HU198955B - Petroleum-soluble polyethylene-based composition - Google Patents

Abstract

An anticorrosive material consisting of polyethylene plasticized by a mineral oil and containing an oil-solvable corrosion inhibitor: a) a contact corrosion inhibitor: a sulphonated or nitrated mineral oil or the product of neutralization of the sulphonated or nitrated mineral oil by the alkali or the calcium hydroxide, or the product of neutralization of the sulphonated mineral oil by the urea, or the vat residues of the distillation of synthetic or natural fatty acids, or the products of condensation of said vat residues with organic amines, or the product of condensation of alkenyl-amber anhydride and the urea, or b) a volatile corrosion inhibitor: the salt of the cyclo- or dicyclohexylamine and an organic acid, or a heteroalkylised lower amine, or c) a mixture of the contact and volatile corrosion inhibitors; with the following relationship of the components of the anticorrosive material in percent by mass: mineral oil 20-45, oil-solvable corrosion inhibitor: 2-50, polyethylene: the balance up to 100.

Description

FIELD OF THE INVENTION The present invention relates to a composition for corrosion protection of metals, soluble in mineral oil and based on polymer, which combines the ability of polymers to lock and the ability of corrosion inhibitors to chemically reduce corrosion processes. This composition can be used for the manufacture of sealing components, such as sealing rings, sealing rings and sealing sheets, easily removable anti-corrosion coatings, and film and corrosion resistant packaging materials, which can be used for the preservation and packaging of metal products.

Polymer films and coatings of a few mm thickness do not provide an impermeable barrier against diffusion of water, oxygen and electrolytes. The protective effect can be significantly increased when the polymeric materials are combined with corrosion inhibitors.

By mixing polymer solutions or powders with corrosion inhibitors compatible with the polymeric base material and subsequent heat treatment, cellulose ester, polyacetal and polyester-based corrosion-resistant films and coatings can be prepared. Thus, for example, a corrosion-resistant material containing a mixture of an amine nitrate and an ammonium salt of an aliphatic carboxylic acid is known (U.S. Patent No. 3,462,329).

Known corrosion-resistant materials have the disadvantage that they use expensive polymeric materials and can only be used to protect certain products.

Japanese Patent Application No. 49-21,223 discloses a corrosion-resistant packaging material which is a snow-stable inhibitor of a mixture of polyethylene or other chemically resistant polyolefin with an inorganic mixture of alpha-dicyclohexylamine salts, betacyclohexylammonium nitrite and nitrosodicyclohexylamine. by extrusion.

It has the disadvantage that the inhibitor melts during the preparation and thus the protective effect of the product is low, and that some of the inhibitor used is irreversibly penetrated into the polymer film.

The corrosion behavior of polymeric materials containing the inhibitor is affected by the contact of the surface of the inhibitor and the material to be protected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a corrosion-resistant composition of a mixture of polyethylene and a corrosion inhibitor that provides controlled and time-stable release of the corrosion inhibitor on the surface of the product to be protected or inside the hermetic package. This increases the effect of the corrosion inhibitor and enhances the degree of protection.

The present invention relates to a petroleum-soluble corrosion inhibitor containing a mineral oil-soluble corrosion inhibitor, which is a petroleum-refined petroleum oil or a distillate of rectified petroleum oils,

(a) as a contact corrosion inhibitor

nitrated paraffinic petroleum refined petroleum or

petroleum oxidised with a calcium sulphonate solution, or

- sodium sulphonate obtained by the reaction of sulphonic acids with caustic soda in a sulphonylated oil distillate, or

- nitrated mineral oils neutralized with calcium hydroxide and concentrated with stearin, or

- salts of cyclohexylamine and C 7 -C 11 fatty acids, or

- distillation of fatty acids from cotton and fatty soap base, or

a condensation product of alkenyl butanedioic anhydride and urea, or

b) as a liquid corrosion inhibitor

- a salt of a technical fraction of dicyclohexylamine and a C 10-20 synthetic fatty acid, or

- the technical fraction of the secondary amines of the fatty acids and of the acrylonitrile of the formula (I):

R is CnH2n * i 'and n is 7-9, or

c) a mixture of a contact corrosion inhibitor and a liquid corrosion inhibitor, wherein the polyethylene may be low (S = 900-939 kg / m ³ ) or high (S = 949-959 kg / m ³ ) density and the amount of the components is petroleum 20-45 massX corrosion inhibitor 2-50 massX polyethylene 5-78 massX.

