The invention relates to odnoupakovochnye polyurethane film-forming, curing air moisture, which can be used as a varnish or binder in the polymer compositions having anti-corrosion properties. Described film-forming, including 35,0-60,0 wt.% polyoxypropyleneamine with molecular weight of 3000-5000, 14,9-to 27.0 wt.% MDI based on 4,4'-diphenylmethanediisocyanate, 0.1 to 3.0 wt.% N,N-tetrapropylammonium and ethyl acetate and/or butyl acetate, ethyl acetate and/or toluene as an organic solvent in an amount up to 100 wt.%. The resulting film-forming material has anti-corrosion and waterproofing properties, and the ultimate tensile strength is at the level of 24 MPa, elongation at break is at the level of 102%, and the modulus of elasticity is 485 MPa, which allows the use of the present invention in the construction of objects of oil and gas industry, port facilities and power plants. table 4.
The present invention relates to formulations of odnoupakovochnye polyurethane film-forming, curing air moisture is jednoznacnih to obtain anti-corrosion and waterproofing coatings on structures, structures and equipment made of metal, concrete, reinforced concrete, operating in conditions of severe exposure, atmospheric, aggressive aqueous and organic environments, including marine, freshwater and wastewater, crude oil and petroleum products, in pairs of organic and mineral acids and alkalis.
Declare and protective film-forming polymeric composition with its contents can be applied in industrial and civil construction in the oil and gas industry, port facilities and power plants, and other industries.
Known tropicanoe polyurethane binder, cured under the influence of moisture and represents a urethane prepolymer with terminal NCO-groups with a concentration of 6-15%, obtained by reacting a mixture of simple polyetherdiol based on polypropylene glycol with a molecular weight of 3000 carbon units (.E.) - 60-90% and simple polyetherdiol on the basis of glycerol with molecular weight of 3000-6000.E. (10-40%) with a mixture of isomers of diphenylmethanediisocyanate (German patent No. 4236562, IPC5C 08 G 18/10 C 08 L 75/08). Known binder has a high viscosity and is intended solely for polucheniya by introducing water in the composition.
Known polyurethane composition obtained by reacting MDI with a mixture of 50-95 wt.% polyether with a molecular weight of 400-600.E. and a hydroxyl number of 50 to 90 mgKOH/g as one of the polyesters a condensation product of ethyldiamine with propylene oxide. This binder is intended only for strengthening geological formations, loose rock and earth masses and is unsuitable for application of protective coating (patent USSR No. 635859, IPC7C 08 G, 18/32).
Closest to the technical nature of the claimed is tropicabana composition of the brand "Latex (TU 2226-001-13013487-95), intended to receive protective coatings and derived from simple polyetherpolyols and MDI environment ethyl acetate, where as polyetherpolyols it contains polyoxypropylene with a molecular mass (MM) 3000-5000.E., and as MDI is a mixture of isomers of 4,4’-diphenylmethanediisocyanate, in the following ratio of components:
Known composition for coating (Patent RF №2073053, IPC C 09 D 175/08), tech upon receipt and in the process of applying to the protected surface. Formed on the basis of polymer coatings have on ocrite (25-40 μm) only provide mechanical protection of the surface structures, products, equipment and structures from the effects of aggressive environments. In the operation of the coatings, especially in aqueous solutions of acids (pH>7), there is diffusion of water and dissolved acidic impurities through the polymer film to protect surfaces, which leads to a significant reduction in coating adhesion, blistering and the emergence of foci of sub pellicle and pitting corrosion. In addition, the speed of curing famous songs of the moisture of the surrounding air is not high enough, especially at temperatures below 10C, which complicates its application to securable objects in the field and reduces the duration of the season anticorrosion works.
Problem to be solved in the framework of the present invention is to provide a moisture-curable air odnoupakovochnye polyurethane film-forming with long shelf life without irreversible changes in physico-chemical characteristics, with accelerated drying time and high resistance formed on the basis of the coatings to the effects of acidic corrosive environments.
