PL153462B1 - Agent for protecting metals against corrosion or protecting paint coats against destructive environmental effects - Google Patents

Description

RZECZPOSPOLITA PATENT DESCRIPTION 153 462 POLAND

OFFICE

PATENT

RP

Additional patent to patent No. ---—

Reported: 86 07 31 (P. 260871)

Int. Cl.5 _C 2 _3F ι _{5 /} θθ C09D 5/08

Priority - READING

GENERAL

Application announced: 87 07 27

Patent description published: 1991 11 29

Creators of the invention: Jerzy Zawadzki, Jerzy Iwanow, Zbigniew Męczarski,

Andrzej Kozłowski, Robert Pudlikowski, Barbara Stankiewicz

Authorized by the patent: Institute of Precision Mechanics,

Warsaw Poland)

Λ

A product for the protection of metals against corrosion or for the protection of paint coatings against the action of harmful environmental factors

The subject of the invention is an agent for the protection of metals against corrosion or for the protection of lacquer coatings against the action of harmful environmental factors. The agent is used to protect metals and paint coatings, especially in the automotive industry.

Theological properties are one of the most important properties of the applied agent when using agents for the protection of metals and paint coatings. The appropriate theological properties facilitate the application of the agent by spraying with pneumatic devices, and the inadequate rheotogical properties make it difficult to apply by spraying. Inadequate rheotogical properties cause invisible drip of the center from vertical or inclined surfaces and the formation of characteristic stains "curtains on the protected surface. Inadequate rheotogical properties cause the coating to be unevenly thick: part of the surface is too thin, and part too thick. With inadequate rotational properties, particularly thin coatings are formed on the edges and on the ridges.

It is known to use ingredients that increase the viscosity of the agents, which reduce the dripping of protective formulations but make application difficult. When increasing the viscosity of the agent, the application with spraying devices, especially with automatic devices, is particularly difficult.

It is known to concentrate the agents by adding thixotroping mineral substances such as colloidal silica or bentonite. Agents thickened with a thixotroping component do not drip in thin layers from vertical or inclined surfaces, because their viscosity is significantly increased. On the other hand, the apparent viscosity of the agent containing a thixotroping additive, i.e. the viscosity of the agent flowing through conduits and pipes, in particular, is significantly lower than that of the agent at rest. After adding the thixotropic component to the formulation, the apparent viscosity will decrease as the shear stress increases, so the higher the flow velocity of the agent through the holes and conduits, the lower its apparent viscosity will be.

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The disadvantage of agents thickened with thixotroping components is the difficult availability of thixotroping components and their high price.

The viscosity of the known agent is dependent on the shear rate, but not sufficiently for conveying the agent through spray nozzles and delivery lines with very high flow rates.

It is known from the Polish patent specification No. 130,516 as a soft-coating temporary protection agent containing: waxes, bone tar, coumarone resin and hydrocarbon solvent.

There is known from the Polish patent description No. 111 807 a method of producing a corrosion protection agent. The method produces an agent containing calcium, zinc, magnesium soaps or mixtures thereof, still bottoms from processing animal bones, containing mainly a mixture of lactones, lactides and fatty acid condensation products in the amount of about 60-100 parts by weight and a hydrocarbon fraction with a boiling range of 150- 230 ° C in an amount of 5-25 parts by weight. The distillation residue from processing animal bones used for the production of soap has a density of 0.95-1.2 kg / dm3, a saponification number of 40-90, an ester number of 30-80 and an acid number of 15-60. Water is completely removed after the saponification process by evaporating it at temperatures above 100 ° C.

The known agent does not have thixotropic properties, but is a Newtonian liquid. The viscosity of the agent does not depend on the shear rate and is always e.g. 700 mPa.s at 20 ° C. The apparent viscosity at variable shear rates from 1 to 100 ^s_1 is also 700 mPa.s at 20 ° C. When applied to surfaces, especially vertical ones, such a measure drips, creating characteristic curtains.

