Rosin based resins

Filtr Setalin. [Akzo Coatings] Rosin-based resins. 

As with most of the other sections of this chapter, the basic reference to the applications of rosin and its derivatives as components of adhesive formulations up to the mid-1980s, is the corresponding chapter by Kennedy et al. [73] of the classical Naval Store book. The major emphasis in that chapter was placed on the tackifying properties of rosin-based resins in pressure-sensitive, hot melt and sealant adhesives. Therefore, before proceeding to a critical bibliographic survey, it seems appropriate to define the concept of tack and its repercussion in the broad area of adhesion, as opposed to other contexts, like printing inks, paints and coatings. 

A recent interesting addition to this realm is the use of rosin-based resins in the manufacture of the new generation of inkjet inks, the phase-change inks [118]. 

Rosin and Rosin Derivatives. The main component of rosins are rosin acids with two double bonds the molecule. They can be stabilized by hydrogenation or disproportionation. The softening temperature can be varied over a wide range by esterification, from the methyl ester (liquid) to the pentaerythritol ester (ca. 110 °C). Still higher temperatures are achieved by oligomerization. Rosin-based resins have a broad range of compatibilities. 

Water soluble styrene acryHcs are processed via free radical polymerization in glycol ether solvents. The solvent is stripped by conventional or proprietary processes. Rosin based resins are processed molten at high temperatures up to 265 °C. These materials are flaked or pelletized and packaged in bags or bulk storage for further conversion. 

Rivera, M. A. Zuraw, P. J., Westvaco Corporation, US Patent 5,216,064, Rosin-Based Resin-Fortified Emulsion Polymers... 

Composition. Rosin is primarily a complex mixture of monocarboxyUc acids of alkylated hydrophenanthrene nuclei. These constituents, known as resin acids, represent about 90% of rosin. The resin acids are subdivided into two types, based on their skeletal stmcture. The abietic-type acids contain an isopropyl group pendent from the carbon numbered 13. The pimaric-type acids have a methyl and vinyl group pendent from the same carbon atom. Figure 1 shows the stmcture of typical resin acids abietic acid, C2QH2QO2 (1) is predominant. The remaining 10% of commercial rosin consists of neutral materials that are either hydrocarbons or saponifiable esters. These materials are derived from resin acids by decarboxylation or esterification. 

Butyl phenolic resin is a typical tackifier for solvent-borne polychloroprene adhesives. For these adhesives, rosin esters and coumarone-indene resins can also be used. For nitrile rubber adhesives, hydrogenated rosins and coumarone-indene resins can be used. For particular applications of both polychloroprene and nitrile rubber adhesives, chlorinated rubber can be added. Styrene-butadiene rubber adhesives use rosins, coumarone-indene, pinene-based resins and other aromatic resins. 

Odour. This aspect is important in resins derived from natural sources. Rosins based on wood and gum rosin retain trace quantities of terpenes and have a piney odour. Tall oil rosins retain the typical sour odour of the rosin. Odour can be removed by steam sparging under vacuum before or during esterification of rosins. Addition of odour masks can also be done. 

G-L. Griffith, G.A. Lyte F.B. Wells, USP 3366053(1968) CA 68, 70809(1968) [Free-flowing, inorg nitrate based expl mixts sensitized to initiation by incorporation of 1—4% powd Al and 1—6% water, are described. Expl sensitizers, such.as NS (preferred), NG, TNT, PETN, RDX, Pentolite or Comp B 5-7, carbonaceous fuels 0.4, stabilizers-antacids (such as CaCO a or MgO) up to 0.4, and materials (such as rosin, metallic resinates, hexamine, waxes or mineral oil) 0.4% could also be present. A mixt listed in CA contg AN 70.68, NaN03 8.91, Al powd 1.57, NS... 

The resins examined in this work are described in Table 1. The rosin-based products were prepared by esterification of hydrogenated rosin. Theterpene, aromatic, and Cg-stream resins were prepared by cationic polymerization. 

The most important rosin derivatives used in printing ink formulations are rosin oligomers and their esters, metal resinates, modified phenolic and alkyd resins, ester gums, maleic and fumaric acid adducts and their esters. Practically all types of printing inks can be manufactured with rosin-based components, because they provide good miscibility and compatibility with most film formers and other ink additives. 

Microparticles. Size matters release rates depend on surface area, ie, a function of the square of the radius of a spherical particle, and thus larger particles release for longer and are able to manipulate the external availability of the pesticide. Small microparticles are therefore limited in their scope for controlling release but can be used in traditional spraying of dispersions onto soils and crops as well as for seed dressing. Suspension concentrate formulations of matrix microparticles have been developed based on various rosins, phenoUc resins, waxes, and bitumens. These have focused on lipophilic pesticides such as trifluralin and chlorpyrifos and reductions in volatility have been demonstrated (43). 

Wang H, Wang H and Zhou G (2011), Synthesis of rosin-based imidoamine-type curing agents and curing behavior with epoxy resin , Polym Int, 60, 557-563. doi 10.1002/ pi.2978. 

The alkylphenolic resins are of more interest than the corresponding novolacs since they find application as modifying and cross-linking agents for oil varnishes and in the production of resins for coatings and printing inks based on rosin. Alkylphenolic resins are also used as antioxidants and stabilizers. 

The term rosin-based alkyd resins refers to alkyd resins in which all or a portion of the monobasic fatty acid is replaced by rosin (a mixture of diterpene resin acids and nonacidic components). Unmodified alkyd resins are polyester products composed of polyhydric alcohol, polybasic acid, and monobasic fatty acid. 

The term modified alkyd, which formerly was used to describe these products, now is associated with chemical modifications that are carried out during alkyd preparation, and that incorporate chemical agents of types other than those included in the definition. For example, the term rosin-based alkyd resins or rosin-modified alkyd refers to alkyd resins in which all or a portion of the monobasic fatty acid is replaced by rosin. Unmodified alkyd resins are polyester products composed of polyhydric alcohol, polybasic acid, and monobasic fatty acid. When no fatty acids are used, or when they are completely replaced by other types of acid, the products can be considered as oil-free alkyds. 

Tackifiers. Although SBRs can be produced with tack, the physical properties of such polymers usually do not fully satisfy the application requirements. For this reason tackifying resins are normally incorporated into adhesives based on SBRs. These resins improve the kinetics of wetting and increase the overall Tg of the adhesive composition. Typical tackifiers for SBR are rosin-based materials, aromatic-containing petroleum hydrocarbon resins, alpha-pinene, coumarone-indene, and some phenolic resins. 

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