U.S. patent application number 15/513460 was filed with the patent office on 2017-09-14 for ketimines of benzylated polyamines as curing agents.
The applicant listed for this patent is EVONIK DEGUSSA GMBH. Invention is credited to Kristen Elaine MINNICH, Marcelo RUFO, Gamini Ananda VEDAGE.
Application Number | 20170260322 15/513460 |
Document ID | / |
Family ID | 54325060 |
Filed Date | 2017-09-14 |
United States Patent
Application |
20170260322 |
Kind Code |
A1 |
MINNICH; Kristen Elaine ; et
al. |
September 14, 2017 |
KETIMINES OF BENZYLATED POLYAMINES AS CURING AGENTS
Abstract
Ketimines of benzylated polyamines and MEK are disclosed. The
ketimines can be used as an epoxy curing agent and impart improved
potlife, and enhanced blush and chemical resistance of cured epoxy
coatings.
Inventors: |
MINNICH; Kristen Elaine;
(Germansville, PA) ; RUFO; Marcelo; (San Paulo,
BR) ; VEDAGE; Gamini Ananda; (Bethlehem, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EVONIK DEGUSSA GMBH |
Essen |
|
DE |
|
|
Family ID: |
54325060 |
Appl. No.: |
15/513460 |
Filed: |
September 22, 2015 |
PCT Filed: |
September 22, 2015 |
PCT NO: |
PCT/US2015/051405 |
371 Date: |
March 22, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62053370 |
Sep 22, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07C 249/02 20130101;
C07C 251/08 20130101; C09D 163/00 20130101; C08G 59/50 20130101;
C08G 59/5033 20130101 |
International
Class: |
C08G 59/50 20060101
C08G059/50; C07C 251/08 20060101 C07C251/08; C09D 163/00 20060101
C09D163/00; C07C 249/02 20060101 C07C249/02 |
Claims
1) A compound comprising a ketimine of benzylated polyamines.
2) A method for making a ketimine of benzylated polyamines
comprising contacting at least one ketone with at least one
benzylated polyamine.
3) The method of claim 2 wherein the ketone comprises MEK.
4) The method of claim 2 wherein the contacting employs the
following formula: ##STR00003## Wherein R1 is benzyl, R2 is H,
alkyl, cycloaliphatic or benzyl R3 and R4 are (CH.sub.2), provided
that m=2-6; n=1-3; and R5 and R6 are C1-C10 linear or branched
aliphatic or cycloaliphatic or substituted cycloaliphatic
hydrocarbon or aromatic hydrocarbon, and R7 is H or C3-C10
containing linear or branched aliphatic or cycloaliphatic or
substituted cycloaliphatic hydrocarbon or aromatic hydrocarbon or
hydroxyl.
5) A composition comprising at least one ketimine of benzlyated
polyamines.
6) An epoxy curing agent comprising at least one ketimine of
benzylated polyamines.
7) The epoxy curing agent of claim 3 further comprising at least
one member selected from the group consisting of modified amines,
like, aliphatic amine adducts, cycloaliphatic amine adducts,
unmodified cycloaliphatic amine, Mannich Base, Phenalkamines,
Polyamides and Amidoamines.
8) A composition comprising at least one ketimine of benzylated
polyamines and at least one epoxy resin.
Description
[0001] This Application claims the benefit of Application No.
62/053,370, filed on Sep. 22, 2014. The disclosure of Application
No. 62/053,370 is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates to ketimines based on benzylated
polyamines and methyl ethyl ketone (MEK) and methods for making and
using the ketimines as epoxy curing agents.
BACKGROUND OF THE INVENTION
[0003] Ketimines are known as latent curing agents for many
applications and are especially useful in moisture rich
environments however; epoxy systems using ketimines based on
aliphatic amines have poor chemical resistance and are prone to
whitening or blushing. Benzylated polyamines have been shown to
provide chemical resistance and reduce blushing but their
reactivity can lead to short potlife when used as an epoxy curing
agent.
[0004] U.S. 2005/0010022A1 discloses a curing agent containing a
ketimine. Patent Applications disclosing benzylated polyamines as
curing agents include U.S. 2013/0079435A1, U.S. 2009/0163676A, U.S.
2009/0030125 and U.S. 2009/0023846A1 with benzylated polyamines
described as having at least three nitrogen atoms, at least three
active amine hydrogen atoms and at least one benzyl group.
