Plastic substrates, abrasion-resistant coatings

Polysiloxane-Silica Hybrid Resins as Abrasion-Resistant Coatings for Plastic Substrates... 

H. Morgner, F. Haendel, C. Metzner, Transparent, abrasion resistant coatings on plastic and metal substrates, in Proceedings of the 50th Annual Technical Conference, Society of Vacuum Coaters, 2007, p. 252. 

Many of the attributes of solvent-borne epoxy coatings could be carried over to the waterborne epoxy coatings. These same attributes are useful in the application of waterborne epoxies as adhesive systems. They include good adhesion to a variety of substrates such as metals, wood, concrete, glass, ceramics, and many plastics chemical resistance low shrinkage toughness and flexibility and abrasion resistance. 

It is necessary to thermally cure the coated plastic in order to achieve full crosslinking of the air dried film. The degree of crosslinking affects not only the abrasion resistance of coating, but also the adhesion and the long term performance under environmental conditions. The temperature and time of cure is also dictated by the thermal stability and properties of the plastic substrate. The following table lists recommended cures for various plastics. 

Uses Abrasion resist, aid, toughener, flexibilizer, hardener, gloss aid in water-based coatings (automotive OEM, refinish, primers, basecoats, topcoats), adhesives for wood/plastic/metal substrates, inks binder in waterborne inks, bonding and laminating applies. 

Uses Abrasion resist, aid, toughener, flexibilizer, hardener, gloss aid in water-based coatings (automotive OEM, refinish, primers, basecoats, topcoats), adhesives for wood/plastic/metal substrates, inks Features Low vise. exc. adhesion to substrates crosslinkable thru carboxyl groups provides improved soK/ychem. resist, when crosslinked Properties Vise. 50-100 cps pH 9.5 VOC 0.3 Ib/gal film props, after 30 min 120 C hardness ( ard) 55 tens. str. 5500 psi elong. 260% 100% mod. 3400 psi 35 A solids... 

Chem. Desaip. Amine-modified bisphenol A epoxy diacrylate oligomer Uses Epoxy-acrylic for clear coatings for paper and plastics, topcoats for wood, screen and lithographic ink vehicles Features Improves prod, performance (cure response, chem. resist., flexibility, abrasion resist., gloss, adhesion to plastic substrates)... 

Chem. Deserp. Aromatic urethane acrylate oligomer Uses Film-former for U V/EB coatings and inks, clear overprint varnishes and pigmented systems on wood, metal and rigid plastic substrates Features Fast cure pourable exc. scratch and abrasion resist, chars. ... 

Protective optical coatings Abrasion resistance silica gel ccating cn plastic substrates... 

Proposed applications include films for food packaging, making use of the reduced permeability feature of exfoliated montmorillonites. In the packaging industry, for instance, certain foods, (e.g. tomato products and beer) are sensitive to oxygen owing to the permeability of the plastic. The fire retardant property of these composites is also frequently mentioned (93). Other proposed applications include thin-walled medical tubing, abrasion-resistant and chemical-resistant coating, especially for transparent substrates. 

Recently there has been increased use of surface coating materials, i.e. printing inks, metallization, or painting, to enhance the appearance and surface-related properties of plastics (e.g. barrier properties to gases or UV radiation, or increased abrasion resistance). Usually such treatment is accompanied by pretreatment to modify the surface of the polymer and to ensure adhesion of the surface coating to the substrate. 

The mechanical properties of coated plastic parts are largely determined through a combination of the paint formulation and the plastic substrate. When we refer to mechanical properties, we arc referring to properties such as hardness, flexibility, impact, solvent and abrasion resistance, and even adhesion. Schoff (29)... 

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