Preparation of gypsum compositions
    1.
    发明授权
    Preparation of gypsum compositions 有权
    石膏组合物的制备

    公开(公告)号:US07070648B1

    公开(公告)日:2006-07-04

    申请号:US11153966

    申请日:2005-06-16

    IPC分类号: C04B24/24

    摘要: A gypsum composition containing a sulfonate-containing comb-branched copolymer is disclosed. The sulfonate-containing comb-branched copolymer comprises recurring units of a polyether macromonomer, an acrylic monomer, and a sulfonate monomer. The sulfonate-containing comb-branched copolymer not only increases the fluidity of gypsum slurry but also has reduced retardation on the gypsum setting.

    摘要翻译: 公开了含有含磺酸酯的梳状支化共聚物的石膏组合物。 含磺酸酯的梳型支化共聚物包括聚醚大分子单体,丙烯酸单体和磺酸酯单体的重复单元。 含磺酸酯的梳状支化共聚物不仅增加了石膏浆料的流动性,而且降低了石膏的延迟。

    Process for the preparation of unsymmetric dialkyl carbonates
    10.
    发明授权
    Process for the preparation of unsymmetric dialkyl carbonates 失效
    制备不对称二烷基碳酸酯的方法

    公开(公告)号:US5206408A

    公开(公告)日:1993-04-27

    申请号:US886719

    申请日:1992-05-21

    IPC分类号: C07C68/06

    CPC分类号: C07C68/06

    摘要: Basic cesium compounds are effective transesterification catalysts for the conversion of symmetric dialkyl carbonates to unsymmetric dialkyl carbonates. Crown ethers, polyalkylene glycols, and polyalkylene glycol ethers are useful cocatalysts for the process. Methyl tert-butyl carbonate and methyl tertamyl carbonate, useful octane enhancers for gasoline, can be prepared using the process.

    摘要翻译: 碱性铯化合物是将对称二烷基碳酸酯转化为不对称二烷基碳酸酯的有效酯交换催化剂。 冠醚,聚亚烷基二醇和聚亚烷基二醇醚是该方法的有用助催化剂。 碳酸甲基叔丁酯和碳酸甲基叔戊酯,可用于汽油的有用的辛烷值增强剂。