Milliken & Company

Milliken Research Corporation

Michael J Mannion

Jeffrey R Jones

Nathan A Mehl

Jiang Li

Jiannong Xu

Diacetals of sorbitols and xylitols are employed in polyolefins as nucleating agents. Diacetals of sorbitols and xylitol nucleating agents may be provided in granular or powder form from hoppers or mixing equipment into polyolefins during the formation of polymeric compositions and polymeric articles. Flow of diacetals of sorbitols and xylitols is improved by the use of certain silicas, in certain defined weight percentages. Submicron size range silica compounds may provide excellent flow enhancement properties when blended and used with diacetals of sorbitols and xylitols powder compounds. A hydrophobic silica mixed with diacetals of sorbitols and xylitols compounds also may provide enhanced flow properties for such mixture, as compared to mixtures using hydrophilic silica. Loading ranges of silica may be important in improving the flow of diacetals of sorbitols and xylitols compounds.

Silica-containing nucleating agent compositions and methods for using such compositions in polyolefins

Milled, small particle size, solid bicyclo[2.2.1]heptane dicarboxylate salt-containing thermoplastic nucleating additive formulations further comprising at least one anticaking agent for improved haze reduction, improved nucleation performance, and prevention of potential cementation (via agglomeration) of the salt component present therein are provided. Such small particle size dicarboxylate salts provide desirable properties within thermoplastic articles, particularly as nucleating agents, but apparently suffer from certain clarity issues and agglomeration problems (due to the flat and thin plate structures of such compounds and the propensity they exhibit to cohere to each other during storage), making utilization thereof less desirable for certain applications. Thus, an improvement has been provided to permit full benefit of the excellent crystallization temperatures, stiffness, and calcium stearate compatibility such dicarboxylate salts accord within target low haze thermoplastics. Furthermore, unexpected improvements in dusting reduction have been found upon the utilization of such anticaking additives in combination with the aforementioned nucleating salts. Thermoplastic additive compositions and methods of producing thermoplastics with such nucleator/anticaking additive combinations are also contemplated within this invention.

Nucleating additive formulations of bicyclo[2.2.1]heptane dicarboxylate salts

A process for thermoforming a polyolefin resin sheet is provided having an aromatic aldehyde-polyhydric alcohol condensation product incorporated in the sheet to limit deformation of the sheet during the heating step.

Method of thermoforming polyolefin resin

A process for incorporating a clarifying agent into a semi-crystalline polyolefin resin is provided whereby a clarifying agent selected from compounds having the formula: ##STR1## wherein p is 0 or 1, m and n are independently 0-3, and R is, at each occurrence, independently selected from C.sub.1-8 alkyl, C.sub.1-4 alkoxy, hydroxy, halogen, C.sub.1-6 alkylthio, C.sub.1-6 alkylsulfoxy and a 4 or 5 membered alkyl group forming a carbocyclic ring with adjacent carbon atoms of the unsaturated parent ring, and wherein the clarifying agent is in the form of a powder characterized by a d.sub.97 of 30 microns or less, and a mean particle size of 15 microns or less, is blended with the polyolefin resin, at a temperature above 170.degree. C. until the clarifying agent is dissolved in the molten resin.

Polyolefin composition containing ultrafine sorbitol and xylitol acetals

A process for incorporating a clarifying agent into a semi-crystalline resin is provided whereby a clarifying agent selected from compounds having the formula: ##STR1## wherein p is 0 or 1, m and n are independently 0-3, and R is, at each occurrence, independently selected from C.sub.1-8 alkyl, C.sub.1-4 alkoxy, hydroxy, halogen, C.sub.1-6 alkylthio, C.sub.1-6 alkylsulfoxy and a 4 or 5 membered alkyl group forming a carbocyclic ring with adjacent carbon atoms of the unsaturated parent ring, and wherein the clarifying agent is in the form of a powder characterized by a d.sub.97 of 30 microns or less, and a mean particle size of 15 microns or less, is blended with the polyolefin resin, at a temperature above 170.degree. C. until the clarifying agent is dissolved in the molten resin.

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Spartanburg, SC, United States of America

Michael J Mannion