Adhesives solventless

Chem. Descrip. Trifunctional polyester acrylate oligomer Uses Diluent for UV/EB-cured prods., flexographic and screen inks, coatings (paper, wood, plastics), paper upgrading, high vise, systems, EB-cured paper-foil laminating adhesives, solventless spray and ttow coaler applies. 

There are three basic categories of adhesive bonding used, each requiring specific equipment. Selection of a particular technique depends on the nature of the substrates used and final application. There are a considerable number of adhesive laminating materials and techniques or variants upon the theme, but it can be reduced to the three basic types of material, aqueous based (see Emulsion and dispersion adhesives), Soivent-based adhesives, solventless 100% solids or Hot melt adhesives, and to the two basic techniques, wet and dry lamination. 

Abocast, Casting compounds, encapsulants, adhesives (solventless), Abatron, Inc. 

Sihcone products dominate the pressure-sensitive adhesive release paper market, but other materials such as Quilon (E.I. du Pont de Nemours Co., Inc.), a Werner-type chromium complex, stearato chromic chloride [12768-56-8] are also used. Various base papers are used, including polyethylene-coated kraft as well as polymer substrates such as polyethylene or polyester film. Sihcone coatings that cross-link to form a film and also bond to the cellulose are used in various forms, such as solvent and solventless dispersions and emulsions. Technical requirements for the coated papers include good release, no contamination of the adhesive being protected, no blocking in roUs, good solvent holdout with respect to adhesives appHed from solvent, and good thermal and dimensional stabiUty (see Silicon COMPOUNDS, silicones). 

Advantages are similar to the epoxy system, in that these can be solventless and do not require thermal energy. Disadvantages unique to this system, however, include the need to inert the cure chamber to avoid air-inhibition of cure as well as some release instability with acrylate adhesives [72]. 

Solventless urethanes These are similar to solventless epoxies but can be applied in even thicker films without adhesion problems. They are considered to have better water and abrasion resistance than the epoxy but cost more and application is even more critical. Their main use would be for large areas requiring abrasion resistance. 

The applications of epoxy resins are not only used for adhesives but in the area of coatings used for appliances, automobiles, and cans. These resins have the added advantage of being solventless systems, which helps avoid air pollution... 

Adhesives, Cyanoacrylate, Rapid Room Temperature Curing, Solventless, Anny Materials and Aleckanics Research Center, Watertown, Mass. 

First-generation solventless polyurethane adhesives are one-component isocyanate terminated prepolymers formed by the reaction of MDI (4,4 methylene bis (phenyl isocyanate)), or other isocyanates with polyether and/ or polyester polyols. One-component 100% solids adhesives rely on moisture from the air or substrates or from induced moisture misting during the converting process, to cure the adhesive via an isocyanate/water reaction and subsequent polyurea-polyurethane polymer formation. Typically the high viscosity of the adhesive is such as to require adhesive delivery equipment and application rollers heated from 65-80 °C for use. They have a high level... 

Second-generation solventless polyurethane adhesives Two-component second-generation adhesive systems are the most widely used of the 100% solids products. These two-part adhesives comprise an isocyanate terminated prepolymer based on the reaction product normally of MDI and polyols (polyether or polyester) in the presence of excess isocyanate, and a polyol (polyether or polyester based). 

Components of solventless polyurethane adhesives Aliphatic isocyanates used in polyurethane adhesives include ... 

Resistant coatings High build solventless Range of colours Corrosion resistance Chemical resistance Excellent adhesion Potable water tanks Food industry Internal pipelining, etc. 

The polyurethane derivatives used in solventless coatings and adhesives systems form a relatively small part of the market. There were about 50 million pounds sales in 1979, however, the solventless segment can be expected to grow at more than the 10fa rate expected for all polyurethane coatings adhesives. 

We have described the current state of the industry market in solventless polyurethane coatings and adhesives. There is a wide variety of specialty materials available, all selling for widely different prices and consisting of a wide variety of chemical compositions. 

ATRP is an excellent method for the preparation of functional polymers. Polymers with molecular weights up to M =100,()00 can be obtained with narrow molecular weight distribution. Many functionalized styrenes, acrylates and other functional monomers were successfully polyineiized using a wide range of functional initiators or macroinitiators. Furthermore chain-end halogens can be displaced. Because of all these possibilities, ATRP can find applications in solventless coatings, adhesives, lubricants, surfactants and additives. 

For bonding molded parts of polycarbonate to other plastics, glass, wood, aluminum, brass, steel, and other materials, a wide variety of adhesives can be used. Generally, the best results are obtained with solventless materials, such as epoxies and urethanes. 

Water-based epoxy primers are ideal for damp porous substrates, as such primers will penetrate to an adequate depth to ensure good adhesion and produce a sound surface for bonding. Emulsifiable resins and hardeners are available, and the better systems deactivate the emulsifier system during cure to ensure that the cured system is not unduly water sensitive (Section VI.A). Solventless epoxy primers are used for bonding new concrete to existing concrete. Polyamide hardeners are preferred because of their ability to cure satisfactorily in the presence of water. Accelerators and diluents may be added, but fillers are generally omitted. The primer is applied to the existing concrete, and the fresh concrete cast before the resin has set (Section VI.B). 

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