66.
    发明专利
    未知

    公开(公告)号:NO144208B

    公开(公告)日:1981-04-06

    申请号:NO744213

    申请日:1974-11-22

    Applicant: BASF AG

    Abstract: 1480921 Stabilizing aqueous formaldehyde BASF AG 25 Nov 1974 [26 Nov 1973] 50896/74 Heading C2C Aqueous formaldehyde solutions are stabilized by means of a bis-guanamine of formula wherein the two substituent on the phenylene ring are in m or p-position to each other. 0À001 to 0À5% by weight of stabilizer may be used and the formaldehyde solution may contain 28-65% by weight of formaldehyde. The stabilizer may be added as a stock solution in a formaldehyde solution of higher strength than that to be stabilized and having a pH of 2À5 to 5À8 and the latter is preferably kept at 40-80‹ C. for 10-30 hours before adding the stock solution.

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