A means for temporary protection of car chassis against the erosive action of mechanical factors and against the corrosive action of electrolyte solutions during operation is known from the Polish patent specification No. 74 121. The agent contains: 30-60 parts by weight of the bituminous product in the form of coal tar or tar pitch or petroleum asphalt or their mixture, preferably oxidized low viscosity petroleum alpha with a softening point of 60-110 ° C and penetration of 10-40 at 25 ° C, 2- 8 parts by weight of an ester-type wax substance of natural or synthetic origin based on macroparaffin or modified montan wax with a softening point of 60-90 ° C, an acid number of no more than 40, a saponification number of 30-140 and a molecular weight of 300-5000.1-5 parts by weight of metals of the II or III group of the periodic table, especially magnesium, zinc, barium or strontium fatty acids with a carbon chain length of 12-24 carbon atoms, 30-60 parts by weight of an organic solvent containing mainly aliphatic hydrocarbons, preferably boiling at 130-240 ° C, 1-5 parts by weight of xylene and / or tetrachlorethylene, 0.1-1 parts by weight of silicone oil and 0.1-12 parts by weight water.

This known preparation is a hard-coat anti-corrosion agent used on the chassis (trade name Bitex) based on such bituminous products which, when dry, provide a protective layer with considerable hardness and resistance to erosion (sand abrasion) and corrosion caused by aqueous salt solutions, which in winter are located on road surfaces. This agent contains a small amount of soaps of only about 1-5 wt%. and as ester-type waxes it typically contains lanolin in an amount of about 2-8 wt.%. Lanolin is an emulsifier (w / o type) and water forms a water-in-oil emulsion with lanolin. Most of the water introduced into the known preparation causes the formation of an emulsion of water in lanolin, and only a small part of it mixes with the remaining ingredients, contributing to the improvement of the Theological properties of Bitex. The improvement in rheological properties is clearly noticeable as the run-off and drip of the preparation from painted surfaces is reduced.

Due to the specific composition of the hard-coat composition as a whole, the improvement in the rheology of the known agent is neither sufficient nor permanent. Water in the composition of a known agent in a composition with the remaining components of Bitex and with a hydrocarbon solvent improves rheology for a short period of time and insufficiently for pneumatic or airless spraying with modern equipment. The viscosity of the formulation under shear stress is insufficiently reduced. The preparation obtains very favorable properties in comparison with the composition according to the Polish patent no. 71 207, which did not show thixotropic properties.

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However, this is not an improvement that would satisfy modern technical requirements. Requirements for this type of preparations are growing rapidly, and the desired directions of improving the properties are further lowering of viscosity in motion in the transport lines and elements of spraying devices, while increasing the resting viscosity, the increase of which eliminates the formation of stains on painted vertical surfaces and reduces drip.

A disadvantage of the known agent is, moreover, the instability of the improved rheological properties. When the agent is stored at ambient temperature, the water separates from the remaining mass of the formulation and the composition loses the already poor thixotropic properties.

The aim of the invention is to provide a soft-film agent that will have stable and enhanced thixotropic properties.

The aim of the invention is to develop an agent whose viscosity without thixotroping thickeners will depend to a much greater extent on the shear rate, so that the viscosity is low at high shear rates, and at low shear rates the viscosity increases, reaching the highest viscosity "at rest". , that is, at zero shear rate.

The aim of the invention is to develop an agent that at very high flow velocities - in nozzles and supply lines - will have a low apparent viscosity, and at rest will have a high viscosity, which will prevent dripping, the formation of stains and "curtains on vertical and inclined surfaces to be covered and the formation of thinner coatings on the edges and curves of the coated surfaces.

It turned out unexpectedly that the soft-film agent should be based on soaps of the II and III groups of the periodic table, which must constitute the majority of the active mass of the agent and, moreover, the agent must consist of hydrocarbon solvents with a specific aniline number of 50-85 ° C and meeting these two conditions, it must contain a small amount of water.

When these soft-film conditions are met according to the invention, the anti-corrosive agent obtains good and stable thixotropic properties consisting in a low apparent viscosity during flow in the conduits and a correspondingly high viscosity at rest, and these properties do not change during storage of the formulation.

