RU2599513C1 - Indicator paint for detection of hydrogen fluoride and its aqueous solutions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to rapid indication means intended for visual detection of leaks and spills of hydrogen fluoride and its aqueous solutions. Indicator paint consists of (wt%): quinalizarin complex with europium (III) - 2.5÷3.5; copolymer of vinyl chloride with vinyliden chloride of VHVD-40 type - 3.0÷4.0; barium sulphate - 20.0÷30.0; titanium dioxide - 20.0÷30.0; butyl acetate - 2.0÷14.0; xylene - 18.5÷52.5.

EFFECT: higher selectivity, reliability and accuracy of indication during visual detection of leaks and spills of hydrogen fluoride and its aqueous solutions.

1 cl, 1 dwg, 3 tbl, 3 ex

Description

The claimed invention relates to an express means of indication, specifically, an indicator paint intended for the visual detection of leaks and spills of hydrogen fluoride (HF) and its aqueous solutions (hydrofluoric acid) when they come in contact with controlled surfaces painted with indicator paint.

Hydrogen fluoride and hydrofluoric acid, widely used in chemical, metallurgical, glass and other industries, belong to hazard class I [1].

For visual detection of HF, indicator tubes [2] and acid-base indicator papers [3] are used.

The disadvantage of indicator tubes, intended mainly for air control, is the limited suitability of these tools for detecting local places of leakage and spills and, therefore, unnecessary time and labor costs during the analysis.

The main disadvantages of acid-base indicator papers are:

- non-selectivity to all compounds with an acidic character;

- the need to use additional means for fixing on a controlled surface;

- the disappearance of the indicator effect during the neutralization of the substances causing it.

The closest to the claimed invention in terms of functionality and technical essence is indicator paint (IR) for determining leaks of substances having a pH <3, including hydrogen fluoride, manufactured by RAMCO® Manufacturing Company, Inc. (Acid detecting paint, ON GUARD ™) [4].

This indicator paint is accepted by us as a prototype.

IR is a mixture of an acid-base indicator and excipients in a binder solution. Upon contact of HF and / or hydrofluoric acid on the coatings obtained by applying the indicator paint, the coating yellow changes to bright red.

The disadvantages of the prototype include: non-selectivity to all compounds with an acidic nature, as well as the disappearance of the indicator effect when neutralizing the substances causing it.

The aim of the invention is indicator paint applied to a controlled surface, designed for visual express detection of leaks and spills of hydrogen fluoride and its aqueous solutions, characterized by high selectivity, long life and exhibiting a stable contrast indicator effect in a wide temperature range.

This goal is achieved by the fact that the inventive indicator paint is a suspension of pigments, fillers (barium sulfate, titanium dioxide) and a complex of quinalizarin with europium (III) in a binder solution (copolymer of vinyl chloride with vinylidene chloride grade VHVD-40), in the following ratio of components, wt . % (Table 1):

For a better understanding of the essence of the claimed invention, the following are examples of the manufacture, use and principle of operation of the RJ.

Example 1. Obtaining a complex of quinalizarin with europium (III)

1.67 L of quinalizarin solution (0.03 mol / L) and 0.17 L of a solution of europium (III) salt, for example europium acetate, (0.30 mol / L) in dimethyl sulfoxide are mixed. To the resulting solution was added 9.0 L of distilled water. The precipitate formed is filtered off, washed with three portions of distilled water, 100 ml each, and dried at t = 50 ÷ 60 ° C to constant weight. Yield: 19.8 g.

The complex of quinalizarin with europium (III) is a solid powdery substance of black-violet color.

Example 2. Obtaining indicator paint

The components in the appropriate formulation ratio (see table 2) are loaded into a bead mill and dispersed to a particle size of 40-45 microns. The resulting indicator paint is stored in hermetically sealed containers.

Example 3. The use of indicator paint

Indicator paint is applied under normal climatic conditions to a controlled surface with a brush, roller, or pneumatic spray. It is allowed to apply indicator paint both on unpainted metal surfaces (carbon and alloy steel, copper, aluminum, nickel and their alloys) of products, as well as on anticorrosive coatings based on oil and epoxy enamels.

After drying, the paint forms an indicator coating, which is used to visually detect leaks and spills of hydrogen fluoride and its aqueous solutions.

The indicator coating retains its properties for at least 1 year.

A contrast indicator effect is visually recorded when hydrogen fluoride or its aqueous solutions (concentration of 0.1% or higher) are in contact with the indicator coating. The gray-violet color of the indicator coating changes to orange. The time of manifestation of the indicator effect is from several seconds at positive temperatures to 1 ÷ 5 min at temperatures below -10 ° C.

Indication effect persists for at least 3 months.

The selectivity of the indicator paint is confirmed by the data given in table 3.

Literature

1. GOST 10484-78

2. Indicator tube for hydrogen fluoride TI- [HF-0,1]

http://www.christmas-plus.ru/itgaz/itairanalysis/ftoristyivodorod.

Dräger hydrogen fluoride indicator tubes. Catalog No. 8103251, CH 30301. Dräger-Tubes & CMS Handbook.

Soil, Water, and Air Investigation as well as Technical Gas Analysis, 16 ^th edition, Lübeck, 2011.

3. Patent SU 1127935, G01N 31/22, 1984. A method of obtaining an acid-base indicator paper for determining the pH of a solution. Authors: Falin V.A., Goncharov A.E., Fomin N.A., Zhukova T.A., Ostrovskaya V.M.

4.http: //www.ramco-safetyshields.corn/html/products_1.htm

Claims (1)

Indicator paint intended for the visual detection of leaks and spills of hydrogen fluoride and its aqueous solutions, characterized in that the composition of the indicator paint includes, by weight. %: complex of quinalizarin with europium (III) - 2.5 ÷ 3.5; a copolymer of vinyl chloride with vinylidene chloride brand VHVD-40 - 3.0 ÷ 4.0; barium sulfate - 20.0 ÷ 30.0; titanium dioxide - 20.0 ÷ 30.0; butyl acetate - 2.0 ÷ 14.0; xylene - 18.5 ÷ 52.5.

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