PL154449B1 - Anticorrosive and antidepositing agent for protection ofmetallic surfaces,in particular those of carbon steel,cooper and its alloys - Google Patents

Description

REPUBLIC POLAND PATENT DESCRIPTION 154 449 Int. Cl. ⁵ C23F 11/10 ΪΖΠΕΙδϊΗ 8 fi h LH Additional patent to patent no - Reported: 87 12 29 (P. 269770) Priority - OFFICE PATENT Ticket announced: 89 at 7 10 RP Patent description published: 1991 11 29

Creators of the invention: Andrzej Kotliński, Jolanta Jurek, Bożenna Dalewska, Józef Mieluch

The holder of the patent: Industrial Chemistry Research Institute, Warsaw (Poland)

ANTI-CORROSIVE AND ANTI-FOSS AGENT FOR THE PROTECTION, ESPECIALLY, OF CARBON STEEL, COPPER AND ITS ALLOYS

The subject of the invention is an anticorrosive and anti-fouling agent intended for the protection of circulating, open and closed, water cooling and heating systems as well as devices and installations, especially made of carbon steel, copper and its alloys, in contact with industrial waters.

Corrosive processes and deposition of sediments in industrial, water-based heating and cooling systems cause disturbances in the operation of these systems and premature destruction of installations and devices in contact with water. As a result of corrosion processes, apart from destroying metal elements, the system is contaminated with corrosion products in the form of suspensions and sediments deposited on the surface of the installation. Deposits are also formed by the decomposition of calcium and magnesium bicarbonates in the water. The formed insoluble carbonates are mainly deposited on the surface of the heat exchangers. Another source of sludge contaminating the surface of the installation are microorganisms whose live and dead colonies adhere to the surface of the installation, forming together with mineral sediments from the water so-called hydrobiological deposits. The corrosive, mineral and hydrological sediments deposited on the surface of the installation stimulate corrosion processes due to the occurrence of the so-called sub-sludge corrosion, impede water flow and worsen heat transfer, which causes significant losses in the power industry.

Known from the Polish patent description No. 122,499, the agent preventing the formation of deposits on the walls of the reactors is an aqueous solution of polyacrylamide with a concentration of 0.1% by weight.

Polish patent description No. 141 017 describes an agent for protecting against corrosion and formation of dense deposits of surfaces made of iron alloys, copper and its alloys in closed water systems, which contains sodium nitrite, sodium tetraborate, 2-mercaptobenzothiazole and acid 1-hydroxyethylidene-1,1-diphosphonic acid. this measure, due to the zał.ecan ^{A D A D} Pri and the ^EC wearing ^a Ca ^s k 9 ^{g /} m and ^P tol <syczność s ^p owodowan ^thereby azo so ^you n ^d u ^can only be used in aqueous closed circuits.

154 449

154 449

Polish patent specification No. 136 710 describes an anti-corrosive, anti-fouling and biocidal agent. It consists of nitrile-trimethylphosphilic acid or its soluble salts, at least one polyphoxy-SiWtgo acid or its soluble salts, or its anhydrides and organic or inorganic zinc compounds, this agent protects carbon steel against corrosion and deposits in busy and open water systems heating and cooling.

Unexpectedly, it turned out that the replacement of a part of the nitritrimethylphosphonic acid with 1-hydrocxettlidene, 1-diphosphonic acid, the addition of an ethyl acrylate copolymer with other acrylic monomers, or polyacryoamide or polyteooamine and the addition of a compound from the azole group, not only caused in the inhibitor, but also reduced the corrosion rate many times over compared to the agent of Patent Specification No. 136,710.

The essence of the present invention consists in the fact that the agent containing: niOryltrimethylfssfonsoy acid or its soluble salts, organic or inorganic zinc compounds, at least one poHkaΓboxySoot acid or its soluble salts, or its anoxides, consists of: 1-hydroxyethylidene-1,1-difssSooic acid in a weight ratio of 0.5: 1 to 4.5: 1, respectively, or mixtures of their soluble salts, 1-40% by weight of ethyl acrylate copolymer with other acrylic and / or

0.5 - 15% by weight of polyacrylamide ίΑυό 2 - 40% by weight of polyetesoamint, 5 - 40% by weight of a compound from the azole group and 6 - 25% by weight, based on zinc, of zinc salts and 3 - 30% by weight of polycabboxySowtgs or its anhydride or a soluble salt thereof or a mixture of these.

It is preferable to use 2-mercaptobeeazole or its salts, or a benzostiazole or tolylstriazole as the azole compound.

It has been found that it is advantageous to use a mixture of doua-carboxylic acids which are waste from the production of adipic acid as the polycarboxylic acid.

the agent according to the invention has very good lateral and transient properties. this agent in water heating or cooling systems and other devices operating in water environments effectively inhibits the corrosion rate, especially of carbon steel and copper and its alloys, and prevents the deposition of corrosive, carbonate and hydrobiological deposits on the surface of pipes and other devices of the water installation and on the surface heat exchangers, maintaining the efficient operation of these systems for many years. The use of this measure does not require additional water treatment.

The corrosion rate of steel with the use of the agent according to the invention is, depending on its composition, 4 - 400 times lower compared to the corrosion rate with the use of the agent according to patent 136 710. Due to such a significant reduction in the rate of corrosion, the effectiveness of anti-corrosion and anti-fouling protection of steel is close to 100% .

