Polyurethane resins and polyurethane resin coating compositions

Polyurethane resins with an excellent weather resistance are provided by the reaction of polyols with trifunctional isocyanates which are expressed by the following general formula: ##STR1## (R=a remnant of divalent hydrocarbon group with carbon number of 2 or 3) The reaction between a polyol and a trifunctional isocyanate is effectuated at an NCO/OH mole percentage of 0.5 to 2.0, and adjustments are made so that the concentration of carbamide group will be 5.times.10.sup.-4 to 50.times.10.sup.-4 moles per gram of the reaction product, and that the bridging parameter will be 150 to 1,500. The resins may be used to best advantage as polyurethane resin coatings excelling in weather resistance.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to polyurethane resins which are beneficial 
as material producing a polyurethane resin coat with, in particular, an 
excellent weather resistance. 
2. Description of the Prior Art 
Polyurethane resins are classified into two types by the kind of isocyanate 
compounds contained in them--the "yellowing" and "non-yellowing" types. 
Isocyanates which have hitherto been in use as ones giving polyurethane 
resins of the non-yellowing type include: such aliphatic isocyanates as 
hexamethylenediisocyanate, isophoronediisocyanate, 
2,2,4-trimethylhexamethylenediisocyanate, dicyclohexylmethanediisocyanate, 
etc.; and xylilenediisocyanate, etc. Whilst non-yellowing type 
polyurethane resins obtained by causing these isocyanates to react with 
polyols have been employed as coating materials, there still remained many 
problems to be solved in using them for such purpose. 
One of the problems is their toxicity. Since isocyanate compounds are 
substances which are chemically highly reactive, they are very dangerous 
when used by persons who are of an allergic constitution or have weak 
respiratory organs. Because of this, the limit of concentration in the 
atmosphere of, for instance, monomers of toluenediisocyanate, 
diphenylmethanediisocyanate, etc., was fixed at 0.02 ppm by the Commission 
of the American Conference of Governmental Industrial Hygienists. For such 
reason, for one thing, the aforesaid isocyanate monomers are seldom used 
as they are in polyurethane coatings, except in special cases, but are 
generally used after having been modified into prepolymers--adducts 
obtained by adding them to trimethylolpropane, ethylene glycol, etc. This 
modification has the effect of lowering vapor pressure, thereby reducing 
toxicity and bad odor, and, in addition, of allowing the adjustment of 
reactivity to be made and the diversification of the type of coatings to 
be realized. 
Since, however, it is industrially extremely difficult to wholly eliminate 
isocyanate monomers in the prepolymer additions, the fact is still that 
one smells a strong irritating odor while he is engaged in the work of 
preparing coating materials or of applying coats, many people complaining 
of the symptoms of respiratory diseases peculiarly contracted by inhaling 
isocyanate vapor, and with an increase in the use of polyurethane 
products, this question has been brought much to the fore. 
With the isocyanate additions, in particular, it is said that there occurs 
dissociation of diisocyanates--highly toxic monomers--while they are in 
store, depending upon the storage conditions, and this constitutes an 
uneasy factor for those concerned--chemical engineers and operators. Under 
such circumstances, measures are being taken for improvement of the 
working environment, for instance, ensuring a good ventilation, so that 
the operators will not directly inhale vapor of isocyanate compounds. 
However, the state of things in this connection is still far from being 
satisfactory. 
The second question in the conventional technology is that there remains, 
with the conventional coatings, much to be desired in respect of their 
weather resistance. Although the non-yellowing type polyurethane resins 
were originally developed with a view to improving the weather resistance 
of coatings, they are not, as yet, sufficiently resistant to weather when 
used as coating for application to those commodities which are exposed to 
severe conditions outdoors over a long period of time, such as 
automobiles, railroad carriages, aircrafts, vessels, building materials, 
and so forth. 
The third question concerning polyurethane coating materials according to 
the conventional techniques is that the range in which the selection of 
solvent composition can be made is not necessarily wide enough, and that, 
if the amount of solvent is reduced from the viewpoint of energy saving 
and prevention of environmental pollution, the resultant product being the 
so-called "high solid type" coating with a high concentration of 
polyurethane resin, the coating work efficiency is much impaired because 
of its high viscosity. 
SUMMARY OF THE INVENTION 
The main object of the present invention is to provide polyurethane resins 
and polyurethane resin coatings having a high resistance to weather. 
Another object of this invention is to provide polyurethane resin coating 
compounds affording an improved coating work efficiency. 
Still other objects of the present invention will become clear from the 
description to follow. 
A polyurethane resin film coat with an excellent weather resistance is 
provided by the present invention. This film coat has for its main 
ingredient a polyurethane resin which is a reaction product obtained by 
causing 
(A) a polyol 
to react with 
(B) a trifunctional isocyanate 
expressed by the following general formula: 
##STR2## 
(R=a remnant of divalent hydrocarbon group with the carbon number of 2 or 
3) 
at an NCO/OH mole percentage of 0.5 to 2.0, and of which the concentration 
of carbamide group is 5.times.10.sup.-4 to 50.times.10.sup.-4 moles per 
gram of said reaction product, and the bridging parameter 150 to 1,500. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A polyol as referred to in the present invention means a compound or 
polymer containing two or more hydroxyl groups per molecule. 
