RU2407773C2 - Method of producing anticorrosion mastic based on asphalt-resin oligomers - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: anticorrosion mastic is obtained in a single process cycle. The process involves loading bitumen at 130°C. Technical sulphuric acid is then added for 1.5-2 hours at 130°C. Further, the product is stabilised at 150°C for 4 hours. Additives are then added - industrial oil, butyl rubber, thermoplastic elastomer - at 140°C. The components are continuously stirred after each process cycle for 60-180 minutes.

EFFECT: improved physical and chemical characteristics of the obtained anticorrosion mastic owing to improvement of its composition and optimisation of the production technology.

3 cl, 1 tbl, 1 ex

Description

The invention relates to the production of materials used to protect external steel surfaces from corrosion; isolation of oil, gas, product pipelines, pipelines for various purposes of underground laying; isolation of underground tanks; waterproofing concrete and stone surfaces; as well as a binder in road construction and repair material for isolating damage to the main insulation of pipelines.

As you know, oil is a source for the production of motor fuels, oils, lubricants, as well as boiler and furnace fuel (fuel oil), building materials (bitumen, tar, asphalt). Bitumen is one of the final products of oil refining according to the fuel-oil variant. Bitumen has moderate hydrophobicity, atmospheric resistance, solubility in organic solvents, increased deformability, and the ability to soften when heated until completely melted. These properties have led to the use of bitumen for the production of modern anti-corrosion materials.

Modern anticorrosive protective materials must ensure the protection of pipelines for the entire period of their operation. Currently, one of the main directions of the production of protective coatings is the enrichment of bitumen with fillers and modifying additives, which contribute to increasing the physicochemical and anticorrosion properties of the compositions. The variety of chemical nature of such additives determines the variety of methods for producing protective coatings based on bitumen.

A known method of producing bitumen-polymer material [1], consisting of bitumen, rubber, sulfur compounds and hydroxyethylated alkyl phenol, which involves mixing petroleum bitumen with a solution of rubber SKEPT in an oil solvent and / or fuel oil. With, undoubtedly, the high protective properties of this material, its disadvantages are:

1. Low safety of the technological process of obtaining this material;

2. Additional safety requirements when using finished products;

3. Low ductility, leading to a decrease in the mechanical properties of the coating during further operation.

A known method for producing composite mastic [2], in which, along with the dissolution of the individual components in a solvent, operations such as oxidation by blowing with air at 160-200 ° C and vulcanization of the mixture at 145-155 ° C with subsequent mixing of the components are provided. The disadvantages of this method are:

1. The complexity of the used technological equipment;

2. A large number of heterogeneous operations;

3. A wide range of process temperatures;

4. The destruction of the starting substances;

5. The complexity of quality control of the final product.

A known method of producing an insulating bitumen-polymer mastic, consisting of a mixture of bitumen BND-60/90 and BNI-4 or BN-70/30, divinyl styrene thermoplastic elastomer, plasticizer, filler, petroleum resin, adhesive additives and modifiers [3]. A method of producing mastic having such a composition consists of preparing a mixture of road and insulating or building bitumen, followed by its dehydration. Then the mixture is heated to 165-175 ° C, mixed and the remaining components of the mastic are introduced. The advantage of mastic is a fairly high quality of corrosion protection of underground pipelines. However, mastic materials obtained by this method have the following disadvantages:

1. Low adhesion at low temperatures, which affects the quality of the coating during application and its operation in the future;

2. High permeability to corrosive substances of the environment;

3. The decrease in the stability of physico-chemical characteristics during operation of the coating;

4. The application of the mastic with the melt requires high temperatures, which leads to the destruction of the constituent components.

A known method of producing a bitumen-polymer composition consisting of bitumen, polymer, mineral filler, oil [4]. The disadvantage of this method is a rather strict restriction on the size of the crushed polymer particles, a difficult dosage in the extruder, where each component has its own loading speed, despite the fact that all components of the composition are loaded into the extruder at the same time.

