Composition for anti-corrosion protection and method of obtaining it

FIELD: chemistry.

SUBSTANCE: composition includes binding agent - modified with hexamethylentetramine mixture of tal pitch and technical lignosulfonates in presence of catalyst - zinc oxide, tal modified colophony, pigments - aluminium powder and titanium dioxide, zinc phosphate, neutralising filler - calcium oxide and/or calcium hydroxide and/or chalk and/or microcalcite and/or microtalc, hardener- polyethylenpolyamine and organic solvent. Composition is obtained by first mixing (modification) mixtures of tal pitch, technical lignosulfonates and hexamethylentetramine at temperature 120-140°C in presence of catalyst - zinc oxide. Mixture is cooled, tal modified colophony, pigments are added. Neutralising filler, hardener and solvent are added.

EFFECT: increased light-resistance of coating, extension of colour range and quick drying.

3 cl, 1 tbl

The invention relates to the paint industry, in particular the production of anticorrosion coatings based on by-products of the pulp and paper industry (technical lignosulfonates, tall oil pitch). Special use - corrosion protection of reinforced concrete and metal structures production plants chemical plants and external surfaces of equipment, operating in conditions of high humidity, containing in the atmosphere, sulfur dioxide, hydrogen sulfide, chlorine, ammonia.

The closest technical solution of the present composition for corrosion protection is a composition, comprising a binder - modified-hexamethylenetetramine mixture of tall oil pitch and lignosulfonates in the presence of a catalyst is zinc oxide, tall oil modified rosin, pigments, aluminum powder and titanium dioxide, zinc phosphate (see patent RU 2051937, publ. 10.01.1996). The downside of it is high water absorption, low resistance, the coatings of dark color, long term drying. The invention solves the problem: improving the light fastness, the expansion of the color gamut and reduce the drying period of the protective coating.

To achieve this technical result, the composition for corrosion protection includes vacuume - modified by hexamethylenetetramine mixture of tall oil pitch and lignosulfonates in the presence of a catalyst is zinc oxide, tall oil modified rosin, pigments, aluminum powder and titanium dioxide, zinc phosphate, neutralizing the filler is calcium oxide and/or calcium hydroxide, and/or chalk, and/or microsilica, and/or micro-talc, hardener - polyethylenepolyamine and an organic solvent in the following ratio, wt.%:

the above binder containing:

A distinctive feature of the proposed structure from the specified visiitng closest to him, is the fact that the composition further comprises a neutralizing filler is calcium oxide and/or calcium hydroxide, and/or chalk, and/or microsilica, and/or micro-talc, hardener - polyethylenepolyamine and an organic solvent in the following ratio, wt.%:

the above binder containing:

The closest technical solution to p is antigenome method for producing a composition for corrosion protection is the way, including modification and blending of components (see patent RU No. 2051937, publ. 10.01.1996).

The drawbacks are the low quality of the product and low productivity, the duration of mixing of the components.

The invention solves the problem of improving product quality, increasing productivity.

To achieve this, the technical result in the beginning spend modification in the reactor a mixture of tall oil pitch and technical lignosulfonates with hexamethylenetetramine in the presence of a catalyst of zinc oxide at a temperature of 120÷140°C, stirring for 2.5÷3 hours, after which the mixture is cooled to a temperature of 60÷80°and add tall modified rosin, pigments-titanium dioxide and aluminum powder, zinc phosphate, and then determine the acid number of the resulting composition and add neutralizing the filler is calcium oxide and/or calcium hydroxide and/or chalk, and/or microsilica, and/or micro-talc to an acid number of 0÷25 mg KOH/g, and then mechanically mixing the components is not less than 1 hour, after which the composition is cooled to a temperature not higher than 30°and add the hardener - polyethylenepolyamine and an organic solvent to the viscosity of the 60÷70 C.

Distinctive features of the proposed method from the specified visiitng most is Lyskovo to him, is that in the beginning spend modification in the reactor a mixture of tall oil pitch and technical lignosulfonates with hexamethylenetetramine in the presence of a catalyst of zinc oxide at a temperature of 120÷140°C, stirring for 2.5÷3 hours, after which the mixture is cooled to a temperature of 60÷80°and add tall modified rosin, pigments - titanium dioxide and aluminum powder, zinc phosphate, and then determine the acid number of the resulting composition and add neutralizing the filler is calcium oxide and/or calcium hydroxide, and/or chalk, and/or microsilica, and/or micro-talc to an acid number of 0÷25 mg KOH/g, and then mechanically mixing the components is not less than 1 hour, after which the composition is cooled to a temperature not higher than 30°and add the hardener - polyethylenepolyamine and an organic solvent to the viscosity of the 60÷70 C.

The protective coating of known composition (prototype) has a high viscosity due to the content of components having a high acid number: rosin tall (175-180 mg KOH/g) and tall oil pitch (50÷70 mg KOH/g). In a known composition (prototype) high content of free fatty acids causes an undesirable slow down the drying. To eliminate stickiness is proposed to add in floor fillers: microsilica, micro-talc, calcium oxide, hydraotes the calcium, chalk in the number 1÷10 wt.% depending on the acid number of the components used in the coating.

In the tall pitch and tall oil rosin containing resin and fatty acids. Resin and fatty acids react with calcium oxide, neutralized and the product of neutralization is formed calcium soap. Using the acid number is calculated required to neutralize the amount of calcium oxide or other neutralizing fillers.