JP111524434A describes the use of ketimine made with a combination
of MEK and methyl isobutyl ketone.
[0005] U.S. Pat. No. 6,573,357 describes a process for the
production of aliphatic ketimines using a decanter to separate
water from ketone.
[0006] The disclosure of the previously identified patents and
patent applications is hereby incorporated by reference.
BRIEF SUMMARY OF THE INVENTION
[0007] The instant invention solves problems associated with
conventional ketimines by providing ketimines of benzylated
polyamines and MEK. Ketimines of the present invention provide
improved potlife, blush and chemical resistance at ambient,
elevated or low temperatures. By "improved potlife" it is meant the
inventive ketimine have a working time that is longer than the
benzylated polyamines. By "improved blush and chemical resistance"
it is meant that an epoxy resin cured with the inventive ketimines
will not have amines migrating to the coatings surface and also
that the inventive ketimines provides chemical resistance against
some chemical agents where conventional ketiminies typically fails.
By "cured" it is meant that the inventive ketimine will properly
react with the epoxy resin at ambient or low temperature.
[0008] One aspect of the invention relates to a compound comprising
a ketimine of benzylated polyamines.
[0009] Another aspect of the invention relates to a method for
making a ketimine of benzylated polyamines comprising contacting at
least one ketone with at least one benzylated polyamine.
[0010] Another aspect of the invention to relates to any of the
foregoing aspects wherein the ketone comprises MEK.
[0011] A further aspect of the invention relates to any of the
foregoing aspects wherein the contacting employs the following
formula:
##STR00001##
[0012] Wherein R1 is benzyl, R2 is H, alkyl, cycloaliphatic or
benzyl, R3 and R4 are (CH.sub.2).sub.m provided that m=2-6; n=1-3;
and R5 and R6 are C1-C10 linear or branched aliphatic or
cycloaliphatic or substituted cycloaliphatic hydrocarbon or
aromatic hydrocarbon, and R7 is H or C3-C10 containing linear or
branched aliphatic or cycloaliphatic or substituted cycloaliphatic
hydrocarbon or aromatic hydrocarbon or hydroxyl.
[0013] One aspect of the invention relates to a composition
comprising at least one ketimine of benzlyated polyamines.
[0014] Another aspect of the invention relates to an epoxy curing
agent comprising at least one ketimine of benzylated
polyamines.
[0015] A further aspect of the invention relates to the foregoing
aspects and further comprising at least one member selected from
the group consisting of modified amines, like, aliphatic amine
adducts, cycloaliphatic amine adducts, unmodified cycloaliphatic
amine, Mannich Base, Phenalkamines, Polyamides and Amidoamines.
[0016] One aspect of the invention relates to a composition
comprising at least one ketimine of benzylated polyamines and at
least one epoxy resin.
[0017] The various aspects of the invention can be used alone or in
various combinations.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention relates to ketimines based on
benzylated polyamines and methyl ethyl ketone, and methods for
making the ketimines and methods for using the ketimines as epoxy
curing agents.
[0019] Ketimines of the instant invention can be produced by any
suitable method. In one aspect of the invention, the inventive
ketimines are a product of benzylated polyamines and ketones with
the following formula:
##STR00002##
[0020] R1 benzyl, R2 and can be H, alkyl, cycloaliphatic or benzyl,
R3 and R4 (CH.sub.2).sub.m m=2-6 preferred m=2 or 3 and n=1-3
Preferred n=1-2, R5, R6 C1-C10 linear or branched aliphatic or
cycloaliphatic or substituted cycloaliphatic hydrocarbon or
aromatic hydrocarbon. R7 is H or C3-C10 containing linear or
branched aliphatic or cycloaliphatic or substituted cycloaliphatic
hydrocarbon or aromatic hydrocarbon or hydroxyl. Preferred R5,
R6=C1-C4.
[0021] Ketone to benzylated polyamine ratio used for making the
inventive benzylated polyamines can range from about 1:1 to about
10:1, about 1:1 to about 5:1 and, in some cases, about 1:1 to about
1:1.5 equivalents of ketone to primary amine. The temperature can
range from about 75 to about 100, about 80 to about 95 and in some
cases about 80 to about 90 while using ambient pressure and a
nitrogen blanket. The inventive ketimine can be produced using
conventional equipment such as round bottomed flask fitted with a
nitrogen blanket, thermocouple and a condenser connected to a
Dean-Stark trap.
