Note: Descriptions are shown in the official language in which they were submitted.
~22~2
The instant invention pertains to polyfunctional
finlike hydroxyl terminated hardener products and to curable
solid epoxy resin compositions containing said hardeners.
.
The reaction of epoxy resins with finlike hydroxy-
containing compounds in the presence of a catalyst is well
known in the art. This reaction is typified by the reaction of
bisphenol A (- BRA or I isopropylidenediphenol) with liquid
BRA epoxy resins to form solid high molecular weight products.
U.S. Patent No. 3,931,109 teaches the termination of
basic liquid BRA epoxy resins as well as epoxy novolac resins
with bisphenol A to give finlike hydroxyl terminated
hardeners.
U.S. Patent No. 3,931,109 also teaches curable
compositions of liquid epoxy resins containing a dispersion of
a solid finlike hydroxyl terminated hardener therein.
The instant polyfunctional finlike hydroxyl terminated
hardener products are superior to the hardeners described in
U.S. 3,931,109 in respect to curing solid epoxy resins to cured
products with outstanding properties particularly in regards to
-- 2 --
I
chemical resistance. This is especially of value in the field
of coatings.
The products of this invention are useful as curing
agents for epoxy resins. When these items are combined with
dip and polyepoxide resins and cured at elevated temperatures
(e.g. 180C) a dense cross linked network is established which
produces superior protective coatings. These coatings, when
applied by electrostatic techniques and properly cured to
produce thin films, excel in chemical resistance while
maintaining flexibility.
The reason these multi functional hardeners produce their
extremely good chemical resistance is through formation of a
dense cross linked reticulum in the final cured coating. The
difunctional BRA terminate hardeners form linear extensions,
while the multi functional BRA terminated curing agents produce
a web-like structure. This three dimensional network provides
the tight barrier by which the cured final coating strongly
resists any chemical attack.
The reaction of hydroxyl groups with liquid epoxy resins
to form higher molecular weight epoxy resins is described by
H. Lee and I. Seville, "Handbook of epoxy resins", ~IcGr~w Lyle,
1967, Jew York, pp. I , 2-9. Chapter 2 of Lee and evils
Ilk
"Handbook of Epoxy Resins" is devoted to the "Synthesis of
Glycidyl-Type Epoxy Resins". This chapter describes the
synthesis of high molecular weight epoxy resins based on many
types of alcohols.
U.S. Patent No. 4,322,456 discloses powder coating
compositions consisting of an epoxy resin, a finlike hardener
and a catalyst for effecting reaction between said resin and
said hardener.
The instant polyfunctional finlike hydroxyl terminated
hardener products are superior to the hardeners described in
U.S. 4,322,456 in respect to curing solid epoxy resins to cured
products with outstanding properties particularly in respect to
chemical resistance while maintaining flexibility.
U.S. Patent No. ~,288,565 pertains to epoxy molding
compositions wherein triphenols such as l,1,3-tris(4-hydroxy-
phenyl)propane are used as the finlike hardener component.
While both the instant hardeners and those of this reference
have three or more finlike groups per molecule, the remainder
of the respective hardener molecules differ widely. The prior
art hardener is a relatively small molecule with the terminal
finlike hydroxy groups attached to the backbone trim ethylene-
(propane) chain at very close intervals. While this does not
-- 4 --
7~2
interfere with the hardening efficacy of the molecule, the cured epoxy resin is a relatively rigid and inflexible
structure due to the high cross link density (nearness together
of the original finlike hydroxyl groups).
By contrast the instant hardeners, wherein the terminal
finlike hydroxyl groups are relatively far removed from one
another with a relatively bully linking group there between,
permit good curing since the efficacy of the finlike hydroxyl
groups is undiminished. However, a lower cross link density is
obtained leading to a concomitant increase in flexibility with-
out loss of chemical resistance.
The preponderance of hy2roxyl groups present in the
instant hardeners also allows for improved adhesion of epoxy
resin cured thereby.
One object of the instant invention is a polyfunctional
finlike hydroxyl terminated product useful as hardener in the
curing of solid epoxy resins.
A second object of the instant invention is a curable
composition comprising a solid epoxy resin and a polyfunctional
~henolic hydroxyl terminated hardener of this invention.
~77~
Still another object of this invention is a cured
composition having superior properties prepared by curing a
composition comprising a solid epoxy resin and a polyfunctional
finlike hydroxyl terminated hardener of this invention.
