Note: Descriptions are shown in the official language in which they were submitted.
1140~4S
The present invention relates to novel triisocyanate compounds,
which can be converted to plastics, particularly polyurethane resins with im-
proved weatherability, especially excellent polyurethane coatings of a sol-
vent-free or high-solids type.
Among isocyanate compounds employable as a raw material for poly-
urethanes, aromatic isocyanates such as tolylene diisocyanate (TDI) and
~iphenylmethane diisocyanate (MDI) are utilized in large quantities. However,
polyurethanes derived from these aromatic isocyanate compounds suffer from the
serious defect of their tendency to yellow with elapse of time and such defect
represents one of the restrictions on their field of application.
A great variety of efforts have so far been made to produce poly-
urethane compounds with improved non-yellowing properties, and it has been
attempted to apply to polyurethane resins aliphatic or aromatic-aliphatic
polyisocyanates, such as hexamethylene diisocyanate (HDI), xylylene diisocyan-
ate (XDI), hydrogenated xylylene diisocyanate (H6XDI), hydrogenated diphenyl-
methane diisocyanate (H12MDI), isophoron diisocyanate (IPDI) and lysine
diisocyanate ester (LDI). Nevertheless, these have a fewer number of func-
tional groups per molecule and a high vapor pressure at ambient temperature,
and are therefore required to be converted to adducts with polyfunctional
alcohols, amines, water, etc. or those among isocyanates such as dimers,
trimers and carbodiimides, when these are applied as coatings. However, these
adducts, necessitating consumption of isocyanate groups for the addition reac-
tion, possess a reduced content of isocyanate groups available for urther
reaction, with increase in viscosity, which makes it very difficult to be con-
verted to the solvent-free or high-solids coatings recently being strongly de-
manded in view of strengthened pollution control. In order to lower the con-
tent of isocyanate monomer which presents a hygienically serious problem in
--1--
~4~45i
the case of such adducts at working sites, complex technologies and costly
production facilities are required.
Consequently, strong demand exists for polyisocyanates which elimin-
ate the defects of isocyanate compounds currently employed and which can
afford polyurethane resins with superior weatherability, further being con-
vertible to solvent-free or high-solids coatings.
The present inventors, have conducted extensive and thorough re-
search and investigation for the purpose of obtaining a polyisocyanate ful-
filling such requisites with the use of readily avai~able and relatively low-
priced starting materials.
Thus, one aspect of the present invention provides a triisocyanate
compound of the general formula (I):
CH2NCO
~ (I)
OCNH2C ~ CH2NCO
wherein ~ is ~ or ~ .
A further aspect of the invention provides a process for producing a
triisocyanate compound of the general formula (I):
Cl'12NCO
(I)
OCNCH2 CH2NCO
wherein ~ is as defined above, which comprises reacting a triamine com-
pound of the general formula (II):
11D~0~5
CH2NH2
~ (II)
NH2C112 C112NH2
wherein ~ as defined above, or a salt thereof, with phosgene.
Another aspect of the invention provides a process for producing a
polyurethane resin, which comprises reacting a triisocyanate compound of the
general formula ~
CH2NCO
OCNCH2 C~12NCO
wherein ~ is ~ or ~ with an active hydrogen compound.
The above-mentioned triisocyanates of the general formula (I) are
novel compounds which have not been described in the known literature.
The compound of the general formula ~I) wherein ~ is ~ ,
is 1,3l5-trislisocyanatomethyl)benzene (hereinafter referred to sometimes as
"MTI"), while the one wherein ~ is ~ , is 1,3,5-trislisocyanato-
methyl)cyclohexane Ihereinafter referred to sometimes as "H6MTI"), and these
can be produced by phosgenating the corresponding triamine compounds (II), ie.
1,3,5-tris(aminomethyl)benzene Ihereinafter referred to sometimes as "MTA" and
1,3,5-trislaminomethyl)cyclohexane Ihereinafter referred to sometimes as
"H6MTA"), respectively.
