Note: Descriptions are shown in the official language in which they were submitted.
. ::
2 1 ~ ~ 1 () f)
70.01.1993/f~
PAT 92 322 i~
FILE ~tdlN ~,-J~ !!iL D
T~T TRANSL~iI iJil FEC659
, ~, - . ~, .~ .
5 BASF Lacke + Farben AG, Mun~ter
Graft copolymer~, ~LC28~ for their preparat~on, ~ ~'
a~. 90_~ coat~ng compo~ttion~, and their u~e for coat~ng ~ ( ;
~-C~P_~ 9 contsiner~
~ 10 ' "';"'~
The present invention relates to graft copoly-
mers made from epoxy or phen~Yy resins, ethylen;~Ally
unsaturated monomers contAining acid anhydride yLUUp8
and further ethylen;cAIly unsaturated monomers. The
invention furthermore relates to a process for the
preparation of the graft copolymers, to aqueous coating
compositions which contain the graft copolymers, to a
process for the preparation of the aqueous coating
compositions, and to their use for coating packaging
containers.
High-moleclllAr-weight epoxy resins and ph~nQYy
resins are suitable for the preparation of coating
materials for sheet metal pAckAging containers, in
particular coating materials for the internal protec-
tion of sheet metal pa~kAging containers. Examples ofthe crossl;nking agents used are phPnolic resins,
-1 r ; ne resins and urea resins. Solvent-based coating
cr -sitions of thi~ type contain, due to the specified
application viscosity, a solvent content of between
- 2 -
60 and 70% by weight. If, as i~ the case in the surface
coating of two-part beverage cans, the coating i8
applied pre~ ;n~ntly by spraying, a further increase
in the solvent content usually results, which has the
consequence of Gonqiderable pollution due to solvent
emissions.
~ he advantages of aqueous coating systems by
cc ~rison are a significantly re~nce~ solvent
emission. In coating material~ for the internal protec-
tion of cans, it must also be taken into consideration
that these coating materials must meet strict foodstu~f '-
regulations. Coatings on the inside of cans must be i
stable on storage in contact with foodstuffs as the
contents. Coating materials for the internal protection
of cans in the foodstuffs and beverages sector must
therefore ensure adequate contents resistance, adequate
pasteurization stability and sterilization stability.
Solvent-cont~;n;ng coating materials for the
internal protection of cans which have good properties
J~,,>~I
and are based on combinations of epoxy re~ins and
phenol-formaldehyde resin~ or ~m; no resins have been
known for some time. In particular, epoxy resins ba~ed
on bisphenol A having a mean molecular weight of
greater than 3,000 give very resistant coating~
For use of such systems in aqueous -'; , the
epoxy resin must be modified by the introduction of
solubilizing y~OUp8 in such a way that a water-~oluble
or water-dispersible system is formed. Since resins
cont~;n;ng amino groups give stability we~knesses on
2 1 ~ 2 1 0 6
- 3
contact with the contents, which are predominantly
acidic, high-molecular-weight and thus predominantly
hydrophobic epoxy resins are rendered water-soluble or
water-dispersible by modification by means of carboxyl
groups. Thus, for ~Yr le, EP-A-6334 and EP-A-6336
disclose aqueous coating materials for the internal
protection of cans which are based on products of a
reaction of epoxy resins with acrylate copolymers
containing COOH groups. The epoxy esters formed are
converted into a water-dispersible form by neutraliza-
tion of the CArhOYyl yLOUp~ present in the acrylate
chain. The b-hydLG~y esters disclosed in the publi-
cations can be cured with the aid cro881 i nki n~ agents.
WO 89/1498 relates to aqueous dispersions which
are suitable as coating compositions for metal
containers for storing foodstuffs and beverages. The
coating c~ -~itions contain b;n~r mixtures prepared
by addition polymerization of relatively ;n~Yren~ive
monomers, such as, for example, styrene, in a reaction
medium cont~;n;ng modified epoxy resins. These are
obtA;ne~ by reaction of some of the epoY;~ groups with
ethyle~; CA 11y unsaturated monomers containing groups
which are reactive with epoY;Ae groups, such as, for
example, unsaturated carboxylic acids, and reaction of
further epox;~e groups with tertiary amines and with a
preaddition polymer which contains carboxyl groups and
contributes to the water-dispersibility.
However, the water-dispersibility of the
modified epoxy resins disclosed in said publications is
i771t~7qlo~
ii' _ 4 -
in need of improvement. This may be attributable to the
fact that the modification nece6sary to provide water-
dispersibility takes place only at the epoxide groups.
US Patent 4,212,781 and US Patent 4,308,185
disclose aqueous coating c. ~~sition~ for pAck~g;ng
containers, whose b;n~ers are prepared by free-rA~;c~
graft polymerization of ethylenically unsaturated
monomers, some of which contain carboxyl groups, in the
presence of an epoxy re~in, using at least 3% by
v~
weight, based on the total weight of the monomers, of
perox;~;c initiators. Use of the relatively large
amounts of initiator cleaves C-H bonds in the epoxy
resin chain, and acrylate side chA;n~ are grafted onto
the epoxy re~in main chain at these points, carbon-
lS carbon l;n~eo being formed. A disadvantage here isthe unavoitable relatively high initiator
concentration.
DE-C-27 47 818 discloses water-~;~persible
epoxy resins which are prepared by a process in which
an epoxy resin cont~;n;ng on average more than one
epoY;~e group per molecule is, if desired, chain-
exten~e~ by means of a ~;~h~nol and subsequently
reacted with a saturated carboxylic anhydride to the
desired acid number of from 5 to 200 mg of RO~/g. The
chain exte~io~ is carried out by reacting all the
epoY; ~e groups. However, the water-dispersibility of
the b;n~rs disclosed in this publication is in need of
improvement.
~' ~, ''',"'''' '
~ . !j~i !,.: ~. ,'A~ ~
21~13S
- 5 -
Finally, DE-A 2~ 08 880, 26 08 828, 26 08 839,
.
26 08 869, 26 08 901, 26 08 931, 26 08 941 and
26 08 942 disclose graft copolymers prepared by react~
ing liquid epoxide c. _ n~c having epoY;~e equivalent
5 weights of from 120 to 450 with ethylen;cAlly unsatura-
ted carboxylic acids and/or unsaturated acid anhydrides
having 3 to S carbon atoms, esters of acrylic acid, and
acrylonitrile and/or methacrylonitrile. In the working
examples, only unsaturated carboxylic acids are used,
but no unsaturated carboxylic anhydrides, which are
reacted with the epoxide groups of the epoxy resin. The
graft copolymers are used in solvent-free and low-
solvent coating and molding z~ itions. No aqueous
coating compositions are described.
lS The object of the present invention wa~ to
provide water-dispersible epoxy resin bin~rs which are
ea~y and simple to prepare and have excellent water-
di~persibility. The water-dispersible epoxy resins
sho~ be suitable for use in aqueou~ coating materials
for pA~A~ing containers, in particular in agueou~
coating material~ for the internal protection of cans.
