Note: Descriptions are shown in the official language in which they were submitted.
~J i3 ~ 2
METHODS FO~ M~NUFACTURE OF METHYLOLATED CYCLOHEXANE-
CARBOGUANAMINE ~ND ~LKYLETHERIFICATION P~ODUCT THEREOF
~D-~M-~N~-T~ E~ ~=T~
BACKGROUND OF THE IN~ENTION
Field of the Invention
This invention relates to methods for the
manufacture of a methylolated cyclohexanecarboguanamine and
an alkyletherificatlon product thereof and a laminated sheet
using the products. More particularly, it relates to
methods for e~ficiently manufacturing a highly methylolated
cyclohexanecarboguanamine and an alkyletherification product
thereof by improving the conversion of the reaction between
cyclohexanecarboguanamine and a formaldehyde and making
effective use of the formaldehyde and a laminated sheet
using the products.
Descri?tion of the Prior Art
Methods for the production of an methylolated
cyclohexanecarboguanamine resin by the reaction of
cyclohexanecarboguanamine with a formaldehyde have been
known to the art. They are disclosed in JP-B-48-
17,756(1973), U.S. Patent No. 2,859,188, and European Patent
No. 0,292,306, for example. These publications, however,
are short of mentioning a technique for producing a highly
methylolated cyclohexanecarboguanamine by heightening the
conversion of a formaldehyde and effectively utilizing of
formaldehyde.
Concerning melamine and benzoguanamine which are
heretofore known amino compounds, no specific technique
making effective use of a formaldehyde has been known to the
art. This is because highly methylolated products of these
compounds are solid substances sparingly soluble in water at
normal room temperature and are precipitated out of the
reaction system and, consequently, the conversion of a
formaldehyde can be heightened without using any specific
technique. Methods for the production of a highly
methylolated benzoguanamine have been known to the art.
3 ~ 2
They are disclosed in British Patent No. 1,219,950, U.S.
Patent No. 3,091,612, and Journal of Applied Polymer
Science, 13, 555 (1969). These methods invariably rely on a
procedure which comprises causing about 6 mols of 37 wt% of
formalin to react with 1 mol of benzoguanamine, cooling the
resultant reaction solution thereby inducing precipitation
of tetramethylolated benzoguanamine in a solid state, and
separating the precipitate by filtration.
In these methods, the yield of tetramethylolated
benzoguanamine at the end of purification is 79.5%,
indicating that in the reaction of benzoguanamine with a
formaldehyde, the conversion obtained without using any
specific technique is already sufficiently high. Since the
unaltered formaldehyde remains in the aqueous solution after
the reaction, it can be easily put to use again.
When such a method is applied in its unmodified form
to cyclohexanecarboguanamine, however, the number of mols of
formaldehyde added to the resultant methylolated
cyclohexanecarboguanamine is as small as 3.2 on the average
per molecule of the cyclohexanecarboguanamine. Further,
since the methylolated cyclohexanecarboguanamine is in a
liquid state at normal room temperature and possesses high
water solubility, the separation thereof from the reaction
solution is attained only with difficulty. The unaltered
formaldehyde which occurs herein, unlike that which occurs
in the reaction involving the heretofore known
benzoguanamine or melamine, cannot be easily put to use
again. In the production of a methylolated
cyclohexanecarboguanamine, therefore, it has been necessary
to decrease the consumption of a formaldehyde by heightening
the conversion in the reaction of the
cyclohexanecarboguanamine with a formaldehyde.
The technique for heightening the conversion of a
formaldehyde in the reaction of methylolation of
cyclohexanecarboguanamine has never been known to the art.
When the methylolated cyclohexanecarboguanamine is
L~ h~
alkyletherified by the conventional method, the
alkyletherification ratio is 70% at most.
An object of this invention, therefore, i5 to
provide methods for the manufacture of a methylolated
cyclohexanecarboguanamine and an alkyletherified product
thereof, with the conversion in the methylolation of
cyclohexanecarboguanamine heightened and the consumption of
a formaldehyde decreased, and a laminated sheet using the
product mentioned above.
SUMMARY 0~ THE INVENTION
The object described above is accomplished by a
method for the manufacture of a methylolated
cyclohexanecarboguanamine by subjecting a
cyclohexanecarboguanamine to the methylolating reaction with
a formaldehyde while keeping the amount of an alcohol (A)
occurring during the process of the methylolating reaction
below 20% by weight based on the amount of the formaldehyde
and keeping the pH value of the reaction system in the range
of 8 to 13 and the temperature thereof in the range of 50
to 80C between the time the reaction is started and the
time the reaction is completed.
~ Thc ~ee~ furthor a~c-ompli~by~ ar
t ~ manufac tu re of an alky l e th er i fi ed
cyclohex ~ carboguanamine by subjecting the methylolated
cyclohexanec ~ guanamine obtained by the above method to
the alkyletherif ~ reaction with an alcohol (B).
The object i ~ so accomplished by a laminated sheet
produced by a process ~ manufacture which comprises
impregnating a sheetlike artic ~ with a liquid containing a
methylolated cyclohexanecarboguana ~ 3.6 to 4.0 in degree
of methylolation or an ~ l etherified
cyclohexanecarboguanamine 3.6 to 4.0 ~ degree of
methylolation and 90 to 100% in ratio\ Q~f alkyl
etherification and subsequently curing the imp ~ ated
~e~tl-ik~-articlo.
