Waterborne adhesives

Uses Defoamer for aq. coatings, inks and adhesives, waterborne OEM, architecturai and maintenance tinishes, appiiance/metai turniture topcoats, traffic paints, anticorrosive primers, piastic dear coats, marine topcoats, wood furniture coatings... 

Chem. Descrip. Polyethylene wax emulsion CAS 9002-88-4 EINECS/ELINCS 200-815-3 Uses Antiblocking agent, slip agent, water resist, aid in adhesives, food pkg. adhesives, waterborne architectural coatings, latex applies., inks Regulatory FDA 21CFR 175.105... 

Uses Defoamer for latex, adhesives, waterborne architectural coalings, printing inks, monomer stripping and degassing, food-contact coatings/ paper food pkg. adhesives, cellophane Features High compatibility... 

Uses Stabilizer for natural and syn. latexes during mbber compding., storage, and applic stabilizer for printing inks, adhesives, waterborne architectural coalings food pkg. adhesives defoamer in food-contact paper coatings... 

Uses Associative thickener, rheology modifier for industrial latex paints, adhesives, waterborne architectural coatings, printing inks, suitable for acrylics, PVC/PVdC, PU Features Maximizes high sheer vise. 

Chem. Descrip. Tris-[3-(trimethoxysilyl)propy0 isocyanurate CAS 26115-70-8 EINECS/ELINCS 247-465-8 Uses Adhesion promoter, crosslinking agent for substrate/matrix resin combinations incl. silicone RTV adhesives, waterborne latex coatings... 

Uses Waterborne tackifierfor pressure-sensitive adhesives incl. food-pkg. adhesives, waterborne labels, decals, shelf liners, construction adhesives, tapes for carboxylated SBR, 2-ethylhexyl acrylate, butyl acrylic, SBR, NR, neoprene, VAE, urethanes defoamer in food-contact paper/paperboard waterborne for environmentally friendly adhesives... 

Chem. Descrip. Proprietary multi-hydrophobe blend Uses Defoamer for adhesives, waterborne industrial coatings, epoxy coatings, latex, acrylics, food-contact paper coatings food-pkg. adhesives Regulatory FDA 21CFR 175.105,176.200... 

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. 

Because most latices have low viscosities by compounding, most of the waterborne rubber adhesives are sprayable. Thickeners such as fumed silicas can be added to increase viscosity and thixotropy. This means that even at relatively large viscosities (over 10 Pas) many water-based rubber adhesives can be sprayed. Dip and curtain applications require viscosities between 0.05 and 0.3 Pas, whereas brush application works with viscosities between 1 and 50 Pa s. 

Crystalline polyesters are highly important as adhesive raw materials. They are normally crystalline waxes and are highly symmetrical in nature, which can aid the crystallization process [26]. Poly(hexamethylene adipate) and poly(caprolactone), shown in Table 2, are only two of the many crystallizable backbones. Poly(ethylene adipate) and poly(letramethylene adipate) are also commonly used in urethane adhesives. The crystalline polyesters are used in curing hot melts, waterborne polyurethanes, thermoplastic polyurethanes, and solvent-borne urethane adhesives. The adipates are available mostly as diols. The poly(caprolactones) are available as diols and triols. 

Polyurethane dispersions (PUD s) are usually high-performance adhesives based on crystalline, hydrophobic polyester polyols, such as hexamethylene adipate, and aliphatic diisocyanates, such as methylene bis(cyclohexyl isocyanate) (H12MDI) or isophorone diisocyanate (IPDI). These PUD s are at the more expensive end of the waterborne adhesive market but provide excellent performance. 

One-component waterborne urethanes are used as packaging adhesives and tie coats and for automotive bonding of PVC. 

Fig. 5 shows the details of bonding of the two substrates by a waterborne PUD adhesive. The figure shown assumes a PUD adhesive with a fast crystallizing backbone [59]. 

One interesting advantage of the one-component waterborne adhesives is that many are re-positionable. For example, if, for some reason, the two substrates are poorly aligned when the bonding occurs, this problem can be corrected by heating the bonded substrates above the bond activation temperature. The two substrates... 

The crystallization kinetics defines the open time of the bond. For automated industrial processes, a fast crystallizing backbone, such as hexamethylene adipate, is often highly desirable. Once the bond line cools, crystallization can occur in less than 2 min. Thus, minimal time is needed to hold or clamp the substrates until fixturing strength is achieved. For specialty or non-automated processes, the PUD backbone might be based on a polyester polyol with slow crystallization kinetics. This gives the adhesive end user additional open time, after the adhesive has been activated, in which to make the bond. The crystallization kinetics for various waterborne dispersions were determined by Dormish and Witowski by following the Shore hardness. Open times of up to 40 min were measured [60]. 

Two-component waterborne urethanes are the preferred choice to replace solvent-borne urethane adhesives, especially in the packaging and shoe industries. At this time, the packaging area is the largest application of two-part waterborne urethanes. Good strides have been made by the two-part waterborne urethanes in the shoe industry, especially in the athletic shoe market. Waterborne urethanes are also replacing the solvent-borne products in the OEM door panels. 

The two-component waterborne urethanes are similar in nature to the one-component waterborne urethanes. In fact, many one-component PUD s may benefit from the addition of a crosslinker. The two-component urethanes may have higher levels of carboxylic acid salt stabilizer built into the backbone than is actually needed to stabilize the urethane in water. As a result, if these two-component urethane dispersions were to be used as one-component adhesives by themselves (without crosslinker), they would show very poor moisture resistance. When these two-component urethane dispersions are used in conjunction with the crosslinkers listed in Fig. 8, the crosslinkers will react with the carboxylic pendant groups built into the urethane, as previously shown in the one-component waterborne urethane section. This accomplishes two tasks at the same time (1) when the crosslinker reacts with the carboxylic acid salt, it eliminates much of the hydrophilicity associated with urethane dispersion, and (2) it crosslinks the dispersion, which imparts solvent and moisture resistance to the urethane adhesive (see phase V in Fig. 5). As a result of crosslinking, the physical properties may be modified. For example, the results may be an increase in tensile properties and a decrease in elongation. Depending upon the level of crosslinking, the dispersion may lose the ability to be repositionable. (Many of the one-component PUD s may... 

Almost all urethane materials are synthesized without the use of solvents or water as diluents or earners and are referred to as being 100% solids. This is true of all foams and elastomers. There are many products, however, which do utilize solvents or water, and these are known as solvent-borne and waterborne systems, respectively. In the past, many coatings, adhesives, and binders were formulated using a solvent to reduce viscosity and/or ease application. However, the use of volatile solvents has been dramatically curtailed in favor of more environmentally friendly water (see Section 4.1.3), and now there are many aqueous coatings, adhesives, and associated raw materials. Hydrophilic raw materials capable of being dispersed in water are called water reducible (or water dispersible), meaning they are sufficiently hydrophilic so as to be readily emulsified in water to form stable colloidal dispersions. 

Turner, S. Richard, 1 Two-component (2-K), nonsagging, polyurea structural adhesive, preparation of, 255-256 Two-component (2-K) systems, 238-241 Two-component (2-K) waterborne polyurethane coatings, 206 preparation of, 254-255 Two-shot cast elastomer, preparation of, 249-250... 

Acidification of chloramine T with sulfuric acid produces the formation of dichloramine T (DCT) and hypochlorous acid (HCIO), species which react with C=C bonds of the butadiene units. The effectiveness of the treatment is ascribed to the introduction of chlorine and oxygen moieties on the mbber surface. A decrease in the pH of the chloramine T aqueous solutions produced more extended surface modifications and improved adhesion properties in the joints produced with waterborne polyurethane adhesive (Figure 27.9). The adhesive strength obtained is slightly lower than that obtained for the rubber treated with 3 wt% TCI/MEK, and its increases as the pH of the chloramine T solution decreases (Figure 27.9). A cohesive failure in the rubber is generally obtained. 

Water-based inks, 14 326 Water-based muds, 9 3-5 Water-based writing inks, 14 328 Water-borne adhesives, 25 475 Waterborne alkyds, 2 156-158 Waterborne automotive coatings, 10 448 Waterborne can coating system, 10 445-446... 

Waterborne coatings, 7 127-128, 10 443 Waterborne coating technologies, 10 349 Waterborne contact adhesives, phenolic resins in, 18 784 Waterborne polyamides, 10 400 Water-borne polyurethane coatings,... 

Dearborn, Mi., 26th-29th Oct. 1997, p.397-423 EPA AND FDA REGULATIONS AS FACTORS IN THE CONVERSION FROM SOLVENT TO WATERBORNE ADHESIVE SYSTEMS FOR FLEXIBLE PACKAGING Simmons R A Keller Heckman LLP (Adhesive Sealant Council)... 

This paper discusses how tightening environmental regulations in the USA are encouraging a shift from solvent-based to waterborne adhesives for use in flexible packaging applications. It also looks at how new adhesive systems have a relatively easy path to Food Drug Administration clearance for food packaging uses. 

Applications used in waterborne coatings and adhesives, film modifications, high-performance coatings, and inkjet technology... 

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