JPH0620584B2 - Peroxide composition for mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an oxidizing agent used when sulfur dioxide is added to a granular refractory aggregate mixture containing an acid-curable resin and an oxidizing agent to form a mold. It is about. More specifically,
The present invention relates to a specific organic peroxide composition used as an oxidizing agent for the acid-curable mold.

[Conventional technology]

Conventionally, for high-speed mold production applications typified by automobile castings, a cloning method in which a novolac type phenolic resin is used as a binder and heat curing, or a hot box method in which a liquid phenolic resin or furan resin is heat cured is generally used. Has been used. All of these are 200-300 ℃
It is usual to bake and harden it, and as a result, there are various problems such as energy consumption, hardening time, mold distortion, dimensional defect of casting due to deformation, working environment and the like.

In recent years, a so-called cold box method, in which a gaseous or aerosol substance is blown at room temperature to form a mold, has been drawing attention and spreading as a molding method for improving these difficulties.

As a cold box method, there is a urethane cold box method in which a polyol compound and polyisocyanate are used as a binder and a tertiary amine is used as a catalyst for curing. However, in the urethane cold box method, even when the granular additive mixture containing the polyol and polyisocyanate is left to stand, the curing reaction gradually proceeds, and the pot life of the mixture is short, or soot defects, gas defects, etc. There are problems such as many casting defects. At present, another cold box method is an acid-curable cold box method in which an acid-curable resin and an oxidizing agent are added to a granular refractory material, and then sulfur dioxide is blown into the mold to mold it.

[Problems to be solved by the invention]

In this method, the curing reaction does not proceed unless the particulate refractory mixture and sulfur dioxide come into contact with each other, so that the mixture has a long pot life, and an acid-curable resin excellent in heat resistance represented by a furan resin is used as a binder. Therefore, there are advantages such as less casting defects. However, this acid-curable cold box method requires the use of an expensive organic peroxide as an oxidant, and there is a concern that the stability of the organic peroxide is uncertain. Oxide is required.

In addition, hydrogen peroxide solution is mentioned as an inexpensive and highly safe peroxide, but the hydrogen peroxide solution is easily decomposed by the alkali content, metal oxide, and other impurities contained in the granular refractory aggregate, The usable time after mixing of the mixture obtained by adding the resin and the peroxide to the refractory aggregate and kneading, the so-called usable time is short and practically unusable.

Further, when a main mold or the like is molded by this acid-curable cold box method and white smoke is generated when pouring molten metal, a peroxide with a small amount of white smoke and good environment is required.

[Means for solving problems]

Under such circumstances, as a result of intensive studies by the present inventors, the invention of a peroxide composition for a curable mold, which is inexpensive, highly safe, and excellent in performance, and particularly which causes little white smoke during pouring of molten metal It came to.

That is, the present invention is a peroxide composition used as an oxidizing agent when a gaseous or aerosol sulfur dioxide is injected into a granular refractory bone agent mixture to which a peroxide resin and an oxidizing agent are added to produce a mold. The ratio of each component is ketone peroxide 20 to 60% by weight water less than 5% by weight 1st dilution stabilizer below 10 to 50% by weight 2nd dilution stabilizer below 5 to 50% by weight Is. The present invention relates to a peroxide composition for a template, which is a ketone peroxide composition diluted with a first dilution stabilizer and a second dilution stabilizer.

First Dilution Stabilizer One or more compounds represented by the following [I] to [XI].

[I]

(In the formula, n is 1 to 3, and when n = 1, X is an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group or aralkyl group having 1 to 20 carbon atoms.

When n = 2, X is an alkylene group having 2 to 20 carbon atoms, an alkenylene group, an alkynylene group, a cycloalkylene group, a phenylene group, an alkylene group, or an alkyl-substituted product thereof.

When n = 3 For n = 1 to 3, R ₁ may be the same or different, and the sum of all carbon atoms of R ₁ is n to 60, an alkenyl group, an alkynyl group, a cycloalkyl group,
Aryl group, aralkyl group, or halogen thereof,
It is an alkoxy, acyloxy or alkoxycarbonyl substitution product. ) [II] (In the formula, m is an integer of 1 to 300.

Y is an alkylene group having 2 to 20 carbon atoms, an alkenylene group, an alkynylene group, a phenylene group or an alkylene group.

R ₂ and R ₃ may be the same or different, and the sum of all carbon atoms is 1 to 20 alkyl group, alkenyl group, alkynyl group,
It is a cycloalkyl group, an aryl group or an aralkyl group. R ₃ further includes a hydrogen atom and an acyl group. ) [III] Glycerin esters (In the formula, R ₄ , R ₅ and R ₆ are a hydrogen atom or an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group or an aralkyl group having a total of 1 to 60 carbon atoms.

