CA1168831A - Process of forming foundry cores and molds utilizing binder curable by free radical polymerization - Google Patents
Process of forming foundry cores and molds utilizing binder curable by free radical polymerizationInfo
- Publication number
- CA1168831A CA1168831A CA000367602A CA367602A CA1168831A CA 1168831 A CA1168831 A CA 1168831A CA 000367602 A CA000367602 A CA 000367602A CA 367602 A CA367602 A CA 367602A CA 1168831 A CA1168831 A CA 1168831A
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- Canada
- Prior art keywords
- binder material
- binder
- ethylenically unsaturated
- monomer
- polymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
- C08F290/08—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated side groups
- C08F290/14—Polymers provided for in subclass C08G
- C08F290/147—Polyurethanes; Polyureas
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
- B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
- B22C1/20—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents
- B22C1/22—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of organic agents of resins or rosins
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Mold Materials And Core Materials (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Macromonomer-Based Addition Polymer (AREA)
- Polymerization Catalysts (AREA)
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
- Polymerisation Methods In General (AREA)
Abstract
PROCESS OF FORMING FOUNDRY
CORES AND MOLDS UTILIZING
BINDER CURABLE BY FREE RADICAL
POLYMERIZATION
ABSTRACT
A binder is formed by polymerizing or hardening a binding material or composition, an unsaturated polymer or unsaturated monomer or mixtures thereof (polymer solution), wherein at least part of the unsaturation is ethylenic, preferably of vinyl or acrylic type, by free radical polymerization. The free radical polymerization is caused by contacting the unsaturated binding material with a free radical initiator comprising a peroxide and catalytic agent. In the preferred embodiment the binding material is a solution of an ethylenically unsaturated polymer in a solvent of unsaturated monomeric compound or compounds, in which vinyl or acrylic unsaturation is present. The binder is formed upon poly-merization which occurs when the unsaturated monomer, polymer or polymer solution is exposed to the free radical initiator. Sub-jection of the unsaturated monomer, polymer or polymer solution to the initiator begins the formation of free radicals and sub-sequently the binding composition is polymerized to form the binder. This binder has been found to be especially suitable as a foundry binder of the cold box type wherein a room temperature, rapid gas cure is utilized. The gas, preferably sulfur dioxide, serves as the catalytic agent of the free radical initiator.
Cores made using this binder are especially useful in casting aluminum and other lightweight metals because the binder collapses readily after casting of these metals to provide complete shake-out of the core without application of external energy. The binder also has application to make cores used in casting iron.
CORES AND MOLDS UTILIZING
BINDER CURABLE BY FREE RADICAL
POLYMERIZATION
ABSTRACT
A binder is formed by polymerizing or hardening a binding material or composition, an unsaturated polymer or unsaturated monomer or mixtures thereof (polymer solution), wherein at least part of the unsaturation is ethylenic, preferably of vinyl or acrylic type, by free radical polymerization. The free radical polymerization is caused by contacting the unsaturated binding material with a free radical initiator comprising a peroxide and catalytic agent. In the preferred embodiment the binding material is a solution of an ethylenically unsaturated polymer in a solvent of unsaturated monomeric compound or compounds, in which vinyl or acrylic unsaturation is present. The binder is formed upon poly-merization which occurs when the unsaturated monomer, polymer or polymer solution is exposed to the free radical initiator. Sub-jection of the unsaturated monomer, polymer or polymer solution to the initiator begins the formation of free radicals and sub-sequently the binding composition is polymerized to form the binder. This binder has been found to be especially suitable as a foundry binder of the cold box type wherein a room temperature, rapid gas cure is utilized. The gas, preferably sulfur dioxide, serves as the catalytic agent of the free radical initiator.
Cores made using this binder are especially useful in casting aluminum and other lightweight metals because the binder collapses readily after casting of these metals to provide complete shake-out of the core without application of external energy. The binder also has application to make cores used in casting iron.
Description
g3 /
DESCR PTION OF THE PRIOR ART
Many different types of binding materials have found use in foundry core making and mold making operations. The binding material upon hardening should impart to the core and molds various desirable properties. Examples of such propetties are errosion resistance, humidity resistance and collapsibility or shake-out. In core making or mold making, high production is also a desired goal~
- Modern core making and mold making techniques began with the use of unsaturated drying oils derived from natural products as binding material. Linseed oil is the foremost example of a drying oil. On exposure to air, linseed oil and other unsaturated oils undergo oxidatively initiated polymerizations resulting in formation of solid, highly cross-linked structures. Polymerization can be accelerated by heat or by chemical methods. These binding materials are known in the industry as core oils. In forming a core, the oil is mixed with sand and the sand mixture is shaped into the form of a core or mold. Hardening is accomplished by heating or aging the core or mold for a long period of time. Binders base on core oil, in addition to the oil component, may contain other components such as oil derived esters, unsaturated hydrocarbon resins and solvents. Core oil based procesæes ~or forming foundry shapes such as molds and cores have been known for fifty to sixty years.
Processes which are faster than the abovementioned coxe oil processes were introduced 25 to 30 years ago. These processes require heat cure for the binding material. These hot-box core processes are based upon a thermal setting resin compositions.
Chemically these thermosetting resins include phenol-~ormaldehyde resins, urea-~ormaldehyde resins and furfuryl alcohol-formaldehyde resins. In addition to using heat to cure or polymerize these binding materials, acids are often incorporated as catalysts.
About ten years ago room temperature, high spçed processes for the production of foundry cores and molds were introduced.
The binder formed by these processes is based on urethane chemistry. In essence, the binding material consists of two liquid resin components. One component is a phenol-formaldehyde resin. The second comp~nent is a polymeric isocyanate. The phenolic and the isocyanate resin are mixed with sand and may be used in either a "cold box" or a "no bake" system. In the cold box system, the sand which has been coated with the two components is blown into a core box. Once the sand mixture is blown into a core box a gaseous tertiary amine is passed through the core box to cause an instantaneous cure or svlidification to form the binder. U.S. Patent No. 3,409,579 is illustrative of this tech-3 :~ 1 nology. In no bake type core making procedure the polyisocyanate component, the phenolic resin component and a catalyst are all mi~ed with sand at the same time. The sand - mix is then poured into a core box or pattern. The sand mix remains fluid for a period of time. After this period has elapsed, the catalyst initiates the curing or polymerization and the core is rapidly formed as the binding components quickly react to form a urethane binder. No bake binders are taught by U.S. Patent No. 3,676,392.
A further binder composition and procedure for forming a foundry binder is described in U.S. Patent No. 3,879,339. In this patent there is described a cold box, i.e., room temperature, gas curable method of forming a foundry binder involving an organic resin which is acid curable and an oxidizing agent. This binding component is cured with sulphur dioxide gas. The combination of sulphur dioxide plus ~he oxidizing agent, leads to the formation of sulfuric acid, the acid serves to cure the acid curable organic resin. In essence, sulphuric acid is formed in situ and the acid reacts with tha resin. Thus curing of the binding composition is accomplished.
None of the above described foundry binders are of such utility and versatility that they are viewed as a universal or irreplaceable foundry binder. Each has advantages and disadvantages to some degree.
Therefore it is the object of the invention to provide a new binder based upon chemistry heretofore not applied in foundries or in other fields of binder use. It is a special 1 ~883~
object to provide a foundry binder of the cold box type which exhibits rapid cure. Another object is to provide a cold box binder useful in casting aluminum and other light metals.
BACKGROUND OF TE~E INVENTION
This invention relates to binders preferably cured at room temperature which are formed by mixing (a) a binding composition or material comprising ethylenically unsaturated monomers, ethylenically unsaturated polymers and blends of such unsaturated monomers, ethylenically unsaturated polymers and blends of such unsaturated monomers and polymers, and (b) a free radical initiator comprising a peroxide and a catlytic agent. In general, this invention relates to room tempera~ure curable binding compositions which are polymerizable through free radical initiation and chain extension. These binding compositions are useful in adhering materials and especially particulate solids. In particular, the invention relates to compositions which are capable of bonding sand or other aggregates to form molds or cores for casting metals, including especially aluminum and other lightweight metals. Molds and cores made using these binders demonstrate superior collapsibility when used in casting lightweight metals, i.e. t metals which are cast at low casting temperature. The curing of the binding material to form the binder composition preferably takes place at ambient temperature and is accomplished by a free radical initiator comprising a peroxide and a catalytic agent. In preferred form, the catalytic agent 3.~
is gaseous and the cure or hardening is nearly instantaneous.
However, selection of differing catalytic agents results in a variety of options for the manner and rate of cure.
DETAILS DESCRIPTION AND PREFERRED EMBODI~ENT OF INVENTION
This invention pertains to a foundry binder in which the chemistry is unlike that used to form any binder which has heretofore been known to be useful in the foundry industry.
The binder also has application as a binder or binding agent in fields other than the foundry industry. The chemistry on which this binder is based is analyagous to a degree to chemistry which has heretofore been utilized in coatings, see for example, British Patent No. 1,055,242, and adhesives, see for example various patents assigned to Loctite Corporation. An anaerobically cured foundry binder based on similar chemistry is described in Canadian Patent No. 1,053,440. This binder cures very slowly and involved the necessity of heating to accomplish cure. Applicant's invention does not encompass an anaerobic curing process and involves rapid, almost instantaneous, curing at room temperature with certain catalytic agents.
It is well known that foundry shapes, that is cores and molds, are formed by disbursing on sand or another agreegate material a binding substance or chemical, shaping the sand into the desired shape and allowing or causing the bindi~g substance or chemical to harden to form a binder. The present invention can be thought oE in terms of as a binder which results from bringing together two parts. Part I is a binding substance or 1 16~3~L
composition which undergoes polymerization and crosslinking to adhere, hold or bind the sand or other aggregate in the desired shape~ The second part (Part II) is an agent which causes the polymerization and crosslinking oE Part I to take place. This agent is referred to herein as the "free radical initiator".
As used in this description the term "crosslink" indicates a chain build up which results when a polymer is involved either by linking with another polymer or with a monomer. The "polymerization" includes "crosslink" bu-t also applies to the chain extension which involves only monomers.
Part I of the binder system can be described as an unsaturated composition which is cross linkable or polymerizable by free radical mechanixm. The unsaturation is preferably terminal or pendent. Still internal unsaturation is acceptable and polymerization will result upon combination with Part II. It is also feasible, depending upon the manner of synthesis of the Part I component, to have a Part I component having both terminal and/or pendent unsaturation and also internal unsaturation in the same component. Applicant's believe the polymerization mechanism is nearly all of the free radical type when crosslinking compositions (i.e., unsaturated polymer(sl) are involved. When certain monomers are used as the binding composition it is possible that a portion of the polymerization may take place by a mechanism other than free radical. It is to be understood therefore that the description contained herein sets forth applicant's best belie~ as to the ~ .
1 168~ 1 mechanism for polymerization and that "free radical mechanism"
is used ~or convenience and accurately describes such mechanism in nearly all instances. However, it is to be understood that in addition to the free radical mechanism other mechanisms mayt also be involved in the polymerization under certain circumstances. Curing is accomplished using Part II, a free radical initiator, which comprises a peroxide and a catalytic agent. It has been discovered that unsaturated reactive monomers, polymers and mixtures thereof (i.e., the binding composition) can be used as a binding material which is instantaneously curable upon selection oE certain catalytic agents for the free radical initiator. The unsaturation found in the monomers and polymers is preferably of the ethylenic type. For example reactive polymers~ which can also be described as oligomers or as adducts, which contain preferably vinyl or acrylic unsaturation are used as binding compositions which upon polymerization make a binder for foundry cores or molds from sand. The free radical initiator (Part II) is mixed with the reactive polymer or monomer (Part I) and f~rms free radicals which polymerize the binding composition ~o form the binder. This combination of a peroxide and a catlytic agent, which agent in addition to being chemical in nature may also be a form of energy, is referred to herein as a "free radical initiator".
The free radical initiator described herein can be used to cause polymerization of Part I materials in a number of manners. For example, the peroxide can be mixed with the Part I material and this mixture disbursed uniformly on sand. After 8 ~ 3 ~
the sand is shaped as desired, the shaped sand can be exposed to the catlytic agent. Alternatively, the catalytic agent can be added to the Part I material and this mixture used to coat sand and the coated sand then shaped as desired. The peroxide component of the free radical initiator can then be added to the shaped article and hardening through polymerization will occur. It is also possible to divide the Part I material into two portions. The catalytic agent could be added to one portion and the peroxide could be added to the second portion.
Upon combining the two portions, after applying at least one portion with the material to be bonded, polymerization occurs.
Depending upon the type of catalytic agent or equipment and application utilized this method may not be practicable.
However, if the binding materials is used to adhere non-particulate materials this last method may be particularly useful. Selection of various catalytic agents has a large influence upon the means that can be used to polymerize the binding material and upon the rate at which the binding material is cured. For example, selection of the proper catlytic agent enables the user of the binding material to instantaneously polymerize the material at room temperature or to delay the polymerization for some time and finally achieve polymeLization at elevated temperatures. The availability o~
options for selecting conditions at which the binding composition polymerizes is deemed significant.
_ g _ 'I
As clescribed above, the Part I binding material is a polymeri~able, unsaturated, monomer, polymer or mixture of such monomer(s) and such polymer(s). Examples of materials which are suitable monomeric compounds for the Part I component include a wide variety of monofunctional, difunctional, trifunctional and tetrafunctional acrylates. A representative listing of these monomers includes alkyl acrylates, hydroxyalkyl acrylates, alkoxy-alkyl acrylates r cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates alkoxyalkyl methacrylates cyanoalkyl methacrylates, N-alkoxymethylacrylamides, and N-alkoxymethylmethacrylamides.
Difunctionsl monomeric acrylates include hexanediol diacrylate and tetracethylene glycol ciacrylate. Other acrylates which can be used include trimethololpropane triacrylate, methacrylic acid and 2 ethylhexyl methacrylate. It is preferred to use poly functional acrylates when the monomer is the only binding species in the binder syste. As previously mentioned when only monomers are used as the binding material crosslinking may not occur. Also some mechanism beside a free radical mechanism may cause polymerization.
Examples of unsaturated reactive polymers which have been found to be especially useful in forming this foundry binder are epoxy acrylate reaction products, polyester./urethane/acrylate/ reaction products, polyether acrylates, and polyester acrylates. Unsaturated polymers which find use as a Part I composition include commercially available materials such as W ITHAN* 782 and 783, acrylated urethan oligomers from ~hiokol* and CMD 1700, an acrylated ester of an acrylic polymer and CELRAD 3701, an acrylated epoxy resin both available from Celanese~ Reactive polymers can be formed in a number of manners. One preferrred method of preparation of the reactive polymers is to form an isocyanate terminated prepolymer by reacting a polyhydroxy compound or polyol with a *Trade Marks . , , 3 ~
diisocyanate. The prepolymer is further reacted with a hydroxyalkyl acrylate to form an oligomer. A second approach which has been found to be beneficial is to react a polyisocyanate compound, preferably a diisocyanate compound, with an hydroxyalkyl acrylate. The reaction product is an "adduct" of these two materials. In addition oligomers and adducts may be prepared simultaneously under appropriate conditions.
In addition to the reactive unsaturated polymer, a solvent, preferably of a reactive nature, may be included and preferably is included as a component of the binding material. Depending upon the nature of the unsaturated binding material inert solvents may also be used. The preferred solvent is an unsaturated monomeric compound such as that described above in the recitation of monomeric Part I materials. Accordingly the Part I material may comprise a mixture of those unsaturated monomers and unsaturated polymer which have previously been suggested for use as Part I materials per se. Best results occur when a solution of an unsaturated reactive polymer and a monomeric unsaturated solvent is used. This combination appears to be more readily capable of copolymerization and crosslinking to form a binding matrix required either to adhere sand or other aggregates together thereby forming the foundry core or mold or to bond other materials.
As stated, it is preferred to use in Part I of the binder system an unsaturated monomeric compound as solvent in addition to the unsaturated polymer. As described above these monomers contain unsaturation and are crosslinkable with the polymer in addition to serving as a solvent for the unsaturated polymer.
8 3 ~
Any of the unsaturated monomers (or combination thereof) which were described as being useful Part I materials per se are also useful as solvents. Ethylenic unsaturation preferably of the vinyl or acrylic type, is recommended. Examples of favored monomers, to be used as solvents for the unsaturated polymers, include pentaerythritol triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, and tetraethylene glycol diacrylate which used as a solvent for the unsaturated polymer. The amount of monomer in Part I can be 0 up to 100%
based upon the total weight oE Part I binding composition.
It is possible to use the reactive polymer as the Part I
material and the free radical initiator without any solvent, including unsaturated monomer, being present for the unsaturated polymer. It is also feasible to use the unsaturated monomer as the Part I material with a free radical initiator but without the reactive polymer in order to get a polymerized binder. Neither of the two above described ~
combinations are preferred. As previously stated the preferred binder system is Part I comprising a reactive unsaturated polymer dissolved in a reactive diluent, preferably a monomeric unsaturated solvent and Part II comprising a free radicallinitiator.
The free radical initiator is comprised of two components~
The first component is preferably an organic peroxide.
However, it is contemplated that any substance can be used as the first component which will form free radicals upon exposure to a catalytic agent, could be used with the free radical polymerizable Part I binding material unsaturated polymers, monomers and mixtures thereof described above. Peroxide level can vary over wide limits depending to some extent upon the catalytic agent used. However, in general it can be said that 0.5% to 2% peroxide based upon the weight of the binding material (Part I) will produce satisfactory binding under most conditions. Examples of preferred peroxides include t-butyl hydroperoxide, cumene hydroperoxide and methyl ethyl ketone peroxide. It is worthy of note that hydroperoxides are much preferred over peroxide. Inconsistent curing has been observed using peroxide. Mixtures of peroxides and hydroperoxides and mixtures of hydroperoxides are useful The catlytic agent component of the free radical initiator is preferably chemical in nature, preferably sulfur dioxide in gaseous form. Other chemical catalytic agents which are thought to have some practical utility includ amines and NO2 Once again it should be noted that a change of the catalytic agent can have a vivid influence upon -the rate of polymerization. However, other non-chemical agents which interact with the poxide components of the free radical initiator may also be of utility. For example, heat, an approximate minimum termperature of 140F' can interact with peroxide to form free radicals which serve to polymerize the Part I materials. Increasing the temperature tends to increase the polymerication and cause faster cure. The polymerization takes place without the presence of a chemical catalytic agent.
1 ~6883~
In preferred Eoundry pactice, the unsat~rated reactive polymer, monomer or mixtures thereof and the peroxide component of the free radical initiator are mixed with sand in a conventional manner. The sand mix is then formed into a desired foundry shape by ramming, blowing or other known foundry core and mold making methods. The shaped article is then exposed to the catalytic agent component of the free radical initiator. In the preferred method of this invention gaseous S02 is used as the catalytic agent of the free radical initiator. The gas is~present only in catalytic amounts as previousl stated. The exposure time of the sand mix to the gas can be as little as 1/2 second or less and the binder component cures on contact with the catalytic agent. When S02 is used as the catalytic agent in a foundry cold box process it is suspended in a stream of carrier gas in a known manner. The carrier gas is usuallY N2. As little as 0.5% S02 based upon the weight of the carrier gas is ade~uate to cause polymerization. It is also feasible to expose S02 to the binder component without the presence of any carrier gas.
Part I may also contain optional ingredients. For example additives for wetting and defoaming may be useful. Silanes have been found to be especially useful additives. Especially preferred are unsaturated silanes, for example vinyl silanes, Advantages of this binding composition as a foundry binder are the following. The collapsibility of the binder use for casting aluminum is excellent. It has been found that this binder i, 3L1~8~3~
i11 readily co11ap~e or shake out of an al~minum casti~g with the application of a minimum of external energy. The binder also provides good strength properties. The bench life of sand mixed with Part I is lengthy. The surface finish of castings made using this binder and process has been found to be very good. The pro-duction rate of cores and molds made using this binder system is rapid especially when SO2 gas is used as the catalytic agent.
A foundry utilizing the binder composition which is described herein will mix Part I and one component of the free radical initiator, preferably the peroxide, with sand or other suitable foundry aggregate in a known manner. The sand mix is then formed into the desired foundry shape, cor~s or molds, in known manner.
The sand mix is then exposed to the second component of the free radical initiator, preferably the catalytic agent which is preferably sulfur dioxide gas, and polymerization of the Part I
binding material immediately occurs to form the binder of this invention.
The present invention is further illustrated by the following examples in which, unless otherwise indicated, all parts are by weight and all percentages are weight percentages.
EXAMPLE I
Gel tests were oonducted on various unsaturated monomers and polymers to determine their tendency to polymerize and the speed of polymerization. In carrying out the tests from about 1.5 to 2 grams of unsaturated monomer or polymer (i.e. Part I) were mixed 1 ~6~83~
with 0.03 grams of t-butylhydroperoxide (the peroxide component of the free radical initiator). This mixture was then exposed to S2 gas (the catalytic agent of the free radical initiator) either by dispersing the gas in the liquid (bubbling) or by creating an S2 atmosphere above the liquid (contacting). The results, set forth below, indicate that all unsal:urated monomers and polymers polymerize. ThUS all the listed compounds are potential binders.
Those listed compounds which demonstrated rapid polymerization or gelling are of greatest potential foundry binders for use in foundry high speed cold box mold and core ma~ing rapid.
PART I FINDING OF POLYMERIZATION
Acrylic Acid Rapid, on contact with SO2 Ethyl Acrylate Slow, on contact with SO2 n-Butyl Acrylate Slow, on contact with SO2 Isobutyl Acrylate Slow, on contact with SO2
DESCR PTION OF THE PRIOR ART
Many different types of binding materials have found use in foundry core making and mold making operations. The binding material upon hardening should impart to the core and molds various desirable properties. Examples of such propetties are errosion resistance, humidity resistance and collapsibility or shake-out. In core making or mold making, high production is also a desired goal~
- Modern core making and mold making techniques began with the use of unsaturated drying oils derived from natural products as binding material. Linseed oil is the foremost example of a drying oil. On exposure to air, linseed oil and other unsaturated oils undergo oxidatively initiated polymerizations resulting in formation of solid, highly cross-linked structures. Polymerization can be accelerated by heat or by chemical methods. These binding materials are known in the industry as core oils. In forming a core, the oil is mixed with sand and the sand mixture is shaped into the form of a core or mold. Hardening is accomplished by heating or aging the core or mold for a long period of time. Binders base on core oil, in addition to the oil component, may contain other components such as oil derived esters, unsaturated hydrocarbon resins and solvents. Core oil based procesæes ~or forming foundry shapes such as molds and cores have been known for fifty to sixty years.
Processes which are faster than the abovementioned coxe oil processes were introduced 25 to 30 years ago. These processes require heat cure for the binding material. These hot-box core processes are based upon a thermal setting resin compositions.
Chemically these thermosetting resins include phenol-~ormaldehyde resins, urea-~ormaldehyde resins and furfuryl alcohol-formaldehyde resins. In addition to using heat to cure or polymerize these binding materials, acids are often incorporated as catalysts.
About ten years ago room temperature, high spçed processes for the production of foundry cores and molds were introduced.
The binder formed by these processes is based on urethane chemistry. In essence, the binding material consists of two liquid resin components. One component is a phenol-formaldehyde resin. The second comp~nent is a polymeric isocyanate. The phenolic and the isocyanate resin are mixed with sand and may be used in either a "cold box" or a "no bake" system. In the cold box system, the sand which has been coated with the two components is blown into a core box. Once the sand mixture is blown into a core box a gaseous tertiary amine is passed through the core box to cause an instantaneous cure or svlidification to form the binder. U.S. Patent No. 3,409,579 is illustrative of this tech-3 :~ 1 nology. In no bake type core making procedure the polyisocyanate component, the phenolic resin component and a catalyst are all mi~ed with sand at the same time. The sand - mix is then poured into a core box or pattern. The sand mix remains fluid for a period of time. After this period has elapsed, the catalyst initiates the curing or polymerization and the core is rapidly formed as the binding components quickly react to form a urethane binder. No bake binders are taught by U.S. Patent No. 3,676,392.
A further binder composition and procedure for forming a foundry binder is described in U.S. Patent No. 3,879,339. In this patent there is described a cold box, i.e., room temperature, gas curable method of forming a foundry binder involving an organic resin which is acid curable and an oxidizing agent. This binding component is cured with sulphur dioxide gas. The combination of sulphur dioxide plus ~he oxidizing agent, leads to the formation of sulfuric acid, the acid serves to cure the acid curable organic resin. In essence, sulphuric acid is formed in situ and the acid reacts with tha resin. Thus curing of the binding composition is accomplished.
None of the above described foundry binders are of such utility and versatility that they are viewed as a universal or irreplaceable foundry binder. Each has advantages and disadvantages to some degree.
Therefore it is the object of the invention to provide a new binder based upon chemistry heretofore not applied in foundries or in other fields of binder use. It is a special 1 ~883~
object to provide a foundry binder of the cold box type which exhibits rapid cure. Another object is to provide a cold box binder useful in casting aluminum and other light metals.
BACKGROUND OF TE~E INVENTION
This invention relates to binders preferably cured at room temperature which are formed by mixing (a) a binding composition or material comprising ethylenically unsaturated monomers, ethylenically unsaturated polymers and blends of such unsaturated monomers, ethylenically unsaturated polymers and blends of such unsaturated monomers and polymers, and (b) a free radical initiator comprising a peroxide and a catlytic agent. In general, this invention relates to room tempera~ure curable binding compositions which are polymerizable through free radical initiation and chain extension. These binding compositions are useful in adhering materials and especially particulate solids. In particular, the invention relates to compositions which are capable of bonding sand or other aggregates to form molds or cores for casting metals, including especially aluminum and other lightweight metals. Molds and cores made using these binders demonstrate superior collapsibility when used in casting lightweight metals, i.e. t metals which are cast at low casting temperature. The curing of the binding material to form the binder composition preferably takes place at ambient temperature and is accomplished by a free radical initiator comprising a peroxide and a catalytic agent. In preferred form, the catalytic agent 3.~
is gaseous and the cure or hardening is nearly instantaneous.
However, selection of differing catalytic agents results in a variety of options for the manner and rate of cure.
DETAILS DESCRIPTION AND PREFERRED EMBODI~ENT OF INVENTION
This invention pertains to a foundry binder in which the chemistry is unlike that used to form any binder which has heretofore been known to be useful in the foundry industry.
The binder also has application as a binder or binding agent in fields other than the foundry industry. The chemistry on which this binder is based is analyagous to a degree to chemistry which has heretofore been utilized in coatings, see for example, British Patent No. 1,055,242, and adhesives, see for example various patents assigned to Loctite Corporation. An anaerobically cured foundry binder based on similar chemistry is described in Canadian Patent No. 1,053,440. This binder cures very slowly and involved the necessity of heating to accomplish cure. Applicant's invention does not encompass an anaerobic curing process and involves rapid, almost instantaneous, curing at room temperature with certain catalytic agents.
It is well known that foundry shapes, that is cores and molds, are formed by disbursing on sand or another agreegate material a binding substance or chemical, shaping the sand into the desired shape and allowing or causing the bindi~g substance or chemical to harden to form a binder. The present invention can be thought oE in terms of as a binder which results from bringing together two parts. Part I is a binding substance or 1 16~3~L
composition which undergoes polymerization and crosslinking to adhere, hold or bind the sand or other aggregate in the desired shape~ The second part (Part II) is an agent which causes the polymerization and crosslinking oE Part I to take place. This agent is referred to herein as the "free radical initiator".
As used in this description the term "crosslink" indicates a chain build up which results when a polymer is involved either by linking with another polymer or with a monomer. The "polymerization" includes "crosslink" bu-t also applies to the chain extension which involves only monomers.
Part I of the binder system can be described as an unsaturated composition which is cross linkable or polymerizable by free radical mechanixm. The unsaturation is preferably terminal or pendent. Still internal unsaturation is acceptable and polymerization will result upon combination with Part II. It is also feasible, depending upon the manner of synthesis of the Part I component, to have a Part I component having both terminal and/or pendent unsaturation and also internal unsaturation in the same component. Applicant's believe the polymerization mechanism is nearly all of the free radical type when crosslinking compositions (i.e., unsaturated polymer(sl) are involved. When certain monomers are used as the binding composition it is possible that a portion of the polymerization may take place by a mechanism other than free radical. It is to be understood therefore that the description contained herein sets forth applicant's best belie~ as to the ~ .
1 168~ 1 mechanism for polymerization and that "free radical mechanism"
is used ~or convenience and accurately describes such mechanism in nearly all instances. However, it is to be understood that in addition to the free radical mechanism other mechanisms mayt also be involved in the polymerization under certain circumstances. Curing is accomplished using Part II, a free radical initiator, which comprises a peroxide and a catalytic agent. It has been discovered that unsaturated reactive monomers, polymers and mixtures thereof (i.e., the binding composition) can be used as a binding material which is instantaneously curable upon selection oE certain catalytic agents for the free radical initiator. The unsaturation found in the monomers and polymers is preferably of the ethylenic type. For example reactive polymers~ which can also be described as oligomers or as adducts, which contain preferably vinyl or acrylic unsaturation are used as binding compositions which upon polymerization make a binder for foundry cores or molds from sand. The free radical initiator (Part II) is mixed with the reactive polymer or monomer (Part I) and f~rms free radicals which polymerize the binding composition ~o form the binder. This combination of a peroxide and a catlytic agent, which agent in addition to being chemical in nature may also be a form of energy, is referred to herein as a "free radical initiator".
The free radical initiator described herein can be used to cause polymerization of Part I materials in a number of manners. For example, the peroxide can be mixed with the Part I material and this mixture disbursed uniformly on sand. After 8 ~ 3 ~
the sand is shaped as desired, the shaped sand can be exposed to the catlytic agent. Alternatively, the catalytic agent can be added to the Part I material and this mixture used to coat sand and the coated sand then shaped as desired. The peroxide component of the free radical initiator can then be added to the shaped article and hardening through polymerization will occur. It is also possible to divide the Part I material into two portions. The catalytic agent could be added to one portion and the peroxide could be added to the second portion.
Upon combining the two portions, after applying at least one portion with the material to be bonded, polymerization occurs.
Depending upon the type of catalytic agent or equipment and application utilized this method may not be practicable.
However, if the binding materials is used to adhere non-particulate materials this last method may be particularly useful. Selection of various catalytic agents has a large influence upon the means that can be used to polymerize the binding material and upon the rate at which the binding material is cured. For example, selection of the proper catlytic agent enables the user of the binding material to instantaneously polymerize the material at room temperature or to delay the polymerization for some time and finally achieve polymeLization at elevated temperatures. The availability o~
options for selecting conditions at which the binding composition polymerizes is deemed significant.
_ g _ 'I
As clescribed above, the Part I binding material is a polymeri~able, unsaturated, monomer, polymer or mixture of such monomer(s) and such polymer(s). Examples of materials which are suitable monomeric compounds for the Part I component include a wide variety of monofunctional, difunctional, trifunctional and tetrafunctional acrylates. A representative listing of these monomers includes alkyl acrylates, hydroxyalkyl acrylates, alkoxy-alkyl acrylates r cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates alkoxyalkyl methacrylates cyanoalkyl methacrylates, N-alkoxymethylacrylamides, and N-alkoxymethylmethacrylamides.
Difunctionsl monomeric acrylates include hexanediol diacrylate and tetracethylene glycol ciacrylate. Other acrylates which can be used include trimethololpropane triacrylate, methacrylic acid and 2 ethylhexyl methacrylate. It is preferred to use poly functional acrylates when the monomer is the only binding species in the binder syste. As previously mentioned when only monomers are used as the binding material crosslinking may not occur. Also some mechanism beside a free radical mechanism may cause polymerization.
Examples of unsaturated reactive polymers which have been found to be especially useful in forming this foundry binder are epoxy acrylate reaction products, polyester./urethane/acrylate/ reaction products, polyether acrylates, and polyester acrylates. Unsaturated polymers which find use as a Part I composition include commercially available materials such as W ITHAN* 782 and 783, acrylated urethan oligomers from ~hiokol* and CMD 1700, an acrylated ester of an acrylic polymer and CELRAD 3701, an acrylated epoxy resin both available from Celanese~ Reactive polymers can be formed in a number of manners. One preferrred method of preparation of the reactive polymers is to form an isocyanate terminated prepolymer by reacting a polyhydroxy compound or polyol with a *Trade Marks . , , 3 ~
diisocyanate. The prepolymer is further reacted with a hydroxyalkyl acrylate to form an oligomer. A second approach which has been found to be beneficial is to react a polyisocyanate compound, preferably a diisocyanate compound, with an hydroxyalkyl acrylate. The reaction product is an "adduct" of these two materials. In addition oligomers and adducts may be prepared simultaneously under appropriate conditions.
In addition to the reactive unsaturated polymer, a solvent, preferably of a reactive nature, may be included and preferably is included as a component of the binding material. Depending upon the nature of the unsaturated binding material inert solvents may also be used. The preferred solvent is an unsaturated monomeric compound such as that described above in the recitation of monomeric Part I materials. Accordingly the Part I material may comprise a mixture of those unsaturated monomers and unsaturated polymer which have previously been suggested for use as Part I materials per se. Best results occur when a solution of an unsaturated reactive polymer and a monomeric unsaturated solvent is used. This combination appears to be more readily capable of copolymerization and crosslinking to form a binding matrix required either to adhere sand or other aggregates together thereby forming the foundry core or mold or to bond other materials.
As stated, it is preferred to use in Part I of the binder system an unsaturated monomeric compound as solvent in addition to the unsaturated polymer. As described above these monomers contain unsaturation and are crosslinkable with the polymer in addition to serving as a solvent for the unsaturated polymer.
8 3 ~
Any of the unsaturated monomers (or combination thereof) which were described as being useful Part I materials per se are also useful as solvents. Ethylenic unsaturation preferably of the vinyl or acrylic type, is recommended. Examples of favored monomers, to be used as solvents for the unsaturated polymers, include pentaerythritol triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, and tetraethylene glycol diacrylate which used as a solvent for the unsaturated polymer. The amount of monomer in Part I can be 0 up to 100%
based upon the total weight oE Part I binding composition.
It is possible to use the reactive polymer as the Part I
material and the free radical initiator without any solvent, including unsaturated monomer, being present for the unsaturated polymer. It is also feasible to use the unsaturated monomer as the Part I material with a free radical initiator but without the reactive polymer in order to get a polymerized binder. Neither of the two above described ~
combinations are preferred. As previously stated the preferred binder system is Part I comprising a reactive unsaturated polymer dissolved in a reactive diluent, preferably a monomeric unsaturated solvent and Part II comprising a free radicallinitiator.
The free radical initiator is comprised of two components~
The first component is preferably an organic peroxide.
However, it is contemplated that any substance can be used as the first component which will form free radicals upon exposure to a catalytic agent, could be used with the free radical polymerizable Part I binding material unsaturated polymers, monomers and mixtures thereof described above. Peroxide level can vary over wide limits depending to some extent upon the catalytic agent used. However, in general it can be said that 0.5% to 2% peroxide based upon the weight of the binding material (Part I) will produce satisfactory binding under most conditions. Examples of preferred peroxides include t-butyl hydroperoxide, cumene hydroperoxide and methyl ethyl ketone peroxide. It is worthy of note that hydroperoxides are much preferred over peroxide. Inconsistent curing has been observed using peroxide. Mixtures of peroxides and hydroperoxides and mixtures of hydroperoxides are useful The catlytic agent component of the free radical initiator is preferably chemical in nature, preferably sulfur dioxide in gaseous form. Other chemical catalytic agents which are thought to have some practical utility includ amines and NO2 Once again it should be noted that a change of the catalytic agent can have a vivid influence upon -the rate of polymerization. However, other non-chemical agents which interact with the poxide components of the free radical initiator may also be of utility. For example, heat, an approximate minimum termperature of 140F' can interact with peroxide to form free radicals which serve to polymerize the Part I materials. Increasing the temperature tends to increase the polymerication and cause faster cure. The polymerization takes place without the presence of a chemical catalytic agent.
1 ~6883~
In preferred Eoundry pactice, the unsat~rated reactive polymer, monomer or mixtures thereof and the peroxide component of the free radical initiator are mixed with sand in a conventional manner. The sand mix is then formed into a desired foundry shape by ramming, blowing or other known foundry core and mold making methods. The shaped article is then exposed to the catalytic agent component of the free radical initiator. In the preferred method of this invention gaseous S02 is used as the catalytic agent of the free radical initiator. The gas is~present only in catalytic amounts as previousl stated. The exposure time of the sand mix to the gas can be as little as 1/2 second or less and the binder component cures on contact with the catalytic agent. When S02 is used as the catalytic agent in a foundry cold box process it is suspended in a stream of carrier gas in a known manner. The carrier gas is usuallY N2. As little as 0.5% S02 based upon the weight of the carrier gas is ade~uate to cause polymerization. It is also feasible to expose S02 to the binder component without the presence of any carrier gas.
Part I may also contain optional ingredients. For example additives for wetting and defoaming may be useful. Silanes have been found to be especially useful additives. Especially preferred are unsaturated silanes, for example vinyl silanes, Advantages of this binding composition as a foundry binder are the following. The collapsibility of the binder use for casting aluminum is excellent. It has been found that this binder i, 3L1~8~3~
i11 readily co11ap~e or shake out of an al~minum casti~g with the application of a minimum of external energy. The binder also provides good strength properties. The bench life of sand mixed with Part I is lengthy. The surface finish of castings made using this binder and process has been found to be very good. The pro-duction rate of cores and molds made using this binder system is rapid especially when SO2 gas is used as the catalytic agent.
A foundry utilizing the binder composition which is described herein will mix Part I and one component of the free radical initiator, preferably the peroxide, with sand or other suitable foundry aggregate in a known manner. The sand mix is then formed into the desired foundry shape, cor~s or molds, in known manner.
The sand mix is then exposed to the second component of the free radical initiator, preferably the catalytic agent which is preferably sulfur dioxide gas, and polymerization of the Part I
binding material immediately occurs to form the binder of this invention.
The present invention is further illustrated by the following examples in which, unless otherwise indicated, all parts are by weight and all percentages are weight percentages.
EXAMPLE I
Gel tests were oonducted on various unsaturated monomers and polymers to determine their tendency to polymerize and the speed of polymerization. In carrying out the tests from about 1.5 to 2 grams of unsaturated monomer or polymer (i.e. Part I) were mixed 1 ~6~83~
with 0.03 grams of t-butylhydroperoxide (the peroxide component of the free radical initiator). This mixture was then exposed to S2 gas (the catalytic agent of the free radical initiator) either by dispersing the gas in the liquid (bubbling) or by creating an S2 atmosphere above the liquid (contacting). The results, set forth below, indicate that all unsal:urated monomers and polymers polymerize. ThUS all the listed compounds are potential binders.
Those listed compounds which demonstrated rapid polymerization or gelling are of greatest potential foundry binders for use in foundry high speed cold box mold and core ma~ing rapid.
PART I FINDING OF POLYMERIZATION
Acrylic Acid Rapid, on contact with SO2 Ethyl Acrylate Slow, on contact with SO2 n-Butyl Acrylate Slow, on contact with SO2 Isobutyl Acrylate Slow, on contact with SO2
2-Ethylhexyl Acrylate Rapid, on contact with SO2 Isodecyl Acrylate Rapid, on contact with SO2 2-Ethoxyethyl Acrylate Rapid, on contact with SO2 Ethoxyethoxyethyl Acrylate Rapid, on contact with SO2 Butoxyethyl Acrylate Rapid, on contac~ with SO2 Hydroxyethyl Acrylate Rapid, on contact with SO2 Hydroxypropyl Acrylate Rapid, on contact with SO2 Glycidyl Acrylate Rapid, on contact with SO2 Dimethylaminoethyl Acrylate Rapid, on contact with SO2 Cyanoethyl Acrylate Rapid, on contact with SO2 Diacetone Acrylami.d Rapid, on contact with SO2 in Methanol, 50%
Acrylamid in Methanol, Rapid, on contact with SO~
50%
1 1~883 1 (N-Methylcarbamoyloxy)ethyl Acrylate Rapid, on contact with S02 Methylcellosol~e Acrylate Rapid, on contact with S02 Phenoxyethyl Acrylate Rapid, on contact with S02 Benzyl Acrylate Rapid, on contact with S0 Ethylene Glycol Acrylate Phthalate Rapid, on contact with S02 Melamine Acrylate Rapid, on contact with S02 Diethylene Glycol Diacrylate Rapid, on contact with S02 Hexanediol Diacrylate Rapid, on contact with S02 Butanediol Diacrylate Rapid, on contact with S02 Triethylene Glycol Diacrylate Rapid, on contact with S02 Tetraethylene Glycol Diacrylate Rapid, on contact with S02 Neopentyl Glycol Diacrylate Rapid, on contact with S02 1, 3-Butylene Glycol Diacrylate Rapid, on contact with S02 Trimethylolpropane Triacrylate Rapid, on contact with S02 Pentaerythritol Triacrylate Rapid, on contact with S02 Methacrylic Acid Rapid, on contact with S02 Methyl Methacrylate 510w, on bubbling with S02 2-Ethylhexyl Methacrylate Slow, on bubbling with S02 Hydroxypropyl Methacrylate Rapid, on contact with S02 Glycidyl Methacrylate Rapid, on contact with S02 Dimethylamino.ethyl Methacrylate Rapid, on contact with S02 ~thylene Glycol Dimethacrylate Rapid, on contact with S02 Trimethylolpropane Trimethacrylate Rapid, on contact with S02 Acrylated urethane derived from glycerine 65% in MIAK/HiSol-10 Rapid, on contact with S02 N-Methylol Acrylamid in water 60% Rapid, on contact with S02 N-[isobutoxymethyl] Acrylamid Rapid, on contact with S02 in Methanol 50%
Epocryl R-12 Resin (Shell) Slow, on contact with S2 Acrylated Epo~y 80% in Acetone UVITHAME 783 (Thiokol/Chem.Div.) ~apid. on contact with SO2 Acrylated Urethane Oligomer AROPOL *7200 (ASHLAND) un- Slow, on contact with SO2 saturated polyester restin in Acetone 60%
RICON 157 (Colorado Specialty Slow, on contact with SO2 Chemical) an unsaturated hydro-carbon resin in acetone 50%
Hydroxy PBG-2000 (Hystl Co.) an Slow, on contact with SO2 unsaturated hydrocarbon resin in aceton 50~
EXAMPLE II
An unsaturated polymer was prepared by reacting the equivalent of a 1 mole of pentane dio and the equivalent of 4 moles of hydroxy-ethyl acrylate with the equivalent of 3.0 moles of toluene diisocyanate. Dibutyltin dilaurate was used to catalyze the reaction. Based on the solds contents 0.14%
catalyst was used. Hydroquinone monoethyl either is used as an inhibitor. The reaction was carried out in a reaction medium (solvents) consisting of ethylhexyl acrylate and hydroxyethyl -acrylate. In carrying out the reaction a mixture of TDI and solvent is charged to a reaction vessel. Pentane diol is added to this mixture followed by the addition of hydroxyethyl acrylate. When the addition of hydroxyethyl acrylate is complete catalyst is added. The reaction is carried out under an air sparge. The reaction pLoceeded at 40 to 45C for 2.1 hours and then the temperature was raised to 80-85C and the reaction was continued 4.3 hours, then 0.03~ inhibitor is added and the reaction continued one-half hour. The product was allowed to cool. The product was test for nonvolatiles and 59.2% were found. This corresponded to a theoretical amount of nonvolatiles of 60%. The viscosity of the product was 6.0 stokes. 20 grams of the unsaturated polymer was then blended with 1.6 grams of acrylic acid, *Trade Marks /~
_ ,~_ :~ :3l68~
10.7 grams of diethylene glycol diacrylate, 9.9 grams of trimethylolpropane trimethacrylate and 2.0 grams of vinyls silane. Acrylic acid, diethylene glycol diacrylate and trimethylol propane triacrylate are unsaturated monomers. This solution of unsaturated polymer and unsaturated monomers is referred to as Part I. One gram of t-butylhydroperoxide, the peroxide component of the free radical initiator, was added to the solution of unsaturated polyme;r and unsaturated monomers.
Wedron 5010 sand (washed and dried fine grained silica sand, AFSGFN 66) was placed in a suitable mixing apparatus.
Part I and the peroxide component of the free radical initiator were admixed with the sand until a uniform distribution was achieved. The level of Part I plus peroxide is two per cent (2%) based upon weight of sand.
The sand mix was blown into a conventional core cavity or box for making standard tensile briquettes test cores known as "dog bones". The dog bone test cores were cured by exposing the cores to the catalytic component of the free radical initiator. The catalytic component is gaseous sulfur dioxide.
The cores were exposed to the SO2 catalyst for approximately 1/2 second (gas time) and the catalyst was removed by purging with nitrogen for 15 seconds and the core removed from the - .
box. Tensile strengths of the core in psi were 223 out of the box, and 205 after 3 hours and 227 after 24 hours.
- "Dog bone" cores similar to thos described above were used in shakeout studies with aluminum castings. Seven tensile ~. 18~83 1 briquettes (dog bones) were arranged in a mold. The mold incorporated a gating system. The mold is designed to provide hollow castings having a metal thickness of approximately one-quarter inch on all sides. An opening at an end of the casting is provided for removal of the core from the casting.
Molten aluminum at approximately 1300F prepared from aluminum ingots was poured into the mold. After cooling for about an hour the aluminum castings are broken from the gating system and removed from the mold for shake out testing.
Shakeout tests are performed by placing a casting in a one gallon container. The container is placed on an agitating mechanism and tumbled for 5 minutes. The weight of the sand core which is removed from the casting in this manner is compared to the initial weight of sand core and a percent shake-out is calculated. Sand remaining in the casting after the agitation described above is removed by scraping and also weighed. The sand core, bonded with the binder described above, was observed to have 100 shake-out. It should be noted that the shakeout test above described is not a standard test.
Applicants are not aware of any standard test to measure this quality. It is submitted that the test used is valid for gaining an understanding of the collapslbility of a binder and for comparing the relative collapsibility of binders. The percents given are subject to a degree of variance but are reliable indicators.
1 ~83~.
Sand Wedron 5010 at 74 to 78F
PART I
a~ unsaturated monomer acrylic acid 1.6 grams diethylene glycol diacrylate 10.7 grams tri-methylolpropane trimethacrylate 9.9 grams.
b) unsaturated polymer Synthesized as described below 20 grams.
unsaturated polymer ¦ synthesis ¦ i) polyisocyanate, in mole equivalent TDI 4 ii) polyol, in mole equivalent Glycerine - 1 iii) acrylate, in mole j equivalent hydroxyethyl acrylate, 5 iv) catalyst dibutyltin dilaurate 0-14~
v) inhibitor hydroquinone monomethyl ether ~ vii) solvent in % ethylhexyl acrylate and hydroxy-ethyl acrylate, 40%
viii) temp/time C/hr. 40 to 45 for 2.13 hrs. then 80 to 85 for 4~8 hrs.
ix) viscosity, stokes 16.0 ¦ x) % Nonvolatiles I actual 63.9 theoretical 60.0 I c) additive in grams vinyl silane - 2.0 ¦Free Radical InitiatorlPart II) a) peroxide component 2.2% t-butylhydroperoxide b) catalytic component SO2 gas Gas time, sec. 0.5 Purge time, sec. 15 with N2 Tensile Strength, psi out of box 178
Acrylamid in Methanol, Rapid, on contact with SO~
50%
1 1~883 1 (N-Methylcarbamoyloxy)ethyl Acrylate Rapid, on contact with S02 Methylcellosol~e Acrylate Rapid, on contact with S02 Phenoxyethyl Acrylate Rapid, on contact with S02 Benzyl Acrylate Rapid, on contact with S0 Ethylene Glycol Acrylate Phthalate Rapid, on contact with S02 Melamine Acrylate Rapid, on contact with S02 Diethylene Glycol Diacrylate Rapid, on contact with S02 Hexanediol Diacrylate Rapid, on contact with S02 Butanediol Diacrylate Rapid, on contact with S02 Triethylene Glycol Diacrylate Rapid, on contact with S02 Tetraethylene Glycol Diacrylate Rapid, on contact with S02 Neopentyl Glycol Diacrylate Rapid, on contact with S02 1, 3-Butylene Glycol Diacrylate Rapid, on contact with S02 Trimethylolpropane Triacrylate Rapid, on contact with S02 Pentaerythritol Triacrylate Rapid, on contact with S02 Methacrylic Acid Rapid, on contact with S02 Methyl Methacrylate 510w, on bubbling with S02 2-Ethylhexyl Methacrylate Slow, on bubbling with S02 Hydroxypropyl Methacrylate Rapid, on contact with S02 Glycidyl Methacrylate Rapid, on contact with S02 Dimethylamino.ethyl Methacrylate Rapid, on contact with S02 ~thylene Glycol Dimethacrylate Rapid, on contact with S02 Trimethylolpropane Trimethacrylate Rapid, on contact with S02 Acrylated urethane derived from glycerine 65% in MIAK/HiSol-10 Rapid, on contact with S02 N-Methylol Acrylamid in water 60% Rapid, on contact with S02 N-[isobutoxymethyl] Acrylamid Rapid, on contact with S02 in Methanol 50%
Epocryl R-12 Resin (Shell) Slow, on contact with S2 Acrylated Epo~y 80% in Acetone UVITHAME 783 (Thiokol/Chem.Div.) ~apid. on contact with SO2 Acrylated Urethane Oligomer AROPOL *7200 (ASHLAND) un- Slow, on contact with SO2 saturated polyester restin in Acetone 60%
RICON 157 (Colorado Specialty Slow, on contact with SO2 Chemical) an unsaturated hydro-carbon resin in acetone 50%
Hydroxy PBG-2000 (Hystl Co.) an Slow, on contact with SO2 unsaturated hydrocarbon resin in aceton 50~
EXAMPLE II
An unsaturated polymer was prepared by reacting the equivalent of a 1 mole of pentane dio and the equivalent of 4 moles of hydroxy-ethyl acrylate with the equivalent of 3.0 moles of toluene diisocyanate. Dibutyltin dilaurate was used to catalyze the reaction. Based on the solds contents 0.14%
catalyst was used. Hydroquinone monoethyl either is used as an inhibitor. The reaction was carried out in a reaction medium (solvents) consisting of ethylhexyl acrylate and hydroxyethyl -acrylate. In carrying out the reaction a mixture of TDI and solvent is charged to a reaction vessel. Pentane diol is added to this mixture followed by the addition of hydroxyethyl acrylate. When the addition of hydroxyethyl acrylate is complete catalyst is added. The reaction is carried out under an air sparge. The reaction pLoceeded at 40 to 45C for 2.1 hours and then the temperature was raised to 80-85C and the reaction was continued 4.3 hours, then 0.03~ inhibitor is added and the reaction continued one-half hour. The product was allowed to cool. The product was test for nonvolatiles and 59.2% were found. This corresponded to a theoretical amount of nonvolatiles of 60%. The viscosity of the product was 6.0 stokes. 20 grams of the unsaturated polymer was then blended with 1.6 grams of acrylic acid, *Trade Marks /~
_ ,~_ :~ :3l68~
10.7 grams of diethylene glycol diacrylate, 9.9 grams of trimethylolpropane trimethacrylate and 2.0 grams of vinyls silane. Acrylic acid, diethylene glycol diacrylate and trimethylol propane triacrylate are unsaturated monomers. This solution of unsaturated polymer and unsaturated monomers is referred to as Part I. One gram of t-butylhydroperoxide, the peroxide component of the free radical initiator, was added to the solution of unsaturated polyme;r and unsaturated monomers.
Wedron 5010 sand (washed and dried fine grained silica sand, AFSGFN 66) was placed in a suitable mixing apparatus.
Part I and the peroxide component of the free radical initiator were admixed with the sand until a uniform distribution was achieved. The level of Part I plus peroxide is two per cent (2%) based upon weight of sand.
The sand mix was blown into a conventional core cavity or box for making standard tensile briquettes test cores known as "dog bones". The dog bone test cores were cured by exposing the cores to the catalytic component of the free radical initiator. The catalytic component is gaseous sulfur dioxide.
The cores were exposed to the SO2 catalyst for approximately 1/2 second (gas time) and the catalyst was removed by purging with nitrogen for 15 seconds and the core removed from the - .
box. Tensile strengths of the core in psi were 223 out of the box, and 205 after 3 hours and 227 after 24 hours.
- "Dog bone" cores similar to thos described above were used in shakeout studies with aluminum castings. Seven tensile ~. 18~83 1 briquettes (dog bones) were arranged in a mold. The mold incorporated a gating system. The mold is designed to provide hollow castings having a metal thickness of approximately one-quarter inch on all sides. An opening at an end of the casting is provided for removal of the core from the casting.
Molten aluminum at approximately 1300F prepared from aluminum ingots was poured into the mold. After cooling for about an hour the aluminum castings are broken from the gating system and removed from the mold for shake out testing.
Shakeout tests are performed by placing a casting in a one gallon container. The container is placed on an agitating mechanism and tumbled for 5 minutes. The weight of the sand core which is removed from the casting in this manner is compared to the initial weight of sand core and a percent shake-out is calculated. Sand remaining in the casting after the agitation described above is removed by scraping and also weighed. The sand core, bonded with the binder described above, was observed to have 100 shake-out. It should be noted that the shakeout test above described is not a standard test.
Applicants are not aware of any standard test to measure this quality. It is submitted that the test used is valid for gaining an understanding of the collapslbility of a binder and for comparing the relative collapsibility of binders. The percents given are subject to a degree of variance but are reliable indicators.
1 ~83~.
Sand Wedron 5010 at 74 to 78F
PART I
a~ unsaturated monomer acrylic acid 1.6 grams diethylene glycol diacrylate 10.7 grams tri-methylolpropane trimethacrylate 9.9 grams.
b) unsaturated polymer Synthesized as described below 20 grams.
unsaturated polymer ¦ synthesis ¦ i) polyisocyanate, in mole equivalent TDI 4 ii) polyol, in mole equivalent Glycerine - 1 iii) acrylate, in mole j equivalent hydroxyethyl acrylate, 5 iv) catalyst dibutyltin dilaurate 0-14~
v) inhibitor hydroquinone monomethyl ether ~ vii) solvent in % ethylhexyl acrylate and hydroxy-ethyl acrylate, 40%
viii) temp/time C/hr. 40 to 45 for 2.13 hrs. then 80 to 85 for 4~8 hrs.
ix) viscosity, stokes 16.0 ¦ x) % Nonvolatiles I actual 63.9 theoretical 60.0 I c) additive in grams vinyl silane - 2.0 ¦Free Radical InitiatorlPart II) a) peroxide component 2.2% t-butylhydroperoxide b) catalytic component SO2 gas Gas time, sec. 0.5 Purge time, sec. 15 with N2 Tensile Strength, psi out of box 178
3 hr. 217 24 hr. 233 Binder level (Part I + peroxide 2 component) Metal Cast Aluminum Shakeout ~ 100 3 ~
Sand Wedron 5010 Wedron 5010 PART I
a) unsaturated Acrylic acid 1.6 ~ydroxyethyl acry-monomer diethylene glycol late 2.2 grams diacrylate 10.7 dicyclopentenyl grams trimethyl- acrylate 20.8 ~rams olpropane tri (N-Methylcarbamoy-acrylate 9.9 loxy) ethyl acry-grams late 17.3 g.
b) unsaturated Synthesized as polymer described below, 20 grams unsaturated polymer syn-thesis i) polyiso- TDI, 3 cyanate, in mole equiva-lent ii) polyol, in mole equivalent Olin 20-265a), 1 a)polyoxypropylene glycol iii) acrylate, in hydroxyethyl acry-mole equiva- late 4 lent iv) catalyst dibutyltin dilau- -rate, 0.14%
v) inhibitor hydroquinone mono-methyl ether vii) solvent in % ethylhexyl acrylate and hydroxyethyl acrylate, 40%
viii) temp/time C/ 40 to 45 for 2.1 thru hr 80 to 85 for 4.75 ix) viscosity 4.2 x) ~ Nonvolatiles actual 59.2 theoretical 60.0 c) additive in gram Vinyl silane 2.0 grams Free Radical Initiator (Part II) a) peroxide component 11.3% cumene hydro- 2.4% t-butylhydro-peroxide. peroxide b) catalytic SO2 gas S2 gas component Gas time, sec. 0.5 1 .
Purge time, sec. 15 with N2 15 with N2 .
Tensile Strength, psi our o~ box 160 3 hr 25 24 hr 48 hr 232 Binder level (Part I+
peroxide component) 2% 2 Metal Cast Aluminum Shakeout % 100 Sand Wedron 5010 Wedron 5010 PART I
a) unsaturated monomer Pentaerythritol acrylic acid 7.2g, triacrylate 40 diethylene glycol diacrylate 21.4g, trimethylolpropane triacrylate 13g.
b) unsaturated polymer synthesis i) polyisocyanate, in mole equivalent ii) polyol, in mole equivalent iii) acrylate, in mole equivalent iv) catalyst v) inhibitor vii) solvent in %
viii) temp/time C/hr.
ix) viscosity x) % Nonvolatiles actual theoretical c) additive in gram Free Radical Initiator (Part II) a) peroxide component 2.4% t-butylhydro- 2.4% t-butylhydroO
peroxide. peroxide b) catalytic component S02 gas S2 gas Gas time, sec. 0.5 Purge time, sec. 15 10 Tensile Strength, psi out of box 48 130 3 hr.
24 hr.
Binder lever (Part 1~ 2~ 2%
peroxide component) ~ ~8~3~
Sand Wedron 5010 Wedron 5010 a) unsaturated monoer Acrylic acid 3.2 g, diethylene glycol diacrylate 21.4 g, trimethylolpropane trimethacrylake 19.8g.
b) unsaturated polymer Synthesized as Same as Ex. 4. 40 desribed below grams 40 grams.
i) polyisocyanate in TDI~ 3 mole equivalent ii) polyol, in mole Olin 20-265, 1 equivalent iii) acrylate, in Hydroxyethyl mole equivalent acrylate, 4 iv) catalyst Dibutyltin dilaurate, 0.14%
v) inhibitor Hydroquinone mono methyl ether 0.07%
vii) solvent in % Pentoxone (93.7) hydroxyethyl acrylate 35~
viii) temp/time C/ 40 to 45 for 2 hrs.
hr. then 20 to 85 for 4 ix) viscosity Thixotropic after 3 days x) ~ Nonvolatiles actual 63.1 theoretical 65 c) additive in gram Vinyl Silane Vinyl Silane A-172 2.0 grams Acrylic Acid 1.6 grams.
Free Radical Initiator (Part II) a) peroxide component (90%~ t-butyl t-butyl peracetate hydroperoxide (6 grams~
2.2%
b) catalytic component SO2 gas Heat 450 for 90 sec.
Gas time, sec. 0.5 Purge time, sec. 15 with N2 Tensile Strength, psi out of box 53 75 3 hr. 93 24 hr.
Cold strength 155 160 Binder level (Part I+
peroxide component) 2% 2 a 16~3831 EXAMPLE lO 11 Sand Wedron 5010 Wedron 5010 PART I Same as Ex. lO
Acrylic acid 1.6 grams, trimethylol-a) unsaturated monomer propane ~riacrylate . 9 9g-b) unsaturated polymer Synthesized as described below, 20 grams.
unsaturated polymer synthesis i) polyisocyanate mole equivalent TDI, 3,5 ii) polyol, in mole glycerine di-equivalent ethylene glycol mixture (l:l),l iii) acrylate, in mole Hydroxyethyl equivalent acrylate 4.5 iv) ca~alyst dibutyltin dilaurate 0.14 v) inhibitor hydro~uinone monomethyl ether 0.07%
vii) solvent in % ethylhexyl acry-late ~ hydroxyethyl acrylate (4.6)40%
viii) temp/time C/hr. 40 to 45 for 2 hrs.
then 80 to 85 for
Sand Wedron 5010 Wedron 5010 PART I
a) unsaturated Acrylic acid 1.6 ~ydroxyethyl acry-monomer diethylene glycol late 2.2 grams diacrylate 10.7 dicyclopentenyl grams trimethyl- acrylate 20.8 ~rams olpropane tri (N-Methylcarbamoy-acrylate 9.9 loxy) ethyl acry-grams late 17.3 g.
b) unsaturated Synthesized as polymer described below, 20 grams unsaturated polymer syn-thesis i) polyiso- TDI, 3 cyanate, in mole equiva-lent ii) polyol, in mole equivalent Olin 20-265a), 1 a)polyoxypropylene glycol iii) acrylate, in hydroxyethyl acry-mole equiva- late 4 lent iv) catalyst dibutyltin dilau- -rate, 0.14%
v) inhibitor hydroquinone mono-methyl ether vii) solvent in % ethylhexyl acrylate and hydroxyethyl acrylate, 40%
viii) temp/time C/ 40 to 45 for 2.1 thru hr 80 to 85 for 4.75 ix) viscosity 4.2 x) ~ Nonvolatiles actual 59.2 theoretical 60.0 c) additive in gram Vinyl silane 2.0 grams Free Radical Initiator (Part II) a) peroxide component 11.3% cumene hydro- 2.4% t-butylhydro-peroxide. peroxide b) catalytic SO2 gas S2 gas component Gas time, sec. 0.5 1 .
Purge time, sec. 15 with N2 15 with N2 .
Tensile Strength, psi our o~ box 160 3 hr 25 24 hr 48 hr 232 Binder level (Part I+
peroxide component) 2% 2 Metal Cast Aluminum Shakeout % 100 Sand Wedron 5010 Wedron 5010 PART I
a) unsaturated monomer Pentaerythritol acrylic acid 7.2g, triacrylate 40 diethylene glycol diacrylate 21.4g, trimethylolpropane triacrylate 13g.
b) unsaturated polymer synthesis i) polyisocyanate, in mole equivalent ii) polyol, in mole equivalent iii) acrylate, in mole equivalent iv) catalyst v) inhibitor vii) solvent in %
viii) temp/time C/hr.
ix) viscosity x) % Nonvolatiles actual theoretical c) additive in gram Free Radical Initiator (Part II) a) peroxide component 2.4% t-butylhydro- 2.4% t-butylhydroO
peroxide. peroxide b) catalytic component S02 gas S2 gas Gas time, sec. 0.5 Purge time, sec. 15 10 Tensile Strength, psi out of box 48 130 3 hr.
24 hr.
Binder lever (Part 1~ 2~ 2%
peroxide component) ~ ~8~3~
Sand Wedron 5010 Wedron 5010 a) unsaturated monoer Acrylic acid 3.2 g, diethylene glycol diacrylate 21.4 g, trimethylolpropane trimethacrylake 19.8g.
b) unsaturated polymer Synthesized as Same as Ex. 4. 40 desribed below grams 40 grams.
i) polyisocyanate in TDI~ 3 mole equivalent ii) polyol, in mole Olin 20-265, 1 equivalent iii) acrylate, in Hydroxyethyl mole equivalent acrylate, 4 iv) catalyst Dibutyltin dilaurate, 0.14%
v) inhibitor Hydroquinone mono methyl ether 0.07%
vii) solvent in % Pentoxone (93.7) hydroxyethyl acrylate 35~
viii) temp/time C/ 40 to 45 for 2 hrs.
hr. then 20 to 85 for 4 ix) viscosity Thixotropic after 3 days x) ~ Nonvolatiles actual 63.1 theoretical 65 c) additive in gram Vinyl Silane Vinyl Silane A-172 2.0 grams Acrylic Acid 1.6 grams.
Free Radical Initiator (Part II) a) peroxide component (90%~ t-butyl t-butyl peracetate hydroperoxide (6 grams~
2.2%
b) catalytic component SO2 gas Heat 450 for 90 sec.
Gas time, sec. 0.5 Purge time, sec. 15 with N2 Tensile Strength, psi out of box 53 75 3 hr. 93 24 hr.
Cold strength 155 160 Binder level (Part I+
peroxide component) 2% 2 a 16~3831 EXAMPLE lO 11 Sand Wedron 5010 Wedron 5010 PART I Same as Ex. lO
Acrylic acid 1.6 grams, trimethylol-a) unsaturated monomer propane ~riacrylate . 9 9g-b) unsaturated polymer Synthesized as described below, 20 grams.
unsaturated polymer synthesis i) polyisocyanate mole equivalent TDI, 3,5 ii) polyol, in mole glycerine di-equivalent ethylene glycol mixture (l:l),l iii) acrylate, in mole Hydroxyethyl equivalent acrylate 4.5 iv) ca~alyst dibutyltin dilaurate 0.14 v) inhibitor hydro~uinone monomethyl ether 0.07%
vii) solvent in % ethylhexyl acry-late ~ hydroxyethyl acrylate (4.6)40%
viii) temp/time C/hr. 40 to 45 for 2 hrs.
then 80 to 85 for
4.8 hoursO
ix) viscosity lO stokes x) ~ Nonvolati~es actual 59.9 theoretical 60.0 c) additive in gram Vinyl silane A-172, 2 ~iSol lO
1007.
Free Radical Initiator(Part II) a) peroxide component 70~ t-butyl hydro-peroxide 2.2%
b) catalytic component S02 gas l/2% S02 gas in N2 carrie~ gas Gas time, sec. 0.5 1/2 Purge time, sec. 15 with N2 gas None Tensile Strength, psi out of box 228 70 3 hr. 227 122 24 hr. 257 223 Binder level (Part I +
peroxide component) 2% 1.5 Metal Cast Aluminum Shakeout % - 25 -3 ~6883~
Sand Wedron 5010 PART I
a) unsaturated monomer Acrylic acid 1.6g. diethylene ~lycol 5.49 trimethylol propane triacrylate 9.9 b) unsaturated polymer Synthesized as decribed below, 20 grams.
unsaturated polymer synthesis i) polyisocyanate mole equivalents 4 ii) polyol, in mole equivalents ylycerine 1 iii) acrylate, in mole hydroxyethyl equivalents acrylate iv) catalyst dibutyltin dilaurate 0.14 v) inhibitor hydroquinone monomethyl ether 0.03 vii) solvent in % methyl isoamyl ketone, HiSol 10 (65:35) 35%
viii) temp/time C/hr. 40 to 45 for 1.75 hours then 80 to 85 for 4.5 hours ix) viscosity, stokes 10 ' x) % Nonvolatiles actual 64.1 theortetical 65 c) additive in grams Vinyl silane 2.0 HiSol 10 5.3 Free Radical Initiator (Part II) a) peroxide component 2.2% t-butylhydroperoxide - 70 b) catalytic component 1% SO2 gas in N2 carrier gas Gas time, sec. 20 Purge time, sec. None Tensile Strength, psi out of box 218 3hr. 157 24 hr. 233 Binder level (Part I+
peroxide component) 1.5 ~etal Cast Aluminum Shakeout % 100 ~ ~883 ~ 13 EXAMPLE
Sand Wedron 5010 PART I
a) unsaturated monomer Acrylic acid 1.6g. diethylene glycol 5.49 trimethylol propane triacrylate 9.9 b) unsaturated polymer Synthesized as described below, 20 grams.
unsaturated polymer synthesis i) polyiscocyanate - mole equivalents 4 ii) polyol, in mole equivalents glycerine 1 iii) acrylate, in mole hydroxyethyl equivalents acrylate iv) catalyst dibutyltin dilaurate 0.14 v) inhibitor hydroquinone monomethyl ether 0.03 vii) solvent in ~ methyl isoamyl ketone, HiSol 10 (65:35) 35%
viii) temp/time C/hr 40 to 45 for 1.75 hours then 80 to 85 for 4.5 hours ix) viscosity, stokes 10 x) % Nonvolatiles actual 64.1 theoretical 65 c) additive in grams Vinyl silane 2.0 HiSol 10 5.3 Free Radical Initiator (Part II) a) peroxide component 2.2% t-butylhydroperoxide - 70 b) catalytic component SO2 gas Gas time, sec. 0.5 Purge time, sec. 15 with air Tensile Strength, psi out of box 177 3 hr. 95 24 hr. 150 Binder level ~Part I +
peroxide component) 1.5 Metal Cast Aluminum Shakeout % 100
ix) viscosity lO stokes x) ~ Nonvolati~es actual 59.9 theoretical 60.0 c) additive in gram Vinyl silane A-172, 2 ~iSol lO
1007.
Free Radical Initiator(Part II) a) peroxide component 70~ t-butyl hydro-peroxide 2.2%
b) catalytic component S02 gas l/2% S02 gas in N2 carrie~ gas Gas time, sec. 0.5 1/2 Purge time, sec. 15 with N2 gas None Tensile Strength, psi out of box 228 70 3 hr. 227 122 24 hr. 257 223 Binder level (Part I +
peroxide component) 2% 1.5 Metal Cast Aluminum Shakeout % - 25 -3 ~6883~
Sand Wedron 5010 PART I
a) unsaturated monomer Acrylic acid 1.6g. diethylene ~lycol 5.49 trimethylol propane triacrylate 9.9 b) unsaturated polymer Synthesized as decribed below, 20 grams.
unsaturated polymer synthesis i) polyisocyanate mole equivalents 4 ii) polyol, in mole equivalents ylycerine 1 iii) acrylate, in mole hydroxyethyl equivalents acrylate iv) catalyst dibutyltin dilaurate 0.14 v) inhibitor hydroquinone monomethyl ether 0.03 vii) solvent in % methyl isoamyl ketone, HiSol 10 (65:35) 35%
viii) temp/time C/hr. 40 to 45 for 1.75 hours then 80 to 85 for 4.5 hours ix) viscosity, stokes 10 ' x) % Nonvolatiles actual 64.1 theortetical 65 c) additive in grams Vinyl silane 2.0 HiSol 10 5.3 Free Radical Initiator (Part II) a) peroxide component 2.2% t-butylhydroperoxide - 70 b) catalytic component 1% SO2 gas in N2 carrier gas Gas time, sec. 20 Purge time, sec. None Tensile Strength, psi out of box 218 3hr. 157 24 hr. 233 Binder level (Part I+
peroxide component) 1.5 ~etal Cast Aluminum Shakeout % 100 ~ ~883 ~ 13 EXAMPLE
Sand Wedron 5010 PART I
a) unsaturated monomer Acrylic acid 1.6g. diethylene glycol 5.49 trimethylol propane triacrylate 9.9 b) unsaturated polymer Synthesized as described below, 20 grams.
unsaturated polymer synthesis i) polyiscocyanate - mole equivalents 4 ii) polyol, in mole equivalents glycerine 1 iii) acrylate, in mole hydroxyethyl equivalents acrylate iv) catalyst dibutyltin dilaurate 0.14 v) inhibitor hydroquinone monomethyl ether 0.03 vii) solvent in ~ methyl isoamyl ketone, HiSol 10 (65:35) 35%
viii) temp/time C/hr 40 to 45 for 1.75 hours then 80 to 85 for 4.5 hours ix) viscosity, stokes 10 x) % Nonvolatiles actual 64.1 theoretical 65 c) additive in grams Vinyl silane 2.0 HiSol 10 5.3 Free Radical Initiator (Part II) a) peroxide component 2.2% t-butylhydroperoxide - 70 b) catalytic component SO2 gas Gas time, sec. 0.5 Purge time, sec. 15 with air Tensile Strength, psi out of box 177 3 hr. 95 24 hr. 150 Binder level ~Part I +
peroxide component) 1.5 Metal Cast Aluminum Shakeout % 100
Claims (61)
1. A process for forming shaped foundry articles comprising:
a) distributing on a foundry aggregate a binding amount of a binder material, said binder material comprising an ethylenically unsaturated monomer;
b) shaping the aggregate into the desired foundry article, and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent comprises gaseous sulphur dioxide.
a) distributing on a foundry aggregate a binding amount of a binder material, said binder material comprising an ethylenically unsaturated monomer;
b) shaping the aggregate into the desired foundry article, and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent comprises gaseous sulphur dioxide.
2. The process of claim 1 wherein the aggregate is sand.
3. The process of claim 2 wherein the binder material comprises a mixture wherein at least one other ethylenically unsaturated monomer is blended with said monomer.
4. The process of claim 2 wherein the binder material comprises at least one ethylenically unsaturated polymer in addition to said monomer.
5. The process of claim 2 wherein the catalytic agent is suspended in a carrier gas and exposed to the binder material for at least 0.5 seconds.
6. The process of claim 2 wherein the amount of binder material is up to 10% based upon the weight of sand.
7. The process of claim 4 wherein the binder material is curable at room temperature in less than one second.
8. The process of claim 1 wherein the binder material is curable at room temperature in less than one second.
9. The process of claim 1 wherein said monomer is an acrylate.
10. The process of claim 9 wherein said acrylate is polyfunctional.
11. The process of claim 1 wherein said monomer is selected from the group of alkyl acrylates, hydroxyalkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, cyanoalkyl methacrylates, N-alkoxymethylacrylamides, N-alkoxymethylmethacrylamides, hexanediol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, methacrylic acid, 2-ethyl hexylmethacrylate, or mixtures thereof.
12. The process of claim 1 wherein the binder is in a non-anaerobic environment when contacted with said gaseous sulphur dioxide.
13. The process of claim 11 wherein said monomer is selected from the group of pentaerythritol triacrylate, trimethylolpropane triacrylate 1,6-hexanediol diacrylate, tetraethylene glycol diacrylate, and mixtures thereof.
14. The process of claim 11 wherein said monomer includes trimethylolpropane triacrylate.
15. A process for forming sahped foundry articles comprising:
a) distributing on a foundry aggregate a bonding amount of a binder material, said binder material comprising a reactive ethylenically unsaturated polymer, b) shaping the aggregate into the desired foundry article, and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent comprises gaseous sulphur dioxide.
a) distributing on a foundry aggregate a bonding amount of a binder material, said binder material comprising a reactive ethylenically unsaturated polymer, b) shaping the aggregate into the desired foundry article, and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent comprises gaseous sulphur dioxide.
16. The process of claim 15 wherein the aggregate is sand.
17. The process of claim 16 wherein the binder material comprises a mixture wherein the ethylenically unsaturated polymer is mixed with at least one other ethylenically unsaturated polymer.
18. The process of claim 16 wherein the unsaturated polymer is an oligomer.
19. The process of claim 16 wherein the unsaturated polymer is an adduct.
20. The processf of claim 15 wherein said polymer is selected from the group of epoxy acrylate reaction products, polyester/urethane/acrylate reaction products, polyether acrylate, polyester acrylates, or mixtures thereof.
21. A process for bonding at least two materials comprising:
a) distributing on at least one of said materials a binding amount of a binder material, said binder material comprising an ethylenically unsaturated monomer;
b) bringing the materials to be bonded into contact, and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a ]catalytic agent wherein said catalytic agent is gaseous sulphur dioxide.
a) distributing on at least one of said materials a binding amount of a binder material, said binder material comprising an ethylenically unsaturated monomer;
b) bringing the materials to be bonded into contact, and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a ]catalytic agent wherein said catalytic agent is gaseous sulphur dioxide.
22. The process of claim 21 wherein the binder material comprises a mixture wherein at least one other ethylenically unsaturated monomer is blended with said monomer.
23. The process of claim 21 wherein the binder material comprises at least one ethylenically unsaturated polymer in addition to said monomer.
24. The process of claim 21 wherein the catalytic agent is suspended in a carrier gas and exposed to the binder material for at least 0.5 seconds.
25. A process for bonding at least two materials comprising:
a) distributing on at least one of said materials a bonding amount of a binder material, said binder material comprising a reactive ethylenically unsaturated polymer;
b) bringing the materials to be bonded into contact;
and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent is gaseous sulphur dioxide.
a) distributing on at least one of said materials a bonding amount of a binder material, said binder material comprising a reactive ethylenically unsaturated polymer;
b) bringing the materials to be bonded into contact;
and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent is gaseous sulphur dioxide.
26. The process of claim 25 wherein the binder material comprises a mixture wherein the ethylenically unsaturated polymer is mixed with at least one other ethylenically unsaturated polymer.
27. The process of claim 25 wherein the unsaturated polymer is an oligomer.
28. The process of claim 25 wherein the unsaturated polymer is an adduct.
29. Process of casting metal articles, said metal articles being shaped by use of foundry art:icles, which foundry articles collapse after casting said metal articles comprising:
a) forming a shaped foundry article by distributing on a foundry aggregate a binding amount of a binder material selected from the group of an ethvlenically unsaturated monomer, reactive ethylenically unsaturated polymer, or mixtures thereof; shaping the aggregate into the desired foundry article, and polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent, wherein said catalytic agent comprises gaseous sulphur dioxide;
b) heating a metal until it melts and is castable;
c) casting said metal using the shaped foundry article;
d) allowing the case metal to solidify; and e) collapsing the foundry article and removing said collapsed foundry article from the cast metal article.
a) forming a shaped foundry article by distributing on a foundry aggregate a binding amount of a binder material selected from the group of an ethvlenically unsaturated monomer, reactive ethylenically unsaturated polymer, or mixtures thereof; shaping the aggregate into the desired foundry article, and polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent, wherein said catalytic agent comprises gaseous sulphur dioxide;
b) heating a metal until it melts and is castable;
c) casting said metal using the shaped foundry article;
d) allowing the case metal to solidify; and e) collapsing the foundry article and removing said collapsed foundry article from the cast metal article.
30. The process of claim 29 wherein said binder material comprises an ethylenically unsaturated monomer.
31. The process of claim 30 wherein the binder material comprises a mixture wherein at least one other ethylenically unsaturated monomer is blended with said monomer.
32. The process of claim 29 wherein the binder is in a non-anaerobic environment when contacted with said gaseous sulphur dioxide.
33. The process of claim 29 wherein said binder material comprises a reactive ethylenically unsaturated polymer.
34. The process of claim 33 wherein the binder material comprises a mixture wherein the ethylenically unsaturated polymer is mixed with at least one other ethylenically unsaturated polymer.
35. The process of claim 29 wherein said binder material comprises a mixture of said monomer and said polymer.
36. The process of claim 29 wherein said aggregate is sand.
37. The process of claim 29 wherein the catalytic agent is suspended in a carrier gas and exposed to the binder material for at least 0.5 seconds.
38. The process of claim 36 wherein the amount of binder material is up to 10% based upon the weight of sand.
39. The process of claim 29 wherein said metal is a lightweight metal.
40. The process of claim 39 wherein said binder material comprises an ethylenically unsaturated monomer.
41. The process of claim 40 wherein the binder material comprises a mixture wherein at least one other ethylenically unsaturated monomer is blended with said monomer.
42. The process of claim 39 wherein said binder material comprises a reactive ethylenically unsaturated polymer.
43. The process of claim 42 wherein the binder material comprises a mixture wherein the ethylenically unsaturated polymer is mixed with at least one other ethylenically unsaturated polymer.
44. The process of claim 39 wherein said binder material comprises a mixture of said monomer and said polymer.
45. The process of claim 44 wherein said metal is aluminum.
46. The process of claim 39 wherein said metal is aluminum.
47. The process of claim 45 wherein said aggregate is sand.
48. The process of claim 39 wherein said aggregate is sand.
49. The process of claim 39 wherein the catalytic agent is suspended in a carrier gas and exposed to the binder material for at least 0.5 seconds.
50. The process of claim 48 wherein the amount of binder material is up to 10% based upon the weight of sand.
51. A process for forming shaped foundry articles comprising:
a) distributing on a foundry aggregate a bonding amount of a binder material said binder material comprising an acrylated urethane polymer;
b) shaping the aggregate into the desired foundry article; and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent comprises gaseous sulphur dioxide.
a) distributing on a foundry aggregate a bonding amount of a binder material said binder material comprising an acrylated urethane polymer;
b) shaping the aggregate into the desired foundry article; and c) polymerizing the binder material by means of a free radical initiator, said initiator comprising an organic peroxide and a catalytic agent wherein said catalytic agent comprises gaseous sulphur dioxide.
52. The process of claim 51 wherein said binder material also includes a reactive ethylenically unsaturated monomer.
53. The process of claim 52 wherein said unsaturated monomer includes a polyfunctional acrylate.
54. The process of claim 52 wherein said unsaturated monomer includes a member selected from the group of pentaerythritol triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, tetraethylene glycol diacrylate, and mixtures thereof.
55. The process of claim 54 wherein said acrylated urethane is from reactants comprising toluene diisocyanate, a polyol, and hydroxyethyl acrylate.
56. The process of claim 55 wherein said polyol includes glycerine.
57. The process of claim 56 wherein said polyol also includes diethylene glycol.
58. The process of claim 57 wherein said monomer also includes acrylic acid.
59. The process of claim 58 wherein the binder is in a non-anaerobic environment when contacted with said gaseous sulphur dioxide.
60. The process of claim 51 wherein the binder is in a non-anaerobic environment when contacted with said gaseous sulphur dioxide.
61. The process of claim 51 wherein the aggregate is sand.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11002580A | 1980-01-07 | 1980-01-07 | |
| US110,025 | 1980-01-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1168831A true CA1168831A (en) | 1984-06-12 |
Family
ID=22330849
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000367602A Expired CA1168831A (en) | 1980-01-07 | 1980-12-29 | Process of forming foundry cores and molds utilizing binder curable by free radical polymerization |
Country Status (25)
| Country | Link |
|---|---|
| JP (2) | JPS5835780B2 (en) |
| KR (1) | KR840000672B1 (en) |
| AR (1) | AR227904A1 (en) |
| AT (1) | AT397359B (en) |
| AU (1) | AU526004B2 (en) |
| BE (1) | BE886988A (en) |
| BR (1) | BR8100066A (en) |
| CA (1) | CA1168831A (en) |
| CH (1) | CH660019A5 (en) |
| DE (1) | DE3100157C2 (en) |
| DK (1) | DK170553B1 (en) |
| ES (3) | ES498356A0 (en) |
| FR (1) | FR2472958A1 (en) |
| GB (1) | GB2066714B (en) |
| IE (1) | IE50414B1 (en) |
| IT (1) | IT1134962B (en) |
| MA (1) | MA19038A1 (en) |
| MX (1) | MX165134B (en) |
| NL (1) | NL185611C (en) |
| NO (1) | NO159349C (en) |
| PH (2) | PH19861A (en) |
| PT (1) | PT72317B (en) |
| SE (3) | SE448833B (en) |
| TR (1) | TR21901A (en) |
| ZA (1) | ZA8136B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4320218A (en) * | 1980-08-04 | 1982-03-16 | Ashland Oil, Inc. | Binder composition |
| DE3224402C2 (en) * | 1982-06-30 | 1987-02-12 | Hüttenes-Albertus Chemische Werke GmbH, 4000 Düsseldorf | Process for the production of foundry moulded parts, in particular for light metal casting |
| US4806576A (en) * | 1982-08-05 | 1989-02-21 | Ashland Oil, Inc. | Curable epoxy resin compositions and use in preparing formed, shaped, filled bodies |
| US4518723A (en) * | 1982-08-05 | 1985-05-21 | Cl Industries, Inc. | Curable epoxy resin compositions and use in preparing formed, shaped, filled bodies |
| US4516996A (en) * | 1983-04-07 | 1985-05-14 | Owens-Corning Fiberglas Corporation | Formation of molded glass fiber parts from glass fiber blankets and product |
| US4791022A (en) * | 1983-11-07 | 1988-12-13 | Owens-Corning Fiberglas Corporation | Decorative panels |
| US5880175A (en) * | 1997-03-04 | 1999-03-09 | Ashland Inc. | Amine cured foundry binder system and their uses |
| US6429236B1 (en) * | 2000-05-23 | 2002-08-06 | Ashland Inc. | Acrylic-modified phenolic-urethane foundry binders |
| US20050250873A1 (en) * | 2004-01-29 | 2005-11-10 | Fox Joseph R | Compositions and process for inhibiting the movement of free flowing particles |
| CN115921768B (en) * | 2022-12-08 | 2023-10-24 | 江苏华岗材料科技发展有限公司 | Cold box resin for casting and preparation method thereof |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3179990A (en) * | 1961-10-26 | 1965-04-27 | Freeman Chemical Corp | Foundry composition with cross-linked polyester binder |
| DE1220609B (en) * | 1962-07-30 | 1966-07-07 | Eastman Kodak Co | Process for polymerizing liquid, olefinically unsaturated monomers |
| US3367992A (en) * | 1964-06-05 | 1968-02-06 | Dow Chemical Co | 2-hydroxyalkyl acrylate and methacrylate dicarboxylic acid partial esters and the oxyalkylated derivatives thereof |
| CH463105A (en) * | 1965-02-24 | 1968-09-30 | Phoenix Gummiwerke Ag | Storable, dry and heat-curable, pressable mixture and process for its production |
| DE1608337B1 (en) * | 1968-03-01 | 1970-07-09 | Huettenes Kg Geb | binder |
| JPS5213499B2 (en) * | 1973-02-05 | 1977-04-14 | ||
| GB1419800A (en) * | 1973-04-14 | 1975-12-31 | Ciba Geigy Ag | Making shaped articles from particulate material and an anaerobic adhesive |
| JPS5145616A (en) * | 1974-10-18 | 1976-04-19 | Hitachi Metals Ltd | IMONOSUNA |
| GB1510645A (en) * | 1974-12-11 | 1978-05-10 | Ciba Geigy Ag | Making shaped articles from particulate material and an anaerobic adhesive |
| JPS53102989A (en) * | 1977-02-22 | 1978-09-07 | Denki Kagaku Kogyo Kk | Curable composition |
| JPS5510320A (en) * | 1978-07-06 | 1980-01-24 | Mitsubishi Electric Corp | Composition for casting mold |
-
1980
- 1980-12-18 SE SE8008958A patent/SE448833B/en not_active IP Right Cessation
- 1980-12-19 GB GB8040853A patent/GB2066714B/en not_active Expired
- 1980-12-21 KR KR1019800005056A patent/KR840000672B1/en active
- 1980-12-29 CA CA000367602A patent/CA1168831A/en not_active Expired
- 1980-12-30 AU AU65896/80A patent/AU526004B2/en not_active Expired
-
1981
- 1981-01-05 MX MX185457A patent/MX165134B/en unknown
- 1981-01-05 ZA ZA00810036A patent/ZA8136B/en unknown
- 1981-01-05 TR TR21901A patent/TR21901A/en unknown
- 1981-01-05 IE IE5/81A patent/IE50414B1/en not_active IP Right Cessation
- 1981-01-05 PH PH25050A patent/PH19861A/en unknown
- 1981-01-06 DK DK004181A patent/DK170553B1/en not_active IP Right Cessation
- 1981-01-06 MA MA19239A patent/MA19038A1/en unknown
- 1981-01-06 CH CH37/81A patent/CH660019A5/en not_active IP Right Cessation
- 1981-01-06 NL NLAANVRAGE8100026,A patent/NL185611C/en not_active IP Right Cessation
- 1981-01-06 NO NO810020A patent/NO159349C/en not_active IP Right Cessation
- 1981-01-06 PT PT72317A patent/PT72317B/en not_active IP Right Cessation
- 1981-01-07 ES ES498356A patent/ES498356A0/en active Granted
- 1981-01-07 AT AT0002281A patent/AT397359B/en not_active IP Right Cessation
- 1981-01-07 AR AR283884A patent/AR227904A1/en active
- 1981-01-07 BE BE0/203418A patent/BE886988A/en not_active IP Right Cessation
- 1981-01-07 DE DE3100157A patent/DE3100157C2/en not_active Expired
- 1981-01-07 IT IT19037/81A patent/IT1134962B/en active
- 1981-01-07 BR BR8100066A patent/BR8100066A/en unknown
- 1981-01-07 JP JP56000532A patent/JPS5835780B2/en not_active Expired
- 1981-01-07 FR FR8100167A patent/FR2472958A1/en active Granted
-
1982
- 1982-02-01 ES ES509237A patent/ES8301707A1/en not_active Expired
- 1982-02-01 ES ES509238A patent/ES8303144A1/en not_active Expired
-
1983
- 1983-03-19 JP JP58045341A patent/JPS58187233A/en active Granted
- 1983-08-23 PH PH29430A patent/PH22002A/en unknown
-
1986
- 1986-09-02 SE SE8603682A patent/SE459256B/en not_active IP Right Cessation
-
1987
- 1987-09-07 SE SE8703466A patent/SE459400B/en not_active IP Right Cessation
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