The aqueous coating compositions prepared on the basis
of the water-dispersible b; n~r~ shoul~ be suitable for
.~
coating cans made from aluminum, t;nplAte and steel
which has been specially surface-pretreated in another
way. In addition, they ~o~ be suitable for coating
preserved-food cans, which must be resistant to a broad
range of contents, even under sterilization and
pasteurization condition~. The aqueous dispersions
~ .. !. c'~
- 6
should have a long shelf life, and they ~ho~ be suit- ~
able for application without flaws, in particular by -;
spray coating. The coating films resulting from the
aqueous coating - -~ition~ ~houl~ achieve at lea~t
the property level of conventional coating materials
for the internal protection of can~ with respect to
freedom from pores, contents resistance, adhesion to
metal sheeting, hardness, elasticity and flavor
neutrality, or even surpass this level. In order to
~. ~
~; 10 a~sess the contents resistance, the pasteurization or
sterilization stability of baked coating film~ with
respect to various test solutions should be used.
The object of the present invention is achieved
by graft copolymer~ of the type mentione~ at the
outset, which are characterized in that the graft
copolymers (a) are obtainable from ~-
A) epoxy re~ins having an epoY;~e equivalent weight ~ ;
of at least 500, preferably at least 700, and/or
phenoYy resins, ;~
B) carboxylic anhydrides cont~;n;ng at least one
polymerizable, ethylen;c~lly unsaturated double
bond per molecule, and from
. :- . .. . .
C) further ethylen;cAlly unsaturated -n~ -rs, at
least some of which may, if desired, contain a ~ -
carboxyl group,
where the ratio be~een the weight of A) and the total
weight of -r~ -r _ ~rents B) and C) i~ in the range ;~ ~-
f-om 90:10 to 10:90. ~ ~
~ ",,-,"",,,~
_ 7 -
If component C) i8 not a monomer contA;n;ng
cArhoYyl groups, the graft copolymers (a) obtained are
not water-dispersible and can thus only be used in
nonaqueous coating compositions. For use in water-
5 thi nnAhle coating materials, in particular can-coating
materials, adequate water-dispersibility of the graft
copolymers (a) is necessary. The present invention
therefore relates, in particular, to graft copolymers
(a) which are obtainable from
A) from 30 to 80% by weight, preferably from 50 to
75% by weight, of epoxy resins having an
epoxide eguivalent weight of at least 700,
preferably at least 1500, and/or ~h~n~Yy
resins, and
from 70 to 20% by weight, preferably from 50 to
25% by weight, of the sum of
B) carboxylic anhydrides cont~;n;ng at least one
polymerizable, ethylsnicAlly unsaturated double
bond per molecule, and
C) further ethyleni~Ally unsaturated monomers, at
least some of which contain a carboxyl group,
where the sum of the proportions by weight of
components A), B) and C) is in each case 100~ by
weight, from 0.02 to 0.5 mol of component ~) are
used per mole of c - ~~t A), and the acid number
of the graft copolymer (a) i9 in the range from 40
to 250 mg of KOH/g.
Component A) can be epoxy resins and/or p~noYy
resins. Examples of suitable epoxy resins are those
~'J,i~"j"~""
2 1 ~J ,~
.: - 8 -
ba~ed on bisphenols, preferably bisphenol A, it being
necessary for these to have an epoY;~e equivalent
weight of at least 500 or of at least 700. The suitable
epoxy resins contain secondary hydroxyl ~LOUp8 in
addition to the epoxide groups. According to the
present invention, these secondary hydroxyl groups are
reacted with the carboxylic anhydride component ~). It
is therefore preferred to employ according to the
present invention epoxy resins having a relatively high
epQY;de equivalent weight, since the epoxy resin
component should contain as many hydroxyl groups as
pos~ible. Preference is therefore given to epoxy resins
having an epoY;de equivalent weight of at least 700,
and particular preference i3 gi~en to those having an
epox~e equivalent weight of at lea~t 1,500. Suitable
epoxy resins are aromatic polyglycidyl ethers, which
are marketed, for example, under the tradenames
Epikote 1001, Epikote 1004, Epikote 1007, Epikote 1008,
Epikote 1055 and Epikote 1009.
According to the present invention, component
A) may also be phe~Yy resins, if desired mixet with
the epoxy resins described above. Suitable phenQYy
resins can be prepared from ~;phenols~ such as
bisphenol A, and epichlorohydrin, the phe~oYy resins
having a higher mean molecular weight. They are
hydroxyl yLOU~ contA;n;ng polyethers without terminal
glycidyl y-OUp8-
Examples of suitable carboxylic anhydrides
contA;n;ng at least one polymerizable, ethyle~;cAlly
' f : ~ 2 ' ~i '
- ~13~1n~
9 , ~
unsaturated double bond (component ~) are acrylic
anhydride, methacrylic anhydride, ~o~cenylsuccinic
anhydride, tetrahydrophthalic anhydride and maleic
anhydride. For the ~ppl;cAtion of internal coating~ of
beverage and preserved-food cans, preference i8 given
to acrylic anhydride and methacrylic anhydride. The
amount of unsaturated carboxylic anhydride employed is
varied ~epen~;n~ on the degree of grafting desired.
Examples of suitable ethylen;~lly unsaturated
,~.,.,;,
monomers of c' -ne~t C) are styrene, a-methylstyrene,
vinyltoluene, esters of acrylic and methacrylic acid,
such as methyl acrylate, methyl methacrylate, ethyl
acrylate, ethyl methacrylate, propyl acrylate, propyl
methacrylate, i8ep~0~yl acrylate, iisoyLopyl meth-
acrylate, butyl acrylate, butyl methacrylate, amylacrylate, amyl methacrylate, i~obutyl acrylate,
isobutyl methacrylate, hexyl acrylate, hexyl
methacrylate, t-butyl acrylate, t-butyl methacrylate,
decyl acrylate, decyl methacrylate, lauryl acrylate,
lauryl methacrylate, isobornyl acrylate, isobo---yl
methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl
methacrylate, octyl acrylate, octyl methacrylate, nonyl
acrylate, nonyl methacrylate, 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate,
3-hydroxypropyl methacrylate, 4-hy~LoAyLu~yl acrylate,
4-hydLoxy~tyl methacrylate, 5-hyd~oxyamyl acrylate,
5-hydroxyamyl methacrylate, 6-hyd oxyhexyl acrylate,
6-hydroxyhexyl methacrylate, 8-hydro~yocLyl acrylate,
8-hydroxyoctyl methacrylate, 2-hy-droxypropyl acrylate,
2 ~
,, .
-- 10 --
2-hydroxypropyl methacrylate, 2-hydro~ybu~yl acrylate,
2-1lydLo~yL~tyl methacrylate, 3-hyd~oxyLu~yl acrylate
and 3-hydro~ybu~yl methacrylate.
C~ --nt C) may also be ethylenlc~lly
unsaturated monomers cont~;ning a carboxyl group. The
use of these ethylsnicAlly unsaturated carboxylic acids
i9 necessary if the graft copolymers (a) are required
to have adequate water-dispersibility. Examples of
suitable monomers cont~;ning a carboxyl group are
acrylic acid, methacrylic acid and crotonic acid.
Monomer components B) and C) are preferably
methacrylic anhydride and/or acrylic anhydride, and
ethyl acrylate, methyl methacrylate, 2-ethylhexyl
acrylate and styrene respectively, and the acid
monomers are preferably acrylic acid and/or methacrylic
:. ,.::.,, i
acid. Particular preference is given, in the area of ; ~-
internal coating of beverage and prese~ved food cans~
to c~ ~inAtions of ethyl acrylate, styrene and
~- -
methacrylic acid, or ethyl acrylate, methyl
methacrylate, styrene and methacrylic acid, or
. ~ . .: ~ .
alternatively 2-ethylhexyl acrylate, methyl -
methacrylate and acrylic acid as ~ t C.
