Epoxy-Acrylates

Acrylated oils are a special type of epoxy acrylates. They are formed from epoxi-dized oils such as linseed oil, and (meth)acrylic acid. 

Another important class of modified epoxy resins, known as epoxy acrylates, are reaction products of a low MW epoxy resin and acrylic acid or methacrylic acid, which are used in radiation curable systems. The acrylate functionality is 2, but higher functionality variants can also be prepared by using epoxy phenol novolac in place of BPA epoxy resin. Radiation curable formulations from these oligomers provide a better balance of properties and cost compared to some of the alternative polymer systems. 

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Other examples of DAP copolymerizations of industrial interest include copolymerization with MMA in emulsion (50) and for light focusing rods (51) with vinyl naphthalene for lenses (52) with epoxy acrylates and glass fibers (53) epoxy acrylates and coatings (54) with diacetone acrylamide (55) with ahphatic diepoxide compounds (56) triaHyl cyanurate in lacquers for printed circuits (57) and DAIP with MMA (58). 

Earlier material systems were screened epoxies, but both laminatable dry-film and Hquid uv photoimageable coatings are finding wide acceptance. These radiation-cured coatings offer high resolution and registration accuracy, and can be either epoxies or epoxy acrylates. 

Electron-cured panel Hercules AS4, 5HS, 6K fiber, FW3 epoxy acrylate resin. 

The epoxy-acrylic resin referred to above is a graft copolymer prepared by the polymerisation of acrylic monomers in the presence of the epoxy resin in such a way that grafting of the acrylic onto the epoxy takes place. Water dispersibility is achieved by neutralising carboxyl groups in the acrylic polymer chain with ammonia or amine. Amino or phenolic resins are used as crosslinkers. Alternatively, solvent-borne epoxy-amino or epoxy-phenolic lacquers can be used. 

Unsaturated acrylic oligomers are made from unsaturated acrylic monomers. For example, an epoxy acrylate may be made by reaction of acrylic acid with epoxy resin. 

Although rolling and dipping are sometimes used, power spray painting is the usual method of paint application. Among the coatings used are polyurethane, epoxy, acrylic, alkyd and vinyl based paints. With paints that are oven cured, products must have sufficient heat resistance to survive without distortion, etc. 

Polyvinyl chloride has been modified by photochemical reactions in order to either produce a conductive polymer or to improve its light-stability. In the first case, the PVC plate was extensively photochlorinated and then degraded by UV exposure in N2. Total dehydrochlorination was achieved by a short Ar+ laser irradiation at 488 nm that leads to a purely carbon polymer which was shown to exhibit an electrical conductivity. In the second case, an epoxy-acrylate resin was coated onto a transparent PVC sheet and crosslinked by UV irradiation in the presence of both a photoinitiator and a UV absorber. This superficial treatment was found to greatly improve the photostability of PVC as well as its surface properties. 

Transparent PVC plates were coated with a 70 pm thick film of an epoxy-acrylate resin containing 0.5 % of a benzotriazole UV absorber. They were first UV cured for one second and then exposed at 40°C to the low intensity radiations of a QUV accelerated weathering tester. The extent of the degradation was followed by Invisible spectroscopy, a very sensitive method that permits detec-... 

Figure 9. UV-visible absorption spectra of a stabilized PVC plate, with or without a 70 yin UV cured epoxy-acrylate coating, before and after QUV aging at 40°C...

S02-cured epoxy resin. Modified epoxy/acrylic resins (1.2 to 1.4% of sand weight) are mixed with organic peroxide (26 to 60% of resin weight), the mixture is blown into the core box and a hardening mechanism similar to the S02 process takes place. 

Various finishes can be achieved — gloss, satin (or egg-shell) or matt. This is accomplished by the addition of particles of size 1-5 pm of, for example, silica, china clay or the white pigment, TiCK The degree of mattness depends on various factors, such as particle size, surface treatment of the particles, rate of film formation, and the polymer composition, e.g., urethane/acrylate compared with epoxy/acrylate. The former requires smaller particles larger particles cannot be used as they create a rough surface. 