As examples of polyols, there are diols, triols, tetraols, pentols and 
hexitols; while there are also such polymer polyols as polyester 
containing two or more hydroxyl radicals per molecule (hereinafter called 
"polyester polyol"), polyether containing two or more hydroxyl groups per 
molecule (hereinafter called "polyether polyol"), acrylic polymer 
containing two or more hydroxyl radicals per molecule (hereinafter called 
"polyacryl polyol"), etc. In the present invention, these may be used 
either singly or as a mixture of two or more kinds. Hereunder are given 
further examples, in more particulars, of polyols. 
Diols: 
ethylene glycol, propylene glycol, .beta..multidot..beta.'-dihydroxydiethyl 
ether (diethylene glycol), dipropylene glycol, 1,4-butylene glycol, 
1,3-butylene glycol, polyethylene glycol, polypropylene glycol, 
polpropylene-polyethylene glycol, polybutylene glycol; 
Triols: 
glycerine, trimethylol propane, 1,2,6-hexanetriol; 
Tetraols: 
penta erythritol, 2-methylglucoside; 
Hexitol: 
sorbitol; 
Polyester polyols: 
These are polymerized by the condensation reaction between a polybasic 
acid, such as adipic acid, dimer acid, phthalic anhydride, isophthalic 
acid, etc., and a diol or triol, such as ethylene glycol, diethylene 
glycol, propylene glycol, trimethylol propane, glycerine, etc. 
Polyether polyols: 
These are prepared by adding propylene oxide, ethylene oxide, or the like, 
to a polyhydric alcohol, such as glycerine, propylene glycol, etc. In this 
category are also included polyether polyols rich in hydroxyl radicals 
obtained by causing a multifunctional compound such as ethylenediamine, 
ethanolamine, etc. to react with ethylene oxide or propylene oxide. 
Polyacryl polyols: 
Copolymers of an acrylic acid ester or methacrylic acid ester containing a 
hydroxyl group expressed by the following general formula: 
##STR3## 
wherein n=1, 2 and 3 
R.sub.1 =hydrogen or methyl 
R.sub.2 =a remnant radical of substituent or nonsubstituent hydrocarbon 
with the carbon number of 2 to 12 
and a monomer which is capable of being copolymerized with such. 
Hereunder are enumerated examples of acrylic acid esters or methacrylic 
acid esters containing the aforesaid hydroxyl group. 
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 
2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl 
methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxypentyl methacrylate, 
methacrylic acid monoester of glycerine, acrylic acid or methacrylic acid 
monoester of trimethylol propane, 2-hydroxy-3-chloropropyl acrylate, 
2-hydroxy-3-chloropropyl methacrylate, etc. 
Out of these, the most desirable are: 2-hydroxylethyl methacrylate, 
2-hydroxyethyl acrylate and 2-hydroxypropyl methacrylate. In the next 
place, examples of monomers which are capable of being copolymerized with 
the abovementioned acrylic acid or methacrylic esters containing a 
hydroxyl group are given below. 
(1) acrylic acid or its esters, for example, acrylates of methyl, ethyl, 
propyl, butyl or 2-ethylhexyl 
(2) methacrylic acid or its esters, for example, methacrylates of methyl, 
ethyl, butyl, decyl, 2-ethylhexyl or lauryl 
(3) styrene or its derivatives, for example, .alpha.-methylstyrene, 
.beta.-chlorostyrene, etc. 
(4) vinyl esters, for example, vinyl acetate, vinyl propionate, vinyl 
isopropionate, etc. 
(5) nitriles, for example, acrylonitrile, methacrylonitrile, etc. 
Out of these, the most desirable are: methyl acrulate, ethyl acrylate, 
butyl acrylate, methyl methacrylate, butyl methacrylate, lauryl 
methacrylate, acrylic acid, methacrylic acid, styrene, acrylamide, vinyl 
acetate, etc. 
To prepare polyacryl polyols best suited for the purpose, it is desirable 
that the amount of each monomer used be selected from the following 
ranges: 
(A) Hydroxyalkyl(meth)acrylate . . . 5 to 30 pct. by wt. 
(B) Alkyl ester of acrylic acid and/or of methacrylic acid . . . 50 to 95 
pct. by wt. 
(C) Other monomer(s), as occasion demands . . . 0 to 50 pct. by wt. 
(D) Acrylic acid or methacrylic acid . . . 0 to 10 pct. by wt. 
If, of the foregoing, the amount of hydroxyalkyl(meth)acrylate is less than 
5 pct. by wt., the degree of bridging by reaction with isocyanate 
compounds becomes too small and hence it will be impossible to obtain a 
film coat with such performance as was expected. 
While the manufacture of polyacryl polyols by copolymerization of monomers, 
as described above, may be carried out by any one of such known methods of 
polymerization as solution, block, emulsion and suspension polymerization, 
the first mentioned method, i.e., solution polymerization is generally 
employed. 
Selection of polyols may be made at one's discretion so as to fit the 
purpose, but, in general, the use of polyester polyols or polyacryl 
polyols is preferable. 
As for the molecular weight of polyols used, too, selection may be made 
from quite a wide range according to the purpose. For the "high solid 
type" coating, however, a range of 500 to 5,000, especially, 500 to 3,000, 
is preferred. More particularly, when polyester polyols are used, those 
with a molecular weight in the range of 500 to 1,000 are best suited for 
the purpose; while when polyacryl polyols are used, those with a molecular 
weight in the range of 1,000 to 3,000 may be utilized to best advantage. 
When manufacturing coatings which are not of the "high solid type", 
polyols with a molecular weight higher than ordinary are employed. 
