RU2081153C1 - Composition for treatment of solid surfaces - Google Patents

Abstract

FIELD: chemical industry. SUBSTANCE: composition comprises, %: mixture of perfluoropolyetheracids of formula 1 and 2, where n is 8-50, 0.01-7.00; saturated cyclic perfluorohydrocarbon, up to 100. Structure of compounds of formula 1 and 2: C₃F₇O(C₃F₆O)_nCOOH, C₃F₇O(C₃F₆O)_nCF₂COCF₃.. EFFECT: improved properties. 2 cl, 2 tbl

Description

 The invention relates to the field of organic chemistry, and in particular to compositions used for processing hard surfaces to reduce their surface energy, which allows you to adjust surface properties such as wear resistance, adhesion, hydrophobicity.

 The proposed composition can be used for processing hard surfaces, both metallic and non-metallic: in friction pairs of various components and mechanisms in order to reduce the coefficient of friction and wear, metalworking tools and tooling in order to increase their wear resistance, rubber products, to reduce the coefficient of friction and wear.

 A known composition, which when applied to a solid surface forms a lubricating coating / 1 /. It contains fluorinated alcohols telomeres and 70-80% wt. fluorinated adipic acid diesters.

 However, the resulting coating is unstable. It has weak adsorption to the surface and low thermal stability.

Closer to the proposed is the composition / 2 /. This composition is a lubricating oil containing 0.05-1% wt. perfluorinated fatty acids of the general formula CF ₃ (CF ₂ ) _n COOH at n = 5-20 and, as a basis, synthetic esters, polysiloxane, hydrocarbon or fluorocarbon fluids. The acid, which is part of the lubricating oil, prevents its spreading due to the effect on surface energy.

 However, the short chain length of the acid molecule does not provide its thermal stability. In addition, the scope of this composition is limited by the possibility of its use only as a lubricating oil, which remains on the surface in the liquid phase.

 The present invention is directed to the solution of creating an ozone-safe composition for treating a hard surface in order to give it new qualities: wear resistance, hydrophobicity, adhesion due to the formation of a monomolecular stable low-energy coating on it.

 The technical result obtained by carrying out the invention will consist in organizing the industrial production of an ozone-safe composition, providing an increase in the resource of work, increasing productivity and operational characteristics of machines and mechanisms, processing tools and technological equipment.

The essence of the invention lies in the fact that as the basis of the composition for treating a solid surface, a cyclic limit perfluorocarbon is used, for example, perfluorodimethylcyclohexane, perfluorodecalin, perfluoroethylcyclohexane, into which an additive of a mixture of perfluoropolyether acids and β-ketones of the formula is introduced:
C ₃ F ₇ O (C ₃ F ₆ O) _n COOH
C ₃ F ₇ O (C ₃ F ₆ O) _n CF ₂ COCF ₃
n 8 50
The specified additive exists as a single substance obtained by photooxidation of hexafluoropropylene. In this case, polyesters are formed not only with fluorohydride end groups, but also with fluoroformate. Upon further processing of these polyesters (thermal stabilization and saponification), an inseparable mixture of perfluoropolyether acids and β-ketones is formed. (V. A. Ponomarenko, S. P. Krukovsky, A. Yu. Lybina. "Fluorine-containing heterochain polymers." Publishing House "Science", Moscow, 1973, 118-124).

 As it was established experimentally, a mixture of perfluoropolyether acids and β-ketones unlimitedly dissolves in cyclic saturated perfluorocarbons and at the same time does not dissolve in traditional organic solvents (e.g. alcohols, acetone, gasoline, etc.) When applying the proposed composition to a solid the surface after drying, a stable monomolecular film is formed, visible with an electron microscope. Its thickness is 40-80 angstroms. According to the authors, the monomolecular film, as it were, wipes microcracks and evens out microroughnesses, which leads to a decrease in the friction coefficient of this surface and increases wear resistance, gives anti-adhesive properties and increases its hydrophobicity.

 It was also found that the ratio of ingredients in the composition depends on the material of the processed surface.

 With more loose structures: plastic, rubber, ceramics, the amount of a mixture of perfluoropolyether acids and β-ketones should be from 2% to 7% of the mass. and when processing metals, glass, etc. from 0.01% to 2% of the mass.

Information confirming the possibility of carrying out the invention is given in examples of specific performance shown in tables N 1 and N 2. Metalworking tools and rubber gaskets were treated with solutions of different concentrations of perfluoropolyether acids and β-ketones of the formula:
C ₃ F ₇ O (C ₃ F ₆ O) _n COOH
C ₃ F ₇ O (C ₃ F ₆ O) _n CF ₂ COOF ₃
n 8 50
in perfluorodimethylcyclohexane C ₈ F ₁₆ and perfluorodecaline by dipping them in solution, followed by drying.

 Table 2 presents data confirming the merger of the composition on hydrophobicity.

 The filter paper was treated with the proposed composition with different contents of perfluoropolyether acids and β-ketones in perfluorodimethylcyclohexane, followed by drying, and then its wetting time in water was recorded.

Claims (1)

1. A composition for treating hard surfaces based on fluorinated hydrocarbon containing an additive comprising fluorinated carboxylic acid, characterized in that it contains a cyclic saturated perfluorocarbon as a fluorinated hydrocarbon and, as an additive, a mixture of perfluoropolyether acids and perfluoropolyether ketones of the general formula respectively C ₃ F ₇ O ( C ₃ F ₆ O) _n COOH and C ₃ F ₇ O (C ₃ F ₆ O) _n CF ₂ COCF ₃ , where n 8 50, in the following ratio, wt. Indicated additive 0.01 7.00
Cyclic limit perfluorocarbon Up to 100
2. The composition according to claim 1, characterized in that as a cyclic perfluorocarbon it contains perfluorodimethylcyclohexane.

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