MXPA97002894A

MXPA97002894A - Corrosion resistant regulator or shock absorber system for metali products

Info

Publication number: MXPA97002894A
Application number: MXPA/A/1997/002894A
Authority: MX
Inventors: L Heimann Robert; M Dalton William; R Webb David
Original assignee: Elisha Technologies Co Llc
Priority date: 1994-10-21
Filing date: 1997-04-21
Publication date: 1998-10-23

Abstract

A system is described to inhibit the corrosion of ferrous and other metals by rendering metals passive. The system includes new cushioned compositions that can be applied to metal products to prevent or retard corrosion and methods for applying the cushioned compositions to metal products such that corrosion protection of the products is achieved through passivation. The methods include an in situ application to existing structures with metal reinforcements as well as applications to metal products during fabrication. In general, the compositions can be in various forms and comprise a carrier component and one more buffer components. The buffer or regulator is selected to preserve the proximity of the metal at a pH at which the metal is passive to corrosion. The compositions are environmentally friendly and are able to replace the chromates that have been traditionally used with zinc and zinc alloys to inhibit the corrosion of metals but without being potentially dangerous or harmful to the environment.

Description

CORROSION RESISTANT REGULATOR OR SHOCK ABSORBER SYSTEM FOR METALLIC PRODUCTS The present invention relates in a broad aspect to the inhibition of metal corrosion. The invention relates more particularly to compositions and methods for controlling the pH close to an initial corrosion point of a metal at a pH value where the metal is passive to corrosion. The invention relates more particularly to coating compositions comprising one or more materials in the form of particles or liquid materials, including one or more pH regulators or buffers. The compositions also preferably include one or more corrosion inhibitors, in particulate form or in liquid form. The compositions also typically include a carrier or other carrier for particulate materials and liquid materials, which preferentially take different forms, depending on the nature and form of the material being protected. The corrosion of steel and other metallic products continues to be a serious technical problem that has profound effects on the economy and the norm of REF: 24548 maintenance. It causes the premature replacement of the infrastructure, which in turn causes the loss of natural resources, and causes roads and buildings of inferior quality. Also, it causes the premature replacement of equipment and parts in the industry and in boats and other marine vehicles, automobiles, and airplanes. The corrosion process requires several physical conditions. These conditions include a metallic path, an electrolyte, anode, cathode, and a potential difference between the anode and the cathode (tendency to corrode). A metal path allows the transfer of electrons between the anode and cathode sites; Normally, the metal of the substrate is this route. Normally, the electrolyte is an aqueous solution around the substrate metal and contains ionic species capable of transferring charge between the anode and the cathode of the substrate metal. The anode is the location where the substrate metal corrodes and mass loss occurs. At the anode, the metal atoms lose electrons and become metal ions that creep up to the surrounding electrolyte. At the cathode, the ionic species receive electrons from the substrate metal and convert them back to the molecular form. The potential difference (or tendency to corrode) between the anode and the cathode can result from many different conditions including: variations in metallic or alloy compositions; difference in the amount of dissolved oxygen; presence of impurities in the substrate; resistance and / or ionic constituents; temperature differences; etc. Corrosion can be prevented, stopped or reduced by interrupting the transfer of electrons, by changing the chemistry at the anode or cathode, or by isolating the substrate from the electrolyte. Methods for achieving corrosion prevention include the use of barrier coatings or coatings, sacrificial coatings, corrosion inhibitors, cathode protection and passivation (stabilization) of the surface. Barrier coatings or coatings include paints, organic coatings, ceramic and inorganic coatings, plastics, noble metal deposits or coatings (such as nickel) and more. Sacrificial coatings prevent corrosion by having a great tendency to corrode from that of the metal they protect, thus converting the metal of the substrate to a nobler (non-corrosive) potential. Sacrificial coatings include zinc, aluminum and magnesium metals and alloys applied as coatings, coatings applied by hot dip, tanks, or as fillers in primers and paints or other organic coatings. The corrosion inhibitors change the chemistry of the surface at the interface between the metal substrate and the electrolyte solution. This barrier in the interface can be formed by oxidizing the surface of the anode, by precipitating a film or barrier layer which limits the diffusion of the ionic species between the bulk electrolyte and the surface of the substrate, or by absorbing compounds that impart a hydrophobic film to the surface of the metal substrate. Cathodic protection of a surface of a substrate can be achieved by converting the entire surface of the substrate metal to a cathode through the use of sacrificial anodes or applied electrical current. The passivation of the surface comprises the import of an oxide film to the metal surface of the substrate, thus preventing or reducing the tendency of the substrate metal to develop anode and cathode sites. Metallic substrates develop passive surfaces in specific environments or when exposed to solutions with specific pH ranges. For example, steel and iron substrates are naturally passive when exposed to aqueous solutions having a pH of 8.5 or lower. Also, aluminum has a naturally passive surface due to an oxide that forms a tightly adhering oxide film that limits the additional exposure of oxygen to the metal substrate. However, passive films can be attacked and compromised by certain ionic species. In the case of iron materials and iron alloys, the naturally passive surface can be compromised by chlorine ions and hydrogen ions, among others. The mechanisms of protection against corrosion, mentioned previously, have serious disadvantages. Barrier coatings can be expensive and offer very little protection against corrosion if they are compromised, mechanically damaged, or have insufficient coverage. Sacrificial coatings have the potential to create brittleness of high strength steels due to the creation of monatomic hydrogen by-products from the corrosion reaction. Also, the coatings can be used quickly under certain conditions of accelerated corrosion. Corrosion inhibitors are often expensive and it has been shown that some are environmentally unsafe or toxic. Many of these are only available as liquids, which makes them unsuitable for certain applications since they work best at certain concentration intervals. Cathodic protection can be a costly means of protection that requires experts to design and apply. It is more easily applicable to new structures, but it is difficult and / or expensive to install in an existing structure. Surface passivation has been used relatively little because it requires control of the environment around the surface of the substrate metal. In nature, there are stable materials in their lowest energy form. Iron typically exists as an iron oxide mineral. Humanity spends a tremendous amount of money refining and adding energy to iron ore to create steel and other iron products with the properties necessary for the manufacture of metal products and for the construction of roads, bridges, constructions, and the like. The natural response of these products to the environment is to return to its lowest, most stable state of energy, that is, the state of iron oxide. This corrosion process is accelerated when the products are exposed to corrosion constituents in the environment. Large amounts of time and money are spent annually on the use of coating materials to inhibit this corrosion. The eight types of corrosion are defined by the National Society of Corrosion Engineers, specifically: (1) General; (2) Located; (3) Galvanic; (4) Environmental cracking; (5) Cavitation and Wear by Erosion-Corrosion; (6) Intragranular; (7) Disbalance; and (8) High temperature. General corrosion results from open exposure to corrosive conditions. The localized condition affects smaller portions of the metal surface than general corrosion, but the penetration speed may be faster. Slit corrosion is a form of localized corrosion that results from corrosive exposure in a protected location where oxygen reduction occurs. The reduction of oxygen results in the development of acidic conditions that accelerate the corrosive loss of the base metal. Electromotive corrosion is an accelerated form of localized corrosion due to lost electrical currents that pass through an active corrosion cell.