The term "the degree of methylolation" used herein
means the average number of mols of formaldehyde added per
molecule of cyclohexanecarboguanamine and the term "ratio of
alkyletherification" the ratio of the methylol group
undergone alkyletherification~
For a fixed amount of formaldehyde, the method of
this inv e n ti o n y ie l d s a m e t h y l o l a te d
cyclohexanecarboguanamine having a high degree of
methylolation and an alkyletherified product thereof having
a high ratio of alkyletherification with a high productional
efficiency as compared with the conventional methodO It
also allows a decrease in the consumption of the
formaldehyde. The methylolated cyclohexanecarboguanamine
obtained by the method of this invention is favorably used
for molding material, faced board, faced plywood, etc. and
the alkyletherified product obtained by the reaction of the
methylolated cyclohexanecarboguanamine with an alcohol is
likewise used favorably for faced board or faced plywood.
EXPLANATION OF THE PREFERRED EMBODIMENT
We have continued a diligent study in search of the
cause for the low conversion in the reaction of a
cyclohexanecarboguanamine with a formaldehyde effected by
the conventional method, to find that the occurrence of an
alcohol (A) impedes an improvement in the degree of
methylolation. The term "alcohol (A)" as used herein refers
not to an alcohol originating in a formaldehyde but to an
alcohol used as a stabilizer or a solvent for formaldehyde
such as, for example, methyl alcohol, ethyl alcohol, propyl
alcohol, or butyl alcohol. Generally, the content of the
alcohol (A) is calculated by gas chromatographic analysis or
by measurement of specific gravity. The aqueous 37%
~ormalin solution in popular use generally contains about
10% by weight, based on the amount of the aqueous solution,
or about 27% by weight, based on the amount of the
formaldehyde, of methyl alcohol. It is known that the
addition of this alcohol (A) improves the solubility of the
formaldehyde in water and the stability of the aqueous
soluion. It is really surprising to note that the alcohol
(A) of this nature should impede the methylolating reaction.
As disclosed in U.S. Patent No. 2,998,411, for
example, the methylolating reaction of melamine is impeded
by the presence of an alcohol (A). Concerning the cause for
impediment of this reaction, the aforementioned ~.S. patent
gives at column 1, line 63, to column 2, line 22, a
statement to the effect that a methylolated melamine
possessing a low degree of methylolation is precipitated in
the reaction solution in the presence of an alcohol (A) and
the methylolating reaction consequently ceases to proceed.
In the case of the methylolating reaction of
cyclohexanecarboguanamine, the reaction solution forms
absolutely no precipitate in the presence of an alcohol (A).
Thus, the cause for impediment established with respect to
melamine cannot be applied as it is to the methylolating
reaction of cyclohexanecarboguanamine. The cause for the
impediment imposed by an alcohol (A) on the methylolating
reaction of cyclohexanecarboguanamine has not yet been
elucidated. This impediment is explained by a postulate
that since an alcohol (A) is used as the stabilizer for
formalin, the reaction between the stabilized formaldehyde
and cyclohexanecarboguanamine proceeds with difficulty as
compared with the reaction with benzoguanamine. As surmised
from the foregoing explanation, the amount of the alcohol(A)
to be used in the reaction is desired to be small.
Generally, this amount is not more than 20% by weight,
preferably not more than 10% by weight, based on the amount
of the formaldehyde. Though the absolute absence of this
alcohol (A) is ideal, very satisfactory results are obtained
generally when the amount is not more than 5% by weight.
For the production of a highly methylolated
cyclohexanecarboguanamine having a small condensate content,
it is necessary that in the reaction of a
cyclohexanecarboguanamine with a formaldehyde, the pH value
of the reaction system should be kept in the range of 8 to
13 and the temperature thereof in the range of 50 to 80C
between the time the reaction is started and the time it is
completed. If the pH value is smaller than 8 or larger than
13, the reaction of condensation readily proceeds, the pH
value fluctuates heavily between the time the reaction is
started and the time the reaction is completed, and the
adjustment of pH value requires use of a large amount of a
buffer. For the purpose of repressing the reaction of
condensation and decreasing the fluctuation of pH value more
effectively, the pH value is preferable to be kept in the
range of 9 to 11, preferably 9.5 to 1005. If the
temperature is lower than 50C, the reaction of
cyclohexanecarboguanamine with formaldehyde is retarded. If
this temperature is higher than 80C, the reaction of
condensation and the reverse reaction of methylolation
readily proceed, the pH value fluctuates heavily between the
time the reaction is stated and the time it is completed,
and the retention of the pH value in the range of 8 to 13
likewise requires use of a large amount of a buffer. The
use of the buffer in such a large amount consequently
increases the amount of water to be used. The presence of
the increased amount of water is undesirable for the reason
to be given hereinbelow. The temperature is preferable to
be in the range of 55 to 70qC for the purpose of decreasing
the fluctuation of pH value between the time the reaction is
started and the time it is completed and repressing the
reaction of condensation and the reverse reaction of
methylolation.
The improvement in the degree of methylolation aimed
at by the present invention is not attained unless the
amount of an alcohol (A) and the pH value and temperature of
the reaction system are kept in the ranges specified above
during the process of the reaction. When any one of these
conditions deviates from the relevant range, the object of
this invention can no longer be fulfilled. When the amount
of an alcohol (A) is kept within the range thereof but the
pH value or temperature of the reaction system deviates from
the range thereof, for example, the condensate occurs in an
unduly large amount. Conversely, when the pH value or
temperature of the reaction system is kept within the range
thereof but the amount of an alcohol (A) deviates from the
range thereof, the resultant product possesses a degree of
methylolation of only about 3.2.
Incidentally, Example 4 cited in European Patent No.