Phosgenation of the triamines (II) can be carried ou~ in accordance
with procedures conventional per se. Of these, one is the so-called cold-hot
phosgenation, which comprises adding the starting triamine compound or a solu~on
~14~145
of said triamine compound in an organic solvent dropwise, under stirring, to
cooled liquid phosgene or a solution of phosgene in an organic solvent, and
elevating the reaction temperature while feeding phosgene to allow the reac-
tion to proceed and go to completion. Another procedure is the process which
comprises adding an organic solvent to a salt of the starting triamine to form
a slurry or adding an acid to a solution of the triamine in an organic solvent
to obtain a slurry of the triamine salt, and gradually elevating the tempera-
ture while feeding phosgene to the slurry to allow the phosgenation reaction
to proceed and go to completion.
The starting triamines with a high degree of purity may be utilized,
although the starting triamines containing a small amount of impurities by-
produced during production of said triamines can also be used.
As examples of organic solvents useful in the phosgenation reaction
may be mentioned aromatic hydrocarbons, halogenated aromatic hydrocarbons,
halogenated aliphatic hydrocarbons, halogenated alicyclic hydrocarbons, etc.,
and, among these> halogenated aromatic hydrocarbons such as chlorobenzene and
o-dichlorobenzene are desirable. The salts of the triamines which are oper-
able include acetic acid salt, hydrochloric acid salt, sulfuric acid salt,
carbamic acid salt and the like, and preferred among others is the carbamic
acid salt formed by reacting the triamine with carbon dioxide gas. Phosgene
can be used either in the gaseous or liquid form, and phosgene dimer (tri-
chloromethyl chloroformate) which is regarded as a precursor of phosgene in
this industrial field can be used in place of phosgene.
Referring to the temperature in the reaction between the triamine
compound (II) and phosgene, a too elevated temperature results in formation of
a larger amount of by-products, while a too low temperature leads to a lowered
reaction rate, and it is desirable to select the reaction temperature in the
--4--
~140~45
range of from -20 to 180C.
Excessive phosgene and reaction solvent are removed from the reac-
tion solution when the phosgenation is completed in this manner, and vacuum
distillation is then effected, thus resulting in the desired triisocyanate
compound ~I) in a high purity.
The above-mentioned triamine compounds of the general formula ~II)
are also novel compounds which have not been described in the known litera-
tureJ and can be produced, for example, by the procedure to be described be-
low.
Thus, 1,3,5-tris(aminomethyl)benzene (MTA) can be obtained by hydro-
genating, for example, 1,3,5-tricyanobenzene (hereinafter referred to some-
times as "MTN") in the presence of a catalyst, while H6MTA can be obtained by
hydrogenating MTA in the presence of a catalyst or by subjecting MTN, simul-
taneously in the presence of a catalyst, to hydrogenation of the cyano group
and the nuclear reduction of the benzene ring.
The production of MTA by hydrogenation of MTN is advantageously con-
ducted in the liquid phase in the presence of hydrogen, whereby the use of a
solvent provides good results.
As the solvent may be used, solely or as a mixture of two or more
kinds, aromatic hydrocarbons such as benzene, toluene and xylene, alcohols
such as methanol, ethanol, propanol, isopropanol and isobutanol, ethers such
as dioxane and tetrahydrofuran, and cther solvents inert under the reaction
conditions such as water and liquid ammonia, although the solvents based on
alcohols or aromatic hydrocarbon-alcohol mixtures, which allow a reduction in
the catalyst amo~nt with a lessened decrease in the yield, are preferably
used. As to the amount of the solvent, which is not specifically restricted,
0.5 to 10 times by volume, preferably 1 to 6 times by volume relative to the
--5--
11401~S
starting trinitrile compound provides satisfactory results. Naturally, the use
of larger quantities of the solvent does not interfere greatly with the reaction,
but use of a large amount of solvent is not economical from a commercial point
of view. By adding at the same time a basic substance, for example a hydroxide
or alcoholate of an alkali metal, such as lithium hydroxide, sodium hydroxide,
potassium hydroxide, sodium methylate or sodium ethylate, at a rate of 0.05 to
40% by weight, preferably 0.5 to 20% by weight, based on the starting trinitrile,
there may be obtained advantages such as a decreased addition amount of catalystand shortened reaction time. In conducting the hydrogenation, use is generaliy
made of hydrogen, and it is advisable to conduct the reaction in a pressure
vessel such as an autoclave in the case of a higher applied reaction pressure.
