Weather-resistant epoxy acrylic

Weather-resistant epoxy acrylic 44 50 2 h 2-3 h Two components, topcoat, excellent weathering resistance, color and gloss retention, isocyanate-free... 

Selection of the prepolymer is guided by the desired film-forming properties. For example, acrylated epoxy resins typically provide hard, solvent-resistant films with fast cure at relatively low cost. Acrylated urethanes may be chosen for their excellent film flexibility and toughness. Aliphatic urethanes are used in preference to aromatic urethanes for stringent exterior weatherability requirements. The acrylated acrylics offer excellent nonyellowing properties when a soft film can be used. 

Silicone modification of alkyds, epoxies, acrylics and other coating resins are well-known for imparting improved gloss retention and weather resistance [1]. Copolymers of structure (Siloxane) = SiOCH2-(Resin) are prepared in organic solvents with relatively large proportions of silicone, since performance is approximately proportional to the silicone content. 

Polyester, epoxies, acrylics, vinyl esters, and silicones have aU been used in pultru-sion, but the largest percentage of the products are vinyl esters and polyesters because of their favorable costs, desirable properties, and easy handling characteristics. Liquid systems with low viscosity are used to ensure rapid saturation of the fiber bundles. The resin determines the weather resistance, thermal resistance, burning characteristics, moisture sensitivity, chemical resistance, and most of the electrical properties. 

Features Inc. hydrophobic and oleophobic props. improves weather resist., antigraffiti and tape release props. rec. in various binder systems (2-pack PU, alkyd-melamine, polyester-melamine, acrylic-melamine, acrylic-epoxy, phenolics) Properties Dens. 0.99 g/ml (20 C) hyd. no. 30 flash pt. 43 C Use Level 3-6% on total formulation Storage Reclose containers immediately after use BYK -UV 3500 [BYK-Chemie GmbH BYK-Chemie USA]... 

In the case of acrylic molding sheets and semi-fmished products, Wacker have elaborated a product concept based on silicone core-shell technology, which enables the manufacture of highly transparent particle-modified materials with improved RT and low-temperature (-40 C) impact resistance and high weatherability [4]. Other transparent plications (e.g., epoxy resins, polycarbonates) are showing encouraging results, too. 

Polyhydroxyurethane polymer usually has poor water resistance due to plurality of hydroxyl groups, but it is possible to prepare water-resistant materials in some formulations. For example, a cyclocarbonate acrylic was applied on a base of acrylic epoxy oligomer and a polymer was prepared with high water and weather stabilities... 

They are synthesized from polymers of primarily polymethacrylate, acrylate esters, and polyethyl acrylate (Fig. 13.2). Acrylate resins are very stable in oxygen and UV light and are resistant to weathering and frequently used in the automobile industry as topcoats. Water-based acrylics are used as household paints. For ultraviolet resistance and improved weathering, acrylic resins are used as modifiers for epoxy and alkyd coatings. 

Chem. Descrip. Fumed silica, aq. dispersion CAS 112945-52-5 EINECS/ELINCS 231-545-4 Uses Thixotrope, suspending agent for water-based acrylic, silicate, and alkyd polyesters coatings, some effectiveness in PUs/epoxies Features Corrosion resist., antisag/slump, and effective for weathering Properties Sp.gr. 1.10 00.15 vise. < 150 mPa-s pH 8.5-9.5 20 01% solids... 

Epoxy and polyester polyols, though more expensive than the acrylic polyols, are more chemically and moisture resistant. However, the acrylic polyol, when suitably reacted to form a urethane coating, is satisfactory for weathering atmospheres. 

The acrylic polyol when reacted suitably to form a urethane coating is perfectly satisfactory for most weathering environments. The isocyanate can be either aromatic or aliphatic. Up to the last 15 years or so aromatic isocyanates were most commonly used for urethane coatings. Since the aromatic urethanes are very similar in resistance to the epoxy family of coatings and their cost is higher, widespread use has not taken place. 

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