Paints linseed oil

Paints. Although most drying oils have been replaced as paint vehicles hy latexes and other synthetic resins, oils are still being used to a degree in paint and allied products. In exterior house paints, linseed oil or oxidizing alkyds are used when paint must be applied al temperatures as low as 4 to 5 C, i.c. temperatures at which latexes do not coalesce satisfactorily They also arc used in primers over chalky surfaces where latex paints do nol provide adequate adhesion. 

For atmospheric service, zinc dust paints (linseed oil or alkyd) continue to outperform other classes of paints, as... 

The aromatic extracts have been used in the paint industry to partially replace linseed oil. They are still used for producing printer s ink. In addition, they are finding a variety of applications as plasticizers in the rubber industry or for the manufacture of plastics such as PVC. 

Red lead is a useful ingredient of anti-rusting paints, in which it is mixed with linseed oil. If glycerol is added to this mixture, a cement suitable for luting (i.e. making airtight or watertight) joints in iron pipes or vessels is obtained. 

Chemical bleaching is never used on oils intended for edible use because it oxidizes unsaturated fatty acids to cause off-flavors. However, it does find wide usage for specialty linseed oil, for the paint industry, and fatty chemicals such as sorbitan esters of fatty acids and sodium stearoyl lactylate. Residual peroxide is destroyed by heating above its decomposition temperature. 

Table 2. Exterior Alkyd-Linseed Oil Flat Solvent-Based House Paint ...

Air oxidation of dyestuff waste streams has been accompHshed using cobalt phthalocyanine sulfonate catalysts (176). Aluminum has been colored with copper phthalocyanine sulfonate (177,178). Iron phthalocyanine can be used as a drier in wood oil and linseed oil paints (179). 

Titanates react with ester groups ki paint vehicles, eg, linseed oil, tuna oil, and alkyds, and with hydroxy groups, eg, ki caster oil and some alkyds, to prevent wrinkling of paint films (104,447). 

Cobalt in Driers for Paints, Inks, and Varnishes. The cobalt soaps, eg, the oleate, naphthenate, resinate, Hnoleate, ethyUiexanoate, synthetic tertiary neodecanoate, and tall oils, are used to accelerate the natural drying process of unsaturated oils such as linseed oil and soybean oil. These oils are esters of unsaturated fatty acids and contain acids such as oleic, linoleic, and eleostearic. On exposure to air for several days a film of the acids convert from Hquid to soHd form by oxidative polymeri2ation. The incorporation of oil-soluble cobalt salts effects this drying process in hours instead of days. Soaps of manganese, lead, cerium, and vanadium are also used as driers, but none are as effective as cobalt (see Drying). 

Many similar hydrocarbon duids such as kerosene and other paraffinic and naphthenic mineral oils and vegetable oils such as linseed oil [8001-26-17, com oil, soybean oil [8001-22-7] peanut oil, tall oil [8000-26-4] and castor oil are used as defoamers. Liquid fatty alcohols, acids and esters from other sources and poly(alkylene oxide) derivatives of oils such as ethoxylated rosin oil [68140-17-0] are also used. Organic phosphates (6), such as tributyl phosphate, are valuable defoamers and have particular utiHty in latex paint appHcations. Another important class of hydrocarbon-based defoamer is the acetylenic glycols (7), such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol which are widely used in water-based coatings, agricultural chemicals, and other areas where excellent wetting is needed. 

Soybean oil and tall oil fatty acids are not used in paints without modification. These products, Hsted as used in paints, first must be converted to alkyds or other synthetic drying oils. Presumably significant amounts of the linseed oil Hsted under paints are also converted to alkyds or other derivatives before use. In addition to the numbers given in Table 2, relatively large amounts of the oils are reported to have been consumed by conversion into fatty acids. Some indeterrninate fraction of the fatty acids, especially tall oil fatty acids, are presumably converted into derivatives that are used like drying oils. 

A frequently cited example of protection from atmospheric corrosion is the Eiffel Tower. The narrow and, for that age, thin sections required a good priming of red lead for protection against corrosion. The top coat was linseed oil with white lead, and later coatings of ochre, iron oxide, and micaceous iron oxide were added. Since its constmction the coating has been renewed several times [29]. Modern atmospheric corrosion protection uses quick-drying nitrocellulose, synthetic resins, and reaction resins (two-component mixes). The chemist Leo Baekeland discovered the synthetic material named after him, Bakelite, in 1907. Three years later the first synthetic resin (phenol formaldehyde) proved itself in a protective paint. A new materials era had dawned. 