The reaction pressure is generally in the region of 30 to 300 kg/cm G, prefer-
ably in the region of 30 to 150 kg/cm2G, whereas the reaction temperature is
generally in the range of -10 to 150C, preferably in the range of 40 to 120~C.
In carrying out the hydrogenation, it is normally desirable to use a catalyst.
As examples of the catalyst may be mentioned Raney cobalt, Raney nickel, Raney
nickel-chromium, platinum, palladium, ruthenium and rhodium. These are used
singly or as a mixture of two or more kinds and Raney nickel-chromium, among
others, produces the preferable results. By selecting a suitable solvent
system and an additioll amount of an alkali, there may be produced such conditions
as may bring about a relatively small decrease in yield, even when a lower-priced
Raney-nickel catalyst is utilized or the amount of added catalyst is reduced.
MTA is in the form of colorless crystals at ambient temperature and,
upon heating at about 50C, turns into a colorless, clear liquid. After being
purified under normal conditions, it has a melting point of 49 to 51C and a
boiling point of 136 to 139C/0.4 mmHg.
H6MTA may be obtained by hydrogenating MTA or hydrogenating ~fT~.
- 6 -
~1~014~;
The hydrogenation of MTA is genera:lly conducted in the liquid phase in
the presence of hydrogen, with a solvent being employed if necessary. As the
solvent may be employed, singly or as a mixture of two or more kinds, for ex-
ample, water, ethanol, methanol, propanol, isopropanol, isobutanol, dioxane,
acetic acid, tetrahydrofuran, etc., although water is advantageous in terms of
cost and an alcohol-water mixed solvent, in allowing a reduction in the amount
of catalyst with a minimal decrease in the yield, is preferred. Among the
reaction conditions selected, the solvent is not necessarily the requisite one.
Yet, when a solvent is used, 0.05 to 10 times by volume, preferably 0.1 to 5
times by volume, of the starting MTA may provide satisfactory results. By add-
ing 0.05 to 20% by weight~ preferably 0.1 to 10% by weight, relative to MTA, of
a basic substance, for example, a hydroxide or carbonate of an alkali metal or
alkali earth metal, such as lithium hydroxide, sodium hydroxide, potassium
hydroxide, calcium hydroxide, barium hydroxide or sodium carbonate, there may
be obtained more desirable results. In conducting the hydrogenation, use is
generally made of hydrogen gas, while a reaction vessel is not specifically
limited in design and construction, but should withstand the reaction conditions,
although it is advisable to conduct the reaction in a pressure vessel such as
an autoclave in the case of a higher applied reaction pressure. The reaction
pressure is generally in the region of 5 to 300 kg/cm2G, preferably in the region
of 5 to 150 kg/cm G, whereas the reaction temperature is generally in the range
of -10 to 200C, preferably in the range of 50 to 150C. In carrying out the
hydrogenation, it is normally desirable to use a catalyst. As examples of the
catalyst may be mentioned Raney nickel,Raney nickel-chromium, pallidium, platinum,
rhodium and ruthenium. These catalysts are used singly or as a mixture of two
or more kinds, and, as the case may be, supported on a carrier, such as activated
carbon, silica gel, alumina, diatomaceous earth or pumice, to obtain more desir-
1~40145
able catalysts. Among these, a ruthenium catalyst is preferred because it
allows a reduction in the amount of added catalyst with a minimal decrease in
the yield, especially when water containing a small amount of an alkali metal
hydroxide or carbonate, alcohol or a mixture thereof is employed as solvent.
H6MTA can also be directly obtained through hydrogenation of MTN.
In hydrogenating MTN, there may be produced more desirable results by conducting
the liquid-phase reaction in the presence of hydrogen and employing a solvent.
As examples of the solvent may be mentioned aromatic hydrocarbons such as
benzene, toluene and xylene, alcohols such as methanol, ethanol, propanol, iso-
propanol and isobutanol, ethers such as dioxane and tetrahydrofuran, and others
inclusive of acetic acid, liquid ammonia and water. l'hese can be used singly
or as a mixture of two or more kinds, although water, ethanol or their mixture,
affording the desired product in a high yield, are the preferred solvents.