The trifunctional isocyanate compounds employed in the present invention 
are those expressed by the general formula previously given in this 
specification, of which typical examples include: 
2,6-diisocyanate caproic acid -.beta.-isocyanate ethyl ester; 2, 
6-diisocyanate caproic acid -.gamma.-isocyanate propyl ester; 
2,6-diisocyanate caproic acid -2-methyl-.beta.-isocyanate ethyl ester; 
etc. 
All these can be manufactured by causing an ester of lysine and 
aminoalcohols to react with phosgene. 
Here, it is difficult to achieve polymerization if, in the aforesaid 
general formula, the carbon number of R is 1; while if the carbon number 
is 4 and over, the content of isocyanate in the trifunctional isocyanates 
becomes too small, and this will be detrimental to the physical properties 
of polyurethane resin film obtained by the reaction with polyols, and 
will, besides, make the viscosity of the trifunctional isocyanate 
compounds higher, thus making the product unsuitable for the purpose of 
this invention. 
By making a proper choice of polyols to be used and by adjusting the NCO/OH 
mole percentage, the physical properties and hence efficiency of the 
product, such as the strength of film coat, flexibility, chemical 
resistance, solvent resistance, etc., can be modified in a wide range, 
thereby to make it suitable for specific purposes. 
Compounds of which the NCO/OH mole percentage is in the range of 0.5 to 2.0 
are suited for the manufacture of films and for the application of film 
coat. For polyurethane coatings, in particular, the range of 0.5 to 1.2 is 
preferred. 
If the NCO/OH mole percentage is below the lowest figure, as above, hot 
water and acid resistance of the film coat produced is lowered, resulting 
in a poorer weather resistance. When it is above the highest figure, too, 
there takes place a lowering of weather resistance. 
Those with an NCO/OH mole percentage in the range of 0.5 to 1.0 may be used 
to advantage for such fields as electrical insulation, capsulation, and 
manufacture of cast products. 
When the NCO/OH mole percentage is in the range of 0.1 to 0.7, such 
compounds may be advantageously utilized for the manufacture of highly 
efficient adhesives or hardening agents. When, on the other hand, the 
NCO/OH mole percentage is greater, such compounds are suited for the 
manufacture of foam products. The foaming may be achieved by introducing a 
certain fixed amount of water or a blowing agent into the reaction 
products, by utilization of the known techniques of foaming. 
It is necessary that the concentration of the carbamide contained in the 
product of reaction between a polyol and a trifunctional isocyanate be in 
the range of 5.times.10.sup.-4 to 50.times.10.sup.-4 moles per gram of 
said reaction product. The term "carbamide radical" as herein used 
indicates a group expressed by this: 
##STR4## 
which exists in the urea bond, urethane bond, biuret bond and allophanate 
bond. In an IR analysis, the existence of this carbamide radical can be 
confirmed from a peak somewhere around 1530 cm.sup.-1. If the 
concentration of the carbamide radical is lower than the above, it is 
impossible to obtain a film coat which excels in durability, pliability, 
solvent and chemical resistance, adhesive power, etc. If, on the other 
hand, the concentration is higher than the above, a film coat produced 
will have a poorer weather resistance. 
It is necessary that the bridging parameter E (calculated value) of the 
aforesaid reaction products be in the range of 150 to 1,500. If it is 
lower than this lower limit, the pliability of a film coat obtained will 
be very poor. If, on the other hand, it is higher than the upper limit, a 
film coat with a good durability cannot be obtained, here, the bridging 
parameter E.sub.c indicates a parameter so defined by T. C. Patton (Off. 
Digest, 34-446, 348 '62), as hereunder given, viz.: 
##EQU1## 
wherein W.sub.1 =weight of polyol; 
W.sub.2 =weight of isocyanate; 
F.sub.1 =degree of functioning of polyol; 
F.sub.2 =degree of functioning of isocyanate; 
C.sub.1 =degree of bridging function of polyol, C.sub.1 =F.sub.1 -2; 
C.sub.2 =degree of bridging function of isocyanate, C.sub.2 =F.sub.2 -2; 
E.sub.1 =equivalent weight of polyol; and 
E.sub.2 =equivalent weight of isocyanate. 
The polyurethane resin coating of the present invention is adaptable to 
both the one-component and two-component types, but it is more 
advantageous to use it as the two-component type coating. 
(1) Two-Component, Polyol Hardening Type 
This is a two-component type polyurethane resin coating constituted of a 
kneaded mixture of a polyol and a pigment, the latter being added at need 
("A" liquid) and a trifunctional isocyanate of the present invention, 
diluted with a solvent as needs be ("B" liquid). At use, "A" and "B" 
liquids are mixed together and, when necessary, the viscosity is adjusted 
by the use of a thinner. For mixing the two liquids, a two-liquid gun may 
preferably be employed. It is desirable that the mixing ratio be 
determined in such a manner that the NCO/OH mole percent will be 0.5 to 
2.0, concentration of carbamide radical 5.times.10.sup.-4 to 
50.times.10.sup.-4 moles per gram of the reaction product, and briding 
parameter 150 to 1,500. 
The solvent of "B" liquid and the thinner of the mixture, which are used at 
need, may be either the same or different; but, in the latter case, it is 
necessary that the two are compatible with each other. Further, these must 
not be ones which are reactive with isocyantes and polyols, such as ones 
containing active hydrogen atoms. Some examples of solvents that may be 
used are given below. 
Hydrocarbon solvents: 
benzene, toluene, xylene, and aromatic naphtha. 
Ester solvents: 
ethyl acetate, butyl acetate, cellosolve, hexyl acetate, amyl acetate, 
ethyl proprionate, and butyl proprionate. 
Ketone solvents: 
acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl 
ketone, diethyl ketone, and cyclohexanone. 
