Setting alkyd

Web Heat-Set Publication and Commercial Inks. Almost all heat-set inks are now printed on web offset presses, and are based on vehicles containing synthetic resins and/or some natural resins. These are dissolved in hydrocarbon solvent fractions which are specially fractionated for use in the ink industry. They vary in boiling range between 180 and 300 °C. Small percentages of alkyd resins (qv) may be contained in these inks. They dry in less than one second by means of solvent evaporation in a heatset oven. These ovens utilize high velocity hot air to raise the web temperature to 120-150 °C. 

Trimethyl-l,3-pentanediol (TMPD), the hydrogenated aldol condensation product of isobutyraldehyde, is a modifying agent in alkyd resins (qv), high sohds coatings, and moisture-set inks. 

Fig. 2.3.5 Profiles recorded from a drying alkyd left. The Peclet number is defined as HE/D emulsion layer are shown on the right. At low where H is the film height, the evaporation Peclet number (upper set of profiles), drying is rate and D the particle diffusivity. The upper set...

The glyptals made from phthalic anhydride and glycerol were developed as compositions for use in paints and varnishes. If the reaction was carried out too long the product became intractible. But under milder conditions, other products could be obtained which could be used in making soluble products and then they could be set further after forming. It was learned that by modifying the reaction mixture with some monobasic acid to balance the hydroxyls and carboxyls in the reaction mixture, more soluble products could be obtained. Kienle of General Electric, was one of the early developers of these products. Later many other alkyd resins from other polyhydroxyl compounds and poly acids were produced for technical use. 

As noted earlier, oil-modified alkyds contain free hydroxyl groups, and these groups represent sites for reaction with polyisocyanates. The resultant products possess faster drying, better chemical resistance, and abrasion resistance. Rosin is frequently used in a monobasic acid modifier to replace a portion of the oil fatty acids. As such, it promotes hardness, fast set, and solubility but impairs color, color retention, and durability, depending on the quantity used. Small amounts (up to 5%) improve the solubility without detracting from other properties to any significant degree. 

Thermo set polymers Alkyd resins Amino resins Epoxy resins Phenolic resins Poly(bis maleimide) Polyesters, unsaturated Thermoset resin Tohprene TOR Torelina Torlon TP 301 TPX... 

Tris (hydroxymethyl) propane 1,1,1-Tris (hydroxymethyl) propane. See Trimethylolpropane 1,1,3-Tris (hydroxyphenyl) propane Synonyms Tri phenol P Empirical C21H20O3 Formula (C6H40H)2CHCH2CH2C6H40H Properties Wh. solid dens. 1.226 (20/20 C) f.p. 90-110 C, sets to glass below 90-110 C Precaution Combustible Uses Antioxidant, intermediate for polyester and alkyd resins... 

An optical microscope will provide magnifications of up to a x 1000, albeit with a limited depth of field and the setting up procedure for a microscope required for laboratory work is described in Chapter 17, Section 17.10.1. Typical metallurgical techniques are used for mounting specimens such as hot pressing in a phenolic or alkyd resin or potting in a cold... 

Type Poly- ethylene Chlorinated Rubber Chlorosul-fonated Chloro- Polyethy-prene lene Eluoro- carbon Urethane Vinyl Vinyl- Alkyd (Approx 1 1) Polyester Alkyd (Oil-free) Acrylic (Thermo- setting)... 

Although telephone instruments have existed for nearly 90 years, all the early versions were constructed of wood and metal and it can be said that plastics played little if any part in telephone development until 1929 when the first compression moulded sets were introduced. Subsequently very large numbers of black phenolic and coloured alkyd telephone body and handset mouldings were produced. 

Certain significant differences are also observed for alkyds that are identical from a chemical composition standpoint but differ in properties and performance depending on whether they are made by alcoholysis or the fatty acid method rate of esterification slows down at somewhat higher acid number bodying and gelation occurs at slightly higher acid numbers air-dry set time is somewhat slower, and the resin tolerates more aUphatic thinner. 

The application of isophthalic acid as a raw material in the synthesis of alkyd resins involves the alcoholysis of the oil with the pentaerythritol in long-oil alkyds, and with a 65 35 pentaerythritol—ethylene glycol—equivalent blend in the medium-oil-length alkyd using a 15—20% excess of hydroxyl content. A water-cooled reflux condenser should be used during the alcoholysis. On completion of the alcoholysis, the reaction mixture is cooled to 200°C, and isophthalic acid added. With equipment set up to prevent loss of glycol, the temperature is slowly... 

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