When the reaction is conducted with the coexistence of ammonia or in a liquid
ammonia solvent, formation of by-products can be prevented, and a similar effect
can be achieved by adding to the solvent for the reaction 0.01 to 5%, preferably,
0.05 to 3.0% of, a basic substance, for example, caustic soda or caustic potash.
As to the amount of the solvent to be used, 0.5 to 10 times the volume of MTN,
preferably 1 to 6 times by volume thereof, is the range in which satisfactory
results can be produced.
In carrying out the hydrogenation, use is generally made of hydrogen
gas, and the reaction vessel is not specifically restricted except that it
should withstand the selected reaction conditions, although it is advisable in
the case of an increased applied reaction pressure, to conduct the reaction
in a pressure vessel such as an autoclave. The reaction pressure is generally
in the region of 5 to 300 kg/cm2G, preferably in the region of 30 to 200 kg/cm2G,
while the reaction temperature is generally in the range of -10 to 250C, prefer-
4S
ably in the range of 50 to 200C.
It is desirable to use a catalyst in the hydrogenation. As examples
of the catalyst, there may be mentioned Raney cobalt, Raney nickel, Raney nickel-
chromium, palladium, platinum, rhodium and ruthenium. These are used singly
or as a mixture of two or more kinds, and, among others, the rhodium catalyst,
providing 116MTA in an increased yield is preferred. When water, ethanol or a
mixture thereof is used as solvent, there results a higher yield of the hydro-
genation reaction, and this may be considered as the most desirable reaction
condition in the case of a one-step production of H6~TA from ~TN.
H6MTA is a colorless clear liquid at ambient temperature and, upon
cooling to 0C, neither solidifies nor produces a precipitate.
The triisocyanate compounds according to the present invention possess
various advantages over conventionally known polyisocyanates. That is to say,
these are completely odorless, non-irritant, by far less viscous, colorless
clear liquids at room temperature, and are of great utility, particularly as a
component for solvent-free or high-solid urethane coatings, while because of the
low cost of starting materials and the simplicity of the production process
employed, they have very high industrial value.
The triisocyanate compounds according to the present invention can
afford various polyurethanes through a variety of polyaddition process utilizing
the reaction between isocyanates and active hydrogen compounds well known in
the industry. The triisocyanates of the present invention, besides being utili-
zable directly in their original form, can be further used as a variety of
modified products known in the industry (such as the dimer, trimer, carbodiimide,
etc.) and also in the form of polymers obtained by reacting them with polyols,
polyamines, aminoalcohols, water, etc. Furthermore, in the case of such applica-
tion fields as baking paints, they can be used in the form of blocked isocyanates
g _
~1~)145
with thc use of a variety of known blocking agents.
As examples of suitable masking agents, there may be mentioned phenols
such as phenol, cresol and isononylphenol, oximes such as butanone oxime and
benzophenone oxime, lactams such as caprolactam, such alcohols as methanol,
esters such as acetoacetate and malonate, triazoles such as benzotriazole,
mercaptan, and others.
Examples of active hydrogen compounds suitable for reaction with the
triisocyanates of the present invention or their corresponding, masked poly-
isocyanates, include compounds containing at leasttwo hydrogen atoms reactable
with the isocyanate and having a molecular weight of 400 to 1000 in general.
Among this kind of compound, particularly suitable are hydroxyl compounds and
compounds having 2 to 8 hydroxyl groups, especially with a molecular weight of
800 to 10000, more preferably 1000 to 6000, are preferred. Employable are, for
example, polyesters, polyethers, polythioethers, yolyacetals, polycarbonates,
polyester amides, or compounds similar thereto, having at least 2 hydroxyl
groups, generally 2 to 8, and preferably 2 to 4. These kinds of compounds are
known per _ as raw materials in polyurethane formation.
