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    1.
    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

    Inventor： FLORY KLAUS DR ,  STANGE ANDREAS DR ,  KROENER MICHAEL DR ,  SENDHOFF NORBERT DR

    IPC: C08G12/12 ,  C08G12/46 ,  D21H17/49 ,  D21H17/50

    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.

    5.
    发明专利
    未知

    公开(公告)号：DE3909007A1

    公开(公告)日：1990-09-27

    申请号：DE3909007

    申请日：1989-03-18

    Applicant: BASF AG

    Inventor： FLORY KLAUS DR ,  EISELE WOLFGANG DR ,  STANGE ANDREAS DR

    IPC: C08G12/04 ,  C08G12/12 ,  C08G12/14 ,  C08G12/38 ,  D21H17/49 ,  D21H17/51 ,  D21H19/24

    Abstract: Cationic urea-formaldehyde condensates, which may be obtained by (a) the conversion of urea with alkanol amines in the mol ratio 1 to 6:1 at temperatures of 130 to 180 DEG C with separation of ammonia; (b) the methylolisation of the conversion products obtained in step (a) in an aqueous medium in the basic pH range with formaldehyde; (c) the condensation of the methylolisation products in an aqueous medium at a pH of 0 to 6, the condensation reaction being stopped by setting the pH to between 6.2 and 8 and, where necessary, diluting the reaction mixture with water; a process for manufacturing the condensates, and their use as stiffening agents in papermaking.

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