Radical polymerization

(42) Date of commencement of the patent: 15. 8.1993 (45) Date of issue: 25. 3.1994 (30) Priority:

(73) Patent owner:

7th 1.1980 US 110025 claims.

(56) Documents:

AT-PS 167883 DE-AS1608337 DE-AS2203411 DE-OS157O452 DE-0S2417939 DE-0S2842114 DE-OS2908198 US-PS3879339

ASHLAND OIL, INC. 41101 ASHLAND (US).

(54) METHOD OF MANUFACTURING FOUNDRY FORMS AND CORE (57) A method of making foundry molds and cores, by mixing a binder material with a foundry molding material, Shaping the mixture and hardening the binder material, by distributing a binder material on the foundry mold material, containing an ethylenically unsaturated monomer and / or polymer, brings the foundry mold material into the desired shape and the binder material with a free radical initiator, containing an organic peroxide, polymerized. As an additional catalyst component gaseous sulfur dioxide is used in catalytic amounts for curing the binder material.

CQ

AT 397 359

W 0078312

The invention relates to a process for the production of foundry molds and cores and their use for Leichttnetallguß.

In foundry technology, various types of binders are known which impart various desirable properties to the cores and molds during curing, ζ. B. in terms of erosion resistance, moisture resistance, mold release or, Ausschüttelbarkeit. In the production of molds or cores, a high production rate is also sought.

Modern mold and core manufacturing techniques began with the use of unsaturated drying oils of natural origin as binders. The best known example of a drying oil is linseed oil. On exposure to air, linseed oil and other unsaturated oils undergo oxidative polymerization to form solid highly crosslinked structures. The polymerization can be accelerated by heat or by chemical means. In the foundry industry, these binders are referred to as core oils. For the production of a core, the oil is mixed with sand and the sand mixture is brought into the desired shape. The hardening takes place by heating or prolonging the aging of the core. the form. Binders based on core oil may contain other components in addition to the oil component, ζ. B. oils derived from oils, unsaturated hydrocarbon resins and solvents. Processes for making foundry molds and cores using core oils have been known for about 50 to 60 years

About 25 to 30 years ago procedures were introduced that are faster than the Kemölverfahren. These so-called hot-box processes require thermal curing of the binder, which consists of thermosetting synthetic resins. Suitable thermosetting resins are ζ. As phenol-formaldehyde resins, urea-formaldehyde resins and furfuryl alcohol-formaldehyde resins. In addition to the thermal curing or polymerization of these binders, acids are also often used as catalysts.

About 10 years ago, high-speed, room-temperature process for the production of foundry molds and cores was developed. The binders used in these processes are based on urethane chemistry, i. H. The binders consist essentially of two liquid synthetic resin components, namely a phenol-formaldehyde resin and a polymeric isocyanate. The phenolic resin and the polyisocyanate are mixed with the sand and then used in either a cold-box or a no-bake system the sand coated with the two components is injected into a keratin box. Subsequently, a gaseous tertiary amine is passed through the Kemkasten to harden the binder or to solidify. This procedure is ζ. B. in U.S. Patent 3,409,579. In the no-bake process, the polyisocyanate, the phenolic resin and a catalyst are mixed simultaneously with the sand. The sand mixture is then poured into a core box or mold and remains flowable for some time. After this time, the catalyst causes a hardening or Polymerization and it quickly forms a core, since the binder components react quickly to a urethane binder. No-bake binders are ζ. B. in U.S. Patent 3,676,392.

Another binder system and its use in the foundry are described in U.S. Patent No. 3,879,339. There, a cold box (gas room temperature cure) process is employed using a foundry binder comprising an acid curable organic resin and an oxidizing agent. The binder component is cured with sulfur dioxide. The combination of sulfur dioxide + oxidizer results in the formation of sulfuric acid which cures the acid-curable organic resin. Essentially, sulfuric acid is thus formed in situ, which reacts with the resin and cures the binder

None of the mentioned foundries is of such broad applicability and adaptability that it can be considered universal and irreplaceable.

The object of the invention is therefore to provide a novel binder, which is based on a previously not used in foundry technology or other binder areas chemistry not applied It is particularly a foundry binder of the cold-box type can be provided which gives a rapid cure and in particular for casting Aluminum and other light metals

The invention relates to a process for the production of foundry molds and cores by mixing a binder material with a foundry mold material, Shaping the mixture and hardening the binder material, by distributing a binder material on the foundry mold material, which contains an ethylenically unsaturated monomer and / or polymer, makes the foundry mold material in the desired shape and the bonding material with a free radical initiator, containing an organic peroxide, polymerized characterized in that one uses as an additional catalyst component gaseous sulfur dioxide in catalytic amounts for curing the binder material.

