Vinyl-resin adhesives

Benzoflex [Velsicol], TM for a series of plasticizers that are dibenzoate esters of dipropylene glycol or any of several polyethylene glycols. Use Primary plasticizer for vinyl resins adhesive formulations some grades in food-packaging adhesives. 

Vinyl Resins Adhesives. The figures for adhesives separately are disclosed in the annual census of 1947 (5) and in the monthly (9) and annual tariff data (11) for... 

Uses Plasticizer for vinyl resins, adhesives in food-pkg. adhesives Regulatory EDA 21CFR 175.105 Manuf/Distrib. Salor... 

Formula C6H5C0(0CH2CH2)300CC6H5 Properties Cryst. dens. 1.168 m.p46 C b.p. 210-223 C flash pt. 236 C Precaution Combustible Uses Plasticizer for vinyl resins, adhesives in food-pkg. adhesives Regulatory FDA 21CFR 175.105 Manuf./Distrib. Salor... 

Emulsion Adhesives. The most widely used emulsion-based adhesive is that based upon poly(vinyl acetate)—poly(vinyl alcohol) copolymers formed by free-radical polymerization in an emulsion system. Poly(vinyl alcohol) is typically formed by hydrolysis of the poly(vinyl acetate). The properties of the emulsion are derived from the polymer employed in the polymerization as weU as from the system used to emulsify the polymer in water. The emulsion is stabilized by a combination of a surfactant plus a coUoid protection system. The protective coUoids are similar to those used paint (qv) to stabilize latex. For poly(vinyl acetate), the protective coUoids are isolated from natural gums and ceUulosic resins (carboxymethylceUulose or hydroxyethjdceUulose). The hydroHzed polymer may also be used. The physical properties of the poly(vinyl acetate) polymer can be modified by changing the co-monomer used in the polymerization. Any material which is free-radically active and participates in an emulsion polymerization can be employed. Plasticizers (qv), tackifiers, viscosity modifiers, solvents (added to coalesce the emulsion particles), fillers, humectants, and other materials are often added to the adhesive to meet specifications for the intended appHcation. Because the presence of foam in the bond line could decrease performance of the adhesion joint, agents that control the amount of air entrapped in an adhesive bond must be added. Biocides are also necessary many of the materials that are used to stabilize poly(vinyl acetate) emulsions are natural products. Poly(vinyl acetate) adhesives known as "white glue" or "carpenter s glue" are available under a number of different trade names. AppHcations are found mosdy in the area of adhesion to paper and wood (see Vinyl polymers). 

Pentaerythritol in rosin ester form is used in hot-melt adhesive formulations, especially ethylene—vinyl acetate (EVA) copolymers, as a tackifier. Polyethers of pentaerythritol or trim ethyl ol eth an e are also used in EVA and polyurethane adhesives, which exhibit excellent bond strength and water resistance. The adhesives maybe available as EVA melts or dispersions (90,91) or as thixotropic, one-package, curable polyurethanes (92). Pentaerythritol spko ortho esters have been used in epoxy resin adhesives (93). The EVA adhesives are especially suitable for cellulose (paper, etc) bonding. 

Usage of phosphoms-based flame retardants for 1994 in the United States has been projected to be 150 million (168). The largest volume use maybe in plasticized vinyl. Other use areas for phosphoms flame retardants are flexible urethane foams, polyester resins and other thermoset resins, adhesives, textiles, polycarbonate—ABS blends, and some other thermoplastics. Development efforts are well advanced to find appHcations for phosphoms flame retardants, especially ammonium polyphosphate combinations, in polyolefins, and red phosphoms in nylons. Interest is strong in finding phosphoms-based alternatives to those halogen-containing systems which have encountered environmental opposition, especially in Europe. 

