Polypropylene pigments

Stabilization of Pigmented Polypropylene With Zinc Salts... 

That the composition of the resin has a significant influence upon the temperature gradient of the aging rate was also shown in a study of pigmented polypropylene by Fitton and Taylor (3). Their data show... 

Two small calibration sets were prepared with HALS 1 and UVA 1 in a blue pigmented polypropylene concentrate. The compositions are listed below (Table 5). 

Figure 2. The effect of pigment content on the degree of crystallinity of pigmented polypropylene.

Fabrics used in the automotive industry must meet exceptionally high requirements and be subjected to nonstandard tests that simulate the high-temperature and humidity conditions of light exposure [7]. Dyed fibers cannot meet these accelerated exposure specifications, which are met by specially stabilized, pigmented polypropylene fibers. The outdoor use of polypropylene fibers is expected to grow because of improved stabilizers. It has permitted grass-substitute products to be manufactured in a variety of forms. Many of them resemble carpets, which, until 1980, were used only indoors. 

Figure 18.54 Correlation between direct sunlight exposures in UK and at Curasao for pigmented polypropylene without UV stabiliser. [Source Author s own files)...

Figure 18.56 Effect of UV stabiliser on the lives of pigmented polypropylene.

In immersion tests, Ti02-pigmented polypropylene exhibits significantly lower change in mass than polypropylene with ZnS content. A pigment mixture of TiOj and ZnS in a 1 1 ratio has proven unfavorable in this respect. 

Figure 5.286 Optical change in pigmented polypropylenes after 14 days exposure to HNO at 60 °C top metal oxide pigments (TiOJ, bottom salts of weak acids (ZnS) [831]...

Kurzbock, M., Wallner, G.M., Lang, R.W. Black pigmented polypropylene materials for solar absorbers. Energy Procedia 30, 438-445 (2012)... 

The pigments are used primarily in plastics, including polypropylene fibers, because of very good bleed resistance, heat stabiUty, and lightfastness. The reds also find use in printing inks, primarily for high quaUty products. 

Pigment Yellow 141 [76168-75-7] is derived from reaction of l-aminoanthraquiaone with l-phenyl-3,5-dichloto-2,4,6-triaziQe. It is a reddish shade yellow pigment used primarily ia certain plastics and ia polyester and polypropylene fibers. 

Polypropylene [9003-07-0] is made by the polymerization of propylene gas. Polypropylene (qv) sutures are available in clear (undyed) or blue (melt-pigmented with [phthalocyaninato(2-)] copper). Monofilament polypropylene sutures are sold under the trade names Deklene, Prolene, Surgdene, and Surgipro. 

Polypropylene can be fabricated by almost any process used for plastics (see Plastics processing). The extmsion of pipe and injection mol ding of fittings present no unusual problem. However, there is no way to bond the fittings to the pipe except by remelting the polymer, which is impractical on most constmction sites. The resin can be reinforced by glass fibers, mineral fillers, or other types of fillers and can be pigmented readily. 

Tile is based mainly on vinyl chloride and vinyl acetate copolymers. Some polypropylene tile systems have recendy been iatroduced. A petroleum resia is usually employed as an extender and processiag aid conventional vinyl plasticizers and stabilizers also are iacorporated. Reinforcing fibers and limestone constitute the remainder of the tile composition the fibers contribute hot strength for processiag and dimensional stabiHty ia the finished tile, limestone suppHes bulk at an economical cost. Stable pigments are also iacorporated. Siace tile is iastalled oa and below grade level, it is important that the finished product be resistant to the effects of moisture and alkaH. 

Monoazo Pigments. In combination with other groups, the a2o linkage, —N=N—, imparts color to many dyes and pigments (see Azo Dyes). The simplest of these, ie, the Hansa yellows, toluidine reds, and naphthol reds, do not have the lightfastness and heat stabiUty required for plastics. Permanent YeUow FGL and Permanent Red 2B are stable enough for vinyls, polyethylene, polypropylene, and ceUulosics (11). Permanent Red 2B is available as the calcium, barium, or manganese salt. 

DlsaZO Pigments. The diaiylide yeUows and oranges also known as benzidines are derivatives of benzidine coupled to two moles of substituted acetoacetanilide. Benzidine Yellows AAMX, AAOT, AAOA, and HR (PY 13, 14, 17, and 83) ate examples (Fig. 1). Yellows AAMX and AAOT are used in flexible vinyls. AAOA also colors polyethylene and polypropylene. These three differ only slightly in shade. Benzidine YeUow HR is redder. 

These pigments are recommended for most plastic systems because of their excellent stabiUty to chemicals, bleeding, and light. They are widely used in vinyls, polyethylene, polypropylene, and ceUulosic plastics. The Colourindex classes are Hsted as PR 123, 149, 179, and 190. 

In general the selection of pigments for polypropylene follows the same considerations as for polyethylene. Because of the higher processing temperatures and the lesser resistance to oxidation, selection does, however, require rather more care. 

Polypropylene (PP) is a crystalline polymer suitable for low-stress applications up to 225°F (105°C). For piping applications this polymer is not recommended above 212°F (100°C). Polypropylene is shielded, pigmented, or stabilized to protect it from uv light. Polypropylene is often a combination of polyethylene and polypropylene which enhances the ductility of the polymer. 

Small-angle X-ray scattering (SAXS) data have made it possible to deduce the localisation of organic additives (pigments) in the bulk of isotactic polypropylene (iPP) [344]. This work has confirmed that the additives are located in the amorphous phase, in spite of their crucial influence on the formation of the crystalline phase of iPP. SAXS has also been used to study the 3D structure of different carbon-black aggregates, and silica-filled SBR rubber compounds [345]. 

One outlet for polypropylene, polyethylene, and polyvinyl chloride waste is plastic lumber. These materials, often containing more than one polymer and a wide variety of additives, provide superior weather resistance in humid environments when compared to natural wood. To manufacture these materials, the compound incorporates compatibilizers, which allow dissimilar polymers to mix evenly, Additionally, they assist in the incorporation of fillers and additives, such as wood flour, calcium carbonate, and pigments. 

Certain metal salts effectively reduce the photoactivity of titanium dioxide pigments. Combination of these salts with an appropriate antioxidant and/or ultraviolet stabilizer provided highly efficient stabilization of polypropylene. The deactivation/ stabilization performance of the metal salts is adequately explained on the basis of their decomposition of hydrogen peroxide at the pigment surface and by annihilation of positive holes in the pigment crystal lattice. 

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