A known method for producing bitumen-polymer materials, the fundamental difference from which from all of the above methods is a simplified method for producing bitumen-polymer materials, which consists in a one-stage process [5]. The disadvantages of the anticorrosive material made in a known manner are:

1. Low softening point;

2. Limited temperature range of application and operation;

3. Low quality of the final product.

Common disadvantages of bitumen-polymer compositions for the complex of protective properties are:

1. Low adhesion at low temperatures, which affects the quality of the coating during application and its operation in the future;

2. High permeability to corrosive substances of the environment;

3. The decrease in the stability of physico-chemical characteristics during operation of the coating;

4. Low ductility, leading to low mechanical properties of the coating in the future;

5. Low safety of some technological processes for producing bituminous mastics and additional safety requirements when using this product;

6. The complexity of the technological equipment used for some types of bitumen mastics;

7. The application of the mastic with the melt requires high temperatures, which leads to the destruction of the constituent components;

8. Separation of bitumen-polymer mastics into individual components during prolonged storage in hot form.

Compounds based on asphalt-resinous oligomers, which combine the positive properties of polymers and bitumen, have higher protective properties: mechanical strength and a fairly high ductility with higher adhesion to metal than bitumen.

The closest in technical essence to the proposed method is a method for producing anti-corrosion material [6, prototype]. The essence of the known method for producing anticorrosive material consists in the interaction of asphalt deasphalting tar tar with propane with a heavy tar of bottoms from the production of isoprene from the regeneration stage of dimethylformamide and sulfuric acid. The method of obtaining includes three stages:

Stage I (210 min).

1. The loading of asphalt deasphalting tar with propane (or bitumen) at a temperature of 90 ° C.

2. Submission to the reactor of heavy resin at a temperature of 90 ° C for 30 minutes

3. Stirring - 30 minutes

4. The supply of sulfuric acid - 180 min at a temperature of not more than 120-125 ° C.

Stage II (240 min).

1. Stirring and raising the temperature to 150 ° C.

2. Stirring at a temperature of 150 ° C.

Stage III (240 min).

1. Stirring and raising the temperature to 160 ° C.

2. Stirring and stabilization of the product at a temperature of 160 ° C - 240 min.

3. Cooling to 120 ° C and draining the finished product.

A significant disadvantage of the prototype method is that the set of operational characteristics of the anticorrosive material obtained in this way does not correspond to the characteristics of the finished product. In addition, a wide range of operating temperatures (from 90 ° C to 160 ° C) determines the high energy intensity of the process.

The asphalt-resinous compounds obtained in this way, in comparison with bitumen-polymer materials, have better anti-corrosion properties, but are limited in the range of application due to:

1. High temperature fragility;

2. Low adhesion at low temperatures.

These restrictions do not allow the widespread use of asphalt-resinous compounds individually, as an anticorrosive material. This product can be used as the basis for mastics with the necessary properties.

An object of the invention is to eliminate the disadvantages of the anticorrosive material of the prototype and to improve the physicochemical characteristics of the obtained anticorrosive mastic by improving its composition and optimizing the technology for producing these compounds.

The stated technical problem is achieved due to the fact that the method of obtaining anticorrosive mastic, performed in a single technological cycle, includes loading the starting components, dripping technical sulfuric acid, stabilizing the product, introducing additives with constant stirring after each operation of the cycle. In order to improve the physico-chemical characteristics of the resulting mastic, modifying additives are additionally introduced into its composition: technical oil, butyl rubber and thermoplastic elastomer.

The proposed method for producing mastic based on asphalt-resinous oligomers is as follows:

Stage I - Obtaining asphalt-resinous oligomers:

1. The loading of bitumen (or asphalt deasphalting tar tar with propane) - 72-80% of the total mass of the loaded raw materials and heavy resin (CORD) - 2-3% of the total mass of the loaded raw materials in the mixer at a temperature of 130 ° C.

2. Stirring - 1-1.5 hours

3. Dripping in technical sulfuric acid - 4-6% of the total mass of the loaded raw materials - 1.5-2 hours at a temperature of 130 ° C.

4. Stirring - 1 hour

5. Product quality control.

6. Product stabilization:

- Rise of temperature to 150 ° C.

