Polyazetidinol containing materials

An organic compound having at least two azetidinol moieties per molecule is prepared from a polyamine and an epihalohydrin. A reaction product is prepared by reacting a polycarboxylic acid group containing polymeric material with the organic compound having at least two azetidinol moieties. The organic compound and reaction product can be formulated into curable compositions both as a film forming vehicle or alternatively as an additive to improve mar and humidity resistance.

CROSS REFERENCE TO RELATED APPLICATIONS 
The present application is related to U.S. patent application Ser. No. 
07/814,656 filed on Dec. 30, 1991, entitled Azetidinol Reaction Products. 
BACKGROUND OF THE INVENTION 
The present invention relates to azetidinol containing materials having at 
least two azetidinol moieties per molecule and reaction products and 
curable compositions prepared therewith. 
In U.S. patent application Ser. No. 07/814,656, filed Dec. 30, 1991 
entitled Azetidinol Reaction Products, azetidinol containing materials 
having one azetidinol moiety per molecule are disclosed as grind vehicles 
for the preparation of a variety of pigmented coating compositions and 
also as modifiers for acrylic polymers and oligomers as well as other 
polymers and oligomers without the handling hazards associated with 
certain other small nitrogen ring containing materials. These modified 
materials, however, are non thermoset materials which require a 
crosslinking agent to produce a cured product. As a result, the curing 
process releases undesirable volatile byproducts of a curing reaction with 
aminoplast or polyisocyanate crosslinkers. 
Although quite advantageous, the modified azetidinols described above are 
limited in their applicability since they are incapable of 
self-crosslinking or reacting with other oligomers to form cured films 
without externally added crosslinking agents. 
The preparation of azetidinols with such properties would be desirable and 
advantageous. 
SUMMARY OF THE INVENTION 
In accordance with the present invention there is provided an organic 
compound having at least two azetidinol moieties per molecule. Also 
provided is a reaction product of the aforesaid organic compound with a 
polycarboxylic acid group containing polymeric material. 
In addition, there is provided a curable composition containing the 
aforesaid reaction product as a film forming vehicle or alternatively as 
an additive for improving mar and humidity resistance. 
DETAILED DESCRIPTION OF THE INVENTION 
The claimed organic compounds having at least two azetidinol moieties per 
molecule, polyazetidinols, are very advantageous not only as 
self-crosslinkable film forming binders but also as curing agents for 
other polymers and oligomers as well as additives and modifiers for a 
variety of solvent and waterborne coatings to improve overall film 
properties. For example, when used to form a reaction product with an acid 
functional oligomer or polymer, the reaction product is shelf stable and 
capable of self-crosslinking to form a film in about 30 minutes at a 
temperature of from about 180.degree. F. (82.degree. C.) to about 
250.degree. F. (121.degree. C.). The polyazetidinols are themselves shelf 
stable at ambient temperature for a period of several months or at 
elevated temperatures of about 140.degree. F. (60.degree. C.) for a week 
or more in either solvent or aqueous medium provided the pH is within the 
range of from about 6 to 9 under partial neutralization conditions of 5 to 
50 percent of amine. The polyazetidinols are capable of forming a film at 
temperatures of from ambient to about 400.degree. F. (205.degree. C.) for 
a period of from about 1 week to less than 30 minutes, respectively. The 
resultant films are clear and solvent resistant as measured by solvent 
rubs. 
In addition to their utility as film formers, the polyazetidinols described 
above are very advantageous as additives to waterborne, aminoplast 
curable, coating compositions in order to improve humidity resistance. It 
is theorized that this is accomplished because the hydroxyl groups of the 
polyazetidinol material react with and consume any residual carboxyl 
groups present which contribute to water sensitivity. 
