Note: Descriptions are shown in the official language in which they were submitted.
_ckground of the Invention_ _ _ _ _
The present invention relates to binder compositions
and methods for curing such binder compositions. The binder
compositions of the present invention are especially useful as
molding compositions such as refractories, abrasive articles,
and molding shapes such as foundry cores and molds. The bin-
der compositions are capable of hardening at ambient temperatures.
Various binder systems now used including binders
for molding compositions employ inorganic substances as the
major components. However, prior art binders from inorganic
substances have suffered from one or more deficiencies. Typi-
cal of the deficiencies exhibited by prior art inorganic binders
including the silicates suggested for molding shapes such as
cores and molds have been poor collapsibility of the shape and
poor removal or "shake out" of the molding shape from the metal
casting.
Also, many of the suggested inorganic binders exhibit
inadequate bonding strength properties and/or undesirable
--1--
~067'~3
cure characteristics.
Moreover, various prior art inorganic binders such
as the silicates p~ovide molding shapes and particularly am-
bient temperature cured shapes which possess poor scratch re-
- sistance at strip; and accordingly, such shapes require at
least a few additional hours after strip tlme has been achieved
to develop adequate scratch resistance. In view of the poor
scratch resistance at strip, such shapes cannot be readily
handled at strip because of the danger of damage to the shape.
1~ Moreover, the sag resistance at strip of the shapes prepared
from various prior art binders is not good.
Another problem which may exist is the degradation
of physical properties such as tensile strength and hardness
of molded articles after storage for only a few hours.
It is therefore an object of the present invention
to provide inorganic binder systems which possess acceptable
- strength characteristics. It is another object of the present
invention to provide inorganic binder systems wherein the cure
characteristics can be manipulated within certain limits.
It is a further object of the present invention to
provide inorgan-ic binder systems for molding shapes which
possess relatively good collapsibility and shake out proper-
ties as compared to various other suggested inorganic binders,
It is another object of the present invention to
provide molding shapes employing inorganic binders which
possess good scratch and sag resistance at strip. Likewise,
-- 2
~067'~S3
it is an object of the present invention to provide molding
shapes from inorganie binder systems which can be readily and
easily handled at strip.
It is also an object of the present invention to
provide molded articles which demonstrate improved resistance
to deterioration of physical properties such as tensile
strength and hardness due to storage.
Summary of the Invention
The present invention is concerned with binder com-
positions which comprise:
(A) aluminum phosphate containing boron in
an amount up to about 40 mole ~ based
upon the moles of aluminum and contain-
ing a mole ratio of phosphorus to total
moles of aluminum and boron of about 2:1
to about 4:1;
(B) solid polyhydrie alcohol being soluble
in aqueous solutions of the aluminum
phosphate, and containing at least two
adjacent carbon atoms each having di-
rectly attached thereto one hydroxyl
group; and keto tautomers thereof;
(C) alkaline earth metal material containing
alkaline earth metal and an oxide; and
(D) water.
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~67Z53
The amount of aluminum phosphate is from about 50
to about 95~ by weight based upon the total weight of alumi-
num phosphate and alkaline earth material; and the amount of
alkaline earth material is from about 50 to about 5~ by
weight based upon the total weight of aluminum phosphate and
alkaline earth material. The amount of water is from about
15 to about 50% by weight based upon the total weight of alum-
inum phosphate and water. The amount of the polyhydric alco-
hol and/or keto tautomer thereof is from about 0.5 to about
25% by weight based upon the total weight of aluminum phos-
phate and polyhydric alcohol and/or keto tautomer.
The present invention is also concerned with compo-
sitions for the fabrication of molded articles such as refrac-
tories, abrasive articles such as grinding wheels, and shapes
used for molding which ;comprise:
(A) a major amount of aggregate; and
(B) an effective bonding amount up to
about 40% by weight of the aggregate
of the binder compositon defined above.
The present invention is also concerned with a pro-
cess for casting of relatively low melting point non-ferrous
type metal which comprises fabricating a shape from a composi-
tion which contains a major amount of aggregate and an effec-
tive bonding amount up to abDut 40% by weight of the aggregate
of the binder composition defined above; pouring the relatively
low melting point non-ferrous type metal while in the liquid
_ ~, _
~067~5~
state into the shape; allowing the non-ferrous type metal to
cool and solidify; then contacting the shape with water in an
amount and for a time sufficient to cause degradation of the
bonding characteristics of the binder system; and separating
the molded article.
Description of Preferred Embodiments
The aluminum phosphate constituent of the binder
system of the present invention is an aluminum phosphate which
contains boron in an amount up to about 40 mole % based upon
the moles of aluminum of the aluminum phosphate. Also, the
aluminum phosphate contains a mole ratio of phosphorous to
total moles of aluminum and boron of about 2:1 to about 4:1
and preferably from about 2.5:1 to about 3.5:1 and more pre-
ferably from about 2.8:1 to about 3.2:1,
Any of the several known methods may be employed to
produce an aluminum phosphate suitable for the present purposes.
In particular those methods wherein the aluminum oxide contain-
ing reactant is completely dissolved are preferred.
The aluminum phosphate also is preferably prepared
from either P2O5 or concentrated phosphoric acid of from about
70 to about 86% by weight H3PO4 concentration. The preferred
phosphoric acid solutions contain about 80 to about 86% by
weight of H3PO4. Of course, other sources of phosphorus such
as polyphosphoric acids, can be employed, if desired.
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~067'~S3
The amount of aluminum phosphate employed in the
binder system is from about 50 to about 95% by weight and
preferably from about 65 to about 90% by weight based upon the
total weight of aluminum phosphate and alkaline earth ma-
terial, and the amount of alkaline earth material is from
about 5 to about 50% and preferably from about 10 to about
35% by weight based upon the total weight of aluminum phos-
phate and alkaline earth material.
The preferred aluminum phosphates employed in the
present lnvention contain boron. Usually the boronated alum-
inum phosphates are prepared from boric acid and/or boric
oxide and/or metallic borates such as alkali metal borates
which include sodium borate ~Na2s4o7~loH2o). These preferred
aluminum phosphates are preferably, but not necessarily, pre-
pared by reacting together the phosphoric acid or P2O5; and
alumina such as alumina trihydrate (A12O3-3H2O); and boric
acid or boric oxide. It is preferred to use boric acid rather
than boric oxide since the acid is in a more usable form than
the oxide because of its greater solubility in the reaction
system as compared to the oxide.
Since the reaction is exothermic, it can generally
proceed by merely admixing the reactants and permitting the
exotherm to raise the temperature of the reaction mass until
the exotherm peaks, usually at about 200 to 230F. After the
exotherm peaks, it may be advantageous to apply external heat
for about 1/2 to 2 hours to maintain a maximum reaction
-- 6 --
~67'~3
temperature between about 220 and about 250 to insure comple-
tion of the reaction. Also, in some instances it may be de-
sirable to initiate the reaction by applying external heat just
until the exotherm begins.
The reaction is generally carried out at atmospheric
pressure. However, higher or lower pressures can be employed
if desired. In addition, the reaction is generally completed
within about 1 to about 4 hours and more usually from about 2
to about 3 hours~
The preferred aluminum phosphates contain from
about 3 to about 40 mole ~ of boron based upon the moles of
aluminum. The more preferred quantity of boron is between
about 5 and about 30 mole % while the most preferred quantity
is between about 10 and about 25 mole ~ based upon the moles
of aluminum.
Those aluminum phosphates which contain the boron
are preferred because of improved tensile strength achieved
in the final cured molded articles. The increased tensile
strength is even evident at the lower quantity of boron such
as at 3 mole %.
In addition, the modification with boron is ex-
tremely advantageous since it alters the reactivity of the
aluminum phosphate with the alkaline earth material in the
presence of aggregate. As the level of boron in the aluminum
phosphate increases, the rate of reaction with the alkaline
earth material in the presence of aggregate decreases. This
-- 7
1067;~S3
is particularly noticeable at boron concentrations of at
least about 10 mole % based upon the moles of aluminum.
Therefore, the boron modification aspect of the present in-
vention makes it possible to readily manipulate the cure
characteristics of the binder system so as to tailor the
binder within certain limits, to meet the requirements for
a particular application of the binder composition.
The alteration in the cure characteristics and
particularly with the free alkaline earth oxide; however,
has not been observed in the absence of aggregate such as
sand. This may be due to the exothermic nature of the re-
action between the aluminum phosphate and free alkaline
earth metal oxide whereby the presence of aggregate acts
as a heat sink reducing the reactivity to a level where the
effect of the boron modification becomes notlceable. On the
other hand, the reaction is so fast in the a~)sence of aggre-
gate that any effect which the boron may hav~ on cure is not
detectable and, even if detectable, it is O~ no practica
value.
