Zirconium carboxylates

Zirconium propionate is a polymeric zirconium carboxylate its structure is illustrated in Fig. 10. Use of zirconium propionate markedly increases the adhesion of an ink applied to treated polypropylene film. Figure 11 compares zirconium propionate with titanium acetylacetonate, which is commonly regarded as the industry standard. The standard test method used in the ink industry is the so-called tape test . Sticky tape is placed on the printed film and pressure is applied by the operator s thumb. The tape is then pulled off, by hand, and the amount of ink removed is visually assessed. Although extremely crude, it can be, and is, used for control in the ink industry. 

Alpha-Sablin [Alpha Sabic Linde] (also written a-Sablin) A process for making linear C4-C10 olefins from ethylene. Catalyzed by zirconium carboxylates with aluminum alkyls, used in a bubble column reactor. Developed between 1994 and 2001 by Sabic and Linde. The first commercial plant was completed in Al-Jubail, Saudi Arabia, in 2009. A second plant is expected to come on stream in Nizhnekamsk, Russia, in 2014. 

Garboxylates. Zirconium hydroxy carboxylates of the generic type... 

Zirconium oxalates exist as compounds, double compounds, and mixed oxalato complexes (165,195,225—226). When the carboxylate ligand is a longer alkyl chain, the materials often are called zirconium soaps. 

Alkyds. Alkyd resins (qv) are polyesters formed by the reaction of polybasic acids, unsaturated fatty acids, and polyhydric alcohols (see Alcohols, POLYHYDRic). Modified alkyds are made when epoxy, sUicone, urethane, or vinyl resins take part in this reaction. The resins cross-link by reaction with oxygen in the air, and carboxylate salts of cobalt, chromium, manganese, zinc, or zirconium are included in the formulation to catalyze drying. 

The third general classification of solution synthesis approaches used for inorganic electronic thin film fabrication is referred to as metallo-organic decomposition, or MOD for short.23-29,37,38,85 Historically long-chain carboxylate compounds, such as lead 2-ethylhexanoate, zirconium neodecanoate, and titanium di-methoxy di-neodecanoate have been used.23-29,85 Both commercially available precursors and in-house synthesized starting reagents have been used. 

Crystals of complex 112 suitable for an X-ray structure determination were obtained on cooling a solution in pentane to — 30 °C. The structure determined is shown in Fig. 7.9. The most remarkable structural feature of 112 is that the gallium center is connected to the zirconium through two different c-carboxylic bridges. One of them contains the cyclo-C6Hg system, which is t]1-bonded to gallium and r 2-coordinated to zirconium. It is noteworthy that carbon atom C-2 is planar tetracoordinate. It is connected to four neighboring atoms in the c-plane, specifically to carbon atoms C-l and C-3 and to both metal centers [175]. 

Zirconium and hafnium tetraalkoxides are highly reactive compounds. They react with water, alcohols, silanols, hydrogen halides, acetyl halides, certain Lewis bases, aryl isocyanates and other metal alkoxides. With chelating hydroxylic compounds HL, such as j8-diketones, carboxylic acids and Schiff bases, they give complexes of the type ML (OR)4 these reactions are discussed in the sections dealing with the chelating ligand. 

In the case of organic derivatives such as zirconium acetate, direct bonding of the carboxyiate to the zirconium is found. Similar structures are also found in solvent-soluble, water-insoluble carboxylates such as zirconium propionate. Zirconium alkoxide derivatives tend to be monomeric in solvent-based systems but hydrolyse rapidly with ambient water to give polymeric species. 

These zirconium polymers tend to display two basic reactions. First, there is the reaction with carboxyl groups, where strong covalent bonds are formed (Fig. 3) second, they can undergo hydrogen bonding interactions with hydroxyl groups, as shown in Fig. 4. 

Figure 3. Interaction between zirconium polymers and carboxyl groups.

It is believed that zirconium functions by reacting with carboxyl groups on the surface of the treated plastic and further reacting with suitable functional groups on the resins used as the binders in the ink. This is shown in Fig. 6. 

Evidence for this is rather sparse, but recent XPS work on the interaction of zirconium compounds with polymer particles [5] and corona discharge-treated polypropylene [6] supports the view that zirconium will react with the surface carboxyl functionality. Interestingly, titanium complexes are believed [6] to prefer to bond to surface hydroxyl groups. 

A recent patent by Thomason [15] has revealed that ammonium zirconium carbonate when applied to a substrate such as glass, aluminium, or polypropylene can improve the adhesion of microsphere polymer-based adhesives. It is proposed that the zirconium after reacting with the substrate surface reacts with carboxyl groups at the surface of the polymer microspheres. 

Brewis [5] has reported that tack reduction observed with various adhesives after treatment with aqueous zirconium compounds is due to zirconium reacting with carboxyl groups on the surface of the polymer particles. This has been confirmed by XPS surface analysis, which showed that the zirconium compounds reacted with carboxyl groups and that the effectiveness of the zirconium compounds was directly related to the carboxyl concentration. 

Zirconium acetylacetonate can react in a similar way and as noted previously, surface analysis of zirconium acetylacetonate derivatives on corona-discharged polypropylene has shown bonding to the surface carboxyl groups [6]. 

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