Note: Descriptions are shown in the official language in which they were submitted.
1~5653~
THIS INV~NTïO~ lela~e~ to new a~le~ive co~*osition~, ~o
~ethods of bonding surface~ to~ether by means of these co~positions,
and to structures prepared by these m~thods.
The usefulness and versatility of epoxide resin adhesive
S compositions axe well known. Such coT~ositions are made up of
two essential constituents,the epoxide resin t i.e., a subst~lce
containing ~ore thsn one l,2-epoxîde group per ~v~rage molecule) and
a catalyst ,r curing agant which ea~es the ~poxide resin to
cro~s-link or itself reacts with the resin, these con~tituants
reactin~ to for~ a cured product ha~in8 8 hi~h specific adhesion to
a wide variety of substrates. P~rticulsrly useful ~hesives are
those that cure at room temperatures, say,20C, or at moderate
temperatures, s~y, at or belo~r 60C.
Most epoxide re3in adhesive compositions hitherto available lack
"green strength", that is to say~ they are not tacky before they
soiidify, an~ surfaces to be bonded to each other by the adhesive
must be held togPther by ~igs, clips, presses, or other ~e~porary
fasteners ~hilst solidi~ication takes place. Attemp~s have been
made to over~ome this disadvantage by dissolving certain high-m~lec~lar
2~ wel~;ht polymers in one or more components of the co~positior. to
act as a tac~ifier. In general, such compositions suffer fro~ the
~ w~ack that tne blend of the added polym~r and the epoxide resin
is viscous and beco~es tac~y too rapidly, leading to difficulties
in mixing it with other constituents of the compositions or in
ap?lying ;~ in a suffici2ntly ~hin layer. To cou~ter this, vola~ile
- 2 -
~L~5~S313
solvents could be incor?or~ted, but the solvent~containing compositions
cannot always be spread in layers of the desired thickness, the solven~
may attack the object to be bonded, and many types of solventS introduce
flammabilitv or toxicity ha~ards into the workshop
We have now found that the desired objective of producing an
epoxide resin adhesive ~hich can easily be mixed, dispensed9 and spread,
and which w~ll become tacky in use, may be achieved, withou~ the need
to add a volatile solvent, by employing certain combinations o~
apoxidc resins, polymercaptans, and polyenes with a curing agent for
the epoxide resin. The curing agent may be one of certain aliphatic
or cycloaliphatic polyaminessYhich cure the epoxide resin by a cross-
linking addition reaction; or it may be one of certain tertiary amines
which cure the epoxide resin by catalytically-induced polymerisation.
The present invention accordingly provides a composition comprising
ta) an e~oxide resin having, per average molecule,
more than one 1,2-epoxide group of formula
R2,
- CH - C - C - H
directly attached to oxygen, sulphur, or nitrogen, where either R
- and R2 independently of one another represent hydrogen, in which case
Rl denotes hydrogen or methyl, or R and R~ conjointly represent
-CH2C~2-, in which case R denotes hydrogen,
(b~ a polymercaptan having at least two mercaptan
groups per average molecule,
(c) a polye~e having, per average molecule, at least tws
ethylenic double bonds, each ~ to an atom of oxygen, r.itrogen, or
sulphur, the sum of such ethylenic double bonds and oî the mercaptan
groups in (b? being more than 4, and preferably from 5 to 8, and
(d? as curing agent for the epoxide resin, either a
compound havir,g at least three hydrogen atoms directly attached to
~OS6538
ali~hatic or cycloaliphatic amino nitrogen atoms or a tertiary amine
having at least one nitrogen atom directly attached to carbon atoms
of aliphatic or cycloaliphatic groups exclusively and at most two
hydrogen atoms attached to amino nitrogen atoms.
This in~ention further pro~ides a method for bonding suraces
together which comprises sandwiching between, and in contact wi.h, the
surfaces a curable compositioll of this in~ention, and also articles
havin~ surfaces bonded together by the aforesaid method.
A feature of this invention is that the compositions~presumably
through the reaction o~ the polymercaptan (b) with the polyene (c)~ rapidly
form a rubbery adhesive, which is sufficiently strong for many
purposes, in an extremely short time t typically, in less than 1 hour
and often in less than 15 minutes)~ which adhesive su`bsequently ir.creases in
s~rength, presumably due to reaction of the curing agent (d) with the epoxide
resin (a)7to give the high strength normally associated with epoxide
resin adhesives.
In the usual ~ethods of manufacturing epoxide resins, mi~tures of
compounds of differing molecular weight are obtained, these mixtures
ordinarily containing a proportion of compounds whose epoxide groùps
have undergone partial hydrolysis. The ~verage number of 1,2-e~oxide
groups per molecule of the resin need not be an integer of at least 2;
it is generally a fractional number but must in any case be greater
- than 1Ø
Examples of resins which may be used are polyglycidyl and
poly(~-methylglycidyl) esters obtainable by reaction of a substance
containing two or re carboxylic acid groups wit-n epichlorohydrin,
glycerol dichlorohydrin, or ~-methylepichlorohydrin in the presence of
~S653~3
alkali. S~ch esters m~y be deri~ed fro~ alipllatic carboxylic acids,
e.~., oxalic acid, succinic acid, adipic acid, seb~cic acid, and
dimerised or trimerised linol~c acid, fro~ cycloaliphatic carboxylic
acids such a5 hexahydrophthalic acid, 4~methylhexahydrophth~1ic acid,
tetrahydrophthalic acid~ and 4 me~hyltetrahydrophthalic acid, and from
aromatic carboxylic acids such as phthalic acid, isophthalic acid, and
terephthalic acid.