From DE-AS 2,203,411 a cold-curing foundry molding composition is known which comprises a polymerizable monomer or oligomer for the preparation of the binder, in which an easily removable polymerization inhibitor is contained. In addition, a method for curing such a foundry molding composition is described, according to which the polymerization inhibitor is volatilized, absorbed or neutralized. As an inhibitor, SO 2 is preferably used

Thus, according to this proposal, the SOj is not used to achieve extremely rapid hardening, as in the present invention, but, on the contrary, to prevent hardening.

-2AT397359B

The inventive use of a peroxide together with SO₂ for the creation of a quick-hardening mechanism is therefore contrary to the disclosure of this disclosure.

German Offenlegungsschrift No. 2,908,198 describes acid-curable resins, that is to say no ethylenically unsaturated materials, as used in accordance with the invention. In contrast to the type of cure disclosed in this disclosure, the present invention provides a free-radical curing mechanism wherein the cure particularly comprises the interaction of ethylenically unsaturated groups, such as acrylic groups, with other ethylenically unsaturated groups through the interaction of SO₂With the peroxide free radicals are formed, which cause polymerization of the unsaturated groups. Any acid resulting from the mutual action of SO₂ and the peroxide could arise, does not participate in the polymerization in any way. Acids, such as sulfuric acid, would not lead to any curing of the binder system used according to the invention.

The inventively provided use of gaseous SO₂ in combination with a peroxide results in a substantially instantaneous cure of ethylenically unsaturated binder materials. Further, the process of the present invention not only enables extremely rapid curing, but also results in a binder having, after curing, the properties required for the production of molded articles.

As is well known, binder compositions in order to be suitable for molds for the production of foundry items must possess a number of important properties, some of which contradict one another.

For example, it is necessary that the composition be allowed to cure as much as possible at normal room temperature. Further, since the curing of the composition occurs while it is present as a thin film on the molding material and the molding material can dissipate heat, the curing does not necessarily have to run in the manner as when the binder is cured in the mass. In addition, foundry molds and cores must maintain the necessary strength until the metal solidifies in the mold, but they must lose strength during casting, so that after solidification of the metal, the cores or molds are easily cast out of the casting break. It can be seen from the enclosed examples that excellent dispensing properties are achieved by the method according to the invention, even with cast aluminum. This is a particularly important feature because the shaking out of aluminum castings presents particular problems because aluminum is cast at relatively low temperatures of approximately 700 ° C.

In particular, the binder is a room-temperature curable binder that is free-radically and polymerizable by chain extension and is suitable for bonding materials, particularly particulate solids. The molds and cores made with such a binder are characterized by superior disintegration properties when used to cast metals, particularly light metals cast at low temperatures, such as aluminum

As is known, foundry molds and molds are prepared by spreading a binder on sand or other molding material, bringing the sand into the desired shape and allowing the binder to harden or harden. The invention can be explained with reference to a binder, which is obtained by bringing two parts together. Part I is a binding substance or composition that is polymerizable and crosslinkable and that retains the sand or other molding material in the desired shape. Part II is an agent that effects the polymerization and crosslinking of Part I. This agent is referred to herein as a radical initiator. Crosslinking is understood to mean a chain construction that occurs when a polymer is attached either to another polymer or to a monomer. The term polymerization includes crosslinking, but also refers to chain extension with the sole participation of monomers.

Part I of the binder system may be referred to as an unsaturated composition which is radically crosslinkable or polymerizable. The unsaturated bonds are preferably terminal or pendant. Also internal unsaturated bonds are possible and the polymerization takes place in the combination with Part H. Depending on the method of preparation of component 1, it is also conceivable that a component I has both terminal and / or pendant as well as internal unsaturated bonds in the same component When crosslinking compositions (i.e. H. unsaturated polymers), the polymerization mechanism is presumably almost completely free-radical. When certain monomers are used in the binder composition, it is possible that the polymerization occurs partly by a mechanism other than the free radical mechanism. The term radical mechanism is therefore used for convenience only but describes the actual mechanism in almost all cases. In certain circumstances, however, other mechanisms besides the free radical mechanism may participate in the polymerization reaction. Curing is with Part Π, a free radical initiator comprising a peroxide and a catalyst. It has been found that unsaturated reactive monomers, polymers and mixtures thereof can be used as binder materials which cure immediately in the choice of particular free radical initiator catalysts. The monomers and polymers are preferably ethylenically unsaturated. For example, reactive polymers, which may also be referred to as oligomers or adducts and which preferably contain vinyl or acrylic bonds, may be used as binders which upon polymerization form a binder for foundries or molds

-3AT397359B

Sand surrendered. The free radical initiator (part Π) is mixed with the reactive polymer or monomer (part I) and forms free radicals which polymerize the binder to a binder. This combination of a peroxide and a catalyst is referred to herein as a radical initiator, which catalyst can be used not only as a chemical but also in the form of energy.

