Acrylic radiation curing

An interesting modification involves expandable monomers. These materials, synthesized by Dr. William J. Bailey and coworkers at University of Maryland, are spiro monomers, double rings which open and expand on polymerization. They can be useful in adhesives which are based on polymer/monomer solution, such as structural acrylics, radiation-cured acrylates, etc. These monomers can counteract shrinkage on curing, which is detrimental to adhesion. 

Reactive other Urethane acrylates (radiation cure) Solvent-free Wood coatings, adhesives for GRP (glass reinforced plastics)... 

Reactive hot melt polyurethane Epoxies Cyanoacrylate Anaerobics Reactive acrylics Radiation-cured adhesives. 

Methacrylate adhesives Cyanoacrylates Anaerobic adhesives Unsaturated polyester adhesives Acrylates (radiation cure)... 

Higher alkyl acrylates and alkyl-functional esters are important in copolymer products, in conventional emulsion appHcations for coatings and adhesives, and as reactants in radiation-cured coatings and inks. In general, they are produced in direct or transesterification batch processes (17,101,102) because of their relatively low volume. 

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. 

The tensile strength of NR compounds in the presence of cross-link promoters such as dichlorobenzene is increased as compared to the sulfur-accelerator and peroxide-curing systems. The retention of the maximum tensile strength at elevated temperamres is greater for radiation cured than for chemically vulcanized NR [326,327]. Also reported are a higher abrasion resistance [328] and a lower flex life in the case of radiation-cured system. Effect of phenoxy ethyl acrylate (PEA)... 

The pits are generally embossed into the substrate (polycarbonate or polymethylmethacrylate) layer by an injection-molding process, and are used to indicate whether a data bit is 0 or 1. An aluminum or silver layer provides a reflective surface, and is protected from corrosion and damage by a radiation-cured acrylate (lacquer) layer, onto which a label is usually printed.197... 

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... 

Tensile strength of radiation-cured purified natural rubber Tensile strength of radiation-cured purified natural rubber Examples of industrially important acrylated prepolymers The arrangement for direct roll coating Different types of cells on the surface of a gravure roll Reverse roll coating... 

Acrylic resins - [MAGNESIUMAND MAGNESIUM ALLOYS] (Vol 15) - [COATING PROCESSES - POWDER TECHNOLOGY] (Vol 6) -photocuring [RADIATION CURING] (Vol 20) -plasticization of [PLASTICIZERS] (Vol 19) -thiols m [THIOLS] (Vol 24)... 

There are basically two types of epoxy acrylate resins used in formulating adhesive systems. One is a vinyl ester resin that is used in two-component adhesive formulations much as a DGEB A epoxy or a polyester resin is. The other is a special type of resin that is used in radiation cure processes. This latter type of epoxy acrylate does not have any free epoxy groups, but reacts through its unsaturation. 

Epoxy acrylates are also commonly used as oligomers in radiation-curing coatings and adhesives. However, their name often leads to confusion. In most cases, these epoxy acrylates have no free epoxy groups left but react through their unsaturation. These resins are formulated with photoinitiators to cure via uv or electron beam (EB) radiation. The reaction mechanism is generally initiated by free radicals or by cations in a cationic photoinitiated system. The uv/EB cured epoxy formulations are discussed in Chap. 14. 

Radiation curing adhesives are generally applied as solvent-free liquids. High-solids EB and uv curing liquid adhesives have been formulated from a variety of resins and elastomers. They include epoxy acrylates, epoxies, other acrylates, polyesters, blends of acrylate monomers with elastomers, and other compositions. 

Most of the radiation curable raw material technology is based on acrylic or methacrylic acid deritive but may also include modified epoxies, polyesters, and polyurethanes. Thus the backbones of radiation curing and conventional coatings are similar. 

Recently, hot melt PSA systems have been introduced and radiation curable PSA systems are at the commercial development stage. High solids (50%-70% by wt.) nonaqueous dispersion acrylic PSA systems have also been reported(1). Unlike the hot melt and radiation cured systems which require new capital outlay in coating head and/or curing (drying) equipment, BFG has developed PSA systems, based on Hycar 2100R reactive acrylic liquid polymers and isocyanate terminated prepolymer, which can be processed at 80% solids (by wt.) with equipment presently used in the PSA industry, namely, the reverse roll and knife-over-roll coater. 

McGinniss, V. C., "Photoinitiator of Acrylate Systems for UV Curing," 3rd International Radiation Curing Conference, Proc. of SME Radiation Curing Conference, FC76-486 (1976). 

Pentaerythritol and trimetkyiolpropane acrylic esters are useful in solventless lacquer formulations for radiation curing (qv), providing a cross-linking capability for the main film component, which is usually an acrylic ester of urethane, epoxy, or poly7ester. Some specialty7 films utilize dipentaerythritol and ditrimetkylolpropane (94,95). 

Pacansky et al. (1987) described the fabrication of dual-layer photoreceptors by radiation curing. The layers were coated with a polymerizable acrylate monomer or oligomer as the liquid component, then cured by a 175 kV electron beam or ultraviolet exposure. These methods were used for the preparation of generation layers containing bisazo and hydroxysquaraine pigments. 

A hard coat sheet comprises a transparent base sheet, and a radiation-curing acrylate coat layer including an antibacterial agent provided on the transparent base sheet. Thus, the hard coat sheet has excellent transparency and antibacterial property together with an excellent scratch resistance property. 

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