Adhesive, accelerators

TABLE 12.8 Properties of DGEBA-Dicyandiamide Cured Adhesive Accelerated with Substituted Ureas11... 

The condensation products of amines and aldehydes have often been used as the reduc-tant. The most common commercial example is that arising from aniline and butyraldehyde for which the active ingredient has been identified as 3,5-diethyl-1,2-dihydro-l-phenyl-2-propyl-pyridine (DHP). A high purity grade, >85% active, has become available in recent years (Reilly Industries, PDHP Adhesive Accelerator Vanderbilt, Vanax 808 HP). 

Environmental Toxic to fish nontoxic to bees Precaution Combustible can form explosive mixts. with air > 89 C Hazardous Decomp. Prods. CO, CO2, SO, CS2 Uses Vulcanizing agent, accelerator for rubber preservative for natural rubber latex fungicide insecticide seed protectant/disinfectant animal repellent antioxidant for polyolefins lube oil additive in food-pkg. adhesives accelerator for food-contact rubber articles for repeated use antiseptic antibacterial, antifungal for topical pharmaceuticals Regulatory FDA 21CFR 175.105,177.2600 SARA reportable Manuf./Distrib. Aldrich Atofina Agri Complex Ouimica SA FMC Foret ... 

Uses Vulcanization accelerator for NR, SBR, latex, latex foam, dipped goods, fabric coatings preservative for natural rubber latex heat stabilizer for polyethylene activator for thiazoles in food-pkg. adhesives accelerator in food-contact rubber articles for repeated use Regulatory FDA 21 CFR 175.105,177.2600 Manuf/Distrib. Akzo Nobel Complex Quimica SA Micro S.A. de C.V. ... 

Uses Vulcanizing agent, accelerator for rubber preservative for natural rubber latex fungicide insecticide seed protectant/disinfectant animal repellent antioxidant for polyolefins lube oil additive in food-pkg. adhesives accelerator for food-contact rubber articles for repeated use antiseptic antibacterial, antifungal for topical pharmaceuticals... 

Adhesion Accelerator Accelerator dosage Sulphur level Cure... 

Uses Humectant, plasticizer, lubricant, antistatic agent for adhesives accelerator for nat., syn. rubber vehicle, binder, lubricant in metal polishing paste plasticizer, temporary binder for ceramics lubricant, binder, vehicle, thixotropic agent for seri-graphy carrier for llq. non-aq. detergents consistency agent for enzymes, toilet bowl cleaners... 

The routine compositional and functional testing done on the adhesives includes gas chromatographic testing for purity, potentiometric titrations for acid stabilizer concentrations, accelerated thermal stabiUty tests for shelf life, fixture time cure speed tests, and assorted ASTM tests for tensile shear strengths, peel and impact strengths, and hot strengths. 

Natural-mbber-based pressure-sensitive adhesives can be cured by standard mbber curatives, eg, sulfur plus an accelerator (see Rubber, natural) ... 

Formulation. Polysulftde-based sealants are formulated with appropriate ingredients to obtain the desired properties for a particular appHcation. A typical formulation contains Hquid polysulftde polymer, curing agent, cure accelerators (bases) or retarders (acids), fillers, plasticizers, thixotropes, and adhesion promoters. 

High purity 4-dodecylphenol is used to produce specialty surfactants by its reaction with ethylene oxide. The low color of high purity 4-dodecylphenol is important in this appHcation from a standpoint of aesthetics. 4-Dodecylphenol is also used to produce phenoHc resins which are used in adhesive appHcations and printing inks. 4-Dodecylphenol is also used as an epoxy curing catalyst where the addition of 4-dodecylphenol accelerates curing of the epoxy resin to a hard, nontacky soHd. 

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. 

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