Note: Descriptions are shown in the official language in which they were submitted.
~ i~83746
` The invention rclates to new and useful compounds suit-
able ~or hardenlng epo~y -esins having at lea8t one lJ2-epo~ide
group.
~ ovel hardening agents are set rorth that are capable o~
hardening epo~y resins at or below room temperatures ~a8 low as
about 5C without having to supply an e~ternsl source Or heat to
efr~ct the hardening o~ the resin.
Thi3 invention also relates to compositions and methods
o~ using s~id.composition~ and hardening agents to form a resin-
ous costing on a ~ubstrate that will protect the ssme against ~:
the deleterious action o~ 8 wide variety o~ materials including
~et ~uels, kerosene, heating oil~, ~cidsJ solvent8, etc. The
methods and compositions disclosed are particularly useful for
coating ~et ~uel tanks, heating oil tanks and othar containers
Or highly fiammable-liqu~ds, due to the absence of volatile
solvonts in the coating compositions.
The novel co~pounds use~ul ror hardening epo~y resins
ha~ing at least one 1,2-epo~ide group~ng are tho~e compounds o~
the ~ormula:
. _ - _
~ C~3 ~ L 2 - ~ C~3 ~ ~ _H
NCH2 H3 - H2 ~ H2C ~3
wherein n ha3 a value of at least 2.
The compounds have a value wherein n i9 at lea~t 2,
and pre~erably fro~ 2 to 5. Best re~ulfs sre generall~ achicved
when n is 2.
The novel co~pounds Or thi~ invention are userul ~or the
harden~.ng o~ epo~y resi.n~ or pol~epo~ide~ which comprise those
oreanic materials po9sessing at lea3t one vic-epoxy group, i.e.,
...
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, ~:
~ : \c/ \c~ '
The compound~ ma~ be saturated or unsaturated aliphatic
cycloaliphatic, arom~tic or heterocyclic and msy contain
substituents such as halogen atoms, hydroxyl groups, ether
radicals, and the like. They may be ~onomeric or poly~eric.
Generally, such epo~ide re~ins compri~e a polyether deri-
vative Or a polyhydric or~affic compound, said derivative con-
ta~n~ng 1,2-epoxy groups and said compound being selected
~ro~ the group con~ting of polyhydric alcohol~ and phenols
¢ont~ining at least two phenolic hydroxy groups.
¦ A~ong the polyhydr~c phenols which may be used in pre-
I par1ng such glycidyl polyethers are the mono-nuclear phenols
¦ such as resorcinol, catechol, hydroguinone, etc., and the polynuclear phenols such a~ bis(4-hydro~yphenyl~-2,2-propane,
4,4~ -dihydroxybenzephenone, bis(4-hydro~yphenyl)-1,1-ethane,
bis(4-hydro~yphenyl)~ isobutane, bls(l~-hydro~yphenyl~-
2,2-bubane, bist4-hydroxy-2-methylphenyl)-2,2-propane,
bis(4-hydro~y-2-tertiary butylphenyl)-2.2-propane, bis(4-
hydro~y-2,5-di¢hlorophenyl)-2,2-propane, 4,4'-dihydroxybis-
phenyl-4,4'-dihydroxypentachlorobisphenyl, bi~(2-hydroxynaphthyl)
methane, 1,5-dihydro~ynaphthaiene, phloroglucinol, 1,4-di-
hydro~ynaphthalene, 1,4-bi~(4-hydroxyphenyl)cyclohe~ane, etc.
a9 well ~8 other oomplex polyhydric phenols, such a p~rogallol,
phloroglu¢inol and novalac resin~ from the condensabion Or
a phenol with an aldehyde in the presence o~ an acidlc condensa-
tion catalyst. For the nature and preparation Or novalac
resins, see bhe book by T. S. Car~well, Phenylpla~t, 1947,
page 29, et.seQ.
There can al~o be used 1,2-epo~y conbaining ~thers of
aliphatic polyhydric alcohols, such ~9 polyglycidyl ethers
thereo~, as ~or e~ample, thc diglycidyl ethers o~ ethylene
glycol, propylene glycol, trimethylene glycol, butylene glycol,
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dlethylene ~lycol, 4,4~-dihydro~ydicyclohe~yl triethylene
glycol, glycerol, dipropylene glycol, and the like, as w811
as ether containing more than two glycidyl groups such as
the glycidyl polyethers, glycerol, mannitol, sorbitol, polyalkyl
j alcohol, polyvinyl alcohol, and tbe like.
¦ These epoxide resins, or glycidyl polyethers as they are
~requently called ~ay be prepared by re~cting predetermined
amounts Or at least one polyhydric compound and one epihalo-
hydrin in an alkaline medium.
~hile it i3 prererred to u~e epichlorohydrin a~ the epi-
halohydrin in the preparation o~ the epoxide ~tarting materials,
other epihalohydrins such as epibromohydrin may be uqed
advantageousl~.
In ~he preparation Or the epoxide resins, aqueous alkali
i8 e~ployed to combine with the hsloeen Or tbe epihalohydrin.
The amount Or alkali employed should be substantially equiva-
lent to the amount Or halogen present and, prererably, should
be omployed in an amount somewhat in e~cess thereof. Aqueous
ml~tures Or alkali metal hydroxides, such as potas3ium hydroxide ~;
and llthlum hydroxide m~y be employed; although ror economic
rensons, sodium hydroxido is obviously prererred.
The product Or the above-described reaction instead
belng a singly slmplo compound i9 gener~lly a complex mixture
o~ glycldyl polyethers, but the principal product may be repre-
sented by the formula:
-C~2-(0-R-O-CH2-CHOH-CH2)n-0-R-O-CH2- H- ~2 ~ where n is an
lnteger o~ a series 0,1,2,3... and prererably having a ma~imum
va1ue Or 10~ and R represents a divalent hydrocarbon radical
Or a polyhydric co~pound, and preferably a dihydric phenol.
While ror any single molecule n 18 an integer, though the ract that
the obtained polyether is a mi~ture Or compounds, cause3 the
determined valuo ror n, Q.g., rrom molecular weight measure-
.
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1~83746
~ ents to be an ~verage which i9 not neces~arily a whole number.
- ~ Pre,erred polyethers ~or use with the hardening agents
Or this invention ~re prep~red rrom bi~t4-hydro~yphenyl)-2,2-
propano and contain a chain Or alternating glyceryl and 2,2-bi~s
(phenylene) propane radicals, ~epar~ted by intervening ethereal
oxygen atoms and hava a 1,2-epoxy equivalency between 1 and 2,
snd epoxide equivalent weight Or about 170 to about 250. A
particularly suitable material ror use in the invention i9 a
normally liquid glycidyl polyether o~ bisphenol-A having an
' 10 epo~ide equivalent weight o~ about 175 to 200 and a 1,2-epoxy
equivalency Or about l.ô to about 1.95.
The term "epoxy equivalency" hae employed in thi~ æpeci-
ication refers to the number of epo~y groups contained in the
s average molecule Or the de~ired material. The epoxy equivalency
is obtained by dividing the average molecular weight o~ the
polyepo~ide by the so-called "epoxide equivalent weight". The
epoxide equivalent weight i8 determined by heating one gram sample
Or the polyepoxide with an exceas Or pyridiniu~ chloride dissolved
i ln pyridine at the boiling point ~or twenty minute~. The excess
3 20 pyridiniu~ chloride is then back-titrated with 0.1 N sodium
¦ hydroxide to phenol-phthalein end point. The epoxide value
I is calculated by considering 1 HCl as an equivalent Or one
i epoxde. This method is u~ed to obtain all epoxide values
reported herein.
The novel compound~ o~ this invention are used in an
¦ amount sur~icient to harden the epoxy resin to an in~oluble
and inrusible poly~er. Generally, the amount Or hardening agent
u~ed should be at least a 5% stoichiometric e~coss, and as used
herein, 3toichiometric amount rerers to th~t amount needed to
rurnish one amino hydrogen ror every epo~y group to be
reacted. Particul~rly superior reaults are obtained when the
hardoning agent is e~ployed in rrom 5 to50/~ stoichiometric
exce~s .
1'~ 746
~,~ , The pre~erred hardening ~dditive wherein n has a v~lue
2, is prepared by stirriSng 6 molY phenol, 3 molq formaldehyds
~ (in the ~orm o~ a 36% ~ormalin solution) ~nd 0.5 weight percent
:,; of triethyla~ine, for about 2 hours. Nine mols o~ 3,5,5-
~:^ trimethyl-3-a~inomethyl cyclohe~yla~ine are then added to the
~1 .
~3 solution and the re3ultant solution is heated for about 1 hour
::~ st 100C. The water produced during the reaction is removed
.,. by dist$11ation
~', ' The hardening agent produced ii3 light yellow in color and
: 1 10 i8 h~ghly reactive with epo~y resins- Thus, compounds normally
~ used to accelerate the hardening action are not required in
.. 1 the practice Or this in~ention due to the high reactivity Or
the hardening agent~ o~ this invention with epoxy resin. . . .:
,~ A prererred composition Or the present invention ha~ a
luid consi~tency and is cap~ble of being app,lied as a uni~orm
coating that hardens to form a smooth, tough and adherent coating,
. J
~ possessing good me¢hanical and ¢hemical resistsnt properties. The
.~ composition ¢omprises:
(A) a liqu~d ep.oxy resin having terminable epoxy groups
and an epoxy equivalent rrom about 185 to 210 and a viscosity
below about 900 cps at 25C; ;,
(B) a ~iller material in an amount betweGn about 20 and ,~ :
,i 50 weight percent o~ said epoxy resin
: (C~ an er~ective a~ount of a dispersing a~ent for said .~:
~iller material; and
.
(D) the novel hardening additive of this invention
wherein n has a value o~ at lea~t 2, and prererably between 2 ~;~
and 5.
The process o~ the present invention.ror coating a
30 ~ubstrats comprises ~pplying to the surrace the above-idenbi~ied .~.
;~ co~po~ition and thon allowing the coating to cure without the
appl,ication of any.heat.
~ The liquid opoxy resins used in thls p~actice e~bod~-
:;(, . .. 5
_
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)83746
~ ,nt o~ the invention are the re~ction product3 Or epichlorohydrin
.~ . .
~ and diphenylol propane and having the following rormuls:
i-
.. :, . ~
C~12-CN-CNz ¦ ~ -O--CCH2- H-CII2 ¦ 0~ ~0CNZ-C~N2
These re~in3 have a viscosty below sbout 900 cp~ at 25 c
, and preferably between about 700 to 800 cps at 25C. The preferred
,~ .
value o~ n', in the above structural rormul~, is approximately
~` 0.2, whereby said re~in haa an approximate ~olecular weight
10 o~ 380 although the value o~ n' can vary between about O and 10.
It is understood that when the above epo~y re~in is produced,
.
it i~ a mixture of compounds that causes the determined value
for n' to be an average which is not neces~arily zero or a whole
number such as 1.
A particularly preferred re~in e~ibiting the above
.. : . - . . .
~?~` properties is Epon 82~ ~anu~actured by Shell Chem~cal Company.
- Other commercial liquid epoxy rosins which ars equivsl~nt to
bhe "~pon 828~' for the purpose~ of this invention, are "DER-331"~
sold by Dbw Corning Corporation and "Ciba Resin 50~, sold by
20 Ciba, Ltd.
D The term "epo~y equ~valent" re~er~ to ~be mesn ~lolec~lar
weight o~ the epoxy rssin divided by the number o~ epoxy
radicals per molecule, or in any case, the nu~ber Or gra~s Or
epo~y resin equivalent to one epoxy group or one gra~ equivalent
Or epoxide.
The amount o~ the novel hardener u~eful in the practice
Or this e~bodiment o~ tbe lnvention is an er~ective a~ount su~
.~
~icient ror causina the epoxy resin to harden. Generally, the
a~ount o~ hardener used i~ betweon about 35 and 40 ~ercent, and
30 prererably 35 percent by weight, based on the total weisht Or
the liquld epoxy re~in de3cribed above.
~ * T ~ EMARK -6-
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3746
- It is u~ually desirable to sdd the hardening agent
to the composition ~ust prior to use, particuiarly becau3e the
hardening agent renders the composition r~adily curable at or
near ordinary room temperature a~ well as under cold temperatures.
The compositions of thi3 invention pre~erably contain
from about 20 to 50 percent, and prererably 33 percent by weight
o~ the de~ired epoxy re~in, and at least one filler which i9 inert
with respect to the remaining ingredients Or the co~po~ition and
which have a particle ~ize up to about 50 microns. Generally,
the ~ize Or the filler particle~ range between about 25 and 50
microns.
Examples o~ suitable inert rillers ~nclude sand,
crushed ~hells, rock~, alu~inum powder, copper powder, quartz
powder, titanium dioxidel asbesto~, 5ilica, calcium carbon~te,
graphite, black iro~ oxide, silicon dioxide, diatomaceous
.. . ...
earth, alumino~licates, silicone carbideJ boron carbide, -
vermiculite, talc, mica and the like. Best re~ult~, in term~
Or corrosion inhibition are obtained with stainless steel
rlakes, steel powder, titaniPerrous ~agnetite oxide or
mixtures thereor.
The co~positions Or the invention al~o prererably
contaln agent~ to promote the adequate and uni~orm distribution
J of ~iller particles in the resin. Best results are achieved
when an effective amount Or fumed silica i9 employed. Gsnerally, ~ ~ -
between about 5 and 20 percent, and preferably 10 percent by
weight Or the liquid epoxy resin is employsd. The ~umed silica
not only prevents the settlement of the filler material in
; the composition, but also enhances the over-all anticorrosion
propertie3 o~ the coating composition.
As optional ingrsdients ~or the practlce Or this
inv~ntion, it i9 desired to include silicic acid in an amount .
o~ ~rom about 1 to 7 percent by weight, and prererably 3
percent by weight of the epoxy resin. The siliclc acid promote~
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37~6
~; the ~dhesion Or the ¢osting compositlon to wet, grea~y or oily
~; sur~aces. Another optional ingredient ~s silicon oil which is
employed in an~amount Or between about 1 and 2 ounces p~r 120
pounds o~ the total ba~e composition. The cilicon oil ~acili-
i~ tateq pigment distribution when pig~ants are utilized in com-
bination with the composition ~ this invention. The silicon
oil also decreases the sur~ace tension o~ the composition and
facilitate~ the ~preading o~ the ¢omposition on a part~cular
- substrateO
Compo~itions o~ this invention can al80 contain
~u~icient amount~ o~ aluminum hydro~ide a~ a flame retardant
~or the compo~ition. It i9 under~tood that other equivalent
compounds can be used a~ a substitute ~or aluminum bydroxide
altbough this compound iq the preferred ~lame retardant
additive ~or the invent~on. Generally, aluminum hydroxide is
present in an amount of up to 5 percent by weight of the ¢om-
position.
In ~eneral, the ~eparate components o~ the composition
can be admi~ed in any desired order and, i~ desired, combi~a-
tions of two or more components may be prepared initially withthe remaining components being added ~ubsequently. However,
as noted hereinbe~ore, it is usually desired to add the hardening
.
agent ~ust prior to use since ~he hardening agent renders the
¢omposition readily curable at or near room temperature with
no e~tern~l ~ource of heat be~ng required ~or hardening purposes.
When the above-described compositions are applied to
a given substrate, the coatings are ~ound to exhibit highly
,.
sati3~actory chemical resistance to ~et fuels, ga~oline,
~i3 heating oils, solvent~, etc., as well as high compression
strength, a low rate o~ shrinkage, good heat resistance,
satisfactory thermal coef~icient o~ expansion and adhe~ive
propertie~. -
The composition~ o~ thi~ invention mny be employed
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83746
ror the coating and~or repair o~ any type o~ surrace. These
sur~aces include, ~or example, wood, cement, met~l, gla~s,
and the like. The compo~itions are particulsrly suited ~or
use in treating metal surraces, such as, for example, copper,
aluminum, brass, steel, and iron ~urfaces. The sur~aces may be
in any type o~ structure, such as for example, pipes, piling,
rsaction ves eis, structural member~ of oil well drilling
plat~orms, containers ~or ~et fuel3, heating oils and solvents,
well ~ackets, heat exchange tubes, ~old~, and the like.
When the coating co~position~ of this invention are
~` applied to a particular substrate to impart chemical resistance,
the coating compositions are applied in an amount ~u~icient
to provide the chemical resistance desired. More speci~ically,
, the coatings are applied in an amount su~icient to pro~ide,
a ~ilm or coating o~ at least about 0.3 ~illimeters thick.
The coatings o~ the compositions can be applied to
substrate~ by conventional techniques known in the art including
spreading, spraying or dipping, and therea~ter per~itting the
.~. ::
composibion to cure at or below room te~perature to ~orm a bard,
durable coating having satis~actory chemical resistance and
being attractive in appearance.
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