Phenolic resin-polyisocyanate binder systems containing an organohalophosphate and use thereof

A binder containing a phenolic resin, a polyisocyanate, and an organohalophosphate and use thereof.

DESCRIPTION 
1. Technical Field 
The present invention relates to binder compositions, methods for curing 
such binder compositions, and use thereof. The binder compositions of the 
present invention are especially useful as molding compositions such as 
refractories, abrasive articles, and molding shapes such as cores and 
molds. The preferred binder compositions of the present invention are 
especially useful in obtaining aggregate-binder compositions that exhibit 
improved bench life. The binder compositions are capable of being cured at 
room temperature by a gaseous curing agent. 
2. Background Art 
U.S. Pat. Nos. 3,409,579 and 3,676,392 disclose binder compositions made 
available as two-package systems comprising a resin component in one 
package and a hardener component in the other package. The resin component 
comprises an organic solvent solution of a phenolic resin. The hardener 
component comprises a liquid polyisocyanate having at least two isocyanate 
groups per molecule. At the same time the contents of the two packages are 
combined and then mixed with the sand aggregate or preferably the packages 
are sequentially admixed with sand aggregate. After a uniform distribution 
of the binder on the sand particles has been obtained, the resulting 
foundry mix is molded into the desired shape. In U.S. Pat. No. 3,409,579 
the molded shape is cured by passing a gaseous tertiary amine through it. 
In U.S. Pat. No. 3,676,392 curing is effected by means of a base having a 
pKb value in the range of about 7 to about 11 as determined by a method 
described by D. D. Perrin in "Dissociation Constants of Organic Bases in 
Aqueous Solution", Butterworths, London, 1965. The base is introduced 
originally into the resin component before it is mixed with hardener, or 
it may be introduced as the third component of a three-package binder 
system comprising in separate packages the resin component, the hardener, 
and the base. 
In both U.S. Pat. Nos. 3,409,579 and 3,676,392 the preferred phenolic 
resins and benzylic ether resins. These are the condensation products of a 
phenol having the general formula: 
##STR1## 
wherein A, B, and C are hydrogen, hydrocarbon radicals, oxyhydrocarbon 
radicals, or halogen with an aldehyde having the general formula R'CHO 
wherein R' is a hydrogen or a hydrocarbon radical of 1 to 8 carbon atoms, 
prepared in the liquid phase under substantially anhydrous conditions at 
temperatures below about 130.degree. C. in the presence of catalytic 
concentrations of a metal ion dissolved in the reaction medium. The 
preparation and characterization of these resins is disclosed in greater 
detail in U.S. Pat. No. 3,485,797. 
The phenolic resin component of the binder composition is, as indicated 
above, generally employed as a solution in an organic solvent. 
The second component or package of the binder composition comprises an 
aliphatic, cycloaliphatic, or aromatic polyisocyanate having preferably 
from 2 to 5 isocyanate groups. If desired, mixtures of polyisocyanates can 
be employed. Isocyanate prepolymers formed by reacting excess 
polyisocyanate with a polyhydric alcohol (e.g., a prepolymer of toluene 
diisocyanate and ethylene glycol) can be employed. 
Suitable polyisocyanates include the aliphatic polyisocyanates such as 
hexamethylene diisocyanate, alicyclic polyisocyanates such as 
4,4'-dicyclohexylmethane diisocyanate, and aromatic polyisocyanates such 
as 2,4' and 2,6-toluene diisocyanate, diphenylmethane diisocyanate, and 
dimethyl derivatives thereof. Further examples of suitable polyisocyanates 
are 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, xylylene 
diisocyanate, and the methyl derivatives thereof, polymethylenepolypehnyl 
isocyanates, chlorophenylene-2, 4-diisocyanate, and the like. The 
polyisocyanate is employed in sufficient concentrations to cause the 
curing of the phenolic resin. In general, the polyisocyanate will be 
employed in a range of 10 to 500 weight percent of polyisocyanate based on 
the weight of the phenolic resin. Preferably, from 20 to 300 weight 
percent of polyisocyanate on the same basis is employed. The 
polyisocyanate is employed in liquid form. Liquid polyisocyanates can be 
employed in undiluted form. Solid or viscous polyisocyanates are employed 
in the form of organic solvent solutions, the solvent being present in a 
range of up to 80% by weight of the solution. 
In order to extend the bench life of the above binder systems before being 
combined with the catalytic component various materials have been 
suggested. One material currently being commercially employed for such 
purpose is phthaloyl chloride. However, it is not entirely satisfactory. 