The organic compounds of the present invention having at least two 
azetidinol moieties per molecule can be represented by the following 
structural formula 
##STR1## 
In the above formula n is an integer of from 2 to 4 and R is the residue 
derived from a polyfunctional amine. Examples of residues representative 
of R include alkylene, arylene, aralkylene, cycloalkylene or heteroatom 
substituted derivatives thereof. The amine is one of the reactants from 
which the polyazetidinol is prepared. The preferred amines are relatively 
hindered primary amines. By "hindered" is meant that the amino group is 
attached to a carbon that is in the vicinity of a bulky group. The other 
reactant is an epihalohydrin such as for example epichlorohydrin or 
epibromohydrin. Examples of polyfunctional amines include 
bis-4-(aminocyclohexyl) methane which is commercially available from 
Texaco Chemicals under the trademark M.RTM.-20; isophorone diamine; 
polyoxypropylene diamine which is commercially available from Texaco 
Chemicals as JEFFAMINE.RTM. D400 and JEFFAMINE.RTM. T403 which is a 
triamine derived from the reaction product of propylene oxide with a 
triol. 
The polyazetidinols having at least two azetidinol moieties per molecule 
generally can be prepared by the reaction of the polyfunctional amine with 
epihalohydrin followed by removal of hydrogen halide. The reaction is 
preferably conducted in the presence of a polar solvent such as butanol, 
acetonitrile, ethanol, isopropanol, methanol, dimethylformamine or 
dimethylsulfoxide. 
After the initial mixing, the polyfunctional amine and epihalohydrin are 
reacted at a temperature and for a period sufficient to form the 
hydrohalide salt of the polyfunctional azetidinol. Generally the reaction 
temperature ranges from about 60.degree. C. to about 80.degree. C. and the 
time of reaction ranges from about 1 to about 6 hours. 
Preferably, the hydrochloride salt of the polyazetidinol is converted to 
the free amine base by neutralization with aqueous sodium hydroxide. The 
product is then stripped to remove water and the salt removed by 
filtration to yield a solution of the polyazetidinol. 
The polyazetidinols of the present invention are capable of self 
crosslinking to form a cured film or they can be used to make gelled or 
ungelled reaction products with a variety of other oligomers and polymers. 
Also, they can be utilized as additives to waterborne, aminoplast curable 
coating compositions to improve mar and humidity resistance. 
Useful compositions containing the polyazetidinols can be prepared by 
blending the polyazetidinol with a carboxylic acid group containing 
polymeric material. For example, when the carboxylic acid group containing 
polymeric material is an acrylic polymer, the polymer can be prepared by 
addition of monomer and initiator to a solvent charge under reflux 
conditions over a period of about I to 5 hours. Upon completion of the 
monomer and initiator feed, the polymer is neutralized with an appropriate 
base either at ambient temperature or elevated temperature so long as the 
temperature is below the boiling point of the solvent and the base. 
Finally, the polyazetidinol is added at ambient temperature to yield the 
ungelled product. These compositions can then be further used to prepare 
coating films by curing the material by baking at elevated temperature. 
The polyazetidinols can also be utilized as curing agents for a variety of 
other polymeric materials. 
Examples of suitable materials which can be cocured with the 
polyazetidinols include vinyl addition polymers prepared from the vinyl 
addition polymerization of vinyl monomers, polyesters, polyethers, 
polyurethanes and polyamides. A detailed description of all of these 
materials is not felt to be necessary since one skilled in the art of 
coatings enjoys extensive knowledge of these materials. If additional 
information is desired reference is made to Kirk Othmer, Encyclopedia of 
Polymer Science and Technology, John Wiley and Sons, Inc. Copyright 1964. 
A preferred polymeric material is a carboxylic acid functional acrylic 
polymer which is described in further detail below. The aforesaid acrylic 
polymer can be prepared by the vinyl addition polymerization of a vinyl 
monomer component which comprises at least a portion of a carboxyl 
functional vinyl monomer. 