The graft copolymers (a) preferably have an ~ .
acid number of from 60 to 150 mg of XO~/g.
The graft copolymers according to the invention
can be prepared by various methods. In general, com-
ponent A) i8 reacted with the carboxylic anhydride -
CC~,-nPnt B) in an organic solvent at temperatures of
from 60~C to 160~C, preferably at from 100~C to 120~C, ~ -~
' '~
~1 ~t~1 ~ 6
.,., - 1 1 -
a reaction taking place between the secondary OH group3
of the epoxy or phenoxy resin and the anhydride group
of B). This reaction can be carried out, even when
high-molecular-weight epoxy or phen~yy resins are used,
at a high solids content, i.e. at ~olids contents of
from 80 to 95%. Suitable solvents are those which are
inert toward anhydride yLGu~s- Suitable solvents are
ketones, ethers, possibly esters and hydrocarbons.
Examples are methyl n-propyl ketone, methyl isobutyl
ketone, diisobutyl ether, n-propyl acetate, n-butyl
acetate, isobutyl acetate, n-propyl propionate, ethyl
butyrate and xylene.
In the reaction with the carboxylic anhydride,
it should be ensured that anhydrou~ condition~ exist.
If desired, a cataly~t is used in the reaction of A)
and B). However, the use of a catalyst is generally
unnecessary.
After the reaction of A) and B), the ethy-
leni~Ally unsaturated monomers of c~ _rent C) are
polymerized, in a ~econd step in the presence of the
product of the reaction of A) and B), in an organic
solvent at temperatures of from 60~C to 200~C,
preferably at from 120~C to 140~C, using at least 0.5%
by weight, based on the total weight of components B)
and C), of initiators which form free r~;c~l~. At
least 2.0% by weight, based on the total weight of B)
and C), of initiators are preferably used.
Examples of suitable initiator~ are dibenzoyl
peroxide, t-butylbenzoyl peroxide, tert-butyl
2 1 .3 ~
- 12 -
peroctanoate, cumene hydroperoxide and methyl ethyl
ketone peroxide, t-butyl perbenzoate, di-tert-butyl
peroxide, tert-butyl peroxy-2-ethy~h~xAnoAte, tert-
butyl peroxyiso~on~no~te, tert-butyl peroxyisobutyrate,
tert-amyl peroxy-2-ethylheY~noAte, peroxyketals, such
ao 2,2-di-(tert-amylperoxy)propane and ethyl 3,3-di-
(tert-amylperoxy)butyrate, azo compounds, such as
azobiscyclohPYAnPn;trile and azobisisovaleriate- The
initiator, dis~olved in some of the solvent employed
for the polymerization, is grA~uAlly metered in during
the polymerization reaction. The initiator feed
preferably takes from about 1 to 2 hours longer than
the monomer feed, in order in this way also to achieve
a good action during the post-polymerization phase. If
initiators having only a low decomposition rate under
the prevA;l;ng reaction conditions are employed, it is
also possible to initially introduce all or some of the
initiator.
The reaction is preferably carried out in the
presence of polymerization regulators in order to be
able better to control the molecular weights or the
molecular weight distribution. Suitable regulators are
preferably mercapto compounds, particular preference
being given to mercaptoethanol. Examples of other
possible regulators are alkyl mercaptans, such a3, for
example t-dodecyl mercaptan, octyl mercaptan, phenyl
mercaptan, octyldecyl mercaptan and butyl mercaptan,
and thiocarboxylic acids, such as, for eY~ le,
thioacetic acid or thiolactic acid. In the case of
2 1 3 2 1 3 ~
~; - 13 -
anhydride-functional comonomers, it must be en~ured
that the regulator cannot react with the cyclic
anhydride groups, or can only do 80 to a small extent.
In this case, preference is given to t-dodecyl
5 mercaptan.
These regulators are employed in an amount of
up to 2% by weight, based on the amount of ~ r to
be processed. They are preferably dissolved in one of
the monomer feed~ and added with the monomers. For
010 initiation of the polymerization, at least 2.0% by
weight, ba~ed on B) + C) of initiators are preferably
employed.
Suitable organic solvent~ for the free-r~;cAl
graft copolymeriz~t;on are - oAlcoholq having 3 to 18
15 carbon atoms, such as, for example, butanol,
isobutanol, propA~ol~ i~opropanol, pentanol and
isopentanol; and glycolethers, ~uch as, for example,
butyl glycol, butyl diglycol, hexyl glycol and p~vpy
lene glycol.
In the copolymerization carried out in the
second step, any desired solvent can be used or added.
In order to p~ven~ the b;~er gell;ng during the
preparation proces~ described at a high degree of
grafting, i.e. at high amounts of -c ~ ), either
the dilution with a suitable solvent must be selQcted
appropriately during the free-rA~icAl copolymerization,
either the product of the reaction of A) and B) being
initially intro~uce~ in an organic solvent and the
monomers and the initiator being metered in, or the
2 1 3 ~ S
1~'
- 14
product of the reaction of A) and B) being metered in -~
with the monomers C) and the pero~i~;C initiator.
Furthermore, the graft copolymers according to
:::
the application can be prepared by first polymerizing
monomer component~ B) and C) in an organic solvent at
temperatures of from 60~ to 200~C, preferably at from
,- .
120~C to 140~C, using at least 0.5$ by weight, based on
the total weight of B) and C), of initiators which form ; -
free rAA;~A1s, and subsequently reacting the copolymer
10 contA;n;ng acid anhydride groups which has formed with ~ ''
. .;.. ~.
A) in the temperature range from 60~C to 160~C,
preferably from 100~ to 120~C, catalysts being used if
desired. In this preparation process, it must be
ensured that organic solvents which are inert toward
acid anhydride groups are selected both in the prepara-
tion of the copolymer and in its reaction with the
epoxy and/or ph~nQYy resin. This preparation process is
not ~uitablo if --t -r ~ ent C) i8 OH-cont~in;ng
monomers.
In this preparation process, the cho;ce of
~olvent is thu~ limited both in the copolymerization
carried out first and in the subsequent reaction of the
anhydride groups of the copolymer formed with the
seco~Ary OH yLO~p8 from A), since the solvents used
must be inert toward acid anhydride groups. ~t.._ver,
the last-described preparation process is less sensi-
tive to the risk of gelling.
The first-described preparation process is more
advantageous for economic reasons, since, in an appro-
r~.
!~ ;s ' ~ t
S
,.;
- 15
priately desiqned reactor, the manufacturing process
can be carried out continuously from a possible epoxy
upgrade to a dispersion step in water without it being
necessary to handle inte ~ tes formed in between.~In
addition, this process offers greater latitude in the
choice of organic solvents. This proves to be
particularly advantageous in the preparation of aqueous
dispersions. In the first-described process, a lower
solvent requirement is only necessary, if at all, for
the first process step, which contain~ the reaction of
A) with B). Even in the case of relatively high- and
high-molecular-weight epoxy resins and ph~nsYy resins,
a solids content of from 80 to 95% can be used in this
first step.
