RU2435663C1 - Release agent for metal moulds when making concrete and reinforced concrete articles - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to release agents when producing concrete and reinforced concrete articles. The release agent for metal moulds when making concrete and reinforced concrete articles contains the following, wt %: vegetable oil 2.5-15, vegetable oil ether selected from methyl, ethyl, n-, iso-propyl, n-, iso-, tert-butyl ether 0.5-97.5, mineral oil - the rest.

EFFECT: resistance to low and high temperatures, cost effectiveness, preventing formation of spots on the surface of concrete articles and sticking of concrete to the metal mould, preventing corrosion of metal moulds, easy preparation and improved environmental properties.

2 cl, 2 tbl

Description

The invention relates to the technology of manufacturing products from concrete and reinforced concrete, namely, lubricants for molds in the production of concrete and reinforced concrete products.

Known lubricant for forms, consisting of two parts of petroleum jelly and one part of stearin. This grease facilitates the formwork and improves the appearance of the product, economical (consumption 3 g / m ² ). Since the lubricant has a high viscosity, applying it to the mold and subsequent cleaning of the mold are laborious operations. In addition, to achieve the effect, the lubricated form must be filled with concrete immediately, which is not technologically advanced (A.S. 153522, C10M 7/12, publ. 1962).

Known lubricant consisting of mineral oil with the addition of 0.01-3% hydroxycarboxylic acid (tartaric or citric). The lubricant is easy to apply, facilitates the formwork, but does not guarantee the absence of pore formation and causes corrosion of the metal form (A.C. 4778731, B28B 7/36, publ. 1975).

Known emulsion lubricant consisting of paraffin, stearin, triethanolamine, acidic emulsol and 87-90% water. Lubrication facilitates formwork and reduces pore size on the surface of the product. The lubricant is difficult to prepare, inhomogeneous, causes corrosion of a metal form, is not applicable in the manufacture of products of complex configuration (A.S. 79086, B28B 7/36, publ. 1980).

The known composition of a two-component aqueous emulsion for lubricating the formwork, facilitating the removal of hardened concrete products. At least one fatty acid and (or) saponified vegetable oil (rapeseed, sunflower, beetroot, etc.) is used as its first component (1-10% by weight of the emulsion), and as a second component (10-20%) of the mass of the first component is biodegradable emulsifiers and (or) surfactants, mainly of plant origin, acceptable for use in the food industry, for example ricin peroxylate. Lubrication facilitates the formwork, reduces the pore size on the surface of concrete products, but is not effective enough in the manufacture of products of complex shape, with increased demands on the quality of the surface of concrete and, in addition, causes corrosion of metal forms. The lubricant is uneconomical, its components are hazardous substances (Pat. Germany No. 4422470, C10M 173/02 and others, publ. 1994).

Known lubricant containing 4-14% of VAT residues of synthetic fatty acids, 0.3-2% of synthetic emulsifiers OP-7 or OP-10 and water. The lubricant ensures the surface quality of a product of category A1 (GOST 13015.0-83), however, it is unstable and causes corrosion of metal forms. Its preparation is laborious and requires high temperatures (A.S. 2021112, B28B 7/36, publ. 1994).

Known lubricant designed specifically for the manufacture of reinforced concrete products of complex configuration. It contains 50-85% of spent mineral oil and 15-50% of the bottom residue of soap production from vegetable oils (TU 18-RSFSR 486-77. Fat composition). Lubrication allows you to get the surface of a product of class A1-A2 (GOST 13015.0-83), but it leaves spots on the surface of concrete and molds, causes corrosion of metal forms and is uneconomical (lubricant consumption of 20-30 g / m ² ). In addition, high temperatures are needed to obtain lubricant. Its disadvantages include the fact that the alkaline distillation residue of soap production has a harmful effect on the skin (RU, Pat.2184033, B28B 7/36, publ. 2000).

Closest to the proposed invention (prototype) is a lubricant containing in wt.%: Fatty acid 29.5-5.5, triethanolamine 0.5-1.0, vegetable oil up to 100. The lubricant further contains oligo sodium salt (n- dihydroxy-n-phenylene) thiosulfonic acid (mitophene) 0.01-0.001 wt.%. The grease is resistant to delamination, to the action of low and high temperatures, does not cause corrosion of metal forms, eliminates the formation of spots on the surface of concrete products and the adhesion of concrete to a metal form, easy to prepare. The disadvantages of lubrication include an increased hazard class of components (fatty acids and triethanolamine - moderately hazardous substances), as well as reduced profitability (increased cost of components). (RU, Pat. 2277472, B28B 7/38, publ. 2005).