The radical initiator can be used to polymerize the materials of Part I in various ways. For example, you can mix the peroxide with Part I and distribute the mixture evenly on the sand. The sand is then shaped and exposed to the catalyst. Alternatively, the catalyst can also be added to Part I and the mixture applied to the sand, which is then brought to the desired shape. Then, the peroxide component of the radical initiator is added to the molded article, whereby polymerization is effected. It is also possible to separate the materials of Part I into two parts. The catalyst may be added to one portion and the peroxide to the second portion. If the two fractions are combined after at least one fraction has been applied to the material to be joined, the polymerization takes place. Depending on the nature of the catalyst or the apparatus and method of use used, this latter method may not be practical. In contrast, it is particularly useful in cases where the binder is used to bond non-particulate materials. The choice of different catalysts has a great influence on the type of polymerization of the binder and its rate of cure. When choosing suitable catalysts, it is z. B. the user is able to polymerize the binder immediately at room temperature or to delay the polymerization for some time and to complete it at elevated temperature. This controllability of the conditions at which the binder polymerizes is of great industrial importance.

As mentioned above, Part I is a polymerizable unsaturated monomer, polymer or mixture of such monomers and / or polymers. Examples of suitable monomers for Part I are a wide variety of mono-, di-, tri- and tetra-functional acrylates. Specific examples of these monomers are alkyl acrylates, hydroxyalkyl acrylates, alkoxy acrylates, cyanoalkyl acrylates, alkyl methacrylates, hydroxyalkyl methacrylates, alkoxyalkyl methacrylates, cyanoalkyl methacrylates, N-alkoxymethylacrylamides and N-alkoxymethyl methacrylamides. The functional monomeric acrylates are z. B. Hexanediol diacrylate and TetraäthylenglykoldiacrylaL Other usable acrylates are, for. B. Trimethylolpropane triacrylate, methacrylic acid and 2-ethylhexyl methacrylate. Polyfunctional acrylates are preferably used when the monomer is the only binder component of the binder system. As already mentioned, no crosslinking is carried out when monomers alone are used as the binding material. Also, besides the radical mechanism, other mechanisms may cause polymerization.

Examples of unsaturated reactive polymers which have been found to be particularly suitable for making the foundry binder are epoxy acrylate reaction products, polyester / urethane / acrylate reaction products, polyether acrylates and polyester acrylates. Unsaturated polymers useful as Part I are e.g. B. the commercial products ÜVITHANE 782 and 783 (acrylated urethane oligomers from Thiokol) and CMD 1700 (an acrylated ester of an acrylic polymer) and CELRAD 3701 (an acrylated epoxy resin) from Celanese. Reactive polymers can be obtained in various ways. A preferred method is to react a polyhydroxy compound or a polyol with a diisocyanate to form an isocyanate-terminated prepolymer. The prepolymer is then further reacted with a hydroxyalkyl acrylate to form an oligomer. A second suitable method is to react a polyisocyanate, preferably a diisocyanate, with a hydroxyalkyl acrylate. The reaction product is an adduct of these two materials. In addition, oligomers and adducts can be prepared simultaneously under suitable conditions.

In addition to the reactive unsaturated polymer, if appropriate, preferably a solvent, preferably a reactive solvent, is a constituent of the binding material. Depending on the nature of the unsaturated binding materials, inert solvents may also be used. The preferred solvent is an unsaturated monomeric compound, as described, for. B. mentioned above in the materials of Part I. Thus, Part I may comprise a mixture of these unsaturated monomers and unsaturated polymers referred to above as Part I partial materials. The best results are obtained when using a solution of an unsaturated reactive polymer and a monomeric unsaturated solvent. This combination appears to be more capable of copolymerization and crosslinking to form a binder matrix required to join either sand or other molding materials to a foundry grain or core or to bond other materials.

Part I of the binder system preferably comprises an unsaturated monomeric compound as a solvent besides the unsaturated polymer. As already mentioned, these monomers contain unsaturated bonds and therefore not only serve as solvents for the unsaturated polymer but are crosslinkable with the polymer. Each of the unsaturated monomers listed as Part I materials or their combinations are useful as solvents. Preference is given to ethylenically unsaturated monomers, in particular of the vinyl or acrylic type. Particularly preferred monomers which are suitable as solvents for unsaturated polymers are, for. B. Pentaerythritol triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, and tetraethylene glycol diacrylamide The amount of monomer in Part I can be 0 to 100%, based on the total weight of the Part I binder composition.

-4AT397359B

It is also possible to use the reactive polymer as Part I and the radical initiator without a solvent including an unsaturated monomer being present for the unsaturated polymer. One can also use the unsaturated monomer as Part I with the free radical initiator, but without the reactive polymer, to obtain a polymerized binder. However, neither of these two combinations is preferred. The binder system preferred as Part I comprises a reactive unsaturated polymer dissolved in a reactive diluent, preferably a monomeric unsaturated solvent, while Part II comprises a free radical initiator.

