EP3461931A1 - Compositions of vapour phase corrosion inhibitors and their use and method for preparing them - Google Patents

Abstract

The invention relates to evaporation-inhibiting or sublimable corrosion-inhibiting substance combinations which contain at least
(5) a substituted 1,4-benzoquinone,
(6) an aromatic or alicyclic substituted carbamate,
(7) a polysubstituted phenol and
(8) a monosubstituted pyrimidine.

Preferably, these contain corrosion inhibiting substance combinations
1 to 30 mass% component (1), 5 to 40 mass% component (2),
2 to 20% by mass of component (3) and 0.5 to 10% by mass of component (4),
in each case based on the total amount of the substance combination.

The components may be mixed together or dispersed in water or else premixed in a solubilizer which is miscible with mineral oils and synthetic oils, preferably an arylalkyl ether alcohol, e.g. Phenoxyethanol.

Such combinations of substances may be used as vapor phase corrosion inhibitors in packaging or in closed space for the protection of common working metals such as iron, chromium, nickel, aluminum, copper and their alloys as well as galvanized steels against atmospheric corrosion.

Description

Background of the invention

The present invention relates to combinations of substances as vapor-phase corrosion inhibitors (vapor phase inhibitors VpCl, volatile corrosion inhibitors, VCI) and methods of their application for the protection of conventional utility metals, such as iron, chromium, nickel, aluminum, copper and their Alloys and galvanized steels against corrosion in humid air climates.

For several decades, compounds identified as corrosion inhibitors, which moreover tend to evaporate or sublimate even under normal conditions and can thus reach the metal surfaces to be protected via the gas phase, are used for the temporary corrosion protection of metal objects within closed spaces, e.g. used in packaging, control cabinets or showcases. Protecting metal parts from corrosion during storage and transport is the clean alternative to temporary corrosion protection with oils, greases or waxes.

All measures of the temporary corrosion protection of metals against the action of air-saturated aqueous media or condensed water films are known to preserve the primary oxide layer (primary oxide layer, POL) which is always present on the working metals after initial contact with the atmosphere from chemical and mechanical degradation (cf. eg: E. Kunze (Ed.), Corrosion and Corrosion Protection, Vol. 3, Wiley-VCH, Berlin, New York 2001, pp. 1679-1756 ). However, in order to cope with the corrosion inhibitors acting through the use of preferably vapor phase, it must be taken into account that the usual use metals and the POLs present on their surfaces have different chemical properties. Therefore, vapor phase corrosion inhibitors are basically of the type of metal to be protected select (see eg: US 4,374,174 . US 6,464,899 . US 6,752,934 B2 . US 7,824,482 B2 and US 8,906,267 B2 ).

Consequently, it is also necessary to use combinations of different corrosion inhibitors for articles and constructions which have been produced from different metals and, if appropriate, still in different processing states (rough, polished, polished, etc.), for the respective metals and surface states within one and the same container or a common packaging to ensure a reliable temporary corrosion protection. Since such mischmetal articles and components are technically most commonly represented by the present experience, finding suitable combinations of vapor phase corrosion inhibitors is still of increasing importance.

The use of such combinations of volatile corrosion inhibitors (VpCI / VCI) in practice should be possible above all after the already established applications, but adapted to the different sensitivity of the metals to be protected and surface states in air of different rel. Humidity and composition and compatibility of the individual components with each other.

In order to achieve reliable corrosion protection for metallic components within containers and packaging whose walls are permeable to water vapor-containing air (paper, plastic film, etc.), by means of VpCl / VCl, it is necessary to ensure that the active ingredients are sufficiently rapidly removed from the respective Depot are released by evaporation and / or sublimation, pass through diffusion and convection within the closed packaging to the metal surfaces to be protected and form a Adsorptionsfilm there before even at the same place water can condense from humid air.

The time referred to as the so-called conditioning or incubation time, during which the conditions for the VCl corrosion protection set after the container / the packaging has been sealed, may be more susceptible to corrosion Of course, metal surfaces should not be too large, since otherwise the corrosion process is already started before the VCI molecules have come close to the metal surface.

Depending on the nature of the metals to be protected and the surface states present, it is therefore not only necessary to use a suitable combination of VpCl / VCI components, but also to apply them in such a way that the so-called build-up phase necessary for the development of their effect is adapted to the respective requirements.

Even under normal conditions for sublimation prone solids make their vaporization equilibrium with the gas phase known, the easier the greater their specific surface area. To present such corrosion inhibitors in powder form with the smallest possible particle size, can therefore be considered as a prerequisite for setting a shortest possible building phase. VpCl / VCI in the form of finely dispersed powders, packaged in bags of a material which is permeable to the vaporous active substances (eg paper bag, porous polymer film, perforated capsule), have therefore long been commercially available. To expose them within a closed package next to the metal parts to be protected is the simplest form of practical application of VpCI / VCI (see eg: E. Vuorinen, E. Kalman, W. Focke, Introduction to vapor phase corrosion inhibitors in metal packaging, Surface Eng. 29 (2004) 281 pp ., US 4,973,448 . US 5,393,457 . US 6,752,934 B2 . US 8,906,267 B2 . US 9,435,037 and EP 1 219 727 A2 ). The build-up phases that can be achieved thereby can also be regulated by the permeability of the walls of such depots. If, instead of individual corrosion inhibitors, mixtures of different substances are used, then it must additionally be ensured that they do not chemically react with one another or lead to the formation of agglomerates, since this prevents both their emission from the depot and their required chemisorption on the metal surfaces to be protected or at least more impaired.

In modern packaging for temporary corrosion protection, VpCI / VCI are usually already integrated so that their technical application can be simple and automated. Papers, cardboards, foams or textile nonwoven material with a VCl-containing coating are just as familiar as polymeric carrier materials into which the relevant VCI active ingredients have been incorporated in such a way that their emission from them remains possible. So z. B. in the patents US 3,836,077 . US 3,967,926 . US 4,124,549 . US 4,290,912 . US 5,209,869 . US 5,332,525 . US 5,393,457 . US 6,752,934 B2 . US 7,824,482 . US 8,906,267 B2 . JP 4,124,549 . EP 0,639,657 and EP 1,219,727 various variants are proposed, always with the aim of introducing the VpCI / VCI in a depot, such as in capsules, coatings or gas-permeable plastic films in each case so as to result in a product from which the VCI components can evaporate or sublime continuously. However, to achieve this with combinations of several substances and set with respect to migration in depot and emission of a physically similar behavior for each component is, of course, complicated and obviously explains that in many applications with the previously known substance combinations especially for mischmetal objects and Components rarely optimal VCI corrosion protection properties can be realized. Thus, in individual cases, different particle sizes of the components of a substance combination may cause deficiencies in corrosion protection, for example if the structural pores of the walls of the drug depot are not large enough to ensure similar conditions for permeation and sublimation of the individual molecules or molecular associates for all components of the active ingredient mixture.

