CA1191993A - Furan resin binder for molding and core sands - Google Patents
Furan resin binder for molding and core sandsInfo
- Publication number
- CA1191993A CA1191993A CA000395928A CA395928A CA1191993A CA 1191993 A CA1191993 A CA 1191993A CA 000395928 A CA000395928 A CA 000395928A CA 395928 A CA395928 A CA 395928A CA 1191993 A CA1191993 A CA 1191993A
- Authority
- CA
- Canada
- Prior art keywords
- binder
- weight
- resin binder
- dry solids
- solids basis
- 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
-
- 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
- B22C1/26—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 carbohydrates; of distillation residues therefrom
-
- 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
- B22C1/224—Furan polymers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
- C08L61/34—Condensation polymers of aldehydes or ketones with monomers covered by at least two of the groups C08L61/04, C08L61/18 and C08L61/20
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Medicinal Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- Molecular Biology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Organic Chemistry (AREA)
- Polymers & Plastics (AREA)
- Mold Materials And Core Materials (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A resin-binder is provided that is especially useful for the preparation of foundry cores and molds. The novel resin binder which includes a sugar alcohol as an extender for the furfuryl alcohol in a urea, formaldehyde and furfuryl alcohol resin gives cores and molds with improved curing and strength properties over those formed with resins containing other furfuryl alcohol extenders.
A resin-binder is provided that is especially useful for the preparation of foundry cores and molds. The novel resin binder which includes a sugar alcohol as an extender for the furfuryl alcohol in a urea, formaldehyde and furfuryl alcohol resin gives cores and molds with improved curing and strength properties over those formed with resins containing other furfuryl alcohol extenders.
Description
~ 9 l 32~4 9 This invention relates to an improved furan resin binder useful for making foundry sand cores and molds 14 Binders or binder systems for foundry cores and molds are well known. Generally, such binders should provide cores 16 and molds which exhibit good thermal and dimensional stability 17 in order to produce good dimensionally accurate metal castings.
18 In addition, such binder systems should have rapid curing times 19 even under conditions of high relative humidity which often occur in the foundries.
22 In the foundry art, cores or-molds for making rnetal 23 castings are normally prepared from a mixture of an aggregake 24 material, such as sand, and a binding amount of a binder or binder system. Typically, after the aggregate material and 26 binder have been mixed, the resulting mixture is rammed, blown 28 or otherwise formed to the desired shape or patterns and then 1 cured with the use of catalysts and/or heat to a solid, cured
18 In addition, such binder systems should have rapid curing times 19 even under conditions of high relative humidity which often occur in the foundries.
22 In the foundry art, cores or-molds for making rnetal 23 castings are normally prepared from a mixture of an aggregake 24 material, such as sand, and a binding amount of a binder or binder system. Typically, after the aggregate material and 26 binder have been mixed, the resulting mixture is rammed, blown 28 or otherwise formed to the desired shape or patterns and then 1 cured with the use of catalysts and/or heat to a solid, cured
2 state.
4 A number of different processes for forming molds and cores have been developed in the foundry industry. One procedure 6 known as the "hot-box" process requires that the mixture of 7 aggregate material and binder be cured and hardened in a holding 8 pattern or core box while subjected to heat. Another method, 9 which does not require heating in order to bring about curing or hardening, is known as a "no-bake" process.
'11 12 Furan resin binders have been used in both the 13 "hot-box" and "no-bake" processes. Exempla-ry of such prior art 14 processes are U.S. Patents 3,168,490; 3~480,573; and 3,644,274.
16 Because of the relatively high cost of furfuryl 17 alcohol, various attempts have been made to replace part of 18 the furfuryl alcohol in these resins with less-expensive 19 materials. One such resin in which part of the furfuryl alcohol was replaced with either ethylene glycol or propylene 21 glycol was disclosed in British Patent Specification 1,492,821.
22 We have now discovered that part of the furfuryl alcohol in a 23 furan resin binder system can be replaced with a sugar alcohol.
24 These binders give cores and molds with superior properties to those prepared using resins containing glyccls as extenders.
