Modified rosin

Rosin, modified rosins, and derivatives are used in hot-melt adhesives. They are based primarily on ethylene—vinyl acetate copolymers. The rosin derivative is used in approximately a 1 1 1 concentration with the polymer and a wax. The resin provides specific adhesion to the substrates and reduces the viscosity at elevated temperatures, allowing the adhesive to be appHed as a molten material. 

The soap of modified rosin has a long history as an emulsifier for the polymerization of styrene—butadiene mbber. The rosin soap remains in the mbber after polymerization and increases the tack between the pHes of mbber required in the manufacture of tires. 

The formulation of calcium chelate materials is based upon the formation of a low-solubiUty chelate between calcium hydroxide and a sahcylate. Dycal utilizes the reaction product of a polyhydric compound and sahcyhc acid. Other sahcyhc acid esters can be similarly used. Vehicles used to carry the calcium hydroxide, extenders, and fillers may include mineral oil, A/-ethyl- -toluenesulfonamide [80-39-7] and polymeric fluids. The filler additions may include titanium dioxide [13463-67-7] zinc oxide, sihca [7631-86-9], calcium sulfate, and barium sulfate [7727-43-7]. Zinc oxide and barium sulfate are useflil as x-ray opacifying agents to ensure a density greater than that of normal tooth stmcture. Resins, rosin, limed rosins, and modified rosins may serve as modifiers of the physical characteristics in both the unset and set states. 

Tackifiers. Resins are generally added to adjust the desired tack. In general, resins must be used with plasticizers to obtain a good balance between tack and cohesive strength. Typical tackifiers are polyterpenes, although hydrocarbon resins and modified rosins and rosin esters can also be used. In some cases, terpene-phenolics or phenol-formaldehyde resins are added to increase adhesion. 

Laboratory handmade ° Modified rosin. 33.3% refined rag 33.3%bleached kraft 33.3% bleached sulfite 5.3 1% Neuphor 3% alum... 

The effect of acidity caused by alum-rosin size has been obviated by the substitution of sizing agents which are effective slightly on the alkaline side of neutrality. It has been established that papers of satisfactory permanence can be manufactured with such sizes. It is possible to use rosin as a size and to avoid the conjunction with alum by a number of processes. There are insufficient data on the aging characteristics of paper sized with the available modified rosin sizes to judge the effect on permanence. Possible reactions of the rosin, such as oxidation and formation of peroxides, must be considered. 

The adhesives industry is the third most important market for rosin. Rosin, modified rosins, and rosin derivatives are used in several types of adhesives, including the pressure-sensitive, hot-melt, and elastomer-based latices, and solvent rubber cements. 

Dresinate [Aqualon]. TM for liquid, paste, and powder forms of sodium and potassium soaps of rosins and modified rosins used as emulsifiers, detergents, and dispersants in soluble oils, cleaning compounds, and other compositions. 

Neolyn [Aqualon], TM for a series of soft-to-medium hard modifying rosin-derived alkyd resins. Available in solution and/or solid forms of various grades. 

As the cylinder rotates in the press, the lower part of the cylinder is flooded with ink having a viscosity in the low centipoise range. The press ready ink may contain 7% pigment, 18% binder, such as modified rosins, nitrocellulose or a synthetic resin and 75% solvent. The solvents are usually blends of such materials as aliphatic hydrocarbons in the heptane range, toluene, acetates and alcohol. Water based systems are used in a number of applications. 

The carboxylic acid group in rosin undergoes the usual ester and amide formation with alcohols and amines (Figure 9). A large number of compositions can be prepared from various rosins and modified rosins. 

Beckacite. [Arizona] Phenolic modified rosin ester resins for lithographic printing inks. 

Malkyd. [Arakawa] Maldc modified rosin ester. 

Super Ester. [Arakawa] Modified rosin ester. 

Chem. Desaip. Hydrocarbon-modified rosin ester Uses Resin for adhesives and paints/coatings Properties Neat resin dens. 9.0 Ib/gal m.p. (R B) 100 C acid no. 25 iodine no. 120 60% solids in Magiesol 47 Gardner 12 color vise. (Gardner) 2... 

Stclair W.E., Minor J.C., Lawrence R.V., Fused metal resinates from aldehyde-modified rosin, Ind. Eng. Chem., 46(9), 1954, 1973-1976. 

Hydrogenated rosin n. Modified rosin obtained by the hydrogenation of rosin at high pressures in the presence of a catalyst. 

Karlberg A-T, Gafvert E, Hagelthorn G, et al. (1990) Maleopim-aric acid - a potent sensitizer in modified rosin. Contact Dermatitis 22 193-201... 

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