Glycol ester solvents: 
ethylene glycol monoethyl ether acetate, and diethylene glycol monoethyl 
ether acetate. 
One of the characteristics of the present invention lies in that, of the 
whole composition of solvent, more than 50 pct. by wt. can be the 
aforesaid hydrocarbon solvent. 
Further, the amount of solvent in the aforesaid "B" liquid can be as small 
as 0 to 50 pct. by wt., and this also constitutes a characteristic of the 
coating in accordance with the present invention. This makes it easier to 
obtain a "high solid type" coating--a contributing factor to an 
improvement of the outward appearance of film coats. 
As for polyols to be used, those which were previously mentioned, that is, 
polyester polyols, polyether polyols, polyacryl polyols, etc., are 
recommended. These are certain to give good results. 
By combining proper kinds of polyols and isocyanate compounds, it is 
possible to obtain coats of varied properties, from soft to hard and tough 
ones, all of which being possessed of an excellent resistance to weather, 
water, chemicals and stain. Coatings of this type are ordinarily used at 
temperatures ranging from room temperature to 120.degree. C. They display 
an excellent adhesive property when used for coating of such materials as 
ferrous and nonferrous metals, plastics, rubber, leather, concrete, etc., 
and hence have a wide range of applications in such fields of industries 
as manufacture of building materials, automobiles, machines and 
instruments, and woodworks; building of aircrafts, railroad carriages and 
ships; and so forth. 
(2) One-Component, Heat Curing Type 
With coatings of the two-component, polyol hardening type which has been 
described in the foregoing, the reaction progresses even at room 
temperature; hence there frequently arise cases where the pot life of 
coatings in use presents a problem. 
In this type of coating, one-liquid, heat curing type, the isocyanate group 
of isocyanate compounds is once blocked by the addition of a blocking 
agent so that the coating will be stable at room temperature. The coating, 
after having been applied, is heated to dissociate the blocking agent. The 
isocyanate group is thus activated again and is caused to react with the 
hydroxyl group to form a film coat. This method is best suited for such 
applications as coating of automobiles on a manufacturing line, or the 
like, where it is necessary to ensure stability of coating materials while 
they are in store at room temperature. 
As polyols to be combined with the blocked type isocyanate prepolymer, 
polyester polyols and polyacryl polyols may be used to best advantage. 
As blocking agents for the purpose of masking free isocyanate radical of 
the trifunctional isocyanate compounds used in the present invention, 
those which are in general use may be brought into employment. Hereunder 
are given some examples of such blocking agents: 
Phenol, m-nitrophenol, p-chlorophenol, catechol, ethyl malonate, 
acetylacetone, ethyl acetoacetate, cresol, .epsilon.-caprolactam, methyl 
ethyl ketoxime, cyclohexanoneoxime, butyl mercaptan, methanol, ethanol, 
ethylene, chlorohydrin, etc. 
Although the temperature at which the above-mentioned blocking agents are 
dissociated varies with the kind of such agents, it is generally accepted 
that heating to at least 120.degree. C. is required. Since the coating of 
this type thus requires baking at a relatively high temperature, it has 
hitherto been in use mainly in such fields as the manufacture of electric 
wires, etc. It is expected, however, that there will be new developments 
in its utilization, such as adaptation to a powder paint with polyurethane 
resin base, to an aqueous emulsion paint, and so forth. 
Solvents for this type of coating, which are used as occasion demands, are 
identical with those in the case of the two-component type coatings. In 
this instance, too, more than 50 pct. by wt. of the whole composition of 
solvents can be hydrocarbon solvents. 
The coating compounds according to the present invention can be applied to 
articles to be coated in an ordinary method of coating, such as spray, 
brush or roller coating, or dipping. It also permits the use of commonly 
used pigments and plasticizer, or other kind of additives which are used 
in small amounts when preparing the paint or when applying it, provided 
that the amount used is within the limit of the common practice. For the 
choice of pigments, it is necessary to pay attention to their water 
content, as well as to their properties like in the case of selecting 
solvents. It is to be noted that extenders, in particular, have a great 
water adsorbability. 
Catalysts may also be used to quicken drying and hardening. For instance, 
such tertiary amines as dimethylethanolamine, triethylenediamine, etc., 
and such organic salts of tin as stannous, dibutyl tin dilaurate, etc., 
may be employed. 
The characteristics of the coating according to this invention are as 
follows: 
(1) It excels in gloss retention and anti-cracking properties. 
(2) It has an excellent resistance to acid and water. It is thought that, 
besides this comes from the fact that it hardens very quickly after 
application, such property is closely related to the network-like 
structure of the coat produced by hardening with the trifunctional 
isocyanate compound used in the present invention. 
(3) It facilitates an improvement in the outward appearance of the coat. 
Whilst the luster and build of a coat are related to various factors, the 
influence of the coating on the under coat is a factor which must not be 
left unheeded. With the compounds of this invention, it is possible to use 
a variety of solvents and, in particular, much of aromatic compound 
solvents. This permits lessening the influence of the coating on the under 
coat, for instance, primer surfacer; that is the permeation of the solvent 
is kept to the minimum, helping to achieve an improvement in the outward 
appearance of the coat. Thus, it is best suited for such purposes as 
coating of automobiles, etc., where an emphasis is placed on a good 
outward appearance. 
(4) It contributes to development of coatings of the "high solid type". 