Vinyl resins ie, copolymers of vinyl chloride and vinyl acetate which contain hydroxyl groups from the partial hydrolysis of vinyl acetate and/or carboxyl groups, eg, from copolymerized maleic anhydride, may be formulated with alkyd resins to improve their appHcation properties and adhesion. The blends are primarily used in making marine top-coat paints. 

Vinyls. Vinyl resins are thermoplastic polymers made principally from vinyl chloride other monomers such as vinyl acetate or maleic anhydride are copolymerized to add solubUity, adhesion, or other desirable properties (see Maleic anhydride, maleic acid, and fumaric acid). Because of the high, from 4,000 to 35,000, molecular weights large proportions of strong solvents are needed to achieve appHcation viscosities. Whereas vinyls are one of the finest high performance systems for steel, many vinyl coatings do not conform to VOC requirements (see Vinyl polymers). 

At the same time, natural adhesives such as casein glues, animal glue and polysaccharide gums have gradually been replaced by synthetic adhesives vinyl thermoplastic adhesives [poly(vinyl acetate)], adhesives obtained by reticulation in situ of two components (as epoxy resins), represent very important materials in this field. 

The first synthetic polymers to be used as paint varnishes were acrylic and vinylic resins. Poly(vinyl acetate) (PVAc), commercialized under the name Mowilith by Hoechst and Vinylite by Union Carbide, has been used in conservation as an adhesive since 1932 and in 1937 it was proposed as a picture varnish by Stout and Cross [63]. PVAc was soon rejected as a varnish because, despite its light stability and good solubility in organic solvents, it demonstrated poor optical properties in terms of colour saturation and the tendency to pick up dirt due to its low glass transition temperature. 

Uses Solvent for cellulose acetate, crude rubber, natural resins, nitrocellulose, vinyl resins, waxes, fats, oils, shellac, rubber, DDT, and other pesticides preparation of adipic acid and caprolactum additive in wood stains, paint, PVC paints, lacquers (to prevent blushing or improve flow), and varnish removers degreasing of metals spot remover lube oil additive in PVC adhesives to control evaporation rate leveling agent in dyeing and delustering silk. 

Anhydride modified ethylene promoter (20) vinyl acetate resin, adhesion... 

Other copolymers of this type with vinyl acetate or vinyl butyral resins have been found satisfactory for use in the lamination of wood, glass and metals. Glass-resin adhesives are also known. 

Coumarone-indene resins are sold under various trade names Cumar, Neville, Nevindene, Paradene Picoumaron. Numerous applications in industry include uses in plastics, protective coatings, adhesives, lacquers, and as plasticizers for cellulose esters vinyl resins Refs i) Beil 17, 56 [ 57.1 2) Kirk Othmer... 

Epoxy resins may be blended with certain vinyl polymers to improve the impact strength and peel strength of the adhesive. Polyvinyl acetals, such as polyvinyl butyral and polyvinyl formal, and polyvinyl esters are compatible with DGEBA epoxy resins when added at concentrations of 10 to 20% by weight. The addition improves the resulting impact resistance and peel strength of the cured adhesive. However, temperature and chemical resistance are sacrificed by the addition of the low-glass-transition-temperature vinyl resins. 

Epoxidized oils such as soybean oil or linseed oil, which are made by oxidizing the internal unsaturation in the fatty acid chain, find much use as plasticizers, particularly in vinyl resins. An internal epoxy ring is much less reactive than a terminal epoxy ring and usually does not take part in typical epoxy curing reactions under mild conditions. These materials can be used as plasticizers in epoxy adhesives but cannot really be considered reactive diluents. 

Vinyl resins are widely used as fabric coatings because of their combination of toughness and flexibility, and their property of not supporting combustion. Because they are nonflammable they replaced nitrocellulose lacquers for many applications on fabrics. They produce excellent coatings on metals but care must be taken in their application because, like most high polymers, they have strong cohesive forces that may overcome the adhesive forces. The entire coating may flake off as a continuous sheet if the precise application conditions have not been complied with for the various modifications. 

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