comprising a polyisocyanate and bisphenol-A decreases over a period following curing and that this decrease in strength is such as to make the method unsuitable for foundry use.
We have further discovered that this disadvantage can be reduced or overcome by modifying the binder composition used in the method.
~, According to the invention there is provided a Poundry composition comprising a foundry aggregate~ a polyisocyanate, a polyfunctional phenol and an a~hatic polyol having more than two -OH groups, wherein the weigh-t of the phenol exceeds that of the polyol.
By a polyfunctional phenol is meant a substance having two or more-OH groups attached directly to carbon - atoms in the same aromatic ring or in respective aromatic rings ., .
:
~ ' ~082833 which are lilllced together. Lly an aliphatic polyol is meant a substance wherein -the -Oll groups are attached to aliphatic carbon a toms :LIl a molecule or chain.
~ [n tlle pret'erred cotllposition~ the p}lenol is bisphenol-~ the polyol is a polyether polyol and tlle weight of the polyol is witllin -the range 5% to 7% of the weight of tlle phenol.
:
The polyisocyanate is preferably modified by reacting some of the NC0 groups with a drying oil.
In one example of a me-thod of producing a foundry core which involves use of a binder composition in accordance with the inveIltioIl~ tllcre 19 mndc up a poly-hydroxy composition ha~ing the following composition by weight:
; bisphenol-A 50%
polyether polyol 3%
solvent 47~
To assist the process of dissolving the bisphenol-A~ the three constituents are warmed and stirred together until a clear solution is obtained.
The particular polyol used is a polyether polyol sold under the designation G 600 by Lankro Chemicals Limited of Eccles, England. The solvent used is 2-ethoxy ethylacetate.
'''' Qp - ~08283;~
, , A polyisocyanate modified by raw linseed oil is prepared in the following manner. A mixture of the polyisocyallate and linseed oil is heated to a temperature of`.lr)proxirnately ll~5C. for approximately ~ifteen minutes.
'Ille mix~llre is thon coolod arld a solvent Ls added. The amounts used are such that the proportions, by weight, in -the modified polyisocyanate solution are as follows:-polyisocyanate 670 5%raw linseed oil 22. 5%
solvent 10%
The polyisocyanate used is an aromatic polyiso-cyanate sold by I.C.I. Chemicals Limited, England under the designation EDP 6503. This is of the diphenyl methane di-isocyanate type. The linseed~oiL is supplied by British Oil and Cake Mills Limited. The solvent is a petroleum fraction sold by Esso Chemicals Limited under the designation Solvesso 100.
The polyhydroxy composition and the modified ~ polyisocyanate solution are mixed together with foundry sand, the weight of di-isocyanate solution being twice that of the polyhydroxy composition. The mixture is charged into a core box and formed to the required shape. A tertiary amine in a gaseous form is then passed through -the core box for a few seconds, after which the core box is purged by an inert gas. The core is then cured sufficiently for it to be removed from the core box.
Tlle binder may be rnixed with the sand by either a continuous mixing process or a batch mixing process, since thc mix-ture of binder and sand has a bench life under normal condi-tions of temperature and humidity Or a-t least one or two hours. The amount of binder used with a given weight of sand depends upon factors which include the required core streng-th and the character of the sand and may be similar to the amounts of known cold setting binders which are used in foundries at the present time.
We have found that~ with a binder comprising the particular polyhydroxy composition and modified poly-isocyanate solution described, the relationship between the weight of aliphatic polyol used and the weight of bisphenol-A has an important effect on the ability of the core to maintain or even increase`its strength over a period of several days following curing. The weight of aliphatic polyol is preferably within the range 5% to 7%
. .
of the weight of bisphenol-A and the optimum value is 60/o of the weight of bisphenol-A. The particular aliphatic polyhydroxy compound usedh~s an hydroxyl value of 280.
Various catalysts listed in the book "Polyurethanes: Chemistry and Technology" by Saunders and ~risch, published by Wiley in 1962 may be used to catalyse the reaction between the isocyanate and the polyhydroxy composition. Whilst it is convenient to pass through the shaped composition a gaseous catalyst, liquid and/or solid catalysts which are mixed in the composition before -the ' ~082833 - G -composition is shaped may be used.
Tho polyisocyanate rnay comprise di-and/or trL-L'~Itlctional isocyanates. Corrlmorcia:Lly available rnix-tures of' these may be used. Alternatively, polyisocyanates con-taining more than three functional groups may be used.
'' ' ' ~
In tJ.~S. Patent 3,925,29fi there is claimed a f`oundry blnder composition comprising a polyisocyanate and a bisphenol. In the process disclosed in the patent~
a foundry aggrregate is mixed wit}l a blnder, formed to the required shape and the mixture is then cured by passing triethylamine through the shaped mixture. We have found that the strength o~ cores formed by this method and using a binder comprising a polyisocyanate and bisphenol-A decreases over a period following curing and that this decrease in strength is such as to make the method unsuitable for foundry use.