Amidst the recent moves for restriction on environmental pollution, the 
development of polyurethane resin coatings of the "high solid type" or of 
the solventless type is attracting much attention of the circles 
concerned. Isocyanate as an ingredient of such coatings is required to 
have, like the polyol ingredient, a low viscosity at room temperaure. As 
the trifunctional isocyanate used in the present invention has a low 
molecular weight, it has a low viscosity, hence may be intended for the 
manufacture of coatings that will help to prevent environmental pollution. 
It is also possible, by proper choice of polyols, to manufacture 
solventless coatings and thus to contribute to savings in resources or 
energy. 
The coating of the present invention is, because of its low viscosity, 
excellent in respect of coating work efficiency, too. 
(5) Hardening speed is great. 
Although the hardening speed at room temperature is not so clearly 
different from that of coating materials on the market, it becomes 
considerably greater than the latter with the rise of baking temperature. 
Thus, it is possible to shorten the time required for curing. 
(6) Low toxicity. 
Hexamethylenediisocyanate prepolymers or adducts have, in general, a pretty 
strong irritating odor. This is because, it is said, of the existence of a 
very small amount of hexamethylenediisocyanate monomers in the prepolymers 
or adducts. With, on the other hand, the trifunctional isocyanate 
compounds employed in the present invention, the vapor pressure is 
remarkably low, and there is, while they are being kept in store, no 
liberation of volatile ingredients with high toxicity. Also, their NCO 
content is higher than that of coating materials on the market. Therefore, 
the coating of this invention emits little irritating odor which is 
peculiar to the isocyanate content of coatings. As, besides, the 
proportion of the isocyanate ingredient to that of the polyol ingredient 
may, in view of its high NCO content, be reduced, it is quite advantageous 
from the viewpoint of hygene. 
The polyurethane resin of the present invention may be put to, besides in 
use as coating material as above, a wide range of uses in various fields 
of industries. 
For instance, those with an NCO/OH mole percentage in the range of 0.5 to 
1.0 may be used to advantage for such fields as electrical insulation, 
capsulation, and manufacture of cast products. 
When the NCO/OH mole percentage is in the range of 0.1 to 0.7, such 
compounds may be advantageously utilized for the manufacture of highly 
efficient adhesives or hardening agents. When, on the other hand, the 
NCO/OH mole percentage is greater, such compounds are suited for the 
manufacture of foam products. The foaming may be achieved by introducing a 
certain fixed amount of water or a blowing agent into the reaction 
products, by utilization of the known techniques of foaming. 
In the following, the present invention will be explained in concrete terms 
by citing several examples of its embodiment and comparing them with a few 
examples of cases where the method of preparation is not quite the same. 
"Part or parts", of the compositions shown in the examples, means "part or 
parts by weight". 
&lt;Polymerization of 2, 6-diisocyanate caproic acid -.beta.-isocyanate ethyl 
ester as a trifunctional isocyanate compound&gt; 
122.2 g (2.0 moles) of ethanolamine, 100 ml of o-dichlorobenzene and 420 ml 
of toluene were put in a four-mouthed flask fitted with a stirrer, a 
thermometer, a gas-introducing tube and a reflux condenser combined with a 
Dean-Stark apparatus; and by introducing into it hydrogen chloride gas 
under ice cooling, ethanolamine was converted into hydrochloride. 
Subsequently, 182.5 g (1.0 mole) of lysine-monohydrochloride was added; by 
heating the mixture to a reaction temperature of 80.degree. C., 
hydrochloride of ethanolamine was caused to melt; and then by introducing 
into it hydrogen chloride gas, it was converted into 
lysine-dihydrochloride. It was continued to pass hydrogen chloride gas 
through the compound at a rate of 20 to 30 ml per min., with the reacting 
mixture heated to the reflux temperature (116.degree. C.), and such 
temperature was maintained until there no longer was distillation of 
water. The reaction was let to continue for approximately 8 hours; 
thereafter, the solvent was decanted, and to the resultant oil-like 
substance was added a mixture of methanol and ethanol and a heat was 
applied. When such product was let to stand at room temperature, there was 
a deposition of crystals. By filtering out these crystals, 165 g of 
tertiary hydrochloride of lysine-.beta.-aminoethyl ester having a melting 
point of 175.degree. C., recrystallized from the mixture of methanol and 
ethanol, was obtained. 
This trihydrochloride was pulverized and was then vacuum-desiccated at 
50.degree. C. for 8 hours. Subsequently, it was put in a four-mouthed 
flask provided with a stirrer, a thermometer, a gas-introducing tube and a 
reflux condenser, and by pouring 2.1 lit. of o-dichlorobenzene into it, it 
was made into a suspension. While stirring this suspension, phosgen was 
passed through it at a rate of 2.8 moles/hr., and the suspension was 
heated at 120.degree. C. for 10 hours. When the temperature was gradually 
raised to 150.degree. C. over a space of time of 6 hours, the suspensoid 
was practically wholly dissolved into the liquid. After cooling, the 
liquid was filtered and the solvent was eliminated by distillation under 
reduced pressure. The residue was distilled under nitrogen gas flow using 
an oil diffusion pump. The product: 140 g (yield 90%) of lysine isocyanate 
.beta.-isocyanate ethyl ester (2, 6-diisocyanate caproic acid 
-.beta.-isocyanate ethyl ester) (hereinafter to be called "LTI-E" for 
short) with a boiling point of 155 to 157.degree. C./0.022 mmHg, a 
colorless, transparent liquid. Viscosity: 29 cps/20.degree. C. NCO 
content: 47.1% by wt. (calculated value 47.2% by wt.). 
Infrared spectrum: 2225 (isocyanate group), 1745 cm.sup.-1 (ester 
carbonyl), 1460, 1355, 1200 cm.sup.-1 (ester ether). 
Nuclear magnetic resonance spectrum: 1.2 to 2.3 ppm (6H), 3.2 to 3.95 ppm 
(4H, - CH.sub.2 - NCO), 4.0 to 4.7 ppm 
##STR5## 
Mass spectrum: m/c 153 
##STR6## 
267 (molecular weight). &lt;Polymerization of 2, 6-diisocyanate caproic acid 
-.gamma.-isocyanate propyl ester as a trifunctional isocyanate compound&gt; 
30 g (0.4 mole) of 3-aminopropanol and 100 ml of toluene were put in a 
four-mouthed flask fitted with a stirrer, a thermometer, a gas-introducing 
tube and a reflux condenser combined with a Dean-Stark apparatus; and by 
introducing into it hydrogen chloride gas, 3-aminopropanol was converted 
into a hydrochloride. Then, 36.6 g (0.2 mole) of lysine-monohydrochloride 
was added, and by introducing into the mixture hydrogen chloride gas 
again, it was converted into dihydrochloride of lysine. The reacting 
mixture was heated to the reflux temperature (110.degree. C.) and, 
meanwhile, hydrogen chloride gas was passed through it. After the lapse of 
11 hours, azeotropic distillation of water stopped. Toluene was eliminated 
from the resultant product, and ethanol was added to the residual oil-like 
substance and a heat was applied to the mixture. When such product was let 
to stand at room temperature, there was a deposition of crystals. By 
filtering out these crystals, 47 g of trihydrochloride mononhydrate of 
lysine-.gamma.-aminopropyl ester having a melting point of 138.degree. to 
145.degree. C., recrystallized from a mixture of methanol and ethanol, was 
obtained. 
In the next place, 25 g of desiccated powder of trihydrochloride 
monohydrate of lysine-.gamma.-aminipropyl ester, polymerized as above, and 
300 ml of o-dichlorobenzene were put in a four-mouthed flask provided with 
a stirrer, a thermometer, a gas-introducing tube and a reflux condenser so 
as to form a suspension. Maintaining the temperature of the suspension at 
150.degree. C., phosgen was passed through it at a rate of 0.4 mole/hr. 
for 10 hours. In the next place, the temperature was gradually raised to 
150.degree. C., and the reaction was let to progress at such temperature 
for 4 hours. After cooling, the liquid was filtered and the solvent was 
eliminated by distillation under reduced pressure. The residue was made to 
undergo a molecular distillation. The product: 7.2 g (yield 34%) of lysine 
diisocyanate -.gamma.-isocyanate propyl ester (2, 6-diisocyanate caproic 
acid -.gamma.-isocyanate propyl ester) (hereinafter called "LTI-P" for 
short) with a boiling point of 153.degree. to 155.degree. C./0.036 mmHg, a 
light yellow liquid. Viscosity: 28 cps/ 20.degree. C. NCO content: 44.6% 
by wt. (calculated value 44.8% by wt.). 
Infrared spectrum: 2225 cm.sup.-1 (isocyanate group), 1740 cm.sup.-1 (ester 
carbonyl), 1458, 1350, 1200 cm.sup.-1 (ester ether). 
Nuclear magnetic resonance spectrum: 1.2 to 2.4 ppm (8H), 3.2 to 3.8 ppm 
(4H, - CH.sub.2 -NCO), 3.9 to 4.6 ppm 
##STR7## 
Mass spectrum: m/c 153 
##STR8## 
281 (molecular weight).

EXAMPLE 1 
In a reactor provided with a stirrer, a thermometer, a condenser and a 
nitrogen gas introducing tube, after having sealed up nitrogen gas in it, 
50 parts xylole and 50 parts butyl acetate were put, and the temperature 
was raised to 90.degree. to 95.degree. C. 
______________________________________ 
A mixture composed of: 
styrene 34.0 pts. 
n-butyl acrylate 38.0 pts. 
2-hydroxyethyl methacrylate 
23.4 pts. 
acrylic acid 0.4 pts. 
azobisisobutylonitrile 1.2 pts. 
______________________________________ 
was continuously dropped into the reactor over 3 hours, for polymerizing 
reaction. After having finished dropping the mixture of monomers, the 
compound was stirred for 1 hour while it was heated. Thereafter, 0.7 part 
of azobisisobutylonitrile was added 4 times at an interval of 30 minutes, 
and the compound was stirred for another hour to complete the whole 
reaction. 
A resin solution thus obtained (a solution of polyacryl polyol) was 
colorless and transparent. Its Gardener bubble viscosity was "T" to "U" at 
25.degree. C., and the content of nonvolatile matter 50%. The molecular 
weight (Mn) was 14500; value of hydroxyl group 50; and calculated value of 
mean number of hydroxyl groups in a molecular 25.8. 
This resin solution and LTI-E, which had been previously prepared, were 
uniformly blended in such a manner that the amounts of hydroxyl and 
isocyanate groups are equal. To this blended solution, a mixed thinner 
composed of toluole and cellosolve acetate, in the ratio of 65/35 pct. by 
wt., was added to adjust the fluidity to 20 sec. at +4 of the Ford cup. 
This diluted coating material was applied by spraying on a mild steel 
sheet previously coated with primer surfacer No. 114 (mfrd. by Kansai 
Paint Co.) and polished, in such a manner that the film thickness after 
drying would be approximately 40.mu., and the coat was let to harden at 
room temperature (23.degree. C.) for a week. The film coat obtained was, 
as is shown in Table 1, hard and had an excellent resistance to acid and 
hot water. In respect of anti-yellowing property, too, it was equal to a 
coat obtained by the use of non-yellowing type isocyanate prepolymers on 
the market. 