26 This finding is particularly surprising in view of U.S. Patent 27 3,480,573 which states that sugar alcohols, such as sorbitol 28 and mannitol, are not very effective in such compositions.
4 A number of different processes for forming molds and cores have been developed in the foundry industry. One procedure 6 known as the "hot-box" process requires that the mixture of 7 aggregate material and binder be cured and hardened in a holding 8 pattern or core box while subjected to heat. Another method, 9 which does not require heating in order to bring about curing or hardening, is known as a "no-bake" process.
'11 12 Furan resin binders have been used in both the 13 "hot-box" and "no-bake" processes. Exempla-ry of such prior art 14 processes are U.S. Patents 3,168,490; 3~480,573; and 3,644,274.
16 Because of the relatively high cost of furfuryl 17 alcohol, various attempts have been made to replace part of 18 the furfuryl alcohol in these resins with less-expensive 19 materials. One such resin in which part of the furfuryl alcohol was replaced with either ethylene glycol or propylene 21 glycol was disclosed in British Patent Specification 1,492,821.
22 We have now discovered that part of the furfuryl alcohol in a 23 furan resin binder system can be replaced with a sugar alcohol.
24 These binders give cores and molds with superior properties to those prepared using resins containing glyccls as extenders.
26 This finding is particularly surprising in view of U.S. Patent 27 3,480,573 which states that sugar alcohols, such as sorbitol 28 and mannitol, are not very effective in such compositions.
3 I`t 1 SUMMARY OF THE IN~JENTIO~
3 In accordance with this invention, there is provided
3 In accordance with this invention, there is provided
4 a resin binder useful as a binder for foundry cores ar.d molds comprising urea, formaldehyde and furfuryl alcohol wherein the 6 improvement comprises replacing a sufficient part of the furfuryl 7 alcohol with a sugar alcohol to give a binder comprising from 8 about 0.2% to about 20% by weight of said sugar alcohol on a 9 dry solids basis.
.
13 The furan resins used for the practice of this 14 invention are those generally used as foundry resin binders except that part of the furfuryl alcohol has been replaced with 16 a sugar alcohol. The furan resins are generally mixtures of 17 urea, formaldehyde and furfuryl alcohol. The urea and 18 forma]dehyde can be reacted to give a precondensate before mixture 19 with the furfuryl alcohol. Alternatively, the furfuryl alcohol and the urea and formaldehyde can be used as precondensates as 21 is known in the foundry resin art. Silanes are usually added to 22 promote the adhesion of the resin to the foundry sand.
24 The arnount of furan resin binder used in the 25 manufacture of foundry cores and molds generally ranges from 26 about o.6% to about 2.5% of the weight of the sand and is 27 usually about 1% of the weight of the sand on a dry solids basis.
~3-. .. .
The furan resins of the present irvention are cured 2 with strong acids. Time of cure depends primarily on the type 3 of furan resin involved, on the climatic conditions (temperature ~ and air humidity) and on the strength of the acid used. Curing catalysts commonly employed are industrial-grade toluenesulfonic 6 acid or a mixture of isomers of ortho- and para-toluenesu]fonic .
7 acids, usually in the form of a 60-67% by weight aqueous 8 solution. Ortho-phosphoric acid of varying concentrations and 9 purities is used for this purpose as well.
10 .
11 The sugar alcohols used in the binder compositions of 12 this invention are those prepared by the hydrogenation of 13 monosaccharides and oligosaccharides. An example is the sugar 14 alcohol, sorbitol, obtained by hydrogenation of glucose.
. . .
16 The sugar alcohols used can also be mixtures obtained 17 by the hydrogenation of starch hydrolyzates or cellulose 18 hydrolyzates. These materials have the advantage of being 19 less expensive than the alcohols obtained by the hydrogenation 20 ` of a pure sugar.
22 Hydrogenated hydrolyzates contain varying amounts of 23 maltitol and.other maltooligitols. Although these higher 24 molecular weight sugar alcohols do not appear to interfere with the curing properties of resin binders, their presence may 26 cause separat:ion of binder components. For; this reason, it is 27. preferred that such hydrogenated hydrolyzates contain at least 3 _II_ .