0,292,306 discloses a reaction using paraformaldehyde and
limiting the amount of an alcohol (A) to 0% by weight based
on the formaldehyde. In this example, there is found a
statement that in the methylolating reaction of a
formaldehyde with cyclohexanecarboguanamine, the pH value of
the reaction system was 8.3 and the tempeture thereof was
90C at the end of the reaction. This example and the
method of manufacture of the present invention differ only
in terms of temperature. In this example, since the
temperature exceeds gooc, the reverse reaction of
methylolation readily proceeds and the degree of
methylolation declines and the pE~ value fluctuates largely
between the time the reaction is started and the time it is
completed and the retention of the pH value in the range of
8 to 13 is attained only with difficulty. In fact, in
Example 4 cited in European Patent No. 0,292,306, the
reaction time at 90C is as brief as 10 minutes. If the
amount of an alcohol (A) to be used and the temperature and
pH value of the reaction system which characterize the
present invention are not wholly satisfied, a highly
methylolated cyclohexanecarboguanamine possessing a small
condensate content can no longer be produced. Absolutely no
mention about the effect of the amount of an alcohol (A) on
the methylolating reaction is found anywhere in European
Patent No. 0,292,306.
We have made a dilgent study in search of a method
for heightening the degree of methylolation, to find that
the effect of this invention is further enhanced by
decreasing the amount of water to be used during the process
of reaction. Though the effect of water on the
methylolating reaction has not yet been fully elucitated, it
is inferred that water accelerates the reverse reaction of
methylolation. The amount of water to be used in the
reaction is preferable to be not more than 100% by weight,
preferably not more than 50% by weight, based on the amount
of formaldehyde.
The water which is present in the reaction system of
the present invention comprises the water used as a solvent
and the water contained in the formaldehyde. In this
invention, the water content in the formaldehyde is regarded
as the balance which remains after the subtraction of the
content of formaldehyde and that of alcohol (A). ~he
expression "80% paraformaldehyde" as used in this invention
means that the paraformaldehyde contains 20% of water.
In improving the conversion of formaldehyde, it is
effective to decrease the amount of an alcohol(A) and that
of water occurring in the reaction system as described
above. When the decrease is excessive, however, it possibly
degrades the stirring effect, impairs the uniformity of
temperature in the reaction system, and prevents the
methylolating reaction from proceeding smoothly. It has
been found that the use of a solvent substantially insoluble
in water in the methylolating reaction brings about an
effect of precluding the disadvantage described above and
promoting the methylolating reaction as well.
The substantially water-insoluble solvent which is
used in the reaction has no particular restriction except
for the requirement that this solvent, when combined with
water to form a binary system, should exhibit that the
solubility of water is not more than 1.0% by weight in this
solvent at 20C and, at the same time, avoid impeding the
reaction of cyclohexanecarboguanamine with a formaldehyde.
This solvent is preferably an aromatic and/or an aliphatic
~ rl "~ f.?`s-,3 ~
hydrocarbon, more preferably an aromatic hydrocarbon, and
still more preferably an alkyl-substituted benzene and/or an
unsubstituted benzene. The solvents which answer the
description include hexanes, heptanes, octanes, nonanes 7
decanes, cyclohexane, benzene, toluene, xylene, ethyl
benzene, and pseudocumene, for example. The xylene is known
to react with formaldehydes as in a xylene-formaldehyde
resin. It is substantially întact, however, under the
conditions involved in the reaction of the present
invention. Though the amount of the solvent to be used is
not specifically limited, it is desirable for the purpose of
enabling the aforementioned effect to be manifested to the
fullest possible extent that the amount should be in the
range of 0.7 to 10 parts, preferably 1.5 to 4 parts, by
weight based on 1 part by weight of the formaldehyde.
The formaldehydes which are effectively usable in
the reaction include paraformaldehyde, trioxane, formalin,
and concentrated formalin, for example. Since the reaction
prefers use of alcohol (A) and water in as small amounts as
possible, it is preferable to use paraformaldehyde or highly
concentrated formalin. The paraformaldehyde proves to be
particularly preferable in respect that it is readily
available on a commercial scale and it is excellent in
stability of storage. When the paraformaldehyde is used, it
is desired to have a particle diameter distribution such
that not less than 90% of the particles thereof pass through
a 32-mesh sieve (JIS standard sieve). If this ratio of 32-
mesh passage is less than 90%, the speed of depolymerization
of paraformaldehyde is lowered, the reaction time is
lengthened, and the degree of methylolation is degraded
under the reaction conditions.
The amount of a formaldehyde to be used is
preferable to be in the range of 2.5 to 10 mols per mol of
cyclohexanecarboguanamine. If this amount is less than 2.5
mols, the reaction system possibly induces precipitation of
monomethylolated cyclohexanecarboguanamine. Conversely, if
r"~ ~J 7 ~
the amount exceeds 10 mols, the excess formaldehyde brings
about substantially no addition to the ratio of
methylolation and represents no efficient use of the
formaldehyde. Particularly, when the methylolation is
required to be performed to such a high degree as to fall in
the range of 3.5 to 4.0, it is preferable to use 5 to 10 mol
times of formalin to cyclohexanecarboguanamine. The use of
paraformaldehyde as a formaldehyde entails the possibility
that the formaldehyde undergoes partial depolymerization and
the paraformaldehyde gains in viscosity to the extent of
impeding uniform stirring during the rise of the
temperature of the reaction system to the reaction
temperature when an alkali is added during the combination
of raw materials. This disadvantage can be eliminated and,
at the same time, the improvement in the degree of
methylolation can be attained by making the addition of an
alkali after the temperature of the reaction system has
reached at least 50C thereby adjusting the pH value in the
range of 8 to 13 and diminishing the depolymerization during
the rise of the temperature.