Other epoxide resin~ which may be u~ed include polyglycidyl and
poly( ~-methyl~lycidyl) ethers, such as those obtainable by reaction
of a substance containi~g at least two alcoholic hydroxyl groups or
at least two phenolic hydroxyl groups with th~ appropriate epichlorohydrin
or glycerol dichlorohydrin u~der alkaline conditions or~ al~ernatively,
in th~ presence of an acidic catalyst with subsequent treatment with
alkali. Such ethers ma~ ~e derived from aliphatic alcohols, for
~xample, ethylene glycol, diethylene glycol, triethyl~ne glycol,
and higher poly(ox~ethylene) glycols, propylene giycol and poly(oxypropylene)
glycols, propane-1,3-d~ ol, butane-1,4-diol, pentane-1,5-diol, hexane-1,5-diol,
hexane-1,2,6-triol, glycerol, l,l,l-trimethylolpropane, and
pentaerythritol;~rom cycloaliphatic alcohols such as quinitol,
l,l-bis(hydroxymethyl)cyclohex-3-en29 bis(4-hydroxycyclohexyl)~ethanP,
and 2,2-bis(4-hydroxycyclohexyl~propane; and from alcohols containing
aromatic nuclei, such as ~,N-bis(2-hydroxyethyl) aniline and
_ _
4,4-bis(2-hydroxyethylzmino)diphe~yl~thane. Preferably ~he ethers are
polyglycidyl ethers of an at lea~ dihydric phenol, for exsmple,
25 resorcinol, catechol, hydro~inone, bis(4-hydroxyphenyl)meth2ne,
~OS~i~;38
1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 4,4 _dihydroxyphenyl,
bis(4-hydroxyphenyl) sulphone, and phenol-formaldehyde, alkylphenol_
formaldehyde, and chlorophenol-formaldehyde novolac resins,
2,2_bis(4_hydroxyphenyl)propane (otherwise known as bisphenol A), and
2,~-bis(3,5-dibromo-4-hydroxyphenyl)propane.
There may further by employed poly (N~glycidyl) and poly(N- ~ methyl-
glycidyl) compounds, for example, those obtained by dehydrochlorination
of the reaction products of the epichlorohydrin and amines containing at
least two hydrogen atoms directly attached to nitrogen, such as aniline,
n-butylamine, bis(4-aminophenyl)methane, bis~4-aminophenyl)
sulphone~ and bis(4-methylaminophenyl)methane. Other poly (N-glycidyl)
c~m~dunds that may be used include triglycidyl isocyanurate,
N~NI-diglycidyl derivatives of cyclic alkylene ureas such as ethyleneurea
and 1,3-propyleneurea, and N,N'-diglycidyl derivatives of hydantoins
such as 5,5-dimethylhydantoin.
Compounds of formula I in which R and R conjointly represent -CH2CH2-
and R denotes hydrogen include bis(2,3-epoxycyclopentyl) ether,
2,3-epoxycylcopentyl glycidyl ether, and 1,2-bis(2 3 -epoxycyclopentyloxy)-
ethane.
Especially suitable epoxide resins are polyglycidyl ethers of
2,2_bis(4-hydroxyphenyl~propane or of a novolac from phenol ( which may
be substituted in the ring by chlorine or a hydrocarbon alkyl group
of from 1 to 4 carbon atoms) and formaldehyde, having an epoxide
content of at least 1.0 epoxide equivalent per kilogram.
Tha curing agent may be an alkylenepolyamine containing at least
two primary a~ino groups, such as diethylenetriamine, triethylenetetramine,
and their 1,2-propylene homologues, and he~amethylenediamine and its
-- 6 --
~S653l~
2,2,4_ and 2,4,4_trimethyl ana~logues and cycloaliphatic amines such
as 3-aminomethyl_3,5,5_trimethylcyclohexylamine (isophoronediamine).
Particularly suitable are poly(aminoamides) obtainiable in a known
manner by the reaction of a polyalkylenepolyamine having at least
four amino-hydrogen atoms per molecule with an at least dicarbocylia
acid or an amide-forming derivative thereof (i.eO, a derivative
in which carboxyl groups are replaced by groups~ such as carbalkoxy
groups each of two to six carbon atoms, whieh react with a primary
or secondary amine to produce amide groups) in sueh a manner that
the product eontains, as already ind~cated, at least three amino-
hydrogen atoms per molecule. me carbo~ylic acid is preferably a
dimerised or trimerised ethylenically-unsaturated aliphatic monocar~
box~ic acid such as linoleic acid; it may be modified by incorpor-
ation of styrene or other aromatic vinyl compound during oligomeri-
sation, so forming an ara-~;phatic~acid.
Also suitable are adducts of such alkylenepolyamines and
poly(aminoamides) with mono- or di-1,2-epoxides (for example,
ethylene oxide, propylene oxide, and diglycidyl ethers of alcohols
and phenols), it being understood that the adduct itself contains
at least three hydrogen atoms directly attached to aliphatic or
cycloaliphatic amino nitrogen atoms.
Suitable tertiary amines include N-benzyldimethylamine,
pentakis (N-methyl)diethylenetriamine, tri-n-amylamine, triethyl-
amine, triethanolamine,Mannich bases of the formula XIX set out
hereinafter, especially tris(dialkylaminoalkyl)phenols such as
2,~6-tris(dimethylaminomethyl~-phenol, and primary-tertiary
amines, for example ~N-dialkylalkylenediamines
~ 7 --
- ~05653~3
such as N,N-dieth~lethane-1,2-diamine, N,~-dimethylpropane-l,
3-diamine, and ~-(2-a~inoethy])pinera~ine~
An efective amount of the curing agent (d) is employed.
