Caprolactam-blocked

Blocked isocyanates are also nsed as cross-linking agents for powder coatings. Becanse of its high melting point, caprolactam blocked, l-(isocyanatomethyl)-5-isocyanato-l,3,3-trimethyl-cyclohexane (IPDI) is commonly used. Especially suited for this application are isocyanurate trimers. Despite catalysis with DBTDL, caprolactam-blocked isocyanates require a cure temperature of 180-200 °C. To achieve a lower cure temperature of about 140 °C, ketoxime-blocked isocyanates are used.i°°... 

Coating powders for exterior use are mainly based on the SP-TGIC system. Of some importance is the SP-PUR system, i.e., the combination of hydroxy-functional polyester resins with caprolactam-blocked isocyanate adducts (primarily based on isophorone diisocyanate). The newly developed SP-HAA and SP-glycidyl estermix systems avoid the problems of TGIC as regards toxicology. Acrylic resins are of importance mainly in the United States (AY-PUR) and in Japan (AY-DDA). The AY-PUR system is used for automotive components and in domestic appliances. The PUR systems based on uretdione (a dimerization product of isocyanates) do not... 

Yin et al. (2009b) prepared blends of PA-6 with SEES which had been functionalized with s-caprolactam-blocked aUyl (3-isocyanate-4-tolyl) carbamate. 

Isonate 123P—E-caprolactam blocked Py4P/(Upjohn Company) Fig. 8.9. Examples of blocked isocyanates. 

Commercially available blocked isocyanates include Hylene MP or 4715 from Du Pont (now withdrawn), which is phenol-blocked MDI (Du Pont International S.A., Geneva, Switzerland) Mondur S, a phenol-blocked TDI adduct, Mondur SH, a cresol-blocked TDI trimer, and Experimental E-320-blocked isocyanate, a ketoxime-blocked tetraisocyanate, all from Mobay (Pittsburgh, Pennsylvania, USA) and Isonate 123P, which is s-caprolactam-blocked PAPI, from the Upjohn Company (Dow Chemical Europe, Horgen, Switzerland). These are shown in Fig. 8.9. Uniroyal also market a product. 

Rgure43 Polymerization of caprolactam-blocked rotaxanes 143 to 145 to form main-chain, side-chain, and network polyrotaxanes. 

Conunercially available blocked isocyanates have included Hylene MP from duPont (XXI) " which is phenol-blocked MDI Mon-dur S (XXII), a phenol-blocked TDI adduct Mondur SH (XXIII), a cresol-blocked TDI tiimer and Experimental E-320 blocked isocyanate (XXIV), a ketoxime-blocked tetraisocyanate, all from Mobay and Isonate 123P (XXV)" which is -caprolactam-blocked PAPI from the Upjohn Company. The Ashland Chemical Company has marketed a conuner-cial chemical class called aminimides which act as isocyanate precursors, eliminating the problem of by-product phenol from the use of phenol-blocked isocyanates.Their chemistry relevant to this use, is as follows ... 

Isonate 123P (Caprolactam—blocked PAPI), Bulletin CD 1217 (June 1971) Product Report (September 1, 1969), The Upjohn Co. Kalamazoo, Mich. 

Crosslinking agents were also commercially available materials and used as received. Bisphenol A -isopropylidenedi-phenol) was obtained from the Shell Chemical Company the cross-linking agent -methylenedianiline (MDA) was obtained from the Giba Products Company and a caprolactam blocked triisocyanate (Isenate 123 p) was obtained from the Upjohn Company. 

The chemical composition of the prepolymer also affects the tensile properties of the networks. Effects of incorporation of styrene in copolymers of 2-hydroxyethylmethacrylate with methylmethacrylate are illustrated in Fig. 1. A series of terpolymers containing 35 percent of 2-hydroxyethylmethacrylate 5 to 65 percent styrene and the balance methylmethacrylate were crosslinked with a caprolactam blocked triisocyanate. The elongation-to-... 

Mathias L J, Moore D R and Smith A S (1987) Polymerization of N-(p-amino-benzoyl)caprolactam Block and alternating copolymers of aromatic and ahphatic polyamides, J Polym Sci A Polym Chem Ed 25 2699-2709. 

Roda, J. (2000) Copolymers of Poly(e-caprolactam)-block-(butadiene-containing elastomers), in Block Copolymers (eds F.J. 

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