Page 67 - Handbook of Surface Improvement and Modification

62 Surface Matting (Flattening)

crosslinking of the uretdione isocyanate groups and the resin component during curing
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yields a film with a low level of gloss (3 or less) and sheen (8 or less).
A matte coating composition for automotive interior contains a binder resin, a wax-
based dulling agent (polyethylene, polypropylene, polytetrafluoroethylene, or their combi-
nations), and a silica-based dulling agent (silica-rubber powder, silicone resin powder, or
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silicone powder having particle size of 0.2-30 μm).
An anti-glare, texture coating for packaging comprises a water emulsion of acrylic
beads having an average particle size smaller than 10 microns, an acrylic-based carrier,
and particles having an average particle size of from about 10 to 125 microns of either
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polyamide, polyethylene, polypropylene, polytetrafluoroethylene or their combinations.
The low-gloss soft-feel layer is a part of low-gloss soft-touch thermoformable paint
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film laminate. The low-gloss, soft-touch coating is frequently formed by the surface
micro-roughness transfer from a matte release liner. In the invention, the low-gloss soft-
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feel layer is a clearcoat layer. The liquid coating composition comprises a polycarbonate
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diol and a hydroxyl-reactive crosslinker.
The coating has resistance to burnishing even at extremely low gloss, coupled with
great scratch resistance, without compromising either the visual or tactile qualities of the
finish or those characteristics that make the coating formulation suitable for industrial
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application. The coating contains a linear binder bearing a small proportion of reactive
groups for crosslinking (linear polyester polyol binder with OH% of 0.5 to 3), crosslinking
agents of different reactivity (e.g. TDI-HDI 3:2 polyisocyanate and HDI isocyanurate),
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and a silica matting agent (e.g., pyrogenic silica).
A thermoplastic elastomer compound is a blend of styrenic block copolymer, ther-
moplastic vulcanizate, thermoplastic polyurethane, a compatibilizer, and a masterbatch
containing silicone, which is added to provide a qualitative silky feel on surfaces of plastic
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articles made from the compound. The resultant products have a combination of a silky
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feel and a matte finish.
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A method of forming an anti-glare coating on a substrate comprises:
(a) heating the substrate to a temperature of 37.8°C to form a hot substrate;
(b) applying a curable film-forming sol-gel composition having a surface roughness
(c) subjecting the coated substrate to conditions to effect cure.
The sol-gel network layer is composed of a tetraalkoxysilane; an epoxy functional tri-
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alkoxysilane; a metal-containing catalyst; and a solvent. Coated articles have anti-glare
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properties.
The coating can be prepared with lower sheen and matte finishes that are ordinarily
not available for high moisture areas, such as baths and spas, but are desirable and often
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preferred due to their rich appearance and depth of color. The coating composition con-
tains a vinyl acrylic copolymer latex which exhibits a hydrophobic surface, micronized
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amorphous silica, and a silicone additive.
REFERENCES
1 Sheikhattar, M; Attar, H; Sharafi, S; Carty, WM, Mater. Charact., 118, 570-4, 2016.
2 Valdesueiro, D; Hettinga, H; Drijfhout, JP; Lips, P; Meesters, GMH; Kreutzer, MT; van Ommen, JR,
Powder Technol., 318, 401-10, 2017.
3 New technology for dull and semi-matte powder coatings, Focus Powder Coat., 2010, 6, 2-3, 2010.
4 Salgado, VE; Cavalcante, LM; Silikas, N; Schneider, LFJ, J. Dentistry, 41S, e45-e53, 2013.
5 Rubinson, EH, WO2015167659, Avon Products, Inc., Nov. 5, 2015.