The proportion will depend upon its chemical struct~lre and
the pr~perties sought in the curable composition and in.its.cu;red
produ~t. The optimum proportion can readily be determined by
methods familiar to tnose skilled in the art. When the curing
agent is one having a~ least thr~e hydrogen a_oms directly attached
to aliphatic or cycloaliphati.c amir.o-ni..rogen atoms there ~ill
nor~aliy be used from GbOUt 0. 8 to 1.2 amino-hydrogen equivalents
of the amine per 1,2-epoxide equivalent of the epoxide resin.
When the curing agent is a tertiary amine having at least one
nitrogen atom attac.hed directly to aliphatic or cycloaiiphat~c
groups exclusively, ~nd has at ~ost two hydro~en atoms attached
to amino nitrogen atoms there is g~erally usPd fro~ 1 to 40
parts by weight per lOQ parts by weight of the epoxid2 resin.
A wide range o~ polym2rcap;~ns is suitable for use as component
(c) in the com?osition o. this. i~ven-ion. Preferabl~ there are used
~6S38
polymercaptans con~aining up to 6 mercaptan groups per molecule.
One class comprises esters of monomercaptancarboxylic acids
with polyhydric alcohols and of monomercaptanmonohydric alcohols
with polycarbocylic acids.
rther preferred such esters are of the formula
rOH 1
~ ~ b(d)
[ R3 ~ (Co)co(co)dR S~ II
\ COO~I ~
~ ~ ¦b(C)
where
R represents an aliphatic or araliphatic hydrocarbon radical
of at least 2, and preferably at most 60, carbon atoms, which may
10contain not more than one ether oxygen atom,
R represents a hydrocarbon radical, which may contain not
more than one carbon~loxy group, and is preferably of from 1 to 4
carbon atoms,
a is an integer of from 2 to 6,
b is zero or a positive integer of at most 3, such that
(a + b) is at most 6, and
c and d each represent zero or 1, but are not the sameO
Yet further preferred esters are polymercaptans of formula II
which are also of the formula
R (OCGR SH)a III
where
_ g _
1(~56S3~
a has the meaning previously assigned,
R is an aliphatic hydrocarbon radical of from 2 to 10 carbon
atoms, and fH3
R6 denotes -CH2-, -(CH2)2-, or -CH-
~
Also preferred are mercaptan-containing polyesters, i.ncluding
esters of monomerca ~andicarbocylic acids, of formula
R9 ~ )c- ~()d~ R7~0)d C()c - R SH ) IV
where
c and d have the meaning previously assigned,
e is an integer of from 1 to 6,
R represents a divalent organic radical, linked through a
carbon atom or carbon atoms thereof to the indicated ~0- or -C0- units,
R represents a divalent organic radical, linked through a
carbon atom~ or carbon atoms thereof to the indicated --SH group and
-0- or -C0- unit~ and
R represents an organic radical, which must contain at least
one -SH group when e is 1, linke.dthrough a carbon atom or carbon
atoms thereof to the indicated -0 or -C0- unitO
Preferably, R denotes, when c is zero, a saturated aliphatic
hydrocarbon chain of 2 to 250 carbon atoms, which may be substituted
by methyl groups and by -SH groups and which may be interrupted by
ether oxygeniatoms and by carbonyloxy groups; while, when c is 1,
R preferably denotes
(a) a saturated al,phatic hydrocarbon group of 2 to 10 carbon
atoms, which may bear an -SH group,
-- 10 --
6538
(b) a cycloaliphatic-aliphatic hydrocarbon group of 5 to 34
carbon atoms, which may contain ethylenic unsaturation, or
(c) a mononuclear arylene hydrocarbon group of 6 to 12 carbon
atoms.
R8 preferably denotes, when c is zero, a saturated aliphatic
hydrocarbon group of 1 to 3 carbon at~msD which may bear a carboxyl
group~ and~ ~hen c is 1~ R8 preferably denotes a saturated allphatic
hydrocarbon group of 2 to 4 carbon atoms which may be substituted by
a hydroxyl group or by a chlorine atom.
~0 R preferably denotes
(a) an aliphatic or cycloaliphatic-aliphatic
hydrocarbon group of 2 to 51 carbon atoms, which may bear at least
on -SH group.
(b) a mononuclear or dinuclear arylene hydrocarbon group
of 6 to 15 carbon aeoms~
(c) a chain of 4 to 250 carbon atoms, interrupted by at
least one ether oxygen a~om and optionally substituted by at least
one -SH group~ or
(d) a chain of 6 to 750 carbon atoms, interrupted by
at least one carbonyloxy group, optionally interrupted by at least
one ether oxygen atom and optionally substituted ~y at least one
-SH group.
Also suitable are esters and ethers which are of the general
formula
653~
i ~O~alkylene)f OH jh
~O-alkylene)fO(CO~ IR ~ V
I
where
each "alkylene" group contalns a chain of at least 2 and at
most fi carbon atoms between consecutive oxygen atoms,
f is a positive integer, preferably such that the average
molecular weight of the polymercaptan is not more than 10000?
is ~ero or 1,
H is zero or 8 positive integer such that (h ~ ~) is at most
6,
is an integer of from 2 to 6,
R10 represents the radical of a polyhydric aloohol after removal
of (h + i) alcoholic hydroxyl groups, especially an aliphatic
hydrocarbon radical of:from 2 to 10 carbon atoms, and
R 1 represents an aliphatic radical containing at least one
mercaptan group.
~ lkylenell units in individual poly(oxyalkylene) chains may
be the same or different and ~hey may be substituted by, e.g.9 phenyl
or chloromethyl groups. Preferably they are -C2H4- or -C3H6- groups~
Preferred amongst the compounds of formula V are ~he esters of
formula _ ~
5 / ~(O-alkylene~ OH ~ h
~(-alkYlene)fococku2ksu 1 Vl
and ethers of formula
-12-
;53~3
¦ (0_alkylene)fO~ j h
R ~ I VII
~` (O-alkylene)focH2cHcH2sH
OH
where
"alkylene", R5, f, h, and ~ have the meanings previously
assigned, and
k is 1 or 2.
