282 index paint

Part II Function/Application Index paint modifier... 

Poly(vinyl acetate) is too soft and shows excessive cold flow for use in moulded plastics. This is no doubt associated with the fact that the glass transition temperature of 28°C is little above the usual ambient temperatures and in fact in many places at various times the glass temperature may be the lower. It has a density of 1.19 g/cm and a refractive index of 1.47. Commercial polymers are atactic and, since they do not crystallise, transparent (if free from emulsifier). They are successfully used in emulsion paints, as adhesives for textiles, paper and wood, as a sizing material and as a permanent starch . A number of grades are supplied by manufacturers which differ in molecular weight and in the nature of comonomers (e.g. vinyl maleate) which are commonly used (see Section 14.4.4)... 

The ratio PVC/CPVC (or reduced CPVC) is a simple but profound index of primer film structure that is perhaps the most important parameter in all of paint technology [70]. The relationship of the reduced CPVC to film structure can be appreciated by reference to Fig. 8. This figure shows a representation of a dry primer film with a range of pigment volume fraction that increases from left to right. 

Extender an inorganic material in powder form which has a low refractive index and consequently little obliterating power, but is used as a constituent of paints to adjust the properties of the paint, notably its working and film-forming properties and to avoid settlement on storage. 

The analysis of the contribution made by increased pharmaceutical spending to the growth in the per capita intensity of health resources suffers from major measurement problems that deprive available indicators of any value. Traditional pharmaceutical price indexes (such as the Laspeyres index, used to calculate the pharmaceutical component of the consumer price index) provide little relevant information in a market in which the introduction of therapeutic innovations is of prime importance the indexes show an apparent freeze, and sometimes even a steep drop (as in the Spanish case). However, the steady rise in the average price per prescription paints a very different picture. 

A film of paint, 3 mm thick, is applied to a flat surface that is inclined to the horizontal by an angle 9. If the paint is a Bingham plastic, with a yield stress of 150 dyn/cm2, a limiting viscosity of 65 cP, and an SG of 1.3, how large would the angle 9 have to be before the paint would start to run At this angle, what would the shear rate be if the paint follows the power law model instead, with a flow index of 0.6 and a consistency coefficient of 215 (in cgs units) ... 

The ratio of oleic acid to stearic acid (O/S) is another parameter used for assessing the degree of ageing of a lipid paint binder. This ratio is considered as an index of oxidation because the oleic acid double bond is particularly reactive towards oxidation, so normally the content of oleic acid in aged paintings is very low, with an O/S value around 0.1 0.2 [55]. 

The refractive index of these pigments is about 1.5, which means that they give a transparent blue when used in paints and clear plastics. Opacity can be increased by adding small amounts of titanium dioxide. The principal failing of ultramarine is its lack of resistance to acid, which can even decompose the pigment if there is sufficient available. Coated grades are made with substantially improved acid resistance. 

In the case of paints and printing inks, the initial preparations will be in the semi-solid state because solvents are needed both in the process of dispersing the pigment in the paint or ink medium and for application purposes. These solvents dry out after the paint or ink is applied. When making coloured plastic articles, both heating and solvents may be used to aid dispersion in the plastic medium as part of the moulding process. However, from the viewpoint of the optical properties in all of these pigment uses, what is most important is that each of these media has a refractive index close to 1.5. 

---