DE3145670A1 - RELEASE AND LUBRICANTS FOR THE TREATMENT OF CASTING MOLDS, IN PARTICULAR FOR THE DIE CASTING OF IRON ALLOYS - Google Patents

Description

RELEASE AGENTS AND LUBRICANTS FOR TREATMENT OF CASTING FORMS, IN PARTICULAR IN THE PRESSURE CASTING OF IRON ALLOYS

The invention relates to a release agent and lubricant for treating casting molds, in particular during die casting of iron alloys, containing finely ground material Graphite in an amount of 0.5 to 50 parts by weight, possibly finely crushed aluminum powder in in an amount from 0.05 to 15 parts by weight or lithium aluminum hydride in an amount of 0.05 to 10 parts by weight or a mixture thereof, which is in a hydrocarbon or aqueous medium are dispersed.

To prevent the molten metal from sticking to the mold and seizing its moving parts, release agents and lubricants are applied to the active surface * of the casting mold before the casting process. These form then a fine film between the casting mold and the casting, which allows the casting to be removed from the Casting mold ensures.

Known release agents and lubricants for treating the molds of die casting systems are on the one hand from On the basis of petroleum products existing solvent types, on the other hand of water-thinnable. Guys that consist on the basis of aqueous mineral oil emulsions.

For example, there is a mixture of cylinder oil known with petroleum and preservative petroleum jelly or aluminum powder "

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There is also a mixture of low-viscosity paraffin oil distillate known with engine lubricating oil on a hydrocarbon base of hard paraffin, wax and graphite

To lubricate and treat the casting molds

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oils, fats and waxes, including _o their mixtures with an addition of adipic acid, succinic acid or their Esteren or alkanolamine · to increase the lubricating effect used.

Another type of lubricating and separating fluid for die casting processes are aqueous, mineral oils Emulsions, with polyoxyethylene as emulsifier

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-Adducts of fatty acids, especially stearic and oleic acids, and, moreover, to increase the lubricity, sodium triphosphate, salts of dithiophosphonic acid with alkanolamines are used »The latter prevent the precipitation of solid hard water or a increased possibility of mold corrosion «,

Likewise, the lubricating and cooling liquids for hot metalworking companies contain water, Mineral oils and ethoxylated synthetic fatty acids as Emulsifiers,

Another water-thinnable agent for treating molds in the die casting of non-ferrous metals contains a mixture of mineral oils, glycerides of fatty

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acids and, as emulsifiers, alkyl polyglycol ethers or alkyl sulfate, where the alkyl group in question has from twelve to twenty carbon members in the molecule.

Furthermore, an agent is known which is made from animal or vegetable fats on the basis of esterified fatty acids such as palinitic, myristic, zerachin, lanopalmitic, lanomyristic and lanozerachinic acid together with ceryl alcohol, lanolin alcohol, carnaubabutyl alcohol and other cyclic polyterpenes from alkyl polyglycol ethers, where alkyl has 8 to 12 carbon atoms in the chain and the molecule has 5 to 25 members in the äthoxy-Iierteη chain, further from light and medium oils obtained by petroleum vacuum distillation, which have a flash point of at least 150 ⁰ C and through a viscous

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position from 16 to 22 mm .sec. are characterized, furthermore from sodium dinaphthyl methane disulfonate, from fine with

01 Graphite made into paste, made from paste with mineral oil or carboxymethyl cellulose oil processed aluminum

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nium powder, from dissolved in an excess of oleic acid and characterized by an acid number of 80 to 120 mg KOH / g

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ized condensation product of oleic acid with diethylenetriamine and consists of water «,

In addition to the lubricating and separating effects - in particular during die casting of iron alloys - the cooling effect exerted on the mold is an important property

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of such means. In general, it can be stated that that the water-thinnable release agents have better cooling effects than the solvent types «

The use of the above-mentioned means for treating the molds in the die casting of iron alloys is not sufficient to reduce the thermal stress on the casting molds, so that they have a very short service life.