The instant invention pertains to a polyfunctional
finlike hydroxyl terminated hardener product useful in the
curing of epoxy resins, which is the reaction product of
a) a polyglycidyl compound of the formula I, II, III or
IV
Tl~-N(glycidyl)2]2 (I),
,,M(glycidyl)2
To (II),
O-glycidyl
T3(-0-glycidyl)3 or 4 (III) or
T4~glycidyl)3 (IVY
7Z~
wherein
To is 1,2-phenylene, 1,3-phenylene, 1,4-phenylene or
Q
where Q it alkaline of 1 to 6 carbon atoms, alkylidene of 2 to
6 carbon atoms, -S2 , -SO-, -S-, -S-S-, -O- or -CO-,
To is 1,2-phenylene, 1,3-phenylene or 1,4-phenylene,
To is 1,2,3-benzenetriyl, 1,2,4-benzenetriyl,
1,3,5-benzenetriyl or ( )2CHCH( I
I
To is ON\
f 1 or
Jo N-
KIWI/
Go Go
G2~CO KEG
-N N-CH2CHCH2-N N-
\/ I \ /
CO O I
where Go and Go are independently alkyd of 1 to 6 carbon atoms
or are together alkaline of 4 to 5 carbon atoms, and
b) a diglycidyl compound of the formula
glycidyl~O-E-O-glycidyl
where
E is 1,2-phenylene, 1,3-phenylene, 1,4-phenylene or
. L
where L is a direct bond, alkaline of 1 to 6 carbon atoms or
alkylidene of 2 to 6 carbon atoms,
wherein the ratio of equivalents of polyglycidyl
compound (a to diglycidyl compound (b) is from 1 to 4 to 1 to
1, with
(c) a bisphenol of the formula
HO-El-OH
where El has the same definitions as E, but is independent of
E,
wherein the ratio of equivalents ox bisphenol component (c) to
the total equivalents of glycidyl compounds (a) plus (b) is
from 1.8 to 1 to 2.4 to 1, and where each glycidyl group is
effectively end capped with a moiety containing a foe finlike
hydroxyl group by reaction of components (a) and (b) with (c)
in the presence of an effective amount of a catalyst for
promoting said reaction at a temperature between 120 and
300C.
Another aspect of the instant invention relates to
curable compositions comprising
(A) a solid epoxy resin ha no more than one 1,2-epoxy
group,
Lo 2
(B) a polyfunctional finlike hydroxyl terminated epoxy
hardener product of the instant invention or mixtures thereof,
and
(C) a catalytic amount of a catalyst effective in
causing reaction between the epoxy groups of (A) and the
finlike hydroxyl groups of (B),
wherein the epoxy resin (A) and the hydroxyl terminated
hardener (B) are employed in the range of 1:0.4 to 1:1.2;
preferably of 1:0.5 to 1:0.8; and most preferably of 1:0.65
to 1:0.75.
A further aspect of the instant invention pertains to
cured epoxy resin compositions prepared from the curable
compositions of the instant invention. Such cured compositions
find utility in a host of end-use applications including
moldings and electrical uses, but it is particularly in the
field of coatings that the instant cured compositions find
their most important use. the properties of such cured
coatings are excellent, especially in rewards to chemical
resistance, flexibility and adhesion.
The polyfunctional finlike hydroxyl terminated
hardeners of the instant invention are prepared by reaction of
a polyglycidylated aromatic Damon, amino phenol, polyphenol
with functionality more than 2 or heterocyclic nitrogen
compound and a diglycidyl ether of a bisphenol with a bisphenol
_ g _
.
l:~Z720Z
in such amounts that about two equivalents of bisphenol are
reacted with each equivalent of glycidyl moiety loading to the
instant compounds containing finlike end groups on each
original glycidyl moiety
These polyglycidylated compounds (a) are in many cases
items of Connors or may be prepared in a conventional
glycidyla-tion reaction with epichlorohydrin and the
commercially available aromatic dominoes, amino phenols,
polyphenols or heterocyclic nitrogen compounds.
To is derived prom aromatic dominoes such as o-, m- or
p-phenylenediamine or the dominoes of the formula
NH Q NH2 where Q is alkaline of 1 to 6 carbon atoms,
alkylidene of 1 to 6 carbon atoms, -S02-, -SO-, -S-, -S-S-, -O-
or -CO-.
Preferably To is 1,3-phenylene, 1,4-phenylene or
Q where Q is ethylene or -O-. Most preferably T
is I where Q is ethylene.
To is derived from o-, m- and p-aminophenols.
Preferably To is 1,4-phenylene.
-- 10 --
72~2
To is derived from polyfunctional phenols having a
functionality of 3 or 4. These polyphenols include
phloroglucinol, pyrogallol, 1,2,4-benzenetriol and
1,1,2,2-tetrakis(4-hydroxyphenyl)ethane.