With the incorporation of VpCl / VCI into a coating composition, experience has shown that it is relatively easy today to produce coatings on sheet-like packaging materials (papers, cardboards, foams, textile nonwoven material, etc.) from which the respective VpCl / VCI are released at emission rates suitable for the VCI corrosion protection guarantee comparatively short construction phases. In the first instance, it requires the selection of a suitable coating agent which absorbs the substance combination introduced in powder form finely and with sufficiently high degree of filling on the respective substrate to form a well-adhering, porous layer, from which then the relevant VpCl / VCI can sublimate with little resistance , With the application quantity of VpCI / VCI coating agent, it is also possible to adapt the VpCI / VCI depot to the requirements of the shortest possible set-up phases.

Produce VpCI / VCI-containing packaging material by dispersing the active ingredients in a suitable coating agent and applied to a flat carrier material therefore, has been practiced for a long time. Methods of this type with various active ingredients and coating compositions are, for example, in JP 61,227,188 . JP 62,063,686 . JP 63,028,888 . JP 63,183,182 . JP 63,210,285 . US 5,958,115 . US 8,906,267 B2 and US 9,518,328 B1 described.

The incorporation of VpCl / VCI in polymeric carrier materials, preferably in polyolefins (PO), such as polyethylene (PE) and polypropylene (PP), and the provision of VpCl / VCI emitting films and other PO products (granules, trays, etc.), as they are z. B. is proposed in US 4,124,549 . US 4,290,912 , US 5,139,700, US Pat. No. 6,464,899 B1 . US 6,752,934 B2 . US 6,787,065 B1 . US 7,824,482 . EP 1 218 567 A1 and EP 1641960 B1 , Experience has shown that is practiced to a particularly high degree, if only because these products can be applied advantageously for the automation of packaging processes.

However, these polymer-based VpCl / VCI products generally have the disadvantage that the VpCl / VCI incorporated in the course of the extrusion via the polymer melt are relatively firmly enclosed within the polymer matrix in powder form or in coatings, in contrast to the VpCl / VCI depots described above and their emission is only comparatively difficult. In VpCI / VCI films, which are usually used today with layer thicknesses d in the range of 60 .mu.m.ltoreq.d.ltoreq.150 .mu.m, it is also possible to accommodate by far not so high specific active ingredient concentrations as, for example, in VpCl / VCI coatings. In addition, during the extrusion of the masterbatches and films concerned, losses of VpCl / VCI components that are difficult to control usually occur as a result of the thermal load that occurs. Experience has shown, therefore, that none of the VpCI / VCI substance combinations known hitherto has been able to provide films which are suitable for the VCI corrosion protection of metal surfaces susceptible to corrosion, if only because of the above reasons it was not possible to adjust the required relatively short construction phases. The commercially available VpCI / VCI films are therefore so far primarily as technologically easy-to-apply mass products in use, without being able to meet higher demands on their VCI anti-corrosion properties.

To improve this situation and to better profile packages of polymer films in terms of the incorporated VpCI / VCI system, several proposals have become known. As obvious, all measures appear to allow the emission of the integrated in polymer films VpCI / VCI components only in one direction, oriented to the metal part to be protected in the packaging, and to equip the other side as a barrier.

For this purpose, eg in US 5,393,457 A1 . US 7,763,213 B2 and US 8,881,904 B2 proposed that with a VpCI / VCI-containing film around the metal part to be protected primarily produced packaging with an additional barrier film to wrap. In the US 5,137,700 on the other hand, it is envisaged to laminate the outside of the VpCI / VCI film before use as a packaging material with a metal or plastic layer acting as a barrier and to specify the film provided with the VpCl / VCI components as the inside when packaging the metal part to be protected. The proposal according to US 8,881,904 B2 , the VpCI / VCI film from the outset by coextrusion multilayer produce and dosing into the layer positioned as the outside no VpCI / VCI masterbatch, according to personal experience does not mean that this outer layer of the film thereafter as a barrier to the permeation of vaporous VpCl / VCI components. Instead, usually the emission of VpCl / VCl components from the inner layer deteriorates in the gas space of the package, because the degradation of the required concentration gradient by migration of the active ingredients in the first drug-free outer layer already during storage of the coextruded film on the roll begins and a reduction VCI effect.

Since hitherto it was not possible to accelerate the emission of the relevant VpCl / VCI components into the interior of the closed packaging with the application of an additional barrier film or the exterior of a VpCl / VCI-containing film as diffusion barrier, further measures were suggested. in order to shorten the so-called build-up phase for the respectively integrated VpCI / VCI system in a foil packaging so that improved VCI corrosion protection properties result. One way in this direction is, for example, the coating of the inside of a polymer film with a gel containing the VpCl / VCI components, fixed under a gas-permeable inner film Tyvek® 1059 (DuPont) (cf. US 7,763,213 B2 ), whereby it should also be possible to specify much higher proportions of VpCI / VCI components, as it succeeds by direct integration into a polyolefin film by extrusion.

Another approximately similar way consists in the entry of single or multiple VpCI / VCI components in a suitable adhesive in order to subsequently coat the inside of polymer films according to the requirements (cf., for example: EP 2 347 897 A1 . EP 2 730 696 A1 . EP 2 752 290 A1 and US 2015/0018461 A1 ). Indeed, if an adhesive is selected that is compatible with the incorporated VpCl / VCI components and cures as a porous layer, one actually achieves higher emission rates of these components than from films in which the VpCl / VCI components were integrated during extrusion.