[0022] Benzylated polyamines are defined as the reaction product of
a benzaldehyde compound or benzyl halide compound with a
polyalkylene polyamine having at least three nitrogen atoms, at
least three active amine hydrogen atoms and at least one benzyl
group. Examples of benzylated polyamines comprise at least one
member selected from the group consisting of benzylated
polyethylene polyamines, benzylated polypropylene polyamines,
benzylated aminopropylated ethylenediamines and benzylated
aminopropylated propylenediamines and combinations thereof.
[0023] Ketones can comprise at least one member selected from the
group consisting of acetone, methyl ethyl ketone, methyl propyl
ketone, methyl isopropyl ketone, methyl butyl ketone, methyl
isobutyl ketone, methyl n-amyl ketone, methyl isoamyl ketone,
methyl heptyl ketone, diethyl ketone, ethyl butyl ketone, ethyl
amyl ketone, diisopropyl ketone, diisobutyl ketone, cyclohexanone,
cyclopentanone, methyl cyclohexanone, isophorone, methyl t-butyl
ketone, 5-methyl-3-heptanone, 4-heptyl ketone,
1-phenyl-2-propanone, acetophenone, methyl nonyl ketone, dinonyl
ketone, 3,3,5 trimethyl cyclohexanone. Preferred ketones include
acetone, and methyl ethyl ketone.
[0024] Polyalkylene polyamine compounds that are useful in
producing the benzylated polyalkylene polyamine compounds of the
present invention comprise at least one member selected from the
group consisting of polyethylene polyamines, polypropylene
polyamines, aminopropylated ethylenediamines and aminopropylated
propylenediamines and combinations thereof. Non-limiting examples
of polyethylene polyamines include diethylenetriamine (DETA),
triethylenetetramine (TETA), tetraethylenepentamine (TEPA),
pentaethylenehexamine (PEHA), and other higher polyethylene
polyamines. Suitable polypropylene polyamines include,but are not
limited to, dipropylenetriamine, tripropylenetetramine, and other
higher polypropylene polyamines. Aminopropylated ethylenediamines
and aminopropylated propylenediamines include, but are not limited
to, N-3-aminopropyl ethylenediamine (Am3);
N,N'-bis(3-aminopropyl)ethylenediamine (Am4);
N,N-bis(3-aminopropyl)ethylenediamine;
N,N,N'-tris(3-aminopropyl)ethylenediamine (Am5);
N,N,N',N'-tetrakis(3-aminopropyl)ethylenediamine;
N-3-aminopropyl-1,3-diaminopropane;
N,N'-bis(3-aminopropyl)-1,3-diaminopropane;
N,N-bis(3-aminopropyl)-1,3-diaminopropane;
N,N,N'-tris(3-aminopropyl)-1,3-diaminopropane;
N,N,N',N'-tetrakis(3-aminopropyl)-1,3-diaminopropane; and
aminopropylated higher alkylenediamines. Mixtures of APADA
compounds can be employed in the present invention. Processes for
using the polyalkylene polyamine for making benzylated polyalkylene
polyamine are disclosed in U.S. 2013/0079435A1, U.S. 2009/0163676A,
U.S. 2009/0030125 and U.S. 2009/0023846A1; hereby incorporated by
reference.
[0025] It will be recognized by those skilled in the art that
polyethylene polyamines containing 4 or more nitrogens are
generally available commercially as complex mixtures, most of which
contain the same number of nitrogens. Side products in these
mixtures are often called congeners. For example, TETA contains not
only linear TETA, but also tris-aminoethylamine,
N,N'-bisaminoethylpiperazine, and
2-aminoethylaminoethylpiperazine.
[0026] In one aspect of the present invention, at least one
polyalkylene polyamine compound is DETA, TETA, TEPA, PEHA,
dipropylenetriamine, tripropylenetetramine or any combination
thereof.
