Water acrylic adhesives

The cure reaction of structural acrylic adhesives can be started by any of a great number of redox reactions. One commonly used redox couple is the reaction of benzoyl peroxide (BPO) with tertiary aromatic amines. Pure BPO is hazardous when dry [39]. It is susceptible to explosion from shock, friction or heat, and has an autoignition temperature of 79°C. Water is a very effective stabilizer for BPO, and so the initiator is often available as a paste or a moist solid [40], The... 

Primer 2000 (b) Thermosetting acrylic adhesives 5—10 pm Air drying in 3-5 min at room temperature Cleans and etches aluminum and stainless steel Provides improved durability to salt water... 

Among the other forms of acrylics, coatings for protecting metal and acrylic enamels for cars and appliances are available in great variety. Water emulsion acrylic paints give excellent service, both indoors and out, and acrylic adhesives are used to bond many carpeting fibers to their backing and provide nonskid properties and dimensional stability. 

Unsintered tape is used for sealing threads of pipes for water and other liquids. Pressure-sensitive tapes with silicone or acrylic adhesives are made from skived or cast PTFE films. 

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. 

The most common type of synthetic water-borne adhesives are based on vinyl acetate, and include the homopolymer, polyvinyl acetate and the copolymer with ethylene, ethylene vinyl acetate, the popular white glue. Copolymers with other monomers, such as acrylics, are increasing in use, particularly for adhesion to plastics. 

Water-based adhesives also encompass emulsion and dispersion adhesives in which polymer chains are dispersed and stabilized into tiny particles or spheres in aqueous medium with the aid of surfactants. Within this category there are low-cost poly(vinyl acetate) and acrylics, and more expensive higher-performance urethanes, which are typically made of two components. 

Poly(vinyl ester) dispersions are quantitatively more important than solid resins. Homopolymer and copolymer dispersions are used for binders in emulsion (dispersion) paints, plastic-bonded plasters, and water-thinnable adhesives. Poly(vinyl acetate) dispersions are less important than vinyl acetate copolymer dispersions. The most important comonomers of vinyl acetate are vinyl laurate, dibutyl maleate, Versatic Acid esters (VeoVa, Shell), ethylene, vinyl chloride, and butyl acrylate. Poly(vinyl propionate) and copolymers of vinyl propionate with butyl acrylate, styrene, or vinyl chloride are also marketed and used as dispersions. 

Urethanes have also been used to toughen vinyl-terminated acrylic adhesives for improved impact resistance. Thus rubber-toughened urethane acrylates [79,80], water-dispersible urethane acrylates [81], and high-temperature-performance urethane-acrylate structural adhesives have been reported [82]. Polyurethanes terminated with acrylic functionality are also used for anaerobic or radiation-cured adhesives with improved toughness [83]. 

Elastomers used in water-based systems include various rubber latices, especially natural rubber and SBR, and occasionally, polychloroprene. The bulk of the market in water-based adhesives is now held by acrylic dispersions. Although these are designed for use without modification, it is normal to formulate, especially by addition of tackifiers. Commonly used tackifying resins include soft resins, or hard resins in solution, which may... 

Uses Acrylic for pigmented or dear finishes, low-VOC finishes Features Exc. water resist., adhesion to a variety of metal and plastic substrates... 

Chem. Descrip. 3-Methaciyloxypropyl trimethoxysilane CAS 2530-85-0 EINECS/ELINCS 219-785-8 Uses Coupling agent for free-radical crosslinked polyester, rubber, polyolefins, styrenics, acrylics adhesion promoter for solv., water-based, solventless, arid powd. coating systems pigment treatment Properties Sp.gr. 1.040 vise. 2 cSt flash pt. (CC) 46 C 100% act. 

Uses Tackifier resin for water-based adhesives and sealants based on acrylic, S/B, nat. rubber, neoprene, and PVAc, esp. for pressure-sensitive adhesives, and for coatings Features Solv.-free... 

Chem. Descrip. Benzophenone 6 CAS 131-54-4 EINECS/ELINCS 205-027-3 Uses UV stabilizer for polyester film and rubber, PU coatings, furniture stains and varnishes, nitrocellulose lacquers, fluorescent pigments, photographic emulsions, dyed polyester fabrics, and acrylic adhesives Properties Pale yel. powd. insol. in water sol. < 1% In methanol, 5% in ethyl acetate, 5% in MEK, and 5% in toluene mass dens. 1.34 g/cm m.p. 130-132 C Maxgard 400 [Lycus Ltd]... 

FTIR-EGA is useful for evaluation of the effects of additives on thermal stability, and conversely can be used to distinguish between similar materials. Chlorine-containing polymers may be readily identified from their hydrogen chloride evolution profiles. Differences in formulations of the same polymer can be detected in the same way. The hydrogen chloride evolution profiles from three samples of PVC compound are shown in fig 4. One of the samples is clearly different from the other two. Confirmatory evidence is usually provided by the profiles for water, carbon dioxide and hydrocarbons. The FTIR-EGA technique has been similarly useful for characterisation of elastomers, epoxy and acrylic adhesive systems, polyurethanes, and acrylic glazing materials. The published literature on thermal degradation has provided a rich base on which to work. 

Corporation (Golden, CO). The reactor, 1.22m wide by 2.44 m, consisted of a fiberglass-reinforced plastic I-beam frame. A transparent fluoropolymer film, treated to accept adhesives, formed the front and back windows of the reactor. The film windows were attached to the reactor frame with foam tape coated on both sides with an acrylic adhesive. The catalyst, titanium dioxide (Degussa P25), was coated onto a structured, perforated polypropylene tubular packing commonly used in oil-water separators. The Ti02 was suspended in water as a slurry and sprayed onto the tubular supports with a new paint sprayer until the supports were opaque. Fluid modeling of airflow flnough the reactor showed that a 5.1 cm PVC manifold, located at the inlet and outlet of flie reactor, would provide an even flow distribution. Small (0.6 cm) holes, drilled into flie manifold at one inch intervals, provided the even flow distribution required for efficient contact of the contaminated air with the catalyst. 

Acrylonitrile-butadiene rubber, NBR, styrene-aciylonitrile rubber, SAN, ethylene-vinyl acetate copolymer, EVA, and acrylic copolymers are helpful modifications of polyvinylchloride that change its processing characteristics and elastomeric properties. Blending with these copolymers helps to reduce the requirement for low molecular weight plasticizers. Ethylene-vinyl acetate copolymer plays a role of high molecular weight plasticizer in production of vinyl hose. This reduces the amount of DOP used in flexible hose applications. Ethylene copolymer is used plasticize PVC that reduces gel. "" Phthalate plasticizers can be eliminated from water based adhesives because of utilization of vinyl acetate ethylene copolymer as a high molecular plasticizer/modifier. " ... 

There are two general types of water-based adhesives solutions and latexes.Solutions are made from materials that are soluble only in water or in alkaline water. Examples of materials that are soluble only in water include animal glue, starch, dextrin, blood albumen, methyl cellulose, and polyvinyl alcohol. Examples of materials that are soluble in alkaline water include casein, rosin, shellac, copolymers of vinyl acetate or acrylates containing carboxyl groups, and carboxymethyl cellulose. 

Phenylene oxide-based resins (Noryl ) epoxy, polyisocyanate, polyvinyl butyral, nitrile rubber, neoprene rubber, polyurethane rubber, polyvinyUdene chloride, and acrylic. Polyethylene-nitrile rubber, polyisobutylene rubber, flexible epoxy, nitrile-phenolic, and water-based (emulsion) adhesives. Polystyrene for these foams (expanded polystyrene (EPS)), aromatic solvent adhesives (e.g., toluol) can cause collapse of the foam cell walls. For this reason, it is advisable to use either 100% solids adhesives or water-based adhesives based on SBR or polyvinyl acetate. Specific adhesives recommended include urea-formaldehyde, epoxy, polyester-isocyanate, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, and reclaim rubber. Polystyrene foam can be bonded satisfactorily with any of the following general adhesive types ... 

Figure 5.30 (upper) Effect of temperature on adhesive shear behaviour (from reference 5.18). (lower) Effect of immersion in water of ERP/two-part acrylic adhesive/ERP joints on the tensile... 

---