The bench life can be defined as the maximum permissible time delay 
between mixing the binder components together in sand and the production 
of acceptable products therefrom. Other bench life extenders are suggested 
in U.S. Pat. Nos. 4,436,881; 4,514,316; and 4,540,724. In particular, U.S. 
Pat. Nos. 4,436,881 and 4,514,316 discuss the use of certain 
dichloroarylphosphines, chlorodiarylphosphines, arylphosphonic 
dichlorides, and diarylphosphinyl chlorides for such purposes. U.S. Pat. 
No. 4,540,724 discloses the use of inorganic phosphorus halides and of 
certain organic phosphorus halides and especially phenyl phosphonic 
dichloride and benzene phosphorus dichloride as bench life extenders. 
DESCRIPTION OF INVENTION 
The bench life of the molding compositions is extended according to the 
present invention by employing organohalophosphates. In addition, the 
compositions exhibit satisfactory strength characteristics. 
The present invention is concerned with a binder composition which 
comprises a resin component, a hardener component, a curing component, and 
an organohalophosphate. The resin component includes a non-aqueous 
phenolic resin which comprises a condensation product of a phenol with an 
aldehyde. For instance, the phenol can be represented by the formula: 
##STR2## 
wherein A, B, and C are hydrogen, or hydroxyl, or hydrocarbon radicals, or 
halogen, or combinations thereof. 
The aldehyde has the formula R'CHO wherein R' is a hydrogen or hydrocarbon 
radical of 1 to 8 carbon atoms. The hardener component comprises liquid 
polyisocyanate containing at least two isocyanate groups. 
The present invention is also concerned with molding compositions which 
comprise a major amount of aggregate and an effective bonding amount up to 
about 40% by weight of the aggregate of the binder composition described 
hereinabove. 
Moreover, the present invention is concerned with fabricating foundry 
shapes which comprises mixing foundry aggregate with a bonding amount of 
up to about 10% by weight based upon the weight of the aggregate of the 
binder composition described hereinabove. The foundry mix is introduced in 
a pattern and hardened to become self-supporting. The shaped foundry mix 
is removed from the pattern and allowed to further cure to thereby obtain 
a hard, solid, cured foundry shape. 
Furthermore, the present invention is concerned with a process for casting 
a metal. The process comprises fabricating a foundry shape as discussed 
hereinabove and pouring the metal while in the liquid or molten state into 
or around the shape. The metal is allowed to cool and solidify and is then 
separated from the molded article. 
BEST AND VARIOUS MODES FOR CARRYING OUT THE INVENTION 
The organohalophosphates employed according to the present invention are 
represented by the following structural formulae: 
##STR3## 
n is 0 or 1; m is 0 or 1 provided that at least one of n or m is 1; and 
n+m is 1 or 2; 
##STR4## 
r is 0 or 1 and s is 0 or 1; and wherein each R and R.sup.1 in formula I 
individually is alkyl, aralkyl, aryl, or alkaryl or interconnected with 
each other to form an arylene group, an alkylene group, or a cycloalkylene 
group. 
Each R.sup.3 and R.sup.4 in formula II individually is alkyl, aralkyl, 
aryl, or alkaryl. 
R.sup.2 in formula II is alkylene, alkylidene, cycloalkylene, or arylene. 
The alkyl groups (R, R.sup.1, R.sup.3, and R.sup.4) usually has from 1 to 
22 carbon atoms and preferably from 1 to 6 carbon atoms and includes 
methyl, ethyl, propyl, and butyl. 
The aryl groups (R, R.sup.1, R.sup.3, and R.sup.4) usually contain 6 to 14 
carbon atoms. Examples of some aryl groups are phenyl and naphthyl. 
The aralkyl group and alkaryl groups (R, R.sup.1, R.sup.3, and R.sup.4) 
usually include 6 to 14 carbon atoms in the aryl portion and about 1 to 22 
carbon atoms in the alkyl portion and preferably about 1 to 6 carbon atoms 
in the alkyl portion. 
The alkyl, aryl, alkaryl, and aralkyl groups can be substituted with 
halogen atoms, if desired. 
When R.sup.1 and R in formula I are interconnected to form an arylene group 
such group usually contains 6 to 14 carbon atoms and includes phenylene, 
naphthalene, and biphenylene. 
When R.sup.1 and R in Formula I are interconnected to form an alkylene 
group such group usually contains two to four carbon atoms such as 
ethylene, propylene, and butylene. 
