U.S. patent application number 09/839199 was filed with the patent office on 2002-03-07 for process for the preparation of pure melamine.
Invention is credited to Canzi, Lorenzo, Coufal, Gerhard, Mullner, Martin.
Application Number | 20020028935 09/839199 |
Document ID | / |
Family ID | 27421668 |
Filed Date | 2002-03-07 |
United States Patent
Application |
20020028935 |
Kind Code |
A1 |
Canzi, Lorenzo ; et
al. |
March 7, 2002 |
Process for the preparation of pure melamine
Abstract
A process for the preparation of pure melamine, in which liquid,
ammonia-containing melamine is rapidly depressurized from an
ammonia partial pressure p.sub.1 between 400 and 50 bar to an
ammonia partial pressure p.sub.2 between 200 bar and atmospheric
pressure, where p.sub.1 is always greater than p.sub.2, at a
temperature which is 0 to 60.degree. C. higher than the melamine
solidification point dependent on the particular prevailing ammonia
partial pressure, higher pressures permitting a greater temperature
interval from the melamine solidification point than lower
pressures, by which means pure melamine separates out in solid
form, whereupon, in any sequence, the product is further
depressurized if appropriate to atmospheric pressure, cooled to
room temperature and the pure melamine is isolated.
Inventors: |
Canzi, Lorenzo; (Milan,
IT) ; Coufal, Gerhard; (Leonding, AT) ;
Mullner, Martin; (Linz, AT) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
27421668 |
Appl. No.: |
09/839199 |
Filed: |
August 13, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09839199 |
Aug 13, 2001 |
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09612941 |
Jul 10, 2000 |
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09612941 |
Jul 10, 2000 |
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09414633 |
Oct 8, 1999 |
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09414633 |
Oct 8, 1999 |
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09011183 |
Sep 23, 1998 |
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09011183 |
Sep 23, 1998 |
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PCT/EP96/05389 |
Dec 4, 1996 |
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Current U.S.
Class: |
544/203 |
Current CPC
Class: |
C07D 251/60 20130101;
C07D 251/62 20130101 |
Class at
Publication: |
544/203 |
International
Class: |
C07D 251/56 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 7, 1995 |
AT |
A 1994/95 |
Claims
1. A process for the preparation of substantially pure melamine,
which comprises rapidly depressurizing liquid, ammonia-containing
melamine frm an ammonia partial pressure p.sub.1 between 400 and 50
bar to an ammonia partial pressure p.sub.2 between 200 bar and 20
bar pressure, where p.sub.1 is always greater than p.sub.2, at a
temperature which is 0 to 60.degree. C. higher than the melamine
solidification point which is dependent on the particular
prevailing ammonia partial pressure, but is below 350.degree. C.,
higher pressures permitting a greater temperature interval from the
melamine solidification point than lower pressures, whereby pure
melamine separates out in solid form, whereupon, in any sequence,
optionally further depressurizing the resultant product to
atmospheric pressure, cooling to room temperature and isolating the
substantially pure melamine.
2. The process as claimed in claim 1, wherein a melamine to be
purified which is already present as melt or as liquid phase is
brought to the ammonia partial pressure desired for the
depressurization between about 400 to 50 bar, and to a temperature
which is about 0 to 60.degree. C. above the melamine solidification
point dependent on the particular prevailing ammonia partial
pressure.
3. The process as claimed in claim 2, wherein, in the process, the
temperature is decreased.
4. The process as claimed in claim 2, wherein, in the process, the
temperature is decreased at a cooling rate of 0.8 to 10.degree.
C./min.
5. The process as claimed in claim 2, wherein, in the process,
ammonia is fed.
6. The process as claimed in claim 2, wherein the NH.sub.3/CO.sub.2
gas mixture forming in the urea conversion is separated off from
the liquid melamine and the CO.sub.2 dissolved in the liquid
melamine is reduced by introducing gaseous ammonia.
7. The process as claimed in claim 1, wherein, before the
depressurization, the liquid melamine is allowed to dwell for about
5 minutes to 20 hours.