Examples of suitable carboxyl functional vinyl monomers include acrylic 
acid, methacrylic acid, monoesters of unsaturated dicarboxylic acids such 
as maleic acid, fumaric acid, and itaconic acid, for example, 
mono(hydroxyethyl) and mono(hydroxypropyl) esters of maleic acid. The 
balance of the vinyl monomer component can include a variety of other 
vinyl monomers which contain polymerizable vinyl unsaturation. For 
example, hydroxyl functional vinyl monomers such as 2-hydroxyethyl 
acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 
2-hydroxypropyl methacrylate and 2-hydroxybutyl methacrylate. Also useful 
are acrylamide; N-methylolacrylamide and N-alkoxymethyl acrylamides such 
as N-ethoxymethyl acrylamide and N-butoxymethylacrylamide; 
tertiary-butylaminoethyl methacrylate; sulfoethyl methacrylate; and alkyl 
acrylates and methacrylates which contain from 1 to 18 carbon atoms in the 
alkyl portion such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl 
(meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl 
(meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl 
(meth)acrylate, stearyl (meth)acrylate, isodecyl (meth)acrylate and 
isobornyl (meth)acrylate. Also useful are styrene, para-methyl styrene, 
alpha-methyl styrene, acrylonitrile, methacrylonitrile and vinyl esters 
such as vinyl acetate or vinyl versatate. Mixtures of the aforesaid 
monomers can also be utilized. Preferably, the acrylic polymer has a 
number average molecular weight ranging from about 500 to about 50,000, 
more preferably about 2000 to about 20,000. 
Preparation of the vinyl addition polymer is usually coriducted at a 
temperature within the range of about 25.degree. C. to about 250.degree. 
C., preferably 85.degree. C. to 160.degree. C. There is generally present 
a free radical initiator which is selected from a wide variety of 
materials. Suitable types of materials include peroxides, hydroperoxides 
and azo initiators. Examples of these types of initiators include 
di-tertiary butyl peroxide, di-cumyl peroxide; amyl peroxyacetate; cumene 
hydroperoxide; 2,5-dimethyl-2,5-bis(tertiary butyl peroxy)hexane; 
hexyne-3-tertiary butyl cumyl peroxide; tertiary amyl peroxide; 
2,5-dihydroperoxy 2,5-dimethylhexane; di(n-propyl)peroxydicarbonate and 
2,2'-azobis(2,4-dimethyl-4-methoxy-valeronitrile). Also suitable are Redox 
initiators such as the combination of hydrogen peroxide and isoascorbic 
acid. Transition metals such as iron are usually used as coinitiators with 
a Redox initiator system. 
The type and amount of initiator will be selected depending upon the 
molecular weight desired and/or the final form of the polymeric species, 
i.e., solvent soluble form or dispersed form in aqueous or non-aqueous 
media. The amount of initiator can vary widely although usually it is 
present in an amount ranging from about 0.1 percent to about 80 percent, 
the percent based on the total weight of the vinyl monomer component. 
Generally, there can also be present during the vinyl addition 
polymerization a solvent. Examples of these solvents include ketones such 
as methyl amyl ketone, aromatic petroleum distillates, esters such as 
butyl acetate, heptyl acetate and 2-ethylhexyl acetate, and high boiling 
ester solvents such as those commercially available from Exxon Chemical 
Corporation under the trademark designations EXTATE 600 and EXTATE 700. 
It should be understood that the carboxylic acid functional acrylic 
polymers may also be prepared by conventional suspension, emulsion and 
non-aqueous dispersion polymerization techniques. 
The polyazetidinols of the present invention form crosslinked films either 
alone or in the presence of other film forming components. Film formation 
may be accomplished at room temperature or under baking conditions, as a 
solvent based or water based system. The cured films are mar resistant. 
A curable composition can also be prepared from the polyazetidinols 
detailed above in conjunction with a base neutralized acid functional 
waterborne dispersion or solution polymer. This composition can be applied 
and cures well at a temperature of 200.degree. F. (93.degree. C.) to 
300.degree. F. (149.degree. C.) for a period of about 30 minutes. Examples 
of suitable base neutralized acid functional waterborne solution or 
dispersion polymers include base neutralized acid functional polyesters, 
acid functional polyester urethanes, acid functional acrylates and acid 
functional urethane-acrylates. The preparation of these materials is well 
understood by those skilled in the art of polymer chemistry. If additional 
details are desired reference is made to Kirk Othmer, Encyclopedia of 
Polymer Science and Technology, John Wiley and Sons, Inc. Copyright 1964. 
