Coatings polyurethane dispersion

Thickener to a 4 mm Ford cup viscosity of 16-18 s Top coat Polyurethane dispersion (35 %) 500 parts... 

Nasrullah MJ, Bahr JA, G lagher-Lein C, Webster DC, Roesler RR, Schmitt P (2009) Automated parallel polyurethane dispersion synthesis and characterization J Coatings Tech Res 6 1-10... 

The coating is applied by traditional trade practices, namely, using rubber squeegees and paint rollers. The applied coating is cured by a mobile curing unit, which consists of a cart housing power supply for the UV lamp (see Figure 111)T If the concrete is porous, a seal coat should be applied (aqueous UV curable polyurethane dispersion (PUD) is recommended). 

Polyurethane dispersion for textile coatings, imparting extremely good softness dry cleaning and washing resistant. 

Polyurethane dispersion for finishing and coating, can be coagulated with acids or cationics. 

The growing commercial use of polymer colloids whose preparation involves step polymerisations, hybrid systems and/or new routes to dispersion of polymers has not yet spawned an equivalent level of activity in academic studies. The success of the Avecia ex Zeneca Resins) technology for preparation of polyurethane dispersions is a good example of the importance of such developments. There also is the attraction of using conventional solvent-borne coating vehicles e.g., alkyd resins) in aqueous media and hybrid systems... 

Howarth, G.A. and Manok, H.L. (19%) Zero VOC and high solids waterborne polyurethane dispersions. Coatings World, 10(1), 18-22. 

BajdiydroL [Miles] Polyurethane dispersion adhesion promoters in metal/plas-tic composites, textile and leather coatings, primers for rigid surface caodngs. 

An important class of waterborne coatings is the family of polyurethane dispersions (PUDs). lonizable groups (usually carboxyl) incorporated to the PU backbone allow the polymer to be dispersed in water after neutralization with amines. The properties can be varied substantially depending on the structure of the polyol and diisocyanate used to prepare them. Aliphatic and cycloaliphatic isocyanates are preferred because of their low reactivity with water and... 

Hemmerich J, Fikkert J, Berg M. Porous structural forms resulting from aggregate modification in polyurethane dispersions by means of isothermic foam coagulation. J Coated Fabrics 1993 22(4) 268-78. 

J. Kozakiewicz, Aqueous Polyurethane Dispersions as Coating Binders, presented at Ekolak Symposium, Ustron, Poland, 1993. 

A discussion is presented of the use of UV curable polyurethane dispersions for the manufacture of caul paper. Caul paper includes several types of embossing papers and casting foils, either plastic or paper, which are used to transfer a functional surface texture or grain onto a coating. Advantages offered by the use of UV curable PU dispersions in this particular application are discussed. 3 refs. 

An overview is presented on the merits of polyurethane dispersions in waterborne paint formulations. In addition to the characteristics listed which they impart to coatings, such binders can offer an even wider range of properties by means of blending or copolymerisation, producing binders which are tailor made for specific applications, it is stated. 

Polyesterpolyols based on dimer acids or dimer diol have been largely used in sol-vent-borne and water-based coating applications including alkyd resins and aqueous polyurethane dispersions. ... 

Solutions (5-25% solids) of fully reacted polyurethanes based on MDI or IPDI are also used in coating applications. These coatings are used mostly as finish coats on fiexible substrates. Because of concern over airborne solvents aqueous polyurethane dispersions are used today. These polymers are prepared by incorporating ionic groups into their backbone, and both cationic and anionic groups are utilized in the preparation of the ionomers. The solvent and water resistance of films formed from aqueous dispersions can be improved by cross-linking. Ionomers are also used in the formulation of speciality adhesives. 

The hydroxy-functional polyurethane dispersions can be cross-linked with MF resins or blocked isocyanates. Blocked isocyanates can also be used with water-reducible anionic acrylic or polyester resins instead of an MF resin oxime blocked isocyanates are commonly used, owing to their high reactivity. Oxime blocked aliphatic isocyanates are more stable to hydrolysis than oxime blocked aromatic isocyanates (32). As mentioned earlier alcohol blocked isocyanates are used in cationic electrodeposition coatings. 

Coatings (qv) present a unique stabilization challenge because of their high surface-to-volume ratio. Coatings, like polymers, are classified as either thermoplastic or thermoset. Thermoplastic coatings are those that are composed mainly of individual polymer chains, sometimes partially branched. Ebcamples of this type are acrylic latex paints, polyurethane dispersions, and nitrocellulose lacquers. 

Lu Y, Larock RC. Soybean oil-based, aqueous cationic polyurethane dispersions synthesis and properties. Prog Org Coat 2010 69(l) 31-7. 

Silicone polyethers of the A[BA] type (A = polyether, B = siloxane Fig. 6f) even allow the formulation of antifoams that are completely free of hydrophobic particles [72]. Compatibility of these antifoams is excellent, allowing their use in such sensitive applications as polyurethane dispersions, which are used as binders for floor coatings or automative coatings where even a very small number of craters on a large coated area enforces costly rework. The specific structure of the A[BA] copolymers lets them enter and weaken the surfactant layer of foam lamellae very efficiently. 

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