Yet other suitable polymercaptans are mercaptan-terminated
sulphides of the general formula
HS - _ R12(o~ (CHO) R SS i R (0) (CH0) R SH
R13 - R13 VIII
where
each R12 denotes an alkylene hydroca}bon group con~aining from
2 to 4 carbon atoms,
o R13 denotes -H, -~H3, or -C2H5~
m is an integer which has an average value of at least 1, and
is preferably such that the average molecular weight of the
sulphide is at most 10000, and
either n is zero, in which case p and ~ are each also zero,
or n is 1, in which case p zero or 1 and q is 1.
The preferred sulphides are those of formula VIII where
R 3 denotes hydrogen and n and ~ are each 1, m being such that the
molecular weight of the sulphide is from 500 to 8000.
-13-
iO5GS38
Another class of polymercaptane comprises mercaptan terminated
poly(butadienes) of the formula
H R R14
l I
HS- - (CH2~ - C~CH2 ~ ~C~l2 C )u ~ -. -SH IX
or 14 ~
H ~ C \- ~X - - CH2. - ~CH215~U ~ - SH
l ~ t r X
where
each Rl4 represents -H or -CH3,
R represents -CN, COOH, -CONH2, -COOR , -C6H5, or
~OCOR16, ~here R16 is an alkyl group of one to eight carbon atoms,
t is an integer of at least one,
u is zero or a positive integer, and
r is an integer of more than one, p~eferably such that the average number
molecular weight of the polymercaptan is not more than 10000.
Preferably the polymercaptans of formula IX are also of the
formula
-14
1~653~
HS ~ CH2CH = CHCH2 ~ --~CH2iH ~ ]
and those of formula ~ are correspondingly of the formula
HS ~ CH2 ~ ~CH2CH)~ ~ SH XII
where
v is either zero, in which case w is 1, or it is 1, in which
case w is an integer of from 2 to 5, and
x is an integer such that the average molecular weight of the
polymercaptan is at least 1250 and at most 5000.
Yet another suitable class of polymercaptans comprises the
mercaptan-terminated oxyalkylene compounds of the general formula
~14 R14
RS (CHCH20)y CHCH2SH XIII
where each R has *he meaning previously assigned and X is an
integer of from 1 to 4.
A still further class comprises poly(monomercaptancarboxylates),
- especially the thioglycollates and mercaptopropionates, of tris(2-
hydroxyethyl3 isocyanurate or of tris(2-hydroxypropyl) isocyanurate,
i.e., the compounds of formula
ios6~s
~14
NGH2C~ S~
/\
C~ CO
Rl OC~CH2ll NCH2CHOCQR SH XIV
R14 CO R14
where
R17 denotes -H or a group -CO~SH, and ea^h R6 and R14 have
ehe meanings previously assi~ned.
S Polyenes preferred ~or the purposes of this invention have a~
: average molecular wei~ht of ~ot more than 2000 snd they contain a~
least two ethylenic double bonds each ~ to a c~rbo~ylo~y ~roup,
e~pecially în the fo~m of ~aleic acid residues of formula
,
--OCCH~ CO_
Il Il XV
O O
directly attached at ea~h e~d to cRrbon ~tom~, or in th2 for~ of
itaconic acid residues of fo~mula
~2CO~W
: I ~ 2 i~
directly attached at each end to carbon atoms9 or in the form of
- acrylic residues of for~ula
- CC - C~2 X~ll
16 _
. ` - ` ':.''' ` ' ~,1
~05~;38
directly attached to carbon atoms, where R denotes -H, -Cl,
-Br, or an alkyl group of 1 to 4 carbon atoms3
Preferably the polyenes contain, per molecule, up to six
ethylenically-~nsaturated units of formula XV, XVI, or XVII.
Particularly preferred polyenes are maleic esters of
poly(oxyalkylene) polyols and contain the repeating unit
_ rO-alkylene OICH = C~CIl XVIII
L l
where~'alkylene" has the meaning assigned above.
Preferably the polymercaptan is employed in a quantity sufficient
to supply from 0.8 to 1.1 mercaptan groups per said e~hylenic
double bond of the polyene, and the compositions contain from 10 to
150, and especially up to 75, parts by weight of the polymercaptan
plus polyene per 100 parts by weight of the epoxide resin. The
optimum amounts for a particular composition may readily be
ascertained by simple experiment.
Desirably, at least one of the polyene and the polymercaptan
has an average molecular weight of not more than 1000
The compositions may be heated, e~.g., at temperatures of from
35 C to 150 C, to increase the rate of curing, but often they
will cure sufficiently rapidl~ at room temperatu~e for most
purposes.
- ~)S6538
Conventional accelerators for promoting the curing of the epoxide resin
~a) by its curing agent (d) may also be included, particularly when
that agent is a poly(aminoamide). Such accelerators include
aliphatic amines containing at least one tertiary amino group
and at most one primary amino group, such as N,N-dialkylethane-l,
2_diamines and N,N-dialkylpropane-1~3-diamines, especially the
N~N-dimethyl and N,N,-diethyl derivati~es, and also Mannich bases
of the formula
R19(CH2NR R )a
X~
~0 where
al is an integer of at least 1 and is preferably 3 or 4,
R represents the radical of a mononuclear or polynuclear
phenol, which may be monohydric or polyhydric, the said radical having
free valencies, and
each R represents an aIkyl or hydroxyalkyl group of up to
four carbon atoms.
