Aliphatic/aromatic resin tackifiers

A more quantitative estimation of compatibility can be obtained with the solvent cloud point test. The solvent cloud point is based on the idea that resins will be compatible with elastomers of similar chemical nature. Thus aliphatic resins will be effective tackifiers for aliphatic elastomers, such as natural rubber, while aromatic solvents are needed for aromatic elastomers, such as SBR. Solvent cloud point tests are carried out in three solvent systems which represent aliphatic, aromatic, or polar systems [16j ... 

Petroleum resins are a by-product of oil refining. Like hydrocarbon resins, a range of grades are produced. Aliphatic resins, which contain oligomers of isoprene, tend to be used as tackifiers, whereas aromatic resins, which also contain high levels of dicyclopentadiene, tend to be classed more as reinforcing systems. 

Chem. Descrip. Aliphatic hydrocarbon resin Uses Processing aid tackifier for rubber paints/coatings ingred. Features Good heat and chem. stability lower cost than aromatics Properties Neat resin flake dens. 9.0 Ib/gal m.p. (R B) 100 C acid no. < 1 iodine no. 130 70% solids in toluene Gardner 9 color vise. (Gardner) 5... 

These studies demonstrate that in selecting resins to tackify either natural rubber or styrene-butadiene rubber, consideration must be given to the resin structure. An aliphatic resin is more likely to be compatible with natural rubber, while an aromatic resin would be compatible with styrene-butadiene rubber. 

Tackifying resins also come from petroleum feedstocks. These are broadly dassified as aromatic and aliphatic resins. The aromatic resins are based upon such materials as styrene, a-methyl styrene, methyl indene, indene, coumarone, and dicy-dopentadiene. Aromatic resins are sometimes called C-9 resins. The materials in various combinations are polymerized by much the same process as the pinenes. Some of the aliphatic resins are also called C-5 resins, as these are based upon pen-tene, cydopentene, ds- and tram-piperylene, isoprene, 2-methyl butene-2, and dicydopentadiene. An abbreviated list of conventional taddfying resins is shown in Table 1. 

Tackifiers. The tackifiers usually are hydrocarbon resins (aliphatic C5, aromatic C9) or natural resins (polyterpenes, rosin and rosin derivates, tall oil rosin ester). They improve hot tack, wetting characteristics and open time and enhance adhesion. The content on tackifiers in a hot melt can be in the region of 10-25%. 

Certain resinous materials that act as plasticizers are well noted for increasing the tack of the formulation. Traditional tackifiers were based on naturally occurring resins such as pine tar. Today, tackifiers used in modem adhesive formulations include aliphatic and aromatic... 

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