JPS60158943A - Production of casting mold - Google Patents

Abstract

PURPOSE:To increase initial casting mold strength by blowing gaseous or aerosol-like sulfur dioxide to a sand mold formed by adding an acid curable resin, peroxide and prescribed org. compds. or natural fats and oils to a refractory granular material and kneading the mixture. CONSTITUTION:Gaseous or aerosol-like sulfur dioxide is blown to a sand mold formed by adding an acid curable resin and peroxide as well as 1 or >=2 kinds of the following compds. or the mixture composed thereof to a refractory granular material in the stage of use without prior mixing and kneading the mixture thereby manufacturing a casting mold. The above-mentioned compds. are org. compounds such as prescribed ether, ketone, aldehyde, aliphat. hydrocarbon, arom. hydrocarbon or natural animal and vegetable fats and oils.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a mold. More specifically, a mixture of acid-curable resin, peroxide, ethers, ketones, aldehydes, aliphatic hydrocarbons, aromatic hydrocarbons, etc., or natural animal and vegetable oils and fats is added and kneaded to the fire-resistant granular material. The present invention relates to a mold manufacturing method in which gaseous or aerosol sulfur dioxide is injected into a molded sand mold to increase initial mold strength and improve production rate.

Conventionally, when manufacturing cores and main molds at foundries, mold manufacturing using organic self-hardening binders has various advantages such as reduction of industrial waste pollution, rationalization of productivity, and speed. Law,
It has come to be widely used as an alternative to manufacturing methods that use inorganic binders such as water glass and cement.

However, the conventional mold manufacturing method using organic self-hardening binders also has some drawbacks. For example, organic self-hardening binders kneaded with granular refractories are self-hardening, so they cannot be filled into molds for the purpose. When molding a mold, it is usually necessary to let it stand for several tens of minutes to several hours to develop hardening strength. On the other hand, since the chemical reaction of the self-hardening components begins from the start of kneading, there is a There is a problem that the cohesive strength is lost and the pot life is limited depending on the work. - Therefore, the organic self-hardening mold method, which requires a long time to manufacture molds and has a limited usable life of kneaded sand, is not suitable for fields requiring medium to large quantities of mold production.

Conventionally, these applications include the Four-Jung method, in which phenolic resin is heat-cured by covering fire-resistant aggregate, and the hot box method, in which furan-based resins are used.
In recent years, energy-saving and productivity-improving methods such as rounding and cold box methods, in which gaseous or aerosol substances are injected into sand molds to instantaneously manufacture molds, have been put into practical use in these fields. .

One of the cold box methods is the urethane-based cold box method, which uses organic polyisocyanate and polyol-type resin as a binder for the mold, and injects aerosol-like tertiary amine to harden the II# mold. However, this method has drawbacks such as poor disintegration of casting sand during casting production, and the tendency to cause casting defects such as sand trapping, scooping, pinholes, and soot defects.

Instead, there is an ``acid-curing cold box method'' (Patent No. 80771116) in which acid-curing resins such as furan-based, phenol-based, and urea-based resins are cured by blowing gaseous or aerosol sulfur dioxide into the presence of an oxidizing agent. ) has been rapidly attracting attention in recent years as a method to solve the drawbacks of the urethane-based cold box method.

The present invention relates to an improvement in the acid-curing cold box method. In other words, when manufacturing using the cold box method in the mold production field where continuous molding is performed in medium to large quantities,
After the kneaded refractory granules are filled into a mold, they must be removed from the mold using mechanical means within several minutes, preferably within one minute. Conventional molds made using only acid-curing resin and peroxide do not have sufficient initial strength after 30 seconds.
Partial damage was observed, as well as poor filling of the mold.