A preferred Mannich base is 2,4,6-tris~dimethylaminomethyl)
phenolO
me compositions may also contain an accelerator for the
reaction between the polyene and the polymercaptan, this accelerator
usually being an organic or inorganic Br~nsted base or a ~ree-radical
catalyst. me latter are of general applicability and include
organic or inorganic persxides and pers~lts such as benzoyl
peroxide, hydrogen peroxide, ~ert.butyl hydroperoxide, di~ propyl
peroxydicarbonate, and ammonium persulphateO
- 18 -
~56~3~
For the preferred polyenes, i.e., those ha~ing ethylenic double
bonds a to carbonyloxy groups, Br~n3ted bases may be ~sed instead. Examples
of suitable Br~nsted bases sre pri~ary, secondary, ~nd tertiary
amines, such as triethylamine, N,N-dimeehyl~ni~ e, and
N-ben~yldimethyi~ine, lower alkanol2mines ( e.g., m~no-, di-t and
tri-eth~olamine), lower alkylenepolyaminss ( e.g., ethylenediamine,
diethylenetriamine, triethylenetetramine 9 te~raethylenepentamine,
propane~l,2-diamine, propane-1,3~digmine, and hexamethylenedia~ine),
also quater~ary am~onium bases such as tetramethyla~onium ~ydroxide,
and ~ater-soluble inorganic hydroxides ~ especially sodiu~ hydroxide)
and inor~anic salts such as trisodiu~ pbosphate, sodium carbonate,
sodium bicarbonate, sodium pyrophosphate, snd sodiu~ acetate.
Of course, some curing agents for epoxide resins are also Br~nsted
bases, as are some accelerators for the curing of epoxide resins,
and when such a curing agent or accelerator is used there is
normally no advantage in employing another such base to promote the
reaction between the polymercaptan and the polyenes.
Optionally, plasticisers may be incorporated and these include
dibutyl phthalate, dioctyl phthalate, and tricresyl phosphate.
20 There may also be present so-called reactive diluents; especially
monoepoxides such as n-butyl glycidyl ether, iso-octyl glycidyl ether,
- phenyl glycidyl e~her, cresyl glycidyl ethe~s, glycidyl acrylate,
-- lq --
:~5~;~38
glyci~l meehacrylate~ a~d glyci~yl esters of br~ched tertiary,
aliphatic monocaribo~lîc acids. The co~ositions may also
con~ain fillers, colouring matter, flow-control age~ts, and
flame inh~bitors. Suitable extenders and fillers are asphalt,
bitum~n, glass fibres, ballotinig mica, suartz flour, calcium
carbonate, talc, cellulose, kaol n~ wollasto~ite, ~nd colloidal
silica having a large specific surface area-
The co~positions of the present i~vention may be ~upplîed
a~ a twc.-part psck; preferably~one part contains the epoxide
resin (a~ and the polyene ~C~ and the other the curing agent G~)
and the polymercapt~n (~), bacause~otherwise, the epoxide resin
may be cured pL-ema~urely on storage by mean8 of the polymercaptan,
and further, the curing age~t ~d),unless it is exclusively a tertiary amine,
react a. the ethylenic double bonds of the polye~e (c~. Because,
too, poly~ercap~anc2rboxylates reAct on prolo~ged contact with
~liphatic amines, it is preferred, ~here the co~po9itio~ iS to
be packaged in parts, to use as component (b) a poly~ercaptan ~hich
contains no car~oxylic ester groups.
A particularly pref~rred combination of curing age~t and
polymerca?tan for prolonged storage ;s a poly( minoa~a~le) and a
polymercaptan of the general fo-r~ula VII or VIII.
The co~sitions ~ay, of course, slso be supplied as a three-part
pacX, the epoxide resin being mixed with the polysne ~c).
rne following Exac~ples illustr~te the i~vention. Unle~s
o~herwi3~ indica~ed, par~s are by weigh~. Temperatures ar i~
degrees Ce;sius.
~ 20 -
:lOS653B
Pol~mercaptan A
is substantially of the average formula
CH2 - _ _
I f 3 1
CH _ ~ CH2CH)b OCH2CHCH2SH 3
CH2
where bl is an integer of average value 2,5 and was prepared as
described in United States Patent Specification No. 3258495.
Polymercaptan B
is the commercially-available po~ysulphide substantially of the
average formula
US ~ CH2CS2l)cH20 CH2CH255 ~H2Æ120CH20C112CH25H
Pol~mercaptan C
is of the formula
CH3CH - r T 3
CH2 - L(OC~2CH) OCOCH2SH ~ XXII
~, where cl is an integer of average value 3.16. The preparation
of mercaptancarboxylates of polyoxyalkylene polyols such as
Polymercaptans C to F and H is described in British Patent Specification
No. 1278934.
Polymercaptan D
lS of the formula
~056538
CH~ 3
CH- ~ ~OCH2CH~d OCOCH2SH ¦ XXIlI
CH2
where d is an integer of average value 3.69.
--1
Polymercaptans E and F
are of formula XXIII, where dl is an integer of average
value 5.41 and 7~14, respectively.
is the tetrakis(3-mercaptopropionate) of pentaerythritol.
Polymercaptan H
is of the formula CH3
_
C ._--CH2 (OCH2CH) e OCOCH~SH XXIV
where el is an integer of average value 2.~5.
Poly~erca-2tan J
is a hydroxy7-terminated polyester from l,l,l-trimethylolpropane
( 1 mol.)~ adipic acid ( 3 mol.,), and butane-1,4-diol ( 3 mol.),
~sterified with 3 mol. of 3-mercaptopropionic acid, prepared by .he
procedure described in British Patent Specification No. 1311090.