8. The process as claimed in claim 1, wherein, before the
depressurization, the liquid melamine is saturated with
ammonia.
9. The process as claimed in claim 1, wherein the depressurization
of the liquid, ammonia-containing melamine is carried out as
closely as possible to or above the solidification point of the
melamine dependent on the particular ammonia partial pressure.
10. The process as claimed in claim 1, wherein the liquid,
ammonia-containing melamine is depressurized to a pressure between
20 bar and about 200 bar.
11. The process as claimed in claim 1, wherein the depressurization
is performed in the vessel into which the liquid melamine was
introduced.
12. The process as claimed in claim 1, wherein the depressurization
is carried out by transferring or spraying into one or more
vessels.
13. The process as claimed in claim 11, wherein an ammonia
atmosphere is present in the vessels.
14. The process as claimed in claim 12, wherein approximately the
same temperature prevails in the vessels as in the receptacle from
which depressurization is performed.
15. The process as claimed in claim 12, wherein, after the
depressurization, the then solid melamine is allowed to dwell at a
pressure between 200 bar and 20 bar for about 1 minute to 20
hours.
16. The process as claimed in claim 1, wherein, after the
depressurization, the then solid melamine is allowed to dwell at a
temperature below about 290 .degree. C.
17. The process as claimed in claim 1, wherein the then solid
melamine is allowed to dwell at a temperature between about 280 and
250.degree. C.
18. The process as claimed in claim 1, wherein the already solid
melamine is cooled to room temperature by quenching with a cold,
liquid medium.
19. The process as claimed in claim 1, wherein it is carried out
continuously.
20. The process as claimed in claim 1, wherein it is carried out
immediately downstream of a melamine high-pressure process.
21. The process as claimed in claim 1, wherein the melamine to be
purified which is initially present as solid is heated at an
ammonia partial pressure between about 400 and 50 bar, to a
temperature which is about 0 to 60.degree. C. above the melamine
solidification point dependent on the particular prevailing ammonia
partial pressure.
Description
[0001] This is a continuation of Ser. No. 09/612,941, filed Jul.
10, 2000, now abandoned, which is a continuation of Ser. No.
09/414,633, filed Oct. 8, 1999, now abandoned, which is a
continuation-in-part of Ser. No. 09/011,183, filed Sep. 23, 1998,
now abandoned, which is a 371 of PCT/EP96/05389, filed Dec. 4,
1996.
[0002] A multiplicity of processes for the preparation of melamine
are already published in the literature. A preferred starting
material in these is urea, which is reacted either at high pressure
and non-catalytically or at low pressure and using a catalyst to
form melamine, ammonia and CO.sub.2.
[0003] Although the known high-pressure processes, for instance
those of Melamine Chemicals, Montedison or Nissan, in which the
melamine is first formed as a liquid, have a lower energy
consumption in comparison to low-pressure processes, if no
purification stages are present, melamine contains impurities such
as melam, melem, ammeline, ammelide or ureidomelamine, which
interfere with some further melamine processing operations.
[0004] Melamine prepared by a high-pressure process is worked up,
for example, according to U.S. Pat. No. 4,565,867 (Melamine
Chemicals) by separating off the CO.sub.2 and NH.sub.3 waste gases
from the liquid melamine, the pressure and temperature preferably
being maintained at the same values as in the reactor. The liquid
melamine is then fed to a product cooling unit, in which it is
depressurized from 105-175 bar to about 14-42 bar and at the same
time rapidly cooled and Quenched with liquid ammonia from
350-430.degree. C. to 48-110.degree. C., by which means melamine
separates out as a solid product.
[0005] According to U.S. Pat. No. 3,116,294 (Montecatini), the
CO.sub.2 and NH.sub.3 waste gases are likewise separated off first,
the liquid melamine is treated in countercurrent with NH.sub.3 to
remove CO.sub.2 still dissolved, and the product is collected in a
further reactor and allowed to dwell therein for a defined time.
Finally, melamine is taken off from the second reactor and rapidly
cooled by quenching with water or by mixing with cold gases.
