Patents with Abstracts (1)
3. “In order to improve the crystallizability of a polyolefin-based resin to better the resin transparency and also to provide heat-resistance and mechanical strength, a variety of crystal nucleating agents are widely used. In addition, it is known that the crystallization of a polyolefin-based resin during molding is made controllable by adding a certain compound or composition to the polyolefin-based resin. In general, a polyolefin-based resin whose crystallizing action is facilitated may attain advantages in, for example, that the molding cycle time is shortened, that the transparency of the molded articles of the polyolefin-based resin is improved, and that the heat-resistance and physical characteristics are improved. Examples of such crystal nucleating agent include metal carboxylates such as sodium benzoate, aluminum 4-tert-butyl benzoate, sodium adipate, disodium-bicyclo[2.2.1]heptane-2,3-dicarboxylate; phosphoric ester metal salts such as sodium-bis(4-tert-butylphenyl)phosphate, sodium-2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate and lithium-2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate; and polyalcohol derivatives such as dibenzylidene sorbitol, bis(methylbenzylidene)sorbitol and bis(dimethylbenzylidene)sorbitol.” [Urushihara et al, US Patent 8,288,462 (10/16/2012)]
2. Nucleating and clarifying agents are chemical compositions that may be added to thermoplastic polymers to facilitate polymer crystallization as it changes from molten to solid form in the process of crystallization. Such additives may assist in reducing haze of polymeric structures. Many different chemical compositions are known for this purpose. One major issue in the use of such agents is the amount or degree of clarity that the agent or additive imparts to a finished polymeric article. Reducing haze and thereby increasing clarity of such articles is a constant endeavor in the plastics industry.
“In general, the use of nucleating agents is a highly unpredictable technology area. Small or slight changes in a molecular structure can drastically change the ability of a given nucleating composition to nucleate or clarify effectively a polymer composition. There is a large amount of unpredictability in the art of nucleating agents. There are many unknowns regarding the effect of a given substance on polymer morphology during recrystallization of thermoplastics.”
[Hanseen, US Patent 7,879,933 (2/1/2011)]
1. “Typical nucleating agents known in the art include minerals, such as chalk, clay, kaolin, talc, silicates, and the like. Organic nucleating agents, such as salts of aliphatic or aromatic carboxylic acids, aromatic salts, metallic salts of aromatic phosphorus compounds, quinaridones, aromatic amides, and polymers having melting points are more efficient.” (Ma et al, Chemtura Corporation, US Patent 7,569.630, 8/4/2009)
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Roger D. Corneliussen
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Copyright 2012 by Roger D. Corneliussen.
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* Date of latest addition; date of first entry is 8/4/2009.