When R.sup.1 and R in formula I are interconnected to form a cycloalkylene 
group such group usually includes 5 or 6 carbon atoms such as 
cyclohexylene and cyclopentylene. 
The arylene groups (R.sup.2) in formula II usually contain 6 to 14 carbon 
atoms such as phenylene, naphthalene, and biphenylene. 
The alkylene and alkylidene groups (R.sup.2) in formula II usually contain 
1 to about 6 carbon atoms and include methylene, ethylene, ethylidene, 
propylene, propylidene, butylene, and neopentylene. 
The cycloalkylene group R.sup.2 in formula II usually contains 5 or 6 
carbon atoms and includes cyclopentylene and cyclohexylene. 
The arylene groups, alkylene groups, alkylidene groups, and cycloalkylene 
groups can be substituted with halogen atoms, if desired. 
X in the above formula is a halo group, preferably Cl. or Br and most 
preferably Cl. 
Examples of some specific organohalophosphates are 
##STR5## 
The amount of organohalophosphates employed is usually about 0.05% to about 
5% based upon the weight of the binder composition and preferably about 
0.1% to about 5% based upon the weight of the binder. 
The binder compositions which are benefited by use of this invention are 
known to the art and are those which contain certain phenolic resin and 
polyisocyanate combinations. 
Such phenolic/isocyanate binder systems are admixed at or about the time of 
use in the presence of sand. 
Typically, the reactive ingredients of such binder compositions are sold, 
shipped, and stored in separate packages (i.e., a multiple package core 
binder) to avoid undesirable deterioration due to premature reaction 
between the components. Solvents, catalysts, various additives, and other 
known binders can optionally be used in conjunction with these essential 
ingredients (i.e., used with the phenolic resin and the isocyanate). 
The phenol resin component includes a phenolic resin which comprises 
reaction products of a phenol with an The phenol resin component includes 
a phenolic resin which comprises reaction products of a phenol with an 
aldehyde. 
The phenol can be represented by the general formula: 
##STR6## 
wherein A, B, and C are hydrogen atoms, or hydroxyl radicals, or 
hydrocarbon radicals or oxyhydrocarbon radicals, or halogen atoms, or 
combinations of these. 
This phenol may be a multiple ring phenol such as bisphenol A. The phenolic 
resin is preferably non-aqueous. By "non-aqueous" is meant a phenolic 
resin which contains water in amounts of no more than about 10%, 
preferably no more than about 5%, and more preferably no more than about 
1% based on the weight of the resin. The phenolic resin component 
preferably includes benzylic ether resins. 
The aldehyde has the formula R'CHO wherein R' is a hydrogen or hydrocarbon 
radical of 1 to 8 carbon atoms. 
By "phenolic resin" is meant the reaction product of a phenol with an 
aldehyde in which the final mixture of molecules in the reaction products 
is dependent upon the specific reactants selected, the starting ratio of 
these reactants, and the conditions of the reaction (for example, the type 
of catalyst, the time and temperature of the reaction, the solvents, 
and/or other ingredients present, and so forth). The reaction products, 
that is the phenolic resin, will be a mixture of different molecules and 
may contain in widely varying ratios addition products, condensation 
products, and unreacted reactants such as unreacted phenol and/or 
unreacted aldehyde. 
By "addition product" is meant reaction products in which an organic group 
has been substituted for at least one hydrogen of a previously unreacted 
phenol or of a condensation product. 
By "condensation product" is meant reaction products that link two or more 
aromatic rings. 
The phenolic resins are substantially free of water and are organic solvent 
soluble. The phenolic component includes any one or more of the phenols 
which have heretofore been employed in the formation of phenolic resins 
and which are not substituted at either the two ortho-positions or at one 
ortho-position and the para-position such as unsubstituted positions being 
necessary for the polymerization reaction. Any one, all, or none of the 
remaining carbon atoms of the phenol ring can be substituted. The nature 
of the substituent can vary widely and it is only necessary that the 
substituent not interfere in the polymerization of the aldehyde with the 
phenol at the ortho-position and/or para-position. Substituted phenols 
employed in the formation of the phenolic resins include alkyl-substituted 
phenols, aryl-substituted phenols, cyclo-alkyl-substituted phenols, 
aryloxy-substituted phenols, and halogen-substituted phenols, the 
foregoing substituents containing from 1 to 26 carbon atoms and preferably 
from 1 to 12 carbon atoms. 