The radical initiator consists of two components. The first component is preferably an organic peroxide. As the first component, however, any substance can be used which forms free radicals when exposed to a catalyst. The peroxide content may vary within wide limits and depends to some extent on the catalyst used. In general, however, 0.5 to 2% peroxide, based on the weight of the binder material (Part I), gives a satisfactory bond under most conditions. Examples of preferred peroxides are tert-butyl hydroperoxide, cumene hydroperoxide and methyl ethyl ketone peroxide. Hydroperoxides are preferred over peroxides. In the case of peroxides, uneven curing was observed. Mixtures of peroxides and hydroperoxides as well as mixtures of hydroperoxides are also usable.

The used as an additional catalyst component SO2 is present only in catalytic amounts. The exposure time of the gas to the sand mixture may be only 1/2 second or less and the binder component cures on contact with the catalyst. When using SO2 as a catalyst in a cold-box process, this is suspended in a known manner in a carrier gas stream. The carrier gas is usually nitrogen. Already 0.5% SO2, based on the weight of the carrier gas, are sufficient for the polymerization. It is also possible to expose the binder component to the SO2 without the presence of a carrier gas.

Part I may optionally also contain other ingredients. For example, wetting and defoaming additives are useful. Silanes, preferably unsaturated silanes, e.g. As vinyl silanes, are particularly suitable additives.

The binders of the invention have the following advantages as foundry binders. The disintegration properties of the binder used for the aluminum casting are excellent. It has been found that the binder in cast aluminum allows excellent disintegration or shake-off behavior with minimal external energy consumption. The binder also gives good strength values. The processing time of the mixed with Part I sand is quite long. The castings produced with the binder have very good surface quality. The production rate of cores and molds is high when using this binder system, especially when SO2 is used as a catalyst.

In foundry practice, Part I and a component of the free radical initiator, preferably the peroxide, are mixed in the usual way with sand or other suitable foundry mold material. The sand mixture is then formed into the desired shapes or cores in a conventional manner. The second component of the free radical initiator, preferably the catalyst and especially sulfur dioxide, is allowed to act on the sand mixture, with immediate polymerization of the Part I binder materials to form the binder of the present invention

The following examples illustrate the invention. All parts and percents are by weight unless otherwise stated.

example 1

Gelling tests are performed with various unsaturated monomers and polymers to determine their tendency to polymerize and rate. In these tests, about 1.5 to 2 grams of unsaturated monomer or polymer (part I) are mixed with 0.03 grams of tert-butyl hydroperoxide (peroxide component of the free radical initiator). The mixture is then exposed to SO 2 gas (catalyst of the free radical initiator) by either the gas is dispersed in the liquid (blowing in) or creating a SO2 atmosphere over the liquid (contacting). The following results show that all unsaturated monomers and polymers polymerize. The cited compounds are therefore potential binders. Compounds that undergo rapid polymerization or gelation are of particular interest as foundry binders for the high speed cold-box process of making molds and cores.

Part I Result of the evaluation

Acrylic acid fast, on contact with SO₂

Ethyl acrylate slow, on contact with SO2 n-butyl acrylate slowly, upon contact with SO2