[0027] In another aspect, the at least one polyalkylene polyamine
compound is DETA, or TETA, or a mixture of DETA and TETA. Typical
mixtures of DETA and TETA are I part by weight of DETA to about 0.1
to about 1.1 parts by weight of TETA. In this and other aspects of
the present invention, the mixtures of DETA and TETA can be I part
by weight of DETA to about 0.1 about 0.2, about 03, about 0.4,
about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0,
or about 1.1 parts by weight of TETA. For example, DETA/TETA weight
ratios of 70/30 and 50/50 are useful in the present invention.
[0028] The reaction of ketones with amines results in the
generation of water as a by-product. When using ketones with high
water solubility, the amount of water generated can be such that
water does not readily separate from the reaction mixture. By high
water solubility it is meant ketones containing less than 6 carbon
atoms. Without wishing to be bound by any theory or explanation, it
is believed that equilibrium with water can be reached thereby
inhibiting the ketimine formation reaction from going to
completion. The inventive method for making the inventive ketimines
solves this problem by employing a co-solvent to separate water
from the ketone thereby providing the ability to drive the reaction
to completion and to recycle the solvent/ketone mixture. The ratio
of co-solvent to ketone can range from about 1:1 to about 10:1,
about 1:1 to about 1:5 and in some cases about 1:1 to about
1:2.
[0029] While any suitable co-solvent can be employed, example of
suitable co-solvents can include hydrocarbons such as at least one
member selected from the group consisting of pentane, hexane,
heptane, octane, nonane, cyclohexane, acetonitrile, toluene, and
xylene.
[0030] The inventive ketimine can have an amine equivalent weight
(AEW) ranging from about 85 to about 91, about 86 to about 92 and
in some cases about 88 to about 94.
[0031] The inventive process for making the inventive ketimine can,
in some aspects, be substantially free of methylisobutylketone. By
"substantially free" it is meant that the inventive ketimie and the
process for making the inventive ketimine contains less than about
5wt %, less than about 3wt. % and typically about 0wt % of
methylisobutylketone.
[0032] The inventive ketimine can be employed as a curing agent for
epoxy resins. Examples of epoxy resins that can be cured with the
inventive ketimine comprise at least one member selected from the
group consisting of Diglycidil Ether of Bisphenol A (DGEBPA) or
Diglycidil Ether of Bisphenol F (DGEBPF) or Epoxy Novolac Resin.
The ratio of ketimine to epoxy can range from about 5% to about
30%, about 5% to about 50% and, in some cases about 1% to about
90%. One aspect the invention relates to curable composition
comprising about 5% to about 100% of the inventive ketime, and
about 10% to about 90% of epoxy resin.
[0033] In one aspect of the invention, the inventive ketimine is
combined with another curing agent comprising at least one member
selected from the group consisting of modified amines, like,
aliphatic amine adducts, cycloaliphatic amine adducts, unmodified
cycloaliphatic amine, Mannich Base, Phenalkamines, Polyamides or
Amidoamines. The ratio of inventive ketimine to other curing agents
can range from about 3% to about 90%, about 10% to about 80% and in
some cases about 20% to about 70%. One aspect of the invention
relates to a curing agent composition comprising about 5% to about
95% inventive ketime, and about 95% to about 5% of the foregoing
amine curing agents.
[0034] The inventive curing agent can be combined with an epoxy
resin by using any suitable equipment and methods. Examples of
suitable equipment and methods comprise high speed mixer, cowles or
hand-mix.
[0035] The inventive curing agent can be combined with Epoxy
Novolac Resins, or any other Epoxy resin containing more than 2
oxyrane rings per molecule in order to produce cured epoxy coatings
having a Tg that can range from about 50 C to about 120 C, about 55
C to about 100 C and in some cases about 40 C to about 90 C. Cured
epoxy coatings or films obtained by using the inventive curing
agent can have a gloss value ranging from about 5 to about 50,
about 10 to about 70 and in some cases about 20 to about 100; a
tack and blush on a scale of 0-5 ranging from about 0 to about 3;
and dry times from about 1 hour to about 72 hours.
[0036] The following examples are provided to illustrate certain
aspects of the invention and do not limit the scope of the claims
appended hereto.
EXAMPLES
Example 1
Preparation of Inventive Ketimine with Water Insoluble Ketone
[0037] Benzylated polyamine (250 g) was weighed into a round
bottomed flask fitted with a nitrogen blanket, thermocouple and a
condenser connected to a Dean-Stark trap. Methyl isobutyl ketone
(MIBK) (289 g) was added allowing the mixture to heat to 40 C. When
addition was complete the mixture was heated to reflux, water/MIBK
collected in the trap, where water phase separated from MIBK and
MIBK was returned to the reaction flask. When water collection
stopped the condenser/trap was replaced by a distillation head and
excess ketone were removed by distillation. A reaction product was
analyzed using GC/MS and confirmed that ketimine was formed.