When the reaction solution is concentrated for the
purpose of expelling water and the solvent therefrom, the
possible formation of a hemiformal group can be repressed by
adjusting the pH value in the range of 8 to 11, preferably 9
to 11.
The methylolated cyclohexanecarboguanamine which is
obtained by the method of this invention possesses a degree
of methylolation preferably in the range of 3.5 to 4.0,
preferably 3.8 to 4Ø
The methylolated cyclohexanecarboguanamine obtained
by the method of this invention gives rise to an
alkyletherified cyclohexanecarboguanamine when it is
alkyletherified by the use of an alcohol (B). By this
method, a highly methylolated and etherified alkyletherified
cyclohexanecarboguanamine can be produced with a relatively
small amount of formaldehyde.
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5~ c )
When a methylolated cyclohexanecarboguanamine of a
low degree of methylolation obt;ained by the conventional
method is used in this case, the ratio of
alkyletherification is as low clS 70% at most. When an
methylolated cyclohexanecarboguanamine of a degree of
methylolation of 3.5 to 4.0 obtained by the method of this
invention is alkyletherified~ the ratio of alkyl-
etherification can be heightened very conspicuously. The
alkyletherified cyclohexanecarboguanamine has the viscosity
thereof lowered and the suitability thereof for the
applications to be specifically described hereinbelow
heightened in proportion as the degree of methylolation and
the ratio of alkyletherification are augmented.
The alkyletherified cyclohexanecarboguanamine which
is obtained by the method of this invention possesses a
degree of methylolation preferably in the range of 3.5 to
4.0 and a ratio of alkyletherification preferably in the
range of 90 to 100%.
For the purpose of producing the alkyletherified
cyclohexanecarboguanamine in a highly etherified state, the
reaction with an alcohol(B) is preferable to be performed
twice as described in U.S. Patent No. 2,998,411, for
example. In this case, after the first reaction is
completed, the resultant reaction solution is concentrated
to expel the unaltered alcohol and water therefrom. The
adjustment of the pH value of the reaction solution in the
range of 8 to 11, preferably 9 to 11, during the course of
the concentration brings about a desirable effect of not
only repressing the possible formation of a hemiformal group
but also enabling the residual formaldehyde to promote the
methylolation to a further extent.
Though the alcohol (B) to be used in effecting the
alkyletherification is not specifically restricted, it is
preferable to be an aliphatic alcohol of 1 to 10 carbon
atoms, preferably an aliphatic alcohol of 1 to 4 carbon
atoms. The amount of this alcohol to be used in each of the
!~? .~ . ? ~ i /?
two reactions is in the range of 5 to 50 mols, preferably 5
to 15 mols, per mol of the methylolated
cyclohexanecarboguanamine. The aliphatic alcohols which
answer the description include methanol, ethanol, n-
propanol, isopropanol, n-butanol, sec-butanol, isobutanol,
heptanol, and octanol, for example~
The reaction temperature during the process of
alkyletherification is generally below 50C. When the
resultant alkyletherified cyclohexanecarboguanamine is
preferable to contain a condensate only in a small
proportion, the reaction temperature is preferably below
35C. By keeping the reaction temperature below 35C, the
proportion of the condensate can be lowered even below 5%.
The alkyletherified cyclohexanecarboguanamine which is
obtained as described above possesses a still lower
viscosity and is used advantageously in various
applications.
The content of the condensate in the alkyletherified
cyclohexanecarboguanamine contemplated by the present
invention represents the area ratio of a dimer and higher-
mers which is determined by gel permeation chromatography as
demonstrated in working examples to be cited hereinbelow.
A laminated sheet is obtained by impregnating a
sheetlike article with a liquid containing the methylolated
cyclohexanecarboguanamine and the alkyletherified
cyclohexanecarboguanamine produced by the method of this
invention and subsequently setting the impregnated sheetlike
article.
The faced board of thermosetting resin using an
methylolated cyclohexanecarboguanamine resin is disclosed in
U.S. Patent No. 4,898,788. The resin thus used in the faced
board is a solid resin and not a liquid resin according to
the technique of this invention. The impregnation of a
sheetlike article with the solid resin as used in U.S.
Patent 4,898,788 necessitates use of an organic solvent.
When the sheetlike article impregnated with this solid resin
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~J~6~
is dried with hot air, the resin possibly separates from the
matrix or gives rise to blisters. In accordance with the
present invention, since the methylolated
cyclohexanecarboguanamine to be used therein retains a
liquid state and exhibits solubility in water at normal room
temperature, it has no use for any specific organic solvent.
When the sheetlike article impregnated with the liquid
methylolated cyclohexanecarboguanamine or alkyletherified
cyclohexanecarboguanamine is dried with hot air, the resin
is perfectly free from such adverse phenomena as separation
from the matrix or formation of blisters.
In the case of a highly alkyletherified
cyclohexanecarboguanamine, no use is found for any solvent
because the viscosity thereof is low. Thus, the sheetlike
article can be impregnated directly with this product.
The method to be adopted for the production of a
laminted sheet by the use of an methylolated
cyclohexanecarboguanamine or alkyletherified
cyclohexanecarboguanamine of this invention which is in a
liquid state at normal room temperature has no particular
restriction. The production may be carried out by any of
such conventional methods as disclosed in U.S. Patent No.
4,898,788, for example.
The following methods are typical examples.
