Varnish formulations

Ka.un. This fossil resin, classified as a copal, is found in the South Pacific, primarily in New Zealand. It formerly was used in protective coatings. It is still used in the Kauri-butanol test (ASTM D1133) to determine the volume of thinner that can be added to a varnish formulation without causing turbidity. 

A number of solid acrylic resins, all known under the commercial name of Paraloid, are used in art conservation, dissolved in organic solvents, as consolidants, coatings, or in varnish formulations these resins are generally copolymers formed by two acrylic/ methacrylic monomers [82], Paraloid B-72 is the most widely used acrylic resin in conservation, and is formed by a methyl acrylate/ethyl methacrylate (MA/EMA) copolymer with molar composition 70/30. 

Epoxy acrylates, 10 382-383 in varnish formulations, 10 442 Epoxy activation, in microarray fabrication, 16 385... 

Uses Secondary plasticizer for polyvinyl chloride in polyester resins to increase strength of fiberglass varnish formulations to improve water and alkali resistance as an insulator fluid for electric condensers and as an additive in very high pressure lubricants. In fluorescent and high-intensity discharge ballasts manufactured prior to 1979 (U.S. EPA, 1998). 

After the successful synthesis of a poly(ester-imide) and its use as wire enamel [1], a development of this class of polymers started which is not yet finished today. The progress in chemistry has been reviewed in several papers [2, 3] where general principles were described. The economical importance of poly ester-imide)s made companies uncommunicative and publication work was directed to patent applications. A large number of patents are known on poly(es-ter-imide)s. They cover various areas ranging from raw materials, resin compositions, synthesis and varnish formulations, to uses and processing. 

Additives used in formulations have the purpose of improving the flow of the enamel, to improve the thermo-mechanical properties like heat shock, or to give better adhesion of the cured film to the copper surface. Some of the additives have multiple effects. Because these effects are very specific to a given poly(ester-imide) resin and varnish formulation, the product classes are here only enumerated. Phenolics [112,113], epoxies [114,115], and silicones [116] are well known and some of them were claimed. Better understood is the effect of the phenol... 

AM 8, and AM 9 were evaluated in an overprint varnish formulation for high speed litho applications. The viscosities of the formulations were measured with a Brookfield RVT viscometer. Curing was done with an RPC UV processor with two 200 watt/inch medium pressure Hg vapor lamps or with a Fusion Systems processor with one 300 watt/inch H bulb. 

Viscosities of overprint varnish formulations containing AM or epoxy acrylate are shown in Table 3. Viscosities of the AM formulations are in the same range as that of the epoxy acrylate. 

Table 3. Overprint varnish formulations containing AM or epoxy acrylate...

Table 5. Cured film properties for the overprint varnish formulations...

Chem. Descrip. Glyceryl propoxylate triacrylate Uses Used in radiation-curable ink and varnish formulations incl. wood varnishes and sealers, vinyl, metal deco Features Exhibits fast cure and good water balance props, in wet offset litho inks produces films of relatively high crosslink dens. 

Chem. Descrip. Cl 4 fatty acid triglyceride Uses Compressing aid in tableting technical substances hydrophobing agent against moisture lubricant for machinery, lacquer and varnish formulations additive to liq. lubricating systems Properties Powd. neutral odor and taste dens. 8.73 g/cm (80 C) vise. 

It has not been feasible to identify the compositions of individual Soviet paint and varnish formulations. The following tabulation, however, shows the general types of coating materials identified by code letters in this chapter. 

Flat varnish n. Varnish formulated with a flatting agent so a to dry with a dull finish (not to be confused with a flatting or rubbing varnish). Syn matte varnish. 

Ethylcelluloses are low density polymers (1070-1180 kg.m ) with solubilities depending on the degree of ethylation usually commercial grade contains 44-48% ethoxyl functional groups. Solid masses of ethylcellulose exhibit low absorption of moisture, excellent dimensional stability and low temperature toughness and impact resistance. Chemically they are less resistant towards acids than cellulose esters but much more resistant to alkalis. They can be processed by injection molding. Because ethylcellulose is soluble in a wide variety of solvents, it provides a wide variety of varnish formulations. Benzylcelluloses yield plastics with excellent dielectric properties and chemical stability. 

Lank, H. (1976). Picture varnishes formulated with resin MS2A. In N. Brommelle, P. Smith (Eds.), Conservation and restoration of pictorial art (pp. 148-149). Butterworths. 

As noted previously, the major use of turpentine at one time was as a solvent, particularly in varnish formulations, and as a thinner for linseed-oil-base paints. Petroleum-based solvents have now replaced turpentine for these purposes. However, turpentine or turpentine fractions are packaged in small containers (up to 1 gallon) for the retail market for home use as paint thinners (including use with artist s oil paints) and as a general-purpose solvent. Turpentine fractionation products may recover some of the historical solvent use by replacing chlorofluoro-carbons in the specialized circuit board cleaning market (1). 

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