A further preparation process, but one which is
not preferred, comprises reacting component A) with a
mixture of ~) and C) in a one-step process. In this
preparation process, which is preferably used in the
case of phsnnyy resins as component A), the free-
r~cAl copolymerization and the reaction of seco~Ary
OH y GUp~ of A) with the cyclic anhydride ~.vu~8 of ~)
proceed substantially simult~neo~l~ly. Natur_lly, only
solvents which are inert toward anhydride yLoups may be
used in this preparation process.
It is possible, and in some cases also desired,
for some or all of the epoY;~e group~ of the epoxy
resin which can be employed as component A) to have
been reacted with a compound which i3 reactive toward
epoxide groups. In this way, the properties of the
~ ?i', ~''', ~ ~'. ~,; i ~ : . ,
2 1 3 " ~
- 16
graft copolymer can be controlled. Suitable compound~
which are reactive toward glycidyl g~oups are, for
example, saturated - oc~boxylic acids andlor ~henol;c
compounds, ~uch as, for example, acetic acid, benzo;c
acid, saturated fatty acids having 6 to 18 c~rhon
atoms, such as, for example, palmitic acid, lauric
acid, myristic acid and stearic acid, bisphenol A,
bisphenol F, phenol, nonylphenol, dodecylph~nol,
cre~ols, xylenols and t-butylphenol. Al~o ~uitable are
alcohols, such as, for example, octanol, and primary
and seco~Ary amines, in particular hydroxylAmines,
~uch as ethanolamine and diethanol; ;ne. In the
reaction of the epoxy resin (A) with phenols and
saturated carboxylic acids, basic catalysts are
generally used; a suitable catalyst for the defunc~
tionalization with alcohols is, for example, boron
trifluoride. If the compounds which are reactive toward
epoY;~e groups ar~ alcohols or phenols, the blocking of
the epoY;~ function iB preferably carried out before
reaction with the cArbo~ylic anhydrides (B). If the
block;ng agents employed are CArboyylic acids, the
defunctionalization sho~ suitably take place before
or after the reaction with B), but preferably before
the reaction with C). If r ;nes are used as the
block;ng agents, the substantial reaction of the
epoY;~e groups of (A) can be carried out before or
after the reaction with (B) and before or after the
reaction with (C), but the reaction i~ preferably
carried out before the reaction with component (C).
21~21~
....
.. . .
~ - 17 -
The present invention also relates to a process
for the preparation of the graft copolymers described
above, which is characterized in that the epoxy resin
and/or phenoxy resin A) is reacted with the carboxylic
anhydrides contA;n;ng at least one ethylen;c~lly
unsaturated double bond per molecule B) in an organic
solvent at from 60~C to 160~C, preferably at from 100~
to 120~C, if desired u~ing catalysts, and the ethy-
le~; CA lly unsaturated ~ 8 C) are subsequently
polymerized in the presence of the resultant reaction
product in an organic ~olvlent at temperatures of from
60~C to 200~C, preferably at from 120~C to 140~C, using
at least 0.5~ by weight, based on the total weight of
the monomers B) and C), of initiators which form free
rAA;~Als~ it being possible, if desired, for at least
some of the epnY;~e groups from component A) to be
reacted with compounds which are reactive toward
epoxide groups.
The present invention furthermore relates to a
process for the preparation of the graft copolymers
described above, which is characterized in that the
carboxylic anhydrides B) and the ethylenicAlly
unsaturated - nr er8 C ) are polymerized in an organic
solvent at temperatures of from 60~C to 200~C,
preferably at from 120~C to 140~C, using at least 0.5%
by weight, based on the total weight of the -~ B)
and C), of initiators which form free rA~;cAl 8, and the
copolymer formed i8 subsequently reacted with the epoxy
resin and/or pheno~y resin in an organic solvent at
i ~, ~ 'r~r ~ -q.~
2 1 3 .~
.--; , ~ .
- 18 - ~
.::
from 60~C to 160~C, preferably at from 100~C to 120~C,
if desired using catalysts, it being possible, if
desired, for at least some of the epo~i~e groups from ' ~
component A) to be reacted with c- _unds which are ~ ;
reactive toward epo~;~e groups.
If all the epn~;~e groups of the graft copoly-
mer are reacted, it is necessary to add an external
~:
crossl;nk;ng agent to effect curing.
If the above-described graft copolymers a) have
an acid number in the range from 40 to 250 mg of K0~/g,
they are readily dispersible in water, and they are
suitable for use in aqueous coating compositions.
Howe~e~, they are also highly suitable for use in non-
aqueous, solvent-contA;ning coating c -sitions. The
present invention therefore likewise relate~ to aqueous
coating c~ -sitions which contain water-dispersed
binder solutions which contain
a) from 30 to 70% by weight, preferably from 35 to
65~ by weight, of the above-described graft
copolymers according to the invention,
b) from 0 to 30% by weight, preferably from 5 to 16%
by weight, of at least one phenolic and/or amino
resin as crosslink;~g agent,
c) from 1 to 7% by weight, preferably from 1 to 5% by
weight, of ammonia and/or an amine as neutralizer,
and
:: .
d) from 5 to 60% by weight of organic solvents,
where the sum of the proportions by weight of
components a) to d) in each case is 100% by weight. If
:-
~,',.,''".,'i'',~':, ~ . .'
2 ~ '3
1 9
desired, further water-dispersible b;n~ers, preferably
epoxy resins, can be used in addition to the graft
copolymers (a) in the aqueous coating composition~.
Suitable crossl; nk; ng agents b) are any deslred
phenolic resins, as long a~ they have the methylol
functionality necessary for the reactivity. Preferred
phenolic resins are products, prepared under ~lkAl;ne
condition~, of the reaction of phenol, sub~tituted
phenols and blsphenol A with f~ ehyde. Under such
conditions, the methylol group is 1i nk~ to the
aromatic ring either in the ortho-position or in the
para-position. Preference i8 given to phenolic resins
of the resol type which are based on bisphenol A and
contain more than one methylol group per phenyl ring.
Typical suitable amino resin~ (component b) are
mel~ ;ne, benzoguanamine and urea-fs -l~Phyde resins.
These are preferably used in the form which has been
etherified by means of lower Alcohsls, u~ually methanol
and/or butanol. FYr, les of suitable amino resins are
commercially available under the tr~enr -a Cymel,
Luwipal, Maprénal and Beetle. An example of a suitable
amino resin is hexamethoxymethylmelamine.
In addition to the con~enC~tion products with
formaldehyde, it is of course also possible to u~e
those with other aldehydes.
If the graft copolymer a) contains epoYi~
groups, it is not necessary for the coating compo~ition
to contain a crossl ink;ng agent b) to effect curing.
The composition i8 thus in this case self-croBsl ink; ng.
?~
3 2 1 ~
- 20 -
In the case of epo~i~e y-OU~ free graft copolymers a),
the use of a crosslinking agent is necessary.
The neutralizers (component c) employed are
from 1 to 7% by weight, preferably from 1 to 5%-by
weight, in each case based on the total weight of
components a to d, of ammonia and/or amines.
Preferred neutralizers c) are triethylamine
and/or dimethylethanolamine.
