Zinc complexes maleic acid

Poly(vinyl alcohol) is utilized as a component of starch-based adhesives.11121114 Other patents report the use of partially oxidized starch,1115 dextrins,1116 dextrins and urea,1117 borax,1118 boric acid,1119 and vinyl methyl ether-maleic acid copolymers.1120 Other patents indicate the use of poly (vinyl alcohol) with partially hydrolyzed poly(vinyl acetate),1121 nonhy-drolyzed poly(vinyl acetate),1122 and poly(vinyl chloride).1123 A few patents have reported such poly acrylic additives as poly (acrylic acid)1124 and its salts,1125 poly(acrylamide),1126 1127 A-methylacrylamide or poly(A-acryl-amide),1128 and polyethyleneimine.1129 Polystyrene has also been used,1130 as well as more complex copolymers such as a maleic acid monobutyl ester-methyl vinyl ether copolymer, together with dextrin and polyacrylamide),1131 carboxylated ethyl acrylate-styrene zinc salt copolymer,1132 ethylene-methyl acrylate-vinyl acetate copolymer,1133 vinyl acetate-vinyl pyr-rolidone copolymer,1134 and ethylene-vinyl acetate copolymer.1135 Some adhesives are compounded with SBR latex1136 1138 and phenol-formaldehyde resins.1139... 

The colorless zinc compound, Zn(CisH6)2, which sublimes at 160° under partial decomposition, is obtained in small yield from zinc chloride and cyclopentadienyl sodium in diethyl ether however, the less stable cadmium compound decomposes, with separation of cadmium, under these conditions (55). The mercury compound, Hg(CsH5)2, is produced in 20% yield by the action of the sodium derivative on mercuric chloride in tetrahydrofuran (215). The action of cyclopentadiene on the complex K2(HgI ) in aqueous alkaline solution results in the precipitation of a mixture of CsHsHgl and Hg(CsH6)2, from which the latter compound may be obtained in good yield by extraction with a mixture of tetrahydrofuran and petroleum ether (62). It forms pale yellow crystals which begin to decompose at about 60° and which melt at 83-85°. The compound is readily soluble in most solvents it decomposes slowly even when kept in the dark at room temperature it is insoluble in water and reacts with neither water nor bases. On the other hand, decomposition occurs in dilute hydrochloric acid. It converts ferric chloride to ferrocene quantitatively, and it yields an adduct with maleic anhydride (215). 

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