Pigments polyurethanes

Striations unit area, e.g., pounds per square inch or MPa.) Lines of different color or intensity that are evident both in the unpigmented and pigmented polyurethane mixtures. 

Pigmented polyurethane coatings No effect on colors. In solutions with coales-cents, produces good films for transfer coating fabric laminates employing urethane-be adhesive tie coats. 

The major uses of aniline are in the manufacture of polymers, mbber, agricultural chemicals, dyes and pigments, pharmaceuticals, and photographic chemicals. Approximately 67% of the wodd production of aniline is used in the manufacture of rigid polyurethanes and reaction-injection-molded (RIM) parts for the constmction, automotive, and durable goods industries. 

Polyurethane sealant formulations use TDI or MDI prepolymers made from polyether polyols. The sealants contain 30—50% of the prepolymer the remainder consists of pigments, fiUers, plastici2ers, adhesion promoters, and other additives. The curing of the sealant is conducted with atmospheric moisture. One-component windshield sealants utili2e diethyl malonate-blocked MDI prepolymers (46). Several polyurethane hybrid systems, containing epoxies, siUcones, or polysulfide, are also used. 

Paints are complex formulations of polymeric binders with additives including anti-corrosion pigments, colors, plasticizers, ultraviolet absorbers, flame-retardant chemicals, etc. Almost all binders are organic materials such as resins based on epoxy, polyurethanes, alkyds, esters, chlorinated rubber and acrylics. The common inorganic binder is the silicate used in inorganic zinc silicate primer for steel. Specific formulations are available for application to aluminum and for galvanized steel substrates. 

Both pigmented and unpigmented polyurethane paints have been prepared using a polyester resin containing hydroxyl functional groups and the biuret trlmer of hexamethylenedllsocyanate as a crosslinker. The molar ratio of hydroxyl/isocyanate has been chosen 1.0 and the pig-ment/binder ratio 0.6. 

P.Y.62 is thermally stable up to 250°C. It has a considerable effect on the shrinkage of HDPE and other partially crystalline polymers. The pigment is an equally suitable colorant for polystyrene and polyurethane and lends color to polypropylene spin dyeing products with minimal application requirements. 

P.O.34 is rarely used in polyolefins. In such media, it only withstands exposure to 200°C, and its opaque colorations show insufficient lightfastness. P.O.34 tends to bloom, especially in extrusion products made of low molecular weight LDPE types. The pigment is, however, recommended for a variety of other media. These range from aromatic polyurethane foams to cast resins of unsaturated polyester, in which the pigment slightly delays the hardening process. 

P.R.164 was also found in cast resin composed of methacrylate and unsaturated polyester. The pigment does not affect the hardening process of such media, which may be carried out, for instance, by using peroxides. An important field of application was in the coloration of various polyurethanes, for which the pigment was also sold in the form of a pigment preparation. 

The plastics industry uses P.R.222 primarily in polyurethane. The pigment exhibits average tinctorial strength. 1/3 SD colorations in HDPE, for instance (1% TiOz), are formulated at 0.23% pigment concentration. 

Several benzimidazolone pigments are suitable candidates for use in powder coatings based on polyester, acrylic, or polyurethane resin. These pigments satisfy the heat requirements of this application and do not plate out in these media (Sec. 1.6.4.1). Various benzimidazolone pigments even meet the particularly high thermal standards of coil coating. These pigments are also suitable for use in architectural and emulsion paints. 

P.R.208 is also used in polyacrylonitrile spin dyeing. It exhibits excellent textile fastness properties and shows good lightfastness. Full shades (3% pigment concentration) equal step 7 on the Blue Scale, while very light (0.1% pigment) red specimens match step 5. The list of applications includes secondary acetate spin dyeing and mass coloration of polyurethane foam and elastomers. P.R.208 is inert to peroxides. 

P.R.248 exhibits excellent bleed resistance in plasticized PVC. Transparent specimens equal step 8 on the Blue Scale for lightfastness, while 1/3 SD samples match step 7. The pigment does not perform as well in terms of weatherfastness, for instance in PVC plastisols for coil coating. P.R.248 was also recommended for use in elastomers, polyurethane, and unsaturated polyester. 

In practical application, most types of P.B.15 1 are completely fast to overcoating in oven drying systems. The pigments are suitable candidates for powder coatings, for instance for acrylate or polyurethane-based systems, in which they do not exhibit plate-out (Sec. 1.6.4.1). 

Figure 5. Potential vs time for coated specimens in 3% NaCl. Key , bitumen A, Zn rich + bitumen 0> polyurethane, one coat (unpigmented) V, polyurethane, two coats (unpigmented) 0, polyurethane, one coat (pigmented) and X, polyurethane, two coats (pigmented).

A very wide range of plastics are coloured with pigments including PVC, polystyrene, polyurethane, polyamide, polycarbonate, polyester, elastomers, thermosets and thermoplastics. The choice of pigment is obviously dependent on which plastic... 

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