Specific examples of suitable phenols include phenol, 2,6-xylenol, 
o-cresol, m-cresol, p-cresol, 3,5-xylenol, 3,4-xylenol, 2,3,4-trimethyl 
phenol, 3-ethyl phenol, 3,5-diethyl phenol, p-butyl phenol, 3,5-dibutyl 
phenol, p-amyl phenol, p-cyclohexyl phenol, p-octyl phenol, 
3,5-dicyclohexyl phenol, p-phenyl phenol, p-crotyl phenol, 3,5-dimethoxy 
phenol, 3,4,5-trimethoxy phenol, p-ethoxy phenol, p-butoxy phenol, 
3-methyl-4-methoxy phenol, and p-phenoxy phenol. Multiple ring phenols 
such as bisphenol A are also suitable. Such phenols can be described by 
the general formula: 
##STR7## 
wherein A, B, and C are hydrogen atoms, or hydroxyl radicals, or 
hydrocarbon radicals, or oxyhydrocarbon radicals, or halogen atoms, or 
combinations of these. 
The phenol component is preferably reacted with an aldehyde to form 
phenolic resins and more preferably benzylic ether resins. The aldehydes 
reacted with the phenol can include any of the aldehydes heretofore 
employed in the formation of phenolic resins such as formaldehyde, 
acetaldehyde, propionaldehyde, furfuraldehyde, and benzaldehyde. In 
general, the aldehydes employed have the formula R'CHO wherein R' is a 
hydrogen or a hydrocarbon radical of 1 to 8 carbon atoms. The most 
preferred aldehyde is formaldehyde. 
A preferred class of phenolic resins that can be employed in the binder 
compositions of the present invention is described in U.S. Pat. No. 
3,485,797 referred to above. The phenolic resins employed in the binder 
compositions also can include either resole or A-stage resins or novolak 
resins when admixed with polyisocyanates and a foundry aggregate and cured 
by use of catalysts, these resins form cores of sufficient strength and 
other properties to be suitable in industrial applications. The resole 
resins are preferred over the novolak resins. The resole or B-stage resins 
which are a more highly polymerized form of resole resins are generally 
unsuitable. The phenolic resin employed must be liquid or organic 
solvent-suitable. Solubility in organic solvent is desirable to achieve 
uniform distribution of the binder on the aggregate. 
The substantial absence of water in the phenolic resin is desirable in view 
of the reactivity of the binder composition of the present invention with 
water. Mixtures of phenolic resins can be used. 
The phenolic resin component of the binder composition is, as indicated 
above, generally employed as a solution in an organic solvent. The nature 
and the effect of the solvent will be more specifically described below. 
The amount of solvent used should be sufficient to result in a binder 
composition permitting uniform coating thereof on the aggregate and 
uniform reaction of the mixture. The specific solvent concentration for 
the phenolic resins will vary depending on the type of phenolic resins 
employed and its molecular weight. In general, the solvent concentration 
will be in the range of up to 80% by weight of the resin solution and 
preferably in the range of 20% to 80%. It is preferred to keep the 
viscosity of the phenolic component at less than X-1 on the Gardner-Holt 
Scale. 
The second component or package of the binder composition comprises an 
aliphatic, cycloaliphatic, or aromatic polyisocyanate having preferably 
from 2 to 5 isocyanate groups. If desired, mixtures of organic 
polyisocyanates can be employed. Suitable polyisocyanates include the 
aliphatic polyisocyanates such as 4,4'-dicyclohexylmethane diisocyanate 
and the dimethyl derivatives thereof. Further examples of suitable 
polyisocyanates are 1,5-naphthalene diisocyanate, triphenylmethane 
triisocyanate, xylylene diisocyanate, and the methyl derivatives thereof; 
polymethylenepolyphenyl isocyanates, chlorophenylene-2,4-diisocyanate, and 
the like. Mixtures of isocyanates can be used. 
The polyisocyanate is employed in sufficient concentrations to cause the 
curing of the phenolic resin. In general, the polyisocyanate will be 
employed in a range of 10 to 500 weight percent of polyisocyanate based on 
the weight of the phenolic resin. Preferably, from 20 to 300 weight 
percent of polyisocyanate on the same basis is employed. The 
polyisocyanate is employed in liquid form. Liquid polyisocyanates can be 
employed in undiluted form. Solid or viscous polyisocyanates are employed 
in the form of organic solvent solutions, the solvent being present in a 
range of up to 80% by weight of the solution. Most preferably, the 
isocyanate is employed in a stoichiometric amount .+-. about 20% based on 
the available hydroxyl groups of the phenolic resin. 