As examples of suitable hydroxyl containing polyesters may be men-
tioned reaction products from polyfunctional, preferably divalent, alcohols
(trifunctional alcohol may be added to this~ and polybasic, preferably dibasic,
carboxylic acids. Examples of such acids include succinic acid, adipic acid,
azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid,
phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride,
maleic acid, maleic anhydride, fumaric acid, and the like. Examples of suitable
polyalcohols include ethylene glycol, propylene glycol-(1,2) and -(1,3), buty-
lene glycol-(1,4) a~d -~2,3), hexanediol-(1,6), neopentyl glycol, cyclohexane-
dimethanol (1,4-bis-hydroxymethylcyclohexane), glycerol, trimethylol propane,
- 10 -
114014~
pentaerythritol, diethylene glycol, triethylene glycol, tetraethylene glycol,
pentaethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene
glycol, butylene glycol and polybutylene glycol. In addition to the above-
mentioned polyhydroxy polyesters, polyhydroxy polyethers known in the field of
polyurethane chemistry can also be used for these novel triisocyanates. As
examples of such polyhydroxy polyethers may be mentioned per se known polyethers
having at least 2 hydroxyl groups, generally 2 to 8, preferably 2 or 3. Such
polyethers can be produced by polymerizing in the presence of, for example,
boron trifluoride epoxides themselves such as ethylene oxide, propylene oxide,
butylene oxide, tetrahydrofuran, styrene oxide and epichlorohydrin, or by allow-
ing these epoxides, either as a mixture or successively in turn, to add on to
starting components containing reactive hydrogen atoms. As examples of such
starting compounds containing reactive hydrogen may be mentioned water, alcohols,
amines, etc., such as ethylene glycol, propylene glycol-(1,3) or -(1,2), tri-
methylol propane, 4,4l-dihydroxydiphenylpropane aniline, ammonia, ethanolamine
and ethylene diamine.
Specific examples of these compounds being employable in the present
invention are described, for example, in the following publication: "lligh
Polymers; Vol XVI, Polyurethanes, Chemistry and Technology", edited by Saunders
and Frisch, Interscience Publishers, New York/London, vol. 1, 1962, pages 32
through 42 and pages 44 through 54; vol. 2, 1964, pages 5 through 6 and pages
198 through 199.
Hydroxy-group containing vinylic polymers can also be used as a
reactant for the triisocyanates of the present invention. Such vinylic polymers
are the known reaction products consisting of copolymers from ethylenically
unsaturated monomers containing hydroxyl groups and other kinds of ethylenically
unsaturated compounds such as ethylenically unsaturated esters and hydrocarbons.
- 11 --
~14014S
Examples of such products include copolymers containing the following hydroxyl
monomer components: monohydroxy- and polyhydroxyalkyl maleate and fumarate,
e.g., hydroxyethyl fumarate and compounds similar thereto, acrylates and meth-
acrylates having hydroxyl groups, e.g., trimethylolpropane monomethacrylate,
2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, 2~or 3)-hydroxypropyl
acrylate and methacrylate, 4-hydroxybutyl acrylate and methacrylate, and hydroxy-
vinyl compounds, e.g., hydroxyethyl vinyl ether and allyl alcohol. Furthermore,
partially hydrolyzed products of homopolymers of vinyl acetate, or copolymers
thereof with ethylenically unsaturated compounds can also be used as such polyols.
Acid-group containing polymers obtained by copolymerizing unsaturated
acids such as maleic acid, acrylic acid and methacrylic acid can be used in the
above-mentioned lacquers as well.
The novel triisocyanates according to the present invention or the
masked triisocyanates corresponding to them, in the case where they are utilized
for the above-mentioned two can type polyurethane lacquers, can be mixed not
only with relatively high-molecular weight polyhydroxy compounds as described
above but also any low-molecular weight polyhydroxy compounds having a molecular
weight in the range of 62 to 400. In many instances, it is advantageous to use
a mixture of the above-mentioned relatively high-molecular weight polyhydroxy
compounds and the aforementioned type of low-molecular weight polyhydroxy com-
pounds. The NC0/O}I ratio in such two can type polyurethane lacquers is normally
0.8:1 to 1.2:1.