(1) A method which comprises impregnating a
sheetlike article with the methylolated
cyclohexanecarboguanamine or alkyletherified
cyclohexanecarboguanamine and thermally setting the
impregnated sheetlike article under application of pressure.
(2) A method which comprises superposing two or
more such impregnated sheetlike articles and thermally
setting the superposed sheetlike articles under application
of pressure.
(3) A method which comprises superposing at least
one such impregnated sheetlike article and a sheetlike
article impregnated with another thermosetting resin
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composition and/or at least one sheetlike article
impregnated with a thermoplast ic resin composition and
thermosetting the super-posed sheetlike articles under
application of pressure.
(4) A method which comprises thermosetting at least
one such impregnated sheetlike ar ticle under application of
pressure thereby preparing a r esin-impregnated sheetl ike
layer and laminating this resin-impregnating sheetlike layer
through the medium of a suitable adhesive agent with at
least one sheetlike article produced by impregnating with
and setting another thermosetting resin composition and/or
at least one sheetlike article impregnated with a
thermoplastic resin.
(5) A method which comprises pasting at least one
such impregnated sheetlike article to a substrate and
thermosetting the resultant composite sheet under
application of pressure.
(6) A method which comprises superposing at least
one such impregnated sheetlike article, a sheetlike article
impregnated with another thermosetting resin composition,
and/or at least one sheel;like article impregnated with a
thermoplastic resin composition and thermosetting the
resultant superposed sheets under application of pressure.
T h e a m o u n t o f t h e m e t h y l o l a t e d
cyclohexanecarboguanamine or alkyletherif ied
cyclohexanecarboguanamine to be used in impregnating the
sheetlike article is in the range of 70 to 150% by weight,
preferably 80 to 1407~ by weight, based on the amount of the
sheetlike article.
The sheetlike article to be used in the production
of the laminated sheet has no particular restriction except
for the sole requirement that it should be a sheetlike
article capable of being easily impregnated with a liquid
substance. Paper and cloth are desirable sheetlike articles
in respect that they are readily available commercially,
capable of easy inscription with any desired pattern, and
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- s i~ -
capable of easily producing a faced board or faced plywood
excelling in quality.
During the process of thermal setting, a setting
catalyst may be added as occasion demands to promote the
setting. The setting catalyst is not particularly defined
but may be any of the conventional setting catalysts fit for
thermosetting resinsO Examples are paratoluenesulfonic acid
and ammonium chloride.
The substrate may be any of various materials
without reference to the choice between natural and
synthetic products or the choice between inorganic and
organic products. The substrates which are advantageou~ly
usable herein include veneer, rigid fiber board, and
particle board, for example.
The other thermosetting resins than the methylolated
cylohexanecarboguanamine and alkyletherified
cyclohexanecarboguanamine which are effectively usable in
the production of the laminated sheet include alkyd resin,
phenol resin, xylene resin, toluene resin, aminoaldehyde
resin, and unsaturated polyester resin, for example. The
thermoplastic resins which are effectively usable herein
include homopolymers and copolymers of vinyl chloride, vinyl
acetate, styrene, for example.
Now, this invention will be described more
specifically below with reference to working examples which
are intended to be illustrative of and not in any sense
limitative of the spirit of this invention.
The data of '~1H-NMR," "high-speed liquid
chromatography (hereinafter referred to as HPLC)," and "gel
permeation chromatography (hereinafter referred to as GPC)
given in the working examples are those determined by the
following methods.
(1) Determination of lH-NMR
This property was determined by using a test tube
containing the solution of a given sample in dimethyl
sulfoxide-d6 or chloroform-d
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by the use of an instrument produced by Varian Corp
and marketed under product code of "XL~300."
(2) Determination of HPLC
Apparatus - Instrument produced by Shimadzu
Seisakusho Ltd. and marketed under product code of "LC-6A"
Column - Product of Shimadzu Technoresearch K.K.
marketed under product code of "ODS-M"
Wavelength for detection - 210 nm
Developing solvent - Mixed solvent of aqueous 0.1
wt% phosphoric aeid solution/acetonitrile
(3) Determination of GPC
Apparatus - Instrument produced by Toso K.K. and
marketed under product code of "HLC-8020"
Column - Product of Toso K.K. marketed under product
code of TSK 2000 HXL + TSK 3000 HXL
Means of detection - RI detector
Developing solvent - Tetrahydrofuran
Column temperature - 40C
Example 1
In a three-necked flask having an inner volume of
300 ml and provided with a stirrer, a reflux condenser, and
a thermometer, 19.3 g (100 m.mols) of
cyclohexanecarboguanamine, 19.6 g (600 m.mols) of granular
92% paraformaldehyde, 14.6 g of water, and 2.7 g of methyl
alcohol (the amount of the water in the reaction system
inclusive of the water in the paraformaldehyde was 16.2 g,
accounting for 90% by weight of formaldehyde, and the amount
of methyl alcohol accounts for 15% by weight of
formaldehyde) were mixed. The resultant reaction solution
was adjusted to pH 10 by the addition of an aqueous sodium
hydroxide solution and then simultaneously stirred and
heated to 60C. It was then further stirred at 60C for one
hour with the pH value thereof kept at 10 ~ 0.5. When it
wa~ subsequently cooled to room temperature, there was
obtained a transparent homogeneous liquid. By HPLC, the
reaction solution was found not to contain unaltered
3 !~
cyclohexanecarboguanamine. By lH-NMR analysis, it was found
to have attained addition of an average of 3.58 formaldehyde
molecules per molecule of cyclohexanecarboguanamine.
