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Migration ‘improvement

Migration improvement through improved materials and packaging design... [Pg.268]

Migration improvement (that is, a decrease in chemical migration from... [Pg.268]

The first organometallic [l,2]-migration was reported in 1929 by Karl Ziegler and CroPmann, When an ethereal solution of 1,1,3-triphenylindene is shaken with finely cut sodium for 8 days, a transient hydrocarbon/metal 1 2 adduct 322 forms. Instantaneous phenyl migration improves the resonance stabilization, and subsequent elimination of sodium hydride produces an optimally delocalized indenylsodium species 323 (Scheme 1-252). After hydrolysis, 1,2,3- triphenylindene is isolated. [Pg.162]

Uses Processing aid for rubber compounding inc. mixing speed while improving dispersion allows use of higher levels of plasticizers while reducing migration improves flow under mechanical pressure reduces swell and improves dimensional stability better release improves ozone/oil resist. [Pg.68]

Raw Materials. PVC is inherently a hard and brittle material and very sensitive to heat it thus must be modified with a variety of plasticizers, stabilizers, and other processing aids to form heat-stable flexible or semiflexible products or with lesser amounts of these processing aids for the manufacture of rigid products (see Vinyl polymers, vinyl chloride polymers). Plasticizer levels used to produce the desired softness and flexibihty in a finished product vary between 25 parts per hundred (pph) parts of PVC for flooring products to about 80—100 pph for apparel products (245). Numerous plasticizers (qv) are commercially available for PVC, although dioctyl phthalate (DOP) is by far the most widely used in industrial appHcations due to its excellent properties and low cost. For example, phosphates provide improved flame resistance, adipate esters enhance low temperature flexibihty, polymeric plasticizers such as glycol adipates and azelates improve the migration resistance, and phthalate esters provide compatibiUty and flexibihty (245). [Pg.420]

Another important pigment in this class is Pigment Red 170 [6985-95-17, which provides medium shades of red, and when particle-grown produces an opaque modification which shows improved migration resistance and lightfastness. Like some other Naphthol AS pigments it shows the phenomenon of polymorphism. [Pg.29]

Lubricants. Lubricants are used to improve the melt flow, screw feeding, and mold release of nylons. Long-chain acids, esters, and amides are used together with metal salts, eg, metal stearates. Improved melt flow is mainly a function of molecular weight reduction during mol ding. Mold release is improved by waxes of limited compatibiHty with nylon, which migrate to and lubricate the mold surface. [Pg.274]

See other pages where Migration ‘improvement is mentioned: [Pg.28]    [Pg.274]    [Pg.485]    [Pg.28]    [Pg.397]    [Pg.345]    [Pg.478]    [Pg.68]    [Pg.28]    [Pg.274]    [Pg.485]    [Pg.28]    [Pg.397]    [Pg.345]    [Pg.478]    [Pg.68]    [Pg.23]    [Pg.1349]    [Pg.2771]    [Pg.401]    [Pg.401]    [Pg.402]    [Pg.33]    [Pg.477]    [Pg.378]    [Pg.384]    [Pg.42]    [Pg.418]    [Pg.9]    [Pg.459]    [Pg.515]    [Pg.122]    [Pg.122]    [Pg.181]    [Pg.312]    [Pg.300]    [Pg.41]    [Pg.504]    [Pg.165]    [Pg.351]    [Pg.294]    [Pg.577]    [Pg.577]    [Pg.219]    [Pg.458]    [Pg.478]    [Pg.353]    [Pg.355]    [Pg.356]   


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