CS243356B1 - CoatSolid material refining the surface of metal alloy castings - Google Patents

Abstract

The solution relates to a coating material for softening the surface of castings of metal alloys, water-soluble, not containing quartz and water glass. As components, it contains quartz, water glass, adduct of maleic anhydride to levopimaric acid, concentrated ammonia, demineralized water, or a dye, and the mutual weight ratio of quartz and water glass is 1.5 to 1.7:1 and the mutual weight ratio of the adduct and concentrated ammonia is 2.2 to 2.4:1. The coating material is to be used wherever there is a requirement for high quality of the surface of castings, dimensional accuracy and ease of its equipment, such as in foundry, dentistry, prosthetics, artistic production and elsewhere.

Description

(54) Coating material softening the surface of metal alloy castings The solution relates to a coating material softening the surface of metal alloy castings, water-soluble, not containing quartz and water glass. As components, it contains quartz, water glass, adduct of maleic anhydride to levopimaric acid, concentrated ammonia, demineralized water, or a dye, and the mutual weight ratio of quartz and water glass is 1.5 to 1.7:1 and the mutual weight ratio of the adduct and concentrated ammonia is 2.2 to 2.4:1. The coating material is to be used wherever there is a requirement for high quality of the surface of castings, dimensional accuracy and ease of its equipment, such as in foundry, dentistry, prosthetics, artistic production and elsewhere.

243356 2

The invention relates to a coating material for smoothing the surface of metal alloy castings, water-soluble, not based on quartz and water glass. This coating material is used as a base for common investment materials and has wide applications in foundry, dentistry, prosthetics, artistic production and wherever high demands are placed on the quality of the casting surface, dimensional accuracy and ease of its equipment.

The previously used investment castings /for example, of the Silikau, Expadenta, Gloria Special, Garasin type/ for casting fine structures from metal alloys primarily guarantee sufficient expansion of the mold and thus the required dimensional accuracy of the casting.

However, they do not meet the requirements for high quality of the casting surface and ease of its equipment. To improve this, an ethyl silicate-based coating (Silikan L) was tested, which was applied in a thin layer to the wax model.

After the material had solidified, the model was cast in the usual way into silicone. The required long-term stability of the material, which solidifies spontaneously due to air humidity and moisture in the raw materials during storage, was unsatisfactory.

Above all, the low quality of the casting surface was unsatisfactory. The coating used contains, among other things, ethyl silicate 40, zirconium silicate, ethyl ethoxycellulose, which brings considerable costs.

The above-mentioned shortcomings are eliminated by the coating material, which refines the surface of metal alloy castings according to the invention, characterized in that it contains 50 to 6US6 wt. quartz, 30 to 40 wt. water glass, 0.1 to 0.4 wt. maleic anhydride adduct to levopimaric acid,

0.1 to 0.2 wt. % concentrated ammonia, 5 to 13 wt. % demineralized water and optionally 0.05 to 0.15 wt. % dye, whereby the mutual weight ratio of quartz and water glass is 1.5 to 1.7:1 and the mutual weight ratio of the maleic anhydride adduct to levopimaric acid and concentrated ammonia is 2.2 to 2.4:1.

The coating composition according to the invention is further characterized in that it contains 54.90 wt. % of quartz, 34.10 wt. % of water glass, 0.22 wt. % of maleic anhydride adduct to levopimaric acid, 0.095 wt. % of concentrated ammonia, 10.585 wt. % of demineralized water and 0.10 wt. % of

dyes, especially ostazin red HB, the weight ratio of quartz and water glass being 1.58:1 and the weight ratio of the maleic anhydride adduct to levopimaric acid and concentrated ammonia being 2.32:1.

The coating material according to the invention surpasses the previously used coating material which was kneaded. Tests have proven the long-term stability of the material which solidifies only by evaporation of water and absorption of carbon dioxide from the air.

Furthermore, the high and standard quality of the casting surface was found, which is comparable to the quality of the casting surface when using foreign materials /for example, RK-3 fi Deutaurum, Wipla fi Krupp or material fi Ercodent/.

The coating material according to the invention can be produced only from domestic raw materials, with its advantage being easy fitting of castings from the mold and easy removal of the remaining sealing materials. A great advantage of the coating material according to the invention, in addition to its easy and cheap preparation, is its color and the possibility of adjusting the viscosity by adding water. From a safety point of view, it is not insignificant that the coating material does not contain flammable or toxic solvents.

Table 1 shows some values in comparison with previously used coatings.

Table 1

A B C D E Warehouse- Time Mixing Ease Quality matter properties validity /years/ drying /min/ surface of the wax model casting equipment surface of a casting BK-3 3 10-20 1 1 1 Wipla 3 10-20 1 1 1 Silicon L 0 10-20 1 ^point 3 3 According to example 1 1 and 10-20 1 1 1 According to example 2 1 and 10-20 1 1 2 According to example 3 1 and 10-20 1 1 2

Note: - rating of properties C, D, E: 1 - very good

- satisfactory

- unsatisfactory

- property evaluation A: a - shelf life for one year without change, the substance could not be monitored for longer

- property evaluation C: b - wax model previously degreased with alcohol

The application of the coating material according to the invention is very easy. After shaking, the material is applied with a brush in one continuous layer. The drying time is determined by the thickness of the layer and ranges from 10 to 20 minutes, which is in accordance with the technology of processing castings. After drying, the model is cast in the usual way.

The following examples merely illustrate the coating composition according to the invention, but do not limit it in any way.

Example

220 g of finely ground maleic anhydride adduct to levopimaric acid /Abimal 101/ are placed in a boiling flask and 885 ml of demineralized water. 95 ml of 25% ammonia are added and heated under reflux until the entire amount is dissolved.

After cooling to approximately 30 °C, 1,200 g of a yellow soapy mass is formed, the ammonium salt of the maleic anhydride adduct to levopimaric acid.

In a suitable container (polyethylene, polypropylene, stainless steel, glass), 34.1 kg of water glass is diluted in 9.70 kg of demineralized water while stirring. Then, the prepared solution of the ammonium salt of the maleic anhydride adduct to levopimaric acid is added.

After sufficient mixing, 54.9 kg of quartz and 100 g of ostazin red HB are added and allowed to stir until a homogeneous suspension is formed.

Claims (2)

SUMMARY OF THE INVENTION Coating composition for refining the surface of metal alloy castings, water-dilutable, based on quartz and water glass, characterized in that it contains 50 to 60% by weight. quartz, 30 to 40 wt. 0.1 to 0.4 wt. % of an adduct of aaleinic anhydride to levopiaaric acid, 0.01 to 0.2 wt. concentrated ammonia, 8 to 13% haot. deaineralized water and optionally 0.05 to 0.15% haot. The ratio of quartz to waterglass is 1.5 to 1.7: 1, and the ratio of maleic anhydride to levopiaaric acid adduct to concentrated ammonia is 2.2 to 2.4: 1. 2. The coating of claim 1, comprising 54.90% haot. quartz, 34.10 * haot. water glass, 0.22 * haot. aalein anhydride adduct to levopiaaric acid, 0.095 * haot. concentrated ammonia, 10.585 * haot. demineralized water and 0.10 * haot. dyes, in particular ostasin red HB, wherein the quartz / water glass ratio is 1.58: 1 and the weight ratio of the adduct of aaleinic anhydride to levopiaaric acid and concentrated ammonia is 2.32: 1.