As examples of suitable low-molecular weight polyhydroxy compo~mds
having the above-mentioned molecular weight range, there may be mentioned diols
and/or triols having hydroxyl groups bonded by the linkage of an aliphatic or
alicyclic type, such as ethylene glycol, propane-1,2-diol propane-1,3-diol,
hexamethylene glycol, trimethylolpropane, glycerol, trihydroxyhexane, 1,2-
- 12 -
114014~
dihydroxycyclohexane, and 1,4-dihydroxycyclohexane. Also sui~able are low-
molecular weight polyols having ether groups, such as diethylene glycol, tri-
ethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol
and tetrapropylene glycol.
In principle, a mixture of the aforementioned polyhydroxy compounds may
be utilized, provided, however, that thc components in the mixture are compatible
with one another.
A lacquer produced in accordance with the present invention and using
the novel triisocyanates or the masked triisocyanates corresponding to them
offers the following great advantages: that is to say, such lacquer can be
used in the absence of a solvent, and therefore produce weathering-resistant
coating films with excellent mechanical properties without evolution of air
bubbles.
During the production of such lacquer compositions addition of a mois-
ture absorbing agent or dehydrating agent is not necessary.
The lacquer of the present invention can be mixed with pigments and
fillers in an apparatus ordinarily employed by the lacquer industry.
Needless to say, other raw materials and/or auxiliary materials for a
lacquer, such as cellulose ester, levelling agent, plasticizer, silicon oil,
resins and/or other materials conventionally employed, can be added.
In order to control the reactivity of such polyurethane lacquer, known
catalysts may be used. The lacquer can be applied for covering on the surface
of a substrate by conventional procedures, for example, by brushing, spraying
or dipping. The lacquer is especially valuable for covering arbitrary articles
produced from wood, metal, plastics, or other materials. The triisocyana~e
compounds according to the present invention can be utilized as raw materials for
polyurethane adhesives, foams, artificial leather and filling agents, in addition
- 13 -
1140145
to urethane coatings.
Reference Example l
In an autoclave of 300-ml content fitted with an electromagnetic
agitator were placed for tight sealing 15 g of 1,3,5-tricyanobenzene (MTN), 15 g
of Raney nickel-chromium catalyst prepared according to the conventional method
(atomic ratio of Ni:Cr=49:1), 27 ml of methanol, 63 ml of m-xylene and 0.18 g
of caustic soda, and hydrogen was charged at the initial pressure of 100 kg/cm2G
to conduct the reaction at 100C, resulting in absorption of 0.59 mole of hydro-
gen over a 35 minute period. The catalyst was filtered out and the solvent was
distilled off, followed by conducting vacuum distillation, thus resulting in
12.8 g of 1,3,5-tris(aminomethyl)-benzene CMTA).
The MTA was in the form of colorless crystals at ambient temperature,
having a melting point of 49 to 51C and a boiling point of 136 to 139C/0.4
mmHg, and, upon heating at about 50C, turned into a colorless, clear liquid.
Reference Example 2
In an autoclave of 300-ml content fitted with an electromagnetic
agitator was placed for tight sealing 30 g of 1,3,5-tris(aminomethyl)-benzene
(MTA), together with 3 g of 5% ruthenium-alumina catalyst (produced by Japan
Engelhardt Co.), 60 g of water and 0.75 g of caustic soda, and high-pressure
hydrogen was charged at 120 kg/cm G initial pressure to react at 115C for 25
minutes, resulting in absorption of 0.61 mole of hydrogen.
The catalyst was filtered out, and the solvent was distilled off,
followed by vacuum distillation, resulting in 26.8 g of 1,3,5-tris(aminomethyl)-
cyclohexane (H6MTA). The H6MTA was a colorless, clear, less viscous liquid
having a boiling point of 127 to 128C/l mmHg.
Reference Example 3
In an autoclave of 300-ml content fitted with an electromagnetic
- 14 _
1~4014~
agitator was placed for tight sealing 20 g of 1,3,5-tricyanobenzene (MTN) to-
gether with 80 ml of 25% aqueous ammonia, 300 mg of caustic soda and 4 g of a
commercially available 5% rhodium-alumina catalyst, and the mixture was subjected
to reaction under high-pressure hydrogen of 120 kg/cm2G initial pressure at
105C for 70 minutes, resulting in absorption of 0.95 mole of hydrogen. By the
above procedure was obtained, in a yield of 45%, H6MTA having both the nitrile
and benzene ring reduced.
