Color articles

In determining the chemical resistance, color changes of pigmented binder surfaces are measured after their exposure to various chemicals, such as water—sulfur dioxide or water—sodium chloride systems. These systems imitate the environment to which the colored articles could become exposed. 

An important application of P.Gr.8 is in the coloration of rubber. The pigment, however, is not suitable for use in blends which contain large amounts of basic fillers. It is somewhat sensitive to cold vulcanization. The colored articles usually perform well in general application but are not entirely fast to aromatic hydrocarbons and to some fats, and they are sensitive to acid and sulfur dioxide. P.Gr.8 also colors some plastics, especially LDPE and polystyrene. Heat stable up to 220°C, P.Gr.8 grades equal step 2-3 on the Blue Scale for lightfastness. Other areas of application include wallpaper and artists colors. 

Metamerism The condition that exists when two colored articles appear to match under one light source but not another. The three common light sources used in color matching are simulated daylight, incandescent, and cool white flourescent. 

Inspection of easily visible faults sorting distinctively colored articles by color factory... 

The polyesteresterketone can be of two t5 es simple (unarmored) and reinforced (armored) by glass. Usually both types are opaque though they can become transparent after treatment at certain conditions. This happens due to the reversible change of material s crystallinity which can be recovered by tempering. The limited number of tinges of polyesteresterketones has been produced for those areas of industry where color articles are used. 

S. Takahashi, Y. Dejima, and Y. Shirasaki, Water-soluble azo compound, ink composition, and colored article, US Patent 7 740 696, assigned to Nippon Kayaku Kabushiki Kaisha (Tokyo, JP), June 22,2010. 

Cadmium pigments are stable to 400 °C with only minimal degradation, allowing them to be used in the majority of polymers, and also allowing colored articles to be recycled. They have limited use in some polymers, such as silicone molding compounds, acrylic molding compounds and acetals. 

Much work has been done to determine levels of extractable cadmium leached from colored articles. This has been done to determine how much cadmium is likely to be released in food contact applications, and to predict cadmium release from waste products in landfill sites. It has been shown that in all but a few polymers insignificant levels of cadmium are leached out. 

Use of cadmium pigments in polymers is almost universal. Principal polymers of use include HOPE, polystyrene, polypropylene, nylon and ABS. Within Western Europe cadmium pigments are permitted for use in safety applications and in polymers that demand higher processing temperatures. They are also permitted in European toy applications, provided that the colored article conforms to soluble extraction limits of EN71 Part 3. Whereas in Europe the pigments are not permitted to be used in low-density polyethylene (LDPE), they can still be used in masterbatch, which can then be used to color unrestricted polymers. 

An irradiated object absorbs some of the radiation and transforms it into heat it becomes warmer relative to its environment. The temperature increase depends on properties specific to the material (e.g., degree of absorption, thermal conductivity) and on the spectral intensity of the impacting radiation. Table 2.10. Surface temperatures increase markedly as coloration changes from white to multicolored to brown and black. On dark colored molded parts in particular, surface temperatures up to 60°C and higher can be measured even in moderate climate zones. Because oxidative degradation reactions are dependent on temperature, accelerated oxidation is expected in dark colored articles [86]. 

Although CSM has good basic weather resistance, carbon black imparts improved UV resistance. Light-colored articles need to have up to 35 phr of a rutile titanium dioxide, depending upon other non-black fillers used, for good weather resistance and color stability. Non-black fillers recommended are clays up to 50 phr, whitings up to 200 phr, all in combination with titanium dioxide. Low levels of talc may be employed and silica fillers are NOT good for UV resistance. 

---