General corrosion, crevice corrosion and electromotive corrosion are typically the kinds of corrosion of primary interest with iron and steel products. However, this invention is not only applicable in the inhibition of these kinds of corrosion, but also in the inhibition of other types of corrosion. Galvanic corrosion occurs when two metals with different potentials or tendency to corrode are in metal-to-metal contact. Corrosion with wear is the wear or damage that occurs in the interface of two surfaces that make contact, at least one of which is a metal, when subjected to rubbing, ie detachment in minutes relative to each other . Intragranular corrosion is a selective or localized attack on, or adjacent to, grain boundaries without appreciable attack on the grain. Corrosion by desalting is a phenomenon associated with the selective removal of one or more component of an alloy. Slit corrosion is a special form of corrosive action since it can typically comprise a bacterial or microbial attack accompanied by an environmental change in pH with anaerobic conditions. The microbes that produce corrosion of metals can be classified into five general groups: 1) acid producers that oxidize the sulfur compounds to change the sulfur compounds to sulfuric acid; 2) slime formers that help in the protection of anaerobic micro-environments; 3) sulfate reducers that consume hydrogen and depolarize cathode sites; 4) hydrogen feeders that are fueled by hydrocarbons; and 5) metal ion concentrators / oxidants that work in conjunction with other microbes to create thick, bulky deposits to create concentration cells. Typically, more than one type of microbe is working at any site of crevice corrosion in a symbiotic relationship, encouraging the growth of others. This form of attack is often hard to detect, since by definition, initiation is often in small crevices hidden in an anaerobic site. These sites frequently exhibit deep pitting, which compromises the structural integrity of the base metals under attack. The conditions that favor the promulgation of corrosive microbes include anaerobic environments, the pH in the range of 0.5-10 (depending on the type of microorganism), and high concentrations of hydrocarbons on which microbes feed. The metal cords used in concrete structures can be ideal initiation sites. The cords used in these structures are typically of a 1x7 high strength steel construction. Unfortunately, almost as soon as this concrete structure is placed, cracking begins to occur. These cracks allow water and other corrosive materials to penetrate the structure and thereby compromise the integrity of the structure. Cracks not only become ideal crevice corrosion sites, but also, they establish the potential physical degradation of a structure by alternating freeze and thaw cycles with the hydraulic force of the water that breaks from the concrete. The current cable market for post-tensioned and pre-tensioned, pre-stressed concrete is dominated by the 1x7 bare steel cord. The bead is available with an epoxy coating fused to the surface of the epoxy containing optional aluminum oxide grains to promote bonding with the concrete (ASTM Specification A882 / A882M). In addition, the 1x7 cord that contains grease and is covered with polyethylene is also available for specific applications. For bridge ties and tower supports, cable ducts made of plastic or steel materials such as galvanized or polyethylene steel, as containment for individual strands or multiple bundle of strands are typically used routinely. Cable ducts are commonly filled with grout to strengthen the assembly and to fill in the interstices. The alkaline nature of the grout becomes passive against corrosion to the steel surface. The cord and wire rope for the automotive industry and other general purpose uses typically typically have a coating of zinc or zinc alloy made by immersion in a hot bath and may be covered with a number of thermoplastic coatings. The zinc or zinc alloy coatings protect the surface of the steel against corrosion that will be galvanic due to its sacrificial nature (steel is preferentially corroded). Also, organic plastic materials have been used to fill the interstices between the wires in some cable products. Corrosion-resistant coatings, based on ceramic products, have been developed and are currently in use in rope cord products for the automotive parking brake. However, ceramic coatings are not usually suitable for wire rope products because the abrasiveness of these coatings reduces the fatigue life of the wire rope. The use of bare cord products causes problems when exposed to corrosive environments. The surface of the cord is not protected from the corrosive constituents in the environment. The stored cord that is to be placed in the casting beds (forms that are reused time to time to make or fabricate prefabricated concrete structural elements) frequently shows signs of initial red collapse before it encircles the protective enclosure. concrete. In the case of the cord used as a pre-tensioner for concrete materials, corrosion can occur when corrosive constituents such as salts thaw compounds, mix with concrete, or the marine environment migrates to the surface of the cord. Initially, the pH in the concrete is almost 12.0. Corrosivity increases as the pH of the concrete decreases or when carbonation occurs. Due to the chemical reactions incurred during the curing cycle of the concrete mixture, there are healing zones that streak and promote cracking of the surface of the healing mixture. Depending on the curing conditions, the types of mixtures and aggregates, and the surrounding physical conditions, this cracking may or may not be readily visible to the eye. The expansive forces caused by the development of corrosion in the steel cord or other steel reinforcement can also crack the concrete. Whatever the origin, the cracks can accelerate the degradation of the concrete and also the degradation of the pre-tension cord (when exposing the steel), needing repair or replacement of the concrete member to avoid the failure of the structure. The bare cord has no protection against corrosion except for the surrounding concrete. Frequently, rehabilitation projects use sealants in cracked concrete to decrease the opportunity for water or other corrosive elements to enter cracks and accelerate the degradation process. Typically, these sealants only provide a physical barrier and do not deal with the underlying steel components that are the subject of the corrosive attack.

The epoxy coated cord, the only current commercial alternative to bare cord for pre-tension applications, has a number of limitations. The epoxy coating effectively offers only barrier protection against corrosive constituents. When the barrier has been compromised due to imperfections in the coating or handling in the field, the corrosive constituents can reach the cord wires and cause local corrosion to develop. The corrosive constituents can then migrate below the epoxy coating, developing corrosion cells in crevices and causing delamination of the epoxy coating on the surface of the cord wires. Slit corrosion can cause a rapid failure of the cord wires as well as a reduction of the pH in the area of the corrosion cells. The epoxy coating has good overall chemical resistance, but it can be attacked by oxidizing materials such as chlorine, fluorine and hypochlorite materials. Sodium hypochlorite is commonly used as an additive in water treatment and bleaching in the pulp and paper industries. The hypochlorite ion can also be formed in alkaline environments (such as concrete) when chlorine or chloride ions are present. The construction of pre-fabricated members using epoxy-coated cords requires the use of special jaws in the cord during the tension process. Even with the special jaws, detachment sometimes occurs, causing the removal of the epoxy coating and adding difficulty to the construction of the pre-framed members. Jaws that are typically reused 60-70 times for the bare cord often require cleaning after only two or three uses with the epoxy-coated cord. It is common practice for post-tension cables that are to be enclosed with hydrocarbon grease and lined with a polymeric coating that draws oxygen. Cord and wire rope products filled with grease are typically limited to applications where high bond strength (post-tension applications) and bridges are not required. It has been shown that grease offers good protection against corrosion when it is present in excess; however, bare areas may occur due to rubbing. Fats can be expelled during periods of high temperatures, and many oils and fats become acidic over time, increasing the threat of corrosion. This acid condition accelerates the ion exchange between the surrounding electrolyte and the metal substrate. Slurry of cord tendons can lead to air pockets or gaps between the tendons where corrosive materials can be collected. Some blends commonly used in slurry formulations are corrosive to steel reinforcement. The interstices between the individual wires forming the cables or cords frequently show the first place of attack. An article in 1985 described the process of a bio-film community as follows: (1) metallic surfaces of infillation of iron oxidizing bacteria and "roots" seated to anchor a community; (2) slime and fungus formers are attracted to this site due to nutrient capacity and / or protection; (3) sulfate-reducing bacteria thrive in this anaerobic layer producing copious amounts of corrosive hydrogen sulfide gas; (4) Aerobic / anaerobic stratification is typically layered with the first layer of bio-film that protects an underlying anaerobic community.

