Solvent-free epoxy

Self-leveling These are generally based on solvent-free epoxy and there are a number of proprietary products available. Generally, they are 3-8 mm thick, but if the base floor is too rough, it is advisable to first level this with a cement/resin screed. 

While unaffected by water, styrofoam is dissolved by many organic solvents and is unsuitable for high-temperature applications because its heat-distortion temperature is around 77°C. Molded styrofoam objects are produced commercially from expandable polystyrene beads, but this process does not appear attractive for laboratory applications because polyurethane foams are much easier to foam in place. However, extruded polystyrene foam is available in slabs and boards which may be sawed, carved, or sanded into desired shapes and may be cemented. It is generally undesirable to join expanded polystyrene parts with cements that contain solvents which will dissolve the plastic and thus cause collapse of the cellular structure. This excludes from use a large number of cements which contain volatile aromatic hydrocarbons, ketones, or esters. Some suitable cements are room-temperature-vulcanizing silicone rubber (see below) and solvent-free epoxy cements. When a strong bond is not necessary, polyvinyl-acetate emulsion (Elmer s Glue-All) will work. 

Glycidyl ethers of aliphatic polyols based on polyglycol, glycerin, and other polyols are flexible epoxy resins. They are used as reactive diluents and flexibihzers for solvent-free epoxy resin formulations. Epoxy-polyglycol resins that are produced from the reaction of epichlorohydrin and polyester polyols based on ethylene or propylene oxide are the most common of these types of flexible epoxy resins. Examples of typical commercial aliphatic epoxy resins are shown in App. C. 

Solvent-free epoxy (spray or trowel) 100 500-625 2 h 6h High resistance against tidal and impact actions, good oil and water resistance, good adhesion to many surfaces... 

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

Water-based decorative wall paint Low-viscosity solvent-free epoxy sealer 42 100 38 15 min 2 h 16 h Flat, decorative finish on walls and ceilings, for interior and exterior use Excellent penetrating sealer and adhesion promoter for concrete and prior to application of coatings, excellent chemical resistance... 

Figure 10.9 The reaction pattern for epoxy-polyurethane modifications. Source Wellner, W., Gruber, H. and Ruttmann, G., New solvent free epoxy/polyurethane combinations, publication E 908-8122/850640 published by Bayer AG, Plastics and Coatings Division, D-5090, Leverkusen...

Solvent-free epoxies are much more expensive than coal-tar epoxies or the solvent-borne epoxies previously used in ship construction. Most of the cost in coating a ship is in the cost of grit blasting the steel followed by applying coating. Coal-tar epoxies of solvent-borne epoxies cost 1.80 and 2.80 per square meter while solvent-free epoxy cost 6.60 per square meter. For the amount of coating needed to coat a ship, it will cost 150,000 more than coal-tar epoxy and 120,000 over solvent-borne epoxy. The cost of ship is around 70-80 million, and the use of solvent-free epoxy is not significantly expensive. 

The application of solvent-free epoxy has a longer life than coal-tar epoxy, and coal-tar epoxy has to be applied two to three times compared to only one time in the case of solvent-free epoxy coating. To perform recoating, the tanks have to be cleaned... 

To prevent corrosion of double-hulled tanks, coatings with corrosion resistance at temperatures of 70-90 C and resistance to MIC as well as resistance to acid attack in the ullage were found desirable. Because of the flexing of HT steel, the coating needs to be flexible and does not become brittle and break off over time as the ship flexes. The coating should last for 20 years. Solvent-free epoxies satisfied these requirements. 

Coatings such as modified epoxies, coal-tar epoxy, or solvent-borne epoxy have been used by many shipbuilders since 1998. The problem with these coatings is that the lifetime of these coatings is such that they can give protection for only 8-10 years, which is less than the design life of the vessels. These coatings are not resistant to the temperatures in double-hulled tankers and the bacteria that causes pitting corrosion on the bottom of tanks. The use of solvent-free epoxy on the top and bottom of a crude tanker should prevent corrosion of the tanker. 

Solvent-free epoxy systems must be applied within an extremely short time (30-60 min), which presents problems, particularly in hot countries. Such systems are also frequently applied with heatable two-component spraying equipment. Keti-mines give a longer pot life. They are produced by condensing ketones and polyamines (Epikure H 3, Shell). When applied as a thin layer, they react with atmospheric moisture and are converted back into the ketone and polyamine. The ketone evaporates from the film and the amine cross-links the epoxy resin. Ketimines can only be used if a sufficiently high ambient temperature (>20 C) and high atmospheric moisture (>75% R. H.) can be guaranteed. 

Floor Coatings. Concrete floors are coated with low-solvent or solvent-free epoxy or acrylic resin materials that may be applied in any desired thickness. They are extremely resistant to abrasion, can be made slip resistant with sand, silicon carbide, or high-grade steel granulate, and are also resistant to mineral or vegetable oils and gasoline (used for warehouses and factory halls). 

Crayvallac MT Flowtone GST antisettling agent, solvent-free epoxies... 

Additol XW 335 hardener, cold-curable solvent-free epoxy... 

ASP RO Butrol 22 Methyltrlmethoxysllane pigment, solvent-free air-dry paints Additol XL 251 pigment, solvent-free epoxies Trihydroxystearin... 

Keltrol CG BT Keltrol CG F Keltrol CG RD Keltrol CG T Keltrol CG suspending agent, pigments solvent-free epoxies... 

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