As a result of intensive research, the present inventors have discovered that in order to further improve mold productivity, ethers, ketones, and aldehydes are added to the refractory granular material as a manufacturing method to improve the initial strength within 1 minute after molding. , one or more compounds such as aliphatic hydrocarbons and aromatic hydrocarbons, or one of natural animal and vegetable oils and fats, etc.
After adding a mixture of at least 1 species and stirring and kneading, an acid-curing resin and peroxide are added and kneaded, or an acid-curing resin is added to the fire-resistant granular material, and after mixing, ethers, ketones, aldehydes, etc. one or more compounds such as aliphatic hydrocarbons, aromatic hydrocarbons, etc., or one of natural animal and vegetable oils and fats, etc.
The present invention has discovered a method for manufacturing a fire-resistant granular material by adding seeds or a mixture of two or more kinds, further adding peroxide, kneading, and blowing gaseous or aerosol sulfur dioxide. The acid-curing resin, peroxide, and one or more of the following compounds or mixtures a) to 1) are added at the time of use without pre-mixing, and the mixture is kneaded and molded into a sand mold. This relates to a method for manufacturing a mold, which is characterized by injecting sulfur dioxide in the form of an aerosol.

a) General formula R, -0-gu, R1-0-R2 or R,7C
Compound represented by HO (R and R2 have 2 to 2 carbon atoms)
8 saturated or unsaturated aliphatic hydrocarbon group) is an aliphatic hydrocarbon group having 18 or less carbon atoms) Δ c) The substituent attached to the Hensen ring is one or two of each of a methoxy group, an aldehyde group, or a nitro group. Aromatic compounds containing 2 or more carbon atoms or 2 or more types, or 2 or more types including hydroxyl groups d) Aliphatic hydrocarbons containing 5 to 12 carbon atoms e) Oxygen atoms in a 5- or 6-membered ring A compound having one or more aldehyde groups in the 7-ring ring f) A compound represented by the general formula R1-Coo-R2 (R,
and R2 is an aliphatic hydrocarbon group having 18 or less carbon atoms, however, one of them may be hydrogen) (2) is an aliphatic hydrocarbon group having 8 or less carbon atoms) 1) Compound represented by the general formula R1-Coo -R2-000-R, (R□, R2 and R5 are aliphatic hydrocarbon groups having 6 or less carbon atoms) j) General formula R, -Coo -R2-0 Compound represented by -R (R, excitation group) and R3 is an aliphatic hydrocarbon or aromatic hydrocarbon group having 6 or less carbon atoms) 1) Natural animal and vegetable oil or fat or natural resin combination ← number key + In the present invention, the above a) to 1) are added and kneaded into the refractory granular material or the refractory granular material coated with the acid-curable resin.
Specifically, the following compounds or mixtures can be used. Styrene, divinylbenzene, toluene,
Xylene, dibutyl ketone, methyl ethyl ketone, tri-n-butyl phosphite, n-butyl acrylate, n-butyl methacrylate, allyl methacrylate.

Trimethylolpropane triacrylate, dipropyl ether, inbutyl vinyl ether, anisole, allyl ether, #-1 Furan, butyl cellosolve acetate, vinyl acrylate, allyl acetone, mesityl oxide, caprone, p-
anisaldehyde, benzaldehyde, furfural,
1,4 dioxane, n-hexyl formate, n-butyl acetate, hexanesyl acetate, n-butyl propionate, methyl coconut, methyl oleate, propylene glycol diacetate, n-hexane, isoprene, n-to butane,
and mustard oil, turpentine oil, crude tall oil, etc., and one or more of these are 0.05% for the refractory granular material.
A composition in which peroxide is added and kneaded to 96 to 2% by weight, preferably 0.1% to 1M, is a composition in which the compounds or mixtures of a) to 1) above are used. Compared to those that are not added and kneaded, it has better filling properties into molds and further improves the initial strength of the hardened mold.

The reason for this is not clear in detail, but it probably acts on the composition interface, i.e., the solid-liquid, liquid-liquid interface, making it easier to penetrate and diffuse particles and imparting physical dispersibility. It is assumed that this will be done. At the same time, it is presumed to have the effect of promoting the chemical reaction between sulfur dioxide gas and peroxide.

