Pressure-sensitive latex

A unified science of adhesion is still being developed. Adhesion can result from mechanical bonding between the adhesive and adherend and/or primary and/or secondary chemical forces. Contributions through chemical forces are often more important and illustrate why nonpolar polymeric materials such as polyethylene are difficult to bond, although polycyanoacrylates are excellent adhesives. Numerous types of adhesives are available such as solvent-based, latex, pressure-sensitive, reactive, and hot-melt adhesives. 

A. D. Hickman, "The Design of S/B Latex Pressure Sensitive Adhesives," a paper presented to the TAPPI, 1983 Paper Synthetics Conference, Sept. 1983. 

Neoprene Latex Pressure Sensitive Adhesives, Tape Council (June 16, 1980), E. I. du Pont de Nemours Co., Inc., 1980. 

Gazeley. K.F. and Mente, P.G., Pressure-sensitive adhesives from modified natural rubber latex. Adhesives, Sealants and Encapsulants Conference, Kensington, London, 5th November, 1985. 

Tackifiers to produce pressure-sensitive adhesives were also prepared as a latex. Self-emulsifying resin or rosin composition, useful as tackifiers for ad-... 

At high (50—100 pph) saturation levels, with a near thermoplastic elastomer, a leather-like material results that can be embossed. The paper web used in pressure-sensitive tape is prepared by latex saturation in order to give it sufficient internal strength to release without delamination. 

Pressure-sensitive tape (Scotch tape) consisting of a coating of a solution of a blend of NR and an ester of glycerol and abietic acid (rosin) on cellophane was developed over a half century ago. More recently, NR latex and SR have been used in place of the NR solution. 

Ethylhexyl acrylate manufacture represented about 15 percent of domestic consumption of the alcohol. The acrylate is the longest chain acrylate ester produced by esterification of acrylic acid. The monomer is used in acrylic copolymers for pressure sensitive adhesives, PVC impact modifiers, and as a comonomer with vinyl acetate and vinyl chloride in latexes for paints and textiles. Growth over the next 5 years is estimated at 6 percent per year. 

The other major uses of acrylic latexes are in textile finishing (e.g., stain and wrinkle resistance), adhesives, and floor polishes and waxes. Adhesives are used in many applications, including pressure-sensitive tapes, contact adhesives, and construction adhesives for carpeting and floor tiles. Peelable labels and stamps probably got their start with the Post-it note, invented by Spencer Silver and Art Fry at 3M company many years ago. 

There are two main types of coldseal adhesive and these are based on natural latex or synthetic polymers. They differ from pressure-sensitive adhesives in that they stick only to themselves. They are applied to form dry but gummy adhesive layers on flexible plastic films or paper and can be subsequently sealed together by pressure alone to form wrappers for food items and especially for confectionery. 

First, latex polymers had to he optimized for the specific adhesion characteristics required in their primary areas of utility pressure sensitive and contact adhesives. Second, there had to he developed suitable aqueous dispersions of auxiliary ingredients most notable in this category are tackifters. Finally, there has been economic resistance on the part of those who apply the adhesives because of the greater difiiculty in evaporating water compared to organic solvents. Thus, most adhesive manufacturers have found it expedient to install solvent recovery equipment to meet air quality standards. 

This product is an ultraviolet light absorber for use in polystyrene, unsaturated polyesters, coatings, varnishes, lacquers, and coatings based on epoxy or phenolic alkyds. It is also used in pressure sensitive adhesives, polymethylacrylate (fdm or sheeting), thermoplastic rubbers, polyisoprene latex and alcohol based cosmetics. 

Use Tire carcasses and linings, especially for tractors and other outsize vehicles electric wire insulation encapsulating compounds steam hose and other mechanical rubber goods pond and reservoir sealant. Latex is used for paper coating, textile and leather finishing, adhesive formulations, air bags, tire vulcanization, self-curing cements, pressure-sensitive adhesives, tire-cord dips, sealants. 

Use Pressure-sensitive and hot-melt adhesives, bonding of paper to polyethylene, laminating adhesive, tackifier and plasticizer for coatings, heat sensitizer for rubber latex, pigment binder in textile finishing and printing inks, protective colloid in emulsions. 

Self-adhesive labels can be applied to most materials wood, plastic, metal, glass, paper and board. As the adhesives are resin-based (plasticised thermoplastics), migration problems can occur when they are applied to certain plastics (PVC, LDPE, etc.). Adhesive systems for pressure sensitive labels include latex and acrylic bases and adhesives which may be applied as a hot melt, or via a solvent, emulsion or dispersion base. Water-based adhesives are currently increasing in use. 

Stabilization of Carboxylated Styrene Butadiene (X-SBR) Latices Carboxylated SBR latices are used as adhesives in applications where durability and flexibility are desired. Some of the major uses for X-SBR latex are in tufted carpet backing, paper coatings, wall and vinyl floor tile adhesives, and pressure-sensitive adhesives. Typically, discoloration is the first measure of the degradation of an X-SBR latex. Discoloration of a dried latex film can often be related to a loss of the physical properties and subsequently, to inferior performance in an adhesive formulation. Figure 9 illustrates the effects of adding an effective antioxidant system to an X-SBR latex on the level of discoloration as a result of static oven aging at 150°C (300°F). The addition of AO-4 alone... 

Minor amounts of carboxylic acid monomers are sometimes polymerized into vinyl-acrylic latexes, chiefly for introducing a viscosity response to changes in pH. Acrylic acid (AA) is also used for the pressure-sensitive adhesive market. Gajria and Tjayendran [41] studied the pH response of AA and methaciylic acid (MAA) modified VAc/BA latexes. Feeding the acid in the monomer feed as opposed to a water solution feed produced a greater viscosity response upon pH... 

At the other end of the spectrum, pressure-sensitive adhesives, contact adhesives, aqueous varnishes, clear sealants and caulks, overprint varnishes for metal decorating and printing are essentially pigment free. Minor amounts of silica are used for gloss reduction in the case of varnishes. Carpet, construction and ceramic/brick adhesives may contain substantial amounts of filler, not only to reduce cost but also to provide shear strength. Gloss and semi-gloss latex enamels... 

Hou et al. [42] studied the effect of AA in pressure-sensitive adhesives composed of a terpolymer of 2-ethylhexyl acrylate, VAc and AA. Like Gajria et al. they noticed a dependence of latex swelling with polymerization procedure. Hou et al. noted that batch polymerized latexes produced greater viscosity responses with pH adjustments. They demonstrated that addition of sodium chloride effectively reduced the pH-thickening response curve. Hnally, Kries and Sheiman [43] studied the influence of polymerizing various fimctional monomers on the wet adhesion of VAc/B A latexes. A number of monomer types were studied, such as polymoizable monomers containing amines, amides and acetoacetates, alone and in combination with each other. The ureido functional monomras exhibited supoior wet adhesion. 

Bon, Keddy, and coworkers [109] demonstrated that soft armored polymer latex made via Pickering miniemulsion polymerization [i.e., poly(lauryl acrylate) armored with Laponite clay discs] could be used as a nanocomposite additive in standard poly(butyl acrylate-co-acrylic acid) waterborne pressure-sensitive adhesives (PSAs), leading to marked mechanical property enhancements (see Fig. 13). 

Uses Surfactant, emulsifier for latex or paper coatings, carpet backings, textiles, pressure-sensitive adhesives, esp. S/B, styrendacrylic, and acrylic emulsion polymer systems... 

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