Isobutyl acrylate slow in contact with SO2

-5AT397359B

<td>Tein</td><td>polymerization result</td>

<td>2-ethylhexyl acrylate</td><td>fast, in contact with SO2</td>

<td>isodecyl</td><td>fast, in contact with SO2</td>

<td>2-Äthoxyäthylacrylat</td><td>fast, in contact with SO2</td>

<td>Äthoxyäthoxyäthylacrylat</td><td>fast, in contact with SO2</td>

<td>Butoxyäthylacrylat</td><td>fast, in contact with SO2</td>

<td>hydroxyethyl acrylate</td><td>fast, in contact with SO2</td>

<td>hydroxypropyl acrylate</td><td>fast, in contact with SO2</td>

<td>glycidyl</td><td>fast, in contact with SO2</td>

<td>dimethylaminoethyl</td><td>fast, in contact with SO2</td>

<td>Cyanoäthylacrylat</td><td>fast, in contact with SO2</td>

<td>Diacetone acrylamide in methanol, 50%</td><td>fast, in contact with SO2</td>

<td>Acrylamide in methanol, 50%</td><td>fast, in contact with SO₂</td>

<td>(N-methylcarbamoyloxy) -äthylacrylat</td><td>fast, in contact with SO2</td>

<td>Methyl acrylate</td><td>fast, in contact with SO2</td>

<td>Phenoxyäthylacrylat</td><td>fast, in contact with SO2</td>

<td>benzyl</td><td>fast, in contact with SC&gt; 2</td>

<td>Äthylenglykolacrylatphthalat</td><td>fast, in contact with SO2</td>

<td>melamine</td><td>fast, in contact with SC&gt; 2</td>

<td>Diäthylenglykoldiacrylat</td><td>fast, in contact with SO2</td>

<td>hexanediol</td><td>fast, in contact with SO2</td>

<td>butanediol</td><td>fast, in contact with SO₂</td>

<td>Triäthylenglykoldiacrylat</td><td>fast, in contact with SO2</td>

<td>Tetraäthylenglykoldiacrylat</td><td>fast, in contact with SO2</td>

<td>neopentylglycol</td><td>fast, in contact with SO2</td>

<td>1,3-butylene glycol</td><td>fast, in contact with SO₂</td>

<td>trimethylolpropane</td><td>fast, in contact with SO2</td>

<td>pentaerythritol</td><td>fast, in contact with SO2</td>

<td>methacrylic acid</td><td>fast, in contact with SO2</td>

<td>methyl methacrylate</td><td>slow, when in contact with SC&gt; 2</td>

<td>2-ethylhexyl methacrylate</td><td>slow, in contact with SO2</td>

<td>hydroxypropyl methacrylate</td><td>fast, in contact with SO2</td>

<td>glycidyl</td><td>fast, in contact with SO2</td>

<td>dimethylaminoethyl</td><td>fast, in contact with SO2</td>

<td>ethylene glycol dimethacrylate</td><td>fast, in contact with SO2</td>

<td>Trimethylolprpantrimethacrylat</td><td>fast, in contact with SO2</td>

<td colspan="2">Glycerine-derived acrylated urethane,</td>

<td>65% in MIAK / HiSol-10</td><td>fast, in contact with SO2</td>

<td>N-methylolacrylamide in water, 60%</td><td>fast, in contact with SO2</td>

<td>N- (isobutoxymethyl) -acrylamide in methanol, 50%</td><td>fast, in contact with SO₂</td>

<td>Epocryl R-12 (shell) acrylated epoxy, 80% in acetone</td><td>slow, in contact with SO2</td>

<td colspan="2">UVITHANE 783 (Thiokol / Chem. Div.)</td>

<td>acrylated urethane oligomer</td><td>fast, in contact with SO₂</td>

<td colspan="2">AROPOL 7200 (ASHLAND) unsaturated polyester resin,</td>

<td>60% in acetone</td><td>slow, in contact with SO2</td>

<td colspan="2">RICON 157 (Colorado Specialty Chemical)</td>

<td>unsaturated hydrocarbon resin, 50% in acetone</td><td>slow, in contact with SO2</td>

<td colspan="2">Hydroxy PBG-200 (Hystl Co.) unsaturated</td>

<td>Hydrocarbon resin, 50% in acetone</td><td>slow, in contact with SO₂</td>

-6AT397 359B

Example 2

An unsaturated polymer is prepared by reacting 1 mole of pentanediol and 4 moles of hydroxyethyl acrylate with 3.0 moles of tolylene diisocyanate. To catalyze the reaction, 0.14%, based on solids content, of dibutyltin dilaurate is used. Hydroquinone monoethyl ether is used as inhibitor. The reaction is carried out in a reaction medium (solvent) consisting of ethylhexyl acrylate and hydroxyethyl acrylate. To carry out the reaction, a mixture of TDI and solvent is fed into the reaction vessel. Then you are added to pentanediol and then hydroxyethyl acrylate. After completion of the addition of the Hydroxyäthylacrylats the catalyst is added and the reaction is carried out with the introduction of air The reaction proceeds 2.1 hours at 40 to 45 ° C, after which the temperature is raised to 80 to 85 ° C and the reaction 4.3 hours Add 0.03% inhibitor and continue the reaction for 1/2 hour. Then allowed to cool the product. It contains 59.2% of non-volatiles, which corresponds to the theoretical value of 60%. The viscosity of the product is 6.0. St of the unsaturated polymer are mixed with 1.6 g of acrylic acid, 10.7 g of diethylene glycol diacrylate, 9.9 g of trimethylolpropane trimethacrylate and 2.0 g of vinylsilane mixed with acrylic acid, diethylene glycol diacrylate and trimethylolpropane triacrylate are unsaturated monomers. This solution of unsaturated polymer and unsaturated monomers is referred to as Part I. 1 g tert-butyl hydroperoxide (peroxide component of the radical initiator) is added to the solution of unsaturated polymer and unsaturated monomers.

Wedron 5010 sand (washed and dried fine-grained quartz sand AFSGFN 66) is introduced into a suitable mixing device. Part I and the peroxide component of the free radical initiator are mixed with the sand until uniform distribution is achieved. The content of Part I + peroxide is 2%, based on the weight of the sand.