The difference in the polarity between the polyisocyanate and the phenolic 
resins restricts the choice of solvents in which both components are 
compatible. Such compatibility is necessary to achieve complete reaction 
and curing of the binder compositions of the present invention. Polar 
solvents of either the protic or aprotic type are good solvents for the 
phenolic resin, but have limited compatibility with the polyisocyanates. 
Aromatic solvents, although compatible with the polyisocyanates, are less 
compatible with the phenolic resins. It is, therefore, preferred to employ 
combinations of solvents and particularly combinations of aromatic and 
polar solvents. Suitable aromatic solvents are benzene, toluene, xylene, 
ethylbenzene, and mixtures thereof. Preferred aromatic solvents are mixed 
solvents that have an aromatic content of at least 90% and a boiling point 
range of 280.degree. F. to 450.degree. F. 
The polar solvents should not be extremely polar such as to become 
incompatible with the aromatic solvent. 
Suitable polar solvents are generally those which have been classified in 
the art as coupling solvents and include furfural, furfuryl alcohol, 
Cellosolve acetate, butyl Cellosolve, butyl Carbitol, diacetone alcohol, 
and "Texanol". 
In addition, the compositions can include drying oils such as disclosed in 
U.S. Pat. No. 4,268,425. Such drying oils include glycerides of fatty 
acids which contain two or more double bonds whereby oxygen on exposure to 
air can be absorbed to give peroxides which catalyze the polymerization of 
the unsaturated portions. 
Examples of some natural drying oils include soybean oil, sunflower oil, 
hemp oil, linseed oil, tung oil, oiticia oil, and fish oils, and 
dehydrated castor oil, as well as the various known modifications thereof 
(e.g., the heat bodied, air-blown, or oxygen-blown oils such as blown 
linseed oil and blown soybean oil). The above discussion concerning the 
oil is not intended to imply that such actually cure in the present system 
by air drying, but is intended to help define the drying oils. 
Also, esters of ethylenically unsaturated fatty acids such as tall oil 
esters of polyhydric alcohols such as glycerine or pentaerythritol or 
monohydric alcohols such as methyl and ethyl alcohols can be employed as 
the drying oil. If desired, mixtures of drying oils can be employed. The 
preferred drying oil employed in the present invention is linseed oil. 
The amount of drying oil employed is generally at least about 2%, 
preferably about 2% to about 15%, and most preferably about 4% to about 
10% by weight based upon the total of the components in the binder 
composition. The drying oil can be considered part of the solvent 
component of the composition. 
In addition, the solvent component can include liquid dialkyl ester such as 
dialkyl phthalate of the type disclosed in U.S. Pat. No. 3.905,934. Such 
preferably have the structure: 
##STR8## 
where R.sup.1 and R.sup.2 are alkyl radicals of 1 to 12 carbon atoms and 
the total number of carbon atoms in the R groups does not exceed 16. 
Preferably, R.sup.1 and R.sup.2 are alkyl radicals of 3 to 6 carbon atoms 
and the total number of carbon atoms in R.sup.1 and R.sup.2 is between 6 
and 12. Thus, in the above structural formula either R group can be 
methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, 
isopentyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl, and other 
isomers of the foregoing. 
Other dialkyl esters include dimethyl glutarate such as available from Du 
Pont under the trade designation DBE-5; dimethyl adipate, available from 
Du Pont under the trade designation DBE-6; dimethyl succinate; and 
mixtures of such esters which are available from Du Pont under the trade 
designation DBE, and dialkyl adipates and succinates with alcohols up to 
12 carbon atoms. 
The binder compositions are preferably to be made available as a 
two-package system with the phenolic resin in one package and the 
isocyanate component in the other package with the drying oil. Usually, 
the binder components are combined and then admixed with sand or a similar 
aggregate to form the molding mix or the mix can also be formed by 
sequentially admixing the components with the aggregate. Methods of 
distributing the binder on the aggregate particles are well-known to those 
skilled in the art. The mix can, optionally, contain other ingredients 
such as iron oxide, ground flax fibers, wood cereals, pitch, refractory 
flours, and the like. 
When preparing an ordinary sand type foundry shape, the aggregate employed 
has a particle size large enough to provide sufficient porosity in the 
foundry shape to permit escape of volatiles from the shape during the 
casting operation. The term "ordinary sand type foundry shapes", as used 
herein, refers to foundry shapes which have sufficient porosity to permit 
escape of volatiles from it during the casting operation. 