- Stirring - 4 hours

7. Product quality control.

8. Drain of the intermediate product (if necessary, obtain a semi-finished product).

Stage II - obtaining anticorrosive mastic based on asphalt-resinous oligomers:

9. The introduction of additives at a temperature of 140 ° C:

- Technical oil - 9-11%;

- A mixture of rubbed butyl rubber - 1-2% and thermoplastic elastomer 4-6% for 3 hours

10. Stirring - 3 hours at a temperature of 140 ° C.

11. Drain the finished product into containers or into boilers for the further manufacture of rolled mastic materials.

The essence of the invention is to optimize the method of obtaining anticorrosive mastics, excluding extreme temperature conditions, uniform heating of the prepared mastic provides:

1. The homogeneity of the composition;

2. Elimination of possible destruction of added additives due to excessive heating.

Introduction to the method of producing mastic two additional stages of quality control of the resulting product allows you to get mastic (as a semi-finished product, and the finished product) with the required physico-chemical and operational characteristics.

A significant difference from the prototype is the introduction into the composition of the mastic modifying additives - technical oil, butyl rubber and thermoplastic elastomer. Butyl rubber and thermoplastic elastomer are used as a mixture, with butyl rubber being crushed beforehand. The introduction of modifying additives provides increased elasticity, strength, adhesion to the surface to be protected, reduces the brittleness temperature, and, therefore, in the complex, all of the above acquired properties increase the protective anticorrosion characteristics, the service life of the mastic and the anticorrosive layer based on mastic.

To obtain anticorrosive mastic, bitumen is used, preferably with a softening temperature according to the KiS method from 60 to 90 ° C. Instead of bitumen, it is possible to use asphalt deasphalting tar with propane. As a heavy resin, the bottom residue of isoprene production of the dimethylformamide - CORD regeneration stage is used. Technical sulfuric acid is used as sulfuric acid, preferably in a concentration of 65 to 95%. As technical oil can be used rapeseed oil according to GOST 8988-2002 [7], industrial oils according to GOST 20799-88 [8].

As thermoplastic elastomer can be used thermoplastic elastomer DST according to TU 38.40327-98 manufactured by JSC "Voronezhsintezkauchuk" [9]. This is a branched block copolymer based on styrene and butadiene with the content of bound styrene. Thermoelastoplast DST is used as a modifier of bitumen for the manufacture of roofing materials, in the manufacture of shoe compositions, adhesives, coatings, as well as for the modification of plastics.

This process is designed to use a reactor of up to 10 cubic meters. m. With a decrease in reactor volume, the process time decreases.

An example implementation of the proposed method.

1. The loading of bitumen (or asphalt deasphalting tar tar with propane) - 72-80% of the total mass of the loaded raw materials and heavy resin (CORD) - 2-3% of the total mass of the loaded raw materials in the mixer at a temperature of 130 ° C.

2. Stirring - 1-1.5 hours

3. Dripping in technical sulfuric acid - 4-6% of the total mass of the loaded raw materials - 1.5-2 hours at a temperature of 130 ° C.

4. Stirring - 1 hour

5. Product quality control.

6. Product stabilization:

- Rise of temperature to 150 ° C.

- Stirring - 4 hours

7. Product quality control.

8. Drain of the intermediate product (if necessary, obtain a semi-finished product).

9. The introduction of additives at a temperature of 140 ° C:

- Technical oil (rapeseed or industrial) - 9-11%;

- A mixture of rubbed butyl rubber - 1-2% and thermoplastic elastomer (for example, DST 30R-01) 4-6% for 3 hours

10. Stirring - 3 hours at a temperature of 140 ° C.

11. Drain the finished product into containers or into boilers for the further manufacture of rolled mastic materials.

The application of the proposed method for the production of anticorrosive mastic allowed:

1. Get mastic with significantly better physico-chemical and operational characteristics;

2. Optimize processes;

3. Reduce energy costs;

4. Reduce the cost of the product.

The operational characteristics of the finished product obtained according to the example shown in the table. The tests were carried out in accordance with the requirements of GOST R 51164-98, TU 2293-006-94274904-2007 (Act No. 227 of testing the protective coating of steel pipes dated 11.12.2007).

Product performance Name of indicator Norm Fact 1 Appearance Homogeneous mass of black color without visible foreign inclusions. Compliant 2 Softening point, ° С 70-90 70-90 3 The depth of penetration of the needle, 0.1 mm, at a temperature of 25 ° C, not less than 35.0 64.0 4 Adhesion to steel at a temperature of 20 ° С, MPa / sq.m, not less 0.2 0.35

The quality of the anticorrosive mastic made by the proposed method meets the requirements of regulatory and technical documentation for protective coatings of the outer surface of wire pipes.