We have further discovered that this disadvantage can be reduced or overcome by modifying the binder composition used in the method.
~, According to the invention there is provided a Poundry composition comprising a foundry aggregate~ a polyisocyanate, a polyfunctional phenol and an a~hatic polyol having more than two -OH groups, wherein the weigh-t of the phenol exceeds that of the polyol.
By a polyfunctional phenol is meant a substance having two or more-OH groups attached directly to carbon - atoms in the same aromatic ring or in respective aromatic rings ., .
:
~ ' ~082833 which are lilllced together. Lly an aliphatic polyol is meant a substance wherein -the -Oll groups are attached to aliphatic carbon a toms :LIl a molecule or chain.
~ [n tlle pret'erred cotllposition~ the p}lenol is bisphenol-~ the polyol is a polyether polyol and tlle weight of the polyol is witllin -the range 5% to 7% of the weight of tlle phenol.
:
The polyisocyanate is preferably modified by reacting some of the NC0 groups with a drying oil.
In one example of a me-thod of producing a foundry core which involves use of a binder composition in accordance with the inveIltioIl~ tllcre 19 mndc up a poly-hydroxy composition ha~ing the following composition by weight:
; bisphenol-A 50%
polyether polyol 3%
solvent 47~
To assist the process of dissolving the bisphenol-A~ the three constituents are warmed and stirred together until a clear solution is obtained.
The particular polyol used is a polyether polyol sold under the designation G 600 by Lankro Chemicals Limited of Eccles, England. The solvent used is 2-ethoxy ethylacetate.
'''' Qp - ~08283;~
, , A polyisocyanate modified by raw linseed oil is prepared in the following manner. A mixture of the polyisocyallate and linseed oil is heated to a temperature of`.lr)proxirnately ll~5C. for approximately ~ifteen minutes.
'Ille mix~llre is thon coolod arld a solvent Ls added. The amounts used are such that the proportions, by weight, in -the modified polyisocyanate solution are as follows:-polyisocyanate 670 5%raw linseed oil 22. 5%
solvent 10%
The polyisocyanate used is an aromatic polyiso-cyanate sold by I.C.I. Chemicals Limited, England under the designation EDP 6503. This is of the diphenyl methane di-isocyanate type. The linseed~oiL is supplied by British Oil and Cake Mills Limited. The solvent is a petroleum fraction sold by Esso Chemicals Limited under the designation Solvesso 100.
The polyhydroxy composition and the modified ~ polyisocyanate solution are mixed together with foundry sand, the weight of di-isocyanate solution being twice that of the polyhydroxy composition. The mixture is charged into a core box and formed to the required shape. A tertiary amine in a gaseous form is then passed through -the core box for a few seconds, after which the core box is purged by an inert gas. The core is then cured sufficiently for it to be removed from the core box.
Tlle binder may be rnixed with the sand by either a continuous mixing process or a batch mixing process, since thc mix-ture of binder and sand has a bench life under normal condi-tions of temperature and humidity Or a-t least one or two hours. The amount of binder used with a given weight of sand depends upon factors which include the required core streng-th and the character of the sand and may be similar to the amounts of known cold setting binders which are used in foundries at the present time.
We have found that~ with a binder comprising the particular polyhydroxy composition and modified poly-isocyanate solution described, the relationship between the weight of aliphatic polyol used and the weight of bisphenol-A has an important effect on the ability of the core to maintain or even increase`its strength over a period of several days following curing. The weight of aliphatic polyol is preferably within the range 5% to 7%
. .
of the weight of bisphenol-A and the optimum value is 60/o of the weight of bisphenol-A. The particular aliphatic polyhydroxy compound usedh~s an hydroxyl value of 280.
Various catalysts listed in the book "Polyurethanes: Chemistry and Technology" by Saunders and ~risch, published by Wiley in 1962 may be used to catalyse the reaction between the isocyanate and the polyhydroxy composition. Whilst it is convenient to pass through the shaped composition a gaseous catalyst, liquid and/or solid catalysts which are mixed in the composition before -the ' ~082833 - G -composition is shaped may be used.
Tho polyisocyanate rnay comprise di-and/or trL-L'~Itlctional isocyanates. Corrlmorcia:Lly available rnix-tures of' these may be used. Alternatively, polyisocyanates con-taining more than three functional groups may be used.
'' ' ' ~
Claims (7)
1. A foundry composition from which a foundry mould or core is formed, the composition comprising a foundry aggregate, a polyisocyanate, a polyfunctional phenol and an aliphatic polyol having more than two -OH groups, wherein the weight of the phenol exceeds that of the polyol.
2. A composition according to claim 1 wherein the phenoi is bisphenol A, the polyol is a polyether polyol and the weight of the polyol is within the range 5% to 7% of the weight of the phenol.