The concentration of carbamide group was 15.7.times.10.sup.-4 moles/g.; 
bridging parameter 501; and the percentage of hydrocarbon solvent in the 
solvents contained in the coating material 59. 
EXAMPLE 2 
A coat was formed in the same manner as Example 1, except for, in this 
example, the mixing ratio of polyacryl polyol solution and LTI-E was so 
modified as to make the NCO/OH mole percentage 0.5. Properties and 
efficiency of the coat obtained are shown in Table 1. 
The concentration of carbamide group was 8.4.times.10.sup.-4 moles/g.; 
bridging parameter 947; and the percentage of hydrocarbon solvent in the 
solvents contained in the coating material 59. 
EXAMPLE 3 
A coat was formed in the same manner as Example 1, except for, in this 
example, the mixing ratio of polyacryl polyol solution and LTI-E was so 
modified as to make the NCO/OH mole percentage 1.5 Properties and 
efficiency of the coat obtained are shown in Table 1. 
The concentration of carbamide group was 22.0.times.10.sup.-4 mole/g.; 
bridging parameter 558; and the percentage of hydrocarbon solvent in the 
solvents contained in the coating material 58. 
EXAMPLE 4 
In the same reaction apparatus as was used in Example 1, after having 
sealed up nitrogen gas in it, 80 parts xylole and 20 parts butyl acetate 
were put, and the temperature was raised to 80.degree. to 85.degree. C. 
A monomer mixture composed of: 
______________________________________ 
A monomer mixture composed of: 
styrene 25.0 pts. 
methyl methacrylate 25.0 pts. 
n-butyl methacrylate 21.0 pts. 
n-butyl acrylate 14.0 pts. 
2-hydroxyethyl methacrylate 
12.0 pts. 
acrylic acid 0.6 pts. 
azobisisobutylonitrile 1.2 pts. 
______________________________________ 
was continuously dropped into the reactor over 3 hours. With the dropping 
finished, the compound was heated and stirred for 2 hours. Subsequently, 
0.5 parts of azobisisobutylonitrile was added to the compound 4 times at 
an interval of 2 hours, and the compound was further heated and stirred 
for 3 hours to complete the whole polymerization reaction. 
A resin solution thus obtained was colorless and transparent. Its Gardener 
bubble viscosity (25.degree. C.) was "V" to "W", and the content of 
nonvolatile matter 50%. The molecular weight (Mn) was 11700; value of 
hydroxyl group 25; and calculated value of mean number of hydroxyl groups 
in a molecule 10.4. 
With this resin solution, a coating material as prepared applied and was 
let to harden in the same manner as Example 1. As shown in Table 1, a coat 
having a good luster, with satisfactory rise of hardness, an excellent 
resistance to acid and hot water, was obtained. In respect of 
anti-yellowing property, too, the coat was as good as one obtained by the 
use of non-yellowing type isocyanate prepolymers available on the market, 
that is, no yellowing was observed. 
The concentration of carbamide group was 8.4.times.10.sup.-4 moles/g.; 
bridging parameter 1.067; and the percentage of hydrocarbon solvent in the 
solvents contained in the coating material 71. 
EXAMPLE 5 
To the resin solution obtained in Example 4, LTI-P, which had been 
previously prepared by polymerization, was added in such a manner that the 
amounts of hydroxyl and isocyanate groups are equal, and these were 
uniformly mixed together. 
With this mixture, a coating material was prepared, applied and was let to 
harden in the same manner as Example 1. Properties and efficiency of the 
coat obtained are shown in Table 1. 
The concentration of carbamide group was 8.5.times.10.sup.-4 moles/g.; and 
bridging parameter 1031. 
Control 1 
A coat was formed in the same manner as Example 1, except for, in this 
case, the mixing ratio of polyacryl polyol solution and LTI-E was so 
modified as to make the NCO/OH mole percentage 2.50. Efficiency of the 
coat obtained is shown in Table 1. 
The concentration of carbamide group was 32.4.times.10.sup.-4 moles/g.; and 
bridging parameter 633. 
Control 2 
A coat was formed in the same manner as Example 4, except for, in this 
case, the mixing ratio of the resin solution and LTI-E was so modified as 
to make the NCO/OH mole percentage 0.5. Efficiency of the coat obtained is 
shown in Table 1. 
The concentration of carbamide group was 4.4.times.10.sup.-4 moles/g.; and 
bridging parameter 1,999. 
Control 3 
A coat was formed in the same manner as Example 5, except for, in this 
case, the mixing ratio of the resin solution and LTI-P was so modified as 
to make the NCO/OH mole percentage 0.5. Efficiency of the coat obtained is 
shown in Table 1. 
The concentration of carbamide group was 4.4.times.10.sup.-4 moles/g.; and 
bridging parameter 1,966. 
TABLE 1 
__________________________________________________________________________ 
Example 
Example 
Example 
Example 
Example 
Control 
Control 
Control 
Examples or Controls 1 2 3 4 5 1 2 3 
Isocyanate Compounds LTI-E 
LTI-E 
LTI-E 
LTI-E 
LTI-E 
LTI-E 
LTI-E 
LTI-E 
Items for Assessment 
__________________________________________________________________________ 
"Weathaometer" 
Weather resistance 
2500 hrs. .circleincircle. 
O .about. .circleincircle. 
O O O X X X 
Exposure outdoors 
2 years .circleincircle. 