In addition, the boron modification provides alum-
inum phosphate water solutions which exhibit greatly in-
creased shelf stability as compared to unmodified aluminum
phosphate materials, The enhanced shelf stability becomes
quite significant when employing quantities of boron of at
least about 5 mole % based upon the moles of aluminum,
Moreover, the use of the solid polyhydric alcohol
-- 8 --
1067ZS3
and/or its keto tautomer is most effective when boronated
aluminum phosphates are used. In particular, the effective-
ness of the polyhydric alcohol or its keto tautomer on im-
proving the stability of physical properties of cured molded
articles is increased when using boronated aluminum phos-
phates, and especially when using the larger quantities of
boron such as from about 10 to about 30 mole % based upon
the moles of aluminum, Moreover, the effect of the poly-
hydric alcohols has been quite noticeable when binder-
aggregate compositions have been baked such as at about300-350F for up to about 30 minutes.
The polyhydric alcohols employed according to the
present invention are solid at ambient temperature and are
soluble in aqueous solutions of the aluminum phosphate. In
addition, the polyhydric alcohols contain at least two adja-
cent carbon atoms each having directly attached thereto a
hydroxy group, or are the keto tautomers thereof. The poly-
hydric alcohols usually contain from about 2 to about 20 hydroxyl
groups and preferably from about 2 to about 10 hydroxyl groups
in the molecule. In addition, these substances employed ac-
cording to the present invention generally contain 2 to about
20 carbon atoms and preferably from about 2 to about 10 carbon
atoms. In addition, the polyhydric alcohols can contain other
groups or atoms which do not adversely a~fëct the function of
the material in the compositions of the present invention to
an undesirable extent. For instance, many of the polyhydric
g _
~067253
alcohols employed in the present invention contain ether and/
or carboxyl moieties. Also, the polyhydric alcohols are us-
ually non-polymeric. Examples of some polyhydric alcohols
include sorbitol, sucrose, invert sugar, D-glucose, B-glucose,
dihydroxy succinic acid (tartaric acid), gluconic acid, 1,2,6-
hexane triol, The preferred polyhydric alcohols are sorbitol
and dihydroxy succinic acid.
The amount of polyhydric alcchol employed in the
present invention is usually from about 0.5 to about 25% by
weight and preferably from about 2 to about 15% by weight
based upon the total weight of the aluminum phosphate and
alcohol,
The alkaline earth metal material employed in the
present invention is any material containing an alkaline
earth metal and containing an oxide which is capable of re-
acting with the boronated aluminum phosphate. When the
alkaline earth metal material is a free alkaline earth metal
oxide or a free alkaline earth metal hydroxide, it preferably
has a surface area no greater than about 8,5 m2/gram as
measured by the BET procedure. More preferablY it has a
surface area no greater than about 3 m2~gram. Those free
oxides and free hydroxides having surface areas no greater
than about 8.5 m2/gram are preferred when the binders are
employed in molding compositions such as for preparing re-
fractories, abrasive articles and particularly for making
shapes such as foundry cores and molds,
-- 10 --
- 10f~7'~53
It has been observed that compositions of the pre-
sent invention which employ the preferred oxides and hydroxides
have sufficient work times to be adequately mixed in the more
conventional types of commercially available batch type mixers
before introduction into the mold or pattern for shaping. Al-
though free oxides and free hydroxides having surface areas
greater than about 8.5 m2/gram generally are too reactive for
use with the more conventional types of commercially available
batch type mixers, they are suitable when much faster mixing
operations are employed such as those continuous mixing oper-
ations which may require only about 20 seconds for adequate
mixing or when the binders are to be employed for purposes
wherein substantially instantaneous cure is desirable and/or
can be tolerated.
Those materials which contain an oxide or hydroxide
and an alkaline earth metal, in chemical or physical combina-
tion with other constituents are less reactive than the free
oxides and hydroxides. Accordingly, such materials can have
surface areas greater than about 8.5 m /gram and be suitable
for use even when~employing mixing operations which require
about 2 to 4 minutes or more.
These other constituents may be present such as
being chemically combined with the oxide and alkaline earth
metal and/or being physically combined such as by sorption
or in the form of an exterior coating. However, the mere
mixing of a material with a free oxide or hydroxide without
lO~ S3
achieving the above type of uniting of the material would
not materially reduce the reactivity. Therefore, such mere
mixing is not included within the meaning of chemical or
physical combinations as used herein.
However, it is preferred that all of the alkaline
earth metal materials employed in the present invention have
a surface area of no greater than about 8.5 m /gram and more
preferably have a surface area of no greater than about 3
m /gram. Usually the surface areas are at least about 0.01
m /gram. All references to surface area unless the contrary
is stated, refer to measurements by the BET procedure as set
forth in tentative ASTM-D-3037-71T method C-Nitrogen Absorp-
tion Surface Area by Continuous Flow Chromatography, Part 28,
page 1106, 1972 Edition, employing 0.1 to 0.5 grams of the
alkaline earth material.
Included among the suitable materials are calcium
oxides-, magnesium oxides, calcium silicates, calcium alumi-
nates, calcium aluminum silicates, magnesium silicates, and
magnesium aluminates. Also included among the suitable ma-
terials of the present invention are the zirconates, borates,
and titanates of the alkaline earth metals.
It is preferred to employ either a free alkaline
earth metal oxide or a mixture of a free alkaline earth metal
oxide and a material which contains the alkaline earth metal
and oxide in combination with another constituent such as
calcium aluminates. In addition, the preferred alkaline earth
12
\
~(~67253
metal oxides are the magnesium oxides.
Those materials which include components in combi-
nation with the oxide or hydroxide, and the alkaline earth
metal, in some instances can be considered as being a latent
source of the alkaline earth metal oxide for introducing the
alkaline earth metal oxide into the binder system.
Some suitable magnesium oxide materials are avail-
able under the trade designations of Magmaster l-A*from
Michigan Chem1cal, Calcined Magnesium Oxide, -325 mesh, Cat.
No. M-1016 from Cerac/Pure, Inc.; H-W Periklase Grain 94C
Grade (Super Ball Mill Fines); H-W Periklase Grain 94C Grade
(Regular Ball Mill Fines); and H-W Periklase Grain 98,
~Super Ball Mill Fines) from Harbison-Walker Refractories.
Magmaster l-A has a surface area of about 2.3 m2/gram and
Cat. No. M-1016 has a surface area of about 1.4 m2/gram.
A particularly preferred calcium silicate is
Wollastonite which is a particularly pure mineral in which
the ratio of calcium oxide to silica is substantially equal
molar.
Generally commercially available calcium aluminate
compositions contain from about 15 to about 40% by weight of
calcium oxide and from about 35 to about 80% ~y weight of
alumina, with the sum of the calcium oxide and alumina being
at least 70% by weight. Of course, it may be desirable to
obtain calcium aluminate compositions which contain greater
percentages of the calcium oxide. In fact, calcium aluminates
* Trade Marks
~06~'~3
containing up to about 45.5% by weight of calcium oxide have
been obtained. Some suitable calcium aluminate materials
can be obtained commercially under the trade designations
Secar 250 and Fondu from Lone Star Lafarge Company, Lumnite
and Refcon*from Universal Atlas Cement and Alcoa Calcium
Aluminate Cement CA-25 from Aluminum Company of America.
Fondu has a minimum surface area as measured by ASTM C115 of
about 0.15 m2/gram and 0.265 m2/gram as measured by ASTM C205.
Lumnite has a Wagner specific surface of 0.17 m2/gram and
Refcon has a Wagner specific surface of 0.19 m2/gram.
Mixtures of a free alkaline earth metal oxide and
a material containing components in combination wlth the
free oxide or hydroxide and alkaline earth metal preferably
contain from about 1 part by weight to about 10 parts and
more preferably from about 2 to about 8 parts by weight of
the free alkaline earth metal oxide per part by weight of
the material containing constituents in combination with
the free metal oxide or hydroxide and alkaline earth metal.
Preferably such mixtures are of magnesium oxides and calcium
aluminates. The free alkaline earth metal oxide such as mag-
nesium oxides in such mixtures are primarily responsible for
achieving fast cure xates while the other component such as
the calcium aluminates are mainly responsible for improving
the strength characteristics of the f1nal shaped article.
Since the free metal oxide is a much more reactive material
than those materials which are latent sources of the free
* Trade Marks
14
-- `~
1067~S3
metal oxide, those other materials will only have a minimal
effect upon the cure rate when in admixture with the alkaline
earth metal oxide.