Electromotive corrosion, as well as crevice corrosion, is also an accelerated form of corrosion that may be due to lost electrical currents from nearby cathodic protection systems or power cables, or static electric currents generated from frictional contact, as for example, between automotive tires and drive surfaces as well as friction by the gear and bearings (and subsequently being discharged through the parking brake, automotive cables). There are many different types of corrosive environments. Marine, Mold Areas, Water Treatment Means, Energy Plants, Pulp and Paper Mills and Chemical Process Plants. Natural corrosive products such as salts from marine environments, and man-made corrosive products such as acidic contaminants, corrode infrastructure and metallic products. Structures that require protection from corrosive constituents include roads, bridges, dykes, parking garages and docks. In this regard, people everywhere are increasing demands for roads, bridges and parking garages free of snow and ice by using de-icing salts. Unfortunately, these salts additionally contribute to the deterioration of the infrastructure. Metal products that require protection from corrosion constituents include metallic parts of boats and marine equipment, automobiles and airplanes. Considerable effort has been put into the construction and automotive industries, among others, to delay and reduce the corrosion rate of steel. This corrosion can result in the failure not only of the steel, but also of the elements and structures that support the steel. For example, corrosion of reinforcing steel members in concrete is known to result in concrete deterioration. This deterioration is believed to be due in large part to the fact that the corrosion products tend to occupy a larger volume of space than the original steel, resulting in stresses in the surrounding concrete material. Structural hazard may also occur due to a reduced cross-sectional area of the steel or a loss of bond between steel and concrete. In industrial applications, metallic corrosion can be accelerated by several factors such as the infiltration of oxygen and moisture ("general corrosion") and the presence of lost electrical currents ("electromotive corrosion"). Also, metallic corrosion can be accelerated by bacterial attack in highly acidic environments (ie, pH <; 2.0), anaerobes on the metal surface ("microbiologically induced corrosion"). A well-known method to prevent corrosion of steel is galvanization. In particular, zinc and zinc alloys are commonly used together with thermoplastic covers to coat the cords and wire rope in many industries. Zinc and its alloys are known to protect the steel surface in a sacrificial manner, since zinc preferentially corrodes the steel. However, a major disadvantage of this treatment is that the zinc coating provides only temporary protection of the base metal. Also, the coating may corrode unevenly, jeopardizing the integrity of the underlying metal. The zinc electroplating processes used to galvanize ferrous substrates frequently lead to the hydrogen brittleness of steel products, notably high strength steels, which are highly stressed. In addition, the corrosion of any galvanic zinc coating (zinc-filled coating, electrodeposition, mechanical plate, coating, thermal spray, immersion in a hot bath) can cause the hydrogen brittleness of high strength, highly stressed steel such as the reinforcement cord used in concrete and bridge ties. For the above reasons, many industries have begun to investigate alternative treatments against corrosion. For example, most of these treatments that have been developed for wire products comprise the coating or encapsulation of the base metal with various compounds such as plastics, ceramic products, epoxy resins, fats and other hydrocarbon-based substances. These substances can be applied either on the outside of the metallic cables or cords or in the interstices of the cables or cords. However, these treatments only provide a physical barrier to corrosive elements such as moisture and oxygen, and do not face the corrosion of the steel itself. Additionally, even with these applications, steel is still vulnerable to crevice corrosion, since highly acid, anaerobic environments will frequently appear on the metal surface, thus promoting bacterial attack. Current industry standards for corrosion prevention are centered around the use of heavy metals (chromium, nickel, lead, cadmium, copper, mercury, vario, etc.) or heavy metal compounds to render passive or provide a barrier to inhibit, or galvanically sacrifice, and thereby protect the substrate metal below. The introduction of these materials into the environment, however, can lead to serious health consequences as well as the substantial cost to contain or separate materials or clean up environmental pollution. Therefore, dealing with corrosion is a continuous problem and better systems are still needed to prevent corrosion. The present invention is related in a broad aspect to a system for inhibiting the corrosion of ferrous and other metals by rendering metals passive. The invention relates in a general aspect to compositions in various forms which are applied to a metal, and which involve a carrier component and one or more buffer or buffer components. The buffer or buffer may be in the form of particles or the liquid form but is otherwise soluble or ionizable in water, and is selected to retain the metal's proximity at a pH at which the metal is passive to corrosion. In general, the buffer is preferred in liquid form where a smoother or smoother coating is desired. The buffer or regulator in liquid form, such as buffer particles dissolved in aqueous solution, may solidify or dry after application to the metal, but must be kept ionizable and capable of being re-dissolved when contacted by aqueous corrosive materials. It is believed that the particles of the buffer of this invention that have been dissolved, are usually smaller in drying, than the buffer particles of this invention in the form of particles, and therefore allow a smoother appearance in the metal. In addition, it is believed that these absorber particles that have dissolved form a matrix or network in the drying. The absorber particles preferably vary in size in order to dissolve over extended periods of time and thus provide a continuous damping function. The carrier can take preferred forms such as films, gels, sealants, etc. depending on these factors such as the type, configuration and service of the metal. The carrier can also vary in its physical and chemical nature, again depending on several factors. In general, the carrier must be sufficiently viscous to support the damper or regulator in a uniform manner within the carrier. The compositions of the invention preferably include components capable of inhibiting the corrosion of any given metal in the presence of moisture or other sources of corrosion promoters. The inhibitor components co-act with the components of the buffer to provide protection against corrosion and can be specifically chosen to inhibit microbiological growth. From the foregoing, it becomes apparent that the invention provides an intelligent corrosion inhibition system that not only renders passive to a metal facing corrosion, but also maintains this protection for extended periods of time. The system does this by providing a cushioned environment by means of damping agents. Accordingly, corrosion protection is not limited to the use of reactive metals or barrier films traditionally employed in corrosion preventative coatings. In fact, an important nature of the invention resides in its environmentally friendly nature and provides "green" protection. The invention intentionally minimizes and preferentially avoids the use of heavy metal corrosion preventive means or other preventive means that can contaminate an application site or enter the surrounding environment. The intelligent nature of the systems of the invention is induced by a choice of carriers and layers as reflected by the product or apparatus to be protected against corrosion. In this way, as noted previously, the carrier can take the form of a gel, film, sealant, adhesive or other suitable medium. Additionally, one or more layers of the medium can be applied to a metal. In addition, one or more layers can be designed to be water repellent or to serve as barriers to corrosive materials such as air, carbon dioxide, chloride ions, etc. The present invention relates to (1) new cushioned compositions that can be applied to metal products to prevent or retard corrosion; (2) methods for applying the damped compositions to metallic products, for example metallic cables, such that the corrosion protection of the products is achieved through passivation; and (3) systems for in situ application to existing structures with metal reinforcements. The compositions of the invention thus reside in a preventive means against corrosion or rust which includes a carrier in which a buffer or regulator is dispersed which serves to maintain a pH for a metal in contact with the carrier that is in the range of values of pH where the metal has a natural passivity to corrosion. The carrier is in a form suitable for application to the metal for a long period or generally on a permanent basis. However, for gel application to the wire rope, the gel can be reapplied in the service as necessary. In this way, after application to a metal surface, the carrier is preferably selected to adhere to the metal surface as an adhesive or gel, or to be immobile or cured to remain on the surface. The buffer or regulator component may be in the form of particles that preferably vary in size from thin to thick in order to provide a buffer function that is both immediate and persistent. The particle sizes can thus typically vary from about 0.5 μm to 850 μm and preferably about 0.5 μm to 500 μm. The particle size distribution can vary from case to case, depending on the atmosphere or environment in which the corrosion preventive medium should be used. In general, it seems that a preferred distribution for many applications is 0.5 μm to 500 μm. However, for some wire rope applications the recommended particle size is less than 20 μm. Alternatively, the buffer component can be dissolved in solution, preferably an aqueous solution. After application to the metal, the dampening components may dry out or return to the solid form, but must be able to easily re-dissolve in the presence of corrosive liquid. The concentration of the buffer in any given carrier should preferably be the consistent maximum that facilitates handling and stability of the entire composition. The function of the dampers or regulators is well known since the buffer solutions act to minimize changes in the concentration of the hydrogen ion (pH) that would otherwise tend to occur as a result of chemical reactions. Once formulated, these solutions tend to resist the additional change due to outside influence. This makes it possible to adapt the response of the shock absorber to resist pH changes caused by changes in temperature, pressure, volume, redox potential or acidity, etc. Buffer or buffer solutions are typically prepared by mixing a weak acid and its salt and a weak base and its salt. Acid buffers, for example, can be prepared using potassium chloride or potassium acid phthalate with hydrochloric acid of appropriate concentrations. Neutral buffers can be prepared by mixing eg potassium dihydrogen phosphate and sodium hydroxide. Alkaline buffers can be prepared (basic) when mixing eg borax or disodium acid phosphate with sodium hydroxide. Many more chemical combinations are possible, using the appropriate chemicals to establish the proper sequence of the proton transfer steps coupled with the proposed reactions. The exchange rates of the shock absorber can be modified by combinations of damping materials that react at different ion exchange rates; Low-change type shock absorbers react more quickly than high-change types. As noted above, the buffer or buffer compositions of the invention serve to maintain the pH of the carrier in contact with a metal at a value at which the metal has a natural passivity to corrosion. In the case of iron, steel and other iron alloys such as stainless steel and Monel alloys, the pH at which these materials have a passivity to corrosion is in the range between about 8 and 13. In the case of aluminum and alloys of aluminum, the range is between about 5 and 7. In the case of bronzes, the range is more frequently between about 7 and 10. In general, most metals suitable for use with the present invention are naturally passive to corrosion at pH values above about 3.0. The materials that can serve as buffers in any given case can vary considerably, depending on the pH at which the near metal has a natural passivity to corrosion. Well-known buffers or regulators include alkali metal or tartrates, tetroxalates, phosphates, phthalates, borates, and the like, alkali metal acids, wherein the alkali metal is preferably sodium or potassium. Another commonly used buffer is calcium hydroxide. Preferred buffers include sodium and potassium silicate, and especially mixtures of these silicates. The buffer in any case must comprise dry particles in the anhydrous or hydrated form or dissolved in solution, preferably aqueous solution. In general, the hydrated form of any given buffer or regulator is preferred over the anhydrous because of its easier solubility in water. The invention in a broad aspect can be considered as a macro-infiltrated, micro-laminated system since high concentrations of a pH buffer are incorporated in a carrier or vehicle, and the carrier or vehicle charged with the buffer is preferably applied to a metallic product in a plurality of thin layers. When the particulate form of the buffer is used, as noted above, the buffer particles are preferably present in a range of particle sizes to become active as buffers for a prolonged period of time.