Organic solvents which are suitable as
component d) are, for example, monoAlcohols having 3 to
18 carbon atoms, such as, for example, butanol,
isobutanol, propanol and isopropanol, pentanol and
isopentanol; and glycol ethers, such as, for example,
butyl glycol, butyl diglycol, hexyl glycol and
15 propylene glycol. ;~
The solvents used are preferably, at least in
part, solvents which are also suitable as cosolvents ;
for the aqueous dispersion, e.g. butanol, butyl glycol ~ ~;
and butyl diglycol. The solvents are usually used in
20 amounts of from 5 to 60% by weight. ; -~
In addition to the h; n~9r solution described,
which is usually employed in amounts of from 5 to 60% -
by weight, preferably from 15 to 50% by weight, in each
case based on the total weight of the coating compo~
25 sition, the coating - ~_sitions may al~o, if de~ired,
contain pigments and/or fillers, further assistants and
additives, if desired further solvents and water, in
each case in conventional amounts.
~ 9 ~
2~'321~ 'J
- 21 -
Pigments and/or fillers are preferably employed
in amounts of from 25 to 35% by weight, based on the
total weight of the coating composition. Examples of
suitable pigment~ are titanium dioxide, for example the
products obtainable under the tr~en~ -8 Titan Rutil
RN 59, RTC 60, R 900 and RDI-S.
Suitable fillers are barium sulfate, such as,
for eYA le, the commercial products Blancfix micro and
Blancfix F; silicon AioX;~e, for example the commercial
~; lO product Qua ; - hl SF 600; potassium carbonate and talc.
The coating compositions preferably also
contain from 0.01 to 5.0% by weight, based on the total
.
weight of the coating composition, of further assis-
tants and additives, such as, for example, lubricants,
lS such as waxes, plasticizers, stabilizers, wetting
agents, dispersion aids, catalysts and surface-active
additives, individually or as a mixture. '
The aqueous coating compositions according to
the invention preferably contain from lO to 25% by
weight of organic solvents and preferably from 20 to
40% by weight of water, in each case based on the total
weight of the coating c~ -sition.
If the graft copolymer a) still contains
sufficient epoYi~s yLOUp3~ the use of a crosslink;ng
agent b) is unnecessary, i.e. the coating c~ ~_sition
is in this case self-crossl;nk;nq.
The present invention also relates to the ~-
process for the preparation of the ab~v_ described
aqueous coating compositions, which is characterized in
21.~
- 22 -
that the graft copolymer a), dissolved in an organic
solvent d) is at least partially neutralized by means
of ammonia and/or amine c), if desired the cro8~l i nki ng
agent b) and if desired further solvent d) and if
desired further conventional additives, if desired
pigments and fillers, are admixed, and the coating
composition iQ dispersed in water.
The graft copolymers described dissolved in
organic solvents, are at least partially neutralized by
addition of ~ -r;~ and/or r ;ne~. The r --;A and/or
amines are employed in an amount sufficient to render
the coating c sition water-disper~ible. The neutra~
lization of the organic h; n~r solution by means of
tertiary amines is preferably carried out in the
temperature range of from 60~C to 120~C. If desired
crossl;nking agents b), if desired cosolvents d)
necessary for producing a film with qood flow-out, and
if desired further cohveh~ional additives and if
desired pigments and fillers are admixed. The coating
composition is subsequently dispersed in water. It is
also possible first to p,ecsn~en~e the graft copolymer,
dissolved in an organic solvent, by means of the
crossl;n~;ng agent b), this being followed by
neutralization, if desired further solvent d) and if
desired further conventional additives, fillers and if
desired p;~ -nts being admixed, and the coating com-
position being dispersed in water.
The coating compositions according to the
invention cure at an object temperature in the range
$ ~
21~2~0G
- 23 -
from 150 to 400~C for a time of from 2 seconds to
10 minutes. They can be applied by rolling, knife
coating, spreading, spraying, flooding or dipping by
mean~ of conventional eq~ nt, the film subsequently
being oured to given an adherent coating. The coating
compositions are, in the case of internal coating
materials for cans, preferably applied by spray
coating. In the case of external coating materials for
cans, they are preferably Appl ie~ by roller coating.
The aqueous coating - ~itions according to the
invention can also be applied by Ano~
electrodeposition coating. In this case, the parts to
be coated are immersed into an aqueous bath based on
the above-described coating - ~-sitions according to
the invention and co~nected as the anode. ~y mean~ of
direct current, a film iB deposited on the cans, the
substrate is removed from the bath, and the film is
cured by h~k; ng.
The coating compositions are preferably applied
'3 20 as a one-coat finish, generally having a dry film
~h; ~kneB8 of from 5 to 25 lm.
The coating c. ~-sitions according to the
invention are suitable for coating packaging con-
tainers, in particular for the internal coating of cans
and the like. However, they can also be used for the
external coating of cans and the like. The pAckAq;ng
containers can comprise a very wide variety of
materials and have a very wide variety of geometries.
Suitable materials are, in particular, tin-free steel,
~?2la6
- 24 -
tinplate, and variou~ iron alloys, which may have been
provided with a passivation layer ba~ed on compounds of
nickel, chromium and zinc. The packaging containers can
be coated in the form of, for example, can halves, i.e.
bodies and lids, as 3-part cans and as 2-part cans
which have been drawn and ironed or deep drawn in
another -nn~r ~uch as, for example, beverage and
preserved-foot cans.
The aqueous coating c~ -6ition~ have a long~; 10 shelf life, and the coating films pro~ e~ from them
have an excellent pLopeLLy level with respect to
freedom from pores, contents resistance, adhesion to
metal sheeting, hardness, elasticity and flavor
neutrality. The resultant coatings have very good
pasteurization and sterilization stabilities. In
addition, the aqueous coating composition dispersions
are very stable, even when high-molecular-weight epoxy
resins and phenoyy resins are used, which is possibly
attributable to the fact that the high-molecular-weight
hydLop~ob;c constituents of component A) of the b;n~r
used are modified by the graft copolymerization in such
a manner that good water-di~persibility results.
The invention i~ de~cribed in greater detail
below with reference to working examples.
21~2~ n6
-
- ~5 -
Example 1: Preparation of an aqueous d~persion of
a~ anhyd~ fied epoxg acrylate
re~n
1.1 React$on of as epoxy r~in with a~ ethyle~c~lly
un~aturated a~hydr~de
1000 g of a ~olid epoxy resin of type 1007
(Epikote 1007 from Shell) having an epo~;~e equivalent
weight of 1751 g/mol are dissolved in 111 g of xylene
at 120~C in a four-necke~ flask fitted with stirrer,
reflux co~e~cer and thermometer. 5.5 g of methacrylic
anhydride (0.55~, based on the ~olid epoxy resin) are
added to the epoxy resin solution, and the reactor
content~ are kept at 120~C for one hour and then
diluted with 193 g of butyl glycol, 223 g of butanol
and 45 g of pentanol mixture.
1.2 Acrylatlon of th- r-act~on ~Lvd~_L from 1.1
1568 g of the reaction reaction from 1.1 are
warmed to 120~C in a four-necke~ flask fitted with
stirrer, reflux co~ er, two metering ve~sels and
thermometer. A pre-prepared mixture of 179 g of
methacrylic acid, 117 g of styrene and 128 g of ethyl
acrylate is metered into the reactor content~ at a
uniform rate over a period of two hour~ from the first
metering vessel. At the same time, a solution of 10 g
of tert-butyl perbsnzoate in 30 g of butyl glycol i~
added dropwise at a uniform rate over 2 1/2 hours from
the second metering vessel. When the feeds are
complete, the reactor contents are kept at 120~C for a
further three hours. The resultant product has an acid
- 26 -
number of 80.5 mg of K0~/g and a viscosity of 4.8 dPa ~
(30% strength solution in butyl glycol, plate-and-cone ~ ~ ;
' ,'' !C~.~
viscometer at 23~C) at a solids content of 71%.