Included in the wound filler microsilica, and/or micro-talc and/or calcium oxide and/or calcium hydroxide, and/or chalk protect from light exposure, because it can reflect UV, IR and radiation in the visible region of the spectrum.

The protective coating is prepared in the following way: in the beginning carried out in a reactor modification of a mixture of tall oil pitch and technical lignosulphonate with hexamethylenetetramine in the presence of a catalyst of zinc oxide at a temperature of 120÷140°C, stirring for 2.5÷3 hours, the mixture is then cooled to a temperature of 60÷80°and add tall modified rosin, pigments and fillers. Modified rosin can be of two types, namely, rosin modified fumaric acid and rosin, modified glycerol (see THE 13-4000177-01-83).

Prior pereir fill the her to fraction with particles of not more than 12 μm ensures uniformity of coating, no visible inclusions. This is followed by mechanical mixing of the components for at least 1 hour. After the composition is cooled to a temperature not higher than 30°and add a polyethylenepolyamine, organic solvent to the viscosity of 60-70 C. as the organic solvent can be used: ortho-xylene oil THAT 38.101254-72, toluene GOST 9880-76, BitSpirit GOST 3134-78, acetone GOST 2768-84.

The viscosity of the coating is determined on the viscometer of type B3-246 with the nozzle diameter of 6 mm according to GOST 9070-75 at a temperature of (20±0,5)°C. the Coating is applied on the sample sheet size (150×70)mm. Determine the drying time of the coating to a tack-free surface and 3rd degree, determine the adhesion of the coating to the metal (GOST 15140-78) and acid number of the coating according to GOST 5476-80. Introduction polyethylenepolyamine 5,0÷10,0% knits spatial structure of film-forming substances (tall peck, lignosulfonates), which leads to the film strength corrosion-resistant coating.

Acid number is determined according to GOST 5476-80. The hinge 2±0.0002 g of the coating is dissolved in a conical flask with a capacity of 250 ml in 30 ml alcohol-toluene mixture (1:1) and titrate with the resulting solution in the presence of phenolphthalein 0.1 N. alcoholic KOH solution until the pink color. Acid number is calculated by the formula:

X=VT1000/m where:

V - volume of 0.1 N. alcoholic solution of KOH, itrash is recommended for titration, ml;

T is the titer of 0.1 N. alcoholic solution of KOH, g;

m is the mass of a sample coating,

Adding neutralizing fillers from 1÷10 wt.% acid number of the coating varies in the range 0÷25 mg KOH/g Formed calcium soap accelerates the drying process of the coating and reduces stickiness. Example: protective coating was prepared in the following way: in the beginning was performed in the reactor modification of a mixture of tall oil pitch and technical lignosulphonate with hexamethylenetetramine in the presence of a catalyst of zinc oxide at a temperature of 120÷140°C, stirred for 2.5 hours, then cooled the mixture to a temperature of 80°and added rosin tall oil, pigments and fillers, were mechanical mixing of components within 1 hour. Upon cooling of the composition to 30°With added polyethylenepolyamine and an organic solvent to a viscosity of 60 C. the viscosity of the coating was determined by viscometer type B3-246 with the nozzle diameter of 6 mm according to GOST 9070-75 at a temperature of (20±0,5)°C. the Coating was applied on the sample sheet size (150×70) mm Determined the drying time of the coating to a tack-free surface and level 3, defined the acid number of the coating according to GOST 5476-80. The data of comparative tests of antirust coating is shown in the table.

Improving the light fastness, the expansion of the color gamut and the protective coating is achieved by stosowanie composition includes titanium oxide and neutralizing the filler microsilica, and/or micro-talc and/or calcium oxide and/or calcium hydroxide, and/or chalk.

1. Composition for corrosion protection, comprising a binder - modified-hexamethylenetetramine mixture of tall oil pitch and lignosulfonates in the presence of a catalyst is zinc oxide, tall oil modified rosin, pigments, aluminum powder and titanium dioxide, zinc phosphate, neutralize the second filler - the calcium oxide and/or calcium hydroxide, and/or chalk, and/or microsilica, and/or micro-talc, hardener - polyethylenepolyamine and an organic solvent in the following ratio, wt.%:

2. Composition for corrosion protection according to claim 1, characterized in that it contains a neutralizing filler microsilica, and/or micro-talc and/or calcium oxide and/or chalk with particles of not more than 12 μm.

3. A method of obtaining a composition for corrosion protection, namely, that first by m is the modification in the reactor a mixture of tall oil pitch and technical lignosulfonates with hexamethylenetetramine in the presence of a catalyst of zinc oxide at a temperature of 120-140° With stirring for 2.5-3 h, after which the mixture is cooled to a temperature of 60-80°and add tall modified rosin, pigments - titanium dioxide and aluminum powder, zinc phosphate, and then determine the acid number of the resulting composition and add neutralizing the filler is calcium oxide and/or calcium hydroxide, and/or chalk, and/or microsilica, and/or micro-talc to the values of the acid number 0-25 mg KOH/g, and then mechanically mixing the components for at least 1 h, after which the composition is cooled to a temperature not above 30°and add the hardener - polyethylenepolyamine and an organic solvent to the viscosity of 60-70 C.