Oil modified alkyds

Low viscosity cellulose propionate butyrate esters containing 3—5% butyryl, 40—50% propionyl, and 2—3% hydroxyl groups have excellent compatibihty with oil-modified alkyd resins (qv) and are used in wood furniture coatings (155). Acetate butyrate esters have been used in such varied apphcations as hot-melt adhesive formulations (156), electrostatically spray-coated powders for fusible, non-cratering coatings on metal surfaces (157—159), contact lenses (qv) with improved oxygen permeabiUty and excellent wear characteristics (160—162), and as reverse-osmosis membranes for desalination of water (163). 

High phenyl content resins are compatible with organic resins of the P-F, U-F, M-F, epoxy-ester and oil-modified alkyd types but are not compatible with non-modified alkyds. Silicone resins are highly water repellent. 

Oil-base (including oil-modified alkyd resin) paint films should not be used in alkaline environments as the paint will deteriorate owing to saponification alkali-resistant coatings are provided by some cellulose ethers, e.g. ethyl cellulose, certain polyurethane, chlorinated rubber, epoxy, p.v.c./ p.v.a. copolymer, or acrylic-resin-based paints. In particular, aluminium and its alloys should be protected by alkali-resistant coatings owing to the detrimental effects of alkali on these metals. 

From these, prepolymers are prepared where the diisocyanates may be completely reacted as in the case of the urethane oils which resemble the oil-modified alkyds but have urethane (—NHCOO—) links in place of the ester (—COO—) links of the alkyds, or where one only of the isocyanate groups is combined, leaving the other to participate in crosslinking reactions. Such a reactive prepolymer is the biuret that may be prepared from hexamethylene diisocyanate, has the following structure ... 

Duraplex. Trademark of Rohm Haas Co for drying and nondrying oil-modified alkyd resins derived from phthalic anhydride, poly-hydric alcohols, and vegetable oils (Ref 2). 

Both aqueous polymer-based systems (latex), made by emulsion or dispersion polymerization, and oil-modified alkyd resin-based systems are still in wide use [781], Table 12.2 shows the composition of a typical water-based emulsion paint. There is a wide variety of coatings, ranging from broad applicability to highly specialized, including latexes, amino resins, isocyanates, epoxy resins, acrylic resins, polyester... 

Duraplex. Trademark of Rohm Haas Co for drying and nondrying oil-modified alkyd resins derived from phthalic anhydride, poly-hydric alcohols, and vegetable oils (Ref 2). It was used by Aerojet Engineering Corp, Azuza, Calif as an ingredient of some solid propellants, such as RL-223 (Ref 1)... 

This process involves both direct esterification and trans-esterification reactions, and is carried to a sufficient extent of reaction to give a viscous liquid product, an oil-modified alkyd. 

The use of oil-modified alkyds with nitrocellulose in lacquers is perhaps the first "polymeric merger" that resulted in the remarkable growth in the use of nitrocellulose lacquers. Compatibility of alkyds with nitrocellulose extends up to about 50%... 

As noted earlier, oil-modified alkyds contain free hydroxyl groups, and these groups represent sites for reaction with polyisocyanates. The resultant products possess faster drying, better chemical resistance, and abrasion resistance. Rosin is frequently used in a monobasic acid modifier to replace a portion of the oil fatty acids. As such, it promotes hardness, fast set, and solubility but impairs color, color retention, and durability, depending on the quantity used. Small amounts (up to 5%) improve the solubility without detracting from other properties to any significant degree. 

USE Food and salad oil, in candy manuf, in oleomargarine. Like wheat germ oil in dietary supplements. Industrially in oil -modified alkyd resins and soap manuf. 

The degree of unsaturation in these oil-modified alkyds was controlled by the amount and type of unsaturated acid used in the formation of the polyester. These unsaturated polymers cured or "dried" through auto-oxldatlon by oxygen from the air which reacted with the unsaturated carbon atoms on the surface of the freshly deposited film. This crosslinking reaction, like that of the "drying" of oil-based paints, was catalyzed by heavy metal salts, such as lead or cobalt salts of organic acids. Alkyds, which are some of the most Important paint resins, are produced at an annual rate in excess of 300 thousand tons. 