The problem to which the present invention is directed, is the creation of a new effective release agent for metal molds in the production of concrete and reinforced concrete products in order to expand the range of known lubricants.

The technical result achieved in solving this problem is to create a grease that is resistant to low and high temperatures, economical, eliminating the formation of spots on the surface of concrete products and the adhesion of concrete to a metal form that does not cause corrosion of metal forms, easy to prepare, and having improved environmental properties.

It provides the surface of manufactured products of class A1 and does not have a harmful effect on the human body.

The problem is solved by the proposed release agent for metal molds in the manufacture of concrete and reinforced concrete products containing in wt.%: Vegetable oil (technical or refined, rapeseed or soybean) 2.5-15, vegetable oil ether (methyl, ethyl, n-, iso-propyl, n-, iso-, tert-butyl ether of technical or purified rapeseed or soybean oil) 0.5-97.5, mineral oil - the rest.

Grease is prepared by mixing the components at room temperature. Ready grease is a homogeneous, easily moving, storage-stable liquid from light yellow to light brown.

The grease is applied to the hot or cold surface of the mold cleaned from dust, manually or by a spray gun, after which the molds are filled with concrete.

Examples of specific performance, properties, quality indicators of reinforced concrete products of the proposed new release lubricant (for various compositions in the above dosage ranges of components) and the lubricant of the prototype are shown in tables 1,2. An examination of the test results presented in these tables confirms that the proposed compositions are not inferior in terms of properties and quality indicators of the surface of concrete products and metal molds and confirms its industrial applicability. This is also evidenced by the fact of positive test results at enterprises of the city of Ufa that produce concrete and reinforced concrete products: LLC ZhBZ-2, LLC SU-10.

The inventive lubricant is significantly more economical than the prototype lubricant: the consumption per unit surface of the mold is similar to the prototype at a lower cost of components.

The resistance of the lubricant to the action of low and high temperatures is characterized by a low pour point of the test samples (<-25 ° C), high flash point (> 200 ° C).

Unlike the prototype, the proposed lubricant is low-hazard, since it does not contain substances classified as moderately hazardous in terms of hazard class.

The use of the proposed lubricant ensures that there are no spots on the surface of concrete or reinforced concrete products, which makes it suitable for the manufacture of these products with increased decorative requirements, for example, facade surfaces of buildings and structures, in the construction of stations and distillation tunnels of subways. In addition, the use of the proposed lubricant ensures the absence of traces of cement on the mold, which improves the manufacturability of the manufacturing process of concrete or reinforced concrete products and contributes to the cleanliness of the surface of these products.

Table 1 - Lubricant Compositions Grease components The content of components (wt.%) In the proposed lubricants 1-4 and in the lubricant prototype one 2 3 four Prototype Rapeseed oil, technical 2.5 - - - 94.0 Rapeseed oil, refined - 15.0 - - - Soybean oil, technical - - - 2.5 - Refined Soybean Oil - - 10.0 - - Industrial oil I-20A - 83.0 - - - AU spindle oil 97.0 - 30,0 - - Refined rapeseed oil methyl ester - - 50,0 97.5 - Technical Soybean Oil Ethyl 0.5 - - - - Technical rapeseed iso-propyl ether - - 10.0 - - Technical rapeseed oil n-butyl ether - 1,0 - - - Purified soybean oil tert-butyl ether - 1,0 - - - Stearic acid - - - - 5.5 Triethanolamine - - - - 0.5

Table 2 - Characterization of lubricant, concrete surface and metal molds Lubricant composition one 2 3 four Prototype Homogeneity Yes Yes Yes Yes Yes Formwork conditions Easily, Easily, Easily, Easily, Easily, without damage without damage without damage without damage without damage Surface category according to GOST 13015.0-83 A1 A1 A1 A1 A1 Corrosion
metal mold (20 cycles) No No No No No The ability to reuse the mold without applying grease Yes Yes Yes Yes Yes Grease hazard class according to GOST 12.1.007-76 four four four four 3

Claims (2)

1. Release agent for metal molds in the manufacture of concrete and reinforced concrete products, containing vegetable oil, characterized in that it further comprises a vegetable oil ester selected from the group: methyl, ethyl, n-, iso-propyl, n-, iso-, tert-butyl mineral oil in the following proportions of components, wt.%:
Vegetable oil 2,5-15 Vegetable oil ester 0.5-97.5 Mineral oil Rest 2. Release agent according to claim 1, characterized in that technical or refined rapeseed or soybean oil is used as vegetable oil.