Finally, there are also proposals to use a VpCI / VCI system as finely dispersed powder directly in the film used as packaging material (cf., for example: US 8,603,603 ), as highly filled compacts (so-called premix, cf. US 6,787,065 B1 ) to place in addition to the metal parts to be protected, or to introduce it in the form of small granules in a flat, porous foam, on the other side of a thin polyolefin film was laminated (see, eg: US 5,393,457 and US 9,435,037 B2 ), further possibilities within a foil outer packaging to present a low-resistance, subliming VpCl / VCI system with a relatively high proportion.

So far, however, all these proposals are too costly and materially, so that in practice in the design of efficient corrosion protection packaging experience has shown that recourse to the already mentioned, as classically designated application variants of VpCI / VCI systems.

As is well known, these include the VpCl / VCI-containing oils, and there is still a growing demand for those products which are suitable for the VCI corrosion protection of components composed of different metals and processing states. Such a VpCl / VCI-containing oil is known to not only the relevant metal substrate on which it was applied as a thin film, but also surface areas of the same component or adjacent metal objects, the Because of their geometry (eg holes, narrow notches folded sheet metal layers) could not be coated with an oil film, protect against corrosion. For this, as with any VpCI / VCI depot already mentioned, it is again necessary that the VpCl / VCI components now emitted from the oil as the carrier material should not be allowed to flow through the vapor phase within closed spaces (eg packaging, containers, cavities) reach the oil-covered surface areas of metal parts and form there a corrosion-protective adsorption film.

VpCl / VCI oils are for example in the patents US 919,778 . US 3,398,095 . US 3,785,975 . US 8,906,267 . US 1,224,500 and JP 07145490 A described. By emitting volatile corrosion inhibitors as well as protecting the non-oil covered areas of metal surfaces against corrosion by the gas phase, these VpCl / VCI oils are significantly different from preservative oils whose anticorrosive properties are enhanced by incorporation of non-volatile and therefore only direct-contact corrosion inhibitors were. Such corrosion protection oils are, for example, in the patents US 5,681,506 . US Pat. No. 7,014,694 B1 and WO 2016/022406 A1 described.

However, most of the previously known VpCI / VCI oils were only profiled for the VCI corrosion protection of ferrous materials. They usually contain higher proportions of one or more amines, so that their migration within the oil phase and its emission therefrom into the atmosphere of a closed package can result in a relatively high concentration gradient. Correspondingly short is then also necessary for the development of their VCI-effect build-up phase. In this case, the amine, which has reached the metal surface to be protected via the gas phase, in the water condensed there from humid air, ensures an alkaline surface pH value at which the POL of conventional iron materials is resistant (cf., for example, E. Kunze (ed. loc cit). However, experience has shown that these amine-based VpCl / VCI oils are not suitable for the VCI corrosion protection of non-ferrous metals (eg Al and Cu base materials) and galvanized steels since their POL degrades at these high surface pH values to form hydroxo complexes is used and subsequently corrosion.

Amines which already have a vapor or sublimation pressure under normal conditions to be used as VCI / VpCl have been practiced for many years and are described in numerous patents (see, for example: E. Vuorinen, et.al, loc.cit US 8,906,267 B2 ). Today, it is restricted to the cyclic amines dicyclohexylamine and cyclohexylamine (cf., for example: US 4,275,835 . US 5,393,457 . US 6,054,512 . US Pat. No. 6,464,899 B1 . US 9,435,037 and US 9,518,328 B1 ) as well as the various primary and tertiary alkanolamines, such as 2-aminoethanol and triethanolamine, or corresponding substitutes (cf., for example: E. Vuorinen, et.al, loc.cit US 6,752,934 B2 and US 8,906,267 B2 ).

In contrast, the preferred secondary amines previously preferred for use, such as diethanolamine, morpholine, piperidine, u.a.m. hardly technically applied, after it became known that these are nitrosiert already in air under normal conditions easily to carcinogenic N-Nitrosaminen.

Since the cyclic amines and amino alcohols are liquid under normal conditions, they must first be converted into the solid state by salt formation for the abovementioned applications (for example for powder-containing emitters or incorporation into polymeric support materials). The relevant amine carbonates, nitrites, nitrates, molybdate and carboxylates, the latter predominantly the amine benzoates and caprylates, are today among the most commonly used for the corrosion protection of iron materials VCI / VpCl (see, for example: EP 0 990 676 B1 . US 4,124,549 . US 5,137,700 . US 393,457 . US Pat. No. 6,464,899 A1 . US 8,603,603 B2 . US 9,435,037 . US 9,518,328 B2 and JP 2016-117920 A ).

Especially in the case of the amine carboxylates, both the amine component and the associated carboxylic acid are volatile and thereby both pass through the vapor phase to the metal surface to be protected. The resulting there in the presence of water vapor surface pH is then usually in the neutral range, whereby the corrosion protection effect against non-ferrous metals is usually favorably influenced. On the other hand, amines alone, as already pointed out, lead to higher, alkaline alkaline surface pH values, which lead to corrosion phenomena, especially with aluminum base materials and galvanized steels.

Since amines usually have higher vapor pressures compared with the associated carboxylic acids even under normal conditions, experience has shown that, especially with films in which amine carboxylates have been incorporated as VCI / VpCl, the preferred depletion of the amine components takes place with increasing time. However, this inevitably leads to the fact that mainly only the remaining carboxylic acids are then emitted from films of this type which are in use or deposited for a relatively long time. If, however, only carboxylic acids pass through the vapor phase to the metal surfaces to be protected, then in the presence of humid air small surface acidic pH values are established. This prevents adsorption of the carboxylate species on the POL of the metal surface to be protected and thus counteracts corrosion inhibition (cf., for example: NS Nhlapo, Thesis "TGA-FTIR study of vapors released by volatile corrosion inhibitor model systems", Fac. Chem. Engng., Univ. of Pretoria, SA, July 2013 ). In the case of ferrous materials, however, there is initially no formation of visible corrosion products because their POL is known to be converted into a thin iron carboxylate cover layer which is imperceptible without modern optical methods. However, since such thin salt-like conversion layers are porous, finally, exposure to wet air on the iron-based material present in the pores causes corrosion to form hydrogen with the formation of visible corrosion products, as is the case with Al-based materials and galvanized steels when exposed to acidic aqueous media is. Therefore, VCI / VpCl preparations with amine carboxylates are, at best, suitable for the relatively short-term corrosion protection of iron materials, but are not suitable for the protection of mixed metal components.