Sometimes it may be desirable to employ the alka-
line earth metal material in the form of a slurry or suspen-
sion in a diluent primarily to facilitate material handling.
Examples of some suitable liquid diluents include alcohols
such as ethylene glycol, furfuryl alcohol, esters such as
cellosolve acetate, and hydrocarbons such as kerosene, min-
eral spirits (odorless), mineral spirits regular, and 140
Solvent available from Ashland Oil, Inc., and Shellflex 131*
from Shell Oil, and aromatic hydrocarbons commercially avail-
* *
able under the trade designations H-Sol 4-2 and Hi-Sol 10
from Ashland Oil, Inc. Of course, mixtures of different
diluents can be employed, if desired. In addition, it may
be desirable to add a suspending agent to slurries of the
alkaline earth material such as Bentone,* Cabosil,* and
Carbopol* in amounts up to about 10% and generally up to less
than 5% to assist in stabilizing the slurry or suspension in
the diluent.
Generally the alkaline ear~h metal material and
diluent are mixed in a weight ratio of about 1:3 to about
3:1 and preferably from about 1:2 to about 2:1. It has been
observed that the non-polar hydrocarbons provide the best
strength characteristics as compared to the other diluents
which have been tested, when a diluent is employed. In
* Trade Marks
~67253
addition, the alcohols such as ethylene glycol and furfuryl
alcohol are advantageous as liquid diluents since they in-
crease the work time of the foundry mix without a corres-
ponding percentage increase in the strip time. However,- the
strength properties of the final foundry shape are somewhat
reduced when employing alcohols such as ethylene glycol and
furfuryl alcohol.
The other necessary component of the binder system
employed in the present invention is water. All or a por-
tion of the water can be supplied to the system as the car-
rier for the boronated aluminum phosphate material, Also,
the water can be introduced as a separate ingredient. Of
course, the desired quantity of water can be incorporated in
part as the water in the boronated aluminum phosphate and in
part from another source, The amount of water employed is
from about lS to about 50% by weight and preferably from
about 20 to about 40~ by weight based upon the total weight
of the boronated aluminum phosphate and water.
The binder composition of the present invention
makes possible the obtaining of molded articles including
abrasive articles such as grinding wheels, shapes for mold-
ing and refractories such as ceramics having improved re-
sistance to deterioration of physical properties such as
tensile strength and hardness due to storage. The loss in
such physical properties after storage for several hours
(i.e., 24 hours or more) is less when employing the binder
- 16 -
1()67'~53
composition of this invention as compared to employing binder
composition which differ only in not including a solid poly-
hydric alcohol of the type employed in the present invention.
The improvement in the stability of physical properties of
the cured articles such as molds and cores is most pronounced
when the aluminum phosphate is a boronated aluminum phosphate,
The effect of the solid polyhydric alcohol is much greater
when a boronated aluminum phosphate is used instead of a non-
boronated aluminum phosphate.
In addition, it has been observed that the presence
of the solid polyhydric alcohol in the binder composition of
the present invention improves the flowability of mixtures of
the binder composition and aggregate for molding operations.
It has further been observed that the surface fin-
ishes of articles cast in molds or cores prepared from compo-
sitions of the present invention are improved as compared to
compositions which do not contain the solid polyhydric alcohol
constituent. It has further been observed that the solid
polyhydric alcohols in the amounts employed increase both
the work and strip times of molding compositions.
Also, other materials which do not adversely affect
the interrelationship between the boronated aluminum phosphate,
solid polyhydric alcohol, alkaline earth metal component, and
water can be employed, when desired.
When the binder composition of the present inven-
tion is used in molding compositions such as for preparing
- 17 -
1~67Z53
abrasive artisles including grinding wheels, refractories in-
cluding ceramics and structures for molding such as ordinary
sand type foundry shapes and precision casting shapes, aggre-
gate is employed along with the binder of the present invention,
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 opera-
tion. 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 at
least about 90% by weight of aggregate employed for foundry
shapes has an average particle size no smaller than about 150
mesh (Tyler Screen Mesh). The aggregate for foundry shapes
preferably has an average particle si~e 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 ~ and preferably at least about 85
weight ~ of the sand is silica. Other suitable aggregate ma-
terials include zircon, olivine, alumino-silicate sand, chro-
mite sand, and the like.
When preparing a shape for precision casting, the
predominate 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
- 18 -
~0672~i3
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.
Shapes for pxecision casting differ from ordinary
- sand type foundry shapes in that the aggregate in shapes for
precision casting can be more densely packed than the aggre-
gate in shapes for ordinary sand type foundry shapes. There-
fore, shapes for precision casting must be heated before
being utilized to drive off volatilizable material, present
in the molding composition. If the volatiles are not removed
from a precision casting shape before use, vapor created dur-
ing casting will diffuse into the molten metal since the shape
has a relatively low porosity~ The vapor diffusion would de-
crease the smoothness of the surface of the precision cast
- article.
When preparing a refractory such as a ceramic, the
predominant portion and at least about 80 weight % 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
-- 19 --
~067253
preparation of refractories must be capable of withstanding
the curing temperatures such as above about 1500F which
are needed to cause sintering for utilization. Examples of
some suitable aggregates 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
aggregates 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. There abrasive materials and
their uses for particular jobs are understood by persons
skilled in the art and are not altered in the abrasive ar-
ticles contemplated by the present invention. In addit~on,
inorganic fillers can be employed along with the abrasive
grit in preparing abrasive articles. It is preferred that
at least about 85% of the inorganic fillers have average
particle size no greater than 200 mesh. It is most preferred
that at least about 95% of the inorganic filler has an aver-
age particle size no greater than 200 mesh. Some inorganic
fillers include cryolite, fluorospar, silica and the like.
- 20 -
~067Z53
When an inorganic filler is employed along with the abrasive
grit, it is generally present in an amount from about l 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. Such moisture present on the aggregate can
be compensated for, by altering the quantity of water added
to the composition along with the other components such as
the aluminum phosphate, solid polyhydric alcohol and alka-
line earth metal material.
In molding composition, 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 l to about
5% by weight based upon the weight of the aggregate in ordi-
nary sand type foundry shapes.
In molds and cores for precision casting applica-
tions, 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 aggre-
gate.
- 21 -
~)67Z53
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 gen-
erally no greater than about 25% by weight and frequen-tly
within the range of about 5% to about 15% by weight based
upon the weight of the abrasive material or grit.
At the present time, it is contemplated that the
binder compositions of the present invention are to be made
available as a two-package system comprising the aluminum
phosphate, solid polyhydric alcohol, and water components
in one package and the alkaline earth metal component in the
other package.
When the binder compositions are to be employed
along with an aggregate, the contents of the package con-
taining the alkaline earth metal component are usually ad-
mixed with the aggregate, and then the contents of the alum-
inum phosphate containing package are admixed with the aggre-
gate and alkaline earth metal component composition. After
a uniform distribution of the binder system on the particles
of aggregate has been obtained, the resulting mix is molded
into the desired shape. Methods of distributing the binder
on the aggregate particles are well known to those skilled
in the art. The mix can, optionally, contain other ingred-
ients such as iron oxide, ground flax fibers, wood cereals,
- 22 -
~067Z53
clay, pitch, refractory flours, and the like,
The binder systems of the prevent invention are
capable of ambient temperature cure which is used herein to
include curing by chemical reaction without the need of ex-
ternal heating means. However, within the general descrip-
tion of ambient temperature cure, there are a number of
different ambient temperature curing mechanisms which can
be employed. For example, ambient temperature cure encom-
passes both "air cure" and "no bake". Normally, ambient
temperature cure is effected at temperatures of from about
50 F to about 120 F.
Moreover, the molding shapes of the present inven-
tion have good scratch resistance and sag resistance immed-
iately at strip Accordingly, the molding shapes of the
present invention can be easily and readily handled and em-
ployed immediately after strip.
In addition, the binder systems of the present in-
vention make possible the achievement of molding shapes which
possess improved collapsibility and shake out of the shape
when used for the casting of the relatively high melting point
ferrous-type metals such as iron and steel which are poured
at about 2500 F, as compared to other inorganic binder sys-
tems such as the silicates.
Furthermore, the binder systems of the present
invention make possible the preparation of molding shapes
which can be employed for the casting of the relatively low
- 23 -
~0672S3
melting point non-ferrous type metals such as aluminum,
copper, and copper alloys including brass. The tempera-
tures at which such metals are poured in certain instances
may not be high enough to adequately degrade the bonding
characteristics of the binder systems of the present inven-
tion to the extent necessary to provide the degree of
collapsibility and shake out by simple mechanical forces
which are usually desired in commercial type of applications.