The agent for the protection of metals against corrosion or for the protection of varnish coatings against the action of environmental damaging factors is made on the basis of a mixture of metal soaps of the II group of the periodic table of fatty acids with hydrocarbon solvents and, according to the essence of the invention, is characterized by the fact that it is a soap solution in an amount from 10 to 80 parts by weight and hydrocarbon solvents with an aniline number of 50 to 85 ° C in an amount of 20 to 90 parts by weight with water in an amount of 0.8 to 15 parts by weight.

Preferably, the composition comprises calcium and / or magnesium and / or zinc soaps of fatty acids in the waxes resulting from the oxidation of paraffin and / or fatty acids contained in the fatty acid still bottoms and / or its saponification products and / or polyanolin fatty acids. and / or waste fatty acids from the processing of plant or animal raw materials and / or technical fatty acids from the processing of plant or animal raw materials.

It is recommended that the agent contains hydrocarbon solvents boiling at temperatures ranging from 80 ° C to 250 ° C in the solution. It is preferred that the composition further comprises fatty acid esters and / or polyhydric alcohols and / or lanolin. It is advisable that the agent also contains dyes. It is advantageous if the composition further comprises pyrogallol and / or pyrogallol derivatives. It is desirable that the agent also contains sodium benzoate.

It is suitable to prepare the composition by first mixing the soaps with the solvents, and after the solution is made, the water is introduced into the solution of the soaps and hydrocarbon solvents or as a water emulsion in part of the hydrocarbon solvents. The water can be introduced into the solution of soaps and hydrocarbon solvents in the form of a liquid or in the form of water vapor.

The water can be introduced first into the soaps or a mixture of metal soaps of Group II of the periodic table of fatty acids and then mixed with hydrocarbon solvents until a solution is formed.

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Water can be introduced first into a hydrocarbon solvent or a mixture of hydrocarbon solvents, and then this two-component system - water with a hydrocarbon solvent can be introduced into soaps or into a mixture of soaps of Group II of the periodic table of elements and fatty acids.

The agent according to the invention has an apparent viscosity of from 200 mPa.s to 80,000 mPa.s. at shear rates from 30 s ^-1 to 1 s ^-1. The center is a plastically thixotropic liquid with a flow limit (critical shear stress) of 0.1 Pa to 15 Pa, which can be determined as required.

The graph in Figure 1 shows the dependence of the viscosity on the shear rate. In the proportional coordinate system on the abscissa the speed D ws ^{1 was set} , while on the ordinate the viscosity η in mPa.s. The curve a shows the viscosity versus shear rate dependence of an agent according to the invention. The agent is a 40% solution of calcium fatty acid soaps (from fatty acid still bottoms) in a hydrocarbon solvent with an aniline number of 65 with the addition of 2.8% water. The inventive viscosity of Example 1 is about 5.5 times higher than that of the agent known from RP Patent No. 74121. The straight b shows the dependence of the viscosity on the shear rate (for example for the agent known from RP Patent No. 130,516). Viscosity ("resting" 1 of this known agent is about 13 times not lower than the viscosity of the agent according to the invention. The apparent viscosity of the agent according to the invention decreases with increasing shear rate and for D = 15 s_ it is about 10 times lower than the viscosity " For higher D values, the apparent viscosity tends tangentially to a value close to that of the known agent.

The line b in Fig. 1 shows that the apparent viscosity of the agent practically known from RP No. 130,516 does not change depending on the shear rate. The viscosity of the known agent is equally low at rest and in flow, therefore the known agent drips after application.

After thickening of the known agent with a thixotropic mineral additive, the dependence of the (apparent) viscosity on the shear rate is arranged approximately along a curve similar to a from the diagram in Fig. 1.

The plot of Figure 2 shows the flow curve for an agent according to the invention in a logarithmic system. The flow curve is the dependence of the shear stress on the shear rate D. The shear stress τ in Pa is placed on the abscissa axis, while the

Λ ordinates shear rate D in sec. The agent according to the invention is a 60% solution of magnesium fatty acid soaps (from fatty acid still bottoms) in a hydrocarbon solvent with an aniline number of 55 with the addition of 2% water. The flow limit To is approximately 15 Pa. Such a high yield point means that the center will never drip even from a perfectly vertical plane down to a coating thickness of 1.2 mm.