. ' '.
1.91~3 1 about 70% sorbitol, prererably about 85% sorbitol and mos~
2 preferably about 93% sorbitol by weight on a dry solids basis.
4 ~ The amount of the sugar alcohol used in the furan resin binders of this inventi-on is preferably in the range of from 6 about 0.2 to about 20%, more preferably from about 1 to about 7 15%, and most preferably from about 3 to 8% of the weight of 8 the binder on a dry solids basis. The remainder of the binder 9 consists chiefly of furfuryl alcohol and urea-formaldehyde.
Preferably, the furfuryl alcohol is present in amounts of about 11 40 to about 95%, more preferably about 50 to about 90%, and 12 most preferably of about 60 to about 75% by weight of the 13 binder on a dry solids basis. The urea-formaldehyde is 14 present in amounts of preferably about 2 to about 67%, more preferably about 5 to about 45%, and most preferably from 16 about 15 to about 30% by weight of the binder on a dry solids 17 basis.
19 The resin binders of this invention may optionally contain further additives commonly used in such foundry binders.
21 These include adhesion promoters such as silanes. Furthermore, 22 small amounts of glycols,such as ethylene glycol, can be added 23 to prevent separation of the components, particularly when 24 appreciable arnounts of maltooligitols are present. Finally, the furan resin binders of the invention can contain up to 226 about 30% of water.
3o -5-!
I
1 1 The followin~ examples illustrate certain embodiments I of the present invention. ~nless otherwise stated, all 3 proportions and percentages are provided on the basis of weight.
.
13 The furan resins used for the practice of this 14 invention are those generally used as foundry resin binders except that part of the furfuryl alcohol has been replaced with 16 a sugar alcohol. The furan resins are generally mixtures of 17 urea, formaldehyde and furfuryl alcohol. The urea and 18 forma]dehyde can be reacted to give a precondensate before mixture 19 with the furfuryl alcohol. Alternatively, the furfuryl alcohol and the urea and formaldehyde can be used as precondensates as 21 is known in the foundry resin art. Silanes are usually added to 22 promote the adhesion of the resin to the foundry sand.
24 The arnount of furan resin binder used in the 25 manufacture of foundry cores and molds generally ranges from 26 about o.6% to about 2.5% of the weight of the sand and is 27 usually about 1% of the weight of the sand on a dry solids basis.
~3-. .. .
The furan resins of the present irvention are cured 2 with strong acids. Time of cure depends primarily on the type 3 of furan resin involved, on the climatic conditions (temperature ~ and air humidity) and on the strength of the acid used. Curing catalysts commonly employed are industrial-grade toluenesulfonic 6 acid or a mixture of isomers of ortho- and para-toluenesu]fonic .
7 acids, usually in the form of a 60-67% by weight aqueous 8 solution. Ortho-phosphoric acid of varying concentrations and 9 purities is used for this purpose as well.
10 .
11 The sugar alcohols used in the binder compositions of 12 this invention are those prepared by the hydrogenation of 13 monosaccharides and oligosaccharides. An example is the sugar 14 alcohol, sorbitol, obtained by hydrogenation of glucose.
. . .
16 The sugar alcohols used can also be mixtures obtained 17 by the hydrogenation of starch hydrolyzates or cellulose 18 hydrolyzates. These materials have the advantage of being 19 less expensive than the alcohols obtained by the hydrogenation 20 ` of a pure sugar.
22 Hydrogenated hydrolyzates contain varying amounts of 23 maltitol and.other maltooligitols. Although these higher 24 molecular weight sugar alcohols do not appear to interfere with the curing properties of resin binders, their presence may 26 cause separat:ion of binder components. For; this reason, it is 27. preferred that such hydrogenated hydrolyzates contain at least 3 _II_ .
. ' '.
1.91~3 1 about 70% sorbitol, prererably about 85% sorbitol and mos~
2 preferably about 93% sorbitol by weight on a dry solids basis.
