Polyvinyl acetate adhesives

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. 

Today about 2 000 000 tons of emulsion polymers (dry weight) are used per year worldwide for adhesives. Polyvinyl acetate and ethylene/vinyl acetate copolymers are the biggest volume (ca. 900 000 tons), mainly used in packaging and as wood glue. Polyacrylate emulsion polymers (acrylics) are second in volume (ca. 550 000 tons) and mainly used for PSAs. The demand for SB dispersions used for adhesives is about 350 000 tons per year (Ita, 2002). 

Any PVA adhesive Polyvinyl acetate emulsion or white glue. ... 

Prepared generally by ester interchange from polyvinylacelate (ethanoate) using methanol and base also formed by hydrolysis of the acetate by NaOH and water. The properties of the poly(vinyl alcohol) depend upon the structure of the original polyvinyl acetate. Forms copolymers. Used as a size in the textile industry, in aqueous adhesives, in the production of polyvinyl acetates (e.g. butynal) for safety glasses. U.S. production 1980... 

Four other groups of synthetic adhesives find uses in secondary processing, ie, overlaying, assembly gluing, etc, and in furniture and cabinet manufacture. Poly(vinyl acetate) (PVA) adhesives are widely used in appHcation of veneers and other overlays to panel substrates and in some unit-assembly operations. PVA adhesives are an emulsion of polyvinyl acetate in water and cure by loss of water. The PVA adhesives are somewhat... 

Lucie, S., Kovacevic, V., Packham, D.E., Bogner, A., Gerzina, A., Stearate-modified calcium carbonate fillers and their effect on the properties of polyvinyl acetate, composites. Proc. 2nd Int. Symp. Polymer Surface Modification Relevance to Adhesion, Newark, NJ, 24-26 May, 1999. 

Nitrile rubber adhesives. The main application corresponds to laminating adhesives. PVC, polyvinyl acetate and other polymeric films can be laminated to several metals, including aluminium and brass, by using NBR adhesives. NBR adhesives can also be used to join medium-to-high polarity rubbers to polyamide substrates. The adhesive properties of NBR rubbers can be further improved by chemical modification using polyisocyanate or by grafting with methyl methacrylate. 

More than 65% of the acetic acid produced in the United States goes into vinyl acetate. Nearly all the vinyl acetate ends up as polyvinyl acetate, used to make plastics, latex paints, and adhesives. About 12% of acetic acid is converted to acetic anhydride that is mostly used to make cellulose acetate, the white stuff in cigarette filters. It is also used in the manufacture of plastic sheeting and film and in formulating lacquers. 

Uses In polyvinyl acetate to improve fiber-tear properties plasticizer for polystyrene in epoxy resins and polyvinyl acetate to improve adhesion and resistance to chemical attack 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). 

At a concentration of 5 to 25 wt %, increased the effective kill-life of the lindane spray up to 10 times. May have been used in chlordane and BHC insecticide formulations. In polyvinyl acetate emsulsions to impart strong bonding power in adhesives (Monsanto, 1960). 

Uses Manufacture of polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride-acetate resins used particularly in latex paint paper coatings adhesives textile finishing safety glass interlayers. 

The most widely used polyvinyl acetal is polyvinyl butyrai (PVB). This transparent amorphous plastic is used as a plasticized polymer in the inner lining of safety windshield glass (Saflex). Because of the presence of hydroxyl groups, the commercial product, which is produced from 75% hydrolyzed PVAc, has a Tg of about 49 C and has excellent adhesion to glass. 

Acetic acid is an important industrial chemical. The reaction of acetic acid with hydroxyl-containing compounds, especially alcohols, results in the formation of acetate esters. The largest use of acetic acid is in the production ofvinyl acetate (Figure 1.1). Vinyl acetate can be produced through the reaction of acetylene and acetic acid. It is also produced from ethylene and acetic acid. Vinyl acetate is polymerized into polyvinyl acetate (PVA), which is used in the production of fibers, films, adhesives, and latex paints. 

Heat-setting resins cannot be plasticized by low molecular weight plasticizers. Polyvinyl acetals have been claimed for these products. American Cyanamid Co. has suggested polyvinyl acetals or butyrals in an amount of 10 to 25% of the resin for urea and melamine resins. For varnishes and adhesives, combinations of phenolic resins and polyvinyl formal are recommended. Polyvinyl acetals with higher alkyl radicals are suitable for cellulose esters and improve elasticity as well as resistance against water. 

Uses Mostly in bombs (Ref 35, pp 48-50) Another Comp B type mixt consisted of RDX 57.0, TNT 38.0, wax (Stanolind or Aristowax, mp 170-175°F) 4.8 polyvinyl acetate/resin adhesive 0.2%. In prepn of this expl mixt, the wax was emulsified in TNT by polyvinyl acetate/resin adhesive. The expl props of this compn are somewhat similar to the above mixtures, but it was not considered suitable due to the instability of the wax/TNT emulsion on standing (Ref 14)... 

Poly(butyral-co-vinyl acetate-co-vinyl alcohol) - A terpolymer with greater water resistance than polyvinyl acetate, but good adhesion to tissue when applied in ethanol solution. 

Lumber banding consists of gluing lumber strips, 1/2 to 2 inches in width, on the particleboard edges. These strips are normally used in applications where the particleboard is to be covered with wood veneers. The solid wood strip can be machined to decorative edges and, with the veneer surfaces, the panel is fully as functional and attractive as a solid wood panel, but at a lower cost. The lumber bands are normally bonded to the particleboard with polyvinyl acetate or urea-formaldehyde adhesives, cured rapidly by either contact or high frequency heating. 

Many epoxy dispersions are compatible with most types of latex emulsions including acrylic, urethane, styrene butadiene, vinyl chloride, and polyvinyl acetate. The epoxy dispersion can be used as a modifier for these emulsions to alter handling and application characteristics such as emulsion rheology, foaming tendencies, pH sensitivity, wetting properties, and coating coalescence. They can also be reacted into the latex resin either by reacting the epoxy with a functionalized latex or by use of an epoxy with a coreactant. In this way adhesive systems can be formulated that are cured at room or elevated temperatures. 

The major synthetic adhesives used for bonding wood include urea, phenol, and melamine formaldehyde resorcinol formaldehyde, phenol resorcinol, and polyvinyl acetate emulsions. More recently one-component, moisture cured polyurethane adhesives have become popular for bonding wood. Natural adhesives such as casein and animal glues are also often used for general-purpose wood bonding. Epoxies have been used for certain specialized wood joining applications such as when wood is bonded to metal substrates. 

D 4317 Specification for Polyvinyl Acetate Based Emulsion Adhesives... 

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