The polyazetidinols of the present invention are also advantageous as 
additives for aqueous based coating compositions to improve humidity 
resistance. For example, the polyazetidinols can be combined with a 
waterborne film forming vehicle and an aminoplast crosslinking agent. 
Such curable (crosslinkable) or thermosetting compositions can be 
formulated as clear coats or optionally they can contain a pigment. The 
pigments can be any of the conventional types comprising, for example, 
iron oxides, lead oxides, strontium chromate, carbon black, coal dust, 
titanium dioxide, talc, barium sulfate, as well as the color pigments such 
as cadmium yellow, cadmium red, chromium yellow, phthalocyanine blue, 
toluidine red, and the metallic pigments such as aluminum flake and metal 
oxide encapsulated mica. When used, the pigment content of the coating 
composition is expressed as a pigment to resin weight ratio, and is 
usually within the range of about 0.05 to 3.0:1. 
In addition, other optional ingredients such as adjuvant hydroxy-containing 
polymers, fillers, plasticizers, catalysts, reactive diluents, 
anti-oxidants, ultraviolet light absorbers, flow control agents, and other 
formulating additives can be employed if desired. 
Curable compositions of the invention can be applied as film forming 
coatings to a variety of substrates such as wood, metal, glass, cloth, 
plastic, foams and the like by a variety of application techniques such as 
air spraying, airless spraying, dipping, brushing and flow coating. The 
coating compositions are useful as basecoats or clearcoats and are 
particularly desirable as topcoat compositions for automobiles and trucks 
either as original finishes or as refinish coatings. Also, the coating 
compositions can be applied as color plus clear in basecoat-clearcoat 
applications. 
The following examples are illustrative of the invention and are not 
intended to be limiting.

EXAMPLE 1 
Synthesis of bis-azetidinol functional material based on 
bis-4(aminocyclohexyl) methane (AM.RTM.-20 diamine commercially 
available from Texaco Chemicals): 
______________________________________ 
Charge Amount 
______________________________________ 
AM-20 210.0 g 
n-butanol 710.0 g 
Feed A: 
Epichlorohydrin 185.0 g 
Feed B: 
Sodium hydroxide 80.0 g 
Deionized water 80.0 g 
______________________________________ 
Feed A was added under agitation over 30 minutes into a 5 liter flask 
containing the charge. The contents of the flask were then heated to 
60.degree. C., and held at that temperature until the acid value (the acid 
value is the number of milligrains of potassium hydroxide required to 
neutralize the free acid present in one gram of the material) reached the 
theoretical value. The product thus formed was cooled to room temperature, 
followed by the addition of Feed B. The temperature was kept below 
30.degree. C. during the addition of Feed B. 
The final product was isolated in N-butanol by filtering off the sodium 
chloride salt and removing the water by azeotropic distillation. The 
product had following physical properties: total solids=41.0%, acid value 
=0.5, molecular weight determined by gel permeation chromatography using a 
polystyrene standard (GPC)=321, epoxy equivalent weight=infinite, pH in 
water-butanol mixture=11.2. The formation of the product was also 
identified by 13.sub.C and 1.sub.H nuclear magnetic resonance (nmr) 
spectroscopy. 
EXAMPLE 2 
Synthesis of bis-azetidinol based on isophorone diamine: 
This product was prepared in the same manner as the bis-azetidinol of 
Example I except that AM-20 was replaced by isophorone diamine on a 
molar basis. The product had the following physical properties: total 
solids=42.0%, acid value=1.0, molecular weight by GPC=454.5, epoxy 
equivalent weight=infinite, pH in butanol-water mixture=11.4. 
