JPH0620581B2 - 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 aqueous 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 that heat-cures a novolac-type phenol resin as a binder, or a hot-box method that heat-cures a liquid phenol resin or furan resin is generally used. Has been used. These are all 200-300
Usually, it is baked and hardened at a temperature of 0 ° C., which causes various problems such as energy consumption, hardening time, mold distortion, defective dimension of casting due to deformation, and working environment.

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 cured with a tertiary amine as a catalyst. However, in the urethane cold box method, even when the granular refractory mixture to which the polyol and polyisocyanate are added is left standing, the curing reaction gradually proceeds, and the usable time 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 to mold a mold.

[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.

[Means for solving problems]

Under such circumstances, the inventors of the present invention have conducted intensive studies and as a result, have come to invent a peroxide composition for a curable mold, which is inexpensive, highly safe, and excellent in performance.

That is, the present invention is a peroxide used as an oxidizer when a mold is produced by adding an acid-curable resin and an oxidizer and injecting gaseous or aerosol sulfur dioxide into a granular refractory aggregate mixture. A water-containing ketone peroxide composition comprising a dilution stabilizer, which is solubilized with at least one solubilizing agent selected from the group consisting of water-soluble ether compounds and water-soluble ester compounds and uniformly prepared The present invention relates to a peroxide composition for a template, characterized in that

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 water tank 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.

According to the present invention, the peroxide composition does not include a solvent that serves as a curing retarder for improving these problems and homogenizing, does not contain a diluent stabilizer, and contains water. It has excellent performance as an oxidizing agent, does not require a complicated manufacturing process, is inexpensive, and is excellent in safety against fire, etc. due to its water content, and provides practically satisfactory results. Is.

As a preferred method for producing the hydrous ketone peroxide composition of the present invention, at least one kind of an aliphatic ketone having 3 to 8 carbon atoms or an alicyclic ketone having 6 to 10 carbon atoms is subjected to acid-catalyzed hydrogen peroxide. This is a method of solubilizing a ketone peroxide formed by oxidation with water and a dilution stabilizer with a solubilizing agent without separating water during or after production.

The solubilizing agent used in the present invention is at least one selected from the group consisting of water-soluble ether compounds and water-soluble ester compounds, and examples thereof include diokian, tetrahydrofuran, phosphoric acid ester, acetic acid ester and the like.

As the dilution stabilizer used in the present invention, the following [I]-
One or more compounds represented by [V] may be mentioned.

[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 an alkyl group in which all the sums of carbon numbers of R ₁ are n to 60,
It is an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an aralkyl group, or a halogen, alkoxy, acyloxy or alkoxycarbonyl substitution product thereof. ) [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] Saturated or unsaturated fatty acid having 12 to 24 carbon atoms, furfuryl alcohol, phenolic compound, aliphatic or aromatic Aldehyde compounds, furfuryl alcohol / formalin polycondensates, phenolic compounds / formalin polycondensates, urea / formalin polycondensates, melamine / formalin condensates.

The proportion of each component in the peroxide composition of the present invention is: ketone peroxide 35-60 wt% water 5-40 wt% dilution stabilizer 10-60 wt% solubilizer 5-40 wt% Requires.

When the proportion of ketone peroxide exceeds 60% by weight, the concentration of active oxygen is increased, the tendency of spontaneous decomposition is accelerated, and the danger is significantly increased. When the proportion of ketone peroxide is less than 35% by weight, when the refractory granular aggregate and the ketone peroxide composition are kneaded, some of the ketone peroxide is decomposed by impurities present in the refractory granular aggregate. However, the absolute amount of sulfur dioxide as an oxidant is insufficient, and the curing speed is rapidly reduced. Further, even if the proportion of the dilution stabilizer is less than 10% by weight, the ketone peroxide becomes unstable and the tendency of spontaneous decomposition is accelerated, and the risk is significantly increased, while it is necessary to use more than 60% by weight. Absent. If the water content is less than 5% by weight, the safety improving effect is small, and if the water content exceeds 40% by weight, water is essentially a retarder for this curing reaction, and the curing rate becomes so slow that it cannot be practically used. If the solubilizing agent is less than 5% by weight, there is no solubilizing effect. Further, even if the solubilizing agent is used in an amount of more than 60% by weight, the solubilizing effect does not change, and on the contrary, the ketone peroxide becomes unstable and the tendency of spontaneous decomposition increases.

In addition to the above essential components, the composition of the present invention may contain a nonionic or anionic 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 and their condensates or mixtures thereof, and these resins are usually 5 to 20 parts by weight per 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 1-4 and Comparative Examples 1-2 Ketone peroxide 50% by weight, dilution stabilizer 20% by weight, solubilizer 10% by weight, water content 20% by weight of the present invention and comparative water-containing ketone par In order to evaluate the performance of the oxide composition as an oxidizing agent in the acid-curable cold box method, a mold was molded and the mechanical properties of the mold were investigated.

A mixture of 12 parts by weight of furan resin and 5 parts by weight of a peroxide composition was added to 1,000 parts by weight of Australian flattery silica sand and kneaded, and the mixture was filled in a 25 × 25 × 250 m / m mold and blown with gaseous sulfur dioxide. The mold was molded by washing with compressed air. The bending strength of the mold was measured over time after molding.
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 (3)

[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. And a hydrous ketone peroxide composition containing a dilution stabilizer homogeneously prepared by solubilizing it with at least one solubilizing agent selected from the group consisting of water-soluble ether compounds and water-soluble ester compounds. The ratio of each component is 35-60% by weight of ketone peroxide 5-40% by weight of water Diluting stabilizer 10-60% by weight Solubilizing agent 5-40% by weight Composition. 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. 3. The composition according to claim 1, wherein the dilution stabilizer is one or more compounds represented by the following [I] to [V]. [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, all R ₁ may be the same or different, alkyl group of the sum of all the number of carbon atoms of R ₁ is N～60, alkenyl group, alkynyl group, cycloalkyl group, aryl group, aralkyl A group, or a halogen, alkoxy, acyloxy or alkoxycarbonyl substitution product thereof. ) [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. Well, alkyl groups, alkenyl groups, alkynyl groups, all of which have 1 to 20 carbon atoms,
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. 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] Saturated or unsaturated fatty acid having 12 to 24 carbon atoms, furfuryl alcohol, phenolic compound, aliphatic or aromatic Aldehyde compounds, furfuryl alcohol / formalin polycondensates, phenolic compounds / formalin polycondensates, urea / formalin polycondensates, melamine / formalin condensates.