1.3 Neutralization of the reactio~ product from 1.2 ~
1990 g of the reaction product from 1.2 are
warmed to 90~C in a four-necke~ flask fitted with
stirrer, reflux co~enC~r~ metering vessel and thermo-
meter. 542 g of demineralized water are carefully added
to the binder, and the mixture is subsequently
neutralized at 90~C u8inq 74 g of dimethylethanolamine.
The degree of neutralization i8 40%.
1-4 Preparation of an 9 ,~ dispersion of tbe
rea¢tlon pr~ rbto~--' from 1.3
.
2606 g of the h;n~sr from 1.3 neutralized by
the proce~ describsd are run out of the reactor at
80~C into 4561 g of demineralized water and are
dispersed over a period of one hour. The resultant
dispersion ha~ a ~olids content of 20% and an efflux
time (DIN 4 cup, 20~C) of 35 seconds.
20 ~Y~ le 2~ arat1On of an ?~ Y_ ~ d~spersion of
an anhydrld--modif~ed epoxy acrylat-
.
r-~in with oub~tant~al ~loc~q of the
epQx~ functions by means of benzoic
acid befor- the acrylation~5 2.1 Chain exten~1On of an epoxy resin hav~ng an
spc i~ eguivalent weight of 1700
663 g of a liquid epoxy re~in based on
bisphenol A and having an epo~;de equivalent weight of
187 g/mol and 111 g of xylene are weighed out into a
. " ~
~ ~ f ~
.' ', "~ :
- 27 -
four-necked flask fitted with stirrer, reflux co~en~er
and ~he - -ter and are heated with stirring. At 100~C,
337 g of bi8phe~01 A and 0.3 g of ethyltriphenylphos-
phonium iodide (Shell Catalyst 1201) are added. The
reaction mixture iB heated to 160-165~C. The supply of
heat is regulated so that the exothermicity which
occurs does not allow the temperature in the flask to
rise above a maximum value of 180~C. The reaction
mixture is kept at 160-165~C until a target EEW of 1700
has been reA~heA, and is then cool~d to 140~C.
2.2 Reaction of th- ~poxy re~in prepared as in 2.1
with an unsaturated CaLLG~yl~ C anhydride
1090 g of the epoxy resin solution from 2.1 are
heated to 140~C in a four-neckPA flask fitted with
stirrer, reflux cQ~Aenqsr and thermometer. 2~5 g of
methacrylic anhydride (0.25 g, based on solid epoxy
resin) are added, and the reactor contents are kept at
140~C for one hour, then cooled to 130~C and diluted
with 68 g of butyl glycol, 68 g of butanol and 14 g of
pentanol mixture.
2.3 ~ a¢tion of th- react~on Q~C~ _ L from 2.2 with
carboxyllc acid
1243 g of the reaction product from 2.2 are
warmed to 130~C in a four-neck~A fla~k fitted with
stirrer, reflux co~A~n~er and thermometer. 58 g of
benzoic acid and 2 g of dimethylbenzyli~mine are added,
and the reaction mixture i8 kept at 130~C until an EEW
of ~ 10000 g has been reA~heA, is then cooled and is
~.. t~ '. .c~
?
? ~ 7 ?~
-' 2~3213;~ :
.. . . -
- 28 -
diluted with 275 g of butyl glycol, 306 g of butanol
and 61 g of pentanol mixture.
2.4 Acrylat~on of the react~on product from 2.3
1932 g of the reaction product from 2.3 are
warmed to 120~C in a four-necke~ flask fitted with
stirrer, reflux con~enRer, two metering ves~els and
the - -ter. A pre-prepared mixture of 187 g of
methacrylic acid, 122 g of styrene and 134 g of ethyl
acrylate is metered into the reactor contents at a
uniform rate over a period of two hours from the first
metering vessel. At the same time, a solution of 10 g
of tert-butyl perbenzoate in 31 g of butyl gly~ol is
added dropwise at a uniform rate over the course of
2.5 hours from the seco~ metering vessel. When the
feeds are complete, the reactor contents are kept at
120~C for a further three hours. The resultant product
has an acid number of 79 mg of XO~/g and a vi~co~;ty of
11.6 dPa 8 (30% strength solution in butyl glycol,
plate-and-cone viscometer, D-cone at 23~C) at a solids
content of 62%.
2.5 Neutralization of the reaction p~o~L from 2.4
1376 g of the reaction product from 2.4 are
warmed to 90~C in a four-necked flask fitted with
stirrer, reflux co~Pnqer, metering vessel and thermo-
meter. A pre-prepared mixture of 33 g of dimethyl-
ethanolamine and 150 g of ~ ;npralized water is
metered into the reactor contents over a period of
15 minutes, the mixture i~ then kept at 90~C for a
~ ;
~ ~ A~
CA 02l32l06 l998-04-27
- 29 -
further 30 minutes, and then cooled to 80~C. The degree of
neutralization is 30%.
2.6 Preparation of an aqueous dispersion from the reaction
product from 2.5
1150 g of the binder from 2.5 neutralized by the
process described are run out of the reactor at 80~C into 1192
g of demineralized water warmed to 60~C, and are dispersed
over a period of one hour. The resultant dispersion has a
solids content of 27~6 and an efflux time (DIN 4 CUp, 23~C) of
60 seconds.
2.7 Preparation of various crosslinked varnishes for LUG caps
(twist-off caps) using the dispersion from 2.6
The dispersion prepared as in 2.6 iS tested with the
following crosslinking agents in two different ratios (95:5
and 85:15):
Cymel 1123 (American Cyanamid)
Luwipal B Oli (BASF AG)
Desmodur~ BL 3175 (Bayer AG)
Tests for flexibility on club cans, sterilization
stability (1 hour at 130~C) and stacking adhesive are carried
out. The varnishes are assessed as a system with a white
paint.
For each intermediate stage in the overall baking
process, the flexibility is assessed separately, i.e. without
high-bake (baking process for varnishes), with high-bake
*Trade-mark
26766-4
CA 02132106 1998-04-27
- 29a -
(ba~lng process for primers) and without or with baking for a
compound material. Sterilization is assessed without and with
high-bake.
26766-4
- ! 2 1 3 2 1 ~ ~
" .; . ,.
- 30 -
O ~ g
o ~ ~ ~ E ' ~ :
P~
o ~r -
o , ~ o o o
o :
.
,
O N K
o I ~ O O
--~ O
o o O X
O I N I ~ I ~ ~ ~; O ~ ~
O Jo ~o O O
C
U .¢
'; ~' : ':'~
N --I N O o o o
O ~O p ~ ~, .:
O ~ O O O
m q.
m ~
~~ ~ ~q S 3 ~3
~ ~ ~ U ~ O ~ ~ O
r 1~ ~,1 m ~ m m 3 3 ~
~ t r.
r~~ 3 .~ ,C
N _I O ~ O ~ . .C Ei
~ O~ .C 3 ~3 3 ~3 ~- '
N m~~1
r ~ ~ U U U U -- -- - - ~ ~d
~j rj t t
U 1 ~ cn U U C~ U U~
~ 21321~S
.