4 ~ The amount of the sugar alcohol used in the furan resin binders of this inventi-on is preferably in the range of from 6 about 0.2 to about 20%, more preferably from about 1 to about 7 15%, and most preferably from about 3 to 8% of the weight of 8 the binder on a dry solids basis. The remainder of the binder 9 consists chiefly of furfuryl alcohol and urea-formaldehyde.
Preferably, the furfuryl alcohol is present in amounts of about 11 40 to about 95%, more preferably about 50 to about 90%, and 12 most preferably of about 60 to about 75% by weight of the 13 binder on a dry solids basis. The urea-formaldehyde is 14 present in amounts of preferably about 2 to about 67%, more preferably about 5 to about 45%, and most preferably from 16 about 15 to about 30% by weight of the binder on a dry solids 17 basis.
19 The resin binders of this invention may optionally contain further additives commonly used in such foundry binders.
21 These include adhesion promoters such as silanes. Furthermore, 22 small amounts of glycols,such as ethylene glycol, can be added 23 to prevent separation of the components, particularly when 24 appreciable arnounts of maltooligitols are present. Finally, the furan resin binders of the invention can contain up to 226 about 30% of water.
3o -5-!
I
1 1 The followin~ examples illustrate certain embodiments I of the present invention. ~nless otherwise stated, all 3 proportions and percentages are provided on the basis of weight.
5- EXAMPL S AND COMPARATIVE TESTS
7 A known, extender-free furan resin binder with khe -8 following composition is used as the reference product (Resin A):
9 . ' URECOLL 181 29.88%
11 Silane 0.12%
12 Furfuryl Alcohol - 70.00%
14 URECOLL 181 (a registered trademark of BASF) is a 70% .
aqueous solution of a urea/formaldehyde precondensate available 16 from BASF A.-G. It contains 18-19% nitrogen, 2-4% free 17 formaldehyde and has a viscosity at 20C of 5000-8000 mPa-s.
18 The reference product is compared with six extender-containing 19 furan resin binders of the invention and with six extender-containinz furan resin binders known to the art (Examples 21 1 to 6 and comparative resins 1 to 6). All resins have the 22 same silane content as Resln A; their other composi.tions are 23 given in Table I. They were prepared by mixing the urea/
225 formaldehyde with the other ingredients at ~oom temperature.
227 . . .
3 . -6 ~ .
, .' I .
1 ~TABLE I
2Cornposi~ion (% by weight) 3 .
4 Sorbitol Ethylene Glycol Furfuryl(70% A4ueo~ls(70% Aqueous Example No. - URECOLL 181 AlcoholSolution) Solution~____
7 A known, extender-free furan resin binder with khe -8 following composition is used as the reference product (Resin A):
9 . ' URECOLL 181 29.88%
11 Silane 0.12%
12 Furfuryl Alcohol - 70.00%
14 URECOLL 181 (a registered trademark of BASF) is a 70% .
aqueous solution of a urea/formaldehyde precondensate available 16 from BASF A.-G. It contains 18-19% nitrogen, 2-4% free 17 formaldehyde and has a viscosity at 20C of 5000-8000 mPa-s.
18 The reference product is compared with six extender-containing 19 furan resin binders of the invention and with six extender-containinz furan resin binders known to the art (Examples 21 1 to 6 and comparative resins 1 to 6). All resins have the 22 same silane content as Resln A; their other composi.tions are 23 given in Table I. They were prepared by mixing the urea/
225 formaldehyde with the other ingredients at ~oom temperature.
227 . . .
3 . -6 ~ .
, .' I .
1 ~TABLE I
2Cornposi~ion (% by weight) 3 .
4 Sorbitol Ethylene Glycol Furfuryl(70% A4ueo~ls(70% Aqueous Example No. - URECOLL 181 AlcoholSolution) Solution~____
6 1 29.8~ 67.5 2.5 --2 29.8 65.0 5.0 --
7 3 29.88 62.5 7.5 --4 28 8 67.5 3.58 --
8 - 5 27.74 65.0 7.14 --
9 6 26.67 62.5 10.71 Comparative Resin No.
