Soluble resins

An emulsifying agent generally produces such an emulsion that the liquid in which it is most soluble forms the external phase. Thus the alkali metal soaps and hydrophilic colloids produce O/W emulsions, oil-soluble resins the W/O type (see emulsion). 

Me3CCH2CMe2C H40H. M.p. 8l-83"C, b.p. 286-288°C. Made by alkylation of phenol. Forms oil-soluble resins with methanal (salts used as oil additives) and surfactants (with ethylene oxide). 

Reaction of one mole of acetaldehyde and excess phenol in the presence of a mineral acid catalyst gives l,l-bis(p-hydroxyphenyl)ethane [2081-08-5], acid catalysts, acetaldehyde, and three moles or less of phenol yield soluble resins. Hardenable resins are difficult to produce by alkaline condensation of acetaldehyde and phenol because the acetaldehyde tends to undergo aldol condensation and self-resinification (see Phenolic resins). 

Heat-reactive resins are more compatible than oil-soluble resins with other polar-coating resins, such as amino, epoxy, and poly(vinyl butyral). They are used in interior-can and dmm linings, metal primers, and pipe coatings. The coatings have excellent resistance to solvents, acids, and salts. They can be used over a wide range of temperatures, up to 370°C for short periods of dry heat, and continuously at 150°C. Strong alkaUes should be avoided. 

Fig. 9. Melt flow index as a function of temperature for varying molecular weights of poly(ethylene oxide). WSR = Polyox water-soluble resins.

Considerable interest has been shown ia poly(ethylene oxide) for diverse appHcations ia food, drug, and cosmetic products. Such uses fall within the scope of the Federal Food, Dmg, and Cosmetic Act. The U.S. FDA has recognized and approved the use of poly(ethylene oxide) for specific food and food packaging uses. USP/NF-grades of Polyox water-soluble resins (Union Carbide Corp.) are available for pharmaceutical appHcations. 

Resin Solubilizers. In general, water-soluble resins ate amine salts of acidic polymers. Water-soluble coatings formulated with AMP-95 and DMAMP-80 exhibit superior performance (15,16) (see Water-SOLUBLE polymers). AMP-95, used in conjunction with associative thickeners (17) or hydroxy-ethylceUulose, provides for the most efficient utilization of such thickeners. It also is the neutralizer of choice for use with hair spray resins. 

Alkylated phenol derivatives are used as raw materials for the production of resins, novolaks (alcohol-soluble resins of the phenol—formaldehyde type), herbicides, insecticides, antioxidants, and other chemicals. The synthesis of 2,6-xylenol [576-26-1] h.a.s become commercially important since PPO resin, poly(2,6-dimethyl phenylene oxide), an engineering thermoplastic, was developed (114,115). The demand for (9-cresol and 2,6-xylenol (2,6-dimethylphenol) increased further in the 1980s along with the growing use of epoxy cresol novolak (ECN) in the electronics industries and poly(phenylene ether) resin in the automobile industries. The ECN is derived from o-cresol, and poly(phenylene ether) resin is derived from 2,6-xylenol. 

For aqueous inks, the resins are water- or alkali-soluble or dispersible and the solvent is mosdy water containing sufficient alcohol (as much as 25%) to help solubilize the resin. To keep the alkah-soluble resin in solution, pH must be maintained at the correct level. Advances include the development of uv inks. These are high viscosity inks that require no drying but are photocurable by uv radiation. In these formulations, the solvent is replaced by monomers and photoinitiators that can be cross-linked by exposure to uv radiation. The advantage of this system is the complete elimination of volatile organic compounds (VOC) as components of the system and better halftone print quaUty. Aqueous and uv inks are becoming more popular as environmental pressure to reduce VOC increases. 

Fractionation. Kett-McGee developed the ROSE process for separating the heavy components of cmde oil, eg, asphaltenes, resins, and oils, in the 1950s. This process was commercialized in the late 1970s, when cmde oil and utility costs were no longer inexpensive. In the ROSE process (Fig. 11), residuum and pentane ate mixed and the soluble resins and oils recovered in the supetctitical phase. By stepwise isobatic temperature increases, which decrease solvent density, the resin and oil fractions ate precipitated sequentially. 