The corrosion-resistant composition of the present invention has a number of advantages. The corrosion inhibitor are chosen in a controllable manner and in time evenly down the surface of the protected material, or a hermetically sealed package interior space, which ensures high performance corrosion protection, is protected by a foil or a coating made of corrosion-resistant composition according to the invention steel corrosion rate is less than 10 ⁴ neutral conditions g / m ² hours. The physical-mechanical properties of the corrosion-resistant composition of the present invention can be set within wide limits and can be processed by any particular technology. They can be used, for example, to protect local corrosion of metal parts used as sealants, as packaging films, to protect metal products against atmospheric corrosion during transport and storage and as a corrosion-resistant composition (carrier for liquid corrosion inhibitors) enclosed within airtight packaging.

The corrosion-resistant composition of the present invention is based on a gel polyethylene liquid hydrocarbon softener system. A mixture of these with an oil-soluble inhibitor at a temperature of 115-230 ° C (temperature range of polyethylene melting

EN 198955 Β, at which the thermooxidative decomposition of polyethylene begins) is transformed into a homogeneous solution. This is cooled to 90-150 ° C to give an amorphous mixture in which the high viscosity of the solution prevents complete separation of the phases. The phase separation is localized to the micro-sites determined by the formation of the polyethylene molecules, which results in the formation of a polymeric matrix of pores filled with a liquid, small molecule filler (solution of the inhibitor in mineral oil). The above spontaneous separation of the liquid phase during the relaxation process is called syneresis.

The pore size of the polymeric matrix will depend on the composition of the corrosion-resistant structural material of the invention and the residence time at the temperature of the amorphous mixture, and will generally be in the range of 10-30 pra. An essential condition for transporting the inhibitor dissolved in the plasticizer by the synthesis mechanism to the surface of the product to be protected is the presence of the above-mentioned interconnected pores. When using a contact corrosion inhibitor, the only way to transport the inhibitor to the surface of the product to be protected is through the above synthesis, while the liquid inhibitor is transported in the polymer matrix by migration and diffusion.

The interconnected pores reduce the strength and deformability of the material. Based on the physical-mechanical properties of the plasticized polyethylene filled with corrosion inhibitor, it can be used as a sealing material and packaging material if the polyethylene content 35 is greater than 50% by weight.

The upper and lower limits of the components are determined by the optimum combination of physical-mechanical properties and corrosion. 40

The lower limit of the amount of plasticizer (20% by weight) is due to the fact that the synthesis process must take place, whereas the upper limit (45% by weight) is determined by the desired physical-mechanical properties. (For example, for packaging material 45, the tensile strength should be at least 10 MPa and the bending strength should be at least 400%.)

The lower (2 wt%) and upper limits (50 to 50 wt%) of the amount of oil soluble inhibitor are determined by the concentration of inhibitor to be achieved on the metal surface to be protected, the degree of inhibitory effect and the transport of the inhibitor to the surface to be protected. The upper limit of the amount of inhibitor is also influenced by economic considerations and the desired physical-mechanical properties of the product.

In order to prepare the corrosion-resistant composition of the present invention, the oil-soluble corrosion inhibitor 60 is mixed in the plasticizer (mineral oil) until the inhibitor is completely dissolved. The resulting solution is mixed with polyethylene granules in any apparatus such as a drum. The resulting mixture is then melted and then processed by extrusion, casting, or melt immersion. Processing is generally carried out by spraying for sealant components and extruding the molten mixture for film.

Low density (900-939 kg / m ³ ) or high density (949-959 kg / m ³ ) polyethylene is used to prepare the corrosion resistant composition.

Preferably, the following mineral oils are used as a plasticizer for polyethylene:

(a) Refined petroleum oils of sweet petroleum, paraffinic or petroleum-free

density: 0.89 g / cm ³ (20 ° C), viscosity: 1.4x10-5 m ² / s (20 ° C) ash: up to 0.003%, acid number: 0.25 KOH / g, pour point: -30 "C, Flash point: 200 ° C (in a closed jar); (b) low sulfur petroleum refinates crude oil: density: 0.897 g / cm ³ (20 ° C), viscosity: 2.05xl0- ⁵ m / s (20 ° C) ash: up to 0.003%, acid number: . 0.03 mg KOH / g, pour point: -18 "C, Flash point: 250 ° C (in a closed jar); (c) clean mineral oil, density: 0.894 g / cm ³ (20 ° C), viscosity: 4.9x10-5 m ² / s (20 "C) 20 cSt (50 ° C) pour point: -45 ° C, Flash point: 163 ° C (open jar);

Preferred oil-soluble contact inhibitors based on sulfonylated or nitrated petroleum include:

A) Nitrated paraffin (10% w / w) concentrated petroleum refined oil, dark brown oily liquid, density: 0.96 g / cm ³ (20 ° C), viscosity: 1.00 x 10 -m ² / s (20 ° C),

3.0x10-5 m ² / s (100 ° C)

3.5% oxidized with organic solvents and solution

3.2-4.0xl0- ⁵ m ² / s (100 "C) and 0:04 mg KOH / g,

9%, organic content in organic solvents: mineral oil;

B) calcium sulfonet in petroleum, viscosity: acid number: ash content: in mineral oil;

C) Sodium sulphonate obtained by reaction of sulphonic acids and caustic soda in a sulphonylated oil distillate, density: 0.961 g / cm ³ (20 ° C), viscosity: 2.30 x ^{10 5} m ² / s (100 ° C), acid number: 0.04 mg KOH / g, ash content: 9%;

(D) Mineral oils, nitrated, calcium hydroxide neutralized and stearin-concentrated (10% by weight), black oily liquid, viscosity:

density:

ash:

1.00 x 10 * m ² / s (100 "Cl, 0.96 g / cm ³ (20 ° C),

4.6%;

EN 198955 D Soluble in mineral oil and organic solvents.