During the process of the reaction,
cyclohexanecarboguanamine and paraformaldehyde were
uniformly dissolved after the elapse of about 10 minutes
following the heating up to 60C. Thereafter, no solid
substance was precipitated in the reaction solution.
Example 2
The procedure of Example 1 was repeated, except that
the amount of methyl alcohol was changed to 0.9 g (an amount
accounting for 5% by weight based on the amount of
f`ormaldehyde). The methylolated cyclohexanecarboguanamine
consequently obtained was found to have attained addition of
an average of 3.65 formaldehyde molecules per molecule of
cyclohexanecarboguanamine.
Example 3
The procedure of Example 1 was repeated, except that
the addition of methyl alcohol was omitted. The
methylolated cyclohexanecarboguanamine was found to have
attained addition of an average of 3.77 formaldehyde
molecules per molecule of' cyclohexanecarboguanamine.
Example 4
The procedure of Example 1 was repeated, except that
the amount of water was changed to 25.4 g (the total amount
in the reaction solution was 27 g, or 150% by weight ba~ed
on the amount of formaldehyde) and the addition of methyl
alcohol was omitted. The methylolated
cyclohexanecarboguanamine consequently obtained was found to
have attained addition of an average of 3.55 formaldehyde
molecules per molecule of cyclohexanecarboguanamine.
Example 5
The procedure of Example 1 was repeated, except that
the amount of water was changed to 5.6 g (the total amount
of water in the reaction solution was 7.2 g, or 40~ by
weight based on the amount of formaldehyde) and the addition
/ I ~ ,' ,s ~ ~J ~
of methyl alcohol was omitted. The methylolated
cyclohexanecarboguanamine consequently obtained was found to
have attained addition of an average of 3.80 formaldehyde
molecules per molecule of cyclohexanecarboguanamine.
Example 6
In a three-necked flask having an inner volume of
300 ml and provided with a stirrer, a reflux condenser, and
a thermometer, 19.3 g (100 m.mols) of
cyclohexanecarboguanamine, 19.6 g (600 m.mols) of granular
92% paraformaldehyde, and 40.0 g of toluene (the amount of
the water in the reaction solution inclusive of the water in
the paraformaldehyde was 1.6 g, or 9% by weight based on the
amount of formaldehyde) were mixed. The resultant reaction
solution was adjusted to pH 10 by the addition of an aqueous
sodium hydroxide solution and then simultaneously mixed and
heated to 60C. It was then further stirred at 60C for one
hour, with the pH value kept at 10 + 0.5. When it was
cooled to room temperature, it was separated into two
layers, the upper layer of toluene and the lower layer of
methylolated cyclohexanecarboguanamine. By HPLC analysis,
the lower layer was found to contain no unaltered
cyclohexanecarboguanamine. By 1H-NMR analysis, the reaction
solution was found to have attained addition of an average
of 3.85 formaldehyde molecules per molecule of
cyclohexanecarboguanamine. During the course of this
reaction, cyclohexanecarboguanamine and paraformaldehyd were
uniformly dissolved after the elapse of about 30 minutes
following the heating up to 60C. Thereafter, the reaction
solution formed no solid precipitate. The toluene layer at
the end of the reaction was found to contain substantially
no methylolated cyclohexanecarboguanamine.
Example 7
The procedure of Example 6 was repeated, except that
20.0 g (600 m.mols) of powdered 90% paraformaldehyde having
a particle diameter distribution such that 93% of the
particles passed through a 32-mesh sieve was used instead as
-18-
a paraformaldehyde (the amount of the water in the reaction
solution was 2.0 g of the water present in the
paraformaldehyde 9 accounting for 11% by weight based on the
amount of formaldehyde). The methylolated
cyclohexanecarboguanamine consequently obtained was found to
have attained addition of an average of 3.88 formaldehyde
molecules per molecule of cyclohexanecarboguanamine.
Example 8
The procedure of Example 6 was repeated, except that
the adjustment of the pH value of the freshly prepared
reaction solution was omitted and, after therise of the
reaction temperature to 60C, the reaction solution was
adjusted to pH 10 by the addition of an aqueous sodium
h ydroxide so lu tion. T h e me thy l ol ated
cyclohexanecarboguanamine was found to have attained
addition of an average of 3.87 formaldehyde molecules per
molecule of cyclohexanecarboguanamine.
Example 9
The procedure of Example 3 was repeated, except that
the pH value to which the reaction solution was adjusted was
changed from 10 + 0.5 to 8.5 + 0.5. The methylolated
cyclohexanecarboguanamine consequently obtained was found to
have attained addition of an average of 3.70 formaldehyde
molecules per molecule of cyclohexanecarboguanamine.
Control l
The procedure of Example 1 was repeated, except that
the amount of methyl alcohol was changed to 5.4 g (30% by
weight based on the amount of formaldehyde).
The methylolated cyclohexanecarboguanamine
consequently obtained was found to have attained addition of
an average of 3.33 formaldehyde molecules per molecule of
cyclohexanecarboguanamine.
Control 2
The procedure of Example 1 was repeated, except that
48.6 g (600 m.mols) of 37% formalin was used as a
formaldehyde and the addition of water and methyl alcohol
-19-
~ ~ o~ ;f,"
was omitted (the water in the reaction solution was 25.8 g,
or 143% by weight based on the amount of formaldehyde and
methyl alcohol contained in the formalin was 4.9 g, or 27%
by weight based on the amount of formaldehyde). The
methylolated cyclohexanecarboguanamine consequently obtained
was found to have attained addition of an average of 3.20
formaldehyde molecules per mol ecule of
cyclohexanecarboguanamine.