The same applies to the application of nitrites acting as passivators. With these salts of nitrous acid it can be achieved that the POL of iron materials is spontaneously reproduced if it has been destroyed by partial chemical dissolution or local mechanical abrasion (abrasion, erosion) (cf., for example: E. Vuorinen, et al. loc.cit and US 6,752,934 B2 ). Therefore, you can find application for quite some time as VCI / VpCI. In particular, the relatively volatile salt dicyclohexylammonium nitrite (DICHAN) has been used for more than 70 years as a VCI for the protection of iron materials (see, for example, Vuorinen et al, loc. Cit.). This DICHAN is mentioned until recently as part of VCl / VpCl compositions in numerous patents (eg: US 5,393,457 . US 6,054,512 . US 6,752,934 B2 . US 9,435,037 . JP 2016-117920 A and EP 0 990 676 B1 ), but always only for VCI corrosion protection of ferrous materials. All known formulations containing the DICHAN, in most cases supplemented by further components, such as anhydrous molybdate, carboxylates, benzotriazole or tolyltriazole (cf., for example: US 5,137,700 . US 5,393,457 and US 6,054,512 ), have hitherto proved unsuitable for the protection of mixed metal components with aluminum and copper materials as well as galvanized steels for various reasons.

In an effort to provide VpCI / VCI packaging materials that are applicable not only to the protection of ferrous materials, but also at least to galvanized steels and aluminum materials, various amine-free VpCl / VCI systems have been proposed in which a salt of nitrous acid ( Ammonium or Alkalinalitrit) is combined with other substances capable of sublimation, such as various saturated or unsaturated carboxylic acids or their alkali metal salts, a multiply substituted phenol and / or an aliphatic ester of a hydroxy-benzoic acid (cf., for example: US 4,290,912 . US Pat. No. 6,464,899 B1 . US 6,752,934 . US 6,787,065 B1 . EP 1 641 960 B1 and KR 1020160011874 A ).

Other proposals, however, prefer amine- and nitrite-free substance combinations, for example consisting of various saturated or unsaturated carboxylic acids or their alkali metal salts in combination with an aliphatic ester of a mono- or dihydroxy-benzoic acid, an aromatic amide and if necessary still complete with benzotriazole or tolyltriazole for the Protection of Cu materials (see eg: US 4,124,549 . US 4,374,174 . US 7,824,482 ).

With admixing of selected sublimation-capable water-insoluble, but steam-volatile, multiply substituted phenols (cf., for example: US 4,290,912 . US 6,752,934 . US 7,824,482 . EP 1 641 960 B1 ), bicyclic terpenes and aliphatically substituted naphthalenes (cf., for example: US 6,752,934 ) succeeded, although the emission of the contained in the combination of substances VpCI / VCI components already under normal conditions, especially in air higher rel. To improve moisture and bring it into the usual level for amines. The thereby for both iron and the usual Non-ferrous metals resulting VCI corrosion protection, however, requires comparatively highly filled drug depots, since in addition to the relevant VpCI / VCI components always higher proportions of acting as a carrier substances must be accommodated.

With the in the US 8,906,267 B2 proposed VpCI / VCI combination, consisting of an aminoalkyldiol with C ₃ to C ₅ , a monoalkylurea, a preferably multiply substituted pyrimidine and benzotriazole, could be achieved in several metals and surface states existing objects a good VCI corrosion protection, without an admixture of as carriers of acting substances.

In particular, in the incorporation of VpCl / VCI combinations into mineral or synthetic oils, inorganic and organic salts such as the alkali nitrites, nitrates and carboxylates are in any case unsuitable because they are not sufficiently soluble therein. Such VpCl / VCI oils have therefore been formulated in the past mainly by using amines as VCI components (cf., for example: US 919,778 . US 1,224,500 . US 3,398,095 . US 3,785,975 and JP 07145490 A ), sometimes supplemented by further volatile additives, such as C ₆ to C ₁₂ alkylcarboxylic acids and esters of unsaturated fatty acids (cf. US 3,398,095 ). In the JP 07145490 A on the other hand preparations with ethanolamine carboxylates, morpholine, cyclohexylamine and various sulfonates are claimed. However, all these formulations have in common that under normal conditions, ie at temperatures <60 ° C., only the amine components are emitted and become active as VpCl / VCI.

Such VpCl / VCI oils are therefore suitable exclusively for the VCI corrosion protection of iron-based materials. In the case of zinc and aluminum, they are known to cause, together with condensed water, usually too high an alkalization of the surfaces, as a result of which severe corrosion occurs with the formation of zincates or aluminates, before finally giving rise to the hydroxides and basic carbonates for which the term white rust is customary. On the other hand, copper materials frequently undergo corrosion under the action of amines to form Cu-amine complexes.

To counteract this deficiency, the in the US 8,906,267 B2 Proposed VpCl / VCI combination of an aminoalkyldiol with C ₃ to C ₅ , a monoalkylurea, a preferably multiply substituted pyrimidine and benzotriazole can be added via a solubilizer so in a mineral oil or synthetic oil that a VpCl / VCI oil is formed with which can be a good VCI corrosion protection for a wide range of common commodity metals. Meanwhile, it has proven to be disadvantageous that only relatively small proportions of the VpCl / VCI components can be added so that the very good VCI effect of fresh preparations decreases more and more during longer-term applications. The same could be observed when such VpCl / VCI oil was diluted with a common mineral oil.

In order to satisfy the demand for VpCl / VCI treated oils for coping with the temporary corrosion protection of ferrous and non-ferrous metals with constructive small cavities, novel VpCl / VCI systems are therefore required, the application of which in practice does not have the disadvantages described connected is. In particular, preparations which are not only of interest for a VpCl / VCI oil but also at least for VpCl / VCI donors (mixtures of pulverulent VpCl / VCI components in pouches, capsules, etc.) and coated VpCl / VCI packaging agents ( eg paper, cardboard, foam).

With combinations of such VpCI / VCI, which are fully compatible with each other, especially effective VCI corrosion protection packages identified by long service life could be produced for the mentioned applications, eg preserving packages of VpCI / VCI oil treated engine blocks in containers sealed with a lid, in which additionally VCI-emitting bags, capsules or VCI-coated paper or foam blanks were placed, even for long-term storage always for saturation of the gas space of the containers with the VpCI / VCI components as a prerequisite for the maintenance of VCI corrosion protection to care.

