Polyesters bonding, adhesive

CAS 7128-64-5 EINECS/ELINCS 230-426-4 Uses Fluorescent whitener, optical brightener for thermoplastics (PVC, PE, PP, cellulose acetate, PS, PC, acrylics, polyolefins, PU, linear polyester, polyamides), adhesives, coatings, printing inks (for security bonds, bank notes), dyes, textiles (syn. fibers incl. PVC and acetate), molded articles, films, sheets, syn. leather, waxes, fats, and oils tracer in clear coatings... 

Uses Catalyst accelerator for unsat. polyester resins adhesion promoter for rubber-steel bonding whitener catalyst drier in paints, food-con-tact coatings... 

Yu. S. Lipatov, R. A. Veselovskii, and Yu. K. Znachkov, Characteristics of the Properties of Adhesives Based on Self-Penetrating Polymer Networks, Dokl. Akad. Nauk SSSR 238(1), 174 (1978). PU/Polyester IPN adhesives. Bonding strength. 

A blue pigmented polyester based bonding adhesive containing micospheres of plastic - a so-called syntatic... 

A white pigmented, polyester based bonding adhesive containing microspheres of plastic and specifically designed for use with balsa cores. 

The probability of a major role of the polyester group in reaction with dip chemicals during cure is quite low. The polyurethane-polyester bond is pictured primarily as a physical interaction rather than a chemical one. Iyengar" reported that the polyurethane from methylene-few(4-phenyl isocyanate) and the epoxide have a cohesive energy density of 10.5. Polyethylene terephthalate has a cohesive energy density of 10.3. The compatibility between these two networks would be quite high and the probability exists for adhesion by the diffusion theory of Voyutskii. ... 

In extmsion coating a polymer is extmded from a slot die into the nip of two roUs where it is bonded to a substrate under pressure (Fig. 6). A corona discharge may be appUed to the substrate just prior to the nip to enhance adhesion. Polyethylene or ionomer are the most common resins used in extmsion coatings. They provide improved moisture barrier (on paper), or sealabUity (on foU, polypropylene, or polyester). When a second substrate is introduced to the nip, laminated stmctures may be produced. 

Bonding. Surface treatment, such as chemical etch, corona, or flame treatments, is required for adhesive bonding of Tefzel. Polyester and epoxy compounds are suitable adhesives. 

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). 

Rubber. The mbber industry consumes finely ground metallic selenium and Selenac (selenium diethyl dithiocarbamate, R. T. Vanderbilt). Both are used with natural mbber and styrene—butadiene mbber (SBR) to increase the rate of vulcanization and improve the aging and mechanical properties of sulfudess and low sulfur stocks. Selenac is also used as an accelerator in butyl mbber and as an activator for other types of accelerators, eg, thiazoles (see Rubber chemicals). Selenium compounds are useflil as antioxidants (qv), uv stabilizers, (qv), bonding agents, carbon black activators, and polymerization additives. Selenac improves the adhesion of polyester fibers to mbber. 

Adhesion. Commercially available 1- or 2-coat adhesive systems produce mbber failure in bonds between ethylene—acryflc elastomer and metal (14). Adhesion to nylon, polyester, or aramid fiber cord or fabric is greatest when the cord or fabric have been treated with carboxylated nitrile mbber latex. 

SBR, polycarbonates, etc., can often be achieved by choosing a polyol backbone that is similar in polarity to the substrate to be bonded. For example, polyethers often work well for obtaining adhesion to these medium polarity plastics, whereas polyesters usually work better for polar substrates, such as glass and metal. 

The crystallization kinetics defines the open time of the bond. For automated industrial processes, a fast crystallizing backbone, such as hexamethylene adipate, is often highly desirable. Once the bond line cools, crystallization can occur in less than 2 min. Thus, minimal time is needed to hold or clamp the substrates until fixturing strength is achieved. For specialty or non-automated processes, the PUD backbone might be based on a polyester polyol with slow crystallization kinetics. This gives the adhesive end user additional open time, after the adhesive has been activated, in which to make the bond. The crystallization kinetics for various waterborne dispersions were determined by Dormish and Witowski by following the Shore hardness. Open times of up to 40 min were measured [60]. 

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