[0006] However, the purity of melamine which is produced by one of
these processes is insufficient for many applications, for instance
in the preparation of melamine-formaldehyde resins for surface
coatings, since, in particular, the melem content is too high.
[0007] According to U.S. Pat. No. 3,637,686 (Nissan), the crude
melamine melt obtained by thermal decomposition of urea is rapidly
cooled to 200-270.degree. C. with liquid NH.sub.3 or cold NH.sub.3
gas, and is further cooled in a second step to 100-200.degree. C.
with aqueous NH.sub.3 solution. The product must then be
recrystallized in order to achieve a satisfactory melamine
purity.
[0008] The object of the present invention was therefore to find a
process which enables the preparation of pure melamine having a
purity of up to greater than 99.8% and having a markedly reduced
content of impurities, particularly melem and melam.
[0009] Unexpectedly, this object was able to be achieved by a
process in which liquid, ammonia-containing melamine is rapidly
depressurized at a temperature at or just above the solidification
point of melamine dependent on the particular prevailing ammonia
partial pressure, the solidification point, depending on the
temperature at the beginning of depressurization and the desired
final pressure, increasing by about up to 60.degree. C., and solid
melamine separating out.
[0010] The present invention therefore relates to a process for the
preparation of pure melamine, which comprises liquid,
ammonia-containing melamine being rapidly depressurized from an
ammonia partial pressure p.sub.1 between 400 and 50 bar to an
ammonia partial pressure p.sub.2 between 200 bar and 20 bar, where
p.sub.1 is always greater than p.sub.2, at a temperature which is 0
to 60.degree. C. higher than the melamine solidification point
dependent on the particular prevailing ammonia partial pressure,
higher pressures permitting a greater temperature interval from the
melamine solidification point than lower pressures, by which means
pure melamine separates out in solid form, whereupon, in any
sequence, the product is further depressurized if appropriate to
atmospheric pressure, cooled to room temperature and the pure
melamine is isolated.
[0011] The process according to the invention is suitable for the
purification of melamine which is produced in any known process of
the prior art and, in particular, contains impurities such as melem
and melam, the melamine being able to be present either as melt or
in the liquid phase or in crystalline form.
[0012] If the melamine to be purified is already present as melt or
as liquid phase, such as downstream of a high-pressure reactor for
the synthesis of melamine by conversion of urea, the pressure and
the temperature of the melt or the liquid melamine are brought to
the initial ammonia partial pressure desired for the
depressurization between about 400 and 50 bar, preferably between
about 400 and 80 bar, particularly preferably between about 300 and
100 bar, and to the corresponding above-defined temperature, i.e.
to a temperature which is about 0 to 60.degree. C., preferably
about 0 to 40.degree. C., particularly preferably about 0 to
20.degree. C., above the melamine solidification point dependent on
the particular prevailing ammonia partial pressure. In this process
it must be noted that at higher pressures the temperature
difference between melamine solidification point and the
temperature to be set at the beginning of depressurization can be
greater than at lower pressures, since the solidification point of
the melt at higher pressures is at lower temperatures than at low
pressures. In order to achieve the temperature desired for the
depressurization, the temperature is decreased if necessary. The
temperature is particularly preferably below about 350.degree. C.
Cooling can be carried out either rapidly or slowly. Preferably, it
is performed slowly at a cooling rate of 0.8 to 10.degree. C./min.
Since the melamine melt can absorb more ammonia at a lower
temperature, ammonia is preferably fed during this operation. It is
particularly advantageous to depressurize the liquid
ammonia-containing melamine as far as possible close to or above
the melamine solidification point dependent on the particular
prevailing ammonia partial pressure.
[0013] It is further possible by means of the present invention to
purify solid, contaminated melamine. The melamine to be purified,
which is present in crystalline form or as powder, is first heated
at an ammonia partial pressure between about 400 and 50 bar,
preferably between about 400 and 80 bar, particularly preferably
between about 300 and 100 bar, to a temperature which is about 0 to
60.degree. C., preferably about 0 to 40.degree. C., particularly
preferably about 0 to 20.degree. C., above the melamine
solidification point dependent on the particular prevailing ammonia
partial pressure. To melt solid melamine reliably, it is expedient
firstly to heat it to about 370.degree. C. and then to cool it to
the desired depressurization temperature to ensure that the
melamine is completly molten. Preferably, the desired
depressurization temperature is below about 350.degree. C.