The acid-curable resin used in the present invention can be any resin that can be cured using an acid as a curing catalyst, and is generally made by formalin polycondensation of one or more of furan, urea, phenol, and melamine. or a mixture of two or more of these polycondensates. As the refractory granular material, essentially any refractory particles for casting such as silica sand, zircon, chromite, alumina, oripin sand with a high silica content can be used. As peroxides, organic peroxides such as ketone, diacyl and dialkyl peroxides and inorganic peroxides such as hydrogen peroxide can be used alone or in combination of two or more. The amount of peroxide used to carry these acid-curing resins can be within the range of amounts conventionally used.

EXAMPLES Below, the present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited thereto.

Example 1 of the compounds or mixtures shown in Table 1 in Flattery Sand (Australian) 20001, which is a refractory granular material.
Add the seeds and mix with a kitchen mixer for 1 minute, then
Furanurea formalin resin 209 was added and the mixture was stirred and kneaded for 1 minute. Methyl ethyl ketone peroxide 82 containing 10% active oxygen was added to this, and the mixture was further stirred and kneaded for 1 minute.

Place the mixed sample into a molding frame (25X25X250)
After filling with a core shooter (manufactured by Shinra Kogyo Co., Ltd.), sulfur dioxide gas was injected to form a mold.

To evaluate the filling properties and initial bending strength of the kneaded sand, the weight of the mold after molding and the bending strength 30 seconds after the start of sulfur dioxide gas injection were measured.

The values shown in Table 1 are the mold weight and initial bending strength (blank) Th when the exemplified compound or mixture is not added.
It is expressed as a ratio of 100.

As shown in Table 1, compared to the blank, the mold filling density of the examples of the present invention is improved by 5% to 2% by weight.
696 increases, and the initial strength also increases by 10% to 9
The increase was 5%, which confirms the usefulness of the production method of the present invention.

Applicant's agent Kaoru Furutani

Claims (1)

[Scope of Claims] 1. Adding one or more of the following compounds or mixtures of acid-curable resin, peroxide, and the following a) to 1) to a fire-resistant granular material at the time of use without mixing them in advance. A method for manufacturing a mold, which comprises blowing gaseous or aerosol sulfur dioxide into a kneaded and molded sand mold. a) General formula R1-0-R2, R, -0-R, or R, -
Compound n represented by GHQ (R1 and horse have 1 to 1 carbon atoms)
8 saturated or unsaturated aliphatic hydrocarbon group) C) The substituent attached to the benzene ring is one or more of each of a methoxy group, an aldehyde group, or a nitro group, two or more types of Fi, or 2 containing a hydroxyl group. d) Aliphatic hydrocarbons having 5 to 12 carbon atoms; e) Heterocyclic compounds having one or more oxygen atoms in the five- or six-membered ring; or aldehyde groups on the furan ring. Compounds having 1 or more f) Compounds represented by the general formula R□-'aOo-R2 (H and R2 are aliphatic hydrocarbon groups having 18 or less carbon atoms; however, one of them may be hydrogen) having 8 or less atoms. aliphatic hydrocarbon group) is an unsaturated aliphatic hydrocarbon group having 8 or less carbon atoms) X (R1, R2 and R3 are aliphatic hydrocarbon groups having 6 or less carbon atoms) j) General formula R1-Coo -R , -0-R, (R,, R2 and R5 are aliphatic hydrocarbon groups having 4 or less carbon atoms) R2 and R5 are aliphatic hydrocarbon groups or aromatic hydrocarbon groups having 6 or less carbon atoms ) 1) Natural animal and vegetable oil or fat or natural resin 2 The amount of the compound or mixture of a) to 1) used is O,OS in an amount of approximately 2.0% by weight based on the fire-resistant granular material, Claim 1 Method for manufacturing the mold described in Section 1. 3. First, one or more of the compounds or mixtures of a) to 1) are added to the refractory granular material, stirred and kneaded, and then an acid-curable resin and a peroxide are added and kneaded to form a gas or aerosol. A method for manufacturing a mold according to claim 1, wherein sulfur dioxide is blown into the mold. 4 After adding and kneading the acid-curing resin to the fire-resistant granular material,
The mold according to claim 1, in which one or more of the compounds or mixtures of a) to 1) are added, further peroxide is added and kneaded, and gaseous or aerosol sulfur dioxide is blown into the mold. Production method.