Generally, at least about 80% and preferably about 90% by weight of 
aggregate employed for foundry shapes has an average particle size no 
smaller than about 50 and about 150 mesh (Tyler Screen Mesh). The 
aggregate for foundry shapes preferably has an average particle size 
between about 50 and about 150 mesh (Tyler Screen Mesh). The preferred 
aggregate employed for ordinary foundry shapes is silica wherein at least 
about 70 weight percent and preferably at least about 85 weight percent of 
the sand is silica. Other suitable aggregate materials include zircon, 
olivine, aluminosilicate sand, chromite sand, and the like. 
When preparing a shape for precision casting, the predominant portion and 
generally at least about 80% of the aggregate has an average particle size 
no larger than 150 mesh (Tyler Screen Mesh) and preferably between about 
325 mesh and 200 mesh (Tyler Screen Mesh). Preferably at least about 90% 
by weight of the aggregate for precision casting applications has a 
particle size no larger than 150 mesh and preferably between 325 mesh and 
200 mesh. The preferred aggregates employed for precision casting 
applications are fused quartz, zircon sands, magnesium silicate sands such 
as olivine, and aluminosilicate sands. 
When preparing a refractory such as a ceramic the predominant portion and 
at least 80 weight percent of the aggregate employed has an average 
particle size under 200 mesh and preferably no larger than 325 mesh. 
Preferably at least about 90% by weight of the aggregate for a refractory 
has an average particle size under 200 mesh and preferably no larger than 
325 mesh. The aggregate employed in the preparation of refractories must 
be capable of withstanding the curing temperatures such as above about 
1500.degree. F. which are needed to cause sintering for utilization. 
Examples of some suitable aggregate employed for preparing refractories 
include the ceramics such as refractory oxides, carbides, nitrides, and 
silicides such as aluminum oxide, lead oxide, chromic oxide, zirconium 
oxide, silica, silicon carbide, titanium nitride, boron nitride, 
molybdenum disilicide, and carbonaceous material such as graphite. 
Mixtures of the aggregate can also be used, when desired, including 
mixtures of metals and the ceramics. 
Examples of some abrasive grains for preparing abrasive articles include 
aluminum oxide, silicon carbide, boron carbide, corundum, garnet, emery, 
and mixtures thereof. 
The grit size is of the usual grades as graded by the United States Bureau 
of Standards. These abrasive materials and their uses for particular jobs 
are understood by persons skilled in the art and are not altered in the 
abrasive articles contemplated by the present invention. In addition, 
inorganic filler can be employed along with the abrasive grit in preparing 
abrasive articles. It is preferred that at least about 85% of the 
inorganic fillers has an average particle size no greater than 200 mesh. 
It is most preferred that at least about 95% of the inorganic filler has 
an average particle size no greater than 200 mesh. Some inorganic fillers 
include cryolite, fluorospar, silica, and the like. When an inorganic 
filler is employed along with the abrasive grit, it is generally present 
in amounts from about 1% to about 30% by weight based upon the combined 
weight of the abrasive grit and inorganic filler. 
Although the aggregate employed is preferably dry, it can contain small 
amounts of moisture, such as up to about 0.3% by weight or even higher 
based on the weight of the aggregate. 
In molding compositions, the aggregate constitutes the major constituent 
and the binder constitutes a relatively minor amount. In ordinary sand 
type foundry applications, the amount of binder is generally no greater 
than about 10% by weight and frequently within the range of about 0.5% to 
about 7% by weight based upon the weight of the aggregate. Most often, the 
binder content ranges from about 0.6% to about 5% by weight based upon the 
weight of the aggregate in ordinary sand type foundry shapes. 
In molds and cores for precision casting applications the amount of binder 
is generally no greater than about 40% by weight and frequently within the 
range of about 5% to about 20% by weight based upon the weight of the 
aggregate. 
In refractories, the amount of binder is generally no greater than about 
40% by weight and frequently within the range of about 5% to about 20% by 
weight based upon the weight of the aggregate. 
In abrasive articles, the amount of binder is generally no greater than 
about 25% by weight and frequently within the range of about 5% to about 
15% by weight based upon the weight of the abrasive material or grit. 
Although the aggregate employed is preferably dry, moisture of up to abou 1 
weight percent based on the weight of the sand can be tolerated. This is 
particularly true if the solvent employed is non-water-miscible or if an 
excess of the polyisocyanate necessary for curing is employed since such 
excess polyisocyanate will react with the water. 
The molding mix is molded into the desired shape, whereupon it can be 
cured. Curing can be affected by passing a tertiary amine through the 
molded mix as described in U.S. Pat. No. 3,409,579. 