The sand mixture is injected into a conventional core box to produce dumbbell-shaped standard tensile test jaws. The dumbbell-shaped testkems are then cured by exposing them to the catalyst component of the free radical initiator, i. H. gaseous sulfur dioxide. The cores are exposed to the SC 2 catalyst for about 1/2 second (gas time), after which the catalyst is removed by purging with nitrogen for 15 seconds and the cores are removed from the box. The tensile strength of the core (kg / cm²) is 15.68 when removed from the box, 14.41 after 3 hours and 15.96 after 24 hours.

Dumbbell-shaped cores, similar to the cores described above, are used for aluminum casting outfeed tests. Seven dumbbell tensile specimens are placed in a mold. The mold has a runner system and is designed to produce hollow castings with an all-round metal thickness of about 6.35 mm. The casting is provided at one end with an opening through which the core can be removed. Aluminum of about 704 ° C, melted from aluminum ingots, is poured into the mold. After approximately 1 hour of cooling, the aluminum castings are broken off the runner system and removed from the mold to perform shake-out tests.

For the shakeout tests, the casting is placed in a container of 3.8 liters capacity. The container is then placed on a shaking mechanism and shaken for 5 minutes. The weight of the sand core removed from the casting in this way is compared with the initial weight of the sand core and the degree of shaking ( %) expressed in sand which remains in the casting after the described shaking is scraped out and also weighed. The Sandkem bound with the binder described above gives a Ausschütttelgrad of 100%. The shakeout test described is not a standard test but applicants are not aware of a standard test to measure this property. The test used, however, allows for evaluation of the disintegration properties of the binder and a comparison of the binder's relative disintegration properties. The percentages given are subject to fluctuations, but are reliable indicators.

For example, the third

sand

Wedron 5010 from 233 to 25.6 ° C (Teil.I)

a) unsaturated monomer

b) unsaturated polymer Preparation of the unsaturated polymer

1.6 g of acrylic acid, 10.7 g of diethylene glycol diacrylate, 9.9 g

Trimethylolpropane trimethacrylate g polymer prepared in the following manner

i)

in) iv)

v)

Polyisocyanate, molar equivalent of polyol, molar equivalent of acrylate, molar equivalent of catalyst inhibitor

TDI, 4

Glycerol, 1

Hydroxyethyl acrylate, 5

Dibutyltin dilaurate, 0.14%

Hydroquinone monomethyl ether

-7AT397 359B

<td>vii)</td><td>Solvent,%</td><td>Ethylhexyl acrylate and hydroxyethyl acrylate, 40%</td>

<td>viii)</td><td>Temp./time, ° C / h</td><td>2.13 h at 40 to 45 ° C and then for 4.8 h at 80 to 85 ° C.</td>

<td>ix)</td><td>Viscosity, St</td><td>16.0</td>

<td>x)</td><td>non-volatile components,% gef.</td><td>63.9</td>

<td></td><td>theor.</td><td>60.0</td>

<td>c) additive, g</td><td colspan="2">Vinylsilane, 2.0</td>

<td colspan="3">Radical initial part II)</td>

<td>a) peroxide component</td><td colspan="2">tert-butyl hydroperoxide, 22%</td>

<td>b) catalyst component</td><td>SC ^ gas</td><td></td>

<td>Gas time, s</td><td>0.5</td><td></td>

<td>Rinsing time, s</td><td>15 with N2</td><td></td>

<td colspan="3">Tensile strength, kg / cnr</td>

<td>at removal</td><td>12.51</td><td></td>

<td>3h</td><td>1526</td><td></td>

<td>24 hours</td><td>16.38</td><td></td>

<td colspan="2">Binder content (part I + peroxide component) 2%</td><td></td>

<td>poured metal</td><td>aluminum</td><td></td>

<td>Discharge rate,%</td><td>100</td><td></td>

<td>Example?</td><td>4</td><td>Second</td>

<td>sand</td><td>Wedron 5010</td><td>Wedron 5010</td>

<td colspan="3">(TSIH)</td>

<td>a) unsaturated monomer</td><td>1.6 g of acrylic acid, 10.7 g of di-</td><td>2.2 g of hydroxyethyl acrylate,</td>

<td></td><td>ethylene glycol diacrylate,</td><td>20.8 g of dicyclopentenyl</td>

<td></td><td>9.9 g of trimethylolpropane tri-</td><td>acrylate, 17.3 g (N-methyl</td>

<td></td><td>acrylate</td><td>carbamoyloxy) -äthylacrylat</td>

<td>b) unsaturated polymer</td><td>20 g of the polymer prepared in the following manner</td><td></td>

Preparation of the unsaturated polymer

<td>i) polyisocyanate, molar equivalent</td><td>TDI.3</td><td></td>

<td>ii) polyol, molar equivalent</td><td>Olin 20-265 (polyoxypropylene</td><td></td>

<td>iii) acrylate, molar equivalent</td><td>glycol), 1 Hydroxyethyl acrylate, 4</td><td></td>