Poly(viayl alcohol) (PVA), a polyhydroxy polymer, is the largest-volume synthetic, water-soluble resin produced in the world. It is commercially manufactured by the hydrolysis of poly(vinyl acetate), because monomeric vinyl alcohol caimot be obtained in quantities and purity that makes polymerisation to poly(vinyl alcohol) feasible (1 3). 

DAVIDSON, R.L., and siTTiG, M., Water-soluble Resins, Reinhold, New York (1962)... 

Unlike other water-soluble resins the poly(ethylene oxide)s may be injection moulded, extruded and calendered without difficulty. The viscosity is highly dependent on shear rate and to a lesser extent on temperature. Processing temperatures in the range 90-130°C may be used for polymers with an intrinsic viscosity of about 2.5. (The intrinsic viscosity is used as a measure of molecular weight.)... 

Xylenols, also obtained from coal tar, are sometimes used in oil-soluble resins. Of the six isomers (Figure 23.7) only 3,5-xylenol has the three reactive positions... 

Other higher boiling phenolic bodies obtainable from coal tar distillates are sometimes used in the manufacture of oil-soluble resins. Mention may also be made of cashew nut shell liquid which contains phenolic bodies and which is used in certain specialised applications. 

A few synthetic substituted phenols are also used in the manufacture of oil-soluble resins. They include p-tert-butylphenol, / -tert-amylphenol, p-tert-octylphenol, /7-phenylphenol and dihydroxyphenylpropane (bis-phenol A). 

Two classes of resol are generally distinguished, water-soluble resins prepared using caustic soda as catalyst, and spirit-soluble resins which are catalysed by addition of ammonia. The water-soluble resins are usually only partially dehydrated during manufacture to give an aqueous resin solution with a solids content of about 70%. The solution viscosity can critically affect the success in a given application. Water-soluble resols are used mainly for mechanical grade paper and cloth laminates and in decorative laminates. 

In contrast to the caustic soda-catalysed resols the spirit-soluble resins have good electrical insulation properties. In order to obtain superior insulation characteristics a cresol-based resol is generally used. In a typical reaction the refluxing time is about 30 minutes followed by dehydration under vacuum for periods up to 4 hours. 

Phenolic resins are useful surface coating materials. Resols are useful for stoving lacquers for coating chemical plant, textile equipment, razor blades, brassware cuid food cans. Phenolic resins are used with poly(vinyl formal) as a flexible, tough and solvent-resistant wire enamel. Oil-soluble resins based on synthetic phenols form the basis of some gloss paints. 

These probably form the basis of the amorphous precipitates formed on cooling. The more soluble resins produced on continuation of the reaction probably contain pendant methylol groups formed by reactions of the NH groups with free formaldehyde Figure 24.3 I). 

The latex of the Sapota achras yields a thermoplastic material, chicle, consisting of about 17.4% hydrocarbon, 40% acetone soluble resin and 35% occluded water. The hydrocarbon appears to contain both trans- and c/s-polyisoprene. Although originally introduced as gutta pereha and natural rubber substitutes, deresinated chicle has become important as the base for chewing gum. Like other polyisoprenes, it is meeting competition from synthetic polymers. 

Where resorcinol adhesives are not suitable, resins can be prepared from modified resorcinol [128], Characteristic of these types of resins arc those used for tyre cord adhesives, in which a pure resorcinol-formaldehyde resin is used, or alternatively, alkyl resorcinol or oil-soluble resins suitable for rubber compounding are obtained by prereaction of resorcinol with fatty acids in the presence of sulfuric acid at high temperature followed by reaction with formaldehyde. Worldwide more than 90% of resorcinol adhesives are used as cold-setting wood adhesives. The other most notable application is as tyre cord adhesives, which constitutes less than 5% of the total use. 

In order to prevent seepage loss of circulation to the vugular formation, bridging the formation—by properly sized, acid-soluble on oil-soluble resin particles as well as colloidal particles—should be considered. 

Fluid loss additives are used are used to reduce the rate of fluid loss from the fracture to the formation and to naturally occurring macro- and micro-fractures within the formation. Silica flour (73,74), oil-soluble resins (75), diesel oil emulsions (5% by volume) (74) have also been used. 

Militz, H. and Peek, R.D. (1993). Possibilities of improving some characteristics of poplar wood by impregnation with water-soluble resins. Material und Organismen, 28(1), 55-73. 

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