O .about. .circleincircle. 
O O O .DELTA. .about. X 
XX XX 
Gloss value, 60.degree. 
90 -- -- 95 -- -- -- -- 
Lead pencil hardness 3H -- -- 2H -- -- -- -- 
Shock resistance, 1 kg 
35 cm 
-- -- 20 cm 
-- -- -- -- 
Erichsen test 6.0 -- -- 7.5 -- -- -- -- 
Cross-cut adhesion property 
100/100 
-- -- 100/100 
-- -- -- -- 
Hot water resistance, 50.degree. C. .times. 24 hrs 
O -- -- O -- -- -- -- 
Acid resistance, 40 vol. % H.sub.2 SO.sub.4, 
55.degree. C. .times. 5 hrs 
O .about. .DELTA. 
-- -- O -- -- -- -- 
Naphtha No.5/toluole; 
(6) (4) 
Solvent resistance 
dipped for 10 min. 
O -- -- O -- -- -- -- 
"Xyloler" rubbing, 
30 times O -- -- O .about. .DELTA. 
-- -- -- -- 
0 hr 1.3 -- -- 3.1 -- -- -- -- 
Yellowness 
UV * 
200 hrs 9.1 -- -- 12.2 -- -- -- -- 
Yellowing deg. 
200 hrs 7.8 -- -- 9.0 -- -- -- -- 
Color difference 
200 hrs 
.DELTA. E(Lob) 4.7 -- -- 5.5 -- -- -- -- 
__________________________________________________________________________ 
* "Toshiba" Sterilizing Lamp GL15 (15W), wave length 254 nn; strength of 
radiation at a distance of 20 cm = 600 .mu.w/cm.sup.2. 
Pigment mixed: PWC 50%. 
Hardening: A week, at room temperature (23.degree. C.). 
Legend: 
.circleincircle. = Very good; 
O = Good; 
.DELTA. = Somewhat poor; 
X = Poor 
XX = Very Poor; 
-- = Not yet measured. 
EXAMPLE 6 
Polyester polyol was prepared in the following manner: 
______________________________________ 
A mixture composed of: 
neopentyl glycol 150.0 pts. 
trimethylol propane 22.1 pts. 
adipic acid 72.3 pts. 
isophthalic acid 123.2 pts. 
______________________________________ 
was put in a reactor and was stirred for 30 minutes while heating it at 
200.degree. C. Then, until it reached an acid value of 10 and a CH value 
of 150, heating and stirring were continued at a temperature of 
220.degree. C., thus distilling water (approx. 15 hrs.). The molecular 
weight of the reaction product obtained was approximately 1000. By adding 
butyl acetate to this reaction product while it is being cooled, a 
solution with 70% solid matter content--a polyester polyol solution--was 
prepared. 
In the next place, LTI-E was added to this polyester polyol solution in 
such a manner that the amounts of hydroxyl and isocyanate groups are 
equal, and these were uniformly mixed together. The calculated value of 
the concentration of carbamide group of this reaction product was 
21.8.times.10.sup.-4, and the calculated value of bridging parameter 
E.sub.c 790. 
A film coat which was obtained by applying this coating mixture and letting 
it harden had an excellent luster and very good mechanical properties. 
The percentage of hydrocarbon solvent in the solvents contained in said 
coating material was 48. 
EXAMPLE 7 
A two component type polyurethane coating consisting of "A" and "B" 
liquids, as undermentioned, was prepared. 
"A" liquid: 171.6 parts polyacryl polyol of Example 1 and 57.2 parts 
titanium oxide were kneaded in a three-roller kneading machine to form a 
paste. 
"B" liquid: 7.8 parts xylole was added to 14.2 parts LTI-E to form a 
triisocyanate solution with an NCO content of 30 wt.%. 
By mixing equal amounts of "A" and "B" liquids, a mixture of NCO/OH=1 was 
obtained. By adding a thinner (toluole/cellosolve acetate=65/35 wt.pct.) 
to this mixture, the fluidity was adjusted to 15 sec. of the Ford cup #4. 
The content of nonvolatile matter in the solution was 55%. This diluted 
solution was applied by spraying on a mild steel sheet previously coated 
with a primer surfacer and polished, such as was used in Example 1, in 
such a manner that the film thickness after drying would be approximately 
40.mu., and the material was heated at 60.degree. C. for 30 minutes. The 
coat obtained had a good luster and was superior in respect of acid and 
solvent resistance, too. The gloss retention after exposure out-doors for 
18 months was approximately 70%, thus proving to have a very good weather 
resistance. 
Concentration of carbamide group: 15.7.times.10.sup.-4 moles/g. 
Bridging parameter: 501 
Percentage of hydrocarbon in the solvents: 57.1%. 
EXAMPLE 8 
To 14.2 parts LTI-E of the "B" liquid in the case of Example 7, methyl 
ethyl ketoxime in an amount equal to that of NCO group was added, and the 
mixture was stirred for 5 hours at room temperature to block NCO group of 
LTI-E. By adding 7.8 parts xylole to this blocked isocyanate, a 
triisocyanate solution with an NCO content of 30 wt.% at the time of 
dissociation was prepared. 
By mixing this solution with "A" liquid of Example 7, a one-liquid type 
polyurethane coating was prepared. 
The coating material was diluted with a thinner, and was applied on the 
base material in the same manner as Example 7. After the coating had set, 
the material was heated at 150.degree. C. for 30 minutes to form a 
finished coat. The polyurethane resin coat obtained had a superior luster 
and showed a satisfactory weather resistance.