Rubber-based solvent cements

When joining is required over the entire surface, pressure-sensitive adhesives, adhesive tape systems, or hot-melt adhesive foils can be used. For health reasons, conventional rubber-based solvent cements are used rarely today. There is a trend to replace them with hot melts or water-based adhesives. With new application techniques the hot melts can be... 

Rubber-based solvent cements are adhesives made hy combining one or more rubbers or elastomers in a solvent. These solutions are further modified with additives to improve the tack or stickiness and the degree of peel strength, flexibility, and the viscosity, or body. Rubber-based adhesive is used in a wide variety of applications, such as contact adhesive from plastic laminates used for counter tops, cabinets, desks, and tables. Adhesive is used on pressure-sensitive tapes as floor tile adhesive and carpeting adhesive. Self-sealing envelopes and shipping containers use rubber cements. Solvent-based rubber adhesives have been the mainstay of the shoe and leather industry. 

MEK also is used as the solvent in lube oil dewaxing, wood pulping, and toluene (see Chapter 3), and in the manufacture.of printing ink and rubber-based industrial cements. 

Phenolic-neoprene contact cements are used for structural metal-metal bonding. especially where fatigue resistance and low temperature performance are important [209]. They are also used for bonding textiles, wood, rubbers, plastics, ceramics, and glass to metal and to one another. Solvent toxicity and flammability has greatly reduced the use of contact cements in the wood products industry. Water-based contact cements persist, but generally do not perform as well as the solvent systems, thus allowing market erosion by alternative binders. 

Polystyrene Although polystyrene is usually bonded by solvent cementing, it can be bonded with vinyl acetate/vinyl chloride solution adhesives, acrylics, polyurethanes, unsaturated polyesters, epoxies, urea-formaldehyde, rubber-base adhesives, polyamide (Versamid-base), polymethylmethacrylate, and cyanoacrylates. The adhesives should be medium-to-heavy viscosity and room-temperature and contact-pressure curing. An excellent source is a Monsanto Company technical information bulletin which recommends particular commercial adhesives for bonding polystyrene to a number of different surfaces. Adhesives are recommended in the fast-, medium-, and slow-setting ranges (10). 

Solvent solutions and latex cements require the removal of the solvent from the adhesive before bonding can take place. This is accomplished by simple or heat-assisted evaporation. Some of the stronger or more environmentally resistant rubber-based adhesives require an elevated-temperature cure. Only slight pressure is usually required with pressure-sensitive adhesives (PSAs) to obtain a satisfactory bond. These adhesives are permanently tacky and flow under pressure, thus they provide intimate contact with the adherend surface. 

Adhesives used to bond acetal homopolymer to itself and to other materials, such as aluminum, steel, natural rubber, neoprene rubber, and Buna rubber, include polyester with isocyanate curing agent, rubber-based adhesives, phenolics, epoxies, modified epoxies, and vinyls. Solvent cementing... 

Adhesive for cellulose nitrate film on metals Cement, vinyl acetate base solvent type Adhesive, synthetic rubber (hot or cold bonding)... 

Plastic foams. Some solvent cements and solvent-containing pressure-sensitive adhesives will collapse thermoplastic foams. Water-based adhesives, based on styrene butadiene rubber (SBR) or polyvinyl acetate, and 100 percent solid adhesives are often used. Butyl, nitrile, and polyurethane adhesives are often used for flexible polyurethane foam. Epoxy adhesives offer excellent properties on rigid polyurethane foam. 

The process of masticating and dissolving natural rubber is important for pressure sensitive formulation as well as for solvent cement production. Pressure sensitive tapes and labels based on natural rubber are a significant part of the rapidly growing pressure sensitive adhesive... 

Solvent cements encompass a wide range of performance properties, from the simple natural rubber based cements which are widely used for low performance applications in homes and schools to the structural applications of contact adhesives based on polychloroprene and reactive phenolic resins. 

Rubber and cellulosic-type solvent cements are used for attaching gaskets and blotters. Water based adhesives such as sodium silicate, starch, dextrin, and latex are used for a variety of applications such as labeling. 

The adhesives industry is the third most important market for rosin. Rosin, modified rosins, and rosin derivatives are used in several types of adhesives, including the pressure-sensitive, hot-melt, and elastomer-based latices, and solvent rubber cements. 

The latexes upon which this industry developed were natural rubber and polychloroprene for solvent resistance. However, technology is advancing to permit penetration of carboxylated nitrile latex for optimized solvent resistance and tougher abrasion resistance. Among the competition to latexes in this field are poly(vinyl chloride) plastisols. As technology develops in producing small particle size latexes from polymers whose synthesis is loo water-sensitive for emulsion polymerization, the dipped goods industry will quickly convert to their utilization from the solvent-based cements of these polymers now employed Prime candidates include butyl rubber, EPDM, hypalon, and vlton. 

Acetone s primary applications are based on its ability to dissolve such a wide array of organic substances. It is used as a solvent for paints, varnishes, lacquers, inks, glues, rubber cements, fats, oils, waxes, and various types of rubber and plastics. It is perhaps best known to the average person as the primary ingredient in nail polish remover. The largest single use of the compound is as a raw material in the manufacture of other organic chemicals, such as chloroform,... 

In the context of adhesives, cement is a natural rubber- or silicone-based elastomeric. Rubber cements contain a suitable solvent such as naphtha or aromatic hydrocarbons. Pyroxylin cements are adhesives based on solutions of nitrocellulose in alcohol, ether, or another solvent. Hydraulic cements used in construction, such as portland or pozzolana cement, are nonhazardous mixtures composed of some combination of lime, alumina, and silica which sets into a hard product (concrete) when water is added (the term portland... 

Efforts to bond rubber to metal without the use of metal plating led to what is believed to be the first research efforts in surface preparation prior to adhesive bonding. Strong and durable bonds of rubber to metal were necessary for rubber shock mounts for automobiles in the late 1920s, but they were limited to proprietary formulations used on specific metals. In 1927 solvent-based thermoplastic rubber cements for metal-to-rubber bonding were prepared from rubber cyclized by treatment with sulfuric or other strong acids. With these rubber cements strong bonds could be made to either vulcanized or unvulcanized rubber. 

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