Zinc type

A process based on saponification of ethylene—acrylate ester copolymers has been practiced commercially in Japan (29). The saponification naturally produces fully neutralized polymer, and it is then necessary to acidify in order to obtain a pardy neutralized, melt-processible product. Technology is described to convert the sodium ionomer produced by this process to the zinc type by soaking pellets in zinc acetate solution, followed by drying (29). 

Cleaners containing silicate can cause problems. They should not be used prior to an alkaline process on aluminium, owing to the formation on the surface of alkali-insoluble aluminium silicate. Silicated cleaners can also cause problems before some surface-sensitive zinc phosphating solutions, especially the more modern low-zinc type. 

Some of the paint types belonging to classes such as alkyds, coaltar epoxies, epoxy, heat-resistant, inorganic zinc types, polyurethanes, water-borne coatings as described by Sigma coatings are given in Table 1.29. 

Low density polyethylene film (LDPE) (5-1 x 10 mm thick) obtained from Dow Chemical Co., Surlyn S-1601 (sodium tjjpe 5-1 x 10 mm thick) and Surlyn S-1625 (zinc type 7.6 x 10 mm thick) obtained from DuPont. The samples were cut into strips, 2.5 cm x 12.7 cm, and immersed into juice (7 samples per 250 ml bottle) which had been filled into amber glass bottles and closed with a screw cap. 

Absorption of d-limonene by the different sealant films during storage at 24°C, 49 RH is shown in Table 3- Within 3 days storage, all of the films had rapidly absorbed d-limonene. After 3 days, the rate of absorption in LDPE and Surlyn (sodium type) decreased, while Surlyn (zinc type) had reached saturation. 12 and 18 days were required to reach saturation for Surlyn (sodium type) and LDPE respectively. Thg amount of d-limonene absorbed at equilibrium was 6.4 mg/100 cm for Surlyn (zinc type). The carboxy and zinc groups in the Surlyn probably alter the lipophilic character of the polymer, but do not prevent absorption of flavor components. 

S-1601 Surlyn, sodium type S-1652 Surlyn, zinc type... 

The oxygen permeability constants for LDPE, Surlyn (sodium type) and Surlyn zinc type) (non immersed) were 88.9. 111.8, and 116.8 (cc.mm/m. day.atm), respectively. After d-limonene was absorbed by the films, the permeability constants increased to 406.4, 279-4 and 185-4 respectively. Mohney et al. (20) and Baner (21) also found that absorption of organic flavor constituents by films increased the permeability of the films to the flavor constituents. 

Zinc-type amalgams with Zn, Cd, Pb, Tl, Sn, and Bi are easily amalgamated and readily soluble in mercury. They exhibit the same potential as the pure metal and are suited for phase separation. 

Not all countries will abandon lead within the same time schedule as Europe. Almost half of China s stabiliser consumption was lead-based in 2002, and this is not expected to change very rapidly. Chemson, the leading European stabiliser manufacturer, entered into partnership with Dalian Shide, the biggest PVC company in China, in 2001 to build a plant that produces both lead and calcium-zinc stabilisers. However, China is importing some tin and calcium-zinc types. 

A fall in consumption of heat stabilisers in Japan has been caused both by a switch from lead and by a decline in PVC sales. In 1999 heat stabiliser shipments were 70,000 t/y, but they fell to 53,466 tonnes in 2002 and 51,700 tonnes in 2003, according to the Japan Inorganic Chemical Industry Association. Lead accounted for only half the Japanese heat stabiliser usage by 2002 and its market share continues to fall, while demand for calcium-zinc types is growing. A breakdown of shipments by type is given in Table 6.9. (The total for 2002 is very slightly different from the one just cited.)... 

Location and water Type of zinc Type of test Years Agitation (p,m/year) Remarks... 

The stabilizers are used to perform specific functions. Thus, there are antioxidants, viz. sterically hindered phenols [e.g., pentaerythritol ester] and/or sterically hindered amines (hydro)-peroxide decomposers, viz. phosphite [e.g., tris(2,4-di-tert-butyl phenyl)-phosphite] radical scavengers such as thio-derivatives heat stabilizers [e.g., calcium-zinc type for PVCj light stabilizers and UV blockers [e.g. aluminum flakes or carbon black] for outdoor storage and applications, etc. 

Mechanically rechargeable zinc-air batteries can give twice the energy density of carbon-zinc types of cell currently in production. Energy densities up to 220 Wh/kg are well within the capability of this system, compared with the 55-77Wh/kg obtainable from carbon-zinc types of primary cell. 

Precaution Eye protection rec. wear protective gloves when handling molten product, respirator if dust Is present avoid all contact Incompat. with strong oxidizers Storage Store In cool, dry place In stainless steel, zinc-type spray-on linings, flaked polyester away from sources of Ignition CO-1898 (Procter Gamble]... 

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