The agent according to the invention is shown in an embodiment. Component amounts are given in parts by weight.

Example 1.40 parts by weight of a second saponification number 180 animal fatty acid still residue was saponified at 120 ° C with 4 parts by weight of caustic magnesite, calcined for 4 hours, and 60 parts by weight of a hydrocarbon fraction boiling at 100/140 ° C, density 0.75 aniline number were added. 55 ° C. Then 5 parts by weight of water were introduced into the reactor and the product was cooled. The obtained agent has the following composition:

- magnesium soaps of fatty acids from the distillation residue II of animal fatty acids with a saponification number of 180 - about 44 kg

- mixture of hydrocarbons with an aniline number of 55 ° C, density 0.75 kg / dm ³ and a fraction boiling in the temperature range of 100 ° C - 140 ° C - 60 kg

- water - 5 kg

The agent has an apparent viscosity of 10,000 MPa.s at a shear rate D of ls, and an apparent viscosity of 1000 mPa.s at a shear rate of 16 sec, and can be easily sprayed with airless sprayer without bleeding. The agent coating does not drip when applied with airless spray equipment and has good protective properties after drying. The protective properties were found on the basis of testing in a humidity chamber for 500 hours.

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Example II. 30 parts by weight of refined technical fatty acids and 10 parts of oxidized paraffin wax FP-25 with LK 35 were dissolved in a stirred reactor at 140 ° C and saponified by adding 5 parts by weight of hydrated lime and 1 part of zinc oxide over 6 hours, finally introducing heating with steam for 20 minutes. The reaction product was then diluted with 60 parts by weight of lacquer gasoline with an aniline number of 60 ° C. The obtained agent has the following composition:

a mixture of calcium and zinc soaps in a weight ratio of approximately 5: 1, respectively, derived from the saponification of refined technical fatty acids and an oxidized paraffin wax PP-35 with an acid number of 35 in a weight ratio of acids to wax of approximately 3: 1, in total approximately 460 kg;

- gasoline for varnishes with an aniline number of 60 ° C - 600 kg;

- water - 35 kg

The obtained agent has an apparent viscosity of 3500 mPa.s at a shear rate of 4s " ¹ and 500 mPa.s at a shear rate of 100 s", suitable for application with an air gun with a nozzle diameter of 1 mm. The agent coating showed no dripping when applied and after application by a pneumatic gun to painted bodies.

Example III. 40 parts of fatty acids from tall oil were saponified at 130 ° C with a suspension of zinc oxide in water in the amount of 4 parts of zinc oxide and 4 parts of water until the water was completely evaporated and diluted after 5 hours of reaction with 50 parts by weight of crude oil 150-200 ° C by aniline number of 80 ° C containing 1% water. Then, 1 part by weight of lanolin, fatty blue and sodium benzoate are added each. The obtained agent has the following composition:

- zinc soaps of fatty acids derived from tall oil, about -440 kg

- crude oil fraction with an aniline number of 80 ° C, boiling in the range of 150 ° C-200 ° C -500 kg;

- water - 5 kg

- lanolin - 10 kg;

- fatty blue - 10 kg;

- sodium benzoate - 10 kg.

The agent has an apparent viscosity of 40,000 MPa.s at a shear rate of 1 s and 2000 mPa.s at a shear rate of 500 s1, suitable for brush application without streaks.

The agent coating applied with a brush to the machine tool bed and the lead screw did not show any dripping and was easily spread without a scratch on the brush. After 24 hours of drying, the coating was hard and resistant to brine.

Example IV. A product with the following composition was developed:

- magnesium soaps of refined animal fatty acids - 400 kg;

- paraffin gas - 20 kg;

- petrol for varnishes C low-aromatic - 565 kg;

- distillate water - 10 kg;

- ester of oleic acid and sorbitol - 1 kg;

- sodium benzoate - 1 kg;

- silver aluminum dust - 2 kg.

Agent has an apparent viscosity of 1,200 mPa.s at a shear rate 2s_ lekość apparent and 2000 mPa.s at 100 s ^_ \ useful for the airless spraying without sagging of the coating.

