Accelerator epoxy resin

Imidazole-4,5-dicarboxylic acids, coupling, 5, 403 decarboxylation, 5, 434 1-substituted synthesis, 5, 468 synthesis, 5, 362, 402, 484 Imidazole-4,5-dione, l-alkyl-2-phenyl-synthesis, 5, 129, 479 Imidazole-2,4-diones tautomerism, 5, 370 Imidazole-4,5-diones tautomerism, 5, 370 Imidazole-2,4-dithione, 5,5-diphenyl-tautomerism, 5, 370 Imidazole-2,4-dithiones tautomerism, 5, 370 Imidazolepropanol synthesis, 5, 486 Imidazoles accelerators epoxy resins, 1, 407... 

Brorson, S.-H. 1998a. The combination of high-accelerator epoxy resin and antigen retrieval to obtain more intense immunolabeling on epoxy sections than on LR-white sections for large proteins. Micron 29 89-95. 

Hosokawa, T. Matsushita, T. Hata, M. Encapsulated cross-linking agents or accelerators, epoxy resins containing the microcapsules, curing process of the resins, and cured products. JP 08337633, 1996. 

Uses Antioxidant in cosmetics, soaps produced from animal or vegetable oil hardener for decorative and protective powd. coatings vulcanization accelerator epoxy resin curing agent Manuf/Distrib. Aceto Aldrich Thomas Swan Trade Names Aradur 2844... 

The binder system of a plastic encapsulant consists of an epoxy resin, a hardener or curing agent, and an accelerating catalyst system. The conversion of epoxies from the Hquid (thermoplastic) state to tough, hard, thermoset soHds is accompHshed by the addition of chemically active compounds known as curing agents. Flame retardants (qv), usually in the form of halogens, are added to the epoxy resin backbone because epoxy resins are inherently flammable. 

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. 

Polyphenols or phenol-terminated resins are utilized to effect chemical cross-linking of epoxy resins with added catalysts or accelerators for the reaction (26). 

Epoxy (Anhydride-Cured) Epoxy resins may be crosslinked with various anhydrides by using a tertiary amine accelerator and heat. These cured polymers generally have good chemical resistance especially to acids. 

Mixing of propylene oxide and epoxy resin in a waste bottle led to an explosion, probably owing to the polymerisation of the oxide catalysed by the amine accelerator in the resin. 

P.Y.97 is also used to lend color to cast epoxy resins and to unsaturated polyester resins it considerably accelerates the hardening process in the latter (Sec. 1.8.3.7). 

Reactivity of Amine Accelerators with Anhydride-Epoxy Resin Systems ... 

The gluability of the lignin-epoxy resin adhesives was found to be improved by the addition of calcium carbonate (50% by weight) to the liquid resin. This must be attributed to the nature of the weak alkali in calcium carbonate as a cure accelerator, and to the reinforcement effect of fillers. Since wood surfaces are acidic, the addition of alkaline fillers effectively alters the pH of the glue line. 

The liquid polymer is converted to the rubbery state by reagents that react with mercaptan (-SH) and side groups of the polymer segments by oxidation, addition or condensation to effect sulfide (-S-S-) bond formation. The oxidation reactions are exothermic and accelerated by an alkaline environment. The most commonly employed oxidizing agents which are suitable for curing liquid polymers are cobalt or manganese or lead octoate, p-quinonedioxime and di- or tri-nitrobenzene. Epoxy resin also reacts with liquid polysulfide polymers by addition in the presence of an aliphatic or aromatic amine and polyamide activator as shown in Equation 5.8 ... 

Tertiary amines are used to accelerate both amine and anhydride cures of epoxy resins (B-67MI11501). Certain heterocyclic amines have been used for this purpose, including pyridine and piperidine. In the case of anhydride cures, the use of an amine catalyst not only accelerates the cure, but also improves the thermal stability of the cured resin. 

The catalytic effect has been explained in terms of the activation of the anhydride by interaction with the amine to give a zwitterionic intermediate (47 Scheme 10) (B-68MI11501). Imidazoles have also been suggested as accelerators for anhydride cures (68USP3394105). A review of the patent literature (B-77MI11502) shows that several heterocyclic compounds are of interest as curatives for epoxy resins. 

In general the amine-epoxy resin curing reactions show complex kinetics typified by an initial acceleration due to autocatalysis, while the later post-gelation stages may exhibit retardation as the mechanism becomes diffusion-controlled. However some workers 72 80) have found that over a limited range of conversion the kinetic data may be described by the simple models of Eq. (2-6) or (2-9). 

The cure kinetics of some epoxy resin powder coating composition were reported by Olcese et al.108). These were mixtures of BADGE resins with DICY and an epoxide-amine adduct or an imidazole as accelerator, together with TiOz and plasticisers. Data from DSC scans were analysed using Eq. (2-12) to obtain the apparent activation energy, E. Also Eq. (2-13) and (2-13 a) were used to obtain estimates of E and order... 

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