The subject of the invention is presented in the following examples:

Example I. Composition of the agent: 29.0 wt.%. % of nitrilotrimethylphosphate acid, 6.5 wt. % 1-hydroxyethylidene-1,1-diphosphonic acid, 16.1 wt. polyetheramines (average molecular weight M = 3000) with the formula:

r-EtE- (O-PrOH-O-EtE) _ra -O-PrOH-N-PrOH-O-Jn

AND

EtDH where:

m = 1,

-EtE- = -CH2CH2-O-CH2CH2-,

-PrOH- = -CH2CHCH2-,

AND

OH

-EtOH

-CH2CH2OH,

154 449

12.1 wt.% % (as zinc) of zinc sulphate, 6.1 wt. % glutaric acid, 3.6 wt. % adipic acid, 2.4 wt.% succinic acid, 24.2 wt.% 2-mercaptobenzothiazo.

Env ^{piece is} added in about ^{dy d} of the model comprising [eq / m ³ J 9.0 - CaCl ^ ^4, 5 - over sodium, ^4,0 - N ^aHCOj at ^{6, 2 "10} \ by weight. ^Sk u-teczność protection ^yp rzeciw Oroz ^{y k} and ^p jnej rzeci.wosadowej compared to carbon steel and brass St3s M70 were analyzed by gravimetric at 293 K and 333 K. The following results were obtained:

Material Temp. Lk ^] Time fh ^J Speed Protection efficiency corrosion £ mm / year J. sediment deposition [g ^/ m ^2d] against- corrosive [*] against- sedimentary [*] steel 293 96 0.0001 0.003 100.0 100.0 St3s 333 260 0.0088 0.025 97.2 98.1 Brass 293 96 0.0023 0.201 85.5 77.2 M70 3 ^ 3 260 0.0024 0.020 88.5 82.2

Example II. Agent composition: 41.7 wt.% % nitrilotrimethylphosphonic acid, 9.3 wt. % 1-hydroxyethylidene-1,1-diphosphonic acid, 2.8 wt. % of polyacrylamide (with an average molecular weight of 2 min - 4 min), 17.4 wt. % (as zinc) of zinc sulfate, 8.6 wt. % glutaric acid, 5.2 wt. % of adipic acid, 3.5 wt. % succinic acid, 11.5 wt. ² -mer ^k a ^{b pt} of azo enzo ^{t l} u. ^{S t} measure en ^d o ^<d Jano of beef ^dy i ^k in Example I at ^{4, 3} * 1 ⁰ * ^3% wa ^g of these. The effectiveness of the agent was tested as in Example 1 and the following results were obtained:

Material Temp. [k] Time fh] Speed Protection efficiency corrosion Jmm / ro ^kJ sediment deposition [g ^/ m ^2d J against- corrosive KI against- sedimentary ['] steel 293 96 0.0003 0.007 99.8 99.9 St3s 333 260 0.0053 0.024 98.3 98.2 Brass 293 96 0.0038 0.301 76.1 65.8 M70 333 260 0.0029 0.088 86.1 51.8

Example III. Composition of the agent: 11.5% by weight nitrilotrimethylphosphonic acid, 23.1 wt. % 1-hydroxyethylidene-1,1-diphosphonic acid, 7.7 wt. % of ethyl acrylate copolymer with other acrylic monomers (as 40% water emulsion), 14.4 wt. % (as zinc) of zinc sulfate, 7.2 wt. % glutaric acid, 4.3 wt. % of adipic acid, 2.9 wt. % succinic acid, 28.9 wt. 2-mercaptobenzothiazole. This measure is added to water as in Example I and quan ^{c 5 2} "10% ** wa ^y 0w ^g C ^h. Sk ^ ^ communications ^COG measure was tested as in Ex ^I and ^y places give us ^the following ^{results, and} CE:

154 449

Material Temp. [· Κ] Time [h. j Speed Protection efficiency corrosion £ mm ^/ year ^J deposition of sediments [g ^ d ^J against- corrosive hJ against- sedimentary ['] steel 293 96 0.0002 0.005 99.9 100.0 St3s 333 260 0.0060 0.025 98.1 98.1 Brass 293 96 0.0027 0.300 83.0 65.8 M70 333 260 0.0029 0.025 86.1 86.3

Claims (3)

Patent claims 1.Anti-corrosion and anti-fouling agent for the protection of, in particular, carbon steel, copper and its alloys, containing nitrilotri-methylphosphonic acid or its soluble salts, organic or inorganic zinc compounds, at least one polycarboxylic acid or its soluble salts, or its anhydrides, characterized by consisting of: 10 - 65¾ by weight of a mixture of nitrilotrimethylphosphonic acid with 1-hydroxyethylidene-1,1-diphosphonic acid in a weight ratio of 0.5: 1 to 4.5: 1, respectively, or a mixture of their soluble salts, 1 - 40% by weight of acrylate copolymer of ethyl with other acrylic monomers and / or 0.5 - 15% by weight of polyacrylamide and / or 2 - 40% by weight of polyether amine, 5 - 40% by weight of a compound from the azole group and 6 - 25% by weight, based on zinc, of zinc salts and 3 - 30% by weight of a polycarboxylic acid or its anhydride or a soluble salt thereof or mixtures thereof. 2. an agent according to claim The compound of claim 1, wherein the azole compound is 2-mercaptobenzothiazole or its salts, or benzotriazole or tolyltriazole. 3. The agent according to claim The process of claim 1, characterized in that it contains a mixture of glutaric, adipic and succinic acids waste from the production of adipic acid. Department of Publishing of the UP RP. Circulation 100 copies. Price PLN 3,000