However, the binder systems of the present inven-
tion make it possible to provide molding shapes which can becollapsed and shaken out from castings of the relatively low
melting point non-ferrous type metals and particularly alum-
inum, by water leaching. The shapes can be exposed to water
such as by soaking or by a water spray. Moreover, it has
been observed that the surface appearance of aluminum cast
articles when employing shapes according to the present in-
vention is quite good.
The binder systems of the present invention fur-
ther make possible the achievement of molding shapes which
can be successfully used for casting molten refractory par-
ticles in fused casting processes.
It has been also observed that with the binder
systems of the present invention, it is possible to readily
reclaim and reuse the aggregate employed in such applica-
tions as foundry cores and molds after destruction of the
shape. In fact, sand aggregate has been successfully
10~7~53
reclaimed and reused for at least seven cycles in foundry
cores and molds.
When the compositions of the present invention
are used to prepare ordinary sand type foundry shapes, the
following steps are employed:
(1) forming a foundry mix containing an
aggregate (e.g., sand) and the con-
tents of the binder system;
(~2) introducing the foundry mix into a
mold or pattern to thereby obtain a
green foundry shape;
(3) allowing the green foundry shape to
remain in the mold or pattern for a
time at least sufficient for the shape
to obtain a minimum stripping strength
(i.e., become self-supporting); and
(4) thereafter removing the shape from the
mold or pattern and allowing it to cure
at room temperature, thereby obtaining
a hard, solid, cured foundry shape.
In order to further understand the present invention
the following non-limiting examples concerned with foundry
shapes are provided. All parts are by weight unless the con-
trary is stated. In all the examples, the samples are cured
by no-bake procedure at room temperature unless the contrary
is stated. The core hardness in the examples was measured on
- 25 -
1067'~:53
a No. 674 Core Hardness Tester commercially available from
Harry W. Dietert Co., Detroit, Michigan.
Example 1
To a round bottom, 3 liter, 3-necked reaction flask
fitted with a heating mantle, mechanical stirrer, reflux con-
denser and thermometer are added 1650 parts of 85% phosphoric
acid. Under mild agitation, 50 parts of granular boric acid
are charged to yield a boric acid-phosphoric acid dispersion.
The boric acid is added as a smooth steady "stream", as op-
posed to dumping in bulk, to avoid clumping. To the agitated
dispersion are added 310 parts of hydrated alumina (Alcoa,
C-33 grade) as a smooth steady stream to give a milky-white
slurry.
The reaction mass is heated to a temperature of
about 110-120 F in about 1/2 hour at which time external
heat is removed. The reaction is continued for about another
20 to 30 minutes with the temperature rising to a maximum of
about 220-230 F due to the reaction exotherm. Then external
heat is applied and reaction temperature rises to a maximum
of about 245-250 F at which point refluxing occurs. The
reaction mass is held at about 245-250 F for about 1.5-2
hours to ensure complete reaction. The reaction mass is
cooled to about 200 F in about ~5 minutes at which time
about 260 parts of water are slowly added with agitation.
The temperature of the reaction mass then drops to about
- 26 -
1~)67Z5~3
150-160 F. About 2270 parts of product are then collected
in glass-line polypropylene containers. The product is a
boronated aluminum phosphate product having a solids content
of 66.6%, a viscosity of 700-750 centipoises, mole ratio of
phosphorus to total moles of aluminum and boron of 3:1, and
about 20 mole % boron based upon the moles of aluminum; a pH
of 1,5-2.0 and Gardner color of 2.
5000 parts of Port Crescent sand and about 35 parts
of a mixture of magnesium oxide having a surace area of
about 2.3 m2/gram (Magmaster l-A) and Calcium Aluminate
(Recon) in a ratio of 5 parts of magnesium oxide to 1 part
of calcium aluminate are admixed for about 2 minutes. To
this mixture are added a mixture of about 157.5 parts of the
boronated alu~inum phosphate product prepared above and about 7.5
parts of sorbitol. The mixture is then agitated for 2 minutes.
- The resulting foundry mix is formed by hand ramming
into standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars and
core hardness are set forth in ~able I below. The composition
has a work time of 12 minutes and a strip time of 43 minutes.
Example 2
Example 1 is repeated except that about 13.5 parts
of sorbitol and about 152.5 parts of the boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
~()67Z53
procedure. The tensile strength of the test bars and core
hardness are set forth in Table I below. The composition
has a work time of 11 minutes and a strip time of 36 minutes.
Example 3
Example 1 is repeated except 165 parts of the bor-
onated aluminum phosphate without any sorbitol are employed.
The resulting foundry mix is formed into standard AFS ten-
sile strength sample~ using the standard procedure. The
tensile strength of the test bars and core hardness are set
forth in Table I below. The composition has a work time of
16 minutes and a strip time of 48 minutes.
28
1067ZS3
Table I
Example 1 Exam~le 2
% of sorbitol
based upon sor-
bitol and alum- 4.5 8.2
inum phosphate
solution
Work time
(minutes) 12 11
Strip time
~minutes) 43 36
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 100 90 150 88
4 150 88 185 86
6 185 88 210 94
24 215 85 230 86
48 220 78 245 88
72 190 75 255 81
2g
1067ZS3
Table I
(Continued)
Example 3
% of sorbitol
based upon sor-
bitol and alum- 0
inum phosphate
solution
Work time
(minutes) 16
Strip time
(minutes) 48
Time (hours) Tensile Core
streng~h hardness
psi
2 115 86
4 175 84
6 205 85
24 160 81
48 135 74
72 105 68
. 30
1067Z53
Example 4
Example 1 is repeated except that a non-boronated
aluminum phosphate having a solids content of 66.6% and a mole
ratio of phosphorous to moles of aluminum of 3:1 is employed.
The resulting foundry mix is formed into standard AFS tensile
strength samples using the standard procedure. The tensile
strength of the test bars and core hardness are set forth below
in Table II. The composition has a work time of 15 minutes
and a strip time of 42 minutes.
Example 5
Example 4 is repeated except that about 13.5 parts
of sorbitol and 152.5 parts of the aluminum phosphate are em-
ployed. The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure. The
tensile strengths of the test bars and core hardness are set
forth below in Table II. The composition has a work time of 8
minutes and a strip time of 32 minutes.
Example 6
Example 4 is repeated except that 165 parts of the
aluminum phosphate without any sorbitol are employed. The
resulting foundry mix is formed into standard AFS tensile
strength samples using the standard procedure. The tensile
strength of the test bars and core hardness are set forth below
in Tab~e II. The composition has a work time of 11 minutes
and a strip time of 33 minutes.
- - 31 -
'~ 067ZS3
Table II
Example 4 Example 5
% of sorbitol
based upon sor-
bitol and alum- 4.5 8.2
inum phosphate
solution
Work time
(minutes) 15 8
Strip time
(minutes) 42 32
Time (hours) Tensile Core Tensile Core
strength hardness Strength hardness
psi psi
2 105 85 115 82
4 135 75 160 84
6 170 75 160 86
24 155 75 125 81
48 145 71 145 78
72 115 63 115 81
~1~67Z53
Table II
(Continued)
Example 6
% of sorbitol
based upon sor-
bitol and alum- 0
inum phosphate
solution
Work time
(minutes) 11
Strip time
(minutes) 33
Time (hours) Tensile Core
strength har~ness
psi
2 105 74
4 145 80
6 150 70
24 lO0 69
48 90 78
72 85 73
1067253
Example 7
5000 parts of Port Crescent Lake sand and about 25
parts of a mixture of magnesium oxide having a surface area
of about 2.3 m /gram (~agmaster l-A) and calcium aluminate
(Refcon) in a ratio of 5 parts of magnesium oxide to 1 part
of calcium aluminate are admixed for about 2 minutes. To
this mixture are added a mixture of about 156.65 parts of an
aluminum phosphate prepared along the lines of the procedure
in Example 1 and having a solids content of 66.6%, viscosity
of 700-750 centipoises, mole ratio of phosphorous to total
. moles of aluminum and boron of 3:1, about 20 mole % boron
based upon the moles of aluminum, pH of 1.5-2~0 and Gardner
color of 2, and about 8.35 parts of 1,2,6-hexanetriol. The
mixture is then agitated for 2 min~tes.
The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness are
set forth below in Table III. The composition has a work
time of about 30 minutes and a strip time of about 82 minutes.