Example 5 A product was developed with the following composition:

- magnesium soaps with II still bottoms of vegetable fatty acids LK 100-350 kg;

- a gasoline hydrocarbon solvent with a boiling point of 80-100 ° C and an aniline number of 75 ° C - 600 kg;

- water in the form of a heated water pore - 20 kg;

- paraffin micro wax LK 0.5 - 20 kg;

- pyrocatechin fraction - 10 kg.

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The agent has an apparent viscosity of 15000 mPa.s at a shear rate of 1 s " ¹ and iOOOmPa.s at a speed of 10 s" and is suitable for spray maintenance of steel structures.

Comparative tests of the agent according to the invention and the agents known from the Polish patent specification No. 74121 were carried out. The agent according to the invention prepared according to examples 2 and 3 and the agent known according to the example from the patent description No. 74,121 were subjected to the curve and yield stress tests. 3.

The diagram of FIG. 3 shows the flow curves for the agent of the invention according to example II - curve 2 according to example III - curve 3 and for comparison, for the agent known according to the example of RP No. 74121 - curve 1. Graphs 2 and 3 are as follows: for plastic liquids (according to Brigham), while curve 3 - in a manner similar to that for visoplastic liquids (according to Casson-Asbeck). For a known agent, the flow limit r ₀ is several times lower than the flow limit for the agent according to the invention. This means that when the agent according to the invention does not drip from the vertical wall to a thickness of 1.2 mm, the known agent does not drip down to a thickness of 0.35 mm, while at greater thicknesses it sags.

The rheological characteristics of the agent known from the example in RP No. 74121 and the agent according to the invention according to example IV were also investigated.

The table shows the rheological characteristics of the agent known from Polish Patent Specification No. 74121, by way of example and for comparison, the characteristics of the agent of the invention prepared according to Example IV.

Table

The agent is known Agent according to the invention Shear speed D (s' ¹ ) Viscosity η (mPas) Shear speed D (s ") Viscosity η (mPa.s) 1 35700 1 17800 1.8 28120 1.8 13140 3.0 23797 3.0 7932 5.4 18700 5.3 6056 9.0 14874 9.0 4627 16.0 11011 16.0 3300 27.0 8154 27.0 2924 49.0 5755 49.0 2424 81.0 4290 81.0 2192 146 3112 146 1390 243 2620 243 710 o. o η °° = 2500 mPas o. o 1? °° = 700mPas

At the shear rate D equal to 1 s " ¹ , the apparent viscosities are close to the" resting "viscosities. The viscosity of the asphalt undercarriage is much higher, and the apparent viscosities at certain shear stresses are on average 3 times lower for the agent according to the invention.

Claims (7)

Patent claims 1. An agent for the protection of metals against corrosion or for the protection of lacquer coatings against the action of destructive environmental factors, prepared on the basis of a mixture of metal soaps of the II group of the periodic table of fatty acids with hydrocarbon solvents, characterized in that it is a soap solution in the amount of 10 to 80 parts by weight and hydrocarbon solvents with an aniline number of 50 to 85 ° C in an amount of 20 to 90 parts by weight with water in an amount of 0.8 to 15 parts by weight. 153 462 2. The agent according to claim The method of claim 1, characterized in that it contains calcium and / or magnesium and / or zinc soaps of fatty acids in waxes resulting from the oxidation of paraffin and / or fatty acids contained in the distillation residue of fatty acids and / or its saponification products and / or acids polyanolin fatty acids and / or waste fatty acids from the processing of plant or animal raw materials and / or technical fatty acids from the processing of plant and / or animal raw materials. 3. The agent according to claim The process of claim 1, wherein the solution contains hydrocarbon solvents boiling at temperatures from 80 ° C to 250 ° C. 4. The agent according to claim 1 The process of claim 1, further comprising fatty acid esters and / or polyhydric alcohols and / or lanolin. 5. The agent according to claim 1 The process of claim 1, further comprising dyes. 6. The agent according to p. The process of claim 1, further comprising pyrogallol and / or pyrogallol derivatives. 7. The agent according to p. The process of claim 1, further comprising sodium benzoate. Fig 3 Department of Publishing of the UP RP. Circulation 100 copies Price: PLN 3,000