Poly~ercaptan K
- is a mercaptan-terminated butadiene-acrylonitrile copolymer
and has the general formula
andJor HS~ ~ CH2CH = CHCH2~ ~CH2CU~ ~ SH
~ CH t
2 3 7
_ 22 _
,. ~,
~1~56S3~3
Polyene I
This polyester is made in a conventional manner by the reaction
of maleic anhydride (3.06 mol.) with dipropylene glycol (3.21 mol.).
Polyene II
This polyester is prepared similarly Erom dipropylene glycol (2.1 mol.),
maleic a~hydride (l mol.), and adipic acid (1 mol.).
Polyene III
Butane-1,4-diol diglyci~yl ether OL epoxide ~ontent 7.4 equiv./kg
(108 g), itaconic acid (65 g), n-butyl glycidyl ether (28.1 g),
~-ben2yldimethylamine (2 g), and hydroquinone (0.2 g) are mixed and heated
to 120, when an exothermic reaction sets in, the tem?erature of the mixture
rising to 250. The product is rapidly cooled to 120 , and heated at that
temperature for one hour. Polyene III is substan~ially of ~he formula
1. ~
11 Il'
H - [ (CH2)40 CH2CHCH2CC - CCCH2CHCH2 - (CH2)3CH3 XXV
OH O O OH 5
Polyene IV
2,2-bis(4-Hydroxyphenyl)propane (114 g), n-butyl glycidyl et~er (130 g),
and ~-benzyldimethylamine (2 g) are hea~ed at 120 for 1 hour, then cooled
to 70. Maleic anhydride (98 g) is added and heating is con~inued at 120
for 100 minutes. The product, Polyolefin IV, is substantially of the for~ula
6~i38
CH3
~ ~ OCH2CHOCOC~ - CHCOH XXVI
Il IocH~
CH3 2 ( 2)3 3 I
Polyene V
A glycerol-propylene oxide adduct of average molecular weight 1000
(200 g ) is heated for 2 hours at 120 with 58.8 g of maleic anhydride in
the presence of 2.6 g of N-benzyldimethylamine.
Polyene ~l is substantially of the formula
1 2- ~ C~3
CH~ r(CH2CH)f OCCH = (~HCOH ¦ XXVII
2 3
where fl is an integer of average value 15.65.
Polye~e VI
.
This is made similarly from 100 g of a glycerol-propylene oxide
adduct of average molecular weight 300 and maleic anhydride (98 g ) with
3 g of tr_ethylamine as catalyst. Polyene VI is substantially of formula
XXVlI, where '1 is an integer of average value 3.59.
Polyene VII
Butane-1,4-diol (lOB g), maleic anhydride (98 gj, and xyle~e (135 g)
are heated together with stirri~g under reflux for 2 hours. Water formed
during the reaction is removed by azeotropic distillation using a Dean and
Stark trap. Toluene-?-sulphonic acid (2 g) is added and heating at reflux
is con~inued for a further 2 hours. The
- 2~ -
S05~53~
maxture is coolad ~o 50, neutralised wi~h a~ueous potas~ium
bicarbonate solution, ~he water and xylene are dis~illed olf,
and the resldue i8 filtered.
Polyene VII is substantially of the for~ula
~ O O
H_ O(CH2)4 OCCH ~ C~C O(CH~)40~ XXVIIX
Polyene VIII
A glycerol-propylene oxide adduct o~ average ~olecular
wei~ht 600 ( 600 g,) i~ hea~ed with 294 g
of maleic anhydride in the presence o~ 9 g of triethylamine for
2 hou~s at 120. Then n-butyl glycidyl ether of epo~ide content
7.7 equiv./kg. ~ 331 g) is added dropwise in an atmosphere of
nitroge~ and the mixture is heated for 1~ hours at 120.
Polyene VIII is sùb~an~ially of the formula
1 2 _ ~ 1 3
CH - t (ocH2cH)g OCCH ~ CHCOCH2CHCH2 t ~ 3 3 ~ XXIX
_ 3
~H2 ~
where ~1 is an integer of average value 8.76.
Polyene IX
Glycerol ( 92 ~,) and maleic anhydride
(294 g) are heated for 2 hours at 120 in the presence of 3.8 g
of N-benzyldi~ethylamine. ~hen 343 g o~ n-butyl glycidyl ether
(epoxide content 7.0 equiv./kg3 is added dropwise, an exothermic
- 2~ -
10S6538
reaction taking piace, and the mixtufe i6 heated for 2 hours at 120
in an at sphere of nitrogen.
Polyene IX is of formula ~YIX, where gl is zero.
Polyene X
2l2-bis(p-Glycidyloxyphenyl~propane, of epoxide content 5.2 equiv./kg
(384 g )~is heated for 2 hours at 120 with 144 g of acrylic acid in the
presence of 5.3 g of N-benzyldimethylamine as catalyst and 0.53 g of
~-methoxyphenol as polymerisation inhibitor
Polyene X is of the formula
.
1 ~ocH2c3c32occH = C~12~ xxx
CH3 2
- Polyene XI
is the tetrakis(methacrylate) of the adduct of p~ntaerythritol and
ethylene oxide, i.e., is of the formula
O
Il -' "'
C(C~zOCH2CH20CC = C.~2)4
~ CH3
1 Epoxide resin I
S
denotes a polyglycidyl ether of 2,2-bis(4-hydroxyphenyl)propane having
a viscosity at 21 in the range 200 to 400 poises: its epoxide content
is 5.1-5.4 equiv./kg. , ,
~ ~6 ~
105~538
~?oxide r~sin II
denotes a polyglycidyl ether of a phenol-formaldehyde novola~ of
average ~olecular weight 420. It has an epoxide content of
5.5-5.7 equiv.lkg.