Example 2
Preparation of Inventive Ketimine with Water Soluble Ketones
[0038] Benzylated polyamine (200 g) and heptane (85 g) were weighed
into a round bottomed flask fitted with a nitrogen blanket,
thermocouple and a condenser connected to a Dean-Stark trap. Methyl
ethyl ketone (MEK) (169 g) was added allowing the mixture to heat
to 35 C. When addition was complete the mixture was heated to
reflux, water/MEK/heptane collected in the trap, where water phase
separated from MEK/heptane and MEK/heptane was returned to the
reaction flask. When water collection stopped the condenser/trap
was replaced by a distillation head and excess ketone and heptane
were removed by distillation. Final product amine equivalent weight
(AEW, defined as grams per N) value 90 was determined by titration
using perchloric acid. A reaction product was analyzed using GC/MS
and confirmed that ketimine was formed.
Example 3
Comparative Example Using Water Soluble Ketones Without
Co-Solvent
[0039] Benzylated polyamine (200 g) was weighed into a round
bottomed flask fitted with a nitrogen blanket, thermocouple and a
condenser connected to a Dean-Stark trap. Methyl ethyl ketone (169
g) was added allowing the mixture to heat to 35 C. When addition
was complete the mixture was heated to reflux. Water did not
separate from MEK in the trap and had to be removed by distillation
with MEK. Final product had an AEW value of 83 indicating a
relatively low conversion in comparison to Example 2.
Example 4
Preparation and Testing of Coatings
[0040] A curable epoxy resin was prepared by mixing ketimine with
commercially available diglycidyl ether of bisphenol A (epoxy
equivalent weight approx 190 Dow Epoxy Resin DER 331) in
proportions listed in Table 1. A high speed mixer was used for
mixing at an 600 rpm.
TABLE-US-00001 TABLE 1 Formulations Raw Material 1 2 3
Ethylenediamine-MIBK Ketimine 100 N,N'-1,2-Etanediylbis(1,3- 100
Propanediamine)-MIBK Ketimine Benzylated Polyamine-MIBK Ketimine
100 (Inventive Ketimine) AHEW 55 56 73.5 Phr with DER331 (EEW =
190) 29 29 39
[0041] Coatings were applied at 75 micron WFT (wet film thickness)
using a Bird applicator resulting dry film thickness was 65 to 70
microns. Films were cured at 5 C and 50% humidity for a period of
24 hours. Films were evaluated for tack and blush on a scale of 0-5
where 0 designates no blush or tack and 5 designates severe blush
or tack. Amine blush was determined using The Elcometer 139 Amine
Blush Kit. Dry times were measured using a BK recorder in
accordance with Test Method ASTM D-1640. Gloss was measured by ASTM
D523. Tg was measured using a DSC in accordance with Test Method
ASTM E-1356.
TABLE-US-00002 TABLE 2 Coatings examples 1 2 3 Properties @ RT Film
appearance on Opaque film due A lot of bubbles Continuous glass
(visual) the many internal encapsulated Film bubbles. The in the
film. film seems Exudation and some retract. little orange peel
Blush after 24 hours 3-4 3-4 0-1 (scale: 0-5) Gloss
20.degree./60.degree. 65/104 34/108 74/105 Tack after 24 hours 5
0-1 0-1 (scale: 0-5) Tg after 9 days 42.38 41.4 44.36 Pot-life 3 h
27 3 h 17 Drying time 16:00 02:50 01:30 (h:min) -- 07:15 03:30 --
09:00 06:00 -- -- --
[0042] A comparative example using ethylenediamine-MIBK and
N,N'-1,2-Etanediylbis(1,3-Propanediamine)-MIBK exhibited a film
with superficial defects that never fully cured with a high degree
of blushing. Benzylated polyamine-MIBK provided a continuous film
that was tack and blush free with a thin film set time of 5
hours.
