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Патент USA US2259563

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Patented Oct. 21, 1941
William H. Hill, Mount Lebanon, Pa., assignor to
American Cyanamid Company, New York, N. Y.,
a corporation of Maine
No Drawing. Application December 30, 1939,
Serial No. 311,939
4 Claims.
(Cl. 260—553)
The present invention relates to methods for ‘
producing guanyl urea sulphamate.
Example II
Molar proportions of dicyandiamid, sulphamic
The formation of this substance may be readily
acid and water were slowly heated together.
accomplished by hydrolyzing dicyandiamid with
Suddenly, at about 80 to 100° C., a violent re
sulphamic acid in the presence of water. As a 5 action took place, the contents of the beaker ris
result of this reaction, a melt is formed con
ing to the rim, then subsiding. The resultant
taining guanyl urea sulphamate from which this
product was a thick, glassy material, perfectly
substance may be readily obtained in a purer
clear, which gave with copper sulphate and so
state by recrystallization from water.
dium hydroxide a test indicating a mixture of
Guanyl urea sulphonic acid may be obtained
sulphonate and sulphamate since the solution
from guanyl urea sulphamate by heating the
was colored pink and contained a small amount
latter to from 140 to 180° C. As a result of this
of a pink precipitate. Continued heating in the
reaction, there is evidence that some ammonium
neighborhood of 160° C. and until no more am
guanyl urea sulphonate is formed. The yields
monia was evolved, resulted in a clear yellow
of the free acid may, therefore, be increased by 15 melt which, when the same was leached with
digesting the crude melt with water and a min
water, was found to be substantially pure guanyl
eral acid, such as sulphuric acid, or by protracted
urea sulphonic acid contaminated with a mini
heating of the melt until no more ammonia is
mum amount of the ammonium-salt.
This application is a continuation in part of
20 applicant's co-pending application Serial No.
Example I
305,176, ?led November 18, 1939.
490 grams of sulphamic acid were mixed with
While the invention has been described with
420 grams of dicyandiamid and 360 cc. of water
particular reference to speci?c embodiments, it
to form a thin paste. The mix was then heated,
is to be understood that it is not to be limited
during which time it assumed a yellow color and 25 thereto but is to be construed broadly and re
became more ?uid. When the temperature
stricted solely by the scope of the appended
reached 75° C., it was evident that a reaction
was rapidly progressing and became violent at
I claim:
95° C. At this point, the source of heat was re
1. A method of making guanyl urea sulpham
moved, although the temperature continued to
ate which comprises hydrolyzing dicyandiamid in
rise to approximately 115° C. The reaction con
the presence of sulphamic acid and water and
tinued at this temperature for some time during
recovering guanyl urea sulphamate therefrom.
which period steam escaped and a clear yellow
2. The method of claim 1 in which molar pro
melt resulted. After cooling, the solid product
portions of sulphamic acid, dicyandiamid and
was dissolved in water and a white crystalline 35 water are used.
solid, identi?ed as guanyl urea sulphamate, re
3. The method of claim 1 in which sulphamic
covered therefrom.
acid, dicyandiamid and water are heated to sub
Upon heating either the crude melt contain
stantially 75° C.
ing guanyl urea sulphamate or the recrystallized
4. The method of claim 1 in which the initial
product to 160° C., the melt becomes foamy and 40 reaction mixture comprises essentially sulphamic
ammonia escapes. After the reaction had sub
acid, dicyandiamid and water in substantially
sided, the product was found to contain substan
the proportions of 4590;420:360, respectively, the
tial quantities of guanyl urea sulphonic acid con
mixture being heated to substantially 75° C.
taining some of the ammonia salt thereof. A
whereby a clear yellow melt results, treating the
purer acid was obtained by digesting the crude
melt with water and recrystallizing guanyl urea
melt with water and a mineral acid such as sul
phuric acid to liberate additional quantities of
guanyl urea sulphonic acid. The latter was re
covered in puri?ed form by recrystallization from
sulphamate therefrom.
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