<td>iv) catalyst</td><td>Dibutyltin dilaurate, 0.14%</td><td></td>

<td>v) inhibitor</td><td>Hydroquinone monomethyl ether</td><td></td>

<td>vii) Solvent,%</td><td colspan="2">Ethylhexyl acrylate and hydroxyethyl</td>

<td>viii)</td><td>acrylate, 40% Temp./time, ° C / h</td><td>2.1 h at 40 to 45 ° C and</td>

<td>ix) Viscosity, St</td><td>4.75 h at 80 to 85 ° C 42</td><td></td>

<td>x) non-volatile components,% gef.</td><td>592</td><td></td>

<td>theor.</td><td>60.0</td><td></td>

<td>c) additive, g</td><td>Vinylsilane, 2.0</td><td></td>

<td colspan="3">Free radical initiator (part ID</td>

<td>a) peroxide component</td><td>11.3% cumene hydroperoxide</td><td>2.4% tert-butylhydroxy</td>

<td>b) catalyst component</td><td>SO₂-Gas</td><td>peroxide SO2 gas</td>

<td>Gas time, s</td><td>0.5</td><td>1</td>

<td>Rinsing time, s</td><td>15 with N2</td><td>15 with N2</td>

Tensile strength, kg / cm

<td>at removal 3h</td><td>11.25</td><td>1.76</td>

<td>24 hours</td><td></td><td></td>

<td>48 h</td><td>16.31</td><td></td>

<td>Binder content (part I + peroxide</td><td>2%</td><td>2%</td>

<td>component)</td><td></td><td></td>

<td>poured metal</td><td>aluminum</td><td></td>

<td>Discharge rate,%</td><td>100</td><td></td>

<td>Bqi§pi? Lc</td><td>£</td><td>1</td>

<td>sand</td><td>Wedron 5010</td><td>Wedron 5010</td>

<td>a) unsaturated monomer</td><td>40 g of pentaerythritol</td><td>7/2 g of acrylic acid, 21.4 g of</td>

<td></td><td>acrylate</td><td>ethylene glycol diacrylate,</td>

g trimethylolpropane triacrylate

<td colspan="3">Free radical initiator (Part II)</td>

<td>a) peroxide component</td><td>2.4% tertiary butyl hydroperoxide</td><td>2.4% tertiary butyl hydroperoxide</td>

<td>b) catalyst component</td><td>SO₂-Gas</td><td>SO₂-Gas</td>

<td>Gas time, s</td><td>03</td><td>1</td>

<td>Rinsing time, s 9 Tensile strength, kg / cm</td><td>15</td><td>10</td>

<td>at removal 3h 24 hours</td><td>337</td><td>9.14</td>

<td>Binder Content (Part I + Peroxide Component) Cast Metal Discharge Degree,%</td><td>2%</td><td>2%</td>

Examples

Sand (part i)

a) unsaturated monomer £

Wedron 5010 lbs

Port Crescent

b) unsaturated polymer

i) polyisocyanate,

Molar equivalent ii) polyol, molar equivalent iii) acrylate, molar equivalent iv) catalyst

v) inhibitor vii) solvent,% viii) temp./time, ° C / hx) Viscosity

x) non-volatile components,% gef.

theor.

made in the following way, 40 g TDI, 3

Olin 20-265,1

3.2 g of acrylic acid, 21.4 g of diethylene glycol diacrylate, 19.8 g of trimethylolpropane trimethylacrylate, as in Example 4.40 g

Hydroxyethyl acrylate, 4 dibutyltin dilaurate, 0.14% hydroquinone monomethyl ether, 0.07% pentoxone (93.7)

Hydroxyethyl acrylate, 35% h at 40 to 45 ° C and then 4 h at 80 to 85 ° C thixotropic after 3 days

63.1

c) additive, g

2.0 g of vinylsilane A-172, vinylsilane

1.6 g of acrylic acid

-9AT397359B

Free radical initiator (part ID

a) peroxide component

b) catalyst component gas time, s

Purge time, so

Tensile strength, kg / cm at removal 3h 24h

cold strength

Binder Content (Part I + Peroxide Component) Cast Metal Degree of Discharge,% Tert-butyl Hydroperoxide, 2 ^%

SOg gas with N2

3.73

6.54

10,90

2% tert-butyl peracetate, 6 g 90 s heating to 450 ° C

27.5

11/25

2%

Examples

Sand (Part D

a) unsaturated monomer

b) unsaturated polymer

eat

Wedron 5010

Wedron 5010 as in Example 10

1.6 g of acrylic acid, 9.9 g of trimethylolpropane triacrylate prepared on the below

Way, 20 g

Preparation of the unsaturated polymer

<td>i) polyisocyanate, molar equivalent</td><td colspan="2">TDI, 3.5</td>

<td>ii) polyol, molar equivalent</td><td>Glycerol / diethylene glycol mixture (1: 1), 1</td><td></td>