The present invention is intended to achieve the above Eliminate disadvantages of the prior art and its underlying task is a release agent and lubricant for the treatment of casting molds, in particular for the die casting of iron alloys, containing finely comminuted material Graphite in an amount of 0.5 to 50 parts by weight, possibly finely comminuted aluminum powder in an amount of 0.05 to 15 parts by weight or lithium aluminum hydride in an amount of 0.05 to 10 parts by weight or a mixture thereof, which is in a hydrocarbon or dispersed in aqueous medium.

According to the invention, this object is achieved in that the separating agent and lubricant also have one. the oxides of Iron, tungsten, vanadium, wigmut, zirconium or titanium or a mixture of at least two of these Contains oxides in an amount of 0.5 to 10 parts by weight.

The "hydrocarbon medium" includes mineral oils, Obtained through crude oil distillation in the entire range from light to medium to heavy oils, animal fats of high stability such as wool fat, synthetic

Oils such as synthetic bovine foot oil, waxes and paraffins or mixtures of some or "all of the above"

The "aqueous medium" is water, the dissolved thickening agent such as carboxymethyl cellulose, dispersing agent such as sodium dinaphthyl methane disulfonate and other additives to increase the wettability of hot surfaces, to avoid corrosion of metal molds, to suppress bacteriological decomposition of the medium etc. may contain.

Both media can be mixed with emulsifiers such as ζ.Β, gthoxylated fatty alcohols with 8 to 20 carbon atoms in the molecule and from 5 to 25 links in the stoxylated chain or of alkylphenyl polyglycol ether,

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where alkyl has 6 to 12 ethylene oxide members, are mixed together _e

The release agent and lubricant according to the invention has the advantage to that when touching the iron alloy melt an endothermic reaction with this agent applied to the working surface of the casting mold takes place, which is the first strongest, from the point of view of

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Mold life absorbs decisive thermal shock. This endothermic reaction consists in a reduction of metal oxide to lower oxides, possibly metals,

The release agent and lubricant according to the invention is made by applying a layer to the working surface of the Casting mold applied before metal is poured in »

Some preferred compositions of the release agent and lubricant according to the invention are as follows Examples can be found.

example 1

In a double-walled with a stirrer. Kettles were 1.6 parts by weight of a mixture of ethoxylated Fatty alcohols with 12 to 18 carbon atoms and with 10 to 2C ethylene oxide members in the molecule and 0.7 Part by weight of ethoxylated alkylphenol with 9 carbon

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8toffatomen in the chain and 9 ethylene oxide links in the Molecule melted at a temperature of 60 to 80 ° C. Then 5.6 parts by weight of light and middle oils obtained by vacuum distillation of with a flash point of at least 150 C and a viscosity of 16 to 22 mm .see. at 50 ° C characterized Petroleum, 5.0 parts by weight of wool fat and one part by weight of finely ground, previously made into paste with the help of a by a flash point of at least

150 ° C. and a viscosity of 16 to 22 mm ² .see. " ^{1 of the} graphite characterized mineral oil characterized at 50 ° C. The mixture was then thoroughly homogenized and cooled to 40 ° C. In a separate vessel, 84 parts by weight of carboxymethyl cellulose solution were passed through Dissolve 3 parts by weight in 81 parts by weight of water. 2 parts by weight of sodium dinaphthyl methanedisulfonate were added to this amount, whereupon these two basic solutions were mixed together and homogenized in the double-walled kettle. The emulsion thus obtained was 0.5 part by weight of iron / II, III / ~ oxide 0.1 to 2 μm particle size was added and the whole thing was thoroughly homogenized.

Example 2

In a double-walled boiler wur.den 6 parts by weight of low and medium oils obtained by vacuum distillation of by a flash point of at least 150 C and a viscosity of 16 to 22mm .see at 50 ⁰ C-characterized Petroleum and 3.3 parts by weight of lanolin inserted . After this mixture was heated to 70 ° C., 1.7 parts by weight of ethoxylated fatty alcohols with 12 to 18 carbon atoms and 10 to 20 carbon atoms were in it

Ethylene oxide members in the molecule, 0.7 part by weight of nonylphenyldodecyl glycol ether and 1.5 parts by weight of the finest

previously crushed to paste with the help of a mineral oil processed graphite dissolved with constant stirring. In a separate vessel, a solution of 84 parts by weight of carboxymethyl cellulose was made by dissolving 5 parts by weight of! carboxymethyl cellulose in 81 parts by weight of water. This set of solutions were

2 parts by weight of Natriumdinaphtylmethandisulfonate and

3 parts by weight of iron sesquioxide hydrate (alpha modification) from 0.1 to 2 / um particle size added. These Both basic solutions were mixed together in a double-walled kettle and homogenized at 40 C.

Example 3

In a double-walled kettle equipped with a stirrer, 5 »8 parts by weight of a mixture of light and medium oils, obtained by vacuum distillation of a flash point of at least 150 ° C. and a viscosity of 16 to 22 mm. Sea.""At 50 ° C. characterized petroleum is heated to a temperature of 70 to 80 C ,. In the oil heated in this way, 1.55 part by weight of ethoxylated fatty alcohol with 12 to 18 carbon atoms in the molecule and 0.6 part by weight of nonylphenyldodecyl glycol ether were dissolved. This mixture was homogenized and 'cooled to 40 ⁰ C with constant stirring 2 parts by weight of him 2.9 parts by weight of wool fat, of feinstzer-

small graphite previously processed into paste with the help of a mineral oil, 1.2 parts by weight of condensate

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tion product of oleic acid with diethylenetriamine, dissolved

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in an excess of oleic acid, its amount by acid number of 100 mg / KOH, and 8 parts by weight of zirconia of 0.1 to 2 µm in particle size one after the other, was added, in a separate vessel prepared a carboxymethyl cellulose solution by dissolving 2 parts by weight of carboxymethyl cellulose in 81 parts by weight of water. The solution became 2.1 parts by weight of sodium dinaphthyl methane disulfonate added. These were last in the double-walled cauldron two basic solutions mixed together and homogenized to form the final release agent and lubricant.

Example 4

In a vessel, a mixture of 50 parts by weight of cylinder oil (kinematic viscosity 37-53 mm _o sec "at 100 ⁰ C;. Flash point in an open crucible of 285 ° C) and 10 parts by weight of paraffin (solidification point 58-60 ⁰ C ) heated with stirring. After the paraffin had melted and the temperature of the homogenized bath had dropped to 60 ° C., 30 parts by weight of graphite, 9.5 parts by weight, were added to the mixture

of iron sesquioxide hydrate (alpha-iv modification) and 9.5 Parts by weight of lithium aluminum hydride added successively with intensive stirring

Example 5

A mixture of 30 parts by weight of cylinder oil (kinematic viscosity from 25 to 37 mm .see. At 10O ⁰ Cj flash point in an open crucible of 240 ⁰ C) and 20 parts by weight of paraffin (solidification point from 56 to 58 ⁰ C) was placed in a vessel Stir heated. After the paraffin had melted and the temperature of the homogenized bath had dropped to 65 ° C., 40 parts by weight of finely comminuted graphite and one part by weight of iron sesquioxide hydrate (alpha modification) were added in succession with stirring.

Example 6

In a vessel, a mixture of 30 parts by weight of low and medium oils obtained by vacuum distillation of by a flash point of at least 150 ⁰ C and a viscosity of 16 mm to 22 mm _o sec _o "uncharacterized at 5O ⁰ C petroleum, 50 parts by weight of extraction oil obtained by deasphalting and dewaxing residues after petroleum vacuum distillation

digen heavy oils, 10 parts by weight of paraffin (solidification point of 56 to 58 ⁰ C) and 5 parts by weight of finely comminuted graphite made into a paste, heated o After the temperature of the homogenized bath had dropped to 70 ⁰ C, it was given 2 parts by weight of titanium dioxide in the form of a finely comminuted pigment and one part by weight of lithium aluminum hydride is added while stirring vigorously »

Example 7

In a vessel, 30 parts by weight of extraction oil, obtained by deasphalting and dewaxing heavy oils remaining after petroleum vacuum distillation, a mixture of 50 parts by weight of light and medium oils, obtained by vacuum distillation from through a flash point of at least 150 C and a viscosity of 16 to 22 mm .see at 50 ⁰ C characterized petroleum, 5 parts by weight of paraffin (solidification point from 56 to 58 C), 10 parts by weight of aluminum powder and 7 parts by weight of finely comminuted graphite made into a paste. With the temperature at 70 ⁰ C 9.5 parts by weight of finely powdered titanium dioxide were mixed with thorough homogenization in the bathroom "

The release agent and lubricant according to Example 1 was tested during the die casting of iron alloys. It was applied to the mold before each casting process with the aid of a pneumatic spray gun «Before application one part of the agent was diluted with ten parts of water. Experimentally, the smearing and separating effects were good of the agent according to the invention proved; no sediment was found in the mold »Also the cooling effect the agent was very good, which had the effect of extending the life of the mold insert. When testing of more dilute agents, in the case of the castings of medium and high complexity, the most evident Separating, lubricating and cooling ability of the agent as insufficient. The agent according to Example 1 is suitable for Treating the molds for pouring simple castings at a dilution ratio of up to 1: 15, in the case of castings of medium complexity of at most 1: 1O "

The separating and lubricating agent according to Example 2 has higher lubricating, separating and and cooling capabilities in comparison with the agent according to Example 1 proved. In the case of castings of medium complexity made of iron alloys, the effectiveness of the agent was still at the dilution ratio of 1: IO was quite sufficient for very complicated castings

it is necessary to ensure sufficient effectiveness, to increase the concentration of the agent to the ratio of 1: 5. The means described in Example 2 is suitable for handling molds of medium complexity.

The release agent and lubricant according to Example 5 was successful for treating very complicated casting molds Pas water dilution ratio used varied between 1: 7 to 1: 15o Good cooling effects were achieved through the lower thermal stress on the material Molded insert and, as a result, a longer service life of the same. Γ-as remedy is for treating complex ones Casting molds suitable for casting iron alloys.

The release agent and lubricant according to Examples 4, 5, 6 and 7 are of pasty consistency, and be applied to the mold with a brush or _o hand brush "In addition, the agents according to Examples 6 and 7 were applied after dilution with special fuel and with compressed air spray gun The agents described in Examples 6 and 7 showed a higher cooling effect in a concentrated state than after dilution o The separating agents and lubricants according to Example

len 5 and 6 are therefore for molds with average The agents according to Examples 4 and 7 are preferably used for treatment of the casting molds with areas that are extremely exposed to heat can be used.

Claims (1)

PATENT LAWYERS DR. ING. E. HOFFMANN (1930-1976). DiPL.-ING.W. VAN. DR.RER. NAT. K. HOFFMANN · Dl PL.-I NG. W. LEH N DIPL. -ING. K. FOCHSLE. DR. RER. NAT. B. HANSEN ARABELLASTRASSE 4 D-8000 MO NCH EN 81. TELEPHONE (08?) 911087. TELEX 05-29619 (PATHE) 35 941 o / to Vyzkumny ustav keramiky, Plzeri / CSSR RELEASE AGENTS AND LUBRICANTS FOR TREATMENT OF CASTING FORMS, IN PARTICULAR FOR DIE CASTING OF IRON ALLOYS Claim Release agents and lubricants for treating casting molds, especially in the die casting of iron alloys, containing very fine-grained graphite in one Amount from 0.5 to 50 parts by weight, possibly finely chopped Aluminum powder in an amount of 0.05 to 15 parts by weight or lithium aluminum hydride in an amount of 0.05 to 10 parts by weight or a mixture thereof, in a hydrocarbon or aqueous medium, characterized in that it is also an oxide of iron, tungsten, Vanadium, bismuth, zirconium or titanium respectively Contains mixture of at least two of these oxides in an amount of 0.5 to 10 parts by weight.