ExamPle 8
- Example 7 is repeated except that about 13.5 parts
of 1,2,6-hexanetriol and about 151.5 parts of the boronated
aluminum phosphate are employed. The resulting foundry mix
is formed into standard AFS tensile strength samples using
the standard procedure. The tensile strength of the test
- 34 -
la67zs3
bars and core hardness are set forth below in Table III.
The composition has a work time of about 33 minutes and a
strip time of about 75 minutes.
Example 9
Example 7 is repeated except that 165 parts of
the boronated aluminum phosphate without any of the 1,2,6-
hexanetriol are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars and core
hardness are set forth below in Table III. The composition
has a work time of about 14 minutes and a strip time of about
40 minutes.
~067Z53
Table III
Example 7 Example 8
% 1,2,6-hexanetriol
based upon total of
1,2,6-hexanetriol5.06 8.20
and aluminum phos-
phate solution
Work time
(minutes) 30 33
Strip time
(minutes) 82 75
Time (hours)Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 6~ 90 60 75
24 125 82 115 85
48 150 86 125 80
72 155 93 135 92
36
~067Z53
Table III
(Continued)
Example 9
% 1,2,6-hexanetriol
based upon total of
1,2,6-hexanetriol 0
and aluminum pho~-
phate solution
Work time
(minutes) 14
Strip time
(minutes) 40
Time (hours) Tensile Core
strength hardness
psi
2 130 95
4 190 90
6 215 85
24 85 72
48 110 67
72 90 74
iO67Z53
Example 10
5000 parts of Port Crescent Lake sand and about 25
parts of a mixture of magnesium oxide having a surface area
of about 2.3 m2 .gram (Magmaster l-A) and calcium aluminate
(Refcon) in a ratio of 5 parts of magnesium oxide to 1 part of
calcium aluminate are admixed for about 2 minutes. To this
mixture are added a mixture of about 158 parts of an aluminum
phosphate prepared along the lines of the procedure in Example
1 and having a solids content of 66.6%, viscosity of 700-750
centipoises, mole ratio of phosphorus to total moles of aluminum
and boron of 3:1, about 20 mole % boron based upon the moles
of aluminum, pH of 1.5 - 2.0 and Gardner color of 2, and
about 7 parts of gluconic acid. The mixture is then agitated
for 2 minutes.
The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness are
set forth below in Table IV. The composition has a work time
of about 19 minutes and a strip time of about 62 minutes.
Example 11
Example ]0 is repeated except that about 10.3 parts
of gluconic acid and about 154.7 parts of the boronated
aluminum phosphate are employed. The resulting foundry mix
is formed into standard AFS tensile strength samples using
the standard procedure. The tensile strength of the test
- 38 -
~067Z53
bars and core hardness are set forth below in Table IV.
The composition has a work time of about 23 minutes and
a strip time of about 58 minutes.
Example 12
Example lO is repeated except that about 16.5
parts of gluconic acid and about 148,5 parts of the boro;-
nated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensile strength
samples using the standard procedure. The tensile strength
of the test bars and core hardness are set forth below in
Table IV. The composition has a work time of about 18
minutes and a strip time of about 55 minutes.
Example 13
Example 10 is repeated except that 165 parts of the
boronated aluminum phosphate without any gluconic acid are
employed. The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness are
-~-
set forth in Table IV below. The composition has a work time
of about 14 minutes and a strip time of about 40 minutes.
- 39 -
~067ZS3
Table IV
Example 10 Example 11
% gluconic acid
based upon total
of gluconic acid 4~25 6.25
and aluminum phos-
phate solution
Work time
(minutes) 19 23
Strip time
(minutes) 62 58
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
ps i ps i
2 95 88 100 90
4 160 90
6 220 91
24 200 90 240 89
48 245 88 215 88
72 150 92 235 91
1067'~53
Table IV
tContinued)
Example 12 Exam~le 13
% gluconic acid
based upon total
of gluconic acid 10 0
and aluminum phos-
phate solution
Work time
(minutes) 18 14
Strip time
(minutes) 55 40
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 105 91 130 95
4 160 91 190 90
6 205 91 215 85
24 220 92 85 72
48 250 90 110 67
72 225 86 90 74
41
la67zs3
Example 14
5000 parts of Port Crescent Lake sand and about
25 parts of a mixture of magnesium oxide having a surface
area of about 2.3 m /gm tMagmaster l-A) and calcium alumi-
nate (Refcon) in a ratio of 5 parts of magnesium oxide to
1 part of calcium aluminate are admixed for about 2 minutes.
To this mixture are added a mixture of about 156.65 parts
of an aluminum phosphate prepared along the lines of the
procedure in Example 1 and having a solids content of 66.6%,
viscosity of 700-750 centipoises, mole ratio of phosphorus
to total moles of aluminum and boron of 3:1, about 20 mole %
boron based upon the moles of aluminum, pH of 1.5-2.0 and
Gardner color of 2, and about 8.35 parts of d-tartaric acid.
The mixture is then agitated for 2 minutes.
The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness are
set forth below in Table V. The composition has a work time
of about 16 minutes and a strip time of about 52 minutes.
Example 15
Example 14 is repeated except that about 13.5 parts
of d-tartaric acid and about 151.5 parts of the boronated
aluminum phosphate are employed. The resulting foundry mix
is formed into standard AFS tensile strength samples using
the standard procedure. The tensile strength of the test bars
- - 42 -
1067Z53~
and core hardness are set forth below in Table V. The compo-
sition has a work time of about 15 minutes and a strip time
of about 51 minutes.
Example 16
Example 14 is repeated except that about 2 parts
of d-tartaric acid and about 163 parts of the boronated
aluminum phosphate are employed. The resulting foundry mix
is formed into standard AFS tensile strength samples using
the standard procedure~ The tensile strength of the test
bars and core hardness are set forth below in Table V. The
composition has a work time of about 16 minutes and a strip
time of about 58 minutes.
Example 17
Example 14 is repeated except that about 4 parts
of d-tartaric acid and about 161 parts of the boronated
aluminum phosphate are employed. The resulting foundry mix
is formed into standard AFS tensile strength samples using
the standard procedure. The tensile strength of the test
bars and core hardness are set forth below in Table V.
The composition has a work time of about 15 minutes and a
strip time of about 42 minutes.
- 43 -
1067Zt~3
Example 18
Example 14 is repeated except that 165 parts of
the boronated aluminum phosphate without any d-tartaric
acid are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the
standard procedure. The tensile strength of the test bars
and core hardness are set forth below in Table V. The com-
position has a work time of about 14 minutes and a strip
time of about 40 minutes.
44
1067ZS3
Table V
Example 14 Example 15
% d-tartaric acid
based upon total of
d-tartaric acid and 5~06 8.2
aluminum phosphate
solution
Work time
tminutes) 16 15
Strip time
(minutes) 52 51
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 130 94 145 89
4 165 92
6 195 91
24 270 91 260 86
48 ~ 220 88 225 85
72 195 86 215 88
1067Z53
Table V
(Continued)
Example 16 Example 17
% d-tartaric acid
based upon total of
d-tartaric acid and 1.2 2.43
aluminum phosphate
solution
Work time
(minutes) 16 15
Strip time
(minutes) 58 42
Time ~hours) Tensile Core Tensile Core
strength hardness strength hardness
p.~ i ps i
2 150 91 105 90
4 200 85 180 88
6 200 85 205 84
24 260 86
48
72 185 85 240 86
96 195 88 215 85
120 210 88
46
1067ZS3
Table V
(Continued)
Example 18
% d-tartaric acid
based upon total of
d-tartaric acid and 0
aluminum phosphate
solution
Work time
(minutes) 14
Strip time
(minutes) 40
Time (hours) Tensile Core
strength hardness
p3i
2 130 95
4 190 90
6 215 85
24 B5 72
48 110 67
72 90 74
47
1067Z53
Example 19
5000 parts of Port Crescent Lake sand and about
25 parts of a mixture of magnesium oxide having a surface
area of about 2.3 m~/gm (Magmaster l-A) and calcium alum-
inate (Refcon) in a ratio of 5 parts of magnesium oxide to
1 part of calcium aluminate are admixed for about 2 minutes.
To this mixture are added a mixture of about 160 parts of
an aluminum phosphate prepared along the lines of the pro-
cedure in Example 1 and having a solids content of 66. 6%,
viscosity of 700-750 centipoises, mole ratio of phosphorus
to total moles of aluminum and boron of 3:1, about 20 mole
% boron based upon the moles of aluminum, pH of 1.5-2.0 and
Gardner color of 2, and about 5 parts of invert sugar. The
mixture is then agitated for 2 minutes.
The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness
are set forth below in Table VI. The composition has a
work time of about 12 minutes and a strip time of about 42
minutes.
Example 20
Example 19 is repeated except that about 10 parts
of invert sugar and about 155 parts of the boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
48
~O~à7253
procedure. The tensile strength of the test bars and core
hardness are set forth below in Table VI. The composition
has a work time of ab~out 10 minutes and a strip time of
about 41 minutes.
Example 21
Example 19 is repeated except that about 14 parts
of invert sugar and about 151 parts of the boronated alumi-
num phosphate are employed. The resulting foundry mix is
formed into standard AFS tensile strength samples using the
standard procedure. The tensile strength of the test bars
and core hardness are set forth below in Tab~e VI. The com-
position has a work time of about 10 minutes and a strip
time of about 44 minutes.
Example 22
Example 19 is repeated except that about 18 parts
of inve~rt sugar and about 147 parts of the boronated alumi-
num phosphate are employed. The resulting foundry mix is
formed into standard AFS tensile strength samples using the
standard procedure. The tensile strength of the test bars
and core hardness are set forth below in Table VI. The
composition has a work time of about 11 minutes and a strip
time of about 45 minutes.
- 49 -
1067'~5~
Example 23
Example 19 is repeated except that about 20.8
parts of invert sugar and about 144.2 parts of the boro-
nated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensile strength
samples using the standard procedure. The tensile
strenyth of the test bars and core hardness are set forth
below in Table VI. The composition has a work time of
about 10 minutes and a strip time of about 47 minutes.
Example 24
Example 19 is repeated except that about 25.6
parts of invert sugar and about 139.6 parts of the boronated
aluminum phosphate are employed. The resulting foundry mix
is formed into standard AFS tensile strength samples using
the standard procedure. The tensile strength of the test
bars and core hardness are set forth below in Table VI.
The composition has a work time of about 12 minutes and a
strip time of about 45 minutes.
Example 25
Example 19 is repeated except that 165 parts of
the aluminum phosphate without any invert sugar are employed.
The resulting foundry mix is formed into standard AFS tensile
Strength samples using the standard procedure. The tensile
strength of the test bars and core hardness are set forth be-
low in Table VI. The composition has a work time of about 14
minutes and a strip time of about 40 minutes.
- 50 -
~067Z53
Table VI
Example 19 Example 20
% of invert sugar
based upon total
invert sugar and 3.0 6.0
boronated alumi-
num phosphate
solution
Work time
~minutes) 12 . 10
Strip time
(minutes) 42 41
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
pgi pgi
2 140 95 120 95
4 185 95 155 92
6 195 98 210 95
24 185 90 195 85
48 140 85 170 92
72 130 80 175 90
96
51
1067'~53
Table VI
(Continued)
Example 21 Example 22
% of invert sugar
based upon total
invert sugar and 8.5 11.0
boronated alumi-
num phosphate
solution
Work time
(minute~) 10 11
Strip time
(minutes) 44 45
Time (hours) Tensile Core Tensile Core
~trength hardness strength hardness
psi psi
2 115 97 115 95
4 200 95 155 95
6 185 90
24 200 95 195 90
48 230 88 200 80
72 190 84 22S 90
96 225 90
1067253
Table VI
(Continued)
Example 23 Example 24
% of invert sugar
based upon total
invert sugar and 13.0 15.5
boronated alumi-
num phosphate
solution
Work time
(minutes) 10 12
Strip time
(minutes) 47 45
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 95 95 95 85
4 170 90 180 86
24 195 85 160 80
48 225 80 170 80
72 220 90 165 ~4
96 190 78 185 85
53
~06 7Z53
Table VI
(Continued)
Example 25
% of invert sugar
based upon total
invert sugar and 0
boronated alumi-
num phosphate
solution
Work time
(minutes) 14
Strip time
(minutes) 40
Time (hours) Tensile Core
strength hardness
psi
2 130 95
4 190 go
6 215 85
24 85 72
48 110 67
72 90 74
96
54
~067Z'S3
ExamPle 26
5000 parts of Port Crescent Lake sand and about
25 parts of a mixture of magnesium oxide having a surface
area of about 2~3 m2/gm (Magmaster l-A) and calcium alumi-
nate (Refcon) in a ratio of 5 parts of magnesium oxide to
1 part of calcium aluminate are admixed for about 2 minutes.
To this mixture are added a mixture of about 160 parts of
an aluminum phosphate prepared along the lines of the pro-
cedure in Example 1 and having a solids content of 66.6%,
viscosity of 700-750 centipoises, mole ratio of phosphorus
to total moles of aluminum and boron of 3:1, about 20 mole
% boron based upon the moles of aluminum, pH of 1.5-2.0 and
Gardner color of 2, and about 5 parts of sucrose. The mix-
ture is then agitated for 2 minutes.
The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness are
set forth below in Table VII. The composition has a work
time of about 13 minutes and a strip time of 45 minutes.
Example 27
Example 26 is repeated except that about 10 parts
of sucrose and about 155 parts of the boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars and core
- 55 -
~06725;~
hardness are set forth below in Table V~I. The composi~ion
has a work time of about 11 minutes and a strip time of
about 55 minutes.
Example 28
Example 26 is repeated except that about 14 parts
of sucrose and about 151 parts of the boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars and core
hardness are set forth below in Table VII. The composition
has a work time of about 12 minutes and a strip time of
about 50 minutes.
Example 29
Example 26 is repeated except that about 18 parts
of sucrose and about 147 parts of the boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars and core
hardness are set forth below in Table VII. The composition
has a work time of about 11 minutes and a strip time of
about 45 minutes.
- 56 -
1()67Z5;~
ExamPle 30
Example 26 is repeated except that about 20.8 parts
of sucrose and about 144.2 parts of the boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars and core
hardness are set forth below in Table VII. The composition
has a work time of about 9 minutes and a strip time of about
45 minutes.
Example 31
Example 26 is repeated except that about 25.6 parts
of sucrose and about 139.6 parts of the boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars and core
hardness are set forth bëlow in Table VII. The composition
has a work time of about 11 minutes and a strip time of about
- 46 minutes.
Example 32
Example 26 is repeated except that 165 parts of the
boronated aluminum phosphate without any sucrose are employed.
The resulting foundry mix is formed into standard AFS tensile
strength samples using the standard procedure. The tensile
strength of the test bars and core hardness are set forth be-
low in Table VII. The composition has a work time of about 14
minutes and a strip time of about 40 minutes.
- 57 -
1067Z53
Table VII
Example 26 Example 27
% of sucrose based
upon total of
sucrose and boro- 3.0 6.0
nated aluminum phos-
phate solution
Work time
(minutes) 13 11
Strip time
(minutes) 45 55
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
p~i psi
2 135 93 ~15 95
4 205 88 155 85
6 215 98 205 84
24 200 82 165 78
48 135 90 135 85
72 100 80 120 72
58
~()67253
Table VII
(Continued)
Example 28 Example 29
% of sucrose based
upon total of
sucrose and boro- 8.5 11.0
nated aluminum
phosphate solution
Work time
(minutes) 12 11
Strip time
(minutes) 50 45
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
p~i psi
2 115 93 145 88
4 170 88
24 190 88 150 75
48 165 88 170 75
72 155 78 180 75
59
10672S3
Table VII
(Continued)
Example 30 Example 31
% of sucrose based
upon total of
sucrose and boro-13~0 15.5
nated aluminum
phosphate solution
Work time
(minutes) 9 11
Strip time
(minutes) 45 46
Time (hours)Tensile Core Tensile Core
strength hardness strength hardness
p~i psi
2 170 95 125 95
4 190 90
6 190 90
24 190 82 195 85
48 185 88 195 ~ 83
72 180 85
1~)67~53
Table VII
(Continued)
Example 32
% of sucrose based
upon total of
sucrose and boro- 0
nated aluminum
phosphate solution
Work time
(minutes) 14
Strip time
(minutes) 40
Time (hours) Tensile Core
strength hardness
psi
2 130 95
4 190 90
6 215 85
24 85 72
48 110 67
72 90 74
61
~067Z53
Example 33
5000 parts of Wedron 5010 sand and about 30 parts
of a mixture of magnesium oxide having a surface area of
about 2.3 m2/gm (Magmaster l-A) and calcium aluminate (Refcon)
in a ratio of 5 parts of magnesium oxide to 1 part of calcium
aluminate are admixed for about 2 minutes. To this mixture
are added a mixture of about 163.2 parts of an aluminum phos-
phate prepared along the lines of the procedure in Example 1
and having a solids content of 66.6%, viscosity of 700-750
centipoises, mole ratio of phosphorus to total moles of alum-
inum and boron of 3:1, about 20 mole % boron based upon the
moles of aluminum, pH of 1.5-2.0 and Gardner color of 2, and
about 1.8 parts of sorbitol. The mixture is then agitated
for 2 minutes.
The resulting foundry mix is formed with standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars is set ~orth below in
Table VIII.
Example 34
Example 33 is repeated except that about 5.3 parts
of sorbitol and about lS9.7 parts of t~ boronated aluminum
phosphate are employed. The resulting foundry mix is formed
into standard AFS tensile strength s~mples using the standard
procedure. The tensile strength of the test bars is set forth
below in 'rable VIII.
62
1067ZS3
Example 35
Example 33 is repeated except that about 10.2
parts of sorbitol and about 154.8 parts of the boronated
aluminum phosphate are employed, The resulting foundry
mix is formed into standard AFS tensile strength samples
using the standard procedure. The tensile strength of
the test bars is set forth below in Table VIII.
Example 36
Example 33 is repeated except that about 13.5
parts of sorbitol and about 151.5 parts of the boronated
aluminum phosphate are employed. The resulting foundry
mix is formed into standard A~S tensile strength samples
using the standard procedure. The tensile strength of
the test bars is set forth below in Table VIII.
Example 37
Example 33 is repeated except that about 16.5
parts of sorbitol and about 148.5 parts of the boronated
aluminum phosphate are employed. The resulting foundry
mix is formed into standard AFS tensile strength samples
using the standard procedure. The tensile strength of
the t~st~ bars is set forth below in Table VIII.
- 63 -
1067Z53
Example 38
Example 33 is repeated except that 165 parts
of the boronated aluminum phosphate without any sorbitol
are employed. The resulting foundry mix is formed into
standard AFS tensile strength samples using the standard
procedure. The tensile strength of the test bars is set
forth below in Table VIII.
64
~67Z53
Table VIII
Example 33 ExamPle 34
% sorbitol based
upon total of
sorbitol and boro- 1.1 3.2
nated aluminum
phosphate solution
Time Tensile Average Tensile Averag~
~hours) strength of strength of
psi samples psi samples
295 120
24 280 292 270 183
300 160
245 225
48 190 228 175 210
250 230
215 1~5
72 275 230 175 163
200 170
250 245
120 270 228 185 198
165 165
:~!67,~53
Table VIII
tCont.inued)
Example 35 Example 36
% sorbitol based
upon total of
sorbitol and boro- 6.2 8.2
nated aluminum
phosphate solution
Time Tensile Average Tensile Average
(hours) strer.gth of strength of
psi samples psi samples
200 150
24 2'~0 210 165 168
200 _ 190
195 195
48 230 225 225 2~3
250 220
270 150
72 245 255 150 163
_ 250 185
260 260
120 265 242 185 202
200 160
66
~67253
Table VIII
(Continued)
Example 37 Example 38
% sorbitol based
upon total of
sorbitol and boro- 10 0
nated aluminum
phosphate solution
Time Tensile Average Tensile Average
(hours) strength of stren~th of
p~i samples psi samples
145 225
24 200 185 105 212
210 2400
48 235 237 165 187
252 19855
72 255 235 185 207
210 250
220 155
120 230 232 150 157
245 165
67
~06~253
The following Examples 39 and 40 demonstrate
the improved tensile strength achieved by employing the
- polyhydric alcohols when the samples are baked rather
than cured at room temperature. The baking up to about
30 minutes provided improved tensile strength for the
sorbitol containing samples.
Example 3~
5000 parts of Wedron 5010 sand and about 30 parts
of a mixture of magnesium oxide having a surface area of
about 2.3 m /gram (Magmaster l-A) and calcium aluminate
(Refcon) in a ratio of 5 parts of magnesium oxide to 1 part
of calcium aluminate are admixed for about 2 minutes. To
this mixture are added a mixture of about 151.5 parts of
an aluminum phosphate prepared along the lines of the pro-
cedure in Example 1 and having a solids content of 66.6%,
viscosity of 700-750 centipoises, mole ratio of phosphorus
to total moles of aluminum and boron of 3:1, about 20 mole
% boron based upon the moles of aluminum, pH of 1.5-2.0 and
Gardner color of 2, and about 13.5 parts Of sorbitol. The
mixture is then agitated for 2 minutes.
The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The test bars are heated at about 350 F for the different
times set forth below in Table IX. The tensile strengths of
the test bars are set forth below in Table IX.
- 68 -
1()6~253
Example 40
Example 39 is repeated except that 165 parts
of the boronated aluminum phosphate without any sorbitol
are employed. The resulting foundry mix is formed into
standard AFS tensile strength samples using the standard
procedure. The tests are heated at about 350 F for the
different times set forth below in Table IX. The tensile
strengths of the test bars are set forth below in Table IX.
69
1(~67ZS3
Table IX
Example 39 Example 40
% sorbitol based
upon total of sor-
bitol and boronated 8.2 0
aluminum phosphate
solution
TensileAverage Tensile Average
strengthof strength of
1 h~urthree 1 hour three
after strip samples after strip samples
psi psi
Baked at 350 F 375 235
for 15 minutes 310 347 255 243
355 _ 240
Baked at 350 F 255 110
for 30 minutes 295 283 205 165
300 185
Baked at 350 F 165 185
for 45 minutes 170 187 200 190
225 185
~0672S3
ExamPle 41
To a reaction vessel equipped with a stirrer,
thermometer, and reflux condenser are added about 2445 parts
of 85% phosphoric acid. Then about 67 parts of sodium borate
~ ;
are added with agitation, and the agitation is continued for
about 10 minutes until the borate dissolves in the acid to form
a clear solution. To this solution are added about 540 parts
of hydrated alumina (Alcoa C-33) under agitation. The reaction
proceeds for about 40 minutes with the temperature rising to
a maximum of about 220 F due to the reaction exotherm. Then
external heat is applied and reaction temperature rises to a
maximum of about 245 F. The reaction mass is held at about
245 F for about 2 hours to ensure complete reaction. The
reaction mass is then cooled to room temperature and about 3052
parts of a boronated aluminum phosphate having a solids content
of about 75%, a viscosity of about 40,000 centipoises, a mole
ratio of phosphorus to total moles of aluminum and boron
of 3:1 and about 10 mole % boron based upon the moles of -
~aluminum are obtained. This aluminum phosphate is diluted
with water to provide a solids content of about 66% and having
a viscosity of 400-500 centipoises.
5000 parts of Port Crescent Lake sand and about 30.5
parts of a mixture of magnesium oxide tMagmaster l-A) and a
calcium aluminate containing 58% A12O3 and 33% Cao (Refcon) in
a ratio of 5 parts of magnesium oxide to 1 part of calcium al-
uminat,e are mixed for about 2 minutes. To this mixture are
added a mixture of about 151.5 parts of the 66% solids solution
- 71 -
1~167253
of the boronated aluminum phosphate prepared above and about
13.5 parts of sorbitol. The mixture is then agitated for 2
minutes.
The resulting foundry mix is formed by hand ram-
ming into standard AFs tensile strength using the standard
procedure. The tensile strengths and core hardness of the
test bars are presented below in Table X. The work time of
the composition is 13 minutes and the strip time is 45 min-
utes.
ExamPle 42
Example 41 is repeated except that about 8.4 parts
of d-tartaric acid and about 156.6 parts of the boronated alum-
inum phosphate are employed. The resulting foundry mix is
formed into standard AFS tensile strength samples using the
standard procedure. The tensile strength of the test bars and
core hardness are set forth below in Table X. The composition
has a work time of about 11 minutes and a strip time of about
32 minutes.
Example 43
Example 41 is repeated except that 165 parts of the
boronated aluminum phosphate without any polyhydric alcohol
are employed. The resulting foundry mix is formed into stand-
ard AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness are
set forth below in Table X. The composition has a work time
of about 13 minutes and a strip time of about 42 minutes.
- 72 -
l~U67253
Table X
Example 41 Example 42 Example 43
8.2% 5.1% 0% poly-
sorbitol tartaric acid hydric alcohol
Work
time 13 11 13
(min)
Strip
time 45 32 42
(min)
Time Tensile Core Tensile Core Tensile Core
(hrs) strength hardness strength hardness strength hardness
p9i pSi psi
2 125 65 115 72 125 75
4 180 69 145 165 72
6 155 68 160 74
24 165 64 110 65 120 65
48 165 62 110 76
~067253
Example 44
Example 41 is repeated except that a boronated
aluminum phosphate containing 20 mole % boron and 20 mole
% sodium based upon the aluminum and prepared according
to the procedure of Example 41 is employed. The result-
ing foundry mix is formed by hand ramming into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core hardness
are set forth below in Table XI. The composition has a
worX time of about 15 minutes and a strip time of about 38
minutes.
Example 45
Example 44 is repeated except that about 8.4
parts of d-tartaric acid and about 156.6 parts of the
boronated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensile strength
samples using the standard procedure. The tensile strength
of the test bars and core hardness are set forth below in
Table XI. The composition has a work time of about 12
minutes and a strip time of about 30 minutes.
Example 46
Example 44 is repeated except that 165 parts of
the boronated aluminum phosphate without any polyhydric
alcohol are employed. The resulting foundry mix is formed
74
~al67'~,53
into standard AFS tensile strength samples using the
standard procedure. The tensile strength of the test
bars and core hardness are set forth below in Table XI.
The composition has a work time of about 15 minutes
and a strip time of about 38 minutes.
~067Z53
Table XI
Example 44 Example 45 Example 46
8.2% 5.1% 0% p~ly-
sorbitol tartaric acid hydric alcohol
Work
time 12 12 15
(min)
Strip
time 39 30 38
(min)
Time Tensile Core Tensile Core Tensile Core
(hrs) strength hardness strength hardness strength hardness
psi psi psi
2 120 79 105 74 100 58
4 170 76 150 69 155 77
6 185 75 170 78 110 50
24 215 71 185 67 65 32
48 225 78 155 68
7~
10~;7ZS3
A comparison of Examples 1 and 2 with 3; Examples
4 and 5 with 6; Examples 7 and 8 with 9; Examples 10-12 with
13; Examples 14-17 with 18; Examples 19-24 with 25; Examples
26-31 with 32; Examples 33-37 with 38; Example 39 with 40;
Examples 41 and 42 with 43; and Examples 44 and 45 with 46
demonstrates that after storage for several hours, the gen-
eral trend is improvement in physical properties such as
tensile strength and core hardness due to the presence of
the type of polyhydric materials employed in the present
10 invention, although a few of the samples do not fit the
general behavior due to some normal experimental error.
A lthough the systems of the present invention may not
possess as great initial physical properties as those cor-
responding systems which do not include the polyhydric ma-
terials, the higher physical properties after storage for
several hours is quite important from a practical and com-
mercial viewpoint.
The following Examples 47-55 demonstrate that
- the use of polyhydric alco~ols outside the scope of the
20 present invention does not result in the type of improved
tensile strengths as is obtained by practicing the present
invention. For instance, the polyhydrics employed in the
following examples are not solid and/or do not contain at
least two adjacent carbon atoms each having directly at-
tached thereto one hydroxyl group.
-- 77 --
~1)67ZS3
Example 47
' 5000 parts of Port Crescent Lake sand and about 25
parts of a mixture of magnesium oxide having a surface area
of about 2,3 m /gram (Magmaster l-A) and calcium aluminate
(Refcon) in a ratio of 5 parts of magnesium oxide to 1 part
of calcium aluminate are admixed for about 2 minutes. To
this mixture are added a mixture of about 156.65 parts
of an aluminum phosphate prepared along the lines of the pro-
cedure in Example 1 and having a solids content of 66.6%,
viscosity 700-750 centipoises, mole ratio of phosphorus to
total moles of aluminum and boron of 3:1, about 20 mole %
boron based upon the moles of aluminum, pH of 1.5 - 2.0 and
Gardner color of 2, and about 8.35 parts of 1,4 - butanedoil.
The mixture is then agitated for 2 minutes.
The resulting foundry mix is formed into standard
AFS tensile strength samples using the standard procedure.
The tensile strength of the test bars and core are set forth
below in Table XII. The composition has a work time of about
26 minutes and a strip time of about 78 minutes.
ExamPle 48
Example 47 is repeated except that about 13.5 parts
of 1,4-butanedoil and about 151.5 parts of the boronated alu--
minum phosphate are employed. The resulting foundry mix
is formed into standard AFS tensile strength samples
using the standard procedure. The tensile strength of the
- 78 -
~067253
test bars and core hardness are set forth below in Table
XII. The composition has a work time of about 32 minutes
and a strip time of about 90 minutes.
Example 49
Example 47 is repeated except that about 8.35
parts of l,6-hexanediol and about 156.65 parts of the bor-
onated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensile strength
samples using the standard procedure. The tensile strength
of the test bars and core hardness are set forth below in
Table XII. The composition has a work time of about 19
minutes and a strip time of 74 minutes .
Example 50
Example 47 is repeated except that about 13.5
parts of l,6-hexanediol and about 151.5 parts of the boro-
nated aluminum phosphate are employed. The resulting foun-
dry mix is formed into standard AFS tensile strength samples
using the standard procedure. The tensile strength of the
test bars and core hardness are set forth below in Table XII.
The composition has a work time of about 17 minutes and a
strip time of about 62 minutes.
Example 51
Example 47 is repeated except that about 8.35 parts
79
~L067Z53
of trimethylolpropane and about 156.65 parts of the boro-
nated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensile strength
samples using the standard procedure. The tensile strength
of the test bars and core hardness are set forth below in
Table XII. The composition has a work time of about 23
minutes and a strip time of about llO minutes.
Example 52
Example 47 is repeated except that about 13,5
parts of trimethylolpropane and about 151.5 parts of the
boronated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensile strength
samples using the standard procedure. The tensile strength
of the test bars and core hardness are set forth below in
Table XII. The composition has a work time of about 36
minutes and a strip time of about 76 minutes.
Example 53
Example ~7 is repeated except that about 8.35
parts of neopentylglycol and about 156.65 parts of the
boronated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensil strength
samples using the standard procedure. The tensile strength
of the test bars and core hardness are set forth below in
Table XII. The composition has a work time of about 27
minutes and a strip time of about 81 minutes.
llQ67Z53
Example 54
Example 47 is repeated except that about 13.5
parts of neopentylglycol and about 151.5 parts of the
boronated aluminum phosphate are employed. The resulting
foundry mix is formed into standard AFS tensi~ strength
samples using the standard procedure. The tensile strength
of the test bars and core hardness are set forth below in
Table XII. The composition has a work time of about 24
minutes and a strip time of about 67 minutes.
Ex~mple 55
Example 47 is repeated except that 165 parts of
the boronated aluminum phosphate without any alcohol are
employed. The resulting foundry mix is formed into stand-
ard AFS tensile strength samples using the standard pro-
cedure. The tensile strength of the test bars and core
hardness are set forth below in Table XII. The composition
has a work time of about 14 minutes and a strip time of
about 40 minutes.
81``
11~67Z53
Table XII
Example 47 Example 48
% polyhydric alcohol
based upon total of
alcohol and aluminum 5.06 8.2
phosphate solution
Work time
(minutes) 26 32
Strip time
(minutes) 78 90
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 65 65 55 45
6 95 70 80 52
24 110 67 60 48
48 105 72 75 42
72 100 70 65 40
82
~067ZS3
Table XII
(Continued)
Example 49 Exa~ple 50
% polyhydric alcohol
based upon total of
alcohol and aluminum 5.06 8.2
phosphate solution
Work time
(minutes) 19 17
Strip time
(minutes) 74 62
Time (hours) Tensile Core Tensile Core
stren~th hardness strength hardness
p9 i pS i
4 80 50 75 50
6 80 48 60 35
24 45 0 60 0
48 35 0 55 0
72
~3
~067253
Table XII
~Continued)
Example 51 ExamPle 52
% polyhydric alcohol
based upon total of
alcohol and aluminum 5.06 8.2
phosphate solution
Work time
(minutes) 23 36
Strip time
(minutes) 110 76
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 55 80
4 1~0 74
24 95 60 110 82
4~ 55 33 50 12
72
84
~.067Z53
Table XII
(Continued)
Example 53 Example 54
% polyhydric alcohol
based upon total o~
alcohol and aluminum 5.06 8.2
phosphate solution
Work time
(minutes) 27 24
Strip time
(minutes) 81 67
Time (hours) Tensile Core Tensile Core
strength hardness strength hardness
psi psi
2 75 45 65 3g
6 85 20
24 50 10 85 20
48 50 10
72
1067Z53
.
Table XII
(Continued)
Example 55
% polyhydric alcohol
based upon total of
alcohol and aluminum 0
phosphate solution
Work time
(minutes) 14
Strip time
(minutes) 40
Time (hours) Tensile Core
strength hardness
psi
2 130 95
4 190 90
6 215 85
24 85 72
48 110 67
72 90 74
86