The accompanying Figures l and 2 show IR spectra of products described
in Examples 1 and 2.
Example l
In 1200 ml of o-dichlorobenzene in a 2 liter four-necked flask was
dissolved with warming 90.0 g of 1,3,5-tris(aminomethy~-benzene ~MTA). Carbon
dioxide gas was introduced into the resultant amine solution until no weight
increase was observed, resulting in a slurry of colorless crystals. The slurry-
formed material was maintained at a temperature of not higher than 10C for 30
minutes, while blowing in phosgene gas under stirring, and the temperature was
elevated to 130C over a 2 hour period while feeding in phosgene, followed by a
maintained temperature of 13QC for 5 hours. As the phosgenation reaction pro-
ceeds, the slurry turned to a solution and, eventually, to a uniform, slightly
yellowish, clear solution.
After the completion of the phosgenation reaction phosgene was releas-
ed from the solution by blowing nitrogen gas, and the o-dichlorobenzene solvent
was di.stilled off under reduced pressure. Vacuum distillation of the resultant
crude isocyanate afforded 112.9 g of 1,3,5-tris(isocyanatomethyl)-benzene (MTI)
having a boiling point of 173 to 175C/0.4 mmHg (a molar yield of 85.2%). The
MTI was a less viscous liquid even at 5C and completely free from odor peculiar
to isocyanates. I`t was found to have an amine equivalent of 83.25 ~the theoreti-
- 15 -
145
cal value was 81.1). IR spectra of ~TI thus obtained is shown in Figure 1.
The resultant MTI contained trace amounts of impurities, and in order
to make definite identification thereof, the following experiment was carried
out: a small amount of the MTI was reacted with a large quantity of methanol
to obtain its methylurethane derivative, and recrystallization of the same from
acetone as the solvent afforded the trimethylurethane derivative of MTI as white
crystals (recrystallization yield of 71.5%). Results of elementary analysis
on the purified trimethylurethane compound was found to be in good agreement
with the theoretical value. Melting point; 155-156C.
Elementary analysis (for C15H21N306):
Calcd. (%) Found (%)
C53.09 53.03
H 6.24 6.01
N12.38 12.09
Example 2
Phosgenation was carried out in the same manner as in Example 1, ex-
cept that 70.0 g of 1,3,5-tris(aminomethyl~-cyclohexane (H6MTA) was used in
place of 1,3,5-tris(aminomethyl)-benzene ~lTA) and that tlle reaction temperature
was elevated from 10C to 120C over a 6-hour period, followed by maintaining
a temperature of 120C for 6 hours. By the above procedure, there was obtained
91.8 g of 1,3,5-tris(isocyanatomethyl~-cyclohexane (H6MTI) having a boiling
point of 170 to 174C/0.53 mmHg (molar yield of 90.1%). The H6MTI was a liquid
less viscous even at 5C and free from odor. The amine equivalent was found to
be 84.71 (calculated was 83.08). lR spectra of H6MTI thus obtained is shown in
Figure 2.
A trimethylurethane derivative of H6MTI, purified through methylurethane
formation and recrystallization from acetone as was the case with MTI, had the
- 16 -
~1~0~4~
following values of elementary analysis:
Elementary analysis (for C15H27N306);
Calcd. (%) Found (%)
C 52.16 52.27
H 7.88 8.00
N 12.17 11.88
Example 3
Into a one liter, four-necked flask was charged 250 g of o-dichloro-
benzene, which was then allowed to absorb phosgene under ice-cooling. While
phosgene was blown into it, a solution of 45.2 g of 1,3,5-tris(aminomethyl~-
benzene (MTA) in 500 g of o-dichlorobenzene was added dropwise over a 100-minute
period. As the addition proceeded, the liquid contained in the flask showed a
rising viscosity and turned into slurry form. After the addition of the amine
was completed, the reaction mixture was maintained at not higher than 10C for
30 minutes and then heated up to 130C over a 5-hour period, while phosgene was
blown, followed by reaction at 130C for 6 hours to thus complete the phosgena-
tion.