[0014] Again it must be noted that the temperature difference at
higher pressures can be greater than at lower pressures.
[0015] Preferably, the process of the invention is carried out
directly after a melamine high-pressure process. Examples of
high-pressure processes are, for instance, the Melamine Chemical,
Montedison or Nissan process, as described, for example, in
Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Vol.
A16, pp. 174-179. According to these processes, urea is usually
converted in a temperature range from about 370 to 430.degree. C.
and at a pressure of about 70 to 300 bar. The melamine formed in
these processes is finally obtained as a liquid phase.
[0016] According to the process of the invention, the initial
ammonia partial pressure desired for the rapid depressurization is,
if necessary, set between about 400 and 50 bar. In order to set the
corresponding initial temperature for the depressurization, the
liquid melamine obtained from the urea conversion process is cooled
from the temperature prevailing in the reactor by means of suitable
cooling apparatuses, for instance by means of heat exchangers, to
the appropriate value, i.e. to a temperature which is about 0 to
60.degree. C., preferably about 0 to 40.degree. C., particularly
preferably about 0 to 20.degree. C., above the melamine
solidification point dependent on the particular ammonia partial
pressure set. Cooling can be performed in this process in any
manner either rabidly or slowly. Preferably, the cooling is carried
out at a rate which is between about 0.8.degree. C./min and
10.degree. C./min, preferably with further ammonia being fed in.
The temperature can also be decreased by means of a cooling
program, in which, for example, cooling and holding phases or
different cooling rates may alternate.
[0017] Prior to cooling, the NH.sub.3/CO.sub.2 gas mixture formed
in the reaction is separated off from the liquid melamine and the
CO.sub.2 dissolved in the liquid melamine is reduced by introducing
gaseous ammonia. It is further possible to allow the liquid
melamine, prior to the depressurization, to dwell for from about 5
minutes up to 20 hours at the ammonia partial pressure set.
Preferably, it is allowed to dwell for between 10 minutes and 10
hours, particularly preferably between 30 minutes and 4 hours.
Longer dwell times are also possible if desired.
[0018] The ammonia-containing melamine to be purified is present in
liquid form prior to the depressurization. In the depressurization,
the pressure is rapidly decreased, depending on the initial
pressure set, to a value between 20 bar and about 200 bar,
preferably to between 20 bar and about 150 bar, particularly
preferably to between 20 bar and about 50 bar.
[0019] In the depressurization, the ammonia dissolved in the
melamine escapes, which increases the solidification point of the
melamine then substantially freed from ammonia by up to about
60.degree. C., so that the liquid melamine immediately solidifies,
and the formation of byproducts, in particular melem, is prevented.
On the one hand, owing to the depressurization, the temperature in
the system decreases, but on the other hand, owing to the melamine
solidification, heat of crystallization is released. It is assumed
that the process proceeds approximately autothermally overall.
[0020] It is advantageous if the melamine melt is saturated with
ammonia before the depressurization. However, it is also possible
to carry out the depressurization using a melamine melt not
saturated with ammonia, but the advantage of the melting point
elevation cannot be completely exploited in this case.
[0021] The depressurization can be performed directly in the vessel
or the apparatus into which the liquid melamine was introduced.
However, the depressurization can also be carried out by
transferring or spraying melamine into one or more further vessels
by means of suitable spraying apparatuses. Preferably, in this
case, an ammonia atmosphere is present in the vessel. Furthermore,
it is particularly advantageous to depressurize the melamine into a
vessel in which approximately the same temperature prevails as in
the receptacle from which it is depressurized.
[0022] The then solid melamine can, if desired, be kept at the then
prevailing ammonia partial pressure and the prevailing temperatures
for some further time, for instance for from 1 minute to 20 hours.
