1.
    发明专利
    未知

    公开(公告)号:DE59003682D1

    公开(公告)日:1994-01-13

    申请号:DE59003682

    申请日:1990-09-12

    Applicant: BASF AG

    Abstract: Preparation of copolymers which are clear in water from A) 45 to 90% by weight of N-vinylpyrrolidone, B) 10 to 55% by weight of a vinyl ester and C) 0 to 10% by weight of further copolymerisable monomers by free radical polymerisation in an organic solvent in the presence of a free radical initiator and separation of the organic solvent and other volatile components by distillation, by carrying out the polymerisation until the N-vinylpyrrolidone content of the reaction mixture corresponds to 5 to 1% by weight of the amount of N-vinylpyrrolidone used, substantially separating off the organic solvent and other volatile components by distillation, adding water to the mixture, leaving the aqueous solution for 1 to 10 hours at 50 to 100 DEG C with further addition of free radical initiators and then virtually completely removing volatile organic components by steam distillation.

    4.
    发明专利
    未知

    公开(公告)号:DE3785017D1

    公开(公告)日:1993-04-29

    申请号:DE3785017

    申请日:1987-12-05

    Applicant: BASF AG

    Abstract: Hydrazine-free N-vinyl-2-pyrrolidone polymers (PVP), which form clear solns. in water and organic solvents and contain min. 50 (wt.)% polymerised N-vinyl-2-pyrrolidone (VP) are prepd. by treating the aq. monomer soln. with 0.1-3 wt.% (w.r.t. the monomer) of di-tert.-butyl peroxide (DTBP), opt. diluted up to 100 fold in soln. or emulsion; stirring the mixt. for 1-15 h at 100-160 deg.C; and adjusting the mol.wt. to a Fikentscher K value of 10-100 as required by adding 0-100% regulator w.r.t. the monomer. Pref., the mol.wt. regulator is i-PrOH.

    6.
    发明专利
    未知

    公开(公告)号:DE3931681A1

    公开(公告)日:1991-04-04

    申请号:DE3931681

    申请日:1989-09-22

    Applicant: BASF AG

    Abstract: Preparation of copolymers which are clear in water from A) 45 to 90% by weight of N-vinylpyrrolidone, B) 10 to 55% by weight of a vinyl ester and C) 0 to 10% by weight of further copolymerisable monomers by free radical polymerisation in an organic solvent in the presence of a free radical initiator and separation of the organic solvent and other volatile components by distillation, by carrying out the polymerisation until the N-vinylpyrrolidone content of the reaction mixture corresponds to 5 to 1% by weight of the amount of N-vinylpyrrolidone used, substantially separating off the organic solvent and other volatile components by distillation, adding water to the mixture, leaving the aqueous solution for 1 to 10 hours at 50 to 100 DEG C with further addition of free radical initiators and then virtually completely removing volatile organic components by steam distillation.

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