Korea Research Institute of Chemical Technology

Cqv Co., Ltd.

Kwang Su Lim

Jung Min Lee

Jeong Kwon Suh

Byung Ki Park

Sung Yun Jo

Kwang Choong Kang

Gil Wan Chang

Dong Uk Choe

Kil Wan Chang

The present invention relates to a pearlescent pigment with large aspect ratio and a method of their preparation, and particularly to pearlescent pigments prepared by coating a metal or metal precursor on the flaky alpha-alumina crystals obtained by using an aluminum precursor aqueous solution and a zinc precursor aqueous solution as main ingredients. The crystals herein has an average particle thickness of 0.5 &#x3bc;m or less, an average particle diameter of 15 &#x3bc;m or higher and a large aspect ratio of 50 or higher, thereby being superior in gloss. The crystals show metal colors and interference colors of silver, gold, red, purple, blue and green.

Pearlescent pigments with large aspect ratio and a method of their preparation

The present invention relates to flaky alpha-alumina crystals with large aspect ratio and its preparation method, and particularly to flaky alpha-alumina crystals comprising aluminum oxide, zinc oxide and tin oxide, which are prepared by obtaining a mixed gel which are prepared by obtaining a mixed gel by means of hydrolysis of an aqueous aluminum precursor solution comprising aqueous flux, aqueous zinc precursor solution and tin precursor aqueous solution, followed by aging, drying and crystallization processes. The crystals herein have an average particle thickness of 0.5 &#x3bc;m or less, an average particle diameter of 30 &#x3bc;m or higher and an aspect ratio of 100 or higher, thus being useful as a substrate of high quality pearlescent pigments, an abrasive, ceramic material and a filling material.

Flaky alpha-alumina crystals with large aspect ratio and a preparation method of the same

The present invention relates to a flaky &#x3b1;-alumina crystal and a preparation method thereof. More particularly, the present invention relates to a flaky &#x3b1;-alumina crystal comprising aluminum oxide and zinc oxide, which is prepared by hydrolyzing an aluminum precursor solution containing a water-soluble flux and a zinc precursor solution to obtain a gel mixture and aging, drying, calcining and crystallizing it under a specific reaction condition, and a preparation method thereof. Since the flaky &#x3b1;-alumina crystal of the present invention has a thickness of less than 0.5 &#x3bc;m, an average particle diameter of at least 15 &#x3bc;m and an aspect ratio of at least 50, it is useful as high-quality pearlescent pigment material and filler for ceramic materials.

Flaky alpha-alumina crystal and a method of its preparation

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Cheongju-si, South Korea

Kwang Su Lim