The object of the invention is to provide over the above-mentioned disadvantages of conventional volatile, acting on the vapor phase corrosion inhibitors improved evaporation or sublimation corrosion inhibiting substances and combinations of substances, both as a powder mixture, and incorporated into coatings and oils under the practically interesting climatic conditions within from technical packaging and analogous closed containers with sufficient speed from the corresponding depot, eg a VpCI / VCI components containing bag containing a VpCI / VCI components coating on a support such as paper, cardboard or foam, or a VpCI / VCI components containing oil or sublimate after adsorption and / or Condensation on the surface of located in this space metal parts there provide conditions under which the usual utility metals are reliably protected from atmospheric corrosion.

Surprisingly, these objects could be achieved according to the invention by providing the combination of substances according to claim 1. More specific aspects and preferred embodiments of the invention are the subject of the further claims.

1. (1) ein substituiertes 1,4-Benzochinon,
2. (2) ein aromatisch oder alicyclisch substituiertes Carbamat,
3. (3) ein mehrfach substituiertes Phenol und
4. (4) ein monosubstituiertes Pyrimidin.

The combination of substances according to the invention comprises at least the following components:

1. (1) a substituted 1,4-benzoquinone,
2. (2) an aromatic or alicyclic substituted carbamate,
3. (3) a polysubstituted phenol and
4. (4) a monosubstituted pyrimidine.

The proportions of the various components may vary according to the particular field of application, and suitable compositions may readily be ascertained by one skilled in the art by routine experimentation.

In a preferred embodiment of the invention, the corrosion-inhibiting substance combination comprises 1 to 30% by weight of component (1), 5 to 40% by weight of component (2), 2 to 20% by weight of component (3) and 0.5 to 10% by weight -% component (4), in each case based on the total amount of the combination of substances contained.

The substituted 1,4-benzoquinone is preferably selected from the group consisting of tetramethyl-1,4-benzoquinone (duroquinone), trimethyl-1,4-benzoquinone, 2,6-dimethoxy-1,4-benzoquinone (DMBQ), 2,5-dimethoxy-1,4-benzoquinone, 2-methoxy-6-methyl-1,4-benzoquinone, and similarly structured, especially alkyl or alkoxy substituted, substituted 1,4-benzoquinones and combinations thereof.

The aromatic or alicyclic substituted carbamate is preferably selected from the group comprising benzyl carbamate, phenyl carbamate, cyclohexyl carbamate, p-tolyl carbamate and similarly structured substituted carbamates and combinations thereof.

The polysubstituted phenol is preferably selected from the group consisting of 5-methyl-2- (1-methylethyl) phenol (thymol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol) , 2-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, 2,6-dimethoxyphenol (syringol) and similarly structured polysubstituted phenols and combinations thereof.

The monosubstituted pyrimidine is preferably selected from the group consisting of 2-aminopyrimidine, 4-aminopyrimidine, 2-methylpyrimidine, 4-methylpyrimidine, 5-methoxypyrimidine, 5-ethoxypyrimidine, 4-phenylpyrimidine, 2-phenoxypyrimidine, 4- (N, N- Dimethylamino) pyrimidine and similarly structured monosubstituted pyrimidines and combinations thereof.

In the case of the corrosion-inhibiting substance combination according to the invention, the components (1) to (4) can be mixed together, for example, or dispersed in water or premixed in a solubilizer which is miscible with mineral oils and synthetic oils.

This solubilizer is preferably an arylalkyl ether alcohol customary for oil preparations, for example phenoxyethanol (Protectol PE), in which the components are present in dissolved or dispersed form.

In addition to the components (1) to (4) according to the invention and optionally the solubilizer, the corrosion-inhibiting substance combinations according to the invention may additionally contain substances already introduced as vapor-phase corrosion inhibitors, individually or as a mixture thereof.

The composition of the corrosion-inhibiting substance combinations according to the invention is preferably adjusted so that in the temperature range up to +80 ° C at rel. Humidity (RH) ≤ 98% evaporate or sublime all components with sufficient volume and speed for steam room corrosion protection.

According to the invention, these combinations of substances are used directly in the form of appropriate mixtures or incorporated according to methods known per se in the production of VpCl / VCI packaging materials and oil preparations, so that these packaging materials or oils act as a VCI depot and the anti-corrosion properties of the inventive substance combinations particularly can be advantageous to unfold.

In one embodiment, the corrosion-inhibiting substance combinations are used as a volatile corrosion inhibitor (VPCI, VCI) in the form of finely powdered mixtures or pellets (pellets) produced therefrom in the packaging, storage or transport of metallic materials.

However, the corrosion-inhibiting substance combinations can also be incorporated into coating materials or coating solutions, preferably in an aqueous / organic medium, and / or colloidal composite materials, in order to support materials such as paper, cardboard, foams, textile fabrics, textile non-wovens and similar fabrics within the scope of production to coat VCI-emitting packaging and then apply it during packaging, storage and transport operations.

In another embodiment, the corrosion inhibiting fabric combinations are used to make VCI anticorrosion oil from which vapor phase corrosion inhibitors (VPCI, VCI) are emitted.

Preferably, such a VCI anticorrosion oil comprises a mineral oil or synthetic oil and 0.5 to 5% by mass, more preferably 0.8 to 3% by mass, based on the oil phase, of a corrosion inhibiting substance combination according to the invention, optionally in a solubilizer, and the composition is adjusted so that from the VCI oil in the temperature range up to 80 ° C at rel. Humidity (RH) ≤ 98% evaporate or sublime all corrosion inhibitor components with sufficient volume and speed for steam room corrosion protection.

The combinations of substances according to the invention are used above all to protect the wide range of common working metals, in particular iron, chromium, nickel, aluminum, copper and their alloys and galvanized steels, in packaging and during storage in analogous closed spaces from atmospheric corrosion.

The substance combinations according to the invention are nitrite- and amine-free and advantageously consist exclusively of substances which can be easily and safely processed by methods known per se and in the applicable proportions are classified as non-toxic and the environment is not hazardous. They are therefore particularly suitable for the production of corrosion-protective packaging materials that are applicable on a large scale cost and without significant hazard potential.

For the introduction of the substance combinations according to the invention in VpCI / VCI depots or in packaging materials and oils acting as such, it is generally expedient to mix the individual substances in the anhydrous state as intensively as possible with one another according to methods known per se.

The substance combinations according to the invention are preferably formulated within the following proportions by weight: Component (1): 1 to 30% Component (2): 5 to 40% Component (3): 2 to 20% Component (4): 0.5 to 10%.

The subject of the application is explained in more detail by the following examples. As can be seen from this, the type, proportion of the individual components in the mixture according to the invention and the proportion of mixture in the respective VpCI / VCI depot only depend on the conditions of production of the relevant VpCl / VCI emitting product and the necessary processing aids, but not on the type of from corrosion to metal to be protected.

Example 1:

The following preparation according to the invention VCI (1) was prepared using the anhydrous components of the combination of substances according to the invention and further anhydrous substances serving as processing aids: 10.0 mass% Tetramethyl-1,4-benzoquinone (Duroquinone) 8.0% by mass benzyl 6.0% by mass 5-methyl-2- (1-methylethyl) phenol (thymol), 6.0% by mass 5-Ethoxy, 20.0 mass% Silica gel (SiO ₂ ) 10.0 mass% Sodium benzoate, (micronized, d ₉₅ ≤ 10 μm) 8.0% by mass 1-H benzotriazole 1.0% by mass 2- (2H-Benzotriazol-2-yl) -p-cresol (Tinuvin P, CIBA) 30.0 mass% non-polar PE wax (CWF 201, ALROKO) 1.0% by mass Calcium stearate (d ₉₅ ≤ 8 μm)

0.5 g each of this carefully homogenized powder mixture was filled into a prefabricated small pouch of Tyvek 1057 D (54 g / m ² ), a vapor-permeable plastic film, sealed its opening and then this bag on a perforated bottom insert made of PMMA , to the base of the to accommodate the 15 mm ensures a distance of approx. 15 mm. Under this soil, previously 15 ml of deionized water had been dosed. In addition to the filled Tyvek bag, a strip of PMMA with 5 mm deep notches was placed on the bottom insert. In each case 4 pieces of carefully cleaned test plates (90 x 50 xd) mm of different types were positioned vertically with a 15 ° inclination to the horizontal at a distance of 10 mm from each other. Each jar was 1 test plate made of DC 03 steel, cold-rolled, low-carbon, material no. 1.0347, d = 0.5 mm, aluminum 99.5, d = 0.625 mm (both Q-Panel Cleveland), Cu-ETP (MKM Mansfelder copper and brass GmbH), d = 0.5 mm and hot-dip galvanized steel DX56D + Z140MBO (Fine grain zinc coating 140g / m ² - 70/70 g / m ² - 10 μm, ArcelorMittal), d = 0.8 mm.

The mason jars with the test plates, the deionized water and the combination of substances according to the invention were sealed, for which purpose a cover with a sealing ring and three clamping clamps were used. After 16 h of waiting at room temperature, the so-called build-up phase of the VCI components within the vessel could be considered as complete. The individual mason jars were then exposed for 16 h in a heating cabinet according to DIN 50011-12 at 40 ° C, then again for 8 h at room temperature. This cyclic load (1 cycle = 24 h) was briefly interrupted after every 7 cycles, the mason jars were opened for approx. 2 minutes in order to replace the possibly converted atmospheric oxygen and to inspect the surface condition of the sheets. After a total of 35 cycles, the exposure was stopped and each specimen outside the mason jars was visually assessed in detail.

In reference to the substance mixture VCI (1) according to the invention, 0.5 g portions of a commercially available VCI powder were tested in the same way. This reference VCI powder (R1) consisted of 28.8% by mass Dicyclohexylaminbenzoat 67.1 mass% cyclohexylamine 1.5% by mass 1-H benzotriazole 2.6% by mass Silica gel (SiO ₂ )

Result of the test:

The test panels of the 4 different metals, which were used together with the composition of the invention VCI (1), had in all 4 parallel batches after 35 cycles an unchanged appearance.

In the case of the approaches with the commercially available reference system R1, only the sheets from DC 03 were still free from corrosion after 35 cycles. The sheets of Al 99.5 were coated on both sides with a yellowish brown tarnish layer and individual white punctiform precipitates, the sheets of Cu-ETP each had dark spots starting from the top up to a black tarnish layer. The test plates made of galvanized steel were already marked after 7 cycles in the edge areas by first stain-shaped approaches of white rust in most approaches, which had been pronounced flat during the further test cycles.

The commercial reference system R1 is therefore suitable only for VCI corrosion protection of iron-based materials. By comparison, the VCI effect of the substance combination VCI (1) according to the invention compared to the usual use metals is shown to advantage in a very advantageous manner from the example described.

Example 2

By introducing anhydrous components of the combination of substances according to the invention and other materials required as processing aids into an aqueous polyacrylate dispersion (PLEXTOL BV 411, PolymerLatex), a coating composition VCI (2) of the following composition was prepared: 1.0% by mass 2,6-dimethoxy-1,4-benzoquinone (DMBQ) 1.0% by mass benzyl 1.5% by mass thymol 2.5% by mass 2-aminopyrimidine 55.0 mass% PLEXTOL BV 411 6.0% by mass methyl ethyl ketone 16.0% by mass deionized water 10.0 mass% Sodium benzoate, (micronized, d ₉₅ ≤ 10 μm) 6.0% by mass Polymer thickener (Rheovis VP 1231. BASF) 1.0% by mass Defoamer (AGITAN 260/265, MÜNZING Chem.) and thus paper webs (kraft paper 70 g / m ² ) coated with a wet application of 15 g / m ² . Immediately after drying of the VCI paper VCI (2) according to the invention thus prepared in air, it was tested for its anti-corrosive effect in comparison to a commercial corrosion protection paper serving as reference system (R2).

The commercially available reference system (R2) with a grammage of 66 g / m ² contained the following active substances after chemical analysis: 6.2 mass% Triethanolamincaprylat 3.4% by mass Monoethanolamincaprinat 1.4% by mass benzotriazole 6.7% by mass sodium benzoate

In comparison with the combination of substances according to the invention in preparation VCI (2), the total proportion of active substance components in the reference system (R2) was thus about three times higher.

For comparative testing, analogously to Example 1, test plates made of steel DC 03, cold-rolled, low-carbon, material no. 1.0347, d = 0.5 mm, aluminum 99.5, d = 0.625 mm (both Q-Panel Cleveland), Cu-ETP (MKM Mansfelder copper and brass GmbH), d = 0.5 mm and hot-dip galvanized steel (fine grain Zinc coating 140g / m ² - 70/70 g / m ² -10 μm, ArcelorMittal), d = 0.8 mm for use. The test ritual again corresponded to that described in Example 1. The only difference was that, instead of the VCI powder mixture specified in a Tyvek bag, the individual mason jars were now lined with the VCI paper. This was done in each case with 1 circular cut with Ø 8 cm at the bottom, a coat of 13 x 28 cm and a again circular cut with Ø 9 cm for the lid, always with the coated side facing the insert with the to be protected against corrosion test sheets. After returning the 15 ml of deionized water was filled and the notched bar was placed with the 4 test panels on the bottom plate set, the mason jar was closed and the climate load, as described in Example 1, carried out.

At first, a waiting time of 16 h at room temperature was specified as the so-called build-up phase of the VCI components within the closed vessel. Thereafter, the exposure of the individual mason jars was again for 16 h in a heating cabinet according to DIN 50011-12 at 40 ° C, then for 8 h at room temperature. This cyclic load (1 cycle = 24 h) was briefly interrupted after every 7 cycles, the mason jars were opened for approx. 2 minutes in order to replace the possibly converted atmospheric oxygen and to inspect the surface condition of the sheets. After a total of 35 cycles, the exposure was stopped and each test sheet outside the mason jars was visually assessed in detail.

Result of the test:

The various test panels which were used together with the VCI paper VCI (2) prepared on the basis of the substance mixture according to the invention had an unchanged appearance after 35 cycles in all 4 parallel batches.

For the commercial reference R2 approaches, only the DC 03 test panels remained free of visible rust during the 35 cycles but were characterized by a duller appearance compared to the initial condition. The test plates made of Al 99.5 had dark, non-wipeable tarnish films on both sides in places.

At the edges of galvanized steel, after just a few cycles at the edges, first traces of white rust were observed, which increased significantly over the surface as the load continued. On the Cu-ETP test panels the appearance was uneven after 35 cycles. While the appearance of the sheet surfaces had remained unchanged in two runs, the other batches in the remaining batches had been covered in places with a thin, non-wipeable black tarnish film. This finding could not be excluded in the repetition of the tests.

Consequently, the reference system R2 is only suitable for VCI corrosion protection of iron base materials, while in the case of Cu base materials, the active substances emitted from the reference system R2 are adsorbed in such different specific concentrations that defects in the VCI corrosion protection effect result. In contrast, the VCI paper VCI (2) produced on the basis of the combination of substances according to the invention has, as the example shows, exhibited reliable VCI properties over the usual service metals even under the extreme moist air conditions with long-term stress.

Example 3:

By introducing anhydrous components of the combination of substances according to the invention and other materials required as processing aids into a commercially available mineral oil, a corrosion protection oil VCI (3) of the following composition was prepared: 0.6% by mass duroquinone 0.1% by mass benzyl 0.2% by mass thymol 0.2% by mass 4-phenylpyrimidine 92.7 mass% ( Mineral oil with thixotropic agent normal wax (BANTLEON base oil LV 16-050-2) 6.0% by mass phenoxyethanol 0.2% by mass Tolyltriazole (TTA, COFERMIN)

After intensive stirring, the VCI oil VCI (3) according to the invention resulted as an optically clear fluid, characterized by an average kinematic viscosity of 25 ± 3 mm ² / s (20 ° C).

In reference to the VCI oil VCI (3) according to the invention, a commercially available VCI oil of approximately the same mean kinetic viscosity was tested in an analogous manner. This reference VCI oil R3, which was also formulated on the basis of a mineral oil, contained the active substances after chemical analysis: 11.3 g / kg dicyclohexylamine 8.2 g / kg Diethylamino-ethanol 15.1 g / kg 3.5.5 trimethylhexanoic acid 3.6 g / kg Benzoic acid.

For comparative testing, analogously to Example 1, test plates made of steel DC 03, cold-rolled, low-carbon, material no. 1.0347, d = 0.5 mm, aluminum 99.5, d = 0.625 mm (both Q-Panel Cleveland), Cu-ETP (MKM Mansfelder copper and brass GmbH), d = 0.5 mm and hot-dip galvanized steel (fine grain Zinc coating 140g / m ² - 70/70 g / m ² -10 μm, ArcelorMittal), d = 0.8 mm, for use. The test ritual again corresponded to that described in Example 1.

The main difference was that the indented strips of PMMA used as test specimen racks were now each equipped with 3 pieces of one and the same test specimen, while the test specimen centered on both sides was covered with the VCI oil to be tested, each at a distance of 10 mm laterally arranged test plates were used without oil. It was thus possible to determine the extent to which the oil film applied to the centrally positioned test sheet is capable of producing both the metal substrate directly exposed to it and the emission of the VCI components via the vapor phase within the closed mason jar the two test panels not covered with an oil film To protect corrosion.

Each mason jar (volume 1 l) consequently now contained the notched PMMA strip on the perforated bottom insert and the 15 ml deionized water metered underneath with the relevant 3 test plates of one and the same material. After closing the individual mason jars, the climate load was carried out as described in Example 1.

At first, a waiting time of 16 h at room temperature was specified as the so-called build-up phase of the VCI components within the closed vessel. Thereafter, the exposure of the individual mason jars was again for 16 h in a heating cabinet according to DIN 50011-12 at 40 ° C, then for 8 h at room temperature. This cyclic load (1 cycle = 24 h) was briefly interrupted again after every 7 cycles, the mason jars were opened for approx Replace atmospheric oxygen and inspect the surface condition of the sheets. After a total of 35 cycles, the exposure was stopped and each test sheet outside the mason jars was visually assessed in detail.