Preferably, the solid melamine is allowed to dwell under these
conditions for between 10 minutes and 10 hours, particularly
preferably for between 30 minutes and 3 hours. Preferably, the
temperature in this case should be below about 290.degree. C.
Particularly preferably, the then solid melamine is allowed to
dwell at a temperature between about 280 and 250.degree. C., the
temperature during this period being able either to be kept
constant or to be varied continuously or discontinuously.
Subsequently to this depressurization process or the dwell time,
the then solid melamine can, in any manner and depending on the
technical conditions, be initially cooled to room temperature and
then further depressurized to atmospheric pressure or
simultaneously, or in reverse order, can be further depressurized
and cooled. Preferably, the solid melamine is firstly further
depressurized and then cooled to room temperature.
[0023] The already solid melamine is cooled to room temperature,
for example, by quenching with a cold, liquid medium, for instance
by means of liquid ammonia, by mixing with cold gases, by cooling
by means of heat exchangers, for example by means of a temperature
program, or by simple removal of the heating medium.
[0024] The process of the invention can be carried out, as
required, either in a discontinuous process or in a continuous
process. It is particularly advantageous to carry out the process
of the invention continuously.
[0025] In an advantageous embodiment, after separating off NH.sub.3
and CO.sub.2, the melamine melt is allowed to dwell at an ammonia
pressure of about 70-300 bar, preferably at the prevailing reactor
pressure, the temperature is decreased, with further feed of
ammonia, as close as possible to the solidification point
prevailing at this ammonia partial pressure, then depressurised to
about 50 bar to 20 bar, if appropriate allowed to dwell, and
further depressurized and cooled to room temperature.
[0026] The individual steps of the process of the invention, such
as
[0027] if appropriate separating off an NH.sub.3/CO.sub.2 gas
mixture with
[0028] if appropriate subsequent reduction of dissolved CO.sub.2
content
[0029] if appropriate allowing to dwell and cooling to the
depressurization temperature
[0030] depressurization
[0031] if appropriate allowing to dwell in the solid state
[0032] if appropriate further depressurization to atmospheric
pressure and cooling to room temperature,
[0033] can be carried out, for example, in separate vessels or
apparatuses suitable for the particular step. However, it is also
possible to carry out two or more of these steps in shared
apparatuses. The process procedure must, however, be matched to the
particular conditions.
[0034] In order to determine the dependence of the melamine
solidification point on the prevailing ammonia partial pressure,
appropriate cooling experiments were carried out.
[0035] Melamine is obtained by the process of the invention in
crystalline form or as a powder having a purity of up to greater
than 99.8% and has a markedly decreased content, in particular, of
melem and melam.
EXAMPLES 1-6
[0036] Determination of the Melamine Solidification Point Dependent
on the Ammonia Partial Pressure
[0037] 9.9 g of melamine containing 0.1 g of melem were weighed
into an autoclave together with the amount of ammonia required to
set a defined pressure p, and melted. The reaction mixture was
allowed to dwell at 370.degree. C. for some hours h, in order to
enable establishment of equilibrium. The reaction mixture was then
allowed to cool and the temperature course was monitored, the
solidification point being recognizable by a brief temperature
increase. The process parameters such as pressure, dwell time and
the solidification point (Sp) determined can be seen in Table 1.
The dependence of the melamine solidification point on the
particular prevailing ammonia partial pressure is shown in FIG.
1.
1 TABLE 1 Example p (bar) h Sp (.degree. C.) 1 350 6 294 2 300 6
300 3 250 6 306 4 200 6 317 5 150 6 328 6 110 6 331
EXAMPLES 7-19
[0038] 9.9 g of melamine having a melam content of 1300 ppm, 0.1 g
of melem and the amount of ammonia required to achieve the pressure
p.sub.1 desired prior to the depressurization were introduced into
a laboratory autoclave having a volume of 70 ml. The autoclave was
then brought to a temperature T.sub.1, cooled if appropriate in x
minutes to a temperature T.sub.2 and kept at this temperature for
t.sub.1 minutes. The pressure was then rapidly reduced to a defined
pressure p.sub.2 and then, if appropriate, kept for t.sub.2 minutes
under the then-prevailing reaction conditions.
