Phenol formaldehyde tackifying resins

Phenol formaldehyde tackifying resins (non-heat-reactive resins) are synthesized as... 

Figure 11.33 Synthesis of phenol formaldehyde tackifying resins...

Non-heat-reactive phenolic resins Phenol formaldehyde tackifying resins PF tackifier resin... 

Even though phenol formaldehyde tackifying resins are more expensive than most other tackifying resins such as the hydrocarbon type, they are commonly preferred because they impart better aged tack (they retain tack after storage). They are commonly used in the tire industry. 

Phenol reacts with olefins to produce f-butyl phenol, which reacts with formaldehyde to synthesize phenol formaldehyde tackifying resins. 

Phenolic Resins - Phenol-formaldehyde tackifying resins are linear short chain polymers which have limited heat stability, and so may cause discoloration if used in hot melt systems. 

Synonyms Butylated phenol-formaldehyde resin p-t-Butyl phenol formaldehyde resin Phenol formaldehyde butyl resin Uses Tackifier for rubbers, adhesives, cements ManufJDIstrib. Solutia Trade Names Containing Santolink EP 560... 

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. 

Phenolic resins are of two types, reactive and nonreactive. Nonreactive resins tend to be oligomers of alkyl-phenyl formaldehyde, where the para-alkyl group ranges from to C4 to C9. Such resins tend to be used as tackifying resins. Reactive resins contain free methylol groups. In the presence of methylene donors such as hexamethylenetetramine, crosslink networks will be created, enabling the reactive resin to serve as areinforcing resin and adhesion promoter. 

Resorcinol-formaldehyde resin Rosin Stoddard solvent Tall oil glycerides tackifier, SBR Alkyl phenol disulfide tackifier, sealants... 

Additives used in final products accelerator (MTBS) antidegradants (amine type), antioxidant curing agents (ZnO, Zn stearate) fillers (carbon black and mineral fillers, such as silica, clays, talc, whiting), peroxide (e.g. dicumyl) release agent (metal stearates), retarder (MgO) plasticizers (petroleum based oils), sulfur tackifying resins (phenolic, phenol-formaldehyde, phenol-acetylene, hydrocarbon resins UV stabilizer (carbon black) ... 

These phenol formaldehyde resin tackifiers can be replaced by less expensive hydrocarbon resins however, they may not impart adequate aged tack values. 

This is a premium tackifying resin vs. the conventional phenol formaldehyde resins already discussed. However, this more expensive tackifying resin is only used when better aged tack is needed in the factory. 

Under extreme conditions, sometimes this tackifying resin will outperform the phenol formaldehyde resin discussed earlier, especially for imparting better aged tack. 

Polyterpene resins are commonly used as tackifying resins to impart building tack to rubber compounds, especially if the compound is based on EPDM, which does not possess very much inherent tack. Polyterpene resins do not impart long-term aged tack as good as the phenol formaldehyde resins. 

The f-butylphenol reacts with acetylene to produce acetylene phenol tackifying resin. Also, f-butylphenol reacts with formaldehyde to produce PF tackifying resins. 

Tackifiers - Elastomers with little or no natural tack can be improved by the addition of resins or resin oils (natural abietie aeid derivatives), polyindene (coumarone-indene) resins, polyterpene resins and phenol-formaldehyde resins. 

Linear novolac resins prepared by reacting para-alkylphenols with paraformaldehyde are of interest for adhesive tackifiers. As expected for step-growth polymerization, the molecular weights and viscosities of such oligomers prepared in one exemplary study increased as the ratio of formaldehyde to para-nonylphenol was increased from 0.32 to 1.00.21 As is usually the case, however, these reactions were not carried out to full conversion, and the measured Mn of an oligomer prepared with an equimolar phenol-to-formaldehyde ratio was 1400 g/mol. Plots of apparent shear viscosity versus shear rate of these p-nonylphenol novolac resins showed non-Newtonian rheological behavior. 

Water-based dispersions or emulsions such as polyvinyl acetate, acrylics, polyvinyl chloride and polyvinyl alcohol with plasticizers and tackifiers. In addition, this range can include urea formaldehyde and phenolic adhesives, resins, natural adhesives produced from starch, dextrin, casein, animal glues (see Polyvinyl alcohol in adhesives, Phenolic adhesives single-stage resoles. Phenolic adhesives two-stage novolacs. Animal glues and technical gelatins) and rubber latex (see Emulsion and dispersion adhesives). Solvent-free 100% solids such as polyurethane. Hot melt adhesives include Ethylene-vinyl acetate copolymers, polyolefins, polyamides, polyesters with tackifiers and waxes. More recent additions include cross-linkable systems. 

Resins based on para-substituted phenols can be either one-step or two-step, but they cannot cure to a thermoset state. In the manufacture of phenolic resins, smaller quantities of acetaldehyde and furfuraldehyde are used in addition to formaldehyde. Furthermore, resorcinol, bisphenol A, and p-alkylphenols are employed, in addition to phenol, when special properties are desired. Formaldehyde concentrations of 37-50 weight % in aqueous solutions are most commonly employed. The catalysts most frequently used are acids such as oxalic, hydrochloric, sulfuric, p-toluenesul-fonic, and phosphoric and bases such as sodium, calcium, and barium hydroxide. In the weakly acidic range metal carboxylates are employed. Thermoset phenolic resins are employed as structural adhesives for laminating and bonding applications. Para-alkyl-substituted resins are employed as tackifiers in contact adhesives, pressure-sensitive adhesives, and hot-melt adhesives. 

Resins such as coumarone resins are able to act as dispersants and tackifiers. Sometimes, reactive reinforcing phenolic resins are also used, in which case if the crosslinking component (e.g., hexamethylene tetramine or other formaldehyde donors) is used, it must be added in the second stage together with the accelerators. 

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