When applied as films or coatings, the rust preventive compositions of the invention are preferably applied in a macro-infiltrated, micro-laminated form. The lower layers typically comprise multiple thin layers of a carrier loaded with liquid buffers or buffers in the form of particles of variable particle size to impart a buffering action with time release, actively. The liquid shock absorbers preferably dry after application on the metal to be protected. One or more intermediate layers can serve as barrier layers for the underlying cushion layers. In this way, particles or potassium silicate liquid can be incorporated in one or more intermediate layers to prevent air and moisture from reaching the buffer layer or the metal. Potassium silicate reacts with carbon dioxide to form an insoluble film that protects the underlying buffer layers from premature dissolution. The layers of barriers, intermediates can be coated with one or more layers having water-repelling or sealing properties. A macro-infiltrated carrier with potassium silicate particles, for example, forms layers with strong hydrophobic qualities. The carrier in this case can be a polymeric material such as polyacrylic, silicone, polyurethane, epoxy, vinyl polymer or polyvinylacetate. The present invention has particular application in the protection of wire cables and metal cables that are made of multiple strands of wire. In this application, it is generally preferred that the compositions of the invention be in the form of a jelly-like, macro-infiltrated viscous carrier with one or more particle shaped buffers. The product preferably resembles a thixotropic gel which tends to become fluid under shear stress, but is established as a relatively firm structure. The thixotropic nature produces desirable physical properties to the composition. However, a thixotropic nature is not necessarily required. The gel can be applied to individual strands during the manufacture of a wire rope or wire rope, but it can also be injected into, and along, a wire rope and wire rope after fabrication. The thixotropic properties of the gel allow the cushion composition to flow along the interstices between and surrounding the cords forming the wire rope or wire rope. The thixotropic properties also allow the material to take a much more permanent position once injected into a wire rope or wire rope, thus providing long-term protection. As noted above, the wire rope and the wire rope are especially subject to crevice corrosion. The present invention for its gel formulations is especially effective in treating this corrosion. Formulations which include not only a buffer such as an alkali metal silicate but also a bactericide and / or fungicide, preferably a metal borate, such as a zinc borate, are particularly effective. This invention is also very effective in the protection and rehabilitation of existing infrastructures through the use of a thixotropic composition that can be pumped, which is applied in the existing cracks of a supporting concrete structure. The composition reacts to changes in the environment that are conducive to corrosion and releases cushions to change the pH of the site surrounding the bars or other metallic structures to be protected. When a tendency for the fall of the pH is found, the reactive components of the composition work to render the metal surface passive and actively limit any chloride ion. Once the is pumped. composition in a structure, its nature is activated, thixotropic and it becomes an agent of prevention for the physical entry of fluids. By raising the existing pH of the corrosion site, the corrosion that is taking place is combated and the changes are further reduced or eliminated. The present invention lies, in a broad aspect, in an intelligent corrosion inhibition system that renders passive the material to be protected and provides long-term protection by maintaining a cushioned environment via the solubility of the cushioning compounds such that it does not Corrosion will probably occur. Although the invention can be used to complement and reinforce the performance of sacrificial coatings and deposits, the system of the invention is not dependent on any of the reactive metals or barrier films traditionally found in corrosion preventative coatings. In fact, an important aspect of this invention lies in its environmentally friendly nature and provides "green" protection. The method or system of the invention for preventing corrosion can be easily implemented using gels, coatings, films, sealants, adhesives, and the like as carriers for the cushioning material. Suitable buffer or regulator materials are chosen such that, when in contact with moisture, the metal substrate is dissolved and buffered in the pH range imparting natural passivity to the substrate. A significant feature of the damping of the proximity of the substrate is that the damper will resist changes in pH continuously from the passive range of the substrate and will thus resist potential corrosion. A release characteristic can be obtained over time with a particle-shaped buffer where the particles are of a variable size. Similarly, a release characteristic can be obtained over time with a liquid buffer that dries after application. The small particles dissolve completely for short-term protection, while the larger particles require a larger time frame to completely dissolve and offer protection with a longer duration. The dissolution of the buffer and the migration of the carrier is controlled by the concentration gradient. This feature adds an intelligent feature to the coating system whereby if moisture in the vicinity of the substrate contains sufficient damping materials, the rate of dissolution and migration of the dampers from the carrier will decrease. As noted above, the compositions of the invention can be employed in various forms especially films, coatings, gels, sealants and adhesives. Each of these forms are discussed later.

Films and Coatings The technology of the regulators or dampers of the invention can be incorporated into films and other coatings to produce a macro-infiltrated, micro-laminated, shrewd coating system. This coating system provides protection against corrosion to the substrate metal via the release of buffer or regulator materials over time when the coating system is compromised by the damage and moisture is present. The coating system does not require, and preferably excludes, the use of environmentally undesirable heavy metals in the elemental or non-elemental form. The coating system includes one or more coating layers that are micro-infiltrated with buffer materials or buffers, in the form of particles, solids or liquid buffers. Buffer materials can be added to water-based resin systems and solvent-based resin systems as long as they are compatible. Aqueous polymers are preferred carriers for buffers in the liquid form and include water-reducible alkyls and modified alkyds, latexes, acrylics, acrylic-epoxy hybrids, water-reducible epoxies, polyurethane dispersions, vinyl and ethylene vinyl acetates. The cushioning materials are not generally affected by the curing methods and can be used in resin systems that cure via curing mechanisms with air drying, heat, chemical crosslinking, ultraviolet and others. These buffer materials can be added in the form of particles or dissolved in a solution, preferably an aqueous solution. The particulate buffers can be added in the coating systems in a range of particle sizes to achieve a release characteristic over time. The damping materials applied in the dissolved form will form a network or buffer matrix within the carrier and will also effect a release characteristic over time. When a coating has been damaged and brought into contact by moisture, the dampers begin to dissolve and migrate out of the coating to deaden the proximity of the metal substrate to be protected. The smaller cushion particles dissolve more quickly and offer rapid damping for a short duration. Larger particles require more time to fully dissolve, thus offering a longer duration of protection and release characteristic over time. The dissolution rates of the damping materials are dependent on the concentration gradient of the damping materials between the interior of the cladding and the area surrounding the cladding. In this way, when moisture first enters the vicinity of the coating, the dissolution and migration of the buffer materials occurs. As the concentration of the cushioning materials outside the coating increases, the rate of dissolution and migration of the coating cushions decreases. As the concentration of the buffer materials outside the coating decreases, the buffers are again filled by dissolution and migration from the coating. This characteristic of the cushioned coating provides a shrewd characteristic to the coating system. The damping materials are chosen based on the type of substrate to be protected. Metallic substrates can be protected from corrosion by rendering the surface of the substrate passive. This passivation can be achieved in general only in certain pH ranges, which in turn, depend on the specific substrate to be protected. For example, alloys based on iron become passive with an alkaline pH (pH 8-12). This pH range is preferably achieved with sodium silicate and / or potassium silicate powders, but other alkali metals can be used. Especially useful is a mixture of sodium silicate and potassium silicate for the achievement of speed control in water-based formulations. Potassium silicate powder materials can also be incorporated as an insolubilizer in a secondary stratification outside the primary stratification of the buffer. The materials react with carbon dioxide to form an insoluble film that protects the primary stratification of the buffer from premature dissolution. A tertiary, water-repellent, exterior, macro-infiltrated with aluminum silicate stratification can be used to impart hydrophobicity to the coating system. Aluminum silicate is largely insoluble in water. In a preferred embodiment of the present invention, films or layers are used that are cushioned with barrier layers that cover the cushioned layers, and also with water-repellent, exterior layers that cover the barrier layers. All layers are infiltrated with particles or with liquid to form a micro-laminated, macro-infiltrated coating system. The innermost layers comprise appropriately chosen damping materials to impart time-sensitive, shifty damping to achieve passivation of the surface of the substrate metal. An intermediate coating layer acts as a barrier to protect the buffer layers. A top layer comprises a polymeric film macro-infiltrated with an aluminum silicate or other materials to achieve hydrophobicity (water repellency). In addition, various pigments and corrosion inhibitors can be incorporated in these coatings. Where desired, these coatings may contain sacrificial metals or may be applied over base coatings containing elemental or non-elemental metals or conversion coatings, such as a zinc deposit with or without a chromate conversion coating. the corrosion already provided by the metals by traditional deposits of zinc or zinc alloys on metals, with or without chromates, receives a significant increase and reinforcement in the corrosion protection with the coatings of this invention, and particularly with these coatings comprising sodium silicate buffers. More significantly, the coatings of this invention can be applied to phosphate-treated surfaces, particularly zinc phosphate, iron phosphate and manganese phosphate, which can be effectively replaced by environmentally friendly chromates to provide "greener" protection "against corrosion. In this way, for these applications, the macro-infiltrated, micro-laminated system offers the possibility of eliminating toxic and environmentally unfriendly chromates without sacrificing protection against corrosion. Applications for the films and coatings of the invention include, for example, components for the automotive industry, home consumer products, construction and infrastructures, components of the aerospace industry, and other external or corrosive applications where the use of heavy metals in the elemental or non-elementary form is environmentally undesirable. Films and coatings can be applied to new products or on conventional tanks to extend the service life of the coated component with a metallic layer.