Preferably To is ( )2CHCH( I
To is derived from nitrogen heterocyclic compounds
including triglycidyl isocyanurate or triglycidyl
bis-hydantoins of the formula
Go Go
G2.~--fo f (32
glycidyl-N /-CH21CHCH2-N 7--glycidyl
CO O CO
glycidyl
where Go and Go are independently alkyd of 1 to 6 carbon atoms,
- preferably methyl, or Go and Go are together alkaline of 4 to 5
carbon atoms.
Preferably To is derived from triglycidyl isocyanurate.
The diglycidylated derivatives of bisphenols are also
items of commerce or may be prepared by the conventional
glycidylation reaction with epichlorohydrin and commercially
available bisphenols.
The diglycidylated compounds (b) have the formula
glycidyl-O-E-O-glycidyl and are derived, for example, from
catcall, resorcinol, hydroquinone, o,o'-biphenol, pup'-
biphenol, bist2-hydroxyphenyl)methane, bis~4-hydroxyphenyl~-
methane and 2,2-bis(4-hydroxyphenyl)propane. E is thus 1,2-
phenylene, 1,3-phenylene, 1,4-phenylen0 or - L-
where L is a direct bond, al}~ylene of l to 6 carbon atoms or
alkylidene of 2 to 6 carbon atoms.
Preferably E is L where L is isopropylidene.
The bisphenols (c) have the formula
HO-El-OH
where El has the same definitions as E given above, but E and
El are independent or one another. Examples of suitable
bisphenols are delineated swooper.
The reaction of the polyglycidylated and diglycidylated
compounds with the bisphenol to make the instant polyfunctional
finlike hydroxyl terminated hardener is carried out in the
- 12 -
~:;272~Z
presence of a catalytic amount of a catalyst effecting the
reaction between an epoxy or glycidyl group and a finlike
hydroxyl group.
Suitable catalysts which are employed to effect the
reaction between the glycidyl group and the finlike hydroxyl
groups include the phosphonium salts of organic and inorganic
acids, imidazoles, imidazolines, qua ternary ammonium compounds
and the live. Any catalyst which will effectively promote the
reaction between a 1,2-epoxide group and a finlike hydroxyl
group can suitably be employed in the present invention.
The catalysts are generally employed in quantities of
from about 0.001% to about 10~ and preferably from about 0.05%
to about 5% by weight based upon the combined weight of the
reactants, i.e. the weight of glycidyl-cGntaining compound plus
the weight of the finlike hydroxyl-containing compound.
The inorganic and organic phosphonium compounds which
are employed in the process of the present invention, as
catalysts, include phosphonium salts of an acid, acid ester
or ester of an element selected from the group consisting of
carbon, nitrogen, phosphorus, sulfur, silicon, chlorine,
bromide, iodine and boron which are represented by the general
formula:
~l2;~7~
Al
R4- P R2 em
I m
wherein Al, R2, R3 and R4 are independently selected from the
group consisting of hydrogen, aliphatic hydrocarbon radicals
containing from about 1 to 20 carbon atoms, aromatic
hydrocarbon radicals, alkyd substituted aromatic hydrocarbon
radicals and radicals represented by the formula Rosy
wherein Us is an aliphatic hydrocarbon radical having from
about 1 to about 20 carbon atoms and Y is a member selected
from the group consisting of Of, Bra I, NO, H and OH and where
X is the union portion of an acid, ester or acid ester of an
element selected from carbon, nitrogen, phosphorus, sulfur,
silicon, chlorine, bromide, iodine and boron and wherein m is
the valence of the anion X.
;, .
` Particularly suitable catalysts include ethyltriphenyl
phosphonium iodide, ethyltriphenyl phosphonium chloride,
ethyltriphenyl phosphonium thiocyanate, ethyltriphenyl
phosphonium acetate acetic acid complex, tetrabutyl phosphonium
iodide, tetrabutyl phosphonium bromide, and tetra~utyl
phosphonium acetate acetic acid complex.
. '
I
These and other phosphonium catalysts are more fully
described in U.S. Patent No. 3,477,990 and U.S. Patent No.
3,341,580.
Suitable imidazoles which may be employed as catalysts
in the present invention include, for example,
2-styrylimidazole, 1-benzyl-2-methylimidazole,
2-methylimidazole, 2-butylimidazole, mixture thereof and the
like. These and other suitable catalysts are disclosed in Lee
and Seville, "Handbook of Epoxy Resins", McGraw Hill, 1967, New
York, pp. 11-14.