A valuable additive to the binder compositions of the present invention in 
certain types of sand is a silane such as those having the general 
formula: 
##STR9## 
wherein R' is a hydrocarbon radical and preferably an alkyl radical of 1 
to 6 carbon atoms and R is an alkyl radical, an alkoxy-substituted alkyl 
radical, or an alkyl-amine-substituted alkyl radical in which the alkyl 
groups have from 1 to 6 carbon atoms. The aforesaid silane, when employed 
in concentrations of 0.1% to 2%, based on the phenolic binder and 
hardener, improves the humidity resistance of the system. 
Examples of some commercially available silanes are Dow Corning Z6040 and 
Union Carbide A-187 (gamma glycidoxy propyltrimethoxy silane); Union 
Carbide A-1100 (gamma aminopropyltriethoxy silane); Union Carbide A-1120 
(N-beta(aminoethyl)-gamma-amino-propyltrimethoxy silane); and Union 
Carbide A-1160 (Ureido-silane).

In order to further understand the present invention, the following 
non-limiting examples concerned with foundry are provided. All parts are 
by weight, unless the contrary is stated. In all examples the foundry 
samples are cured by the so-called "cold-box" process by contacting with 
dimethylethylamine. 
EXAMPLE 1 
100 parts by weight of Manley 1L-5W sand are admixed with about 0.825 parts 
of a phenolic resin composition, commercially available from Ashland 
Chemical under the trade designation Isocure.RTM. I 308 which contains 
about 48% by weight of a phenolic resole benzylic ether and about 52% by 
weight of a solvent mixture of aromatic hydrocarbon, kerosene, ester, and 
release agent. To the mixture are admixed about 0.008 parts of 
monophenyldichlorophosphate and about 0.675 parts of isocyanate 
composition commercially available from Ashland Chemical under the trade 
designation Isocure.RTM. II 606 containing, about 73% by weight of 
polymethylene polyphenyl isocyanate such as Mondur MR from Mobay, and 
about 27% by weight of a solvent mixture of kerosene and an aromatic 
solvent for about 2 minutes. The resulting foundry mix is forced into a 
core box by blowing. It is then contacted with a 12% by volume mix of 
dimethylethylamine in CO.sub.2 at 40 psi for 1 second, followed by purging 
with air that is at 60 psi for about 4 seconds, thereby forming AFS 
tensile strength samples (dog bones) using the standard procedure. The 
composition exhibits a bench life of at least 5 hours. 
The cured samples are tested for tensile strength. The average immediate 
tensile strength after the composition is aged for 5 hours before curing 
is about 84 psi and after 24 hours at relative humidity of 50% and 
25.degree. C. is about 155 psi. 
The average immediate tensile strength with no aging of the composition 
before curing is about 131 psi, after 1 hour at relative humidity of 50% 
and 25.degree. C. is about 191 psi, and after 24 hours at relative 
humidity of 50% and 25.degree. C. is about 237 psi. 
The average immediate tensile strength after the composition is aged for 3 
hours before curing is about 94 psi and after 24 hours under ambient 
conditions of 50% relative humidity and 25.degree. C. is about 171 psi. 
COMISON EXAMPLE 2 
Example 1 is repeated, except that no bench life extender is employed. 
The average immediate tensile strength after the composition is aged for 
about 5 hours before curing is about 49 psi and after 24 hours under 
ambient conditions of 50% relative humidity and 25.degree. C. is about 88 
psi. 
The average immediate tensile strength with no aging of the composition 
before curing is abou 127 psi, after 1 hour under ambient conditions of 
50% relative humidity and 25.degree. C. is about 181 psi, and after 24 
hours under ambient conditions of 50% relative humidity and 25.degree. C. 
is about 260 psi. 
The average immediate tensile strength after the composition is aged for 
about 3 hours before curing is about 68 psi and after 24 hours under 
ambient conditions of 50% relative humidity and 25.degree. C. is about 129 
psi. 
EXAMPLE 3 
The procedure of Example 1 is repeated, except that the amount of 
monophenyldichlorophosphate employed is about 0.004 parts by weight, the 
phenolic component contains about 58% by weight of the phenolic resole 
benzylic ether resin and 42% by weight of a solvent portion of aromatic 
hydrocarbon ester, release agent, and silane; and the isocyanate 
composition contains about 78% by weight of the polyisocyanate and about 
22% by weight of a solvent mixture of aromatic hydrocarbon and kerosene. 