Example 5
Preparation and Testing of Coatings Produced with Ketimines Using
Alternative Ketones to Replace MIBK
[0043] A curable epoxy resin was prepared by mixing ketimine with
commercially available diglycidyl ether of bisphenol A (epoxy
equivalent weight approx 190 Dow Epoxy Resin DER 331) in
proportions listed in Table 3. A high speed mixer was used for
mixing.
TABLE-US-00003 TABLE 3 Coatings Formulations Methylene- Benzylated
Methylene- biscyclo- Ethylene- polyamine/ Benzylated biscyclo-
hexanamine, diamine/ MEK polyamine/ hexanamine, 4,4'-/CYCLO-
Ethylene- CYCLO- (Inventive CYCLO- Ketimine 4,4'-/MEK HEXANONE
diamine/MEK HEXANONE Ketimine) HEXANONE AHEW 79.50 92.50 42.10
55.10 76.50 85.30 EEW 190 190 190 190 190 190 phr with DER331 41.84
48.68 22.16 29.00 40.26 44.89 or similar (EEW = 190)
[0044] EEW is the Epoxy Equivalent Weight of the Epoxy resin used
(Dow Epoxy Resin DER331 or similar) and AHEW is the Amine Hydrogen
Equivalent Weight.
[0045] The quantity of the Ketimine to react stoichiometric with
100 grams (phr) of the Epoxy Resin (DER331 or similar) mentioned on
Table 3 was calculated by the formula below:
phr = A H E W E E W .times. 100 ; ##EQU00001##
[0046] On the example with Benzylated polyamine/MEK Ketimine (The
Inventive Ketimine) 40,26 grams of the mentioned ketimine was used
to react with 100 grams of Diglycidil Ether of Bisphenol-A with
(DER331 or similar) a Epoxy Equivalent Weight (EEW) of 190.
[0047] Coatings were applied at 75 micron WFT (wet film thickness)
using a Bird applicator resulting dry film thickness was 65 to 70
microns. Films were cured at 5 C and 50% humidity for a period of
24 hours. Films were evaluated for tack and blush on a scale of 0-5
where 0 designates no blush or tack and 5 designates severe blush
or tack. Amine blush was determined using The Elcometer 139 Amine
Blush Kit. Dry times were measured using a BK recorder in
accordance with Test Method ASTM D-1640. Tg was measured using a
DSC in accordance with Test Method ASTM E-1356. The results of the
evaluations are listed in Table 4.
TABLE-US-00004 TABLE 4 Coatings Examples Benzylated Methylene-
Benzylated polyamine/ Methylene- biscyclo- Ethylene- polyamine/
CYCLO- biscyclo- hexanamine, diamine/ MEK HEXANONE hexanamine,
4,4'-/CYCLO- Ethylene- CYCLO- (Inventive (Inventive Ketimine
4,4'-/MEK HEXANONE diamine/MEK HEXANONE Ketimine) Ketimine) Visual
Continuous, Solid at Very Discontinuous Continuous Continuous
Appearance yellow and Ambient discontinuos and and uncured and
cured and cured cured Temperature uncured film. It film. film film
film presented tack even after 7 days Tack after 0 ** 5 2 0 0 24
hours (scale: 0-5) Blush after 0 ** 0 0 0 0 24 hours (scale: 0-5)
Drying Stage 1 05:00 ** -- 07:00 02:45 03:15 time Stage 2 08:15 **
-- -- 03:45 05:15 (h:min) Stage 3 10:00 ** -- -- 05:00 06:45 Stage
4 13:15 ** -- -- 06:00 09:00
[0048] Comparing the data of formulation 1 from Table 2 (Ketimine
formulated with Ethylenediamine and Methyl Isobutyl Ketone) and
Table 4, each of the inventive ketimines formulated with Benzylated
Polyamines provided coating properties with faster drying times and
completely eliminated the presence of amine blush and tack on the
surface of the coating.
Example 6
Preparation and Testing of Coatings Produced by Combining Ketimines
with Other Types of Amine Curing Agents
[0049] A curable epoxy resin was prepared by mixing the inventive
ketimine with commercially available diglycidyl ether of bisphenol
A (epoxy equivalent weight approx 190 Dow Epoxy Resin DER 331) in
proportions listed in Table 5. A high speed mixer was used for
mixing.