Zinc Borate (2Zn0-3B203-3.5H20) is a unique multifuntional fire retardant. It can function as a flame retardant, smoke suppressant, afterglow suppressant, as well as an anti-tracking agent in polymers. It has been used extnesively as a fire retardant in PVC, polyolefin, nylon, polyester, epoxy, acrylic, urethane, rubbers, etc. 

Oligomers and Resins. Oligomers and resins used were Ebecryl 3700 epoxy acrylate, Radcure Specialties, Inc., Smyrna, GA 30080 Unicarb, which is 73% UVR 6128 (a cycloaliphatic epoxy), 26.5% polyol and 0.5% Silwet L-7602 (See under miscellaneous compounds), Union Carbide Chemicals and Plastics Co., Inc., Danbury, CT 06817-0001 and Heloxy 505 Modifier, Shell Chemical Co., Houston, TX 77210. 

Since the commercially available epoxy acrylate is extremely viscous, it is necessary to thin the formulation with a reactive diluent. A mixture with satisfactory viscosity for brush-on application contains about 45% diluent. Of the diluents tested, TMPTA (trimethylolpropane triacrylate) proved most successful. 

Epoxy acrylate BAPO/HMPP TMPTA 0 40 30 % pickoff 0 50 200g, No. 2 medium dense Least amount of rust... 

Epoxy acrylate, DIBFe,f TMPTA 5% 40 30 % pickoff 10 10 500g Few to medium no. 2 blisters A little rust around the edges Bleaching... 

Epoxy acrylate (Ebecryl 3700, 50%) combined with 25% TMPTA, 25% I BOA and with DIBF-OPPI-DIDMA pigment and FC-171 as above was also used to coat panels. These panels showed no removal of coating in the cross hatch adhesion test. With 6.8j there was no loosened coating on the frontal impact surface, and only 30% was loosened on the back surface. Five hundred grams were required to scratch to bare metal with the balanced beam. Performance was... 

Epoxy acrylates, 10 382-383 in varnish formulations, 10 442 Epoxy activation, in microarray fabrication, 16 385... 

Radiation-curable epoxy acrylates, 10 450 Radiation cures, silicone network preparation via, 22 567-569 Radiation curing coatings, 7 133-135 of printing inks, 14 314 Radiation damage, ion implantation and, 14 435-436 Radiation drying coatings, 7 29-30 Radiation effects... 

Joining is possible with adhesives such as epoxies, acrylates, cyanoacrylates, polyurethanes. Surface treatments can be useful. Preliminary tests are essential. 

UVC Lacquer and Test. A white epoxy-acrylate lacquer was applied on all nickel plated sheets with different pretreatments to a thickness of 16 ym and was cured by irradiation with four 10-kW ultraviolet lamps for about 1.2 sec. 

Epocryl Epoxy acrylate resins Shell Chemical... 

Epoxy acrylates. The most widely used oligomers are aromatic and aliphatic epoxy acrylates. Epoxy acrylates are highly reactive and produce hard and chemically resistant films. The polymerization of monoacrylates produces linear polymers,... 

Figure 2. Normalized thickness of the polymerized epoxy-acrylate film versus duration of the exposure to the argon-ion laser beam (A in N2, in air) or to conventional UV radiation (O in air).

Figure 4. Kinetics of the polymerization of polyester- and epoxy-acrylate photoresists under pulsed laser irradiation at 337.1 nm in the presence of air.

Figure 6. Dependence of the polymerization quantum yield ( ) on the light-intensity (Iq) in the laser-induced polymerization of epoxy-acrylate photoresists (— expected variation of on I0 for a half-order kinetic law).

The most important monomers (> 95 % by weight) for silicone synthesis are the methyl chlorosilanes. Next to them are the phenyl chlorosilanes, methyl phenyl chlor-osilanes, methyltrifluoropropyl chlorosilanes, and a variety of silanes containing organic functional groups such as hydroxyl, amine, epoxy, acrylate and carboxyl which are responsible for the different products. 

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