The solution of the above problem is due to the fact that in contrast to the known compositions for coating the proposed formulation of dopolnitve which use tetrafunctional N,N-tetrapropylammonium, and as the organic solvent is ethyl acetate and/or butyl acetate, ethyl acetate and/or toluene with the following ratio of components, wt.%:
Polyoxypropylene with MM=3000-5000.E. 35,0-60,0
The polyisocyanate based on 4,4’-diphenylmethanediisocyanate 14,9-27,0
Organic solvent To 100
As polyoxypropylene use oligomers brands "Laprol-3003", "Laprol-4503", "Laprol-5003(TU 6-05-1513-76; THE 6-05-2033-87; THE 6-55-62-93). N,N-Tetrapropylammonium use of the brand “Supramol-294 (TU 6-05-1681-80). The polyisocyanate based on 4,4’-diphenylmethanediisocyanate has the trademark “Polyisocyanate” beyond 113-03-38-106-90. The ethyl acetate and butyl acetate are used according to GOST 22300-76, and toluene according to GOST 14710-78. The claimed range of ratios between the film-forming components are determined experimentally and are optimal from the point of view of achieving a positive effect. The use of solvents is more than 50 wt.% in the composition impractical, in particular, due to the inefficiency of its transportation. In addition, a large number of solvents containing, as a rule, moisture, consumes a significant share of polyiso is waiting for reagents, providing the optimal structure of the prepolymer. When the content of the solvent is less than 10% of the mixture of the initial components, the resulting composition is a viscous liquid, packing and further use by consumers is difficult because of its low processability. The recommended ratio between the reactants, the polyisocyanate and the polyol (a mixture of polyoxypropylene with N,N-tetrapropylammonium) provide optimal mechanical and protective properties of the resulting coatings. With a large content of MDI formed protective coating tough enough and do not have the necessary levels of flexibility. Fewer MDI slows the curing speed of the composition after its application to the protected surface. The claimed range of concentrations of N,N-tetrapropylammonium connected, on the one hand, ensuring a minimum sound duration of drying of the coating, especially at low temperatures, and on the other hand, ensuring their high stability towards acidic aggressive environments. In addition, the contents of this reagent in the composition of more than 3% neselesoobraznosti the proposed formulation with a known film-forming composition of the prototype allows to conclude that it conforms to the criterion “novelty”, as in this case contains a new combination of ingredients in the new proportions.
“Inventive step” of the present invention is illustrated in the foregoing lies in the fact that the additional introduction in the composition of low molecular weight polyol is N,N-tetrapropylammonium led to expected to accelerate curing of the composition due to its greater functionality and lower molecular weight than polyoxypropyleneamine, but also to non-obvious effect is the inhibition of the corrosion of the protected metal surfaces in acidic environments, while maintaining high physical-mechanical properties of coatings, which cannot be predicted in advance. The proposed composition, as the composition of the prototype can be made of industrially produced materials on standard chemical equipment. This allows to make a conclusion on the conformity of the proposed technical solution the criterion of “industrial applicability”.
Technical essence and benefits of the proposed structure are illustrated in the following examples.
Example 1 (the prototype)
In a reactor with a stirrer and reflux condenser load is the boiling point of the solvent (75-80C) and incubated in this mode to achieve the NCO-groups in the finished film-forming at the level of 10-12%. The composition is given in table. 1, and its characteristics is given in tab. 2. As sample material for all kinds of tests, in addition to elasticity in bending, used low carbon steel type Art.3, 08 KP, 08 SS with a sheet thickness of 0.8-1.0 mm surface Preparation of samples for testing were performed in accordance with GOST 8832 and GOST 9.402. Preparation includes cleaning the surface with a solvent (acetone, white spirit, thinners NN 645, 646, 647, 648) and subsequent sandblasting. The roughness of the prepared surface by Rz=30-50 μm. Samples for testing elasticity in flexure has a thickness of 0.2-0.3 mm Samples of polymer films for testing physical and mechanical properties tensile prepared by curing compositions on Teflon plates; film thickness of 0.2-0.3 mm Anticorrosive processing of steel samples for testing were performed by means of a brush. The resulting coating was dried in natural conditions at a relative humidity of 70-90%. The thickness of the coating in all cases amounted to 60-80 microns. Before the test of physical mechanical properties of the samples kept at room temperature for at least 48 hours, and the protective properties of not less than 7 days. Drying time to degree 3 op and the impact was determined according to GOST 4765. The elasticity of the coating during bending was determined according to GOST 6806. Physico-mechanical characteristics of polymer films under tension was determined according to GOST 263. Viscosity of the film-forming was determined by viscometer VZ-246 with the nozzle diameter of 4 mm according to GOST 8420. Resistance to static action of corrosive liquid media (25% solution of sulfuric acid) was evaluated according to GOST 9.403 (method A) the visual condition of appearance and change the adhesion of the coatings.
The inventive film-forming synthesized similarly compositions prototype. N,N-Tetrapropylammonium was introduced into the reactor together with polyoxypropylene. The film-forming compositions are given in table. 1, and their characteristics and properties of the resulting coatings is given in tab. 2-4. Thus, as seen from the above data, the claimed formulation of polyurethane film-forming, compared with the composition of the prototype has a higher curing rate, and formed of the protective coating is more stable in acidic environments, while maintaining high mechanical characteristics. The manufacture of the compositions in proportions that do not meet the stated causes
Polyurethane film-forming to obtain a coating, comprising polyoxypropylene with molecular weight of 3000-5000.E., the polyisocyanate based on 4,4’-diphenylmethanediisocyanate and an organic solvent, characterized in that it further comprises N,N-tetrapropylammonium, and as the organic solvent is ethyl acetate and/or butyl acetate, ethyl acetate and/or toluene, with the following ratio of components, wt.%:
Polyoxypropylene with molecular weight of 3000-5000.E. 35,0-60,0
The polyisocyanate based on 4,4’-diphenylmethanediisocyanate 14,9-27,0
Organic solvent To 100