64.
    发明专利
    未知

    公开(公告)号:NO880856D0

    公开(公告)日:1988-02-26

    申请号:NO880856

    申请日:1988-02-26

    Applicant: BASF AG

    Abstract: Paper and paperboard of high dry strength are produced by adding a dry strength enhancer to the paper stock and dewatering the paper stock with sheet formation by using as the dry strength enhancer a mixture of a cationic polymer which contains as characteristic monomers copolymerized units of (a) diallyldimethylammonium chloride, (b) N-vinylamine or (c) a substituted or unsubstituted N-vinylimidazoline and has a K value of not less than 30, and natural potato starch which is converted into a water-soluble form by heating in an aqueous medium at above the gelatinization temperature of natural potato starch in the absence of any oxidizing agents or alkali.

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