As the tests showed, the obtained mastic based on asphalt-resinous oligomers of the above composition by the proposed method exceeds the prototype in all physicochemical parameters. With a slight increase in the total production time of the mastic, the preparation time for the semi-finished product - similar to the prototype - is significantly reduced. The energy consumption of production is reduced by narrowing the range of operating temperatures (from 130 ° C to 150 ° C), material costs, and, consequently, the cost of anticorrosive mastic.

Thus, obtaining the proposed method of mastic based on asphalt-resinous oligomers of the claimed composition allows to obtain a high-quality product that meets the requirements of coatings used to protect the external surfaces of main and oil, gas, product pipelines and pipelines for various purposes and tanks from corrosion.

Technological regulations have been developed for the method of obtaining anticorrosive mastic, and an experimental batch of mastic has been produced. Corrosion-resistant mastic based on asphalt-resinous compounds has been successfully tested at various pipeline transport facilities in Russia.

Information sources

1. RF patent 2248381 with priority from 04/09/03, cl. 7 C08L 95/00 “Bitumen-polymer material and method for its preparation” / Zaripov R.K., Makhmutov A.A., Makhmutov M.A., Kuzmichev S.P., Khazipov R.Z., Gorbachev N.G. ., Kosorenkov D.I., Lebedev I.N.

2. RF patent 2218369 with priority from 01/09/01, cl. 7 C08L 95/00, C08L 17/00 “Method for producing composite mastic” / Schelkov F.L., Khazipov R.Z., Gorbachev N.G., Kosorenkov D.I., Lebedev I.N., Lebedev S. N.

3. RF patent 2241897 with priority of 02/10/03, cl. 7 F16L 58/12, C08L 95/00 “Insulating bitumen-polymer mastic and a method for its manufacture” / Stepanov V.F., Gorbacheva R.I., Nechinyeny V.A., Brekhov P.P.

4. RF patent 2218370 with priority dated 10.12.03, cl. 7 C08L 95/00 “Method for the production of bitumen-polymer compositions” / Smirnykh A.A., Shabanov I.E.

5. RF patent 2265033 with priority dated 12/08/03, cl. 7 C08L 95/00 “Method for the production of bitumen-polymer materials” / Takhautdinov Sh.F., Schelkov F.L., Khazipov R.Z., Gorbachev N.G., Alfetonov R.A., Nadyrshin R.G., Kosorenkov D.I., Lebedev I.N.

6. RF patent 2074224 with priority of 01/21/94, cl. 6 С10С 3/02 “Method for the production of anticorrosive material” / I.F. Gladkikh, S.V. Pestrikov, N.M. Cherkasov, I.U. Subaev, B.C. Alekseev (prototype).

7. GOST 8988-2002. Rapeseed oil. Technical conditions

8. GOST 20799-88. Industrial oils. Technical conditions

9. http://www.vrnsk.ru/?range=dst-30r-01.

Claims (3)

1. A method of producing anticorrosive mastic by reacting bitumen with a heavy resin (bottom residue of isoprene production at the stage of regeneration of dimethylformamide) and sulfuric acid, characterized in that the process is carried out in a single technological cycle with the loading of bitumen at a temperature of 130 ° C, by dropping technical sulfuric acid 1.5 -2 hours at a temperature of 130 ° C, stabilization of the product at 150 ° C for 4 hours, the introduction of additives - technical oil, butyl rubber, thermoplastic elastomer - at a temperature of 140 ° C, with constant stirring after each op a cycle of 60 to 180 minutes, and the process is carried out in the following ratio of components, wt.%:
Bitumen 72-80 Heavy resin 2-3 Technical sulfuric acid 4-6 Technical oil 9-11 Butyl rubber 1-2 Thermoelastoplast 4-6 2. The method of obtaining anticorrosive mastic according to claim 1, characterized in that the technological cycle additionally introduces a double quality control of the resulting mastic and provides the possibility of draining the intermediate product (semi-finished product). 3. The method of obtaining anticorrosive mastic according to claim 1, characterized in that the concentration of technical sulfuric acid is from 65 to 95%.