Epoxy polyamide primers

Epoxy based primer systems remain the best suited for the corrosion protection of magnesium. Cathodic epoxy electrophoretic paints , chromate inhibited epoxy-polyamide primers and high temperature stoving epoxy sealers are used to provide protection up to 180°C. For higher temperature applications up to 300°C, epoxy silicone or polyimide based systems can be used. 

Wedge test results suggest that the curing process (e.g., percent crosslinking) of the epoxy-polyamide primer system is not affected by the addition of organosilanes, but may be affected by NTMP. The results of substrate surface characterization, adsorption behavior of applied films, and evaluation of candidate inhibitors by chemical, mechanical, and electrochemical test methods are presented. Mechanisms to explain the observed behavior of the various phosphonate and silane polymer systems are discussed. 

Primer Epoxy vs. Nitrile-Modified Epoxy. The compatibility of the epoxy-polyamide primer with the nitrile-modified epoxy adhesive facsimile and the aluminum oxide surface was also evaluated by the wedge test, since earlier tests using the primer as the adhesive had failed immediately. As shown in Fig. 8, the addition of the primer directly to the prepared... 

The corrosion resistance and polymer-bonding compatibilities of the lonizable organophosphonates and the neutral organo-silanes are directly related to their inherent chemical properties. Specifically, NTMP inhibits the hydration of AI2O2 and maintains or Improves bond durability with a nitrile-modified epoxy adhesive which is cured at an elevated temperature. The mercaptopropyl silane, in addition to these properties, is compatible with a room temperature-cured epoxy-polyamide primer and also exhibits resistance to localized environmental corrosion. These results, in conjunction with the adsorbed Inhibitor films and the metal substrate surfaces, are subsequently discussed. 

Adsorbed NTMP exhibits a pH-dependent surface coverage on anodized aluminum, which Includes a region characterized by a multilayer of hydrogen-bonded phosphonate molecules. These thick layers are weak and fall to provide good bond durability in a humid environment. NTMP monolayers are protective against hydration and are compatible with a nitrile-modified epoxy adhesive, but not with an epoxy-polyamide primer topcoat. 

Abstract The incorporation of rare earth compounds as corrosion inhibitors in polymeric paint systems is presented. Specifically, uses of cerium salts in an electrolytically deposited coating commonly used in the automotive industry and praseodymium oxide in spray applied epoxy-polyamide primers for aerospace applications are discussed. Special emphasis is placed on the importance of phase of the rare earth material in relation to polymeric matrix as the effectiveness of the corrosion inhibition is strongly link to the starting materials, the formulated paint system and the ambient environment in which the coating operates in practice. 

Key words praseodymium, cerium, epoxy polyamide primer, eCoat, phase stability, corrosion protection mechanism. 

Praseodymium-based inhibitors in epoxy polyamide primers... 

In the freeboard areas, commercial ships use organic 2inc-rich primers extensively and usually topcoat them with a two- or three-coat epoxy system. U.S. Navy ships use an organic 2inc-rich primer, two to three coats of an epoxy-polyamide coatings, and a siUcone-alkyd topcoat (16) the entire dry system is 150—225 )J.m thick. 

Organic zinc-rich primers are based on epoxy/polyamides, high-molecular-weight linear epoxies, moisture-cured urethanes, high-styrene resins, chlorinated rubbers and epoxy esters. In this type of primer zinc is covered with a monomolecular layer of the binder which facilitates the adhesion of the film to the substrate. 

Chem. Descrip. y-Ureidopropyltrimethoxysilane CAS 23843-64-3 EINECS/ELINCS 245-904-8 Uses Adhesion promoter aiding bond between fillers and reinforcements (e.g., fiberglass, particulates, metals) and various polymers (phenolic, urea-melamine, epoxies, polyamide, PU), for use in glass fiber sizes and finishes, wool insulation resin binders, primers, foundry sand binders, adhesives, sealants, and abrasive grinding wheel binders Features Contains no flamm. or combustible solv. low VOC emissions Properties Lt. straw clear liq. sol. in methanol, ethanol, acetone, toluene, methyl Cellosolve, water m.w. 220 sp.gr. 1.15 b.p. 217-250 C (700 mm Hg) flash pt. (TCC) 99 C ref. index 1.386 100% act. Silquest Y-11597 [OSi Spec.]... 

Uses Adhesion promoter aiding bond between fillers and reinforcements (e.g., fiberglass, particulates, metals) and various polymers (phenolic, urea-melamine, epoxies, polyamide, PU) used in glass fiber sizes and finishes, wool insulation resin binders, primers, foundry sand binders, adhesives, sealants, and abrasive grinding wheel binders low VOC emissions... 

VOC reducer, epoxy polyamide topcoats Boroslllcate glass VOC reducer, paints/coatings Borosilicate glass VOC reducer, primers Borosilicate glass... 

Combinations of zinc dust (particle diameter 12-20 xm) and extrafine zinc dust (particle diameter 3-6 p,m) yield optimal corrosion resistance. Small amounts of aluminum paste or powder, added to obtain a more silvery appearance, will however decrease corrosion resistance—as found in comparative weathering tests by Van Eijnsbergen (personal communication). Generally, nonsaponifiable binders, such as vinyl copolymers, chlorinated mbber, methacrylic resins, and epoxy resins, are used. For welding zinc-rich primers, epoxy-polyamide binders are widely used. They allow a wider range of sealers and top coatings. 

Paint 22 Epoxy-Polyamide Paints (Primer, Intermediate, and Topcoat)... 

For qtplications involving outdoor exposure, a surface treatment such as anodizing or chemical conversion coating is required prior to the application of a primer and a finish (top) coat, such as an epoxy or polyurethane. Some new one-step, self-priming polyurethane top coats are also available as are low volatile-organic compound (VOC) high-performance primers (e.g., epoxy polyamide). 

Suitable paints for use underwater include vinyl resin systems, coal tar paints over inorganic zinc-rich primers, and some coal-tar epoxy primers have also proved themselves Special paints are available for application under water, e.g. epoxy modifications with polyamides. 

Polyamide (nylon) Acetone, methyl ethyl ketone 1. Abrasion. Grit or vapor blast or abrade with 100-grit emery cloth followed by solvent degreasing. 2. Prime with a spreading dough based on the type of rubber to be bonded in an admixture with isocyanate. 3. Prime with resorcinol formaldehyde adhesives. Sand or steel shot is suitable abrasive Suitable for bonding polyamide textiles to natural and synthetic rubbers Good adhesion to primer coat with epoxy adhesives in metal-to-plastic joints... 

In addition to FRP and adhesives, a third important use of epoxy resins in aerospace is in surface coatings. Epoxy resin-polyamide combinations are used as primers under urethane top coats. The most... 

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