Early color

Early color copiers and printers used multiple copy cycles for each page output, using colored fdters and toners. Modem units use only a single scan to four separate, miniature process units, operating simultaneously, each with its own coronas, drum, and developer unit. 

The perceptibility of observers varies and is not the same for all colors. David MacAdam developed early color data in 1942. The MacAdam ellipses (Fig. F5.1.13) are plotted in the CIE 1931 chromaticity diagram. The ellipse... 

The first generation tin mercaptide stabilizers were dialkyltin long-chain mercaptans (1), traditional mercaptoacetate products (2), and mercaptoacetic ester products, having an average tin content of 18% in the stabilizer. When a stabilizer with a high content of a monoalkyltin compound derived from a mercaptoethanol ester (3), was demonstrated to provide outstanding early color and color retention in white pipe, the industry quickly accepted this departure from traditional mercaptoacetate products. 

Mono-n-butyltin tris(j-octylmercaptoacetate) combines improved early color with shortened longterm stability. This is due to its intermediate Lewis acid character between that of diisooctyl bis(t-octylmercaptoacetate) and tin tetra(i-octylmercaptoacetate). The decreased effectiveness of tri-n-butyltin i -octylmercaptoacetate may be ascribed to the increased reluctance to coordination by the tin atom, due to presence of the third alkyl (n-butyl) group. Additionally, the use of trialkyltin derivatives in PVC stabilization has been avoided because of their toxicity. 

The most important costabilizers in PVC formulations used mainly in combination with mixed metal salts are alkyl-aryl-phosphites to improve early color. Epoxy compounds, for example, epoxidized fatty esters such as epoxidized soy bean oil, react directly with HCl or substitute labile chlorine atoms, for example, in the presence of zinc ions. Furthermore, the epoxidized fatty esters act as plasticizers. Polyols such as pentaerythritol or dipentaerythritol and P-diketones act as complexing agents and deactivate the negative effect of the formed zinc chloride. Hydrotalcites... 

The phosphite esters function in this formulation as primary heat stabilizers by replacing labile chlorides on PVC via the Arbuzov rearrangement mechanism. When phosphites are used at optimized levels in combination with catalytic amounts of zinc and normal levels of epoxidized soybean oil, they provide excellent early color and adequate long-term stability to flexible PVC compounds. Their use also helps in lowering stabilization cost, elimination of toxic metals, elimination of plate out, poor printability, viscosity drift in plastisols, haze, bloom, water blush, and staining. 

Pationic 1033 is used as an additive to PVC, polyolefins, and styrenics. The product is an excellent internal lubricatnt for PVC that helps maintain clarity and early color hold. It is also a common component in PVC antifogging formulations to promote better compatibility between the resin and the hydrophilic component of the formulation. In polyolefins, Pationic 1033 functions as a flow modifier and an additive dispersing agent. 

Based upon this law, color comparison instruments soon developed. One of the first instruments to use the absorption of light to determine concentration was the visual color comparator. The user visually compared the transmitted light from the sample and a standard solution and adjusted the path length until the transmitted light from both solutions appeared to have the same intensity [50]. Figure 6.7 shows an early color comparator called a Duboscq Colorimeter. 

Ehrlich s Early Colorful Work with Histological Staining... 

Liquid stabilizers may also contain low levels of diphenyl phosphite (Weston DPP) specifically to reduce plateout through chelation of reaction products containing barium. The use of an active aryl phosphite such as diphenyl or triphenyl phosphite (Weston TPP and Doverphos 10) adds to early color and brightness, but is of little value in extended color retention as compared with aryl-alkyl phosphites that undergo the Arbuzov reaction. A liquid stabilizer composed of about half phosphite, as is common, will usually have no more than a few percent of triaryl phosphite, most often DPP, the balance either aU a phenyl isodecyl phosphite, or a blend with a hydrolysis-resistant grade. The development of more sophisticated use of phosphites has been a major factor in the replacement of cadmium in mixed metal stabilizers. 

Features Helps maintain clarity and early color hold Regulatory FDA 21CFR 184.1505, GRAS Properties Amber vise. liq. 19 C m.p. 39-41 C 44% a-monoglyceride Pationic 1068 [Caravan Ingreds.)... 

Product Attributes Early Color Hold Excellent Long Term Stability Good High Flash Liquids), ESO Compatibility... 

Types Liquid, Primary Stabilizer Processes Plastisol Applications General Purpose Product Attributes Early Color Hold Good... 

Product Attributes Early Color Hold Excellent... 

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