By the same procedure as in Example 1, there was obtained 54.8 g
(yield of 82.4%) of MTI~
In the same manner as in Example 3, 42.3 g of 1,3,5-tris(aminomethyl)-
cyclohexane (H6MTA) was phosgenated to give 53.0 g ~yield of 86.1%) of H6MTI.
Example 5
Using the MTI obtained in Example 1, a highly nonvolatile two-can
type urethane coating was prepared with the rollowing components:
Component A:
1) Acrylic polyol [a copolymer solution with 65% nonvolatile content
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1~0145
and 0~l value of 65 produced by copolymerizing in a toluene/butyl acetate mixedsolvent (1:1) 50% of styrene, 23.2% of 2-hydroxyethyl methacrylate and 26.8%
of n-butyl acrylate] 863 parts
2) Titanium dioxide powder 429.5 parts
3) Ethyl acetate/butyl acetate/cellosolve
acetate (1/1/1) 276.1 parts
Component B:
MTI 83.3 parts
Component A with the pigment well dispersed by means of a ball mill
was mixed with component B in such a proportion as realizes a ratio of
NCO/OH=l/l. The mixture showed 65% nonvolatile content and 24 seconds of vis-
cosity, as determined with the use of ~ord cup #4 at 25C. It was immediately
spray-applied on a soft steel plate surface-treated with phosphoric acid to 30
to 40/u of thickness of a dried coating film. After conducting conditioning at
25C for 7 days, determination of physical properties and weathering test were
effected with the coating film.
Coating film thickness: 30 to 40~u
Pencil hardness H
Erichsen extrusion test 8.5 mm
Cross cut test 100/100
Sunshine type l~eather-O-Meter 500 hr ~E 1.2
Examples 6-8
Using MTI as obtained in Example 1 or H6MTI as obtained in Example 2
in combination with a variety of polyols, two-can type urethane coatings with a
high nonvolatile content were prepared in the same manner as stated in Example
5 to investigate physical properties and weatherabilities of resultant coating
films. The results obtained are tabulated in Table 1.
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-- 1140145
Table 1
Experiment No. 6 7 8
_
Component A:
Polyol (parts) Polyester Acrylic Polyester
polyol (I) Polyol Polyol (II)
255 863 243.9
Titanium dioxide 225.5 430.4 219.1
(parts)
Solvent (parts)BA 241.6 EA/BA/CA BA 136.9
(1/1/1)277.4
Component B: (parts)~TI 83.3H6MTI 84.7 H6MTT 84.7
At the time of mixing
of Comnonents, A and B:
Nonvolatile conent
(%) 70 65 80
Viscosity (sec.) 24 26 27
Physical ro erties:
P P
Thickness of coating
fîlm ~) 30 to 40 30 to 40 30 to 40
Pencil hardness HB 11 IIB
Erichsen (mm) 8.5 8.2 8.0
Cross cut test 10Q/100 100/lO0 100/100
Weatherability, ~E 1.6 Q.3 0.7
Remarks:
Polyester polyol (I); A condensate, with lQ0% of nonvolatile content and an OH
value of 22, formed from 2 moles of adipic acid, 1 mole of dipropylene glycol,
2 moles of trimethylol propane and 1 mole of coconut-oi1 based fatty acid.
Acrylic polyol; A copolymer solution with 65% of nonvolatile content and OH
value of 65, produced by copolymerizing 50% of styrene, 23.2% of 2-hydroxyethyl
methacrylate and 26.8% of n-butyl acrylate in toluene-butyl acetate (1:1).
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11~0~4S
Polyester polyll II; A condensateJ with 100% of nonvolatile content and OH
value of 230) formed from 2 moles of adipic acid 1 mole of diet~ylene glycol,
2 moles of trimethylol propane and 1 mole of coconut-oil ~ased fatty aci.d.
BA: Butyl acetate
EA: Ethyl acetate
CA: Cellosolve acetate.
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