Control 3
In a three-necked flask having an inner volume of
300 ml and provided with a stirrer, a reflux condenser9 and
a thermometer, 19.3 g (100 m.mols) of
cyclohexanecarboguanamine, 22.5 g (600 m.mols) of 80%
paraformaldehyde, 22.5 g of water, and 0.12 g of an aqueous
10 wt% sodium carbonate solution were mixed. The amounts of
methyl alcohol and water contained in the resultant solution
were respectively 0% by weight and 150% by weight based on
the amount of formaldehyde. This solution was
simultaneously stirred and heated to 90C. It was then
stirred at 90C for 10 minutes. The methylolated
cyclohexanecarboguanamine consequently obtained was found to
have attained addition of an average of 3.24 formaldehyde
molecules per molecule of cyclohexanecarboguanamine.
Example 10
Th e so lu tio n o f m e t h y l o l a te d
cyclohexanecarboguanamine obtained in Example 5 was adjusted
to pH 10 by the addition of an aqueous sodium hydroxide
solution and then subjected to vacuum concentration at 60C
under 60 mmHg. The resultant viscous liquid was mixed with
10 mols, per mol of methylolated cyclohexanecarboguanamine,
of methyl alcohol. The produced mixture was adjusted to pH
2.8 by the addition of concentrated nitric acid and then
stirred at 40C for two hours. The resultant reaction
solution was adjusted to pH 10 by the addition of an aqueous
NaOH solution, subjected to vacuum concentration at 60C
under 60 mmHg, again mixed with methyl alcohol, adjusted to
-20-
~J'3~
pH 2.8 by the addition of concentrated nitric acid, and
further stirred at 40C for two hours.
The produced reaction solution was neutralized with
an aqueous NaOH solution and subjected to vacuum
concentration at 60C under 60 mmHg, to obtain an
alkyletherified cyclohexanecarboguanamine. By 1H-NMR
analysis, this alkyletherified cyclohexanecarboguanamine was
found to have a degree of methylolation of 3.92 and a ratio
of etherification of 98%. By GPC analysis, it was found to
contain 7% of condensate in RI area ratio.
Example 11
The procedure of Example 10 was repeated, except
that the solution of methylolated cyclohexanecarboguanamine
obtained in Example 5 was neutralized with concentrated
nitric acid and then concentrated. By 1H NMR analysis, the
resultant alkyletherified cyclohexanecarboguanamine was
found to have a degree of methylolation of 3.80 and a ratio
of etherification of 97%. By GPC analysis, it was found to
contain 9% of condensate in RI area ratio.
Example 12
Th e s olutio n o f m e t h y l o l a t e d
cyclohexanecarboguanamine obtained in Example 5 was again
adjusted to pH 10 by the addition of an aqueous NaOH
~olution and subjected to vacuum concentration at 60C under
60 mmHg. The resultant viscous liquid was mixed with 10
mols, per mol of methylolated cyclohexanecarboguanamine, of
methyl alcohol, adjusted to pH 2.8 by the addition of
concentrated nitric acid, and then stirred at 40C for two
hours. The produced reaction solution was neutralized to pH
7 by the addition of an aqueous NaOH solution, subjected to
vacuum concentration at 60C under 60 mmHg, mixed with
methyl alcohol, adjusted to pH 2.8 by the addition of
concentrated nitric acid, and stirred at 40C for two hours.
The reaction solution consequently obtained was neutralized
by the addition o~ an aqueous NaOH solution and subjected to
vacuum concentration at 60C under 60 mmHg, to produce
-21-
alkyletherified cyclohexanecarboguanamine. By lH-NMR
analysis, this alkyletherified cyclohexanecarboguanamine was
found to possess a degree of methylolation of 3.72 and a
ratio of etherification of 96~. By GPC analy3is, it was
found to contain 9% of condensate.
Example 13
The procedure of Example 10 was repeated, except
that the two reactions of etherification were both carried
out at 30C. By 1H-NMR, the resultant alkyletherified
cyclohexanecarboguanamine was found to have a degree of
methylolation of 3.92 and a ratio of etherification of 98%.
By GPC analysis, it was found to contain 3% of condensate.
Example 14
Th e s o lu tio n o f m e t h y l o l a te d
cyclohexanecarboguanamine obtained in Example 7 was adjusted
to pH 10 by the addition of an aqueous sodium hydroxide and
subjected to vacuum concentration at 60C under 60 mmHg.
The resultant viscous liquld was mixed with water to obtain
an aqueous 50 wt% methylolated cyclohexanecarboguanamine
solution. lO0 g of this aqueous solution was neutralized,
adjusted to pH 7, and mixed with 0.8 g of p-toluenesulfonic
acid and 0.7 g of lauric acid. A faced sheet 0.2 mm in
thickness and 120 g/m2 in basis weight was impregnated with
the resultant and dried in draft at room temperature. The
air-dired faced paper was dried in hot air at 100C for 15
minutes, to obtain a faced paper (1) impregnated with 120 +
5% of methylolated cyclohexanecarboguanamine.
This faced paper (1) was perfectly free from such
adverse phenomena as resin separation and formation of
blisters and was easy to handle. This faced paper (1), a
phenol-impregnated kraft paper 0.3 mm in thickness and 242
g/m2 in basis weight, and an 80-count white velvet cloth
impregnated with vinyl chloride resin were superposed and
subjected to thermocompression bonding with the aid of a
chromium-plated specular plate under the conditions of 150C
and 25 kg/cm2, to obtain a faced sheet (1).