Result of the test:

The various test panels, one of which was exposed to the VCI oil VCI (3) according to the invention coated with 2 similar, non-oiled test panels at a distance in a mason jar the cyclic humid climate, had in each case 3 parallel approaches after 35 cycles an unchanged appearance. The VCI oil VCI (3) according to the invention consequently ensured good corrosion protection both for the metal substrates in direct contact in question and for the test sheets inside the sealed mason jar with the VCI components not emitted by the oil.

In the batches with the commercially available reference system R3, the test plates made of the low alloyed steel DC 03 also exhibited no signs of corrosion after 35 cycles either in the oiled or in the non-oiled state. On the test plates made of Al 99.5, Cu-ETP and galvanized steel, on the other hand, this was only the case when oiled.

The test plates made of Al 99.5, which were presented in the non-oiled state, were coated with a brown start-up film after 35 cycles, which was mostly more intense at the edges of the sheets. On the non-oiled Cu-ETP test plates, dark gray to black-looking spots were observed after only 7 cycles at the upper edge regions, from which after 35 cycles in most cases relatively uniform, non-wipeable start-up films were formed.

The most noticeable changes were the changes in the non-oily used test plates made of fine-grain galvanized steel. Here, after 7 cycles of wet air application, selective approaches of white rust could be observed at the edge areas, from which larger, light gray to white-looking spots had formed with continuation of the moist air load.

Consequently, the reference system R3 can only be used in direct contact with the corrosion protection compared to the usual use metals. On the other hand, the active substances that are emitted into the gas phase are only suitable for VCI corrosion protection of iron-based materials. On the other hand, the VCI oil VCI (3) according to the invention, as the example shows, ensures a pronounced multimetal protection in that it develops reliable VCI properties in the long-term test, even under the extreme humid air conditions, in comparison with the usual utility metals.

Claims (15)

Evaporative or sublimable corrosion inhibiting substance combination containing at least: (1) a substituted 1,4-benzoquinone, (2) an aromatic or alicyclic substituted carbamate, (3) a polysubstituted phenol and (4) a monosubstituted pyrimidine. Corrosion-inhibiting substance combination according to claim 1, which contains 1 to 30% by mass of component (1), From 5 to 40% by weight of component (2), 2 to 20% by mass of component (3), and 0.5 to 10% by mass of component (4), in each case based on the total amount of the combination of substances. A corrosion inhibiting composition of matter according to claim 1 or 2, wherein the substituted 1,4-benzoquinone is selected from the group consisting of tetramethyl-1,4-benzoquinone (duroquinone), trimethyl-1,4-benzoquinone, 2,6-dimethoxy-1 , 4-benzoquinone (DMBQ), 2,5-dimethoxy-1,4-benzoquinone, 2-methoxy-6-methyl-1,4-benzoquinone, and similarly structured, especially alkyl- or alkoxy-substituted, substituted 1,4-benzoquinones and combinations thereof. The corrosion inhibiting composition of matter of any one of the preceding claims, wherein the aromatic or alicyclic substituted carbamate is selected from the group comprising benzyl carbamate, phenyl carbamate, cyclohexyl carbamate, p-tolyl carbamate and similarly structured substituted carbamates and combinations thereof. A corrosion-inhibiting composition of matter according to any one of the preceding claims, wherein the multi-substituted phenol is selected from the group consisting of 5-methyl-2- (1-methylethyl) phenol (thymol), 2,2'-methylene-bis (4) methyl-6-tert-butylphenol), 2-tert-butyl-4-methylphenol, 2.4.6-tri-tert-butylphenol, 2.6 dimethoxyphenol (syringol) and similarly structured polysubstituted phenols and combinations thereof. A corrosion inhibiting composition according to any one of the preceding claims wherein the monosubstituted pyrimidine is selected from the group consisting of 2-aminopyrimidine, 4-aminopyrimidine, 2-methylpyrimidine, 4-methylpyrimidine, 5-methoxypyrimidine, 5-ethoxypyrimidine, 4-phenylpyrimidine, 2- Phenoxypyrimidine, 4- (N, N-dimethylamino) pyrimidine and similarly structured monosubstituted pyrimidines and combinations thereof. Corrosion inhibiting substance combination according to one of the preceding claims, wherein the composition is adjusted so that in the temperature range up to +80 ° C at rel. Humidity (RH) ≤ 98% evaporate or sublime all components with sufficient volume and speed for steam room corrosion protection. Corrosion-inhibiting substance combination according to one of the preceding claims, which in addition to the components (1) to (4) according to the invention in addition also already introduced as vapor phase corrosion inhibitors substances individually or as a mixture thereof. VCI corrosion protection oil comprising a mineral oil or synthetic oil and a corrosion inhibiting combination of substances according to any one of claims 1-8, preferably in a proportion of 0.5 to 5% by mass, more preferably 0.8 to 3% by mass, optionally in a solubilizer , wherein in the temperature range up to +80 ° C at rel. Humidity (RH) ≤ 98% evaporate or sublime all components with sufficient volume and speed for steam room corrosion protection. A process for the preparation of a volatilizable or sublimable, corrosion inhibiting composition comprising at least (1) a substituted dichinone, (2) an aromatic or alicyclic substituted carbamate, (3) a polysubstituted phenol and (4) a monosubstituted pyrimidine. A method according to claim 10, wherein 1 to 30 mass% of component (1), 5 to 40 mass% of component (2), 2 to 20 mass% of component (3), and 0.5 to 10 mass% of component (4) are mixed together. Use of a corrosion-inhibiting substance combination according to one of Claims 1 to 8 as a volatile corrosion inhibitor (VpCl, VCI) in the form of finely powdered mixtures or pellets (pellets) produced therefrom in the packaging, storage or transport of metallic materials. Use of a corrosion-inhibiting substance combination according to one of Claims 1 to 8 for incorporation in coating materials or coating solutions in order to coat carrier materials such as paper, cardboard, foams, textile fabrics and similar fabrics. Use of a corrosion-inhibiting substance combination according to one of claims 1 to 8 for the production of a corrosion protection oil from which vapor-phase corrosion inhibitors (VpCl, VCI) are emitted. Use of a corrosion-inhibiting substance combination according to one of claims 1 to 8 or a VCI corrosion protection oil containing them for the corrosion protection of conventional utility metals, such as iron, chromium, nickel, aluminum, copper and their alloys, and galvanized steels, in particular within packaging, storage and transport processes ,