Water-saving process for preparing dinitrodiazophenol without powder dust

Water-saving process for preparing dinitrodiazophenol without powder dust

CN
  • CN 1,294,108 A
  • Filed: 01/20/2000
  • Published: 05/09/2001
  • Est. Priority Date: 10/29/1999
  • Status: Abandoned Application
First Claim
Patent Images

1. , water-saving process for preparing dinitrodiazophenol without powder dust is characterized in that:

  • 1) neutralization, reduction reaction operationA;

    raw material;

    Water12.5% Na 2S solution Crystal picric acid;

    B;

    feed ratio (weight ratio);

    Water;

    Na 2S;

    picric acid=(2-8);

    (3-5);

    1 C;

    technological process;

    In water temperature is 50 ±

    5 ℃

    water, add Na 2S solution makes solution PH between 8-10, and then, equivalent adds Na simultaneously 2S solution, picric acid crystal are finished neutralization reaction, subsequently, and with remaining Na 2S solution all adds, and the reduction reaction terminal point whether occurs detecting with " alkali skin ", finishes reduction reaction, generates picramic acid sodium, and behind the suction filtration, product is standby.2) doazo reaction operation;

    A;

    the single reinforced method of hydrochloric acid;

    a;

    raw material;

    Picramic acid sodium, water, 8% hydrochloric acid soln, 10% sodium nitrite solution, pyrogallol crystal, 20%NaOH solutionB;

    feed ratio;

    (weight ratio)Picramic acid sodium;

    water;

    NaNO 2;

    hydrochloric acid;

    pyrogallol;

    NaOH=1;

    2~

    15;

    4~

    7;

    3~

    7;

    0.001~

    0.003;

    0.02~

    0.04c;

    technological process;

    In 30 ±

    3 ℃

    water, add picramic acid sodium, Sodium Nitrite, pyrogallol, NaOH, stir simultaneously, then in 5~

    20 minutes, add 45~

    95% of hydrochloric acid total amount continuously with fast speeds, subsequently, in 5~

    50 minutes, add the residual salts acid solution continuously with slower speed, obtain end product DDNP.B;

    interior extrapolation diazonium operation;

    a;

    raw material;

    Picramic acid sodium, water, 6-8% hydrochloric acid, 6-8% Sodium Nitrite b;

    feed ratio;

    (weight ratio)Picramic acid sodium;

    water;

    hydrochloric acid;

    Sodium Nitrite=1;

    5~

    15;

    3~

    7;

    3~

    7c;

    technological process;

    In 30 ±

    3 ℃

    water, add picramic acid sodium, stir, simultaneously, in 5~

    20 minutes, add hydrochloric acid continuously, 45~

    95% of sodium nitrite solution total amount, subsequently, keep hydrochloric acid adding speed constant, and be controlled in 5~

    50 minutes, add remaining sodium nitrite solution, get final product DDNP.3) flushing, drying process;

    The doazo reaction product separated obtaining crystallization DDNP with the upper strata reaction mother liquor, drying is sieved, and the dress box is standby.

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