~ ~ 3 ~ 2
As shown in Table 1, this faced sheet (1) was not
inferior at all in quality to a faced sheet using an
methylolated cyclohexanecarboguanamine resin.
Example 15
A faced paper 0.2 mm in thickness and 120 g/m2 in
basis weight was impregnated with a liquid obtained by
mixing 50 g of the alkyletherified cyclohexanecarboguanamine
obtained in Example 10 with 2.5 g of p-toluenesulfonic acid
and 0.7 g of lauric acid. The impregnated faced paper was
dried in draft at room temperature. The faced paper was
dired with hot air at 100C for 30 minutes, to obtain a
faced paper (2) impregnated with 120 ~ 5~ of
alkyletherified cyclohexanecarboguanamine. This faced paper
(2) was perfectly free ~rom such adverse phenomena as resin
separation and formation of blisters and was easy to handle.
The faced paper (2~, a phenol-impregnated kraft
paper 0.3 mm in thickness and 242 g/m2 in basis weight, and
an 80-count white velvet cloth impregnated with vinyl
chloride resin were superposed and subjected to
thermocompression bonding with the aid of a chromium-plated
specular plate under the conditions of 150C and 25 kg/cm2,
to obtain a faced sheet (2).
As shown in Table 1, this faced plate (2) was not
inferior at all in quality to the faced plate using an
methylolated cyclohexanecarboguanamine.
Control 4
In a three-necked flask having an inner volume of
300 ml and provided with a stirrer, a reflux condenser, and
a thermometer, 19.3 g (100 m.mols) of
cyclohexanecarboguanamine and 24.5 g (302 m.mols) of an
aqueous 37% formalin solution were mixed and the resultant
reaction solution was adjusted to pH 8.5 by the addition of
an aqueous 10% sodium carbonate solution. The reaction
solution was simultaneously heated and stirred at 90C for
two hours, then heated at 100C for four hours to promote
condensation and, at the same time, expel water and the
-23-
unaltered formaldehyde, and further heated to 120G to expel
the residual water and unalterecl formaldehyde and obtain a
solid methylolated cyclohexanecarboguanamine resin intended
for comparison. This comparison grade methylolated
cyclohexanecarboguanamine resin was found to have a degree
of methylolation of 2.5.
A resin solution for comparison was prepared by
combining 50 parts by weight of the comparison grade
methylolated cyclohexanecarboguanamine, 1.0 part by weight
of paratoluenesulfonic acid, 0.75 part by weight of lauric
acid, 40 parts by weight of methanol, and 10 parts by weight
of toluene. A faced paper 0.2 mm in thickness and 120 g/m2
in basis weight was impregnated with the resin solution,
dried in draft at room temperature, and dried with hot air
at 100C for 20 minutes, to obtain an impregnated faced
paper intended for comparison. In this comparison grade
impregnated faced paper, the resin lodged therein partially
formed blisters and was liable to separate from the matrix
unless the faced paper was handled advertently.
This comparison grade impregnated faced paper, a
phenol-impregnated kraft paper 0.3 mm in thickness and 242
g/m2 in basis weight, and an 80-count white velvet cloth
impregnated with vinyl chloride were superposed and
subjected to thermocompression bonding by the use of a
ohromium-plated specular plate under the conditions of 150C
and 25 kg/cm2, to obtain a faced sheet (1) intended for
comparison. The properties of this comparison grade faced
sheet are shown in Table 1.
-24-
2~2~ ~
Table l
Example Control
Test for evaluation 14 15
Surface hardness O O O
Lightfastness O O O
Waterproofness O O O
Stain resistance O O O
Resistance to cracking O O O
Resistance to chemicals O O O
Table 1 shows the results of evaluation of the
indicated properties performed on the faced sheets (1) and
(2) and the comparison grade faced sheet (1) obtained
respectively in Examples 14 and 15 and Control 4. The
properties were rated on the following scales.
The properties suffixed by (J) represent those
tested in accordance with JIS K6902 (1977).
Surface hardness - This property was determined by
subjecting a sample to a scratch hardness A test specified
for JAS special plywood. The results were rated on the two-
point scale, wherein stands for an acceptable product and x
for a rejectable product.
Lightfastness - This property was determined by
exposing a sample to the radiation in a carbon arc fade
tester for 200 hours to find degree of discoloration, ~b
(lab). The results were rated on the three-point scale,
wherein O stands for less than 0.5, ~ for not less than
0.5 and less than 3, and X for not less than 3.
Waterproofness (J) - This property was determined
by immersing a sample in boiling water to find the degree of
resistance to boiling. The results were rated on the two-
-25-
2 ~ 2
point scale, wherein O stands for absencee of interlayer
separation and X for presence thereof.
Stain resistance (J) - This property was determined
by subjecting a sample to a test for staîn resistance. The
results were rated on the three-point scale, wherein O
stands for absence of change, ~ for presence of smear
readily removable by rubbing with dry cloth or for presence
of smear which slightly remained after rubbing with dry
cloth, and X for presence of heavy smear.
Resistance to cracking - This property was
determined by punching a hole in a sample and examining the
appearance of the sample. The results were rated on the
three-point scale, wherein O stands for absence of change,
~ for presence of burrs along the edge of the hole, and X
for presence of chippings, cracks, or separation.
Resistance to chemicals - This property was
determined by subjecting a sample to the alkali-resistance
test and the acid-resistance test specified for JAS special
plywood. The results were rated on the two-point scale,
wherein O stands for absence of change and X for presence
of change.
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