EXAMPLE 3 
Synthesis of bis-azetidinol based on polyoxypropylene diamine 
(JEFFAMINE.RTM. D-400 which is commercially available from Texaco 
Chemicals): 
______________________________________ 
Charge Amount 
______________________________________ 
JEFFAMINE D-400 465.0 g 
Acetonitrile 930.0 g 
Feed A: 
Epichlorohydrin 185.0 g 
Feed B: 
Toluene 930.0 g 
Feed C: 
Sodium hydroxide 80.0 g 
Deionized water 80.0 g 
______________________________________ 
Feed A was added over 30 minutes at room temperature into the charge in a 5 
liter flask. The contents of the flask were then heated slowly to 
75.degree. C. and held at this temperature until the acid value reached 
the theoretical value. Afterwards, solvents were removed by distillation, 
followed by addition of Feed B. The product was cooled to room temperature 
and Feed C was added. The sodium chloride salt, thus formed, was removed 
by filtration. The product was isolated in toluene by removing water by 
azeotropic distillation. 
The final product had the following physical properties: total solids 70% 
in toluene, acid value=1.0, epoxy equivalent weight=infinite, weight 
average molecular weight by GPC=541. 
EXAMPLE 4 
Synthesis of tri-azetidinol functional material based on triamine derived 
from reaction product of propylene oxide with a triol. (JEFFAMINE.RTM. 
T-403 commercially available from Texaco Chemicals). 
This product was made in the same way as the bis-azetidinol based on 
JEFFAMINE.RTM. D-400 except that JEFFAMINE.RTM. D-400 was replaced by 
JEFFAMINE.RTM. T-403 on molar basis. 
EXAMPLE 5 
Stability of polyazetidinol functional materials at room temperature in a 
n-butanol-water mixture having pH greater than 11.0. 
______________________________________ 
Stability after 
Stability After 
Polyazetidinol 
4 Days 7 Days 
______________________________________ 
Example 1 Viscosity Increased 
Gelled 
Example 2 Viscosity Increased 
Gelled 
Example 3 Viscosity Increased 
Gelled 
Example 4 Gelled 
______________________________________ 
EXAMPLE 6 
This example presents data showing the stability of polyazetidinol 
materials at 120.degree. F. (49.degree. C.) after 1, 2 and 4 weeks (pH was 
adjusted to 10.1 by addition of acetic acid). Initial viscosity (before 
storage at 120.degree. F. (49.degree. C.)) is shown in parenthesis. 
______________________________________ 
Poly- Stability After 
Stability After 
Stability After 
azetidinol 
1 Week 2 Weeks 4 Weeks 
______________________________________ 
Example 1 
E (E) G J 
Example 3 
less than A less than A B-C 
(less than A) 
Example 4 
Gelled (E) Gelled Gelled 
______________________________________ 
All the viscosities were measured by Gardner viscosity test tubes at 
76.degree. F. 
EXAMPLE 7 
This example presents data showing the stability of polyazetidinol 
materials at 120.degree. F. (49.degree. C.) after 1,2, and 4 weeks (pH was 
adjusted to 8.1 by Addition of acetic acid). Initial viscosity is shown in 
parenthesis. 
______________________________________ 
Poly- Stability After 
Stability After 
Stability After 
azetidinol 
1 Week 2 Weeks 4 Weeks 
______________________________________ 
Example 1 
F (F) F-G H-I 
Example 2 
U (U) W Z 
Example 3 
less than A less than A A 
(less than A) 
Example 4 
Gelled (E) Gelled Gelled 
______________________________________ 
EXAMPLE 8 
This example presents data showing film forming properties of 
polyazetidinols after baking the films at 180.degree. F. (82.degree. C.). 
Films of 2.0 mil thickness were drawn on glass panels and baked for 15 
minutes at 180.degree. F. (82.degree. C.). The hardness of the films was 
determined by solvent resistance which was evaluated by wetting a piece of 
cloth with solvent and rubbing that solvent back and forth on the film 
until the film was removed. The results are presented as double rubs (DR) 
in the following table. 
