Agents for Epoxy Resins

1) Primary and secondary aliphatic polyamines These are low viscosity and low cost materials. In general, linear and branched primary and secondary aliphatic 

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In addition, boron trifluoride and some of its adducts have widespread appflcation as curing agents for epoxy resins (qv), and in preparing alcohol-soluble phenoflc resins (qv) (41). 

Phenylenediamines are used in a variety of other appHcations, such as corrosion inhibitors, cross-linking agents for epoxy resins, toners for electrostatic image development (35), and to improve wrinkle resistance of cellulose acetate fibers (36). 

Process Raw Material. Industrial solvents are raw materials in some production processes. Eor example, only a small proportion of acetone is used as a solvent, most is used in producing methyl methacrylate and bisphenol A. Alcohols are used in the manufacture of esters and glycol ethers. Diethylenetriamine is also used in the manufacture of curing agents for epoxy resins. Traditionally, chlorinated hydrocarbon solvents have been the starting materials for duorinated hydrocarbon production. 

Flexibilized epoxy resins are important structural adhesives [69]. Liquid functionally terminated nitrile rubbers are excellent flexibilizing agents for epoxy resins. This liquid nitrile rubber can be reacted into the epoxy matrix if it contains carboxylated terminated functionalities or by adding an amine terminated rubber. The main effects produced by addition of liquid nitrile rubber in epoxy formulations is the increase in T-peel strength and in low-temperature lap shear strength, without reducing the elevated temperature lap shear. 

WASTE PET - DERIVED SUBSTANCES AS CROSSLINKING AGENTS FOR EPOXY RESINS... 

Cyclic acid anhydrides such as maleic, dodecylsuccinic, hexahydrophthalic, phthalic, phyromellitic, etc. are widely employed as curing agents for epoxy resins. They form esters with epoxy resins. These resins have better thermal stability and good electrical insulation and chemical resistance expect to alkalis. 

The study relates to new classes of thermosetting oligomers based on N-cyanourea-terminated resins, which are useful as a monomer, a thermosetting resin, and a cross-linking agent for epoxy resins. 

Lin, S. C., "Novel Cross-linking System - N-Cyanourea and Its Adducts as Latent Curing Agent for Epoxy Resins," U.S. Patent 4 379 728, 1983. 

Uses. Production of methylene diphenyl diisocyanate (MDI), which is used to produce polyurethanes hardening agent for epoxy resins, anticorrosive materials, printed circuit parts, dyestuff intermediates, filament-wound pipe, and wire coatings... 

Nylons 6/6 and 6 comprise more than 90% of the polyamide market. The two have similar properties but nylon 6 has a lower Tm (223°C). Small amounts of nylons 6/9, 6/10, 6/12, 11, 12, 12/12, and 4/6 are produced as specialty materials. Those with more methylene groups than nylons 6/6 and 6 have better moisture resistance, dimensional stability, and electrical properties, but the degree of crystallinity, Tm, and mechanical properties are lower. Specialty nylons made from dimerized fatty acids find applications as hot-melt adhesives, crosslinking agents for epoxy resins, and thermographic inks. 

The fluffy product is extremely finely divided (particle size typically 7-40 nm, powder density 0.03-0.06 g cm-3) but nonporous (surface area ca. 200-400 m2 g-1). Like fused silica, silica fume is amorphous, and this, together with the small particle size, gives it relatively high solubility. It is used as a thixotropic thickening agent for epoxy resins, in special high strength... 

Heat resistant resin compositions based on BMI/aminophenol-Epoxy blends are achieved by reacting a BMI/p-aminophenol 1 1 adduct with epoxy resin (62). Both the secondary amine and phenol functionality may react with the epoxy resin and subsequently cure through an imidazole catalyst. Imidazole catalysts promote both the epoxy/phenol reaction and the anionic maleimide crosslinking. The formation of a 1 2 BMI/aminophenol adduct, as in Fig. 20, is claimed in a patent (63). The hydroxy terminated BMI/aminophenol adduct is an advantageous curing agent for epoxy resins when high temperature performance is desired. 

Tertiary amines (TA) may be utilized both as independent curing agents for epoxy resins and as catalysts in the reaction of epoxy compounds with alcohols, phenols, carboxylic adds and their anhydrides i - 5. Besides, the three-... 

The molecular structure of epoxy/metal interphases in the presence of an amino coupling agent was studied by Boerio and co-workers [28] by IR and by XPS. The formation of amide and imide groups in the interphase provided evidence of chemical reaction between the silane primer and the curing agent for epoxy resin. 

They are also used for vulcanization of organosilicon cauchucs, solidifying agents for epoxy resins, additives to pigments, and so on. [715]. 

Kiyono, S. 1997. Heat resistant epoxy resin composition having excellent stability at normal temperature and curing agent for epoxy resin. U.S. Patent 5,610,209. 

Amines are one of the most important curing agents for epoxy resins. They provide fast cures with a relatively high crosslink density. Unmodified amine cured epoxy resins are generally too brittle for adhesive applications, and so there are many derivatives that have been developed. More information on amine curing agents can be found in Chap. 5. 

Aromatic amines are widely used as curing agents for epoxy resins. However, they are not used as widely in adhesive formulations as they are in composites, molding compounds, and castings. They offer cured epoxy structures with good heat and acid resistance. 

As a family of curing agents for epoxy resins, the amidoamines are lower in viscosity than the polyamides. They exhibit very good adhesive properties due to their chemical structure and easy penetration. Amidoamine cured epoxy adhesives have shown very good properties on concrete and other porous substrates. They cure extremely well under humid conditions. In fact amidoamine cured epoxy formulations have been used to cure underwater in certain applications. A typical general-purpose room temperature curing epoxy-amidoamine system is described in Table 11.7. This adhesive is used as a general-purpose metal-to-metal adhesive and body solder in the automotive industry. 

Thermoset plastics have also been pyrolysed with a view to obtain chemicals for recycling into the petrochemical industry. Pyrolysis of a polyester/styrene copolymer resin composite produced a wax which consisted of 96 wt% of phthalic anhydride and an oil composed of 26 wt% styrene. The phthalic anhydride is used as a modifying agent in polyester resin manufacture and can also be used as a cross-linking agent for epoxy resins. Phthalic anhydride is a characteristic early degradation product of unsaturated thermoset polyesters derived from orf/io-phthalic acid [56, 57]. Kaminsky et al. [9] investigated the pyrolysis of polyester at 768°C in a fiuidized-bed reactor and reported 18.1 wt% conversion to benzene. 

Technical Bulletin, The Curezol Series Imidazole Group Curing Agents for Epoxy Resins , Shikoku Fine Chemical Corp., Okura and Co. Inc., New York, NY, U.S.A. 

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