Epox;de resin III
den~tes bis(4-(diglycidylamino)phenyl)methane having an epoxide
content of 7.5-8.5 equiv./kg.
E~xide resin IV
.~ ~
denotes a polyglyci~dyl ether of bis(4-hydroxyphenyl)~ethane
having an e~oxide content of 5.8 equiv./kg.
~=
denotes diglycidyl hexahydrophthalate having an epoxide content
of 6. 2-6. 8 equiv./kg.
Epoxide resin Vl
denotes l-glycidyloxym2thyl-3-glycidyl-5,5-di~ethylhydantoin having
an epoxide conte.lt of 7.0-7.4 equiv./kg.
Epoxide resin VlI
denotes 4-~diglycidyla~ino)phenyl glycidyl ether having an epoxide
content of 9.4-10.5 equiv.Ikg.
., /
.
- 27 --
1056538
Hardener I
denotes a poly~aminoamide) obtained by reaction of
diethylenetriamine with a mixture of dimerised and trimerised linoleic
acid: its amine value is 210-220 mg KOH/g
Hardeners II and III
denote polytaminoamide)s prepared in a similar manner to Hardener
I but having an amine value of 350-400 mg KOH/g and 290-320 mg ~OH/g respectivelY~.
Hardener IY
denotes a poly(aminoamide) prepared from a monomeric fatty acid
and an aIiphatic polyamine and.he.ving'an amine value of 580-620 mg KOH/g
Hardener V
.
denotes a ,similar poly(aminoamide) havi~g an amine value of 350-3~0 mg KOH/g
Hardener VI
denotes ~-~2-aminoethyl)piperazine
L5 Hardener_VII
denotes isophoronediamine
Hardener VIII
denotes a commercial mixture of 2~,4- and 2/4,4-~rimethyl-hexamethylene-
' - diamine0 Hardener IX
denotes triethylene~etramine
Hardener X
denotes N,N-diethylpropane-1,3-diamine
Hardener XI
. .
denotes 2~4,6-tris(dimethylaminomethyl)phenol
2~ -
1~5~S38
Hardener XII
:
denotes 3,3'-dimethyl-4Jd~'-diaminodicyclohexylmetllane
Hardener XIII
denotes a ~oly(o~ropYlene) triprimary amine ~i.e., a trihydric
aliphatic alcohol having three oxypropylene chalns a~ttached to the hydroxyl groups,
each terminated by a primary amino ~roup) of average molecular w~ight 400.
Accelerator I
.
is 2,4,6-tris(dimethylaminomethyl)phenol.
Shear strengths of joints were determined using aluminium
alloy strips 1.63 mm thick obtained under the designation "2L 73 Alclad"
which had been degreased, picXled by the process prescribed in the
British Ministry of Technology Aircraft Process Specification
DTD-915B, washed in runn;ng water1and dried ~t room temperature
("Alclad" is a registered Trade ~ark). Single lap joints 12 mm x
' 15 25 mm were prepared. T-peel strengtns were determined by the
procedure described in United States ~ilitary Specification
~: M~M-A-132. Sheets of "2L 61 Alclad", 0.056 mm thick and 24 mm wide
were used. Gelation times were determined by ascertaining when
- the mixture, stirred with a small wooden spatula, became a rubbery solid and/or
formed 'Istrings'' when pulled.
~,
i~ :
.
- 29 -
~1~565313
~X~MPLE. I
The n~ix~u~c~ shown in T~le ~ were prepared and their ~elation
times s~ room te~erature, on 10 8 ~amples, wPre measured.
TABLE I
. ~
Epo~ide . Accel- Polymer- Polymer- Polyene Polyene Gel
resin Hardener erator captan captan I II time
I I I A B (min~.)
_ _ . . _ .. ..
lO0 40 2 _ _ _ _ >60
100 40 2 _ _ 10 ~ 60
. 100 40 ~ ~ _ 40 _ > 6~
100 40 2 10 _ lO _ 0.5
100 40 2 50 _ lO _ 0.25
100 40 2 lO _ 40 _ 0.5
::100 40 2 _ 10 10 _
,. 100 55 5 10 _ 5 _
`~ 100 55 5 15 _ 5 _ 2.
s~ 0 S5 5 lO _ _ 10 3
lOo 55 - 5 lO _ _ 15 l.S
~:: I lO0 55 - 5 15 _ _ 15
s. loO 55 5 20 _ _ 15 1
:20 lOo 55 5 _ 15 _ 15 1
. lOu 55 5 _ ~ ~ l5
., .
In each experiment, except tne first three, the gelling mixtures became
tacky.
-3~ -
i~5~53l3
EXA~LE 2
To mixtures at room temperature com~rising 100 parts of~poxide resin I ~nd 23 or 7.5 parts, respectively, of
N-(~-hydroxypropyl)triethylenetetramine or N9N-dimethylpropane-l,
3-diamine were added 15 parts of Polyene II and 15 parts of
Polymercaptan A. The mixtures (lO g-portions~ gelled in half a
minu~e and one minute, respectively~ and became tacky.
EXAMPLE 3
_ _
Mixtures were prepared, each containing 55 parts of
Hardener I, 5 parts of Accelerator I~ and 15 parts of
Polymercaptan A. To a 5 g portion of each mixture was added wi~h
stirring 5 g portions of mixtures each comprising 100 parts of
Epoxide resin I and 15 parts of a polyene ( Polyenes I to XI).
In every case the admixtures gelled within 10 minutes a~ roo~
temperature~ a~d became tacky. If, however, either Polymercaptan A or the polyene
~' were omitted, geliing did not take place within 30 minutes.
EXAMPLE 4 _
Mixtures were prepared, each containing 15 parts of Polyene
II anà 1~0 parts of Epoxide resin I. Separately, mixturesj each
contai~ing 55 parts of Hardener I, 5 parts of Accelerator I,
and 15 parts of a Polymercaptan ( Polymercaptans C to J ;nclusive),
were made, and portions, each 5 g, of the epoxide resin mixture were
mixed with 5 g portions of the polymercaptan-containing mixture. In
- every case the admixtures gelled within lO minutes at room te~peratureJ and
25 developed tack.
31 _
1~5~S3~ ,
~urther composi~ion~ were pr~pared, e~ch containing 100 parts of !
Epoxide resin I, 55 parts of . Hardener . I, S parts of Accele~ator:
I, and cer~ain Polym~rcaptans and Polyenes as indicated in Table II.
The compositions were c~lred, either at room temperature for 24
hours or at 100 for 30 ~inutes, ~d the lap shear strengths and
T-peel serengths of bonds ~ormad with the compositions were measured.
TABIE II
_ . . __ Cured for , _ _ r _
Polym~rcaptan Polyene 24 hou-;~ nin~es et .
Desig- Desig-
n~tion Parts nation Parts lap shear lap shear T-peel
strength strength strength
(~Pa) meas~ed ~a) measured (N/mm~ measur~
_ _ at 22 at 22 at 60 at 22
A 10 I lS 22.229.1 24.5 1.3
A 15 I 15 24.632.3 21.4 1.4
A 20 I 15 21.334.3 21.8 1.6
A 15 V 15 _ 22.8 30.4 1.6
,. 15 A 15 ¦ VI 15 _ 22.8 21.7 0~9
A 15 VIII 15 _ 22.1 20.0 1.3
. A 15 IX 15 _ 22.1 20.6 1.2
: B 10 I 15 18.530.7 26.8 2.4 .
B 15 ¦ I 15 19.515.9 13.3 1.5
B 20 ¦ I 15 20.310.3 9.8 1.2
F 15 II 15 _ 31.2 21.7 2.8
G 15 II 15 _ 26.7 22.9 1.6
! 15 I~ l5 _ 28.3 24.8 1.4
:
- deno~es not deter~ined
In each case the compositions beca~ t2c~y.
- 32
1056~38
E ~'LE 6
Further compositions were prepared, each containing lO0 parts
of an epoxide resin, a stoichiometric amount of Hardener II, 15
parts of Polyene II, 5 parts of Accelerator I~and 15 parts of
Polymercaptan A. The compositions were cured for 30 minutes at 100
before determination of the lap shear and T-peel strengths. In all
cases the compositions became tacky before curing. The res~llts
are given in Table III.
TABLE III
_ __ ~. ~
10 Epoxide Hardener II Gel time Lap shear strength T-peel strength
resin parts (mins) (MPa) measured ( N/m~measured
at 22at 60 at 22
i I 55 1~ 34 29 1.2 ~
; II 60 3~ 18 13 1.8
III 55 3~ lS 14 1.1
IV 60 2 24 18 1.8
- V 70 ~ 31 10 3.4
V~ 75 2 27 15 1.8
VI~I 115 _ 24 22 l.S
When, for comparative purposes, Hardener II and Accelerator I were
replaced by a conventional mixed aromatic amine curing agent
- tm-Phenylenediamine and bis(p-aminophenyl)methane~by a conventional
anhydride curing agent C maleic anhydride or methyl tetrahydrophthalic
anhydride~,or by a con~entional latent curing agent ~dicyandiamide or
boron trichloride-n-octyldimethylamine complex~, the mixtures did not
gel within 30 minutes of mixing at room te~perature. These compositions
- 33 ~
~056S38
were therefore not suitable as tacky adhesives.
- EXAMPLE 7_
Example 6 was repeated, using 100 parts of Epoxide resin I and
various curing agents, the other components remaining the same as
in ~xample 6. The results are given in Table IV.
T~BLE IV_
~ _
Hardener Gel time Lap shear strength T-peel strength
. . (~Pa) measured (N/mm) measured
.` Type parts(mlns)at 22at 60 at 22
. _ _ . _
~ I- 100 4~ 29 11 2.6
:~ 10 III 85 1 25 13 3.0
IV 40 ~ * * *
~, V 60 ~ _ ~__ _ _
.'~ .
* these tests could not be carried out as the composition gelled
. before the specimens could be prepared.
EX~u~2LE 8
Example 6 was repèated, using 100 parts of Epoxide reSiD
I-7 55 parts of E1ardener II7 15 parts of Polymercaptan B or K, with ~he
other components the same as in Example 6. The results are given
in Table V.
TABLE V
.
Polymercaptan Gel ti~e Lap shear strength T-peel strengt'n ¦
mins~ (MPa~ measured (~/mm) ~easured
at 22at 60 at 22
B 1~ 1? 23 1.2
i ~ _ 3 _ ___ 23 2.7
__
:"
--
l~S6~;38
E~MPLF, 9
.
Example 6 was repeated, using 100 parts OI Epoxide resin I~15 parts of Polymercaptan A, 15 parts of Polyene II, and various
curing agents. The results are given in Table VI.
TABLE VI
.. _ . . _ _. __ __ _
Hardener Gel time Lap shear strengtlt T-peel strength
Type Parts (MPa) measured (N/nml) measured
at 23 at 60 at 23
__ _ __ _ . _
VI 13 25 sec. * * *
VII 22.5 20 sec. * * *
VIII 21 20 sec. * * *
IX 12 15 sec. * * *
X 10 13 sec. * *
XI 11 3~ min. 20.7 ~5.2 1.6
XII 32 11 min. 7.6 5.3 _
XIII 38 1~l6.0 _ _ 3.5
* these tests could not be performed as the composition gelled before
the specimens could be prepared
- denotes that tnis test ~as not carried out.
_35~ _
