RU2468053C1 - Heat-resistant anticorrosion composition - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to paint and varnish anticorrosion materials and may be used to protect metal surfaces operated under high temperature conditions under action of high corrosion medium: oil products, fresh and sea water, and also domestically and industrially. A heat-resistant anticorrosion composition for a coating contains an epoxide diane resin ED-20, modified with a heat resistant organoboron polymer - polymethylene-n-triphenyl ether of boric acid, a plasticiser - dioctylphthalate, a micro-reinforcing filler - wollastonite, a technical pigment - carbon, a reinforcing filter - microsilica, an organic dissolvent and a hardener.

EFFECT: improved physical-mechanical and thermal parameters of a coating and higher sedimentation stability of a composition in process of storage.

2 tbl, 4 ex

Description

The invention relates to paint and varnish anti-corrosion materials and can be used to protect metal surfaces operated at elevated temperatures when exposed to high corrosive environments: oil products, fresh and sea water, as well as in everyday life (painting of furnace systems) and industry (for protecting engines and exhaust automobile systems, chimneys and furnaces, thermal insulation of structures).

A known composition for heat-resistant coatings [1], including polyphenylsiloxane resin, acrylate copolymer, aluminum powder and organic solvent, filler and rheological additive. At the same time, microtalc is used as a filler, and aerosil and bentonite as a rheological additive. The disadvantage of this composition is that it has a reduced sedimentation stability during storage, and coatings made on its basis have insufficiently high efficiency under operating conditions.

A known composition for a protective coating [2] containing a polyphenylsiloxane resin, a copolymer of butyl methacrylate and methacrylic acid, a pigment and an organic solvent. The disadvantage of this composition is that it does not have high enough film hardness and low sedimentation stability during storage.

As a prototype, a composition [3] was selected containing a polyphenylsiloxane polymer, an acrylic copolymer, a heat-resistant pigment, a filler — potassium aluminosilicate, wollastonite, a rheological additive, and an organic solvent.

The disadvantage of the composition is that the compositions based on polyphenylsiloxane polymer have a sufficiently long drying time. The second disadvantage is that during the operation of products with a large thickness (30-40 microns), the heat-resistant pigment, which is part of the composition, can act as a stress concentrator due to local temperature differences, which leads to a decrease in the protective properties of the coating and, ultimately to its destruction.

The proposed technical solution is aimed at increasing the effectiveness of the protective coating by increasing the physical and mechanical properties of the coating and will solve the problem of reducing the protective properties of the coating during prolonged exposure to high temperatures.

The technical result of the invention is:

- improvement of physical, mechanical and thermal characteristics of the coating. This result is achieved by using a heat-resistant polymer - polymethylene-n-triphenyl ester of boric acid. It is known [4] that thermal degradation of this polymer occurs without any thermal effects. The absence of thermal effects during decomposition is an important advantage of the organoboron polymer, since during the high-temperature operation of products based on it there will be no temperature gradient in the mass of material, which eliminates the appearance of stress concentrators in the product, due to local temperature differences. In addition, this polymer has a high resistance to thermal effects due to the presence of methylene groups, which create an additional framework;

- increased sedimentation stability of the composition during storage. This result is achieved when using silica fume as a reinforcing filler, acting as a rheological additive. Particles of silica fume have a size of from 0.1 to 0.4 μm, which is smaller than the average particle size of the filler (wollastonite) and pigment (carbon black), so it is distributed fairly uniformly in the polymer matrix, playing the role of not only a rheological additive, but also a reinforcing component ;

- reducing the cost of the composition due to the exclusion of expensive heat-resistant pigments and rheological additives from the composition. Partially, the role of a heat-resistant filler is played by wollastonite having a melting point of 1540 degrees Celsius and a low temperature coefficient of linear expansion. Wollastonite is perfectly dispersible in polar and non-polar solvents and, due to its morphology, contributes to a better distribution of the remaining components of the filled system. In addition, the introduction of wollastonite gives wear resistance and hardening of materials. Wollastonite is a synergist in its interaction with anti-corrosive pigments and a non-carcinogenic alternative to asbestos [5]. The use of wollastonite in a certain combination with carbon black and silica fume leads to increased strength, wear resistance, and also improves thermal insulation, refractory and technological properties. The cost of wollastonite is 10 times less than the cost of heat-resistant filler.

The proposed heat-resistant anti-corrosion composition for coating has the following ratio of components, wt.%

Epoxy Dianova resin ED-20 - 35.5-42.5

Plasticizer dioctyl phthalate - 3.5-4.5

Polymethylene-n-triphenyl ester of boric acid - 3-8

Micro-reinforcing filler wollastonite - 6-10

Carbon black pigment - 7-10

Reinforcing filler silica fume - 6-10

Organic solvent - rest up to 100

Hardener Polyam BS-10 based on aromatic amines - 13.4-16.1 (over 100%)

The materials used in the composition of the proposed composition are readily available: they are produced on an industrial scale and are regulated by regulatory documents. The solvent used is acetone (GOST 2768-84), toluene (GOST 14710-78). As a heat-resistant polymer, an 80% solution of polymethylene-p-triphenyl ester of boric acid in acetone is used.

