Abrasion resistant epoxy

High-build abrasion-resistant epoxy Acid-resistant epoxy High-build, recoatable epoxy Solvent-free epoxy 1... 

High buiid abrasion resistant epoxy 88 250-500 3 h 16 h Amine-adduct-cured, giass-fiake-reinforced... 

The abihty of organically modified ceramics based on alumina, zkconia, titania, or siUca (and mixtures of each) to function as abrasion-resistant coatings has also been studied (62). Eor example, polycarbonate, when coated with an epoxy—aluminosihcate system, experiences a significant reduction in the degree of hazing induced by an abrader, as compared to uncoated polycarbonate. 

Epoxies provide excellent chemical, moisture, and abrasion resistance. However, because a solvent can sometimes dissolve the epoxy present in the laminate, rework on an epoxy coating requires heat or abrasion to remove the coating. 

Powder Costings. Epoxy-based powder coatings exhibit useful properties such as exceUent adhesion, abrasion resistance, hardness, and chemical resistance. The appHcation possibUities are diverse, including refrigerator liners, oU filters, hospital equipment, primers, shelving, automobUe springs, and fire extinguishers. 

Epoxy resin paints, inferior to chlorinated rubber for resistance to strong acids, are excellent for dilute acids and strong alkalis. They produce a harder, more abrasion-resistant coating than does chlorinated rubber and are much better for resistance to fats, oils and many organic solvents. Table 3.50 gives data on the chemical resistance of epoxy resin coatings to different materials. 

When formulating a system for optimum abrasion resistance, both the epoxy/resin hardener binder system and the filler blends used appear to have an influence. The simulation of abrasive service loads on industrial floor toppings in a laboratory is not simple, and numerous wear test machines have been devised. Correlation between different wear test machines is not always good, although most... 

In one series of laboratory tests carried out to find the optimum wear resistance of heavy-duty epoxy resin flooring compositions, a number of different abrasion resistant materials were evaluated using BS 416, employing three different epoxy resin binders which themselves had significantly differing chemical compositions and mechanical properties. The results of this work, which was carried out under dry conditions, are given in Table 9.1. As can be seen from the table, the selection of the abrasion-resistant material and the resin matrix both influence the abrasion resistance of the system, although the abrasive material incorporated appears to play a more cmcial role. 

Two-pack polyurethanes Also called urethanes, these materials are similar to two-pack epoxies in that they can be formulated to provide different properties. They can be made into foams or soft, rubbery materials, as well as very hard, tough, abrasion-resistant coatings. 

Solventless urethanes These are similar to solventless epoxies but can be applied in even thicker films without adhesion problems. They are considered to have better water and abrasion resistance than the epoxy but cost more and application is even more critical. Their main use would be for large areas requiring abrasion resistance. 

Thermosetting epoxy and polyurethane chemically-cured liquid resins can provide, among other characteristics, superior abrasion resistance coatings. Solvent-free formulation applied by hot spray techniques can achieve film thicknesses of up to 5 mm. 

Epoxy-silica hybrids are well known for their abrasion resistance and low thermal expansion due to the presence of nanostructured bi-continuous domains. Most recently they have entered the market as anticorrosion coatings in the marine held, for yachts and for large metal vessels, such as oil tankers, and in particular for cargo or ballast tanks and on hulls (Figure 4.9). 

Many of the attributes of solvent-borne epoxy coatings could be carried over to the waterborne epoxy coatings. These same attributes are useful in the application of waterborne epoxies as adhesive systems. They include good adhesion to a variety of substrates such as metals, wood, concrete, glass, ceramics, and many plastics chemical resistance low shrinkage toughness and flexibility and abrasion resistance. 

Selecting the appropriate glove materials with epoxy resins systems involves matching the characteristics of the glove with the requirements of the production task. Glove resistance characteristics can be classified as either physical or chemical. Physical characteristics of production tasks are dexterity wet grip and cut, tear, puncture, and abrasion resistance. Chemical characteristics are dependent on the aggressiveness of the resins, solvents, and other materials. 

There are RIM systems based on chemistry unrelated to polyurethanes that are not in significant commercial production compared to the polyurethanes. Development work has taken place with materials such as nylon. The nylon RIM material is based on caprolactam. Nylon RIM polymers offer high toughness and abrasion resistance. Polydicyclo-pentadiene is a proprietary thermoset polymer developed by Hercules. PCPD offers high-impact resistance and stiffness. It is used in the production of snowmobile components. Other polymers are used such as epoxies, polyesters, acrylics, phenolics, and styrenics. 

Textile chemical auxiliary suppliers will provide suggested recipes in their product information. These recipes will contain recommendations for the appropriate catalyst and other additives that improve the performance characteristics of the easy-care and dnrable press finishes, such as softeners to improve the fabric handle and prodncts to improve tear strength (for example polyvinyl acetate, amino-modified or epoxy-functional silicones). Less decrease in degree of polymerisation (DP) rating and abrasion resistance is provided by adding water-based poly-nrethane emulsions of self crosslinking silicone elastomers. 

The urethane linkage is a relatively stable bond. Owing to the availability of many types of urethane compound it is possible to create hundreds of potentially interesting products which are characterised by toughness, chemical and corrosion resistance, abrasion resistance and durability. This combination of properties is hard to match in a single resin, with the exception of epoxies. 

Epoxies have an excellent resistance to abrasion. The abrasion resistance of a particular system depends upon the type of formulation and conditions. For example coatings have the capacity to resist abrasion from rubber wheels, whereas screed floorings, repair mortar and self-levelling floors can resist thousands of cycles from steel wheels. 

It is also possible to formulate epoxy coatings by using glass flakes. This improves the abrasion resistance. Such coatings can be applied at a dft of between 1500 xm and 3000 xm (International Paints, 1996). 

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