- 31 -
Example 3: Preparat~on of aD aqueous di~per~ion of
an anhydride-modified acrylated p~a-~Yy
re~in (~y~ EEW 10000)
3.1 Preparatlon of a ~ y re~in having an epo
egu~valent we~ght of about 10000
627 g of a liquid epoxy re~in based on
bisphenol A and having an epoY; ~e equivalent weight of
187 g/mol and 166 g of xylene are weighed out into a
four-n~ke~ flask fitted with stirrer, reflux con~en~er
and the ter, and the mixture i~ heated with
stirring. 373 g of bisphenol A are added at 80~C, and
0.5 g of ethyltriphenylphosphonium ;o~;~e (Shell
Catalyst 1201) are added at 100~C. The reaction mixture
is heated to 150-155~C. The supply of heat is regulated
80 that the exothermicity which occurs does not allow
the temperature in the flask to rise above a maximum
value of 155~C. The reaction mixture is kept at
150-155~C until an E~W of 10000 g/mol has been reA~he~
and is then cooled to 140~C.
3.2 Reactlon of th- epoxy re~in fro~ 3.1 w~th an
ethyl- ~c~lly un~aturated anhydr~de
1138 g of the epoxy resin solution from 3.1 are
heated to 140~C in a four-necke~ flask fitted with
stirrer, reflux co~n~er and thermometer. 5.0 g of
methacrylic anhydride (0.50%, ba~ed on solid epoxy
resin) are added, and the reactor content~ are kept at
140~C for one hour, then cooled to 120~C and diluted
with 528 g of butyl glycol, 556 g of butanol and lll g
of pentanol mixture.
. ' ' ~ ' ;~ '' "' ' "" '' ' '. ' ' " . "' . 't' ' '~' ' ' '
2 1 ~
- 3~ -
3.3 Acrylation of the reaction p~odu~ from 3.2
1953 g of the reaction product from 3.2 are
warmed to 120~C in a four-necked flask fitted with
stirrer, reflux con~nser, two metering vessel~ and
thermometer. A pre-prepared mixture of 175 g of
methacrylic acid, 115 g of styrene and 115 g of ethyl
acrylate is metered into the rsactor contents at a
uniform rate over a period of two hour~ from the first
metering vessel. At the same time, a solution of 10 g
of tert-butyl perbenzoate in 28 g of butyl glycol i8
added dropwiYe at a uniform rate over the course of
2.5 hours from the second metering vessel. When the
feeds are cGmplete, the reactor content~ are kept at
120~C for a further three hours and then further
diluted with 137 g of butyl glycol, 137 g of butanol
and 28 g of pentanol mixture. The re~ultant ~.odu~L ha~
an acid number of 73.6 mS of KOH/g and a vi~cosity of
5.6 dPa ~ (20% strength solution in butyl glycol,
plate;and-cone viscometer at 23~C) at a solids content
3.4 N utrallzation and di~persion of the reaction
p~od~c~ from 3.3
1474 g of the reaction product from 3.3 are
warmed to 90~C in a four-necked fla~k fitted with
stirrer, reflux co~e~er, metering vessel and thermo-
meter. 27 g of dimethylethanolamine are run into the
reactor contents over the course of 10 minutes, the
mixture i8 then kept at 90~C for a further 30 minute~,
1816 g of demineralized water held at 60~C are then
~132~0 ï)
_ 33 -
added over a period of one hour, and the mixture i8
dispersed at 90~C for a further hour. The degree of ;
neutralization is 30%, and the dispersion has an efflux
.. . : -:
time (DIN 4 cup, 20~C) of 27 seconds at a solid~
content of 20~
Examplo 4: Copolymerisation of an unsaturated
anhydride with ethyl~n1cAIly unsaturated
monomer- and o~ Q.--t reactlon wlth an
epo~y re~in ' ~ --
10 4.1 Preparation of a ~ p~lymer by copolymerilzation of ~ ~;
methacrylic anhydr~do with ethyl~ ~r~l~y
un~aturated monomer~
627 g of methG~y~Lo~yl acetate are ~ to
120~C in a four-necke~ flask fitted with stirrer, ~;
reflux co~en~er, two metering ves~els and thermometer.
~. ~ . ~ ... . ..
A pre-prepared mixture of 10 g of methacrylic anhydride
~1.0%, based on ~olid epoxy resin), 265 g of
methacrylic acid, 375 g of styrene and 409 g of ethyl
acrylate i~ metered in at 120~C at a uniform rate over
a period of two hours from the first metering vessel,
and a solution of 27 g of tert-butyl perbenzoate in
90 g of metho~y~.opyl acetate i~ metered in over a
period of 2.5 hours from the second metering vessel,
both feeds being started ~imultAneo~ly. When the feeds
are complete, the reactor contents are kept at 120~C
for a further four hours.
' ~ A '
~ 21~321i~
- 34 -
4.2 Reaction of the prepolymer w~th epoxy re~
1802 g of the prepolymer mixture from 4.1 are
warmed to 120~C in a four-necked fla~k fitted with
stirrer, reflux condenser and thermometer. 1000 g ~of
solid epoxy resin (Epikote lOD7 having an EEW of
1751 g!mol) are dissolved in portion~ in this mixture,
and the reactants are allowed to react at 120~C for a
further hour and the mixture is then diluted to a
solids content of 70% with 168 g of butyl glycol. The
binder has an acid number of 85.3 mg of X0~/g and a
viscosity of 1.0 dPa 8 (25% strength solution in butyl
glycol, plate-and-cone viscometer at 23~C).
Example 5s Preparation of a~ di~persion of
an anhydride-mod~fied epoxy acrylate
r-~in with sub~tantial blo~ of the
epoY~- fu~ction~ by means of aoetic
acid ~-for th- acrylat~on
5.1 ~y~ '~ of an epoxy re~Ln hav~ng an
equ~val-nt w ight of about 1700
663 g of a liquid epoxy resin based on
bisphenol A and having an epox;~ equivalent weight of
187 g/mol and 111 g of xylene are weighed out into a
four-necke~ flask fitted with stirrer, reflux con~n~er
and ~h9 -ter, and the mixture is heated with
stirring. 337 g of bisphenol A and 0.3 g of ethyl-
triphenylphosphon; iodide (Shell Catalyst 1201) are
added at 100~C. The reaction mixture is heated to
160-165~C. The supply of heat is regulated 80 that the
exoth~ icity which occurs does not allow the
2 1
rr
' ' ' ! .,
- _ 35 _
temperature in the flask to rise above a maximum value
of 180~C. The reaction mixture is kept at 160-165~C
until an epox;~e equivalent weight of 1700 has been
reached, and is then cooled to 140~C.