The composition is prepared as follows. The calculated amount of an organic solvent (20% of the amount of solvents) and an organoboron polymer are charged into the first reactor. Stirred at a temperature not exceeding 40 degrees Celsius until the polymer is completely dissolved. The calculated amount of solvent, epoxy resin, and plasticizer dioctyl phthalate is loaded into the second reactor. The mixture is stirred for 2 hours, then fillers, pigment are charged and dispersed for 3 hours. Then the mass from the first reactor is pumped into the second and stirred for 1 hour. Then a sample of the composition is taken to determine quality indicators. The finished composition is pumped to packaging.

The proposed heat-resistant composition for coating can be applied to the protected surface with a brush or roller.

To determine the quality indicators of the obtained heat-resistant anticorrosive composition, the composition was applied to metal plates with a brush and dried at room temperature.

The deformation-strength properties of the coating were tested on an OR adhesive meter. Measurement of the strength properties of the coating in this way gives more complete information about the amount of adhesion of the coating to the metal and expands the scope of this composition.

The present invention is represented by examples 1-4. Table 1 shows examples of the proposed compositions of heat-resistant compositions for coatings. Table 2 shows the test results of the properties of coatings from the compositions shown in table 1.

Table 1 The composition of heat-resistant anti-corrosion composition Name of ingredients The content of ingredients, wt.% Composition number one 2 3 four Epoxy Dianovy resin ED-20 35.5 37.5 39.5 42.5 Plasticizer dioctyl phthalate 3,5 3.8 4.0 4,5 Polymethylene-n-triphenyl ester of boric acid 3 four 6 8 The microreinforcing filler wollastonite 6 10 8 6 Carbon black pigment 7 8 10 9 Reinforcing filler silica fume 6 8 6 10 Acetone 10 10 10 10 Solvent 646 29th 18.7 16.5 10 Hardener Polyam BS-10 based on aromatic amines ^* 13,4 14.2 14.9 16.1 * Hardener concentration,% (mass.), Calculated with respect to epoxy

table 2 Coating Properties Test Results The name of indicators By examples Prototype one 2 3 four Drying time to degree 3, h - 0.3 0.3 0.3 0.3 Heat resistance of the coating, ° С 600 600 600 650 670 Adhesion to a metal surface, point one one one one one Adhesion to a metal surface, determined by normal tearing, N / cm - 23.9 23.14 23.8 24.0 Coating strength upon impact, cm - thirty 35 32 38 The hardness of the film, srvc. units 0.5-0.54 0.5 0.5 0.52 0.53 Resistance to salt fog, h one hundred one hundred one hundred one hundred one hundred Film resistance to static action at 20 ± 20С, h water 120 720 720 720 720 gasoline 72 200 200 200 200 Mineral oil 72 200 200 200 200

Thus, the claimed composition for coating has a high sedimentation stability during storage, is characterized by rapid drying, provides heat-resistant anticorrosive coatings with high adhesion to the substrate and resistance to various aggressive environments. To test the effectiveness of the proposed composition, laboratory tests of the heat-resistant anticorrosive composition were carried out, which showed an improvement in the physical, mechanical and thermal parameters of the coating

Information sources

1. Patent RU 2137793, ⁶ C09D 183/06, C09D 5/08, C09D 133/06, 1999.09.20.

2. Patent RU 2157397, ⁷ C09D 183/04, C09D 5/08, 2000.10.10.

3. Patent RU 2266937, ⁷ C09D 183/04, C09D 5/08, 2004.04.12.

4. Korneva O.V., Lensky M.A., Belousov A.M., Androshchuk A.A., Ananyeva E.S. Features of the thermal decomposition of polyesters and polymethylethers of phenols and boric acid. - Prospects for the creation and use of condensed high-energy materials: Reports of the II scientific and technical conference of young scientists September 25-26, 2008 (Biysk, Altai Territory). - Biysk: Publishing House of BTI AltGTU, 2008 .-- 222 p. - S.93-98.

5. Nazarenko, V.V. Anisotropic silicate fillers: special properties in coatings and coatings // Paintwork materials and their use, No. 1-2, 2008. - p.25-33.

Claims (1)

Heat-resistant anticorrosive coating composition containing ED-20 epoxy-diane resin, dioctyl phthalate plasticizer, carbon black pigment, micro-reinforcing filler wollastonite, organic solvent, hardener, characterized in that the ED-20 epoxy-diane resin is modified with heat-resistant organoboron polymer n-polymer -triphenyl ether of boric acid, and as a reinforcing filler contains silica fume, in the following ratio, wt.%:
Epoxy Dianovy resin ED-20 35.5-42.5 Plasticizer dioctyl phthalate 3.5-4.5 Polymethylene-n-triphenyl ester of boric acid 3-8 The microreinforcing filler wollastonite 6-10 Carbon black pigment 7-10 Reinforcing filler silica fume 6-10 Organic solvent The rest is up to 100 Hardener 13.4-16.1 (in excess of 100%)