The imidazole catalysts are particularly preferred in
the preparation of the instant hardeners.
It is noted that the catalysts described above which are
useful in -the preparation of the instant hardeners are the very
same catalysts which may be used as component (C) in the
curable compositions of the instant invention.
These curable compositions comprise
(A) a solid epoxy resin hazing more than one 1,2-epoxy group,
(B) a polyfunctional finlike hydroxyl terminated epoxy
hardener of this invention, and
~2~Z~7;~0~
(C) a catalytic amount of a catalyst effective in causing
reaction between the epoxy groups of (A) and the finlike
hydroxyl groups of (B).
Suitable solid epoxy resins which are employed as
component (A) in the present invention include the aromatic
based epoxy resins represented by the following general
formulae including mixtures thereof.
CH2-CH-CH2-0-~A~0-~ -CH-CH2-O,~_A_~ CH2-CH-cH2
X X OH X n
wherein A is a diva lent hydrocarbon group having from about 1
to about 6 carbon atoms,
O O O
. . I I' 11 .
-C-, -O-, -S-, -S-S-, -S- or -S-,
each X is independently hydrogen, chlorine or bromide, and n
has an average value of from about 1 to about 12 and preferably
from about 3 to about 7.
- I
~22~0~
- o-cH2-c~l2 o-cH2-cH-\H2 o- cH2-cH-~k2
- OH- R X
wherein R is hydrogen or an alkyd group having from about 1 to
about 4 carbon atoms, n has an average value of from about O to
about 8, and X is hydrogen, chlorine, bromide or a lower alXyl
group having from 1 to about 4 carbon atoms.
The epoxy resins employed in the present invention may
be prepared by any of the well known methods such as the
reaction of a bisphenolic compound with an epi.halohydrin in the
presence of suitable catalysts or by the reaction of a liquid
polyepoxide with a bisphenol in the presence of such compounds
as qua ternary ammonium compounds, tertiary amine, phosphonium
compounds and the like. These methods are discussed in Chapter
2 of Handbook of Epoxy Resins by Lee and Seville, McGraw Hill
Book Co., 1967 and in U.S. Patent Jo. 3,477,990.
Any solid aromatic based epoxy resin which has more than
one 1,2-epoxy group is suitable for use in the present
invention.
I
Suitable hardeners which may be used as component (B) in
the instant invention are the polyfunctional finlike hydroxyl
terminated hardeners described above and being the reaction
product of a polyglycidyl compound of formula I, II, III or IV,
a diglycidyla-ted compound of formula glycidyl-O-E-O-glycidyl,
end a bisphenol of formula HO-El-OH.
Preferably, component (B) is a hardener derived from a
polyglycidyl compound of formula I, II or III where To is
- - SHEA - -, To is 1,4-phenylene, To is
(- -)2CHCH(- -)~, from a diglycidyl compound and from a
bisphenol where and El are respectively both
_ -C(CH3)2- -
Those skilled in the ark will readily recognize thrush of epoxy compound to finlike 'nydroxyl-containing
compound required to produce a product of desired molecular
weight or simple experimentation can be employed to arrive at
the desirable ratio for any desired molecular weight.
The instant curable compositions may find utility in a
host of end-use applications including moldings and electrical
uses. However, it is in the field of powder coatings that
these curable compositions find their most advantageous use.
- 18 -
~;227~
The instant curable compositions may contain, if
desired, dyes, pigments, flow aids and other suitable
additives. The compositions in powder form may be used to coat
suitable substrates by depositing said powder on the substrate
followed by subsequent heating of the powder coated substrate
to effect the catalyzed curing reaction between the solid epoxy
resin, component (A), and the poly~unctional finlike hydroxyl
terminated hardener, component (B), in the presence of the
catalyst, component I
The curing reaction is effected by heating the coated
substrate to effect the reaction between (A) and (By usually
between about 120 to about 300C and preferably from about
140C to about 300C for from about 10 seconds to about 60
minutes and preferably from about 10 seconds to about 30
minutes or applying said composition to a substrate preheated
to a temperature of from about 120 to about 300C, preferably
from about 140C to about 300C, the cure thereby being
obtained by the transfer of heat from the heated substrate to
the coating.
The substrates which are employed in the process of the
present invention are metallic substrates such as steel,
aluminum, etc. but any substrate which Will withstand
temperatures of at least about 130nC can be employed.
- 19 -
~227%~
Pigments, fillers, dyes, flow control agents and other
modifier compounds may also be employed in the coating
compositions employed in the coating process or method of the
present invention.