______________________________________ 
Polyazetidinol 
Toluene N-Butanol Water 
______________________________________ 
Example 1 greater than 
25 DR 80 DR 
100 DR 
Example 2 greater than 
15 DR 80 DR 
80 DR 
Example 4 greater than 
5 DR 20 DR 
25 DR 
______________________________________ 
All these films were non-yellowing and transparent. 
EXAMPLE 9 
This example presents data showing film forming properties of 
polyazetidinols after baking the films at 230.degree. F. (110.degree. C.) 
for 1 hour. The hardness of the films was evaluated in the same way as in 
Example 8. Results are shown in the following table: 
______________________________________ 
Polyazetidinol 
Toluene N-Butanol Water 
______________________________________ 
Example 1 greater than 
greater than 
greater than 
125 DR 100 DR 120 DR 
Example 2 greater than 
greater than 
greater than 
120 DR 100 DR 120 DR 
Example 4 greater than 
greater than 
greater than 
75 DR 40 DR 60 DR 
______________________________________ 
Examples 8 and 9 show that the polyazetidinols of the present invention 
self-crosslink rapidly at elevated temperature forming films which are 
hard, non-yellowing and transparent. 
EXAMPLE 10 
This example shows the synthesis of a polyazetidinol functional acrylic 
polymer: 
______________________________________ 
Charge Amount 
______________________________________ 
n-butanol 200.0 g 
Feed A: 
Butyl acrylate 303.0 g 
Styrene 203.0 g 
Methyl methacrylate 400.0 g 
Acrylic acid 100.0 g 
Feed B: 
Tertiary butyl peracetate 
28.7 g 
n-butanol 92.7 g 
Feed C: 
Dimethyl ethanol amine 123.6 g 
Feed D: 
Deionized water 1400.0 g 
Feed E: 
AM based bis-azetidinol of Example 1 
298.4 g 
(37.0% solid in n-butanol) 
______________________________________ 
Charge was heated to reflux (about 117.degree. C.) under nitrogen 
atmosphere. Feed A was added over 3 hours and Feed B was added over 3.5 
hours. Upon the completion of Feed B, the contents of the flask were 
cooled below 100.degree. C. Feed C and Feed D were added at 90.degree. C. 
and 80.degree. C., respectively. Feed E was added after cooling the 
polymer to room temperature. 
The final product had the following physical properties: total solids 36.0% 
in water-n-butanol mixture, pH=9.02, viscosity=37,000 centipoise, number 
average molecular weight by GPC=13,494, weight average molecular weight by 
GPC=36,124, the average particle size=133 nanometer. 
EXAMPLE 11 
This example presents data showing the film forming properties of the 
polyazetidinol functional acrylic polymer prepared in Example 10: 
The resin described in Example 10 was reduced to 25 percent solids with 
deionized water and then applied (using a 15-mil, number 24 wet film 
applicator from Paul N. Gardner Company, Inc) to four steel panels 
electrocoated with UNI-PRIME.RTM. primer, commercially available from PPG 
Industries, Inc. The coated panels were baked at 200.degree. F. 
(93.degree. C.), 250.degree. F. (121.degree. C.), 275.degree. F. 
(135.degree. C.) and 300.degree. F. (149.degree. C.) for 30 minutes. 
After baking, dry film thickness ranged from 1.8 to 2.0 mils and all of the 
films were glossy and transparent. The films were evaluated as follows: 
Gloss ranged from 80 to 90 degrees measured with a 20 degree angle Hunter 
Lab Glossmeter from Hunter Associates Laboratory, Inc. 
Distinctness of Image was between 60 and 75 as measured with a Glow-Box, 
model GB-11, commercially available from I.sup.2 R in Cheltenham, PA. 
The films demonstrated solvent resistance to 100 double rubs of methyl 
ethyl ketone, xylene and N-methyl-2-pyrolidone. Additionally, all the 
films exhibited H to 3H pencil hardness. 
Films baked at 200.degree. F. (93.degree. C.) and 250.degree. F. 
(121.degree. C.) showed no yellowing, however, films baked at 270.degree. 
F. (135.degree. C.) and 300.degree. F. (149.degree. C.) showed some 
yellowing.