The solvency of cycloaliphatic hydrocarbons is between that of aliphatic and aromatic hydrocarbons. They have a high solvency for fats, oils, oil-modified alkyd resins, styrene-modified oils and alkyd resins, bitumen, rubber, and other polymers. Polar resins (e.g., urea-, melamine-, and phenol-formaldehyde resins), as well as alcohol-soluble synthetic resins and cellulose esters are, however, insoluble. 

Compared to aliphatic hydrocarbons, aromatic hydrocarbons (DIN 51633) have a higher solvency for oils, castor oil, oil-modified alkyd resins, styrene-modfied oils and alkyd resins, saturated polyester resins, polystyrene, poly(vinyl ethers), polyacrylate and polymethacrylate esters. poly(vinyl acetate), vinyl chloride and vinyl acetate copolymers, and many low-polarity resins. 

Methanol[67-56-l] (methyl alcohol) is a clear, colorless liquid with a characteristic odor. It is hygroscopic and miscible in all proportions with water as well as with many organic solvents. It is less soluble in fats and oils, and is only partially miscible with aliphatic hydrocarbons. Numerous inorganic substances (e.g., many salts) are soluble in methanol. Methanol has a good solvency for polar resins, cellulose nitrate, and ethyl cellulose. However, oil-modified alkyd resins and polymers, with the exception of poly(vinyl acetate), poly(vinyl ethers), polyvinylpyrolidone and polymethacrylamide, are insoluble. 

A. 1. Aigbodion, C. K. S. Pillai, I. O. Bakare and L. E. Yahaya, Synthesis, characterisation and evaluation of heated rubber seed oil and rubber seed oil-modified alkyd resins as binders in surface coatings , Ind J Chem Technol, 2001, 8,378-84. 

P. Sabin, B. Benjelloun-Mlayah and M. Delrnas, Offset printing inks based on rapeseed and sunflower oil. Part I Synthesis and characterisation of rapeseed oil- and sunflower oil-modified alkyd resins , J Am Oil Chem Soc, 1997, 74, 481-9. 

Arriving now at current practice, the oil is chemically incorporated as a component of a polyester resin, known as an alkyd resin or sometimes as an oil-modified alkyd resin. 

Internally plasticized n. When a product is synthesized from a reaction involving two or more raw materials, it may be said to be internally plasticized if one of the raw materials is able to confer plasticity or flexibility to it. In other words, the product is plasticized because it is build up from a component, which is naturally plastic. For example, an oil-modified alkyd, in which phthalic anhydride and glycerol are combined with drying oil fatty acids, is internally plasticized by reason of the presence of the fatty acid component. If a Congo varnish were made by interaction of run Congo and linseed oil monoglyceride, it could be described as internally plasticized, in contrast to a varnish made by simple dissolution of run Congo in linseed oil, which would be externally plasticized. Also a polyvinyl acetate-acrylic co-polymer is internally plasticized while a polyvinyl acetate homopolymer, into which a plasticizer has been stirred, is externally plasticized. 

Internal plasticizer ru An agent incorporated in, or co-polymerized with, a resin dming its polymerization to make it softer and more flexible, as opposed to a plasticizer added to the resin during compounding. Common examples occur in oil-modified alkyds, and such materials have considerable practical advantages over externally plasticized systems, where the plasticizer may be lost by evaporation or leached out by water or other agents. 

Resin emulsion paint n. A water paint consisting of a water emulsion of an oil-modified alkyd or other resin when dry, leaves a tough film of resin. 

A urethane alkyd is an alkyd in which some of the dibasic acid is replaced by diisocyanate. The ester links are formed first in the usual way, the diisocyanate is added and the remaining hydroxyls are reacted at 80-95 °C to form the urethane linkages (p. 223). It can be seen that the urethane alkyd shares the features of the urethane oil and the oil-modified alkyd. 

---