Gels These are suctions in which a dispersed phase of the buffering agent, preferably in the form of particles, is combined with a continuous phase to produce a viscous, jelly-like product. In the present invention, a synthetic oil is preferably used for the continuous phase. The shock absorber system is added to provide specific protection for the application. Gels exist at a location in the state between liquid and solid and can be adapted to act as either one or the other. Thixotropic gels allow an application in a state that approximates the liquid for ease of insertion into cracks and the sub-sequential return to solid nature to physically resist water intrusion. The cushioned gels of the invention form an excellent transport vehicle for attacking the corrosion sites that have developed within a surrounding concrete envelope. The gels and their chemical products can reach deep into the structure and are then located to passively return to a metallic (steel) surface. Any of the chloride ions introduced into the concrete can be chemically bound by the reactive components of the gel, and in this way the deterioration of the structure and reinforcing steel is stopped. Thixotropic gels that use synthetic oils as a continuous or carrier phase have proven to be effective in the practice of the invention. Examples of synthetic oils include oils based on synthesized hydrocarbon fluids, alkyl benzenes, dibasic acid esters, polyol esters, polyglycols, olefin oligomers, polybutenes, cycloaliphatics, silicones, silicate esters, polyphenyl ethers, and fluids. halogenated These fluids can be adapted to have a controlled molecular structure that exhibits the best properties of a petroleum-based system (mineral oil) as well as properties not found in hydrocarbon greases. Petroleum hydrocarbon fats fail at temperatures approaching 176 ° C (350 ° F), while some synthetics maintain excellent properties up to 426 ° C (800 ° F). The gels formed with the above synthetic fluids can be filled with many different buffers, preferably buffers in the form of particles and special components such as barrier materials and corrosion inhibitors. The attractive gels have been filled with sodium silicate, potassium silicate, and zinc borate in amounts of approximately 10 volume percent, each amounting to approximately 30 volume percent. A particularly applicable synthetic gel is based on a synthetic polyolefin (alpha decene) fluid available under the trademark NY0GELR from William F. Nye Inc. Specific formulations have included 10 volume percent each of sodium silicate, silicate potassium and zinc borate. Silver borate can be added in environments with high concentrations of chloride ions. Applications for the gels of this invention include: 1. Metallic cable used in aircraft, marine, mining, automotive, oil field, and transportation applications, both as a lubricant and for protection against corrosion; 2. Cord used in construction such as pre-stressed cables and post-tensioned cables in concrete, and bridge ties typically found in tiered bridges, parking garages, ground anchors, concrete constructions, railway sleepers, aqueduct concrete pipes, and containers for water containment and chemical products; 3. Gels injected into cracks in concrete for rehabilitation purposes; 4. Discharge gates for containers or water / chemical containers; 5. Anti-seizing compounds; 6. Balloon valves / gate valves in corrosive environments; and 7. Cables for suspended bridges.

Gels can be applied to metal cables, wire and cord cords during manufacturing or in the field, before or after metal cables, wire or cord cables are placed for use.

Sealers In this form, the particulate agents are dispersed in an organic or synthetic substance that is formulated to be soft enough to be poured or extruded, but is also capable of subsequent hardening to form a permanent, flexible bond with the metal substrate.

Typically, the sealants are synthetic polymers such as silicones, urethanes, acrylics, polychloroprenes, or the like, which are semi-soluble prior to application and subsequently become elastomeric. A few of the best known sealers are side products such as linseed oil, mastic, asphalt and various waxes. In addition, a suitable damper or regulator system of the invention acts to protect the mechanical structures from corrosion. Applications for the sealants of the invention include: 1. Home and industrial caulking used to cope with weather or water, which seals the needs typically created by overlapping joints of similar or different materials; 2. Construction of ships, automobiles and airplanes, which are additional examples of industries that create a myriad of overlapping metal joints that result in potential sites of crevice corrosion; and 3. Foamable sealants used in automotive and aircraft applications to fill gaps, provide seals against water and dampen sound.

Adhesives In this form, the dampers of the invention can be dispersed in organic, inorganic and synthetic polymers that provide chemical and / or physical bonds between the metal substrates for a strong bond, as opposed to the sealants that remain flexible. Other suitable adhesive type carriers include rubber-based and latex-based materials, as well as hot melts formulated from polyethylene, polyvinyl acetate, polyamides, hydrocarbon resins, and also natural asphalts, bitumens, resinous materials and waxes. These adhesive materials formulated with the appropriate damping systems of the invention provide protection to the substrate from general corrosion, different metal corrosion, and crevice corrosion. Applications for the adhesives of the invention include any of the overlapping metal joints designated for bonding by adhesive for re-assembly or repair. Table A gives examples of suitable buffering components that can be used in accordance with the present invention, while Table B gives examples of suitable weight ratios of these buffering components for different pH values. Of course, other weak acid / conjugate base or weak base / conjugate acid systems may be used, provided that they are compatible with the base carrier matrix.

Table A - Examples of Shock Absorbing Compounds Table B - Examples of Weight Ratios of Shock Absorbing Components for Various pH Values Table B (continued) Table B (continued) For example, a buffer system comprising a weight ratio of 1.00 :: 30.40 sodium hydroxide to potassium diacid phosphate would be suitable to protect aluminum and aluminum alloys from corrosion, in accordance with the present invention. Using the above table for shock absorbing systems applied in a liquid phase, the appropriate, indicated weight of the buffer is dissolved in water. This invention finds particular application in the manufacture of wire rope to provide resistance against corrosion to the wire rope. The invention can also be applied after cable fabrication and even after the cable or metal structure has been installed to provide corrosion resistance to the cable, or to delay or stop the corrosion of the cable. An environment is created that surrounds the substrate that is not conductive to the initialization of corrosion. As used herein, the terms "wire" or "wire rope" and "wire product" shall be understood to include wire ropes and wire ropes having multiple wire ropes or filaments. The term "wire" should be understood to include a metal rod or rod, such as a thread or cord. A "wire" or "wire rope" as used herein may be comprised of an individual wire or multiple wires. Cables for use in pre-stressed and post-tensioned concrete typically have a central wire, sometimes called a "king" wire, usually with six wires wrapped around it (although additional layers or covers may be added depending on any particular application ). It should be noted, however, that this invention is not limited to cables of this form or for this use. In general, the present invention can be applied to any metal surface where protection against corrosion is desired. In one embodiment of this invention, a gel is formulated which contains buffers in an amount sufficient to allow the gel to buffer the pH in a range in which the metal to be protected against corrosion is naturally passive to corrosion . To protect the steel, iron or iron alloy, a gel comprising a polyalphaolefin (1-decene) base and about 10% by volume of sodium silicate, approximately 10% by volume of potassium silicate and about 10% by volume of zinc borate. This composition, when applied to the surface of steel, iron or iron alloy, provides a damping of pH for the metal in the pH range between 8-13.

The base component of the gel can be selected from alkylated aromatics, phosphate esters, perfluoroalkyl polyesters, olefins, chlorotrifluoroethylene, silahydrocarbons, phosphazenes, dialkyl carbonates, oligomers, polybutenes, and polyphenyl esters, as well as unsaturated polyglycols, silicones, silicate esters, cycloaliphatic hydrocarbons, and dibasic acid esters. To protect or render passive to steel, iron or iron alloys, a polyalphaolefin base oil having a kinematic viscosity in the range of about 30-1,400 centistokes at 40 ° C has been found especially effective. Other properties to consider when choosing a suitable polyalphaolefin base oil are molecular weight, molecular branching, thermal stability and hydrophobicity, depending on the application. The polyalphaolefin base oil is thickened to a gel with thickeners known in the art of fat manufacturers such as polytetrafluoroethylene or silica. Also, the cushioning materials are suitable as thickeners so long as they are compatible with the base oil. In general, synthetic, low molecular weight hydrocarbon oils provide greater ease in the design and manufacture of a gel with particular desired characteristics but are more expensive than less refined, high molecular weight petroleum hydrocarbon oils. The less refined hydrocarbons can also have the disadvantage of containing sulfur compounds that can feed the sulfate-reducing bacteria and in turn, tend to corrode metals such as steel, iron and iron alloys. In another embodiment, of this invention, a polymer film or adhesive containing buffers is formulated in an amount sufficient to allow the film or adhesive to buffer the pH in the pH range in which the metal to be protected against corrosion is naturally passive to corrosion. The polymer can be a thermoplastic, thermosetting, or crosslinked system. Examples of these systems include epoxies, acrylics, polyurethanes, silicones, polyesters, alkyds, vinyls, phenolics, fluoropolymers and latexes. To protect the steel, iron or iron alloy, a polymer-based film or adhesive comprising about 10% by volume of sodium silicate, about 10% by volume of potassium, and about 10% by volume has proved very effective. in zinc borate. The films and adhesives of the invention are preferably applied while the polymer carrier or base is in a low viscosity range to help ensure the complete coating of the metal to be protected against corrosion. The viscosity of the polymer base is preferably between about 100 and 15,000 centipoise (25 ° C), depending on the application. Brushed surfaces (for example) require a more viscous base than one that will be coated by a more fluid spray, bath or rotation with a bath. Subsequently, the film / adhesive can be cured by suitable methods known in the art (generally exposure to air) to produce a protective, buffer system around the base metal. In yet another application of the invention, buffer or regulator materials are added to friction materials such as those used in the manufacture of brakes. Typical examples of these friction materials are thermosetting, phenolic resins containing iron powder and / or steel fibers or other metal fibers for reinforcement. These damping materials can be added as particles to the dry mixture of the iron powder and / or steel or metal fibers. Preferably, these damping materials are applied to the iron powder and the steel or metal fibers by themselves, for example by a dry spray technique such as by spraying or spraying atomized or vaporized sodium silicate solutions or other material Damper in the powder and fibers and then condense it to a film in the powder and fibers before the formulation of the dry mix. For example, a Glatt spray dryer can be used to achieve this technique. In this application of the invention, damping materials such as sodium silicate are preferably added to the metal to be protected against corrosion in two coatings, with the inner coating adjacent to the metal remaining soluble to maintain its damping capacity and the outer coating on this inner coating which is applied at a higher temperature capable of fusing the outer coating in a barrier layer, insoluble or more preferably a metal chloride, eg zinc chloride, is applied to the powder and fibers coated with the buffer, again, for example by a spray or dry spray technique, such that a film or metal chloride coating, partially insoluble, covers or encloses the powder and the fibers coated with the buffer. The solubility of the resulting materials decreases with the increase in the amount of metal chloride applied to the powder and fibers coated with buffer and thus with the increase in the thickness of the metal chloride coating. In yet another application of the invention, damping materials are added to damping or regulating materials in the form of particles, for example by a spray or dry spray technique. That is, a vaporized sodium silicate or other sodium silicate damping material can be sprayed or sprayed into the sodium silicate in the form of particles or another buffer. Then a metal chloride, preferably zinc chloride, is again applied, for example by a dry spray technique, to the buffer particles covered with a buffer. The metal chloride provides a partially insoluble coating to the coated particle. For example, zinc chloride applied over a sodium silicate buffer results in a zinc silicate film that covers the buffer particles covered with buffer. The less metal chloride is applied, the greater the degree of insolubility of the coating. These coated buffer particles can be added to dry blends of friction materials as an alternative to, or in addition to, the damping coating of the same friction materials as discussed above. In this use, the coated buffer particles provide control against corrosion for example, when the friction materials are included in brake pads. Other materials may be added to the compositions of the present invention to further adapt them to their desired applications. For example, additives such as ceramic silicates (for example zircon) or silicas (for example smoked silica, silicon dioxide, amorphous silica) can be used to control viscosity and improve thermal resistance. Polymers such as polyethylene powder, nylon, Teflon or tetrafluoroethylene fluorocarbon and polyester can be added to provide extreme pressure tolerance properties for improved fatigue performance. Pigments can be added to provide color. These additives must be selected to be compatible with the main purpose of the invention, which is to serve as a pH buffer. Also, materials can be added to improve the damping or corrosion resistance of any given metal. For example, silver nitrate can be added to react with possible chlorides to form precipitates with limited solubility, thereby helping to prevent chlorides from being available to corrode steel, iron or iron alloys. Preferably, the compositions and methods of this invention will not employ heavy metals such as zinc, chromium, nickel, lead, cadmium, copper or lithium, especially in the pure form. Zinc borate is generally acceptable because it has very limited solubility. The interest is greater for pure metals or soluble cations. The invention by nature does not release components except where necessary, such as hydroxyl ions to buffer the pH, and in this way can be generally considered to be environmentally safe or friendly, or to provide "green" protection. In the application of the invention, once a composition of the invention has been formulated with the ability to act as a buffer for a desired pH range, the pH range at which the metal has a natural passivity to corrosion, the composition is placed next to the metal to be protected. For example, the gel, adhesive, and film compositions of the invention can be applied to the wire rope during manufacture. In this application, the damped carrier is preferably applied in a complete manner to at least the central or "king" wire as well as the interstices that immediately surround the "king" wire. The film or adhesive compositions can be cured to provide a permanent, protective damping region around the treated wires. Whether or not the compositions have been applied to the wires used to make a cable, they can be applied after the cable has been manufactured or installed. In this manner, the compositions of the invention can be pumped through holes or cracks in the reinforced concrete to reach and protect the bars, reinforcement cables, underlays, or the like. Thixotropic gel compositions are especially attractive for this service.

In certain applications, the compositions of the invention, once they have been applied, can be given in an outer coating in the form of a thermoplastic, paint or the like, for example, bridge ties that are constantly exposed to marine environments adverse The thermoplastic or other polymeric outer covers on the straps help protect the straps after they have been coated with a composition of the invention. When the composition is a gel type that is to be used in cable applications where bonding with concrete is desired, or when the outer coating is to be applied, the composition should be restricted to covering the inner wires of a cable for help prevent adhesion problems that comprise the composition and the concrete or the polymeric cladding. The use of an outer polymeric envelope is not always defended in the case of the cable used in pre-stressed or pre-stressed concrete, because the cable must be generally joined to the concrete; an outer envelope could most likely interfere with this joint. An advantage of the invention is that its effectiveness does not depend on, nor does it need, an outer covering or cover.

The compositions of the invention can also be applied to various metal assemblies. For example, the adhesives of the present invention can be applied to overlapping joints, where two metal sheets overlap and are joined by welding, riveting, metal folding or the like. The cushioned adhesives are applied to protect the metal joints from corrosion. The gel and adhesive compositions of the invention have a particular application to nut / bolt assemblies to prevent corrosion-induced seizure. In these applications, the gel is preferably applied to the threads of the nut or bolt both before and after the units are connected. Tests have shown that metals coated with gel, film and adhesive compositions of this invention show substantial resistance to corrosion. Even after corrosion has begun, applications of the compositions according to the invention have resulted in a significant arrest or delay of further corrosion. In this way, this invention has application not only in the manufacture of metallic products, but also in the prevention and on-site rehabilion of metallic products. To further illustrate the present invention, but not by way of limion, the following examples are provided: EXAMPLE 1 The following materials were used: - bar samples No. 5 of bare steel of 30.48 cm (12 inches) long (ASTM-A615), available from Chapparal Steel Co.; - Synthetic Polyalphaolefin Hydrocarbon Gel Lubricant (NYOGEL 747GR) from William F. Nye, Inc .; - Powdered potassium silicate (KASIL SSR) from PQ Corp .; - Sodium silicate GDR, available from PQ Corp .; - Zinc borate in the form of particles (BOROGARD ZBR), available from U.S. Bórax Co.

First, approximately 50 ml of each of the powders of potassium silicate, sodium silicate and zinc borate were mixed together for about 15 minutes to provide a homogenous, buffered composition.

A 24 ml sample of a dry powder mixture was then slowly added to a 40 ml sample of the polyalphaolefin material NY0GELR to produce a gel with 60% damping agents by volume to achieve a buffering range of 10-9 pH. 12 Three sets of bar samples were prepared for the test. In all samples, the oxide layer of the surface and the corrosion initially present in the bar were left unchanged. The first set was designated as the control group, consequently, no treatment was applied to these bar samples. The second set was prepared by brushing at approximately 0.50 grams / inches of NYOGEL 747GR pure gel at 5 inches from the midpoint of the bar samples, while the third set was prepared by brushing at approximately 0.68 grams / inch of the damped NYOGELR mixture at 5 inches from the midpoint of the bar samples. The samples were then exposed to a 5% saline solution in a constant temperature environment for 1632 hours, in accordance with ASTM B117-73. The degree of corrosion in the test parts was determined by visual inspection at time intervals of 24-72 hours.

Table C The NYOGEL 747GR pure gel bars have red corrosion spots below the gel at 24 hours and were completely covered with red rust at 96 hours. On the other hand, the bars with buffered gel, after they show initial signs of corrosion under the gel at 96 hours, kept the total level of corrosion of each bar below 40% throughout the experiment. Therefore, it is evident that the cushioned gel material is capable of retarding both the onset and progression of corrosion on metal surfaces, compared to pure gel compounds.

Example 2 The following materials were used: - M12X40 bare steel bolts and nuts from Bossard CL08 (DIN 933 &934); - Hexagonal head bolts of 0.82 cm x 6.35 cm (5/16 inches X 2.5 inches) steel length with a zinc plate with NF threads and corresponding nuts from Westlakes Hardware; - Synthetic, synthetic polyalphaolefin hydrocarbon gel lubricant, AM940126 from William F. Nye, Inc.; - Powdered potassium silicate (KASIL SSR), available from PQ Corp.; - Sodium silicate GDR, available from PQ Corp .; - Zinc Borate (BOROGARD ZBR), available from U.S. Bórax Co.; - Anti-seizing and lubricant compound (NEVER-SEEZR) from Bostik.

First, approximately 25 ml of each of potassium silicate, sodium silicate, and zinc borate were mixed together for about 15 minutes to provide a homogenous, cushioned composition. Then a 75 ml sample of dry powder sample was added slowly to an amount of 250 ml of AM940126 to produce a gel with 30% damping agents per volume which produced a buffer range of pH 9-11. Then four sets of bare steel bolt / nut assemblies and four sets of steel bolt / nut assemblies with a zinc plate were prepared for the test. In all samples, the surface oxide layer and the corrosion initially present in the nuts / bolts were left unchanged. In addition, all samples were tested with nuts bolted to a midpoint on the bolts. The first set of bare steel bolt / nut assemblies and the first set of steel nut / bolt assemblies with zinc plate were designated as the control groups; consequently, no treatment was applied to these samples. The remaining three sets of the bare steel bolt / nut assemblies and the remaining three sets of zinc plated steel bolt / nut assemblies were prepared by coating each of the bolt / nut assemblies with pure gel AM940126 ( set 2), damped bel AM940126 (set 3), and NEVER-SEEZR (set 4). (NEVER-SEEZR contains hydrocarbon and heavy metal components and presents environmental considerations, its manufacturer claims that it protects against extreme heat, corrosion, rust, pitting, seizing and coal melting). These compounds were brushed on their respective pins to maintain a uniform coating that completely filled the threads. The nuts were then screwed into the bolts, and the excess material was removed by brushing. In the assembly, the threads on the end of the bolts, where the nuts have passed, were re-coated with the appropriate material. Then, the samples were exposed to a 5% saline solution in a constant temperature environment for 1464 hours (or until failure, whichever occurs sooner) according to ASTM Bll-73. The seizure was determined by manually checking the nuts for movement in the bolts. If more force was required to initiate the movement than what could be generated with the pressure of the fingers, the specimen was judged as having failed.

Table D Test part Hours of seizure * Bare steel control assembly 462 Naked steel assembly with 732 pure gel Naked steel mount with cushioned gel 1104 Naked steel mount with NEVER-SEEZR 1356 Steel mount clad with a zinc plate, control 816 Steel mount clad with a zinc plate with pure gel 2811 Steel mount clad with a zinc plate, with cushioned gel 2483 Steel mount clad with a zinc plate with NEVER-SEER 1598 * Average of the four samples per set The shock absorbing materials that were added to the synthetic polyalphaolefin gel AM940126 significantly extended the amount of time for the development of a seizure condition in the bare steel bolt / nut assemblies compared to the AM940126 material by itself and offered comparable performance to the commercial anti-seizure compound, which was tested. From an environmental point of view, the cushioned gel is superior to the commercial product. Three of the samples coated with a zinc plate with shock absorbing gels performed as well or better than the rest of the bare steel samples and those with a zinc plate. However, for reasons unknown in the sample coated with a zinc plate with buffered gel and in the sample coated with a zinc plate with NEVER-SEEZR, they significantly failed earlier than the other samples in their respective groups. This premature failure resulted in a lower average than expected for the cushioned assembly, lower than with the pure gel AM940126. However, both the AM940126 gel and the cushioned gel surpassed the NEVER-SEEZR material in the nut / bolt assemblies coated with a zinc plate EXAMPLE 3 The present materials were used: - Acrylic polymer NeoCrylRA640 from Zeneca Resins; - Texanol® ester alcohol (2, 2, 4, -trimethyl-1, 3-pentanediol) from Eastman Chemical; - BenzoFlex® 9-88 (Dipropylene Glycol Dibenzoate) from Velsicol Chemical Corp .; - Ethyl alcohol, Reactive Grade, available from Aldrich Chemical Co .; - Columbia D298 blue dye from Dy-Glo Color Corp .; - Sodium silicate liquid grade N from PQ Corp .; - Fittings equipped at the end with steel conduits electrodeposited with zinc. (Fabricated metal fittings, mounted on the ends of the parking brake cable duct assemblies).

A generic acrylic polymer formulation was prepared with the following components: wt% NeoCrylRA640 79.2 Texanol® 10.2 BenzoFlex® 9-88 1.4 Water 8.5 Ethyl alcohol 0.6 Blue dye Columbia D298 0.1 Approximately 15 ml of sodium grade N-silicate in 85 ml of the generic formulation of the acrylic polymer was added (mixed) slowly. A first group of assemblies equipped at the end with steel ducts coated with a zinc plate was immersed in a time, in the acrylic polymer formulation containing the liquid sodium silicate, and allowed to soak completely and air-dried during 24 hours. A second group of steel end fittings coated with a zinc plate from the same group of the metal plate coated attachments were once submerged in the generic formulation of acrylic polymer (not sodium silicate) that was allowed to soak completely and dried for 24 hours. In addition, a third group of steel end abutments coated with a zinc plate from the same group of the metal plate coated abutments were maintained for testing as a control. Six pieces from each of three attachment groups were subjected to the salt spray test ASTM-B117 and provided the following results.

GRUPO HORAS PROMEDIO AVERAGE HOURS FOR THE FIRST FOR 5% RED RED (FAILED) Only coated with a 36 56 Zinc plate Coated with a zinc plate with acrylic polymer coating 72 104 Coated with a zinc plate with acrylic polymer coating containing liquid sodium silicate 364 > 428 The addition of the liquid sodium silicate to act as a buffer according to the teachings of this invention produced approximately a 5-fold improvement in corrosion resistance. It should be understood that the foregoing is illustrative only and that other means and techniques may be employed without departing from the spirit or scope of the invention as defined in the following claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the present invention is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property:

Claims

1. A composition for inhibiting corrosion of a metal, characterized in that it comprises a carrier material adapted to cover the metal and containing a buffer or regulator material capable of damping the composition at a pH at which the metal has a natural passivity to corrosion.

2. The composition according to claim 1, characterized in that the carrier further comprises a viscous fluid capable of forming a permanent coating on the metal.

3. The composition according to claim 1, characterized in that the carrier further comprises a gel.

4. The composition according to claim 1, characterized in that the carrier material comprises an adhesive capable of adhering to the metal.

5. The composition according to claim 1, characterized in that the carrier comprises a polymer.

6. The composition according to claim 1, characterized in that the carrier comprises a synthetic polymer.

7. The composition according to claim 1, characterized in that the cushioning material is in the form of particles.

8. The composition according to claim 1, characterized in that the cushioning material is in the liquid form.

9. The composition according to claim 1, characterized in that the buffer material comprises an alkali metal silicate.

10. The composition according to claim 1, characterized in that the carrier material comprises a mixture of sodium and potassium silicates.

11. The composition according to claim 1, characterized in that it also comprises a material capable of reacting with the chloride ion to form a water insoluble precipitate.

12. The composition according to claim 1, characterized in that it also comprises a bactericide.

13. The composition according to claim 12, characterized in that the bactericide comprises zinc borate.

14. The composition according to claim 1, characterized in that it also comprises a fungicide.

15. The composition according to claim 2, characterized in that the carrier is capable of drying with air.

16. The composition according to claim 15, characterized in that the buffer is in a liquid form and the carrier comprises an aqueous polymer selected from the group consisting of water-reducible alkyds, modified alkyds, acrylic latexes, epoxy acrylic hydrates, epoxies reducible with water, polyurethane dispersions, vinyls and ethylene vinyl acetates.

17. The composition according to claim 3, characterized in that the gel has thixotropic properties.

18. The composition according to claim 1, characterized in that the carrier material additionally contains metal particles covered by themselves with the buffer material and a metal chloride.

19. The composition according to claim 18, characterized in that the metal chloride is zinc chloride.

20. The composition according to claim 1, characterized in that the carrier material additionally contains buffer particles covered by themselves with the buffer material and a metal tube.

21. The composition according to claim 20, characterized in that the metal chloride is zinc chloride.

22. A method for inhibiting corrosion of a metal, characterized in that it comprises covering the metal with a composition comprising a carrier material adapted to cover the metal and containing a cushioning material capable of damping the composition at a pH at which the metal has a natural passivity to corrosion.

23. A method for inhibiting corrosion of a metal, characterized in that it comprises coating the metal with at least one layer and a fluid carrier that cures to form a solid layer containing a cushioning material that damps the coating to a pH at which the metal has a natural passivity to corrosion.

24. The method according to claim 23, characterized in that the fluid carrier also contains a bactericide.

25. The method according to claim 23, characterized in that the fluid carrier also contains a fungicide.

26. The method according to claim 23, characterized in that it further comprises coating the metal with at least one layer containing a water repellent.

27. The method according to claim 23, characterized in that before coating the metal, the metal is coated with a metal plate with a metal selected from the group consisting of zinc, zinc alloy, zinc alloy containing chromate, and zinc alloy containing a chromate conversion film.

28. The method according to claim 23, characterized in that before coating the metal, the metal is covered with a compound selected from the group consisting of zinc phosphate, iron phosphate and manganese phosphate. 8

29. A method for inhibiting the corrosion of a cable containing multiple metallic wires, characterized in that it comprises covering the wires with a gel containing a buffer material that dampens the gel at a pH in which the metal wires have a natural passivity to corrosion.

30. The method according to claim 29, characterized in that the step of covering the wires includes injecting the gel into the cable.

31. The method according to claim 30, characterized in that the gel is thixotropic.

32. The method according to claim 30, characterized in that the gel comprises a pressure tolerance polymer.

33. The method according to claim 30, characterized in that the gel comprises a polymer selected from the group consisting of polyethylene, polyester, nylon and tetrafluoroethylene fluorocarbon.

34. A method for making or making a corrosion inhibitor for a metal surface comprising dispersing a dampening material in a carrier fluid capable of being applied to the metal to form a permanent shell, and wherein the cushioning material dampens the shell at a pH in which the metal has a natural passivity to corrosion.

35. The method according to claim 34, characterized in that the amount of absorbing material dispersed in the carrier fluid approaches a maximum consistent with the uniformity of the dispersion in the carrier fluid and with the application of the carrier fluid containing the buffer to the metal .

36. The method according to claim 34, characterized in that the carrier fluid comprises a synthetic polymer and the buffer material comprises sodium or potassium silicate.

37. The method according to claim 34, characterized in that the carrier fluid comprises a thixotropic gel.

38. The method according to claim 34, characterized in that the carrier fluid comprises an adhesive.

39. A method for inhibiting corrosion of a metal, characterized in that it comprises coating the metal with a carrier containing buffer particles of varying size which become active as buffers in the presence of moisture for a period of time and damping the coating at a pH at which the metal has a natural passivity to corrosion.

40. The method according to claim 39, characterized in that the buffer is comprised of sodium silicate or potassium silicate.

41. The method according to claim 39, characterized in that the buffer or regulatory particles are dissolved in aqueous liquid before inclusion in the carrier.

42. The method according to claim 41, characterized in that the carrier is comprised of a polymer selected from the group consisting of water-reducible alkyds, modified alkyds, acrylic latexes, acrylic-epoxy hybrids, water-reducible epoxies, polyurethane dispersions. , ethylene vinyl vinyls and acetates.

43. The method according to claim 39, characterized in that multiple layers of the carrier coating are applied to the metal.

44. The method according to claim 39, characterized in that it further comprises applying a barrier material on the buffer coating on the metal, wherein the barrier material is adapted to protect the buffer or regulator coating.

45. The method according to claim 39, characterized in that it also comprises applying a sealant on the barrier material.

46. A composition for inhibiting corrosion of a metal, characterized in that it comprises a carrier material containing particles of a buffer of variable size to provide release-time buffering at a pH at which the metal has a natural passivity to corrosion.

47. The composition according to claim 46, characterized in that the particles are dissolved in the liquid before inclusion in the carrier.

48. The composition according to claim 47, characterized in that the liquid comprises water.

49. A method for inhibiting metal corrosion, characterized in that it comprises: formulating a coating for the metal comprising a dampening or regulating material capable of damping the proximity of the metal in a pH range imparting natural passivity to the metal; and cover the metal with the coating.

50. The method according to claim 49, characterized in that the damping material is comprised of damping particles of variable size such that a release effect with time is obtained in the activation of the damping element.

51. The method according to claim 49, characterized in that the metal fibers used in the friction materials comprise the metal and the coating is applicable to the metal fibers by a dry spray technique, followed by the covering of the coating with a metal.

52. The method according to claim 51, characterized in that the friction material comprises a phenolic resin.

53. The method according to claim 51, characterized in that the metal chloride is zinc chloride which results in a zinc silicate film surrounding the coated metal when the buffer material comprises silicate.

54. The method according to claim 49, characterized in that the damping material is comprised of damping particles coated with the damping material by a dry spray technique, followed by a metal chloride coating.

55. The method according to claim 49, characterized in that the metal fibers used in the friction materials comprise the metal and the coating is applied to the metal by mixing the particles of the cushioning material with the metal fibers in a dry mixture before incorporation of the metal. the metallic fibers in the friction material.

56. The method according to claim 55, characterized in that the particles of the damping material are coated with the damping material and a film that is partially insoluble in water.

57. The method according to claim 55, characterized in that the friction material is comprised of a thermosetting phenolic resin.

58. An acro-infilled, micro-laminated coating system for inhibiting metal corrosion wherein the system comprises in the vicinity of the metal at least one layer of macro-infilled coating with absorbing, particulate, solid, dissolving material in contact with moisture to dampen the metal's proximity in a pH range in which the metal is naturally resistant to corrosion and this dissolution is dependent on the concentration gradient of the cushion material between the interior of the coating adjacent to the metal and the area surrounding the coating.

59. A wire characterized in that it comprises a plurality of metal cords and a rust inhibitor in the interstices between the cords and covering the cords, the rust inhibitor comprises a thixotropic gel containing particles of a buffering material which damps the gel at a pH of which the metal cords have a natural passivity to corrosion.

60. A method for treating small steel elements such as steel particles and fibers for use in the friction members of the brake, characterized in that it comprises: spraying or spraying a stream of an aqueous dispersion of a buffer or regulator material in one area to form a mist of the cushioning material in the area; maintain the zone at a temperature sufficient to evaporate the water from the buffer material; passing a gas stream containing the particles or fibers in the area to deposit the buffer material in the particles or fibers; vent gas and evaporated water from the area; recover the steel elements with the absorbing material deposited from the area; and additionally covering the steel elements with a partially water-insoluble film composed of metal chloride or metal silicate.

61. The method according to claim 60, characterized in that the damping material is capable, in the presence of humidity, of providing a pH at which the steel elements are naturally passive to corrosion.

62. Steel elements such as powders or fibers, characterized in that they are coated with a damping material capable of providing, in the presence of moisture, a pH at which the steel elements are naturally corrosive.

63. A friction brake member, characterized in that it contains a thermosetting resin containing steel elements such as powders or fibers coated with a damping material capable of providing, in the presence of moisture, a pH at which the steel elements are passive. natural way to corrosion.

64. The member according to claim 63, characterized in that it also comprises particles of a damping material capable of providing, in the presence of moisture, a pH at which the steel elements are naturally passive to corrosion.

65. The member according to claim 62 or 63, characterized in that the cushioning material comprises an alkali metal silicate.

66. A method for treating small steel elements such as particles and fiber for use in friction brake members, characterized in that it comprises: (a) passing a gas stream through a bed of steel elements under conditions to elevate these elements of steel in a contact zone above the bed; (b) spraying or spraying a stream of an aqueous dispersion of a shock absorbing material into the contact zone in intimate contact with the elevated steel elements to deposit the shock absorbing material on the steel elements; (c) maintaining the temperature of the contact zone at a level sufficient to evaporate the water from the buffer material; (d) venting the gas and water vapor in the area; (e) recover the steel elements with the buffer material deposited from the zone; and (f) covering the steel elements with a film partially insoluble in water.

67. A method for treating small steel elements for use in friction brake materials, characterized in that it comprises: contacting the steel elements with a vaporized aqueous dispersion of a damping material at a temperature sufficient to evaporate the water from the damping material and deposit the cushioning material on the steel elements; vent the vaporized water of the area; recover the elements with the buffer material deposited from the area, the buffer material that is selected to provide a pH, in the presence of moisture, in which the steel elements are naturally passive to corrosion; and covering the elements with a film partially soluble in water, comprising zinc.

68. A method for inhibiting corrosion of steel members used to reinforce concrete, characterized in that it comprises coating the steel members with at least one layer of a fluid that is curable to form a solid layer, the fluid containing a buffer that in the presence of moisture dissolves to provide a pH at which the steel has a natural passivity to corrosion.

69. A method for rehabilitating steel members used to reinforce concrete, after the members have begun to corrode, the method is characterized in that it comprises pumping in the cracks in the concrete a thixotropic composition containing a buffer which in the presence of moisture is dissolves to provide a pH at which the steel has a natural passivity to corrosion.