Latex adhesives heat reactivation

Waterborne contact adhesives contain an elastomer in latex form, usually an acryflc or neoprene-based latex, and a heat-reactive, cross-linkable phenohc resin in the form of an aqueous dispersion. The phenoHc resin improves metal adhesion, green strength, and peel strength at elevated temperature. A typical formulation contains three parts latex and one part phenohc dispersion (dry weight bases). Although metal oxides may be added, reaction of the oxide with the phenohc resin does not occur readily. 

A second generation of phenolic dispersions, patented by J. S. Fry (33). involved the post dispersion of phenolic resins in a mixture of water and water-miscible solvents. To conform with air pollution regulations, the solvent was held to 20 volume %, or less, of the volatiles. A heat-reactive phenolic resin dispersion (34) and a phenolic-epoxy codispersion have become commercially available based on the above technology. Supplied at 40-45% solids, these products, which have a small particle size (0.75-1.0 ym), are better film formers than the earlier dispersions. Used alone or in blends with other waterborne materials, corrosion-resistant baking coatings may be formulated for coil coating primers, dip primers, spray primer-surfacers, and chemically resistant one-coat systems. Products of this type are also tackifiers for acrylic latexes, and such systems have been employed as contact, heat seal, and laminating adhesives for diverse substrates. 

Chem. Desaip. Aaylic latex, heat-reactive Uses Aciylic for laminating adhesives, flock adhesives, textiie finishes, nonwoven binding, paper saturation, and foam backcoatings for tex-tiies hand modifier for durable press Feataes Produces med. films Properties Sp.gr. 1.06 vise. 100 cps pH 3.7 49% solids Hycai 26084 [Noveon]... 

Chem. Descrip. Aaylic latex, heat-reactive Uses Binder for paper coatings, textile backcoatings, nonwoven saturation, leather finishes, paper saturation, adhesives Features Produces firm films washfast exc. solv. and plasticizer resist. Properties Colorless sp.gr. 1.07 vise. 110 cps pH 6.1 48% solids Hycai 26092 [Noveon]... 

Chem. Descrip. Acrylic latex, heat-reactive Uses Acrylic tor protective coatings, paper saturation, adhesives, nonwoven fabric bindings produces stiff films Properties Sp.gr. 1.05 vise. 80 cps pH 5.0 50% solids Hycai 26120 [Noveon]... 

Chem. Descrip. Acrylic latex, heat-reactive Uses Acrylic for fextile laminating adhesives, abrasion-resist, textile and paper coatings, textile sizing, paper saturation, nonwoven binders, metal coatings, textile finishing food pkg. adhesives, coatings, paper, polymers, rubber articles... 

Lamination (sticking together of layers) of fabric, foam and film, in various combinations, can be performed using latex- and solvent-based or fusible adhesives (see Adhesive classification). In addition, adhesives are sometimes applied from solution or latex for subsequent reactivation by heat during lamination. Acrylic dispersions are the main type of latex-based adhesives used in the laminating industry butadiene rubbers and polyurethanes are also utilized in smaller quantities. The latex-based adhesives are used for aesthetic reasons and also on heat-sensitive or open-structured fabrics. The solvent-based adhesives, for example rubbers and polyurethanes, are used in applications similar to those for latex adhesives. 

Latex 750 a contains medium gel, slow crystallizing polymer which gives an excellent combination of flexibility, dry tack, heat-reactivity and cohesive strength. It is used primarily in contact bond adhesives. 

Latex 735A contains a sol polymer which gives the longest dry open tack time of all the latexes. Its films are also the most readily heat reactivated. Latex 735A is generally used in adhesives for wet laminating. 

Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and fumes NFPA Health 0, Flammability 1, Reactivity 0 Uses Plasticizer for polymers, vinyl acetate resins, adhesives, latex coatings emollient, plasticizer in cosmetics in food-pkg. adhesives plasticizer for PVAc coatings for paper/paperboard in contact with aq./fatty foods plasticizer for polymers for paper/paperboard in contact with dry food Regulatory FDA 21CFR 175.105, 176.170, 176.180... 

Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and irritating fumes Uses Lubricant for two-stroke cycle engines, rubber, greases, textiles reactive intermediate for resins, plasticizers, surfactants antifoam in boiler water, latex processing solvent for inks and dyes antistat in cosmetics food-pkg. adhesives defoamer for food contact Manuf./Distrib. Aldrich http //www.sigma-aldrich.com... 

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