71.
    发明专利
    未知

    公开(公告)号:DE3927812A1

    公开(公告)日:1991-02-28

    申请号:DE3927812

    申请日:1989-08-23

    Applicant: BASF AG

    Abstract: Cationic urea formaldehyde resins are obtained by condensation of urea and formaldehyde in a molar ratio of 1:1.5 to 3 in the presence of at least 1 mol% of polymerizates, obtained by polymerization of vinyl amine units, with Fikentscher K values of 5 to 300 in a quantity of 5 to 100 g/mol of urea in the end-product. The mixture is first a) precondensed at a pH of 8 to 14, then acidified and b) condensed at a pH of 1 to 5 until the onset of gel formation, c) 0.3 to 1.5 mol of formaldehyde per mol of urea used is added, d) subsequent condensation is carried out and e) the resin solution is then neutralized. The resins so obtained are used as additives in paper manufacture to increase the dry and wet strength of paper and reduce the loss of opacity of the whiteness of the paper.

    72.
    发明专利
    未知

    公开(公告)号:DE3675593D1

    公开(公告)日:1990-12-20

    申请号:DE3675593

    申请日:1986-06-14

    Applicant: BASF AG

    Abstract: A novel fixed-bed catalyst structure obtained using honeycomb elements, for highly exothermic and endothermic chemical reactions, wherein the required heat exchange, both in the liquid phase and in the gas phase, is forcibly effected in the fixed catalyst bed by means of static mixing elements made of inert ceramic and/or metallic material or completely of catalyst material, between the individual honeycomb elements.

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