[0039] When this process was complete, the mixture was abruptly
cooled and depressurized in the water bath and the melamine
obtained was analyzed.
[0040] The process parameters such as pressure p.sub.1 and p.sub.2,
temperature T.sub.1 and T.sub.2, cooling time from T.sub.1 to
T.sub.2 in x minutes, dwell times t.sub.1 and t.sub.2, and the
final content of melem (ME) and melam (MA) can be seen in Table
2.
2TABLE 2 p.sub.1 T.sub.1 x T.sub.2 t.sub.1 p.sub.2 t.sub.2 ME MA
Ex. (bar) (.degree. C.) (min) (.degree. C.) (min) (bar) (min) ppm
ppm 7 300 310 0 310 120 150 0 40 <300 8 250 320 0 320 120 150 0
65 350 9 250 370 60 320 120 35 0 190 400 10 250 370 60 20 120 50 5
80 410 11 250 370 60 320 120 150 5 80 500 12 250 370 60 320 120 150
5 45 310 13 250 370 60 320 30 150 5 25 <300 14 250 370 60 320 10
50 5 65 <300 15 250 370 30 320 10 50 5 185 530 16 250 370 60 320
10 150 5 50 <300 17 250 370 30 320 10 150 5 50 <300 18 250
370 7 320 10 150 5 45 <300 19 200 335 0 335 120 150 0 220
440
EXAMPLES 20-36
[0041] x g of melamine (M.sub.0) having a melam content (MA.sub.0)
of 1300 ppm and y g of melem (ME.sub.0), and the amount of ammonia
required to achieve the pressure p.sub.1 desired prior to the
depressurization, were introduced into a laboratory autoclave A1
having a volume of 100 ml. The autoclave was then brought to a
temperature of 370.degree. C. (T.sub.1) and kept at T.sub.1 for
t.sub.1 minutes. The autoclave was then cooled to a temperature
T.sub.2 in z.sub.1 minutes and kept at this temperature for t.sub.2
minutes.
[0042] In Examples 20-32, subsequently thereto, the melamine
situated in A1 was sprayed into a laboratory autoclave A2 having a
volume of 1000 ml which was kept at a temperature of T.sub.3 and a
pressure p.sub.3.
[0043] In Examples 33 and 34, the temperature T.sub.2 in the
autoclave A1 was decreased to the temperature T.sub.2s in t.sub.2s
minutes. Simultaneously with this, the temperature T.sub.3 in the
autoclave A2 was decreased to the temperature T.sub.2s and the
pressure was set to the value of p.sub.3 and the melamine from
A.sub.1 was sprayed into A.sub.2.
[0044] In Examples 35 and 36, only a portion of the liquid melamine
was sprayed from the autoclave A1 into the autoclave A2, by a valve
in the line between A1 and A2 being briefly opened and closed
again. This kept the pressure drop in A1 and the pressure increase
in A2 low.
[0045] After the product transfer, the temperature T.sub.2 in A1
changed to a value T.sub.2.1, and the pressure p.sub.1 to a value
of p.sub.2. In the autoclave A2, the temperature T.sub.3 changed to
a value T.sub.3.1 and the pressure p.sub.3 to a value
p.sub.3.1.
[0046] The melamine (M.sub.1) remaining in A1 was cooled to a
temperature T.sub.4 in z.sub.2 minutes, then depressurized, rapidly
cooled and analyzed (ME.sub.1, MA.sub.1).
[0047] The melamine (M.sub.2) sprayed into A2 was cooled to a
temperature T.sub.5 in z.sub.3 minutes, depressurized, rapidly
cooled and analyzed (ME.sub.2, MA.sub.2).
[0048] The process parameters such as pressure p.sub.1, p.sub.2,
p.sub.3 and p.sub.3.1, temperature T.sub.1, T.sub.2, T.sub.2.1,
T.sub.2s, T.sub.3, T.sub.3.1, T.sub.4 and T.sub.5, cooling time
z.sub.1, z.sub.2 and z.sub.3 minutes, dwell times t.sub.1, t.sub.2
and t.sub.2s and the initial (M.sub.0) and final (M.sub.1, M.sub.2)
weights of melamine, the initial melem content (ME.sub.0) and the
final contents of melem (ME.sub.1, ME.sub.2) and melam (MA.sub.1,
MA.sub.2) can be seen in Table 3.