11 1 29.8~3 67.5 -- 2.5 2 29.8~ 65.0 -- 5.0 12 3 29.88 62.5 7 5 4 28.8 67.5 -- 3.58 13 5 27.74 65.0 -- 7.14 14 6 26.67 62.5 -- 10.
16 Test cores were prepared by mixing quartz sand (H 32) 17 with 0.33% by weight of p-toluenesulfonic acid catalyst and 1%
18 by weight of resin binder and forming the mixture into the 19 desired shape. Bending strength was determined according to the method described in "Bindemittelpruefung"., VDG-Merkblatt P72 21 ("Binding Agent Test", ~ssociation of German Foundry Men -22 - Pamphlet P72)~ December 1971- Bending strengths of the test 23 specimens (in N/cm ) were measured after various cure times at 2Ll arnblent temperature. Results of tests performed on specimens cured at two di~ferent relative humidities are given in Tables 26 II and III.
29 .
3 ~ 7-.
,¦TABLE II
¦(Curing performed in the laboratory at temperatures up 3 to 22~C and approximately 40% relative air humidity) - Bending strength (N/cm ) after curing for 6 Furan Resin Binder1 hr 2 hr5 4 hrs 24 hrs 7 Resin A 115 . 170 210 280 8 (Reference Product) 9 Example 1 130 170 205 280 Comparative Test 1 85 150 190 265 11 Example 2 120 165 200 275 12 Comparative Test 2 55 130 175 240 13 Example 3 iO0 170 200 270 14 Comparative Test 3 40 115 160 215 Example 4 140 190 240 . 280 .
16 Comparative Test 4 100 150 195 260 17 Example 5 135 180 225 280 18 Comparative Test 5 65 130 180 238 19 Example 6 120 175 220 . 265 222l ~omparativest 6 40 120 165 210 24 ~
~26 I
29 ., . , , ' . '.
l I
li!
2 (Curing perforrned in the laboratory at temperatures up 3 to 22C and approximately 65% relative air humidity) 6 Furan Resin Binder l hr 2 hrs 4 hrs24 hrs _ __ __ _ _ 7 Resin A- lO l50 330 350 . 8 (Reference Product) 9 Example l l5 l65 350 360 Comparative Test l 5 l20 320 325 11 Example 2 20 l50 330 335 12 Comparative Test 2 -- 75 250 290 13 Example 3 l5 l30 300 330 14 Comparative Test 3 -- 45 200 275 Example 4 20 160 360 370 `
16 Comparative Test 4 5 95 290 3l5 17 Example 5 l5 140 340 355 18 Comparative Test 5 -- 45 l90 280 19 Example 6 lO l20 290 320 Comparative Test 6 -- 25 lO0 235 22It is obvious from these results that test specimens 23 prepared from furan resin binders of the invention containing 24 a 70~ aqueous sorbitol solution as an extender show curing rates and ultirnate mechanical strength equivalent to the extender-free 26 reference product. Their ultimate mechanical strength and 27 especially their curing properties are distlnctly superior to 3o _9_ . l !
il those of the specimens prepared using the comparative binders ~ 2 containing equivalent amounts of ethylene glycol.
4 Thus, it is apparent that there has been provided, in accordance with the invention, a resin binder for the 6 preparation of foundry cores and molds that fully satisfies 7 the objects, aims~ and advantages set forth above. While 8 the invention has been described in conjunction with specific 9 embodiments thereof, it is evident that many alternatlves, modifications, and variations will be apparent to those skilled 11 in the ark in light of the foregoing description. Accordingly, 12 it is intended to include all such alternatives, modifications, 13 and variations as set forth within the spirit and scope of the 16 ~ appen d claims.
19 . . .. .
2256 ' 3 ~ ``
11 1 29.8~3 67.5 -- 2.5 2 29.8~ 65.0 -- 5.0 12 3 29.88 62.5 7 5 4 28.8 67.5 -- 3.58 13 5 27.74 65.0 -- 7.14 14 6 26.67 62.5 -- 10.
