Gloss Reducers

Products prepared of thermoplastic molding compositions are often times glossy, yet for some applications this is not a desirable 

Elimination of gloss by surface embossing has been practiced but requires a separate step and adds cost. Moreover, subsequent abrasion may remove the embossed surface and cause the gloss to reappear (31). 

Addition of a finely divided filler, such as silica, silicate or alu-minate has been demonstrated to reduce the gloss of thermoplastic molding compositions yet this is often accompanied by an undesirable reduction in the level of at least some physical and/or mechanical properties of the molded article. 

Another straightforward method to reduce the gloss consists in admixing a dull graft copolymer as dulling agent (33). Such copolymers may be prepared from n-butyl acrylate, allyl methacrylate, and hydroxypropyl methacrylate. Likewise, hydroxypropyl methacrylate may be substituted by maleic anhydride. The polymerization is started by 2,2 -azobi sisobu ty roni trile and peroxides. 

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There are at least five types of synthetic silicas that can be considered for use in polymers. These are generally known as fumed, arc, fused, gel and precipitated. A detailed review of their production and uses has been given by Watson [96]. The types most often encountered in thermoplastics are the gel and precipitated silicas which are frequently used as antiblocking agents in polymer films and as gloss reducing agents in polymer sheets. 

Paraloid . [Rohm Haas Rohm Haas Europe] Acrylic-based polymm inqirot modifier, toughener, blending ad dve, gloss reducer, processing aid. 

Features Improves gloss, reduces flooring problems higher color strength... 

Acid mixtures are used to oxidize and remove the dark materials. Proper control gives a series of bleached waxes. A white wax requires double refining and reduces the yield to about 30% of the cmde wax input. A series of synthetic waxes is prepared by separating the acids and alcohols produced during saponification of the wax and reesterifying them with acids or alcohols selected to give desired properties of hardness, solubiHty, emulsification, and gloss. 

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