Curing modified acrylate systems

Polyurethane-acrylic coatings with interpenetrating polymer networks (IPNs) were synthesized from a two-component polyurethane (PU) and an unsaturated urethane-modified acrylic copolymer. The two-component PU was prepared from hydroxyethylacrylate-butylmethacrylate copolymer with or without reacting with c-caprolactonc and cured with an aliphatic polyisocyanate. The unsaturated acrylic copolymer was made from the same hydroxy-functional acrylic copolymer modified with isocyanatoethyl methacrylate. IPNs were prepared simultaneously from the two-polymer systems at various ratios. The IPNs were characterized by their mechanical properties and glass transition temperatures. 

Photopolymer Dielectrics The Characterization of Curing Behavior for Modified Acrylate Systems... 

UV-curing adhesives are available in a number of chemical systems, most of which are polymer based. These systems include acrylics and acrylates, epoxies, polyurethanes, polyesters, silicones, and vinyl and vinyl esters. The most common UV-curable adhesive is the acrylics. Specially modified acrylic and epoxy adhesives can be cured rapidly by UV radiation. In the case of epoxy adhesives, the adhesives can be pre-irradiated after application to the substrate before closing the bond line. These adhesive systems are offered by most major suppliers. ... 

Many epoxy dispersions are compatible with most types of latex emulsions including acrylic, urethane, styrene butadiene, vinyl chloride, and polyvinyl acetate. The epoxy dispersion can be used as a modifier for these emulsions to alter handling and application characteristics such as emulsion rheology, foaming tendencies, pH sensitivity, wetting properties, and coating coalescence. They can also be reacted into the latex resin either by reacting the epoxy with a functionalized latex or by use of an epoxy with a coreactant. In this way adhesive systems can be formulated that are cured at room or elevated temperatures. 

Table 1 shows the specifications of the concrete, carbon fiber sheet and adhesive resin investigated in the present work. The concrete blocks of 30 x 20 x 90 mm were made of normal grade Portland cement and cured in water for 4 weeks. The carbon fiber sheet (UT70-30, Toray) was a unidirectional cloth bound with a few lateral fibers. The adhesive resin (DK-530, Denka) was a modified acrylic resin of two component system. 

Acrylic concretes and mortars are used in applications which require fast curing. Acrylic crack-injecting systems are suitable for wet cracks. Products such as adhesives, asphalt modifiers and floor-care polymers find only a small percentage of applications. 

The acrylic resin used was Rohm and Haas Co.s QR-496 ( 4), so the exact nature of the polymer is not known. It is hydroxy functional, thus requiring an aminoplast for proper cure commercially modified hexa-methylol melamine resin was used for this purpose. During the first part of the investigation the acrylic resin was used without the melamine resin, but for final evaluation it was incorporated to give a more realistic commercial coating system. 

Considerable activity is underway to develop nontoxic activator and accelerator systems for these room temperature curing reactive adhesives. It is of interest to note that progress in analogous systems has been made in dental research - in work on acrylic adhesives for repair and for acrylic dentures. In one of several papers ( ), workers describe compositions of complex, exotic acrylic monomers cured with standard and modified Schiff s bases and with complex aromatic amines. 

Ariga (45) disclosed developments with CTBN-modified epoxy acrylates which when prepared with other lower molecular weight dicarboxylic acids and select carboxyl-terminated oligopolyesters serve as novel oligomers for photocurable coatings. These systems have low uncured viscosity. In the cured state they possess excellent scratch and crosshatch adhesion, good direct and reverse impacts (duPont impact tester) and pass bending diameters of 2 mm. 

Radiation Curing. The cross-linking of acrylate-modified polyester resins with U V radiation or an electron beam is an energy-saving alternative to the heat-curing systems. Reactive diluents (e.g., polyfunctional acrylates) are required to adjust the viscosity for application although they increase reactivity, they reduce the flexibility and substrate adhesion of the paint film. 

Chem. Descrip. Neodecanoic acid glycidyl ester CAS 26761-45-5 EINECS/ELINCS 247-979-2 Uses Epoxy modifier/diluent for coatings resins (esp. alkyds, polyester, acrylics), Epon resin-based electrodeposition binders, modified epoxy esters, UV-cured systems... 

Chem. Descrip. Amine-modified polyether acrylate oligomer Uses Sole binder or with monomer diluents or other oligomers in UV- and EB-cured systems, paper coatings, wood coatings Features Highly reactive very low vise. good hardness, chem. resist., adhesion... 

Chem. Descrip. PTFE-modified polyethylene wax Uses Surf, modifier, slip agent, abrasion resist, aid, mar resist, aid for wood finishes, UV-cured coatings, can and coil coatings, powd. and industrial coatings based on acrylics, alkyds, PU, NC and blends, epoxies, polyesters, hybrid systems... 

Uses Monomer for creating and modifying polymers, acrylic resins, urethane methacryiates marine antifouling paint resin comonomer reactive comonomer for acryiic and S/B resins rubber modifier binder for textiies/paper adhesives, nonwoven fabrics, enamels, adhesives grafting of textiie fibers scaie inhibitors adhesion promoter for polymers hydrophilic polymers It.-curing polymer systems reactive thinner for radiation curing food-pkg. adhesives, polymers Manuf./Distrib. Acros Org. Aldrich Allchem Ind. Ashland BP Amoco Electron Microscopy Sciences Fluka ICN Biomed. Research Prods. Kessler Lancaster Synthesis Laporte Perf. Chems. Monomer-Polymer Dajac Labs Pfaltz Bauer Rohm Haas Rohm Tech San Esters Scientific Polymer Prods. Sigma TCI Am. Ubichem pic Whyte Chems. Ltd... 

In general, the systems cured within one-half hour depending upon concentration of the catalyst and activator. No attempt has been made to optimize or further modify the systems. The results do indicate that with proper formulation the acrylated polyesters have potential as structural adhesives. 

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