The average immediate tensile strength after the composition is aged for 5 
hours before curing is about 96 psi and after 24 hours under ambient 
conditions of 50% relative humidity and 25.degree. C. is abou 175 psi. 
The average immediate tensile strength with no aging of the composition 
before curing is about 159 psi, after 1 hour under ambient conditions of 
50% relative humidity and 25.degree. C. is about 229 psi, and after 24 
hours under ambient conditions of 50% relative humidity and 25.degree. C. 
is about 283 psi. 
The average immediate tensile strength after the composition is aged for 3 
hours before curing is about 115 psi and after 24 hours under ambient 
conditions of 50% relative humidity and 25.degree. C. is about 193 psi. 
COMISON EXAMPLE 4 
Example 3 is repeated, except that no bench life extender is employed. 
The average immediate tensile strength after the composition is aged for 
about 5 hours before curing is about 47 psi and after 24 hours under 
ambient conditions of 50% relative humidity and 25.degree. C. is about 88 
psi. 
The average immediate tensile strength after the composition is aged for 3 
hours before curing is about 73 psi and after 24 hours under ambient 
conditions of 50% relative humidity and 25.degree. C. is about 131 psi. 
EXAMPLE 5 
The procedure of Example 3 is repeated, except that about 0.0216 parts by 
weight of diphenylmonochlorophosphate are employed as the bench life 
extender. 
The average immediate tensile strength after the composition is aged for 5 
hours before curing is about 68 psi and after 24 hours under ambient 
conditions of 50% relative humidity and 25.degree. C. is about 119 psi. 
The average immediate tensile strength after the composition with no aging 
of the composition before curing is about 169 psi and after 24 hours under 
ambient conditions of 50% relative humidity and 25.degree. C. is about 258 
psi. 
COMISON EXAMPLE 6 
Example 5 is repeated, except that no bench life extender is employed. 
The average immediate tensile strength after the composition is aged for 5 
hours before curing is about 40 psi and after 24 hours under ambient 
conditions of 50% relative humidity and 25.degree. C. is about 69 psi. 
The average immediate tensile strength after the composition with no aging 
of the composition before curing is about 163 psi and after 24 hours under 
ambient conditions of 50% relative humidity and 25.degree. C. is about 258 
psi. 
EXAMPLE 7 
Example 3 is repeated, except that the bench life extender employed is abou 
0.025 parts by weight of 
##STR10## 
added as a 45% solution in chlorobenzene. 
The average immediate tensile strength of the composition is aged for about 
5 hours before curing, is about 131 psi, and after 24 hours under ambient 
conditions of 50% relative humidity and 25.degree. C. is about 198 psi. 
The average immediate tensile strength after the composition is aged for 
about 3 hours before curing is about 151 psi and after 24 hours under 
ambient conditions of 50% relative humidity and 25.degree. C. is about 212 
psi. 
The average immediate tensile strength with no aging of the composition 
before curing is about 162 psi, after 1 hour under ambient conditions of 
50% relative humidity and 25.degree. C. is about 197 psi, and after 24 
hours under ambient conditions of 50% relative humidity and 25.degree. C. 
is about 252 psi. 
COMISON EXAMPLE 8 
Example 7 is repeated, except that no bench life extender is employed. 
The average immediate tensile strength after the composition is aged for 
about 5 hours is not determined since the composition is not flowable. 
The average immediate tensile strength after the composition is aged for 
about 3 hours before curing is about 74 psi and after 24 hours under 
ambient conditions of 50% humidity and 25.degree. C. is about 120 psi. 
The average immediate tensile strength with no aging of the composition 
before curing is about 166 psi, after 1 hour under ambient conditions of 
50% relative humidity and 25.degree. C. is about 229 psi, and after 24 
hours under ambient conditions of 50% relative humidity and 25.degree. C. 
is about 248 psi. 
A comparison of Examples 1, 3, 5, and 7 with Examples 2, 4, 6, and 8, 
respectively, clearly demonstrates the effectiveness of the 
organohalophosphates as bench life extenders. 
Examples 1, 3, 5, and 7 each contain a bench life extender employed 
according to the present invention, whereas Examples 2, 4, 6, and 8 do not 
include a bench life extender. The results demonstrates that although the 
tensile strength values for compositions with and without bench life 
extenders are not significantly different when the compositions are cured 
without aging, the tensile strengths for compositions with the 
organohalophosphate are significantly greater than those for compositions 
without the phosphate when the compositions are aged before curing as 
normally is experienced in commercial use.