Two-Component Acrylic Resins and Coatings

Two-Component Acrylic Resins and Coating Applications Resins are widely used in the paints and coatings industry, particularly as a protective layer against corrosion on metal, concrete and wood surfaces. Since 1996, our company has been a manufacturer of alkyd, saturated polyester, epoxy curing agents, polyaspartic and acrylic resins, supplying various resin types to the paints and coatings sector. Among these resins, acrylic resins are offered in two different types: thermoplastic and thermoset. Thermoplastic resins are high molecular weight polymers that soften with heat, take on the shape of the surface to which they are applied, and form a layer through solvent evaporation rather than through internal chemical reaction. Thermoset resins are developed by functional monomers that react with each other or with the functional groups of a crosslinker when exposed to heat or moisture to form a crosslinked film. After crosslinking, they provide films with good resistance to organic solvents, moisture and UV radiation. Acrylic monomers are polymerized using specific catalysts and initiators to create acrylic resins. In acrylic resin production, monomer ratios, dosing time, dosing rate, catalyst type, amount and temperature are the main variables affecting product quality. We produce thermoplastic resins used particularly in the coating of metal surfaces and as road marking paint. On the other hand, thermoset resins are increasingly used in industrial paint systems, marine paints and varnishes, furniture finishes and automobile repair systems due to their high yellowing resistance, high chemical resistance, high hardness and high impact strength.

Applications and Properties of Some Two-Component Acrylic Resins

Our thermoset acrylic resins manufactured in accordance with national and international standards, IZELCRYL 18B50 with 1.8% OH, IZELCRYL 26X60 with 2.6% OH and IZELCRYL 42B70 with 4.2% OH hydroxyl values, are used in obtaining crosslinked coatings. They react with isocyanates. The amount of isocyanate is determined according to the %OH value of the resin. Due to rapid yellowing and curing, the use of aromatic curing agents is not recommended for two-component acrylic resins. In systems created with aromatic curing agents, mechanical properties (yellowing, hardness, drying time, pot life, etc.) will change adversely. When curing with polyisocyanate, IZELCRYL 18B50 with 1.8% OH was developed as a hydroxyl functional acrylic resin for use in two-component systems. Industrial paint systems, furniture finishes and vehicle repair paints all typically use IZELCRYL 18B50 with 1.8% OH heat-curing acrylic resin. The product is preferred in the market due to its wide application range, fast drying time and high hardness, resistance to yellowing, strong adhesion and minimal isocyanate requirement. For paints and varnishes based on IZELCRYL 18B50 1.8% OH, selected solvents should not contain water and should not contain groups that react with isocyanates. IZELCRYL 26X60 with 2.6% OH resin is a thermoset acrylic copolymer with high heat and corrosion resistance, containing 60% solids and 2.6% hydroxyl groups. IZELCRYL 26X60 with 2.6% OH is used in industrial painting systems, furniture finishes and automobile repair primer and topcoat paints. Our IZELCRYL 26X60 with 2.6% OH resin, when used with isocyanate, is preferred for its many superior properties such as high adhesive strength, rapid drying, wide application range and corrosion resistance. IZELCRYL 42B70 with 4.2% OH is a hydroxyl functional acrylic resin developed for use in two-component systems and cured with polyisocyanate. IZELCRYL 42B70 with 4.2% OH acrylic resin is 70% solids and has 4.2 hydroxyl functional groups. It is frequently used in paint systems that require long drying times. Chemical resistance, high corrosion resistance and resulting high UV yellowing resistance make this acrylic resin a preferred choice. It is generally used in wood painting systems, marine varnish systems, industrial paint systems and vehicle maintenance paint systems. The adhesion performance of paints made from our resins to galvanized and sheet metal surfaces is given in Figure 1. Looking at Figure 1, it can be seen that the adhesion of our thermoset acrylic resins does not reach the cross-cut tape. Our resins, applied in thin film form at 60 microns thickness on a zebra card, were kept in a UV cabinet for 168 hours and their yellowing was examined. UV yellowing test results are given in Figure 2. Our resins, also used in industrial and automobile repair paint systems, have flexibility properties. Following the bending test in Figure 3, the coatings were examined for cracking or breaking. Looking at Figures 1, 2 and 3, our thermoset acrylic two-component resins are preferred in industrial and automobile repair paints due to their strong adhesion, absence of cracking after bending, impact resistance, yellowing resistance and high gloss properties.   Dr. Cemil Dizman - R&D Manager İzel Kimya   Levent Babayiğit - R&D Researcher İzel Kimya