16 Test cores were prepared by mixing quartz sand (H 32) 17 with 0.33% by weight of p-toluenesulfonic acid catalyst and 1%
18 by weight of resin binder and forming the mixture into the 19 desired shape. Bending strength was determined according to the method described in "Bindemittelpruefung"., VDG-Merkblatt P72 21 ("Binding Agent Test", ~ssociation of German Foundry Men -22 - Pamphlet P72)~ December 1971- Bending strengths of the test 23 specimens (in N/cm ) were measured after various cure times at 2Ll arnblent temperature. Results of tests performed on specimens cured at two di~ferent relative humidities are given in Tables 26 II and III.
29 .
3 ~ 7-.
,¦TABLE II
¦(Curing performed in the laboratory at temperatures up 3 to 22~C and approximately 40% relative air humidity) - Bending strength (N/cm ) after curing for 6 Furan Resin Binder1 hr 2 hr5 4 hrs 24 hrs 7 Resin A 115 . 170 210 280 8 (Reference Product) 9 Example 1 130 170 205 280 Comparative Test 1 85 150 190 265 11 Example 2 120 165 200 275 12 Comparative Test 2 55 130 175 240 13 Example 3 iO0 170 200 270 14 Comparative Test 3 40 115 160 215 Example 4 140 190 240 . 280 .
16 Comparative Test 4 100 150 195 260 17 Example 5 135 180 225 280 18 Comparative Test 5 65 130 180 238 19 Example 6 120 175 220 . 265 222l ~omparativest 6 40 120 165 210 24 ~
~26 I
29 ., . , , ' . '.
l I
li!
2 (Curing perforrned in the laboratory at temperatures up 3 to 22C and approximately 65% relative air humidity) 6 Furan Resin Binder l hr 2 hrs 4 hrs24 hrs _ __ __ _ _ 7 Resin A- lO l50 330 350 . 8 (Reference Product) 9 Example l l5 l65 350 360 Comparative Test l 5 l20 320 325 11 Example 2 20 l50 330 335 12 Comparative Test 2 -- 75 250 290 13 Example 3 l5 l30 300 330 14 Comparative Test 3 -- 45 200 275 Example 4 20 160 360 370 `
16 Comparative Test 4 5 95 290 3l5 17 Example 5 l5 140 340 355 18 Comparative Test 5 -- 45 l90 280 19 Example 6 lO l20 290 320 Comparative Test 6 -- 25 lO0 235 22It is obvious from these results that test specimens 23 prepared from furan resin binders of the invention containing 24 a 70~ aqueous sorbitol solution as an extender show curing rates and ultirnate mechanical strength equivalent to the extender-free 26 reference product. Their ultimate mechanical strength and 27 especially their curing properties are distlnctly superior to 3o _9_ . l !
il those of the specimens prepared using the comparative binders ~ 2 containing equivalent amounts of ethylene glycol.
4 Thus, it is apparent that there has been provided, in accordance with the invention, a resin binder for the 6 preparation of foundry cores and molds that fully satisfies 7 the objects, aims~ and advantages set forth above. While 8 the invention has been described in conjunction with specific 9 embodiments thereof, it is evident that many alternatlves, modifications, and variations will be apparent to those skilled 11 in the ark in light of the foregoing description. Accordingly, 12 it is intended to include all such alternatives, modifications, 13 and variations as set forth within the spirit and scope of the 16 ~ appen d claims.
19 . . .. .
2256 ' 3 ~ ``
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A resin binder useful as a binder for foundry cores and molds comprising urea, formaldehyde and furfuryl alcohol wherein the improvement comprises replacing a sufficient part of the furfuryl alcohol with a sugar alcohol to give a binder comprising from about 0.2% to about 20% by weight of said sugar alcohol on a dry solids basis.
2. The resin binder of claim 1 wherein the sugar alcohol comprises at least about 70% sorbitol by weight on-a dry solids basis.
3. The resin binder of claim 2 wherein the sugar alcohol comprises at least about 93% sorbitol by weight on a dry solids basis.
4. The,resin binder of claims 1, 2 or 3 wherein the sugar alcohol consists essentially of a hydrogenated starch or cellulose hydrolyzate.
