JPS5820344A - Powdered coating agent - Google Patents

Abstract

PURPOSE:To prevent the scattering of powder during handling of powdered coating agent and to improve working environment by mixing liq. of specific properties at a specific amt. with a mixture of a refractory base material and a binder. CONSTITUTION:A material which has >=100 deg.C b.p. and is liquid at ordinary temp. is mixed with a mixture of a general known refractory base material and a binder at 1.5-8.0wt% ratio basing on the weight of the mixtue. The reason for specifying the mixing ratio lies in that if the amt. of said material to be used exceeds 8.0wt%, the powdered coating agent causes caking during storage and loses fluid characteristics as powder. If the amt. of the addition is below 1.5wt%, sufficient characteristics are not provided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder coating agent used in the production of molds, and more particularly to a powder coating agent that significantly improves the work load during use. It is generally known that it is packaged in the form of a paste, a paste, and a powder. The latter (powder form) has many advantages over the former, such as disposal of empty containers, cost reduction, and the ability to manage dangerous substances as a container, and is expected to be used more frequently in the future. However, when working on the ninth wheel,
In particular, dispersion media (water, alcohol, etc.) and oia in the field
There is a disadvantage that dust is generated during kneading, which significantly worsens the working environment.

In order to overcome this drawback, the present inventors have devised a method of adding a liquid to this powder. In the foundry industry, common sense suggests that if a liquid is added to the lubricant powder, the lubricant powder will sag during storage due to load, form lumps, and become unusable. Are you being watched?)
The nine volatile powder lubricants include methanol, ethanol,
If liquids other than those normally used as dispersants, such as lower alcohols such as imp-4-panol, are included, defects such as cracking or cracking after processing may occur during casting production. However, the present inventors believe that there is no other way than adding a liquid to eliminate the above-mentioned drawbacks, and the inventors believe that the method of adding liquid is the only way to eliminate the above-mentioned drawbacks. Ih that eliminates the drawback of dust generation, which is the problem with topical lubricants.
Obtaining an IM agent As a result of intensive research, it was found that the desired purpose was achieved by mixing a certain amount of a casing with certain properties into a powdered mixture of a fireproof base material and a binder. Ell discovered that a mold coating agent could be obtained and completed the present invention.
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That is, in the present invention, 1.5 to 8.0% by weight of a substance having a boiling point of 100° C. or more and being liquid at room temperature is mixed into a powder mixture of a fireproof base material and a binder. The present invention provides a powder coating agent consisting of:

In this publication, a substance with a boiling point of 100°C or higher that is liquid at room temperature refers to a substance that has a boiling point of 100°C or higher and is liquid at the temperature of use, and even if it is an inorganic substance, it is an organic substance. However, preferred examples include water, ethylene glycol, glycerin, diethylene glycol, and propylene glycol. These may be used alone or in mixtures of two or more together with other substances. When used in conjunction with other substances, examples include aqueous emulsions of polymers, honey water, clay water, and the like.

Commercially available powder coating agents for ceramics contain about 0.5 to 1.0 weight of water, but at this level they are not effective in preventing dust scattering. Refers to known fire-resistant base materials used for molding agents, such as zircon, silica powder, graphite a
t etc. can be mentioned.

Further, as the binder in the present invention, a generally known binder used for powder coating agents is used. Examples include dextrin, bentonite 1, phenol resin, and rosin.

In the present invention, the amount of the substance having a boiling point of 100°C or higher and exhibiting a liquid state at room temperature is 1.5 to 8.0% by weight, preferably 2.0% by weight, based on the mixture of fireproof base material and binder. ~7.
0 weight. If the amount used exceeds 8% by weight, the mold coating agent will cause caking during storage, resulting in 0R11J as a powder.
In addition, in the case of alcohol-based mold coating agent (41), undesirable effects such as hardness on the surface of the casting during casting occur. Further, the amount of the above substance added is 1.
If the weight is less than 5 -, the characteristics of the present invention cannot be fully exhibited.

As described above, by using the powder coating agent of the present invention, it is possible to suppress the generation of dust when handling the powder coating agent, and greatly contribute to improving the working environment and health management of workers.

Next, the content of the present invention will be specifically explained with reference to the following examples. Examples 1 to 7 Each powder is blended as follows.Mixture: 925 parts of zircon, 45 parts of silica powder, phosphorous graphite sO parts, and 5 parts of dextrin are uniformly mixed. mixed with.

Mixture 3: Novolac resin powder S, rh @ added instead of dextrin in Mixture M 0 Mixture 0: Homogeneous mixture O of 70 parts of phosphorous graphite, 30 parts of silica powder, and 3 parts of -Tough to the above mixtures M to O Mix various additives as shown in Table 1 and stir efficiently for 5 minutes to obtain an apparently homogeneous mixture. The fluidity was also good.

Mata, evaluated the disintegration after 5 days of pressurization (1,712/CI + 1.40℃), and the results are shown in Table 1. For Example S, diluted with methanol, applied to the mold, and ignited. Dry nine. At this flange, a bracket with a unit weight of 50 - (material: 10
As a result of casting at -22% pouring temperature of 11,580℃), a cast product with a clean casting surface and no burning was obtained.

9. According to Example 7, water was added to this to make a slurry, and when it was applied to the flange and poured after drying, the unit weight was 2.
．． Goo~'s Kokum (Material: 0-SO, pouring temperature: 138
(0°C), there was no burning and the casting surface was clear. Both ofll Examples 3 and 7 had no defects after processing and were sound products.

Comparative Example 1 When 6 parts of water was added to 150 parts of a mixture, no scattering of fine powder was observed, but caking occurred under pressure and the powder lacked smooth fluidity.

Comparative Example 2 Although 0.05 parts of ethylene glycol was added to 150 parts of the mixture to form a uniform powder that was well agitated, it was not possible to efficiently suppress dust scattering during handling.

Claims (1)

[Claims] A powder coating agent made by mixing 1.5 to 8.0% by weight of a substance with a boiling point of 100°C or higher and a liquid state at room temperature to a mixture of a fireproof base material and a binder.