3TABLE 3 Autoclave A1 (T.sub.1 = 370.degree. C.) prior to product
transfer Exam- xM.sub.0 yME.sub.0 p.sub.1 t.sub.1 z.sub.1 T.sub.2
t.sub.2 T.sub.2s t.sub.2s ple (g) (g) (bar) (min) (min) (.degree.
C.) (min) (.degree. C.) (min) 20 9.9 0.1 250 0 60 320 10 21 9.9 0.1
250 0 60 315 10 22 9.9 0.1 250 0 60 310 10 23 9.9 0.1 350 0 60 300
10 24 29.7 0.3 250 90 60 320 10 25 19.8 0.2 250 120 60 320 10 26
19.8 0.2 250 120 60 320 10 27 9.9 0.1 300 0 60 315 10 28 9.9 0.1
200 0 60 330 10 29 9.9 0.1 350 0 60 303 10 30 9.9 0.1 350 0 60 310
10 31 9.9 0.1 200 60 60 330 10 32 19.8 0.2 250 120 60 320 10 33 9.9
0.1 250 60 53 320 120 312 24 34 9.9 0.1 250 60 41 330 120 314 32 35
9.9 0.1 265 120 69 316 0 36 9.9 0.1 260 120 59 317 0
[0049] Autoclave A1 after product transfer
4 T.sub.2.1 p.sub.2 M.sub.1 T.sub.4 z.sub.2 ME.sub.1 MA.sub.1
Example (.degree. C.) (bar) (g) (.degree. C.) (min) (ppm) (ppm) 20
307 90 5.5 245 13 20 <300 21 285 85 7.0 RT r 20 <300 22 275
85 8.0 250 14 20 <300 23 270 50 4.0 250 4 <20 <300 24 326
175 22.0 280 14 <20 <300 25 304 70 1.0 280 6 55 490 26 307 80
10.5 280 13 20 <300 27 294 80 3.0 280 12 25 <300 28 314 80
1.2 80 18 <20 380 29 274 60 3.5 250 8 <20 370 30 275 65 1.5
250 4 <20 <300 31 306 50 1.5 280 8 100 800 32 302 65 1.0 280
10 50 630 33 292 80 4.9 300 10 <20 <300 34 295 80 0.8 300 6
<20 <300 35 311 220 3.8 300 6 <50 800 36 -- 235 3.2 300 6
<50 820
[0050] Autoclave A2
5 T.sub.3 p.sub.3 T.sub.3.1 p.sub.3.1 M.sub.2 T.sub.5 z.sub.3
ME.sub.2 MA.sub.2 Ex. (.degree. C.) (bar) (.degree. C.) (bar) (g)
(.degree. C.) (min) (ppm) (ppm) 20 277 52 284 79 3.5 250 12 75
<300 21 280 51 282 76 2.7 RT r 75 600 22 281 52 282 76 1.1 250 8
55 650 23 280 0 280 40 6.0 250 12 60 1100 24 320 6 320 15 3.0 280
15 40 1600 25 300 40 309 68 15.5 280 8 95 360 26 302 50 306 74 8.0
280 11 70 540 27 282 40 285 72 4.5 280 4 20 780 28 302 50 304 72
3.8 280 12 65 650 29 280 17 280 60 5.5 250 10 20 100 30 300 20 300
62 4.5 280 5 25 770 31 298 20 300 48 6.5 280 12 110 1000 32 300 30
305 62 16.0 280 11 45 790 33 312 52 312 78 2.9 280 15 <20
<300 34 314 51 314 76 6.2 280 15 20 300 35 316 53 316 57 2.8 280
15 <20 400 36 280 55 280 -- 3.2 275 3 40 750
[0051] RT to room temperature
[0052] r rapidly
* * * * *