Chemical Designations - Synonyms Flaxseed oil Raw linseed oil Chemical Formula Not applicable. Observable Characteristics - Physical State (as shipped) Liquid Color Pale yellow to dark amber Odor Like oil-base paint. 

Closely related to films are paints. Previously linseed oil, thinned with turpentine, fornted the film into which were imbedded pigments. Turpentine, from pine trees, is still used, but competes with a petroleum distillate (less smelly). Water-based latex paints are a water emulsion of an organic paint that is thinned with water. 

Lack-industrie,/. (paint and) varnish industry, -lack, m. lac lake, -lasurfarbe,/. transparent varnish color, -laus,/. lac insect, -lausfarb-stoff, m. lac dye. -leder, n. japanned leather, patent leather, -leinol, n. linseed oil for varnish. -losungsmittel, n. lacquer solvent. 

It has been established that water becomes non-corrosive after contact with paints prepared by grinding basic pigments in linseed oil it was also shown that lead and zinc linoleates, prepared by heating the oxide with linseed oil fatty acids in xylene, behave in a similar way. Later this observation was extended to the linoleates of calcium, barium and strontium". 

The pigment is the principal agent in the electrochemical control of corrosion by primers (see Section 14.3). Probably the best known anticorrosive pigment is red lead. When used in conjunction with linseed oil as the binder it gives very good primers which will perform well over relatively poorly prepared (manually abraded) steel surfaces. Present-day use of red lead (and lead pigments, generally) in paints has been drastically curtailed as a result of understandable pressure from the environmentalists. 

Paints used for protecting the bottoms of ships encounter conditions not met by structural steelwork. The corrosion of steel immersed in sea-water with an ample supply of dissolved oxygen proceeds by an electrochemical mechanism whereby excess hydroxyl ions are formed at the cathodic areas. Consequently, paints for use on steel immersed in sea-water (pH 8-0-8-2) must resist alkaline conditions, i.e. media such as linseed oil which are readily saponified must not be used. In addition, the paint films should have a high electrical resistance to impede the flow of corrosion currents between the metal and the water. Paints used on structural steelwork ashore do not meet these requirements. It should be particularly noted that the well-known structural steel priming paint, i.e. red lead in linseed oil, is not suitable for use on ships bottoms. Conventional protective paints are based on phenolic media, pitches and bitumens, but in recent years high performance paints based on the newer types of non-saponifiable resins such as epoxies. 

Polyunsaturated fats can combine easily with oxygen at the points where there is a double bond between two carbon atoms. This is why they make good antioxidants they combine with the oxygen free radicals so they don t damage other molecules. It is also how oils harden, and is thus important to painters. Oil paints made with linseed oil are almost three-quarters trilinolein. They dry to form a tough plastic film that incorporates the pigments and holds them onto the surface to be painted. 

Linolenic acid is also important industrially it is the major constituent of linseed oil (approximately 47%) which is obtained from flax. The high degree of unsaturation present in this acid makes the oil an excellent drying agent for use in paints, varnishes and inks. 

The first paints were based upon linseed oil (obtained from flax). This is an unsaturated long-chain triglyceride, which, with metal activators, crosslinks via radical pathways to form a continuous film on the substrate. Modern paints use synthetic polymers together with either a solvent or suspending medium (e.g., water), which evaporates leaving the deposited film. Exceptions are powder coatings, which require heat for completion. 

Table 5.7 Prominent peaks in the mass spectra of linseed oil (see Figure 5.15) and oil paint (see Figure 5.16a and b), and tentative attribution to compounds...

The chromatogram in Figure 7.6 shows a typical profile of an aged drying oil. It was obtained in the analysis of a reference layer of linseed oil on glass pertaining to the reference paint material collection of Opificio delle Pietre Dure (Florence, Italy), artificially aged by irradiation with a mercury lamp at 365 nm for 21 days, at a temperature of 20 °C and 80% relative humidity [9]. 

Figure 7.6 Total ion current profile of the acidic fraction of a sample from a linseed oil reference paint layer (Opificio delle Pietre Dure, Florence, Italy), after saponification and silylation of carboxylic and hydroxyl ic groups [9]...

Painting on copper leaf by Boucher. Figure 7.9 shows the TIC profile relative to the TMS derivatives of FAs from the sample [9]. The values of the parameters reported in Table 7.3 indicate that the binder was linseed oil. The FA composition shows a high content of dicarboxylic acid together with oxidation products. In this case, due to the... 

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