3. A composition according to claim 1 wherein the polyol is a polyether polyol.
4. A composition according to claim 1 wherein the polyisocyanate is an aromatic polyisocyanate.
5. A composition according to claim 1 or claim 2 wherein the polyisocyanate is modified with a drying oil.
6. A composition according to claim 1 or claim 2 wherein the polyisocyanate is an aromatic polyisocyanate.
7. A composition according to claim 1 or claim 2 wherein the polyisocyanate is an aromatic isocyanate and is modified by reaction with raw linseed oil.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB30608/77 | 1977-07-21 | ||
| GB30608/77A GB1601938A (en) | 1977-07-21 | 1977-07-21 | Foundry binders |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1082833A true CA1082833A (en) | 1980-07-29 |
Family
ID=10310329
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA287,225A Expired CA1082833A (en) | 1977-07-21 | 1977-09-21 | Foundry binders |
Country Status (5)
| Country | Link |
|---|---|
| US (2) | US4209428A (en) |
| BR (1) | BR7706747A (en) |
| CA (1) | CA1082833A (en) |
| GB (1) | GB1601938A (en) |
| MX (1) | MX148158A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0002898A1 (en) * | 1977-12-07 | 1979-07-11 | Fordath Limited | Method of producing a foundry core or mould involving the reaction of a polyisocyanate and a polyhidroxy composition, polyhidroxy composition for use in the method and foundry composition produced in the method |
| US4311620A (en) * | 1980-05-08 | 1982-01-19 | Hooker Chemicals & Plastics Corp. | Foundry aggregate binders and foundry compositions prepared therefrom |
| US4366266A (en) * | 1981-02-05 | 1982-12-28 | Valvoline Oil & Chemicals Ltd. | Binder compositions and process for making molded products therewith |
| DE3339174C3 (en) * | 1983-10-28 | 1995-06-01 | Schuiling Metall Chemie B V | Cold hardening polyurethane-based binder for foundry purposes |
| US4692479A (en) * | 1985-07-19 | 1987-09-08 | Ashland Oil, Inc. | Self-setting urethane adhesive paste system |
| US4698377A (en) * | 1986-09-26 | 1987-10-06 | Acme Resin Corporation | Binder compositions containing phenolic resins and esters of alkoxy acids |
| US5264535A (en) * | 1991-06-12 | 1993-11-23 | Acme Resin Corp. | Low free formaldehyde phenolic polyol formulation |
| US5189079A (en) * | 1991-06-12 | 1993-02-23 | Acme Resin Corp. | Low free formaldehyde phenolic polyol formulation |
| DK0746432T3 (en) * | 1992-09-08 | 2002-04-02 | Ashland Oil Inc | Castings containing a polyether polyol and their use |
| US20050250874A1 (en) * | 2004-05-04 | 2005-11-10 | Ha-International, Llc | Phenolic urethane foundry binder |
| CA2588127A1 (en) * | 2004-12-23 | 2006-07-06 | Dow Global Technologies Inc. | An isocyanate composition comprising a vegetable oil and composites therefrom |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2374136A (en) * | 1940-11-01 | 1945-04-17 | Du Pont | Catalytic reaction of isocyanates with organic compounds |
| US3255500A (en) * | 1965-02-01 | 1966-06-14 | Archer Daniels Midland Co | Foundry composition comprising sand, drying oil and polyisocyanate |
| US3403721A (en) * | 1966-06-13 | 1968-10-01 | Ashland Oil Inc | Tensile strengths of certain sand cores |
| US3429848A (en) * | 1966-08-01 | 1969-02-25 | Ashland Oil Inc | Foundry binder composition comprising benzylic ether resin,polyisocyanate,and tertiary amine |
| US3432457A (en) * | 1967-07-12 | 1969-03-11 | Ashland Oil Inc | Resinous composition comprising benzylic ether resin,polyisocyanate,and tertiary amine |
| GB1269202A (en) * | 1968-02-14 | 1972-04-06 | Fordath Ltd | Improvements in the production of cores for use in the production of metal castings |
| US3925296A (en) * | 1971-10-26 | 1975-12-09 | Hooker Chemicals Plastics Corp | Foundry aggregate binders |
| US3933727A (en) * | 1972-09-26 | 1976-01-20 | Ab Bofors | Method of producing polyurethane-based cores and moulds according to the so-called cold-box procedure |
-
1977
- 1977-07-21 GB GB30608/77A patent/GB1601938A/en not_active Expired
- 1977-09-21 CA CA287,225A patent/CA1082833A/en not_active Expired
- 1977-09-26 US US05/836,924 patent/US4209428A/en not_active Expired - Lifetime
- 1977-10-10 BR BR7706747A patent/BR7706747A/en unknown
-
1978
- 1978-01-31 MX MX172251A patent/MX148158A/en unknown
- 1978-12-19 US US05/971,128 patent/US4224201A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| MX148158A (en) | 1983-03-22 |
| US4209428A (en) | 1980-06-24 |
| BR7706747A (en) | 1978-08-08 |
| US4224201A (en) | 1980-09-23 |
| GB1601938A (en) | 1981-11-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |