CA1067253A - Binder composition containing alcohol - Google Patents
Binder composition containing alcoholInfo
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- CA1067253A CA1067253A CA253873A CA253873A CA1067253A CA 1067253 A CA1067253 A CA 1067253A CA 253873 A CA253873 A CA 253873A CA 253873 A CA253873 A CA 253873A CA 1067253 A CA1067253 A CA 1067253A
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- binder composition
- aluminum phosphate
- minutes
- aluminum
- alkaline earth
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Abstract
BINDER COMPOSITION CONTAINING ALCOHOLS
Abstract of the Disclosure A binder composition comprising boronated aluminum phosphate, water, material containing an alkaline earth metal and an oxide, and certain solid polyhydric alcohols.
Abstract of the Disclosure A binder composition comprising boronated aluminum phosphate, water, material containing an alkaline earth metal and an oxide, and certain solid polyhydric alcohols.
Description
_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 ~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, ~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.
~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.
~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 ~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 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 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, - 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 \
~(~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 -- `~
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 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 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 ~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 ~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.
~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.
~)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, ~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 ~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 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 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.
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
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 ~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, ~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.
~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.
~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 ~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 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 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, - 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 \
~(~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 -- `~
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 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 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 ~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 ~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.
~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.
~)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, ~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 ~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 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 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.
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 2g 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 . 30 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.
'~ 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 ~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 24 lO0 69 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 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 ~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 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 ~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.
~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 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 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 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.
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.
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 48 ~ 220 88 225 85 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 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 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 ~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.
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.
~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 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 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 72 220 90 165 ~4 ~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 4 190 go ~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 ~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.
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.
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 ~()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 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 48 185 88 195 ~ 83 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 ~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.
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.
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.
~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 215 1~5 :~!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 24 2'~0 210 165 168 200 _ 190 48 230 225 225 2~3 _ 250 185 ~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 ~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.
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.
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 Baked at 350 F 165 185 for 45 minutes 170 187 200 190 ~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 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.
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 ~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 ~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 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.
~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 ~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 ~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 ~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 ~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 4 1~0 74 4~ 55 33 50 12 ~.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 .
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
(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 . 30 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.
'~ 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 ~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 24 lO0 69 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 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 ~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 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 ~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.
~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 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 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 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.
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.
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 48 ~ 220 88 225 85 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 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 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 ~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.
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.
~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 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 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 72 220 90 165 ~4 ~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 4 190 go ~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 ~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.
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.
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 ~()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 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 48 185 88 195 ~ 83 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 ~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.
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.
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.
~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 215 1~5 :~!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 24 2'~0 210 165 168 200 _ 190 48 230 225 225 2~3 _ 250 185 ~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 ~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.
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.
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 Baked at 350 F 165 185 for 45 minutes 170 187 200 190 ~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 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.
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 ~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 ~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 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.
~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 ~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 ~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 ~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 ~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 4 1~0 74 4~ 55 33 50 12 ~.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 .
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
Claims (25)
1. Binder composition which comprises:
(A) aluminum phosphate containing boron in an amount up to about 40 mole %
based upon the moles of aluminum and containing a mole ratio of phosphorus to total moles of aluminum and boron of about 2:1 to about 4:1;
(B) solid polyhydric alcohol soluble in aqueous solutions of the aluminum phosphate, and containing at least 2 adjacent carbon atoms each having directly attached thereto one hydroxyl group; and keto tautomers thereof;
(C) alkaline earth metal material contain-ing alkaline earth metal and an oxide;
and (D) water;
wherein the amount of aluminum phosphate is from about 50 to about 95% by weight based upon the total weight of aluminum phosphate and alkaline earth material; the amount of alka-line earth material is from about 50 to about 5% by weight based upon the total weight of aluminum phosphate and alka-line earth material; the amount of water is from about 15 to about 50% by weight based upon the total weight of aluminum phosphate and water; and the amount of said alcohol is from about 0.5 to about 25% by weight based upon the total weight of aluminum phosphate and alcohol.
(A) aluminum phosphate containing boron in an amount up to about 40 mole %
based upon the moles of aluminum and containing a mole ratio of phosphorus to total moles of aluminum and boron of about 2:1 to about 4:1;
(B) solid polyhydric alcohol soluble in aqueous solutions of the aluminum phosphate, and containing at least 2 adjacent carbon atoms each having directly attached thereto one hydroxyl group; and keto tautomers thereof;
(C) alkaline earth metal material contain-ing alkaline earth metal and an oxide;
and (D) water;
wherein the amount of aluminum phosphate is from about 50 to about 95% by weight based upon the total weight of aluminum phosphate and alkaline earth material; the amount of alka-line earth material is from about 50 to about 5% by weight based upon the total weight of aluminum phosphate and alka-line earth material; the amount of water is from about 15 to about 50% by weight based upon the total weight of aluminum phosphate and water; and the amount of said alcohol is from about 0.5 to about 25% by weight based upon the total weight of aluminum phosphate and alcohol.
2. The binder composition of claim 1 wherein said aluminum phosphate contains boron in an amount from about 3 to about 30 mole % based upon the moles of aluminum.
3. The binder composition of claim 1 wherein said aluminum phosphate contains boron in an amount from about 5 to about 30 mole % based upon the moles of aluminum.
4. The binder composition of claim 1 wherein said aluminum phosphate contains boron in an amount from about 10 to about 25 mole % based upon the moles of aluminum.
5. The binder composition of claim 1 wherein the aluminum phosphate contains a mole ratio of phosphorus to total moles of aluminum and boron of from about 2.5:1 to about 3.5:1.
6. The binder composition of claim 1 wherein the aluminum phosphate contains a mole ratio of phosphorus to total moles of aluminum and boron of from about 2.8:1 to about 3.2:1.
7. The binder composition of claim 1 wherein said aluminum phosphate contains boron in an amount between about 10 and about 25 mole % based upon the moles of aluminum, and wherein the mole ratio of phosphorus to total moles of alumi-num and boron is between about 2.8:1 to about 3.2:1.
8. The binder composition of claim 1 wherein the amount of said aluminum phosphate is from about 65 to about 90% by weight based upon the total weight of aluminum phos-phate and alkaline earth material, and the amount of alka-line earth material is from about 10 to about 35% by weight based upon the total weight of aluminum phosphate and alka-line earth material.
9. The binder composition of claim 1 wherein said solid polyhydric alcohol contains 2 to about 20 carbon atoms.
10. The binder composition of claim 1 wherein said solid polyhydric alcohol contains from about 2 to about 10 carbon atoms.
11. The binder composition of claim 1 wherein said polyhydric alcohol contains from about 2 to about 20 hydroxyl groups.
12. The binder composition of claim 1 wherein said solid polyhydric alcohol contains from about 2 to about 10 hydroxyl groups.
13. The binder composition of claim 1 wherein said polyhydric alcohol is selected from the group consisting of sorbitol, sucrose, invert sugar, D-glucose, .beta.-glucose, di-hydroxy succinic acid, gluconic acid, 1,2,6-hexanetriol, and mixtures thereof.
14. The binder composition of Claim 1 wherein said solid polyhydric alcohol is sorbitol.
15. The binder composition of claim 1 wherein said solid polyhydric alcohol is dihydroxy succinic acid.
16. The binder composition of claim 1 wherein the amount of polyhydric alcohol is from about 2 to about 15% by weight based upon the total weight of the aluminum phosphate and alcohol.
17. The binder composition of claim 1 wherein said alkaline earth material includes a free alkaline earth metal oxide or a free alkaline earth metal hydroxide and wherein said oxide or hydroxide has a surface area no greater than about 8.5 m2/gram (measured by the BET
procedure).
procedure).
18. The binder composition of claim 17 wherein said alkaline earth metal oxide or free alkaline earth metal hydroxide has a surface area no greater than about 3 m2/gram.
19. The binder composition of claim 1 wherein said alkaline earth metal material is 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 and wherein said alkaline earth mater-ial has a surface area no greater than about 8.5 m2/gram.
20. The binder composition of claim 19 wherein said alkaline earth metal oxide is magnesium oxide.
21. The binder composition of claim 19 wherein said mixture contains from about 2 to about 8 parts by weight of the free alkaline earth metal oxide per part by weight of the material containing a constituent in combina-tion with the oxide and alkaline earth metal.
22. The binder composition of claim 1 wherein the amount of water is from about 20 to about 40% by weight based upon the total weight of the aluminum phosphate and water.
23. Process for casting of relatively low melting point non-ferrous type metal which comprises fabricating a shape from a composition which comprises a major amount of aggregate and an effective bonding amount up to about 40%
by weight of the aggregate of the binder composition of claim 1; pouring said relatively low melting point non-ferrous type metal while in the liquid state into said shape; allowing said non-ferrous type metal to cool and solidify; contact-ing said shape with water in an amount and for a time suf-ficient to cause degradation of the bonding characteristics of the binder system; and then separating the molded article.
.lambda.
by weight of the aggregate of the binder composition of claim 1; pouring said relatively low melting point non-ferrous type metal while in the liquid state into said shape; allowing said non-ferrous type metal to cool and solidify; contact-ing said shape with water in an amount and for a time suf-ficient to cause degradation of the bonding characteristics of the binder system; and then separating the molded article.
.lambda.
24. Molding composition which comprises:
(A) a major amount of aggregate; and (B) an effective bonding amount up to about 40% by weight of the aggre-gate of the binder composition of claim 1.
(A) a major amount of aggregate; and (B) an effective bonding amount up to about 40% by weight of the aggre-gate of the binder composition of claim 1.
25. Process for casting of ferrous type metal which comprises fabrication a shape from a composition which comprises a major amount of aggregate and an effective bonding amount up to about 40% by weight of the aggregate of the binder composition of claim 1; pouring said ferrous type metal while in the liquid state into said shape; allowing said ferrous type metal to cool and solidify; degrading the bonding charac-teristics of the binder system; and then separating the molded article.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA253873A CA1067253A (en) | 1976-06-01 | 1976-06-01 | Binder composition containing alcohol |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA253873A CA1067253A (en) | 1976-06-01 | 1976-06-01 | Binder composition containing alcohol |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1067253A true CA1067253A (en) | 1979-12-04 |
Family
ID=4106107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA253873A Expired CA1067253A (en) | 1976-06-01 | 1976-06-01 | Binder composition containing alcohol |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1067253A (en) |
-
1976
- 1976-06-01 CA CA253873A patent/CA1067253A/en not_active Expired
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