JPS6182946A - Peroxide composition for casting mold - Google Patents

Abstract

PURPOSE:To provide a peroxide compsn. for a casting mold which is inexpensive, safe and functionally excellent by using a ketone peroxide compsn. contg. a specific dilution stabilizing agent in the stage of adding and kneading an oxidizing resin and peroxide compsn. to granular refractory aggregate, molding a sand mold, adding SO2 to such sand mold and molding the casting mold. CONSTITUTION:Gaseous or aersol-like SO2 is introduced to the granular refrac tory aggregate (e.g.; silica sand consisting essentially of quartz) added with an acid curale resin (e.g.; furan resin) and oxidizing agent. The ketone peroxide compsn. (e.g.; methyl ethyl ketone peroxide) contg. >=1 kinds of the following dilution stabilizing agents is used as the peroxide compsn. for the casting mold to be used in this case: The above-mentioned dilution stabilizing agent is >=1 kinds of the compd. expressed by formula I, II, aliphat. hydrocarbon of 5-18C, etc. In this case 0.5-3pts.wt. thermosetting resin and 0.1-2pts.wt. peroxide compsn. are usually used in 100pts.wt. the granular refractory aggregate. The peroxide compsn. contg. 15-60wt% dilution stabilizing agent is more preferable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention involves adding and kneading an acid-curing resin and a peroxide composition to a granular refractory material, and applying gaseous or aerosol sulfur dioxide to a molded sand mold. The present invention relates to a curable mold composition used when molding a mold by adding a peroxide, and particularly relates to an improvement of a peroxide composition.

[Conventional technology and problems]

Traditionally, when manufacturing cores and main molds at foundries, we have focused on reducing industrial waste pollution, rationalizing productivity, improving casting quality,
Due to various other advantages, mold manufacturing methods using furan self-hardening binders have come to be widely used in place of manufacturing methods using inorganic binders such as water glass and cement.

However, mold manufacturing methods using furan self-hardening binders also have some drawbacks. One of them is that the curing time is long, and it takes about 1 minute to several hours to manufacture a mold, making it unsuitable for high-speed mold manufacturing.

Conventionally, in applications for manufacturing molds at high speed, a cloning method has been used in which so-called coated sand, which is a granular refractory material coated with a phenol novolac resin, is thermally cured.

However, in order to save energy, speed up mold production, and streamline the mold manufacturing process, the casting industry is seriously considering introducing the so-called cold box method, which involves gas curing at room temperature, as an alternative method.

Currently, cold box methods include the so-called furan cold box method, in which acid-curable resins such as furan resin are cured with sulfur dioxide using peroxide as an oxidizing agent, and the so-called furan cold box method, in which acid-curable resins such as furan resin are cured using sulfur dioxide as an oxidizing agent, and polyol and polyisocyanate are cured using an aerosol of tertiary amine as a catalyst. There is a urethane cold box method that cures as
The Furan cold box method, which has been proven to have good results in the production of castings due to its self-hardening properties, has recently been rapidly attracting attention.

However, the Fran cold box method also has some points to be improved, among which are improvements in cost and safety due to peroxides. Currently, commonly used peroxides include compositions containing ketone peroxides such as methyl ethyl ketone peroxide as a main component, or compositions containing aromatic hydroperoxides such as cumene hydroperoxide as a main component. All of these peroxide compositions are expensive and there is a need to further improve their safety.

Hydrogen peroxide is an inexpensive and highly safe peroxide, but it has not been put to practical use because it decomposes due to impurities in the granular refractory material, has a short useful life as a kneaded product, and has low mold strength.

Hydrous ketone peroxides are also commercially available, but they can be used to react acid-curing resins using polyols such as glycerin, cellosolve, nitrogen-containing water-soluble compounds such as pyrrolidone, etc. as homogenizing agents that also serve as dilution stabilization. is delayed and is practically unusable.

[Means for solving problems]

As a result of intensive research to solve the above-mentioned conventional problems, the present inventors have developed an organic peroxide composition that is inexpensive, highly safe, and has sufficient performance as a peroxide for Francold boxes. Heading The present invention has been arrived at.

That is, the present invention is a peroxide composition that is used when manufacturing a mold by introducing gaseous or aerosol sulfur dioxide into a granular refractory aggregate mixture to which an acid-curable resin and an oxidizing agent are added. The present invention relates to a peroxide composition for molds, characterized in that it is a ketone peroxide composition containing at least one kind selected from the group consisting of the following (al to (g)) as a dilution stabilizer: .

(al A compound represented by the general formula R+ORz (wherein R1 and R2 are each a saturated or unsaturated aliphatic hydrocarbon group having 1 to 8 carbon atoms).

(Formula Nakamura and R4 are each an aliphatic hydrocarbon group having 18 or less carbon atoms or a hydrogen atom).

(An aromatic compound in which the substituent attached to the C1 benzene ring is one, two or more, or two or more types of each of a methoxy group, an aldehyde group, or a nitro group.

(d) Aliphatic hydrocarbons having 5 to 18 carbon atoms.

fe) Saturated or unsaturated fatty acids of 5 to 22 carbon atoms vi.