In the present invention, the coated substrates are
subjected to temperatures which will effect the reaction
between the epoxy resin and the finlike hydroxyl containing
compound. The time employed is of course, dependent upon the
temperature, the mass of the coated substrate, etc. For
example, thin metallic substrates subjected to a temperature of
3007C would require only a few seconds to effect and complete
the reaction whereas automobile bodies subjected to a
temperature of 120C would require upwards to 60 minutes to
effect and complete the reaction between tune epoxy resin and
the finlike hydroxyl-containing compound.
The coatings of the present invention can be employed as-
coatings for such articles as automobiles, machinery,
appliances, containers and the like.
The following examples are presented for the purpose of
illustration only and are not to be construed to limit the
nature or scope of the instant invention in any manner
whatsoever.
-- I --
.
~2~72~
PREPARATION OF THE HYDROXYL TERMINATED CURING AGENTS
Example 1
A three-necked round-bottomed flask equipped with a
heating mantle, mechanical stirrer, thermometer, and nitrogen
inlet tube is charged with 66.5 g (0.627 en.) of N,N,0-tri-
glycidyl-p-aminophenol, 141.25 g (0.743 en.) of
2,2-bis(4-glycidyloxyphenyl)propane (or the diglycidyl ether of
bisphenol A, equivalent weight is 190), 285 g (2.5 en.) of
bisphenol A, and 40 ppm of 2-isopropylimidazole.
The flask and contents are heated to 100C and held at
that temperature for one hour, after which the temperature is
increased to 125C and held for another hour. The 25C
increments with a subsequent hold at temperature for one hour
are continued until the reaction temperature of 175C is
reached. The flask and contents are held at 175C for two
hours. The flask is discharged after two hours and the
reaction product is cooled to room temperature. The hydroxyl
terminated product is then characterized by a Gardner-Holdt
viscosity at 25C of U-V (ASTM D-445), a molting point of
102-103C, and a theoretical combining weight of 444 g.
This product is designated AA.
- 21 -
Example 2
Using the general procedure of Example 1, 162.1 (1.29
en.) ofN,N,N',N'-tetraglycidyl-4,4-diaminodiphenylmethanee,
293.6 g (1.54 eke of 2,2-bis(4-glycidyloxyphenyl)propane,
768.6 g (6.74 en.) of bisphenol A, and 40 ppm of
2-isopropylimidazole are reacted. The addition product is
characterized by viscosity at 200C of 0,72 Pays, a melting
point of 90C, and a theoretical combining weight of 308 g.
This product is designated BY.
Example 3
Using the general procedure of Example 1, 112.2 g. (0.60
en.) of 1,1,2,2-tetrakis(p glycidyloxyphenyl)ethane, 152.0 g
(0.80 en.) of 2,2-bis(4-glycidyloxyphenyl)propane, 364.8 g
(3.2 en.) of bisphenol A, and 40 ppm of 2-isopropylimidazole
are reacted. The addition product is characterized by an
viscosity at Coffey pus, ameltingpointof likened a
theoretical combining weight of 349 g.
This addition product is designated CC.
I
Example 4
Using the general procedure of Example l, 122 g (l en.)
of crossly novolac resin hardener having the structure
SHEA OH -
where n is 3.1, 228 g (2 en.) of bisphenol A, 188 g (l en.)
of 2,2-bis(4-glycidyloxyphenyl)propane, and 40 ppm of issue-
propylimidazole are reacted. The addition product is kirk-
towered by a Gardner-Holdt viscosity at 25C of U, a melting
point of 95-96C and a theoretical combining weight of 269 g.
This addition product is designated DUD.
PREPARATION OF CURED EPOXY RESINS
USING THE HYDROXYL TERMINATED CURING AGENTS
.
Example 5
Thy product AA, prepared in Example 1, is used as 2
multi functional hydroxy terminated curing agent in an epoxy
resin formulation as is seen below.
.
Component Material g
1,1,2,2-tetrakis(p-glycidyloxypnenyl)etnane OWE
PA 88.2
Flow Aid t"MODAFLOW", Monsanto)* 2.25
2-methylimidazole 0.3
Red Iron Oxide 15.0
- 23 -
I 2
* "MODAFLOW" flow control agent or flow aid is a poly~2-ethyl-
Huxley acrylate) sold by Monsanto.
This formulation is 2-roll milled at 70C for 6 minutes. The
melt mixed formulation is then cooled, ground, sieved through a
140 mesh screen (105 microns maximum size), and applied by
electrostatic techniques to cold rolled steel panels. These
coated test panels are then tested for their physical
characteristics as is seen in Example 14.
This formulation is designated HE.
Example 6
As a control, a difunctional hydroxy terminated curing
event, similar to those described in U.S. 3,931,109, is used as
a curing agent in an epoxy resin formulation. The difunctional
curing agent is prepared by the reaction of two equivalents of
bisphenol A with one equivalent of Boyce-
glycidvloxyphenyl)propane and is designated DFCA.
The epoxy resin control formulation is as phase.
- I -
Component Material g
1,1,2,2-tetrakis(p-gl~cidyloxyphenyl)ethane 78.75
DFCA 55.18
Flow Aid 1.125
Red Iron Oxide 15.0
This formulation is processed and applied as in Example 5. The
resulting coated panels are then used for testing of physical
characteristics as seen in Examples 14 and 18.
This formulation is designated OF.
Example 7
Product AA, prepared in Example 1, is formulated with
a commercially available solid bisphenol A-based epoxy resin
having an epoxy content of 1,38-1,48 equivalents/kg. The
formulation is as follows:
Component Material g_
Solid bisphenol A-based
epoxy resin 50.5
AA 27.5
Flow Avid ("MODAFLOW")1.5
2-methylimidazole 0.5
Red Iron Oxide 15.0
The formulation is processed and applied as in Example 5 and
the resulting coated panels are jested for physical
characteristics as seen in Example 16.
This formulation is designated GO.
- 25 -
I
Example 8
Product DFCA, described in Example 6, is formulated with
the solid bisphenol A-based epoxy resin used in Example 7.
The formulation is as follows:
Component Material ` g
Solid bisphenol A-based epoxy resin 57.4
DFCA 21.1
Flow Aid ("MODAFLOW") 1.5
Red Iron Oxide 15.0
The formulation is processed and applied as in Example 5 and
the resulting coated panels are tested for physical
characteristics as seen in Examples 16, 17 and 19.
This formulation is designated HUH.
Example 9
Product BY, prepared in Example 2, is formulated in
combination with the solid bisphenol A-based epoxy resin
used in Example 7. The formulation is as follows:
- 26 -
I
Component Material
Solid bisphenol A-based epoxy resin 90.8
BY 41.7
Flow Aid ~"MODAFLOW") 2.25
2-methylimidazole 0.3
Red Iron Oxide 15.0
The formulation is processed and applied as in Example 5 and
the resulting coated panels are tested for physical
characteristics as seen in Examples 17.
This formulation is designated Rio
Example 10
Product CC, prepared in Example 3, is formulated in
combination with commercially available solid epoxy resin
1,1,2 2-tetrakis(p-glycidyloxyphenyl)ethane. The formulation
is as follows:
Component Material __~__
1,1,2,2-tetrakis(p-glycidyloxyphenyl)e'hane 46.2
CC 86.25
Flow Aid ("MODAFLOW") 2.25
2-methylimidazole 0-3
Red Iron Oxide 15.0
- 27 -
~27;~
The formulatiora is processed and applied as in example 5 and
the resulting coated panels are tested for physical
characteristics as seen in Examples 18.
This formulation is designated JO
Example 11
Product DUD, prepared in Example 4, is formulated in
combination with the solid bi.sphenol A-based epoxy resin
used in Example 7. The formulation is as follows:
Component Material g
Solidbisphenol Abased epoxy resin 100.0
DUD 39.0
Flow Aid ("MODAFLOW") 2.5
2-methylimidazole 0.3
Shea 28.0
The formulation is processed an applied as in Example 5 and
the resulting coated panels are tested for physical
characteristics as seen in Example 19.
This formulation is designated I.
- 28 -
I
Example 12
Product AA, prepared in Example 1, is formulated in
combination with 1,1,2,2-tetrakis(p-glycidyloxyphenyl)ethane
and the solid bisphenol A-based epoxy resin used in
Example 7. The formulation is as follows:
Component Material g
Solid his phenol A-based epoxy resin 26.5
1,1,2,2-tetrakis(p-glycidyloxyphenyl)ethane 53.25
AA 56.6
Flow Aid ("MODAFLOW") 2.25
2-methylimidazole 0.3
Red Iron Oxide 15.0
The formulation is processed and applied US in Example 5 and
the resulting coated panels are tested for physical
characteristics as seen in Example 15.
This formulation is designated LO.
Example 13
A formulation based on the difuncticnal DFCA curing
agent, described in Example 6, is formulated with
1,1,2,2-tetrakis(p-glycid~floxypherlyl)ethane and solid bisphenol
A-based epoxy resin used in Example 7. The formulation is
as follows:
- I -
onent Material _ g
Solid bisphenol A-based epoxy resin 21.75
1,1,2,2-tetrakis(p-glycidylo~yphenyl)ethane 43.5
DFCA 57.2
Flow rid ("MODAFLOW") 2.25
Red Iron Oxide 15.0
This formulation is processed and applied as in Example 5 and
the resulting coated panels are tested or physical
characteristics as seen in Example 15. .
This formulation is designated MM.
TESTING OF EPOXY RESINS CURED WITH
HYDROXYL TERMINATED CURING AGENTS
Chemical resistance testing is conducted at button room
temperature (23C) and at elevated temperatures (refluxing
temperatures for various solvents). Sand blasted cold rolled
steel panels and 1.27 cm round stock are the substrates for the
testing. The films range in thickness from 3 to 4 miss (0.076
to 0.102 mm) on the panels and 12 to 16 miss (0.305 to 0.~06
mm) on the rods. The substrates are powder coated by
electrostatic spray techniques at room temperature for the
thinner films and at 200C for the thicker films.
- I -
:
I
In order to demonstrate the superiority of the products
of this invention, aggressive solvents and elevated
temperatures ore used. Some or all ox the hollowing solvents
are employed to demonstrate the utility of the invention:
Acetic acid (10~)
Methyl ethyl kitten (ME)
Ethanol
Ethylene chloride
Acetone
Refluxing 10% sulfuric acid
Refluxing sodium hydroxide solution (pi = 13.5)
Boiling water
Refluxing ME
.
Failures are evidenced by blister formation, delamination,
softening to substrate, or total destruction of the coating.
Example 14
PHYSICAL TEST RESULTS
Formulation HE OF (control)
Contains AA DFCA
Gel @ 171C 44 sec. 85 sec.
Cure Schedule 30 min. @ 200C 30 min. 200C
Appearance Smooth Smooth
Thickness 3.3 to 3.5 miss 3.0 to 3.2 miss
(0.084 to 0.089mm) (0.076 to 0.081mm)
Closed Direct Impact >160 inch-lbs. >160 inch-lbs.
(>1.76 Kg m) (>1.76 Kg m)
Mandrel Bend Pass 1/2 inch Pass 1/8 inch
(1~.7mm) (3.2mm)
I
CHEMICAL TEST RESULTS
Thickness 3.0 to 3.3 miss (0.076 to 0.084 mm)
Acetic Acid two%) > 35 days > 35 days
Methyl Ethyl Kitten > 35 days < 1 day
Ethanol > 35 days < 1 day
Ethylene Chloride > 35 days < 1 day
Acetone > 35 days < 1 day
Refluxing (ME) 24 days < 5 minutes
Example 15
PHYSICAL TEST RESULTS
Formulation LO MM (control)
Contains AA DFCA
Gel @ 171C 49 sec. 86 sec.
Cure Schedule 30 mix Q 200 C 30 min. @ 200~C
Appearance Smooth Smooth
Thickness 3 miss 3 miss
(00076mm) ~0.076mm)
Closed Direct Impact >160 inch-lbs. >160 inch-lbs.
(>1.76 Kg my (>1.76 Kg m)
Mandrel Bend Pass 1/8 inch Pass 1/8 inch
(3.2mm) (3.2mm)
CHEMICAL TEST RESULTS
Thickness 12-16 miss (0.305 to 0.406 mm)
Boiling H20 - >90 days 16 days
Refluxing ~2S04 (10~) ~90 days 42 days
Refluxing Noah (pal = 13.5) >14 days 5 days
- 32 -
.~.
E mule 16
PHYSICAL AND CHEMICAL TEST RESULTS
Formulation GO HUH control)
Contains AA DFCA
Cure Schedule 30 min. @ 200C 30 min. @ 200C
Appearance Smooth Smooth
Thickness 2.0-2.2 miss 2.0-2.5 miss
(0.0508-0.056mm) (0.0508-0.0635mm)
Open Reverse Impact >160 inch-lbs. >160 inch-lbs.
~>1.76 Kg my ~>1.76 Kg m)
Mandrel Bend Pass 1/8 inch Pass 1/8 inch
(3.2mm) (3.2mm)
Methyl Ethyl Rezone 5 min. 5 min.
Refluxing H2SO4 (10%) 76 hours 30 min.
Example 17
PHYSICAL AND CHEMICAL TEST RESULTS
Formulation II HUH (control)
Contains BY DFCA
Cure Schedule 30 min. @ 200C 30 min. 200C
Appearance Smooth Smooth
Thickness 3.0 miss 2.0-2.5 miss
~0.076mm~ ~0.0508 to 0.0535mm)
Open Reverse Impact >160 inch-lbs. >160 inch-lbs.
(>1.76 Kg m) (>1.76 Kg m)
Mandrel Bend Pass 1/8 inch Pass 1/8 inch
(3,2mm) (3.2mm)
Methyl Ethyl Kitten 6 hours 5 min.
Refluxing H~SC4 (lo%) 174 hours 30 mint
I 2
Example 18
PHYSICAL AND CHEMICAL TEST RESULTS
Formulation JO OF (control)
Contains CC DFCA
Cure Schedule 30 min. @ 200C 30 min. @ 200C
Appearance Smooth Smooth
Thickness 3.2-3.5 miss 3.0-3.2 miss
(0.081-0.089mm) (0.076-0.081mm)
Closed Direct Impact >160 inch-lbs. >160 inch-lbs.
(~1.76 Kg my ~>1.76 Kg m)
Mandrel wend Pass 1/8 inch Pass 1/8 inch
(3.2mm) (3.2mm)
Methyl Ethyl Kitten ~14 days I min.
Example 19
PHYSICAL AND CHEMICAL TEST RESULTS
Formulation OK HUH (control)
Contains DUD DFCA
Cure Schedule 30 min. @ 200C 30 min. @ 200C
Appearance smooth Smooth
Thickness 2.2 miss 2.0-2.5 miss
(0.056mm~ Tom)
Closed Direct Impact >160 inch-lbs. >160 inch-lbs.
(>1.76 Kg my (>1.76 Kg m)
Methyl Ethyl Kitten 1 day 5 mint
- 34 -
Example 20
In order to ascertain the influence of stoichiometry on
curing epoxy resins with the hydroxyl terminated hardeners of
this invention and with the objective of delineating the area
where flexibility and chemical resistance of the cured products
would be maximized, a series of runs are carried out using the .
hardener product AA prepared in Example 1 with the epoxy resin
formulations similar to LO described in Example 12 with the
equivalent ratio of epoxy groups of the epoxy resin to the
finlike hydroxyl groups of the hardener ranging from 1:0.4 to
1:1.2. The results of these runs are seen in the table below
where the physical properties of the films prepared from the
cured compositions are delineated
These results show that physical properties of the cured
products rewaken a maximum in terms of impact strength
(toughness) and flexibility when the ratio of equivalents of
epoxy to hydroxyl is in the region of lo to 1:0.~ and
particularly at about 1:0.65 to 1:0.75.
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-- 36 --
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Example 21
The effect of using an instant multi functional hydroxy
terminated curing agent, with relatively large distances
between finlike hydroxyl moieties, in contrast to a multi-
functional hydroxy terminated curing agent of the prior art,
with relatively short distances between finlike hydroxyl
moieties therein, on the physical properties, such as adhesion,
flexibility and chemical resistance, of an epoxy resin
formulation cured thereby is seen by inspection of the data
given below.
An epoxy resin formulation based on 1,1,2,~-tetrakis-
(p-glycidyloxyphenyl)ethane is cured using either the instant
hardener of Example 1 (the product AA) or the prior art harden-
or having the structure
OH OH OH
SHEA SHEA - SHEA
where n is 2 to 4, designated as hardener HUT
The respective formulations are designated (A) and (B)
as given below. Each formulation has one equivalent ox epoxy
I 2
to one equivalent of epoxy to one equivalent of finlike
hydroxyl.
Formulation A
Weight Grams
1,1,2,2-tetrakis-(p-glycidyl-
oxyphenyl)ethane 44.1
Product AA OWE
Flow Aid ("MODAFLO~J") 2.25
2-methylimidazole 0.3
Red Iron Oxide 15.0
Formulation
1,1,2,2-tetrakis-(p-glycidyl-
oxyphenyl)ethane 87.75
Product IT 44.7
Flow Aid ("MODAFLOW") 2.25
2-methylimidazole 0.3
Red Iron Oxide 15.0
These two formulations are then processed and applied as
seen in Example 5 and the resulting coated panels are tested
for chemical resistance as seen in Example 14 and for physical
characteristics as seen in Example 15.
.
These test data are given in the following table.
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-- 39 --
I 2
Inspection of the data given on the table shows that the
prior art hardener (Formulation B) gives a cured epoxy resin
product having appreciably less flexibility, impact resistance
and adhesion than the instant hardener (Formulation A).
Chemical or solvent resistance is comparable.
These data show that the instant hardeners provide
improved physical properties while maintaining goon chemical
resistance.
- 40 -
