Antiblocking additives clarity/slip antiblocks

Synthetic silica is another high-clarity antiblock, but as with DE, it has the highest hardness of these additives and thus can easily damage metal tool surfaces. It also tends to absorb slip agents and can be hard to disperse, and, like DE, it absorbs moisture and is expensive [7-20]. 

Woods and Pocius [42] prepared commercial polyolefin plastomer films, containing slip and antiblock, were blown with and without the addition of commercial polymer processing additives, at levels of 600,1,200, or 2,000 ppm. Possible detrimental affects on the films were evaluated by determination of surface tension, gloss, haze, clarity, transmittance, hot tack, heat seal, coefficient of friction and block, and the surface... 

Masterbatches for PE have been described that contain a clarifying agent, a high clarity antiblock and an amide slip additive (6). These masterbatches can be used for the production of articles from both low density poly(ethylene) and linear low density poly(ethylene) by either a cast, blown or molding process. The articles show an increased gloss, a reduced haze, a reduced coefficient of friction, as well a reduced blocking force. The slip agent is erucamide. 

Fatty acid amides are well known as an important class of polymer additives used as a slip agent or lubricant to prevent unwanted adhesion. Unfortunately the addition of such amides for the purpose of antiblock additives for polymer sheets, in glass laminates (reduction of imwanted adhesion between surfaces of the polymer sheet itself) adversely affects the optical characteristics of the polymer sheet, such as haze, transparency, and film clarity, as well as adhesion of the polymer sheet to glass. Consequently, the inclusion of fatty acid amides polymer sheet interlayers in glass laminates is necessary. 

Two major directions of research are important for improvement of performance of inorganic antiblocking additives better optical clarity and elimination of influence on slip additives. Antiblocking inorganic additives increase haze and reduce gloss. Some improvements in optical qualities of talcs were reported. ... 

In summary, most optical properties are only slightly affected by addition of antiblocking, release, and slip additives. Film clarity is the only parameter affected by antiblocking additives. This deficiency seems to be the subject of ongoing research. 

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