However, at least one of R ₄ , R ₅ , and R ₆ is not a hydrogen atom. ) [IV] Phosphorus ester (In the formula, R ₇ , R ₈ and R ₉ are a hydrogen atom, or an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group having 1 to 20 carbon atoms, or a halogen, alkoxy or acyloxy substitution product thereof. However, at least one of R ₇ , R ₈ and R ₉ is not a hydrogen atom.) [V] (In the formula, R ₁₀ and R ₁₁ are an alkyl group, an alkenyl group, or an alkynyl group having 1 to 20 carbon atoms.) [VI] (In the formula, each of R ₁₂ and R ₁₃ is an aliphatic hydrocarbon group having 18 or less carbon atoms or a hydrogen atom.) [VII] Each of the substituents on the benzene ring is a methoxy group, an aldehyde group or a nitro group. Alternatively, two or more or two or more aromatic compounds.

[VIII] An aliphatic hydrocarbon having 5 to 18 carbon atoms.

[IX] Saturated fatty acid having 1 to 22 carbon atoms or 5 to 22 carbon atoms
Unsaturated fatty acids.

[X] An alicyclic carboxylic acid having 5 to 40 carbon atoms.

[XI] Furfuryl alcohol, phenolic compound, aliphatic aldehyde compound, furfuryl alcohol / formalin polycondensate, phenolic compound / formalin polycondensate, urea / formalin polycondensate, melamine / formalin condensate.

Second dilution stabilizer At least one selected from the group consisting of alcohol compounds, ketone compounds and ether compounds.

Usually, a ketone peroxide composition reacts with a hydrogen peroxide solution using a mineral acid such as sulfuric acid as a catalyst, an aliphatic or alicyclic ketone, and an aliphatic or aromatic dibasic acid diester as a carrier agent in a dropping reaction under cooling to react. After completion, the aqueous layer is separated, and the non-aqueous layer is neutralized, washed, dried, and purified to produce a non-aqueous peroxide composition. This product has a complicated manufacturing process and takes man-hours, and when considering the amount of raw material charged, the yield also significantly decreases,
Not only is it expensive, but it is also non-aqueous, which poses a danger.

On the other hand, there are polyhydric alcohols such as glycerin, water-containing homogenized ketone peroxide compositions using nitrogen-containing water-soluble solvents such as N-methyl-2-pyrrolidone as a carrier agent,
These carrier agents serve as a curing retarder for the acid-curable resin and are inexpensive and highly safe, but when used as an oxidizing agent for the acid-curable cold box method, they cause mold curing failure and are practically unusable.

The peroxide composition of the present invention does not contain a solvent that serves as a curing retarder for improving these problems and homogenizing the above problems.
It contains a dilution stabilizer and a second dilution stabilizer, and it has excellent performance as an oxidizing agent for the acid-curable cold box method, does not require a complicated manufacturing process, is inexpensive, and is safe against fire and the like. The excellent properties also provide practically satisfactory results.

As a preferred method for producing the ketone peroxide composition of the present invention, at least one of an aliphatic ketone having 3 to 8 carbon atoms or an alicyclic ketone having 6 to 10 carbon atoms is added to hydrogen peroxide solution under an acid catalyst. It is a method of mixing a ketone peroxide formed by oxidation with the first dilution stabilizer and the second dilution stabilizer.

The proportion of each component in the peroxide composition of the present invention is as follows: ketone peroxide 20 to 60% by weight water less than 5% by weight First dilution stabilizer 10 to 50% by weight Second dilution stabilizer 5 to 50% by weight %.

When the proportion of ketone peroxide is less than 20% by weight, when the refractory granular aggregate and the ketone peroxide composition are kneaded,
Impurities present in the refractory granular aggregate decompose some of the ketone peroxide, resulting in a shortage of the absolute amount of sulfur dioxide as an oxidant and a rapid decrease in the curing rate. On the other hand, when the proportion of ketone peroxide exceeds 60% by weight, the concentration of active oxygen becomes high, the tendency of spontaneous decomposition becomes faster, and the danger is significantly increased. The ketone peroxide composition of the present invention is an anhydrous type, and it is necessary that the water content is less than 5% by weight.
When it is 5% by weight or more, the curing rate becomes slow and the two layers are separated. If the first dilution stabilizer is less than 10% by weight, the ketone peroxide becomes unstable and the tendency of spontaneous decomposition becomes faster.
The risk is significantly increased. On the other hand, it is not necessary to use more than 50% by weight. If the second dilution stabilizer is less than 5% by weight, white smoke will increase during pouring. On the other hand, it is not necessary to use more than 50% by weight.

In addition to the above essential components, the composition of the present invention may contain a nonionic or anionic sea surfactant.

Usually, when molding a mold, zircon sand or chromite sand is used as the granular refractory aggregate in addition to silica sand containing silica as a main component, but the present invention is not particularly limited to this. Examples of the acid-curable resin include furan resin, phenol resin, urea resin, melamine resin or co-condensates or mixtures thereof, and these resins are usually 5 to 20 parts by weight with respect to 1000 parts by weight of the granular refractory aggregate. Part used. The peroxide composition of the present invention is usually used in an amount of 3 to 10 parts by weight based on 1000 parts by weight of aggregate.

〔Example〕

Hereinafter, examples will be described to describe the present invention in more detail, but the scope of the present invention is not limited by these examples.

Examples 1 to 10 and Comparative Examples 1 and 2 To 1000 parts by weight of Australian flattery silica sand, 15 parts by weight of furan resin and 5 parts by weight of the inventive and comparative ketone peroxide compositions (water content 2% by weight) were added. The kneaded mixture was filled in a circular mold (for measuring white smoke, mold weight 60 kg), then sulfur dioxide gas was injected into the mold filled with the mixture, and then the mold was cleaned with clean air. Molded.

Cast the molten metal of about 1420 ℃ into the molded white smoke measuring mold,
The time from when the molten metal was cast until white smoke disappeared was measured. The results are shown in Table 1.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08K 9/04 KCP 7242-4J C08L 101/00

Claims (2)

[Claims] 1. A peroxide composition used as an oxidizing agent when a gaseous or aerosol sulfur dioxide is injected into a granular refractory aggregate mixture containing an acid-curable resin and an oxidizing agent to produce a mold. The proportion of each component is: ketone peroxide 20 to 60% by weight water less than 5% by weight 1st dilution stabilizer 10 to 50% by weight 2nd dilution stabilizer 5 to 50% by weight A certain peroxide composition for a template, which is a ketone peroxide composition diluted with a first dilution stabilizer and a second dilution stabilizer. First Dilution Stabilizer One or more compounds represented by the following [I] to [XI]. [I] (In the formula, n is 1 to 3, and when n = 1, X is an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group or an aralkyl group having 1 to 20 carbon atoms. In the case, X is an alkylene group having 2 to 20 carbon atoms, an alkenylene group, an alkynylene group, a cycloalkylene group, a phenylene group, an alkylene group or an alkyl-substituted product thereof, where n = 3. For n = 1 to 3, R ₁ may be the same or different,
An alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an aralkyl group, or a halogen, alkoxy, acyloxy or alkoxycarbonyl substitution product of these, in which the sum of all carbon atoms of ₁ is n to 60. ) [II] (In the formula, m is an integer of 1 to 300. Y is an alkylene group having 2 to 20 carbon atoms, an alkenylene group, an alkynylene group, a phenylene group or an alalkylene group. R ₂ and R ₃ may be the same or different. Often, it is an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group or an aralkyl group whose sum of carbon atoms is 1 to 20. R ₃ further includes a hydrogen atom and an acyl group. ] Glycerin esters (In the formula, R ₄ , R ₅ and R ₆ are a hydrogen atom or an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group or an aralkyl group having a total of 1 to 60 carbon atoms. At least one of R ₄ , R ₅ and R ₆ is not a hydrogen atom.) [IV] Phosphorus ester (In the formula, R ₇ , R ₈ and R ₉ are a hydrogen atom, or an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group having 1 to 20 carbon atoms, or a halogen, alkoxy or acyloxy substitution product thereof. However, at least one of R ₇ , R ₈ and R ₉ is not a hydrogen atom.) [V] (In the formula, R ₁₀ and R ₁₁ are an alkyl group, an alkenyl group, or an alkynyl group having 1 to 20 carbon atoms.) [VI] (In the formula, each of R ₁₂ and R ₁₃ is an aliphatic hydrocarbon group having 18 or less carbon atoms or a hydrogen atom.) [VII] Each of the substituents on the benzene ring is a methoxy group, an aldehyde group or a nitro group. Alternatively, two or more or two or more aromatic compounds. [VIII] An aliphatic hydrocarbon having 5 to 18 carbon atoms. [IX] Saturated fatty acid having 1 to 22 carbon atoms or 5 to 22 carbon atoms
Unsaturated fatty acids. [X] An alicyclic carboxylic acid having 5 to 40 carbon atoms. [XI] Furfuryl alcohol, phenolic compound, aliphatic aldehyde compound, furfuryl alcohol / formalin polycondensate, phenolic compound / formalin polycondensate, urea / formalin polycondensate, melamine / formalin condensate. Second dilution stabilizer At least one selected from the group consisting of alcohol compounds, ketone compounds and ether compounds. 2. The method according to claim 1, wherein the ketone peroxide is at least one of an aliphatic ketone peroxide having 3 to 8 carbon atoms and an alicyclic ketone peroxide having 6 to 10 carbon atoms. Composition.