<td>iii) acrylate, molar equivalent</td><td>Hydroxyethyl acrylate, 45</td><td></td>

<td>iv) catalyst</td><td>Dibutyltin dilaurate, 0.14%</td><td></td>

<td>v) inhibitor</td><td colspan="2">Hydroquinone monomethyl ether, 0.07%</td>

<td>vii) Solvent,%</td><td>Athylhexyl acrylate + hydroxyethyl acrylate (4: 6), 40%</td><td></td>

<td>viii)</td><td>Temp./time, ° C / h 4.8 hours at 80 to 85 ° C</td><td>2 h at 40 to 45'C and then</td>

<td>ix) Viscosity, St</td><td>10</td><td></td>

<td colspan="3">x) non-volatile components,%</td>

<td>gef.</td><td>59.9</td><td></td>

<td>ther.</td><td>60.0</td><td></td>

<td>c) additive, g</td><td>Vinylsilane A-172.2 HiSol 10,10,7</td><td></td>

<td colspan="3">Free radical initiator (part ΙΓ)</td>

<td>a) peroxide component</td><td>70% tert-butyl hydroperoxide, 22%</td><td></td>

<td>b) catalyst component</td><td>SO2 "Gös</td><td>05% SO₂ in N₂ as a carrier gas</td>

<td>Gas time, s</td><td>05</td><td>0.5</td>

<td>Rinsing time, s</td><td>15 with N2</td><td>none</td>

<td colspan="3">0 Tensile strength, kg / cm</td>

<td>at removal</td><td>16.03</td><td>492</td>

<td>3h</td><td>15.96</td><td>8.58</td>

<td>24 hours</td><td>18.07</td><td>15.68</td>

<td>Binder content (part I + peroxide</td><td>2%</td><td>15%</td>

<td colspan="3">component)</td>

<td>poured metal</td><td>aluminum</td><td></td>

<td>Discharge rate,%</td><td>100</td><td></td>

Example 12

Sand (part n

a) unsaturated monomer

b) unsaturated polymer

Preparation of the unsaturated polymer

i) polyisocyanate, molar equivalent ii) polyol, molar equivalent iii) acrylate, molar equivalent iv) catalyst

v) inhibitor vii) solvent,% viii) temp./time, ° C / h ix) Viscosity, St

x) Non-volatile ingredients,% gef.

ther.

c) additive, g

Wedron 5010

1.6 g of acrylic acid, 5.49 g of diethylene glycol diacrylate,

9.9 g of trimethylolpropane triacrylate prepared in the following manner, 20 g

TDI, 4

Glycerol, 1

hydroxyethyl acrylate

Dibutyltin dilaurate, 0.14

Hydroquinone monomethyl ether, 0.03

Methyl isoamyl ketone / HiSol 10 (65:35) 35%

1.75 h at 40 to 45 ° C and then 4.5 h at 80 to 85 ° C 10

64.1

Vinylsilane, 2.0

HiSoll0,5,3

Free radical initiator (part ID

a) peroxide component

b) catalyst component gas time, s

Rinsing time, s

Tensile strength, kg / cm ^ at removal 3h 24h

Binder content (part I + peroxide component) Cast metal Discharge grade,% tert-butyl hydroperoxide, 2.2% 1% SC&gt; 2 in N2 as carrier gas 20 None

15.33

11.04

16.38

aluminum

100

Wedron 5010

Example 13

Sand (TeiLD.

a) unsaturated monomer

b) unsaturated polymer

Preparation of the unsaturated polymer

i) polyisocyanate, molar equivalent ii) polyol, molar equivalent iii) acrylate, molar equivalent iv) catalyst

v) inhibitor vii) solvent,% viii) temp time, ° C / h ix) Viscosity, St

x) non-volatile components,% gef.

theor.

c) additives, g

1.6 g of acrylic acid, 5.49 g of diethylene glycol diacrylate, 9.9 g of trimethylolpropane triacrylate prepared in the following manner, 20 g

TDI, 4

Glycerol, 1

hydroxyethyl acrylate

Dibutyltin dilaurate, 0.14

Hydroquinone monomethyl ether, 0.03

Methyl isoamyl ketone / HiSol 10 (65:35), 35%

1.75 h at 40 to 45 ° C and then 4.5h at 80 to 85^OC 10

64.1

Vinylsilane, 2.0

HiSoll0,53

-11AT397 359 B

Free radical initiator (part ID

a) peroxide component

b) catalyst component gas time, s purge time, s

Tensile strength, kg / cm ^ at removal

3h

24 hours

Binder Content (Part I + Peroxide Component) Cast Metal Degree of Discharge,% Tert-butyl Hydroperoxide, 23%

SC ^ gas with air

12.44

6.68

1035

aluminum

100