Lightness color properties

When petroleum occurs in a reservoir that allows the cmde material to be recovered by pumping operations as a free-flowing dark-to-light colored hquid, it is often referred to as conventional petroleum. In some oil fields, the downhole pressure is sufficient for recovery without the need for pumping. Heavy oil differs from conventional petroleum in that its flow properties are reduced and it is much more difficult to recover from the subsurface reservoir. These materials have a much higher viscosity and lower API (American Petroleum Institute) gravity than conventional petroleum, and primary recovery of these petroleum types usually requires thermal stimulation of the reservoir. 

Properties of lakes that enhance their usefiilness iaclude their opacity, their abiUty to be iacorporated iato products ia the dry state, their relative iasolubihty, and their superior stabiUty toward heat and light. Such properties have made possible the more effective and more efficient preparation of candy and tablet coatings, and often eliminate the need to remove moisture from dry products before coloring them. Lakes have also made possible the coloring of certain products that, because of their nature, method of preparation, or method of storage, caimot be colored with ordinary color additives. 

Amino (melamine and urea) Melamine formaldehyde (MF) have excellent electrical properties, heat and moisture resistance, abrasion resistance (good for dinnerware and buttons) in high-pressure laminates it is resistant to alkalies and detergents. They are used as the plastic for counter tops. Urea (urea formaldehyde) has properties similar to melamine and is used for wall switch plates, light-colored appliance hardware, buttons, toilet seats, and cosmetics containers. Unlike MFs they are translucent, giving them a brightness and depth of color somewhat similar to opal glass. 

For preparing lakes, a solution of aluminium sulfate (or chloride) is mixed with sodium carbonate, forming fresh alumina Al(OH)3. The colorant is then added and adsorbed on the surface of alumina. Usually the content of colorant in the lake ranges from 10 to 40%." The product is filtered, washed with water, dried, and milled. The product is allowed to contain unreacted alumina but must not contain more than 0.5% HCl-insoluble matter and not more than 0.2 % ether-extractable matter. - Lakes are insoluble in most solvents used for pure dyes, and they have high opacity and better stability to light and heat. Lakes impart their color by dispersion of solid particles in the food. The coloring properties of lakes depend on particles, crystal structures, concentrations of dye, etc. 

The effect of particle size, and hence dispersion, on the coloring properties of aluminum lake dyes has been studied through quantitative measurement of color in compressed formulations [47], It was found that reduction in the particle size for the input lake material resulted in an increase in color strength, and that particles of submicron size contributed greatly to the observed effects. Analysis of the formulations using the parameters of the 1931 CIE system could only lead to a qualitative estimation of the effects, but use of the 1976 CIEL m v system provided a superior evaluation of the trends. With the latter system, the effects of dispersion on hue, chroma, lightness, and total color differences were quantitatively related to human visual perception. 

Polymer Structure, Transmittance and Birefringence. There is a great deal of variability in the light transmission properties of polymers. Some of this variability is due to structural differences, and some is dne to the presence of fillers and colorants that are purposely added to make otherwise transluscent polymers appear opaque. We will focus for the moment on strnctnral differences in polymers that lead to differences in the transmission of light. 

The polymer requires compounding with normal fillers to produce useful compounds. Chlorosulfonated polyethylene (CSM) excels in resistance to attack by oxygen, ozone, corrosive chemicals, and oil, and in addition has very good electrical properties. Electrical stability and resistance to corona and arc are good. The physical properties and abrasion resistance are also good. Light-colored goods made from CSM have excellent color-fastness. Due to the presence of chlorine atoms, this elastomer shows excellent flame resistance. 

Alkylbenzenesulfonic acids are light-colored, viscous liquids whose alkali and ammonium salts are soluble in water. The salts are neutral, relatively unaffected by water hardness, and stable toward alkaline and acid hydrolysis. Calcium and magnesium alkylbenzenesulfonates are less water-soluble than sodium or ammonium salts. They are, however, soluble in hydrocarbons and are used extensively in these media. LAS salts are stable to oxidation and can be incorporated in formulations containing oxidizing agents. Pure alkylbenzenesulfonates have been synthesized for property studies (60,61). 

Opalescence is a pearly or milky internal reflection, most common in white or light-colored minerals such as some opal or moonstone (albite or ortho-clase feldspar). This is also known as adularescence. Like iridescence and play of color, these properties are not consistent within any natural material, and can only be used to describe individual specimens. Some synthetic materials have been created specifically to display these properties and so always show them. 

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