5. The resin binder of claims 1, 2 or 3 wherein the binder comprises from about 3.0% to about 8.0% by weight of sugar alcohol on a dry solids basis.
6. The resin binder of claims 1, 2 or 3 wherein the urea, formaldehyde content is between about 2% and about 67% by weight on a dry solids basis and the furfuryl alcohol content is between about 30% and 95% by weight on a dry solids basis.
7. The resin binder of claims 1, 2 or 3 wherein the urea, formaldehyde content is between about 20% and about 30% by weight on a dry solids basis and the furfuryl alcohol content is between about 60% and 75% by weight on a dry solids basis.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3104763.7 | 1981-02-11 | ||
| DE3104763A DE3104763C2 (en) | 1981-02-11 | 1981-02-11 | Furan resin binder for foundry mold and core sand |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1191993A true CA1191993A (en) | 1985-08-13 |
Family
ID=6124527
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000395928A Expired CA1191993A (en) | 1981-02-11 | 1982-02-10 | Furan resin binder for molding and core sands |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0057934A1 (en) |
| JP (1) | JPS57152343A (en) |
| AR (1) | AR227082A1 (en) |
| BR (1) | BR8200574A (en) |
| CA (1) | CA1191993A (en) |
| DE (1) | DE3104763C2 (en) |
| ES (1) | ES509488A0 (en) |
| MX (1) | MX7579E (en) |
| ZA (1) | ZA82726B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1165506A (en) * | 1981-12-07 | 1984-04-17 | Ervin I. Szabo | Method of manufacturing a foundry mould mix containing binder components and mould binder components therefor |
| CN112368091A (en) * | 2018-08-16 | 2021-02-12 | 花王株式会社 | Binder composition for mold making |
| JP6627012B1 (en) * | 2018-08-24 | 2019-12-25 | 花王株式会社 | Binder composition for mold making |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1433942B2 (en) * | 1962-08-09 | 1970-05-06 | Corn Products Company, New York, N.Y. (V.St.A.) | Binders for foundry cores and molds |
| DE1433931A1 (en) * | 1963-03-20 | 1968-11-21 | Albertuswerke Gmbh | Core and foundry sand binders |
| US4070196A (en) * | 1975-09-15 | 1978-01-24 | Foseco International Limited | Binder compositions |
| FR2348771A1 (en) * | 1976-04-21 | 1977-11-18 | Roquette Freres | Sand mould and core binder contg. silicate - and non-reducing polyol release agent having at least two alcoholic hydroxyl gps. |
| GB1571277A (en) * | 1978-05-31 | 1980-07-09 | Tate & Lyle Ltd | Phenol formaldehydr resins |
| CH641699A5 (en) * | 1978-12-15 | 1984-03-15 | Gremolith Ag | Process for preparing an acid-hardening binder solution for foundry moulding materials |
-
1981
- 1981-02-11 DE DE3104763A patent/DE3104763C2/en not_active Expired
-
1982
- 1982-01-12 AR AR288098A patent/AR227082A1/en active
- 1982-02-03 BR BR8200574A patent/BR8200574A/en unknown
- 1982-02-03 MX MX829898U patent/MX7579E/en unknown
- 1982-02-04 ZA ZA82726A patent/ZA82726B/en unknown
- 1982-02-09 EP EP82100926A patent/EP0057934A1/en not_active Withdrawn
- 1982-02-10 ES ES509488A patent/ES509488A0/en active Granted
- 1982-02-10 JP JP57019036A patent/JPS57152343A/en active Pending
- 1982-02-10 CA CA000395928A patent/CA1191993A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0057934A1 (en) | 1982-08-18 |
| ZA82726B (en) | 1983-05-25 |
| DE3104763C2 (en) | 1985-09-05 |
| ES8301706A1 (en) | 1983-01-16 |
| JPS57152343A (en) | 1982-09-20 |
| DE3104763A1 (en) | 1982-09-23 |
| AR227082A1 (en) | 1982-09-15 |
| MX7579E (en) | 1989-11-23 |
| BR8200574A (en) | 1982-12-07 |
| ES509488A0 (en) | 1983-01-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |