FR2472958A1 - PROCESS FOR - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS FOR FORMING FOUNDRY ARTICLES, IN PARTICULAR CORES AND MOLDS, WHICH CONSISTS OF DISTRIBUTING ON A FOUNDRY AGGREGATE A BONDING MATERIAL CONSTITUTED OF ONE OR SEVERAL MONOMERS OR POLYMERS AT LEAST PARTIALLY WITH PREYLENICITY AND VENEERING OR ACRYLIC, FORM THE AGGREGATE INTO THE DESIRED FOUNDRY ARTICLE AND POLYMERIZE THE BONDING MATERIAL WITH A RADICAL PRIMER CONSISTING OF A PEROXIDE AND A CATALYTIC AGENT AND WHICH IS PREFERABLY GAS SULFUR DIOXIDE; A METHOD FOR CASTING LIGHT METALS WITH FOUNDRY ARTICLES PREPARED ACCORDING TO THE PREVIOUS METHOD IS ALSO DESCRIBED.

Description

The present invention relates to

  yielded to form cores and foundry molds and to cast light metals. Many different types of bonding materials are used to prepare foundry cores and molds. The bonding material, when cured, provides the cores and molds with various desirable properties. Examples of such properties are erosion resistance, moisture resistance, and sagability or agitation removal. Also in the preparation of nuclei and

  molds, we are looking for a high production rate.

  Modern techniques for the preparation of cores and molds have begun with the use as unsaturated drying-oil-binding materials derived from natural products. Flaxseed oil is the most common of these drying oils. By exposure to smell the oil of

  flax and other unsaturated oils, undergo

  Oxidation-triggered merizations that form strongly crosslinked solid structures. The polymerization can be accelerated by heating or chemically. These bonding materials are called in the industry, core oils. To form a core or mold, the oil is mixed with sand and the mixture is shaped. Curing is accomplished by heating or aging the core or mold for a prolonged period. The. core-based oil binders, in addition to the oil may contain other components such as esters. deriving from a

  oil, unsaturated hydrocarbon resins and

  solvents. The preparation processes. foundry shapes such as molds and kernels using oils

  for cores have been known since sixty to sixty years.

  More rapid processes than

  The aforementioned ceded using a core oil appeared 25 to 30 years ago. These processes require hardening by heating the bonding material. These methods of hot manufacturing of stone boxes are based on a thermosetting of resinous compositions. From the chemical point of view, these thermosetting resins are

  phenol-formaldehyde resins, urea-formaldehyde resins

  hyde and furfuryl-formaldehyde alcohol resins.

  In addition to the use of heat to harden or polymerize these bonding materials, it is often incorporated

acids as catalysts.

  About ten years ago, fast processes for the preparation of cores and molds

  Foundry have appeared. In these processes, the hardening

  Binding material is produced by a process of urethane chemistry. The bonding material consists of two resinous components

  liquids. One of the components is a phenol-for-

  maldéhyde. The second component is a polymeric isocyanate.

  The phenolic resin and the isocyanate resin are mixed with the sand and the mixture can be used in a "cold box" or "no-cook" technique. In the cold box technique, the sand which is coated with both components is blown into a core box. As soon as the sand-based mixture has been blown into the core box, an amine is passed through.

  tertiary gas through the core box for

  instantly evoke a hardening or solidification of the binder. U.S. Patent No. 3,409,579 illustrates this technology. In the process of making the cores without cooking, the sand, the polyisocyanate, the phenolic resin and a catalyst are mixed simultaneously. The sand mixture is then cast in a core box or in a model. The mixture

  Sand-based remains fluid for a while.

  When this time has elapsed, the catalyst causes curing or polymerization and the core forms rapidly as the bonding components react to form a urethane binder. Binders without cooking are described in the US patent

of America NI 3,676,392.

  U.S. Patent No. 3,879,339 discloses another bonding composition and another method for forming a foundry binder. This patent discloses a cold boot gas curing process, i.e. at ordinary temperature, to form a resin binder containing a resin

  organic curable by acids and an oxidizing agent.

  This binder is hardened with gaseous sulfur dioxide. The combination of sulfur dioxide with the oxidizing agent forms sulfuric acid which hardens the acid curable organic resin. Sulfuric acid is formed in situ and reacts with the resin. This gives the

  hardening of the binding composition.

  None of the foundry binders described above has utility and diversity of application

  by making an irreplaceable universal foundry binder.

  Each of these binders has certain advantages and

some disadvantages.

  The subject of the invention is a novel binder corresponding to a chemistry which has never been used in foundries or in other fields of use of binders. In particular, the invention relates to a foundry binder for the cold box process with fast curing. The invention also relates to a binder for the useful cold box process

  for casting aluminum and other light metals.

  The invention relates to binders which are preferably hardened at room temperature and which are formed by mixing: (a) a composition or material

  linkage of ethylenically unsaturated monomers

  and ethylenically unsaturated polymers and mixtures of such unsaturated monomers, ethylenically unsaturated polymers and mixtures of such unsaturated monomers and polymers, and (b) a radical initiator consisting of a peroxide and a catalytic agent. In general, the invention relates to ordinary temperature-curable bonding compositions which can be polymerized by radical initiation and chain extension. These binding compositions are useful for adhering materials and in particular solid particles. In particular the invention relates to compositions which can bind sand or other aggregates to form molds or cores for casting metals, particularly aluminum and other light metals. Molds and cores made with these binders have better settling ability when used for casting light metals, i.e.

  cast metals at low temperatures. Hardening

  The binding material preferably is at room temperature and is carried out with an initiator.

  radical consisting of a peroxide and a catalytic agent

  lytic. In a preferred form, the catalytic agent is

  gaseous and curing is almost instantaneous. How-

  the choice of different catalytic agents

  change the mode and speed of hardening.

  In general, the invention relates to

  a foundry binder corresponding to a different chemistry

  of the one used to date for forming binders useful in the foundry industry. This binder can also be used in fields other than the foundry industry. The chemistry of this binder is to some extent analogous to that previously used in the field of coatings (see, for example, British Patent No. 1 055 242) and adhesives (see for example various patents issued to Loctite Corporation). An anaerobic curing foundry binder corresponding to similar chemistry is described in Canadian Patent No. 1,053,440. This binder hardens

  very slowly and hardening requires heating.

  In the invention, such a hardening is not carried out

  anaerobic, but on the contrary a rapid hardening,

  than instant, at the ordinary temperature with some

catalytic agents.

  It is well known that to make foundry shapes, that is to say, cores and molds, is applied to sand, or other granulate, a substance or chemical bonding agent, the sand is shaped to the desired shape and causing or curing the bleeding chemical or chemical agent to obtain a shaped binder. According to the invention, to obtain a binder, two parts are combined. Part I is a binding substance or composition which undergoes polymerization or crosslinking causing adhesion, cohesion or binding of sand or other granulate in the desired form. The second part (part II) is an agent that causes the polymerization and crosslinking of the part I. This agent is called here "initiator

  In the present description we mean by

  "crosslinking", the establishment of a chain that is observed when a polymer joins with another polymer or a monomer. The term "polymerization" embraces

  "crosslinking" but also applies to an extension

  chain in which only monomers are involved.

  Part I of the bonding system can be described as an unsaturated composition

  be crosslinked or polymerized by radical mechanism.

  The unsaturation is preferably terminal or lateral.

  However, internal unsaturation is acceptable and polymerization also occurs by combination with Part II. It is also possible, depending on the method of synthesis of the component of Part I that it has both terminal and / or lateral unsaturation and internal unsaturation. It seems to the applicant that the mechanism of the polymerization is practically

  completely radical type in the case of

  cross-linkable (i.e., one or more unsaturated polymers). When certain monomers are used in the binding composition, it is possible that some of the polymerization will occur in a

  non-radical mechanism. So in the present

  description, the polymerization is described as a poly-

  radical merification and it seems to the plaintiff that in almost all cases the polymerization is performed well according to such a mechanism. However, in certain circumstances, in addition to the radical mechanism,

  other mechanisms may intervene in the polymeric

  tion. For carrying out the curing, the radical initiator is Part II consisting of a peroxide and a catalytic agent. The Applicant has discovered that unsaturated reactive monomers and polymers and their mixtures (i.e.

  binding composition) as hardened binding

  instantaneously when choosing appropriately

  certain catalytic agents of the radical initiator.

  The unsaturation of the monomers and polymers is preferably ethylenic. For example, reactive polymers, which may also be described as oligomers or as adducts, preferably containing vinyl or acrylic unsaturations, are used as binding compositions which, by polymerization, form the hardened binder of the sand of the cores or foundry molds. The radical initiator (part II) is mixed with the reactive polymer or monomer (part I) and free radicals are produced which polymerize the binding composition in the form of the hardened binder. This combination of a peroxide and a catalytic agent, this agent can in addition to its chemical nature consist of a form of energy, is called

here "radical initiator".

  The radical initiator of the invention can be used to polymerize the materials of Part I in many ways. For example, the peroxide can be mixed with the material of Part I and uniformly applied to sand. After giving the desired shape to the sand, it is exposed to the action of

  the catalytic agent. If not, we can add the catalytic agent

  lytic to the material of Part I and use the mixture to coat the sand and then shape as it is

24729-58

  desire the coated sand. The shaped article can then be added to the peroxide component of

  the radical initiator and curing by polymerization.

  The material of Part I can also be divided into two portions. The catalytic agent can be added to one portion and the peroxide added to the second. By combining the two portions, after application of at least a portion to the material to be bonded, polymerization occurs. Depending on the nature of the catalytic agent, the apparatus and the application, the latter process may or may not be used. However, if the bonding material is used to adhere non-particulate materials, the latter process may be

  particularly useful. The choice of the various agents

  lytical effects has an important effect on the way in which the binding material can be polymerized and on the rate of hardening of this material. For example, the choice of the appropriate catalytic agent allows the user to instantly polymerize the bonding material at ordinary temperature or to retard polymerization for a time and complete it at elevated temperatures. The possibility of choosing the polymerization conditions of the binding composition

is very important.

  As previously described, the binding material constituting part I is a polymerizable unsaturated monomer or polymer or a mixture of one or more of these monomers and polymers. Examples of materials suitable as monomers for

  Part 1, a wide variety of mono acrylates

  functional, difunctional, trifunctional and tetra-

  functional. Examples of such models are

  alkyl acrylates, hydroxyl acrylates,

  alkyl acrylates, alkoxyalkyl acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxylalkyl methacrylates, d-alkylalkyl methacrylates,

  cyanoalkyl methacrylates, N-alkoxy-methylacryl-

  amides and N-alkoxymethylmethacrylamides. Among the difunctional monomeric acrylates, there is

  hexanediol diacrylate and tetraethylene diacrylate

  glycol. Other acrylates that can be used are trimethylolpropane triacrylate, methacrylic acid and 2-ethylhexyl methacrylate. It is preferred to use polyfunctional acrylates when the monomer is the only binding component of the bonding system. As previously indicated, when only monomers are used as binding materials, cross-linking can not occur. Also the polymerization can, in addition to a radical mechanism, be produced

by other mechanisms.

  Examples of reactive unsaturated polymers which have been found to be particularly useful for forming the foundry binder are epoxy / acrylate reaction products, polyester / urethane / acrylate reaction products, polyether acrylates and polyester acrylates. Among the unsaturated polymers useful in the composition of Part I are commercial materials such as UVITHANE 782 and 783, Thliokol acrylated urethane oligomers, CMD 1700, an acrylate ester of an acrylic polymer, and the like. CELRAD 3701, an acrylated epoxy resin, both compounds from Celanese. The reactive polymers can be formed in many ways. A preferred method for preparing

  the reactive polymers consists in forming a prepoly-

  isocyanate-terminated mother by reaction of a polyhydroxy compound or polyol with a diisocyanate. The prepolymer is then reacted with a hydroxyalkyl acrylate to form an oligomer. A second method which has proved advantageous is to react a compound of the polyisocyanate type,

  preferably a diisocyanate, with a hydroxyl acrylate

  alkyl. The reaction product is an "adduct" of these two materials. In addition, under

  appropriate, oligomers

mothers and additions.

  In addition to the reactive unsaturated polymer, a solvent, preferably of a reactive nature, may be incorporated as a component of the binding material and preferably this incorporation is carried out. Depending on the nature of the unsaturated bonding material,

  also use inert solvents. The pre-solvent

  is an unsaturated monomeric compound such as those

  As a result, the material of Part I may consist of a mixture of these unsaturated monomers and an unsaturated polymer previously proposed for use in Part I. The best results are obtained when using a solution of an unsaturated reactive polymer and an unsaturated monomeric solvent. This combination appears to lend itself more readily to copolymerization and crosslinking to form a bonding matrix causing the sand or other granulate to adhere to each other to form a core or

  foundry mold or to bind other materials.

  As indicated it is preferred to use in part I of the binding system, an unsaturated monomer

  as a solvent in addition to the unsaturated polymer. As pre-

  described above, these monomers comprise an unsaturation and are crosslinkable with the polymer in addition to the fact that

  they serve as a solvent for unsaturated polymers.

  Any of the unsaturated monomers (or combinations thereof) which have been described as useful materials of Part I may be used as solvents. It is recommended that the unsaturation be ethylenic and preferably vinyl or acrylic. Preferred examples of monomers useful as solvents are:

  unsaturated polymers, pentaerythritol triacrylate

  tol, trimethylolpropane triacrylate, hexanediol-1,6-diacrylate and tetraethylene glycol diacrylate, the amount of monomers of part I may be between 0 and 100% relative to the total weight of

this part.

  The reactive polymer constituting the material of Part I and the radical initiator can be used in the absence of any solvent, including unsaturated monomer, of the unsaturated polymer. The unsaturated monomer can also be used as the material of Part I with a radical initiator but without a reactive polymer to obtain a polymerized binder. Or

  neither of these two combinations are pre-

  ferred. As previously indicated, the preferred binding system constituting Part I is made of a reactive unsaturated polymer dissolved in a reactive diluent, preferably an unsaturated monomeric solvent and Part II

  consists of a radical initiator.

  The radical initiator consists of two components. The first component is preferably an organic peroxide. However we can use, with

  the polymerizable linkage material by radical mechanism

  calaire constituting Part I and composed of unsaturated polymers and monomers and mixtures thereof as previously described, any substance forming free radicals by exposure to the action of a catalytic agent. The peroxide concentrations may vary within wide limits depending to some extent on the caitlytic agent used. In general, however, 0.5 to 2% peroxide based on the weight of the binding material (Part I) produces a satisfactory bond under most conditions. We can mention as

  examples of preferred peroxides, tert-hydroperoxide

  butyl, cumene hydroperoxide and methyl peroxide

  ethyl ketone. It should be noted that among the peroxides hydroperoxides are particularly preferred. Hardening anomalies were observed when using peroxides. Peroxide mixtures can be used

  and hydroperoxides and hydroperoxide mixtures.

he

  The catalytic agent of the radical initiator

  The calaire is preferably of a chemical nature and the gaseous sulfur dioxide is preferred. Other catalytic agents

  which seem to have some practical use

  tick, are amines and nitrogen dioxide. It should also be noted that a change in catalytic agent may have

  a significant effect on the polymerization rate. This-

  during other non-chemical agents

  The action with the peroxide component of the radical initiator may also be useful. For example, heating to a minimum temperature of about 600 ° C can, by interaction with peroxide, form free radicals to polymerize the materials of Part I.

  The rise in temperature tends to increase the polymer

  and accelerate hardening. Polymerization

  is carried out in the absence of a chemical catalytic agent.

  According to the preferred foundry practice, the unsaturated polymer or monomer, or a mixture thereof, is conventionally mixed with the sand.

  and the peroxide component of the radical initiator.

  The sand mix is then shaped into the desired foundry shape by crushing, blowing or other known method of preparing foundry cores and molds. The shaped article is then exposed to the action

  of the catalytic agent of the free radical initiator.

  In the preferred method of the invention,

  gaseous sulfur dioxide as catalytic agent of the amorphous

  radical. As previously indicated, this gas is only present in catalytic amounts. The exposure time of the mixture to the action of the gas can be as low as 0.5 seconds or less and the bonding component cures with the catalytic agent. When using

  sulfur dioxide as a catalytic agent in a process

  a cold box die, it is suspended in a current of a gas carrier in a known manner. The carrier gas is generally nitrogen. Sulfur dioxide content as low as 0.5% by weight

  carrier gas is suitable for causing the polymerization.

  The bonding component can also be contacted with sulfur dioxide in the absence of any carrier gas. Part I may also contain

  optional ingredients. For example, wet additives

  lime and defoamers may be helpful. Silanes

  have proved to be particularly useful additives.

  Unsaturated silanes are particularly preferred.

for example vinylsilanes. -

  The advantages of this composition of

  binding as foundry binder are as follows. The apti-

  The sagging of the binder used to cast aluminum is excellent. It has been found that this binder sinks easily or is removed by stirring an aluminum casting when a minimal external energy is applied. The binder also has good strength properties. The duration of use of the sand mixed with Part I is important. The surface finish of castings made with this binder and according to the methods of the invention is very good. The rate of production of cores and moultes made with this linkage system is high especially when

  uses gaseous sulfur dioxide as a catalytic agent.

  In the foundry for using the binding composition of the invention, part I and a component of the radical initiator, preferably the peroxide, are mixed in a known manner with sand or other granulate suitable for casting. It is then shaped in a known manner

  the sand-based mixture of cores or foundry molds.

  The sand-based mixture is then exposed to the action

  of the second component of the radical initiator, preferably

  Preferably the catalytic agent, which is preferably gaseous sulfur dioxide, and the polymerization of the connecting material constituting Part I occurs immediately and the desired cured binder is obtained. The invention is illustrated by the following nonlimiting examples. in which, unless otherwise indicated, parts and percentages are by weight.

EXAMPLE I

  Gelification tests are carried out

  with various unsaturated monomers and polymers to determine

  Their tendency to polymerize and the rate of polymerization. To carry out the tests, about 1.5 to 2 g of the unsaturated monomer or polymer (part I) are mixed with 0.03 g of tert-butyl hydroperoxide (component of the peroxide type of the radical initiator). This mixture is then exposed to the action of gaseous sulfur dioxide (catalytic agent of the radical initiator) either by dispersing the gas in the liquid (bubbling) or by creating a sulfur dioxide atmosphere above the liquid (contact ). The results below show that all unsaturated monomers and polymers

  polymerize. So all the compounds indicated constitute

  kill potential binders. The indicated compounds which exhibit rapid polymerization or gelling are particularly likely to be used as foundry binders for the rapid manufacture of molds

  and cores according to the cold box technique.

PART I POLYMERIZATION

  Acrylic acid Fast, by contact with SO2 Slow ethyl acrylate, by contact with SO 2 Slow butyl acrylate, by contact with SO 2 Slow isobutyl acrylate, by contact with SO 2 Fast 2-ethylhexyl acrylate, by contact with SQ 2 Isodecyl Acrylate Fast, by contact with SO2 2-Ethoxy-2-Ethyl Acrylate Rapid, by contact with SO2

Ethoxyethoxy acrylate

  Ethyl Fast, by contact with SO2 Acrylate of butoxyethyl Rapid, by contact with SO2 Hydroxyethyl acrylate Hydroxypropyl acrylate Glycidyl acrylate

Dimethyl acrylate

  aminoethyl Cyanoethyl acrylate Diacetone-acrylamide 50% 1 in methanol Acrylamide 50% in methanol

N-methyl acrylate

carbamoyloxyethyl

Methyl acrylate

cellosolve

Phenoxy acrylate

ethyl benzyl acrylate

Acrylate phthalate

tylene glycol melamine acrylate

Diethyl diacrylate

  eneGlycol Hexanediol diacrylate Butanediol diacrylate

Triethylene diacrylate

glycol

Tetracyclean diacrylate

ethylene glycol

Neopentyl diacrylate

glycol

Butanediol diacrylate

1.3

Trimethyl triacrylate

olpropane

Penta triacrylate

  Erythritol Methacrylic acid Methyl methacrylate Fast, Fast, Fast, Fast, Fast, through contact Contact contact Contact with SO 2 with SO 2 with SO 2 with SO 2 with SO 2 Rapid, by contact with SO 2 Rapid, by contact with SO 2 Fast, by contact with S02 Rapid, by contact with S02 Fast, Fast, Fast, Fast, Fast, Fast, Fast, by by by by by contact contact contact contact contact contact with with SO2 SO2 with SO2 with SO2 with with with Fast , by contact with SO2 Rapid, by contact with SO2 Rapid, by contact with SO2 Rapid, by contact with SO2 Fast, by Rapid, Rapid, by contact with SO2 contact contact with SO2 with SO2 Slow, by bubbling SO2 SO2 SO2 SO2 Slow ethyl 2-hexyl methacrylate, by bubbling S02

Hydroxy methacrylate

  propyl Fast, by contact with S02 Fast glycidyl methacrylate, by contact with S02

Dimethyl methacrylate

  aminoethyl Fast, by contact with S02

Ethyl dimethylacrylate

  Fast glycol, by contact with S02 Fast Trimethylolpropane trimethacrylate, by contact with S02

Acrylated urethane

  65% glycerine in a mixture of methylisopentylketone / HiSol10 Rapide, by contact with SO 2 N-methylolacrylamide in% Fast water, by contact with S02.

N-isobutoxyméthylacryl-

  50% amide in methanol Rapid, by contact with SO2 Epocryl R-12 Resin (Shell), Epoxy

80% acrylate in acetylene

  Slow tone, by contact with SO2 UVITHANE 783 (Thiokol / Chemo Div.), Fast acrylated urethane oligomer, by contact with SO2

AROPOL 7200 (ASHLAND)

unsaturated polyester sine

  at 60% in slow acetone, by contact with SO2 RICON 157 (Colorado

Specialty Chemical),

hydrocarbon sine

  50% saturated in slow acetone, by contact with SO2 Hydroxy PBG-2000 (Hystl Coo), 50% unsaturated hydrocarbon resin in slow acetone, by contact with SO2

EXAMPLE II

  An unsaturated polymer is prepared by reacting the equivalent of one mole of pentanediol and the equivalent of 4 moles of hydroxyethyl acrylate

  with the equivalent of 3.0 moles of diisocyanato

  toluene (TDI). Dibutyltin dilaurate is used to catalyze the reaction. 0.14% of catalyst is used relative to the content of the solids. We use

  the monoethyl ether of hydroquinone as an inhibitor.

  The reaction is carried out in a reaction medium (solvents)

  consisting of ethylhexyl acrylate and hydroxyalkyl acrylate

  ethyl. To carry out the reaction, a mixture of TDI and solvent is introduced into a reactor. Pentanediol is added to the mixture and then the acrylate is added

  hydroxyethyl. When the addition of the hydroxy acrylate

  ethyl is complete, the catalyst is added. The reaction is carried out with air diffusion. The reaction is continued between 40 and 450 ° C. for 2.5 hours, then the temperature is raised to 80 ° -85 ° C. and the reaction is continued for

  4.3 hours then 0.03% inhibitor is added and

  follow the reaction for half an hour. The product is allowed to cool. The nonvolatile material content of the product is determined to be 59.2%. This value

  corresponds to the theoretical quantity of non-volatile

  60% tiles. The viscosity of the product is 6.0 stokes.

  20 g of the unsaturated polymer are then mixed with 1.6 g

  of acrylic acid, 10.7 g of diethylene diacrylate

  glycol, 9.9 g of trimethylolpropane trimethacrylate and 2.0 g of vinylsilaneo Acrylic acid, diacrylate

  of diethylene glycol and trimethylol triacrylate

  propane are unsaturated monomers. This solution of unsaturated polymer and unsaturated monomers is called part I. The unsaturated polymer is added to the solution.

  and unsaturated monomers, 1 g of tert-hydroperoxide

  butyl which is the peroxide component of the radical initiator. Wedron sand 5010 (washed and dried fine grain silica sand, AFSGFN 66) is placed in a suitable mixer. We mix with sand the part

  I and the peroxide component of the radical initiator

  until it is evenly distributed.

  The content of the sum of Part I and peroxide

  is 2% based on the weight of the sand.

  The sand-based mixture is blown into a conventional core cavity or box to form standard, thick-end tensile specimens. The test pieces are cured by exposure to

  catalytic component of the radical initiator. Com-

  Catalytic posing is gaseous sulfur dioxide. The specimens are exposed to the action of sulfur dioxide for about 0.5 seconds (gas contact time), and the catalyst is purged by nitrogen purging for 15 seconds and the specimens are demolded. The tensile strengths of the specimens expressed in N / cm are 154 at the exit of the box, 141 after

3 hours and 157 after 24 hours.

Thick-end specimens similar to those previously described as cores were used in stirring elimination studies with aluminum castings. Seven of these tensile test pieces are available in a mold. The mold has a casting system. The mold is designed to form hollow castings having a metal thickness of about 6.4 mm on all sides. An opening at the end of the castings eliminates the core. Melted aluminum is poured into the mold

  at about 7040C prepared from an aluminum ingot.

  After cooling for about 1 hour, the aluminum castings are separated from the casting system and removed from the mold to perform the elimination test.

by agitation.

  To perform the elimination test

  by stirring, a casting is placed in a recess

  about 4 liters. This vessel is placed on a stirring mechanism and stirred for 5 minutes. The weight of the sand core thus removed from the casting is compared with the initial weight of the sand core and the percentage of removal by stirring is calculated. The sand remaining in the casting after scratching is scraped off and weighed. It is observed that the sand core bonded with the binder previously described has a stirring removal of 100. It should be noted that the agitation test just described is not a standard test. The Applicant does not know of a standard test for measuring this property. This test appears to be useful for assessing fitness

  sagging of a binder and to compare the

  studies relating to the settlement of binders. The percentages

  indicated are likely to vary but

  are reliable indications.

Of course various modifications

  may be made by those skilled in the art to the provisions

  methods or processes which have just been described as non-limiting examples without departing from the scope

of the invention.

Example

Sand

PART I

  a) unsaturated monomer b) unsaturated polymer

III IV

Wedron 5010 at 23.3-25.5 C

Acrylic acid 1.6 g, di-

diethylene acrylate

glycol 10.7 g, trimethacrylate

  9.9 g trimethylolpropane was synthesized as described below, 20 g Wedron 5010

Acrylic acid 1.6 g, di-

diethylene acrylate

glycol 10.7 g, triacrylated

  Trimethylolpropane slurry 9.9 g Synthesized as described below, 20 g V Wedron 5010 Hydroxyethyl acrylate

2.2 g, di-acrylate

cyclopentenyl 20.8 g,

N-methylcarbonate acrylate

  bamoyloxyethyl 17.3 g Synthesis of the unsaturated polymer: 1) polyisocyanate, in equit TDI, 4 molar valents 2) polyol, in molar equivalents

3) acrylate, in equivalence

  slow molar 4) catalyst) Glycerin inhibitor, 1

Hydroxy acrylate

ethyl, 5

Dibutyl dilaurate

  tin, 0.14% hydroquinone monomethyl ether

TDI, 3

Olin 20-265a) 1; a) poly-

  oxypropylene glycol Hydroxyethyl acrylate, 4 dibutyltin dilaurate, 0.14% Hydroquinone monomethyl ether Example 1 (continued 1) 7) solvent,% 8) temperature / time, C / h 9) viscosity, stokes) nonvolatile matter (%) - observed - theoretical c) additive, g Radical primer

PART II

  a) peroxide component b) catalytic component Gas contact time, s Purge time, s Tensile strength, N / Cm2 - at the outlet of the box -3h -24 h -48 h III Acrylate ethylhexyl and hydroxyethyl acrylate,% at 45 for 2; 13 h, then 80 at 85 for 4.8 h 16.0 63.9, 0 Vinylsilane, 2.0

Tert-hydroperoxide

  butyl, 2.2% 802 gaseous 0.5 with N2 IV Ethylhexyl acrylate and hydroxyethyl acrylate, 407% at 45 for 2.1 h, then 80 to 85 for 4.75 h 4, 2 59.2 600o Vinylsilane, 2.0 g Cumene hydroperoxide, 11.3% 802 gaseous 0.5 with N2 V

Tert-hydroperoxide

  butyl, 2.4% SO2 gaseous with N to ON)

III IV '

  Binder content (Part I + peroxide component) HMetal cast Agitation by stirring,% 2% Aluminum V 2% Aluminum "o FJi Yla Ln Co Example (continued 2) Example (continued 3) VI Sand

PART I

8a) Wedron 5010 unsaturated monomer

Penta triacrylate

  erythritol, 40 g b) unsaturated polymer Synthesis of the unsaturated polymer: 1) polyisocyanate, in molar equivalents

2) polyol, in equivalence

slow molars

3) acrylate, in equivalence

slow molar 4) catalyst

VII VIII

  Wedron 5010 Wedron 5010 Acrylic Acid 7.2g,

Diacrylate di

ethylene glycol 21.4g,

trimer triacrylate

  Thylolpropane 13 g Synthesized as described below, Port Crescent IX Acrylic Acid 3.2 g

diethyl diacrylate

ethylene glycol 21.4 g, tris

trimer methacrylate

  Thylolpropane 19.8 g As in Example IV, g

TDI, 3

Olin 20-265, 1

Hydroxy acrylate

ethyl, 4

Dibutyl dilaurate

  tin, 0.14%) monomethyl ether inhibitor

hydropower

  quinone ,, 0.07% r-J -4 ru ul o tJ Example (continued 4)

VI VII VIII

  7) solvent, in% 8) temperature / time C / h Pentoxone (93.7),

hydroxy acrylate

  ethyl, 35% to 45 for 2 hours, then 20 to 85 for 4 hours Thixotropic after 3 days 9) viscosity, stokes) non-volatile matter,% -observed theoretical c) additive, g 63.1 Vinylsilane A-172,

2.0 g; acrylic acid

  1.6 g Vinylsilane Radical Primer

PART II

a) peroxide component

(b) Catalyst component

  lytic Gas contact time, s Purge time, s Tert-butyl hydroperoxide, .2.4% SO2 gas 0.5 Tert-butyl hydroperoxide, 2.4% SO2 gas Tert-butyl hydroperoxide (90% ), 2.2% SO2 gaseous tert-butyl peracetate (6 g) Heating at 450 for 90 s 0.5 with N2 IX (n) Ca) Example (continued 5) VI VII VIII IX Tensile strength, N / cm2 - the output of the 33 90 37 52 boot -3 h 64 - 24 h - cold resistance 107 110 Binder content (Part I + 2% 2% 2% 2% peroxide component) Cast metal Elimination by stirring,%> 7 J- 'Ln co Example (continued 6) X Sand

PART I

  a) unsaturated monomer b) unsaturated polymer Wddron 5010 Acrylic acid 1, 6g,

tris triacrylate

  methylolpropane 9.9 g Wedron 5010 As in

example X

  Synthesized as described below, Wedron G 5010 Acrylic Acid 1.6g, Diethylene Glycol, 49g, Triacrylate

trimethylolpro-

  9.9 g Synthesized as described below, Wedron 5010 Acrylic Acid 1.6 g, Diethylene Glycol, 49 g, Trimethylolpropane triacrylate 9.9 g Synthesized as described below, Synthesis of unsaturated polymer: 1) Polyisocyanate , in molar equivalents

2) polyol, in equivalence

slow molars

3) acrylate, in equi-

  molar valents 4) catalyst) inhibitor

TDI, 3.5

Glycerin, 1

Hydroxy acrylate

Ethyl Mixture (1/1) of

glycerin and di-

Ethylene glycol, 1

Hydroxy acrylate

ethyl, 4.5

Dilaurate di

butyltin, 0.14%

Monomethyl ether

hydropower

quinone, 0.07%> l Glycerin, 1

Hydroxy acrylate

ethyl

  Dibutyl dibutyl dilaurate

  Tin, 0.14% / tin, 0.14% Monomethyl ether of hydroquinone, 0.03% Monomethyl ether of hydroquinone, 0.03% 1j ol IIi xi XII XIII Example (cont'd 7) X * 7) solvent,% 8) temperature / time, C / h 9) viscosity, stokes

) non-volatile

  tiles (%) - observed - theoretical c) additive, g

Ethyl acrylate

  hexyl + hydroxyethyl acrylate (4/6),% 7. at 45 for 2h,

then 80 to 85

  4.8 h 59.9, 0 vinylsilane A-172, 2, HiSol 10, 10.7 methyl isopentyl ketone, methyl isopentyl ketone, HiSol 10 (65/35), 35% HiSol 10 (65/35), 35 percent to 450 percent. 1.75 h and 80 to 85 for 4.5 h. 64.1 Vinylsilane, 2.0, HiSol 10, 5.3 to 45 for 1.75 h and then 80 to 85 for 4.5 h. 64.1 Vinylsilane 2, 0, HiSol 10, 5.3 Ca r ', Radical Primer

PART II

a) peroxide component

(b) Catalytic component

  gas contact time, s Purge time ,,, tert-butyl hydroperoxide (70%), 2.2% SO2 gas 0.5 with N2 gas 0.5% SO2 gas in N2 as gas carrier 0.5 nil tert-butyl hydroperoxide (2.2%), 7CF /. SO2 gas at 1% in

N2 as a carrier gas

  nil tert-butyl hydroperoxide (2.2%),% SO2 gaseous 0.5 with air II, - nu D "M M x x XII XIII Example (cont'd 8) X

Resistance to trac-

  tion, N / cm2 !! - at the exit of the boot -3h - 24 h Binder content (Part I + peroxide component) Cast metal

Elimination by agri-

  tation,% 156,5 2% Aluminum 1,5% 1,5 Aluminum 1,5 Aluminum - rIN in CO xi XII XIII

Claims (32)

  A process for forming shaped articles of foundry, characterized in that it consists in: a) distributing, on a foundry aggregate, a binder quantity of a binding material, which binder material consists of a monomer ethylenically unsaturated; b) shaping the granulate into the desired foundry article, and c) polymerizing the binding material with a radical initiator, said initiator being a peroxide   organic and a catalytic agent.   2. Method according to claim 1,   characterized in that the granulate is sand.   3. Method according to claim 2, characterized in that the bonding material consists of a mixture in which at least one other monomer to   Ethylenic unsaturation is mixed with said monomer.   4. Method according to claim 2, characterized in that the catalytic agent is of a chemical nature. 5. Method according to claim 4, characterized in that the catalytic agent is dioxide sulfur gas.   6. Process according to claim 2, characterized in that the binding material consists of at least one ethylenically unsaturated polymer in plus said monomer.   7. Method according to claim 5,   characterized in that the catalytic agent is in addition   pension in a carrier gas and is put in contact with   the bonding material for at least 0.5 seconds.   8. Process according to claim 5, characterized in that the catalytic agent is a   high temperature of at least about 52 C.   9. Process according to claim 5, characterized in that the quantity of binding material   is at most 10% o relative to the weight of the sand.   Process for forming shaped articles of foundry characterized in that it consists in: 1) distributing on a foundry aggregate a binder quantity of a bonding material, this bonding material consisting of an ethylenically unsaturated polymer . 2) shaping the granulate into the desired foundry article and 3) polymerizing the binding material with a radical initiator, this initiator being a peroxide   organic and a catalytic agent.   11. The method of claim 10,   characterized in that the granulate is sand.   12. Process according to claim 11, characterized in that the binding composition consists of a mixture in which the monomer & ethylenic unsaturation is mixed with at least one   another polymer with ethylenic unsaturation.   13. Process according to claim 11, characterized in that the catalytic agent is of a nature chemical.   14. Process according to Claim 11, characterized in that the catalytic agent is dioxide sulfur gas.   15. The method of claim 11,   characterized in that the catalytic agent is a temperature   high level of at least about 52 C.   16. The method of claim 11,   characterized in that the unsaturated polymer is an oligomer   mother. 17. Process according to claim 11, characterized in that the unsaturated polymer is a adduct.   18. Process for binding at least two materials, characterized in that it consists in: a) distributing on at least one of these materials a binder quantity of a release material, this bonding material consisting of an unsaturated monomer; ethylenically; b) contacting the materials to be bonded and c) polymerizing the binding material with a radical initiator, the initiator being a peroxide   organic and a catalytic agent.   19. The method of claim 18, characterized in that the bonding material consists of a mixture in which at least one other monomer to   Ethylenic unsaturation is mixed with said monomer.   20. The method of claim 18, characterized in that the catalytic agent is of a chemical nature. 21. Process according to claim 20, characterized in that the catalytic agent is dioxide sulfur gas.   22. Process according to claim 18, characterized in that the bonding material consists of at least one ethylenically unsaturated polymer in addition said monomer.   23. The method of claim 20,   characterized in that the catalytic agent is in addition   pension in a carrier gas and is put in contact with   the bonding material for at least 0.5 seconds.   24. The method of claim 18,   characterized in that the catalytic agent is a temperature   high level of at least about 520C.   25. Process for binding at least two materials, characterized in that it consists in: 1) distributing on a material at least one binder quantity of a binding material, this binding material consisting of an unsaturated polymer ethylenic, 2) put the materials to be united in contact; and 3) polymerizing the binding material with a radical initiator, the initiator being a peroxide   organic and a catalytic agent.   26. Process according to claim 25, characterized in that the binding composition consists of a mixture in which the ethylenically unsaturated monomer is mixed with at least one   another polymer with ethylenic unsaturation.   27. The method of claim 25, characterized in that the catalytic agent is of a chemical nature. 28. Process according to claim 27, characterized in that the catalytic agent is dioxide sulfur gas.   29. The method of claim 25,   characterized in that the catalytic agent is a temperature   high level of at least about 520C.   30. The method of claim 25,   characterized in that the unsaturated polymer is an oligomer mother.   31. The method of claim 25, characterized   in that the unsaturated polymer is an adduct.   32. A method for casting lightweight metal articles, said metal articles being shaped by using foundry articles that collapse after casting of the metal articles, characterized in that it comprises: a) forming an article shaped foundry as described   in any of claims 1,3,6,10 and 12;   b) heating a light metal until it melts and can be cast; c) casting this light metal using the shaped foundry article; d) allow the cast metal to solidify; and e) collapse the foundry article and eliminate the article   smelted foundry of light metal cast article.