Alkyd resins modification

Rohm Haas Co. has suggested the use of methacrylates in alkyd resin modification [78]. 

These products are useful for modification of alkyd resins (qv), preparation of paint vehicles, and copolymeri2ation with other monomers. Substitution on the amino group occurs readily, giving bases stronger than the parent amines. 

Synthetic Applications. Oxazolines, which ate synthesized as indicated above, have been utilized in many different appHcations (25). When used in resin formulations, AMP, AEPD, and TRIS AMINO can incorporate the oxazoline stmeture into the polymer stmeture (26). Because they ate polyols, both AEPD and TRIS AMINO can be used in polyester resin modification. Oxazoline alkyd films ate characterized by improved performance, particularly salt-spray resistance and gloss (see Alkyd resins Coatings, special purpose, high performance). 

Modification of Alkyd Resins by Blending with Other Polymers... 

Although blending with other coating resins provides a variety of ways to improve the performance of alkyds, or of the other resins, chemically combining the desired modifier into the alkyd stmcture eliminates compatibiUty problems and gives a more uniform product. Several such chemical modifications of the alkyd resins have gained commercial importance. 

Stripping of top coats soaked by rain or sea-water has occurred with alkyd-resin-based paint systems, mainly on ships. The risk of such intercoat failure is reduced if the time interval between application of coats is reduced, but is best controlled by modification of the alkyd resin with a proportion of a different material. 

Modification of alkyd resins with high proportions of silicones considerably reduces rates of attack, but the most spectacular extension of life is shown by fluorinated polymers such as polyvinylidene fluoride where erosion rates can be reduced to 0 -1 /tm/year. If this level of durability can be achieved an initial coating, if firmly adherent and free from any breaks, may often be expected to maintain protection over a metal substrate for the likely life of the structure. The considerably increased first cost, as compared with more conventional coatings, has to be balanced against the probable saving in maintenance costs or consequences of failure. 

Several applications of hyperbranched polymers as precursors for synthesis of crosslinked materials have been reported [91-97] but systematic studies of crosslinking kinetics, gelation, network formation and network properties are still missing. These studies include application of hyperbranched aliphatic polyesters as hydroxy group containing precursors in alkyd resins by which the hardness of alkyd films was improved [94], Several studies involved the modification of hyperbranched polyesters to introduce polymerizable unsaturated C=C double bonds (maleate or acrylic groups). A crosslinked network was formed by free-radical homopolymerization or copolymerization. 

MODIFICATION OF ALKYD RESINS BY BLENDING WITH OTHER POLYMERS 343... 

Alkyd Resins. The phthalic alkyds class includes modifications with phenolics, maleic alkyds, adipic acid, and oils and fatty acids, and excludes modifications with styrene and rosin. The nonbenzenoid alkyd resins (maleic) class includes modifications with phenolics and oils and fatty acids and excludes modifications with styrene, phthalic alkyds, and rosin. 

Figure A. Effect of fatty acid modification on alkyd resin properties.

Modification with Other Vinyl Compounds. Low molecular mass acrylate and methacrylate esters are used to modify alkyd resins containing oil/fatty acid [2.64], [2.65], Methacrylates give products that are more interesting from the paint technol-... 

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