Preferred distillation residues of synthetic or natural fatty acids are:

El Cyclohexylaniline and C7-11 Synthetic Fatty Acid Salt (Cnlknt + 1COOC6H11NH2), pasty light brown, mp: -12 ° C, soluble in oil, petroleum, gasoline and acetone;

F) wool, and a distillation residue of bone fatty soap base fatty acid Jain, mainly consisting of higher molecular weight saturated and unsaturated fatty acids and contains a certain amount of detection of intact fat and fats and fatty acids, oxidation products of carbon number of the compound to 10 to 24, density: 0.90 + 0.85 g / cm ³ (20 ° C), viscosity: 6.5-7.0x10 * ⁵ m / s (50 ° C), acid number: 62 mg KOH / g, flash point 260 ° C (in an open crucible).

In addition, an effective contact corrosion inhibitor is the condensation product of alkenyl butanedioic anhydride and urea (hereinafter "G"), light brown liquid, density: 0.89 g / cm ³ (20 ° C), viscosity: 2.5x10 ⁵ m ² / s (50). ), Soluble in mineral oil and in organic solvents.

Examples of liquid oil-soluble corrosion inhibitors include:

H) Technical fraction of dicyclohexylamine (at least 43% by weight) and salts of synthetic C10-C20 fatty acids, paste product, density: 0.91-0.93 g / cin ³ (20 ° C), melting point: 15-20 ° C, in mineral oil and soluble in organic solvents, volatility 0.013 Pa (20 ° C);

I) A yellow to light brown liquid consisting mainly of a technical fraction of fatty acids and acrylonitrile secondary amines, which can be represented by the general formula (I)

R is Cnlkn.i, π is 7-9, density:

viscosity:

0.85 g / cm ³ (20 ° C), 6x10 ^-6 m ² / s (40 ° C), pour point: -40 ° C, boiling point: 190 ° C / 1.33 KPa, auto-ignition: 260 ° C, in mineral oil, alcohol, soluble in water and in organic solvents, volatility 13.3 Pa (20 ° C).

A mixture of a liquid corrosion inhibitor and a contact corrosion inhibitor is used to prepare a corrosion resistant composition for preservation and packaging.

Some specific formulations of the corrosion-resistant composition of the present invention are illustrated in the following examples, using as a comparative material the known corrosion-resistant material of Japanese Patent Application No. 49-21,223.

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Liquid inhibitor

The properties of the formulations I-XIV in Table 1 and the composition described in Japanese Patent Laid-Open No. 49-21,223 are shown in Table 2.

Tensile strength and flexural strength were measured on a tensile machine at a forming speed of 50 mm / min.

Corrosion tests were measured by an accelerated method, in which the polarization resistance (Rn) of a two-electrode apparatus connected to a sample of the material to be tested was measured in an electrolyte. For this purpose carbon electrodes containing 0.09-0.15% by weight of carbon steel were used. The effective electrode surface had a roughness Ra = = 0.4-0.5 µm, where the electrode surface without the measurement function was isolated with paraffin. The electrolyte used was 2N Na2SO4 solution. The corrosion rate is calculated using the following formula:

Kcew.

i = -1

S. Rp where Kcew = weight coefficient of corrosion dependent on electrolyte quality and concentration (Ohnvg / h).

n In Na2SO4, Kcew = 0.032.

Rp = polarization resistance (Ohm),

S = electrode charge surface (m ² ) (Zaschita metallow Nr, 6, Verlag Nauka, Moscow, 1982, pages 946-949).

Table 2

Together- item Tensile heart- Bending The corrosion-resistant steel has a corrosion rate of 10 ' ³ g / m ² h Strength, (MPa) (%) I 13.0 - 0:17 II 14.2 - 0:28 III 17.1 - 0.65 ARC 12.3 400 0:15 V 15.4 480 0.3 VI 12.8 550 0.6 VII 13.2 450 0.5 VIII 14.4 - 0:25 IX 11.1 - 0:31 X 12.2 - 0:44 XI 2.1 - 0:15 XII 3.5 - 0:11 XIII 3.3 - 0.2 XIV 3.7 - 0:25 49-21 223. s. Japan tailor. juice- writing 5.8 - 7.4

Table 2 shows that the physico-mechanical properties of the corrosion-resistant composition can be controlled over a wide range by changing the composition. The tensile stress ranges from values close to the strength of polyethylene (composition I-X) to strength similar to solid lubricant (composition XI-XIV). The bending strength was measured for low density polyethylene based formulations IV-VII, which are suitable for the preparation of films containing the inhibitor. The values obtained correspond to those expected for preserving and packaging materials.

Compositions I-X are suitable for the manufacture of sealant building blocks, whereby formulations IV-VII are also suitable for use in films containing inhibitors which are suitable for the preservation of metal products.

Compositions XI-XIV containing a large amount of liquid corrosion inhibitor can be recommended for the preparation of corrosion-resistant packaging.

In contrast to the corrosion-resistant composition of the present invention, the corrosion-resistant material of Japanese Patent Application No. 49-221223, based on its strength properties, can only be used as a corrosion-resistant packaging material, but not for the production of sealants and structural members.

According to the data in Table 2, the corrosion rate of the steel electrode coated with the film of the corrosion-resistant composition according to the invention (composition I-XIV) is 12-50 times lower than that of the corrosion-resistant material described in Japanese Patent No. 49-21,223.

When using the corrosion-resistant compositions of the present invention, the sealing of oil and gas equipment can be applied 1.5-2 times longer for pumps and sealing pipes and pump rods. Films made from the corrosion-resistant composition of the present invention can advantageously be used for the preservation of parts of various machines and apparatus by means of hermetic coating and vacuum forming. The hermetic packaging materials made from the corrosion-resistant composition of the present invention also protect the metal parts even when the packaging is made of a film that does not contain an inhibitor.

The corrosion-resistant composition of the present invention is distinguished by its general utility due to its high protective effect and wide range of physical-mechanical properties.

Claims (1)

Patent Claim Point Plasticized mineral oil, polyethylene-based corrosion resistant composition comprising a mineral oil-soluble corrosion inhibitor, characterized in that as mineral paraffinic or paraffinszegény derived from petroleum at -30 ° C pour point 0.89 g / ^cm3 density and 20 ° C for l, 4xl0 ⁵ m ² / s viscosity raffin7 -611 EN 198955 Β, raffinate from low sulfur petroleum with a pour point of -18 ° C, a density of 0,897 g / cm ³ and a viscosity of 2,5 x ¹⁰ * ⁵ m ² / s at 20 ° C, or a petroleum pitch of 0,894 g / cr raffinate with a density of ³ cm and a viscosity of 5 at 20 ° C of 4.9x10 * ⁵ m ² / s, and (a) as a contact corrosion inhibitor - nitrated petroleum refined nitrate with a density of 0,96 g / cm ³ and a viscosity of 1x10 ⁴ m ² / s at 20 ° C, or - petroleum oxidised with a calcium sulphonate solution having a viscosity of 3.2 to 4.0 x ¹⁰ · ⁵ m ² / s at 100 ° C, or - sodium sulphonate obtained by reaction of sulphonic acids with caustic soda at a density of 0,961 g / cm ³ and having a viscosity of 100 × ⁴ × 2,3 × 15 × ^{10 4} m ² / s or - 0.96 g / cm ³ density, 100 ° C lxlO ^'4 20 m ² / s viscosity nitrated neutralized with calcium hydroxide and thickened mineral oil stearin or pour point salt cyclohexylamine and 7-11 fatty acids -12 ° C 25 or ' - distillation residue of fatty acids of cotton and bone soap base of a density between 0,90 and 0,85 g / cm ³ and a viscosity of 5,5 to 7,0 χ ^{10 5} m ² / s at 50 ° C, or - a condensation product of alkenyl butanedioic anhydride and urea of a density of 0.89 g / cm ³ and a viscosity of 2.5 x ^{10 5} in ² / s at 50 ° C, or b) as a liquid corrosion inhibitor - a technical fraction of a salt of dicyclohexylamine and of C 10-20 synthetic fatty acids having a melting point of 15-20 ° C and a density of 0,91 to 0,93 g / cm ^3, or - a technical fraction of the secondary amines of fatty acids and acrylonitrile having a pour point of -40 ° C and a density of 0.85 g / cm ³ and a viscosity of 6.10 * ⁶ m ² / s at 40 ° C corresponding to formula (I), wherein R is C7H2O11 and n is 7-9 and comprises a contact corrosion inhibitor and a liquid corrosion inhibitor in a weight ratio of 1: 4-7: 1, with polyethylene 2 = 900-939 kg / m ³ or 2 = 949-959 kg / m 3 ^{It has a} density of ³ and the components are mineral oil 20-45% by weight corrosion inhibitor 2-50% by weight polyethylene 5-78% by weight.