TABLE-US-00005 TABLE 5 Coatings Formulations Raw Material 4 5 6
Ethylenediamine/MIBK 49 Cycloaliphatic Amine (Ancamine 2167) 50 50
50 Imicure AMI-1 1 1 1 Benzlated polyamine/MEK 49 Benzylated 49
polyamine/CYCLOHEXANONE AHEW 54.52 63.13 65.88 EEW 190 190 190 Phr
28.69 33.23 34.68
[0050] Coatings were applied at 75 micron WFT (wet film thickness)
using a Bird applicator resulting dry film thickness was 65 to 70
microns. Films were cured at 5 C and 50% humidity for a period of
24 hours. Films were evaluated for tack and blush on a scale of 0-5
where 0 designates no blush or tack and 5 designates severe blush
or tack. Amine blush was determined using The Elcometer 139 Amine
Blush Kit. Dry times were measured using a BK recorder in
accordance with Test Method ASTM D-1640. Tg was measured using a
DSC in accordance with Test Method ASTM E-1356. The results of the
evaluations are listed in Table 6.
TABLE-US-00006 TABLE 6 Coatings Examples Raw Material 4 5 6
Appearance Film with big crakers Continuous Film with (4 mm widht)
Film spots Tack after 24 hours 0-1 0 0 (scale: 0-5) Blush after 24
hours 5 1 0 (scale: 0-5) Drying time -- -- 02:45 (h:min) 00:15
03:00 04:45 -- 07:30 09:00 20:45 -- --
[0051] In the case of coatings formulated with Ketimine in
combination with other amine curing agents, in this case more
specifically with Cycloaliphatic Amine (Ancamine 2167), the
ketimine produced with Benzylated Polyamine and MEK provided a film
having improved properties.
Example 6
Preparation and Testing of Coatings Produced by Combining Ketimines
with Other Types of Amine Curing Agents
[0052] A curable epoxy resin was prepared by mixing ketimine with
commercially available diglycidyl ether of bisphenol A (epoxy
equivalent weight approx 190 Dow Epoxy Resin DER 331) in
proportions listed in Table 7. A high speed mixer was used for
mixing.
TABLE-US-00007 TABLE 7 Coatings Formulations Raw Material 7 8 9 10
Imicure AMI-1 1 1 Benzylated polyamine/MEK 49 49 50 50
Cycloaliphatic Amine Adduct 40 40 (Ancamine 2764)
1,2-Diaminocyclohaxane 10 Trimethyl hexametilene 10 Diamine Mannich
Base (Ancamine 25 2422) Modified Aliphatic Amine 25 (Ancamine 2432)
Benzyl Alcohol 25 25 AHEW 72.67 78.27 85.93 106.65 EEW 190 190 190
190 Phr 38 41 45 56
[0053] Coatings were applied at 75 micron WFT (wet film thickness)
using a Bird applicator resulting dry film thickness was 65 to 70
microns. Films were cured at 5 C and 50% humidity for a period of
24 hours. Films were evaluated for tack and blush on a scale of 0-5
where 0 designates no blush or tack and 5 designates severe blush
or tack. Amine blush was determined using The Elcometer 139 Amine
Blush Kit. Dry times were measured using a BK recorder in
accordance with Test Method ASTM D-1640. The results of the
evaluations are listed in Table 8.
TABLE-US-00008 TABLE 8 Coatings Examples 7 8 9 10 Visual Continuous
Continuous Continuous Continuous Appearance film with film film
film with some blush some blush Tack after 24 0 1 0 0 hours @ RT
(scale: 0-5) Blush after 24 0 0 0 2 hours @RT (scale: 0-5) Tack
after 24 * 5 1 2 hours @ 5 C. (scale: 0-5) Blush after 24 * 0 0 0
hours @5 C. (scale: 0-5) Drying time 02:00 01:30 02:00 03:00
(h:min) 03:15 02:45 03:45 05:15 05:30 03:30 06:45 07:00 * * 10:15
11:00
[0054] In these Examples, the ketimine produced with Benzylated
Polyamines and MEK demonstrates its applicability to obtain films
with good visual appearance, even when the ketimine is combined
with other curing agents. While the invention has been described
with reference to certain aspects or embodiments, it will be
understood by those skilled in the art that various changes may be
made and equivalents may be substituted for elements thereof
without departing from the scope of the invention. In addition,
many modifications may be made to adapt the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *