Invented by David N. Walters, John R. Schneider, PPG Industries Ohio Inc
The global market for corrosion-resistant coatings is expected to reach $37.2 billion by 2025, according to a report by Grand View Research. The growth is driven by the increasing demand for these coatings in various industries, including oil and gas, marine, and construction. The report also highlights the growing trend of using eco-friendly coatings that are free from hazardous materials.
The market for coated substrates related to corrosion-resistant coatings is also growing. Coated substrates are materials that have been coated with a layer of corrosion-resistant coating to protect them from corrosion. These substrates are used in a wide range of applications, including automotive parts, construction materials, and electronic components.
The automotive industry is one of the largest users of coated substrates. Coated substrates are used in automotive parts such as brake systems, exhaust systems, and suspension components. These parts are exposed to harsh environments, including salt, moisture, and chemicals, which can cause corrosion. Coated substrates protect these parts from corrosion and extend their lifespan.
The construction industry is also a major user of coated substrates. Coated steel is commonly used in construction materials such as roofing, siding, and structural components. These materials are exposed to harsh environments, including rain, snow, and wind, which can cause corrosion. Coated substrates protect these materials from corrosion and extend their lifespan.
The marine industry is another major user of coated substrates. Coated substrates are used in marine equipment such as ships, offshore platforms, and pipelines. These equipment are exposed to harsh environments, including saltwater, which can cause corrosion. Coated substrates protect these equipment from corrosion and extend their lifespan.
In conclusion, the market for coating compositions with corrosion resistance properties and coated substrates related to them is growing rapidly. The increasing demand for these coatings is driven by the need to protect surfaces from corrosion and extend the lifespan of the substrate. The automotive, construction, and marine industries are the major users of these coatings and substrates. The trend towards eco-friendly coatings is also driving the growth of the market.
The PPG Industries Ohio Inc invention works as follows
Coating compositions that contain corrosion-resistant particles are disclosed, allowing the coating composition to exhibit corrosion resistance characteristics. A coating deposition from a coating composition is also disclosed, as are substrates that have been at least partially covered with the coating. Multi-component composites coatings where at least one layer of coating has been deposited later from this composition are also disclosed. “Methods and apparatuses for producing ultrafine solid particle are also disclosed.
Background for Coating compositions with corrosion resistance properties, and coated substrates related to them
Coating Systems that are deposited on a substrate, and then cured such as ‘color-plus-clear’ “Coating systems that are deposited onto a substrate and cured, such as?color-plus-clear? The environment can damage coating systems. As an example, if a metallic substrate is exposed in the air to oxygen and moisture, it can corrode. As a result, a ?primer? A coating layer is used to protect the surface from corrosion. Primers are often applied directly onto bare metal or metallic substrates that have been pretreated. In certain cases, especially when the primer is applied to a bare metal substrate, the primer is made from a composition containing a material such as an acid such as phosphoric, which increases the adhesion between the primer and the substrate. These primers are also known as “etch primers”.
As indicated, metallic substrates may be ‘pretreated’ in certain cases. Before a primer layer is applied, (if a primer is used), These ‘pretreatments’ are often used. Pretreatments often include the application and subsequent rinsing of a phosphate coating followed by the application of decorative or protective coatings. Pretreatments are often used to passivate metal substrates and increase corrosion resistance.
Historically, corrosion-resistant primers have been used. Coatings and metal treatments have used chromium and/or lead compounds to achieve the desired level of corrosion and adhesion with subsequently applied coats. Metal pretreatments use phosphate conversion compositions containing heavy metals such as nickel and post-rinses containing chrome. Compositions are also used to create a corrosion-resistant “primer”. Coatings often contain chromium. A primer composition of this type is described in U.S. Pat. No. 4,069,187. “The use of chromium or other heavy metals results in waste streams that present environmental concerns and disposal problems.
More recently, there have been efforts to reduce or eliminate chromium as well as other heavy metals. In order to combat corrosion, other materials have been added to coating compositions. Materials such as zinc phosphate and iron phosphate particles, zinc molybdate and calcium molybdate are some of the materials used. They have a particle size between a micron and a few millimeters. These compositions have a lower corrosion resistance than their chrome-containing counterparts.
It would therefore be desirable to provide compositions of coatings substantially free from chromium or other heavy metals. These compositions could, at least in some cases, have corrosion resistance properties that are superior to those of similar compositions without chromium. It would also be desirable to have methods of treating metal substrates (including bare metal substrates) to improve their corrosion resistance, which do not use chromium or other heavy metals.
The present invention is directed in certain respects to primers and/or coating compositions that include: (a) thermosetting resins formed by the reaction between a polyamine and an epoxy functional polymer, (b) corrosion-resistant particles consisting of magnesium oxide particles with a primary particle average size no greater than 100 nanometers.
The present invention, in some respects is directed towards aluminum substrates that are at least partially coated by a primer or pretreatment coating consisting of: (a) A thermoset film-forming polymer which is the reaction product between a polyamine functional polymer and an epoxy functional resin; (b) Magnesium oxide particles with an average primary particle diameter of no more 100 nanometers.
The present invention also relates methods for increasing the corrosion resistance on an aluminum substrate. These methods include coating at least a part of a metal substrate with a coating composition comprising: (a) a film-forming thermosetting polymer formed by the reaction between a polyamine and an epoxy functional polymer, and (b), corrosion resistant particles consisting of magnesium oxide particles with an average primary particle diameter of less than 100 nanometers.
The present invention, in certain respects is directed towards primer and/or coating compositions that contain: (a), a polyacrylate (b), a polythiol (c), corrosion-resistant particles consisting of magnesium oxide particles with an average primary particle diameter no greater than 100 nanometers.
For the purposes of this detailed description, the invention can assume different variations and sequences of steps, unless otherwise specified. In addition, except in operating examples or when otherwise indicated, any numbers used to express, for example quantities of ingredients in the specification and claim are to be interpreted as being modified by the term “about”. Accordingly, except where otherwise indicated, all numerical parameters in the specification and claims attached are approximate values that can vary depending on the desired properties of the invention. “At the very least, not to try to limit the application to the claims of the doctrine equivalents, each numerical parameter must be construed by using ordinary rounding techniques and the number of significant digits reported.
Although the numerical ranges or parameters that describe the general scope of the invention may be approximations in nature, the numerical values reported for the specific examples have been calculated as accurately as possible.” “Any numerical value will contain certain errors due to the standard deviation found in their respective test measurements.
It should also be understood that the numerical ranges cited here are intended to encompass all sub-ranges included within them. A range from?1-10? is an example. This range is intended to cover all sub-ranges that fall between the minimum value 1 and the maximum value 10, i.e., having a value less than or equal to 1 and a value greater or equal to 10.
In this application, singular and plural are used interchangeably, unless otherwise stated. This application, for example and without limitation refers to certain coating compositions which, in some embodiments, contain a “film-forming resin.” These references to “a film-forming resin” are intended to encompass coating compositions that contain one film-forming material as well as coating compositions that comprise a mixture of two or more filmforming materials. This term is intended to include coating compositions containing one film-forming material as well as compositions containing a combination of two or three film-forming materials. In this application,?or? means ?and/or? “?and/or?” means?and/or?” unless otherwise stated. “”Even though?and/or?
In certain embodiments the present invention is directed at coating compositions which are substantially free from chromium-containing material. In some embodiments, coating compositions are free from such a substance. The term “substantially-free” is used in this document. The material in question is only present as an accidental impurity if it’s at all. The material has no effect on the composition’s properties. In certain embodiments, the coating composition may contain less than 2 weight percentages of chromium-containing material. Or, in some instances, it could be less than 0.05 percent weight percent. The term “completely free” is used in this document. The term ‘completely free’ is used here to mean that the material does not exist in the composition. Certain embodiments of coating compositions in the present invention do not contain any chromium-containing materials. The term “chromium-containing material” is used in this document. Materials that contain a chromium trioxide group, CrO3, are included in the term. Examples of these materials are chromic acids, chromium oxides, chromic anhydride and dichromates such as sodium dichromate and potassium dichromate. Other examples include ammonium dichromate and calcium, barium magnesium zinc cadmium and strontium dioxide.
Certain embodiments of coating compositions are free from other undesirable materials such as heavy metals like lead and nickel. The coating compositions are free from such materials in certain embodiments.
As indicated, the coating compositions according to the present invention include?corrosion resistant particles? The term “corrosion resistant particles” is used in this document. Refers to particles that, when included in coating compositions that are deposited on a substrate act to provide coatings that resist or, in some instances, even prevent, the alteration of the substrate. For example, by a chemical or an electrochemical oxidizing processes, including rust or degradative oxides on aluminum substrates.
The present invention relates to coating compositions which contain corrosion resistant particles containing an inorganic oxid, or in some cases a number of inorganic oxids such as zinc oxide (ZnO), magnesium oxide (MgO), cerium oxide (CeO2) and/or molybdenum dioxide (MoO3). The term “plurality” is used in this document. The term?plurality? bedeutet zwei oder mehr. Certain embodiments of coating compositions according to the present invention include corrosion-resistant particles that comprise two, three or four inorganic oxidants. These inorganic oxides can be present in certain embodiments in the form a homogeneous solution or solid state solution.
In certain embodiments of coating compositions according to the present invention, corrosion-resistant particles containing an inorganic oxid, or in certain embodiments a plurality of them, contain an oxide of magnesium, zinc, cerium or yttrium. They may also include an oxide of aluminum, magnesium or tin. In certain embodiments the particles are an oxide of zinc, magnesium, cerium or calcium. In certain embodiments the particles may also contain an oxide of silicon, zirconium or iron. In certain embodiments the particles are silicon dioxide (also known as?silica ?).
The corrosion-resistant particles included in certain embodiments are composed of an assortment of oxides. These include oxides of cerium and zinc; oxides of calcium and zinc; oxides of phosphorous and zinc; oxides of yttrium and zinc; oxides of molybdenum and zinc; oxides of boron and zinc; oxides of boron and tin; and a combination of these oxides.
In certain embodiments, corrosion-resistant particles in the coating compositions are free or almost free of zirconium oxide. This means, in certain embodiments that the corrosion-resistant particles are less than 1 percent zirconium dioxide by weight or, in some instances, less than 0.05 percent zirconium.
In certain embodiments, the corrosion-resistant particles are composed of 10 to 25% by weight zinc oxide and 0.5 to 25% by weight cerium dioxide, with 50 to 89.5 % by weight silica. The percents by mass are calculated based on total weight. In some embodiments, these particles are free or almost free of zirconium.
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