(fl　Alicyclic carboxylic acid having 5 to 40 carbon atoms.

(g) General formula Rs COOR, (Rs is a hydrogen atom or a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, R6 is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms) The compound shown in

The dilution stabilizer used in the present invention is a homogenizing agent that also serves as dilution stabilization, and does not delay the curing reaction of the acid-curable resin.

The peroxide composition of the present invention contains a dilution stabilizer from 15 to
It preferably contains 60% by weight, and can further contain 30% by weight or less of water.

As the granular refractory aggregate, silica sand containing quartz as a main component, zircon sand, chromite sand, etc. are used, but the present invention is not limited to these.

Further, as the acid-curable resin, furan resin, phenol resin, urea resin, melamine resin, or a copolymer or mixed resin thereof may be used, but the present invention is not limited to these.

Usually, 100 parts by weight of granular refractory aggregate and 0.00 parts by weight of acid-curing resin.
5 to 3 parts by weight and 0.1 to 2 parts by weight of the peroxide composition are used.

〔Effect of the invention〕

According to the present invention, it is possible to provide a peroxide composition for molds that is inexpensive, safe, and functionally excellent.

[Example] In order to explain the present invention in more detail, the advantages of the present invention will be described below using examples, but the scope of the present invention is not limited by the following examples.

Examples 1 to 17, Comparative Examples 1 to 2 As peroxide compositions, methyl ethyl ketone peroxide compositions containing the dilution stabilizer according to the present invention shown in Table 1 and conventionally commercially available ones were used for comparison. A mold was formed.

In addition, the active oxygen content of these peroxide compositions was adjusted to 1.0% to keep the effective content constant.

The mold is made of Australian flattery silica sand.
0 parts by weight, 12 parts by weight of furan resin, and 4 parts by weight of peroxide composition were added and kneaded in a 25 x 25 x 2 mixture.
Blow it into a 50m/m formwork with pressurized air to fill it.
Next, sulfur dioxide gas was injected into the mold filled with the mixture, and the mold was washed with clean air to form a mold. The bending strength of the molded mold was measured over time, and the oxidizing ability of the peroxide composition was investigated.

The results are shown in Table 1.

Table 1 Example 1 Σ(~25, Comparative Examples 3-4 Aust → Su7 produced flattery-4+1. Sand 1, (1+
1 (A hydrous methyl ethyl ketone peroxide composition containing 1 weight part, 5 weight parts of furan lubricant I, 10% active oxygen, 15% water, and 25% dilution stabilizer shown in Table 2) 5
Add and mix parts by weight! T! Pour the mixture 25X
A mold of 25 x 250 m/m was filled by blowing with pressurized air, and then sulfur dioxide scum was injected into the mold filled with the mixture, and then washed with clean air to form the mold. The bending strength of the molded mold was measured over time, and the oxidizing ability of the peroxide composition was investigated.

The results are shown in Table 2.

Table 2 Examples 26 to 31, Comparative Examples 5 to 6 Enshu washing No. 6 silica sand 1,000 heavy weight part, furan resin 1
A mixture obtained by adding and kneading 6 parts by weight of a hydrous methyl ethyl ketone peroxide composition containing 10% active oxygen, 20% water, and 25% dilution stabilizer shown in Table 3. A mold of 25 x 25 x 250 m/m was filled by blowing with pressurized air, and then sulfur dioxide gas was injected into the mold filled with the mixture, and then washed with clean air and the mold was formed. . The bending strength of the molded mold was measured over time, and the oxidizing ability of the peroxide composition was determined to be 318 points.

The results are shown in Table 3.

Table 3

Claims (1)

[Claims] 1. A peroxide composition used when manufacturing a mold by introducing gaseous or aerosol sulfur dioxide into a granular refractory aggregate mixture containing an acid-curable resin and an oxidizing agent. A peroxide composition for molds, characterized in that it is a ketone peroxide composition containing at least one kind selected from the group consisting of the following (a) to (g) as a dilution stabilizer. (a) General formula R_1-O-R_2 (in the formula R_1 and R_
2 is a compound represented by a saturated or unsaturated aliphatic hydrocarbon group each having 1 to 8 carbon atoms. (b) A compound represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_3 and R_4 are each an aliphatic hydrocarbon group or a hydrogen atom having 18 or less carbon atoms). (c) An aromatic compound in which the substituent attached to the benzene ring is one, two or more, or two or more types of each of a methoxy group, an aldehyde group, or a nitro group. (d) Aliphatic hydrocarbons having 5 to 18 carbon atoms. (e) Saturated or unsaturated fatty acids having 5 to 22 carbon atoms. (f) Alicyclic carboxylic acid having 5 to 40 carbon atoms. (g) General formula R_5-COO-R_6 (R_5 is a hydrogen atom or a saturated or unsaturated aliphatic hydrocarbon group having 1 to 22 carbon atoms, R_6 is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms) A compound represented by a group). 2. The peroxide composition for molds according to claim 1, which contains 15 to 60% by weight of a dilution stabilizer.