5.2 ReactJon of th- epoxy re~n from 5.1 wlth an
unsaturated anhydr~d-
1106 g of the epoxy re~in solution from 5.1 areheated to 140~C in a four-necke~ flask fitted with
stirrer, reflux con~en~Pr and thP -ter. 5 g of
methacrylic anhydride (0.50~, based on solid epoxy
resin) are added, and the reactor contents are kept at
140~C for one hour, then cooled to 130~C and diluted
with 63 g of butyl glycol, 63 g of butanol and 13 g of
pentanol mixture.~5 5.3 Réactlon of th- reactlon ~,~a~ ~ fro~ 5.2 wlth
carboxylic acld
1245 g of the reaction product from 5.2 are
warmed to 130~C in a four-necke~ flask fitted with
stirrer, reflux con~e~er and thermometer. 29 g of
acetic acid and 2 g of dimethylbenzylamine are added,
and the reaction mixture i8 kept at 130~C until an EEW
of > 10000 g/mol has been reAche~, is then cooled and
is diluted with 255 g of butyl glycol, 284 g of butanol
and 57 g of pentanol mixture.~5 5.4 Acrylatlon of th- r-actlon ~.~3 ~ a~ ln
5.3
1797 g of the reaction product from 5.3 are
warmed to 120~C in a four-n~cke~ flask fitted with
stirrer, reflux co~n~er, two metering vessels and
- 2 1 ~ 2 1 ~ ~
- 36 - ;~
thermometer. A pre-prepared mixture of 172 g of
methacrylic acid, 113 g of styrene and 124 g of ethyl
acrylate is metered into the reactor contentis at a
uniform rate over a period of two hours from the fir~t
metering vessel. At the same time, a solution of 10 g
of tert-butyl perbenzoate in 29 g of butyl glycol are
added dropwise at a uniform rate over the course of
2.5 hours from the second metering vessel. When the
feeds are complete, the reactor contentR are kept at
120~C for a further three hours. The resultant product
has an acid number of 73 mg of KOH/g and a viscosity of
16.5 dPa 8 (30~ strength ~olution in butyl glycol,
plate-and-cone viscometer, D-cone at 23~C) at a solids
content of 63%. The reaction mixture is adjusted to a
15solid_ content of-55% with 102 g of butyl glycol, 102 g
of butanol and 41 g of pentanol mixture.
5.5 Neutralization of th- reaction ~ from 5.4
2488 g of the reaction product from 5.4 are
warmed to 95~C in a four-nPckP~ flask fitted with
stirrer, reflux co~enRer, metering vessel and
thermometer. 53 g of dimethylethanolamine are metered
into the reactor contents over a period of 15 minutes,
the mixture is then kept at 95~C for a further
20 minutes and then cooled to 80~C. The degree of
neutralization is 30~
'"'''' ~
~: '' ~ 'i' ' ', :;,~;, ' ~ ~ ' ' . '
2 1 ~ 2 ~ i~J~ 6
, - ,,
- 37 -
5.6 Preparation of an a~,s-_s di~per~on of the
react~on product from 5.5
2541 g of the hin~r from 5.5 neutralized by
the process described are run out of the reactor at
80~C into 2230 g of ~- ;neralized water warmed to 60~C,
and are dispersed for one hour. The resultant
dispersion has a solid~ content of 28% and an efflux
time (DIN 4 cup, 23~C) of 61 3econ~
5.7 Preparatlon of an ~nter~ial spray coatlng mat-rlal
for 2-part bev-rage cano u~lng the dl~pers~on
propared a~ in 5.6
83.1 part~ of the aqueous dispersion from 5.6
are adju~ted to a solids content of 25% by means of
2.3 part~ of Luwipal 068 (7%, ba~ed on the solids
content of the dispersion 5.6) and 1.46 parts of
demineralized water. Testing was carried out in 33 cl
steel cans. The cans were ~p,a~ed using the spray-
bake/spray-bake proces~ at a rate of 2 * 180 ~g of
coating material/can. Two different drying procesqe~ at
215 and 225~C are tested for the bAk;ng process. Test~
were carried out for pasteurization and sterilization
stability, porosity, croscl;nk;n~ (MEK te~t),
fle~?;h;l;ty (impact sample; nominal ~ 7 mm) and
contents resistance (CuS04 test).
The above-described b;ndPr shows an extra-
ordinarily good result. In particular, the application
properties should be ~ hAFiized~ due to prono~ln~e~
thixotropy of the dispersion.
... ..... ....................................................................... ... ~ -,
~? .' ~ . ?' .. ,~'~,;i'.. ,~ ~, '. ~ g
-= 213~1~u
38 -
Results:
Te3t Result : :
Pasteurization1: ~
5 Water absorption7 +
Adhesion (crosshatch)6 GT O .~.
Sterilization2:
Water absorption7 ++
10 Adhesion (crosshatch)6 GT O
Porosity3 0.7 mA
MEK te~t4 50 double strokes
Impact 8~ le 5 mm
15 CuS04 test5 OK
pH 6.97
Solids content 24.7%
Vi~cosity 30 8 DIN 4 -:
1 45 minutes at 80~C in ~ ;n~ralized water .
2 60 minutes at 121~C in tap water
3 Cu/Cd solution, 30 8, 4 V
4 l kg weight
10% CuS04, 10% ~~ ing HCl, 80% water, 24 houre
25 6 crosshatch test with peeling off of Tesa film, : -:
best score = GT 0, worst score a GT 5
7 assessment scale from ++ to --
D5
~. 2 1 3 2 1 0 S
- 39 - ~ ~;
Example 6: Preparat~on of an agueou~ di~persion of
a~ anhydr~de~ fied epoYy acrylat~
re~ln wlth ~ubffta~tial blo~ g of the
~ . , - -
epox~e function~ by ~ean~ of acetic
acid ~efore the acrylatio~
6.1 U~y~ ~8 of an epoxy re~in having an EEW of 1700
661 g of a liquid epoxy resin based on
bi~phenol A and having an epo~;~e equivalent weight of
186 g/mol and 111 g of xylene are weighed out into a
,; 10 four-necked flask fitted with ~tirrer, reflux condenser
and thermometer, and are heated with stirring. 339 g of
bisphenol A and 0.5 g of ethyltriphenylphosphonil-m
;o~;~e (Shell Catalyst 1201) are added at 100~C. The
reaction mixture is heated to 160-165~C. The supply of
heat is regulated ~o that the exothermicity which
occurs does not allow the temperature in the fla~k to
rise above a maximum value of 180~C. The reaction
mixture is kept at 160-165~C until a target EEW of 1700
has been reached, and i9 then cooled to 140~C.
6.2 R action of th- ~poxy re~ln from 6.1 with
anhydrid-
1101 g of the epoxy resin solution from 6.1 areheated to 140~C in a four-nec~e~ flask fitted with
~tirrer, reflux conA~nRer and thermometer. 8.5 g of
~o~ecenylsllGcin;c anhydride (0.86%, ba~ed on solid
epoxy resin) are added, and the reactor contents are
kept at 140~C for one hour, then cooled to 130~C ant
diluted with 66 g of butyl glycol, 66 g of butanol ant
13 g of pentanol mixture.
- .'' 2 ~ 3 ~ S
,. . . .
- 40 -
6.3 Rea~tlon of the react~on ~l~d~L from 6.2 with
carboxylic ac~d
1254 g of the reaction product from 6.2 are
warmed to 130~C in a four-necked flask fitted with
stirrer, reflux co~n~er and ths ~er. 29 g of
acetic acid and 2 g of dimethylbenzylamlne are added,
and the reaction mixture is kept at 130~C until an EEW
of ~ 12000 g/mol has been re~ch~, then cooled and
diluted with 286 g of butyl glycol, 323 g of butanol
and 65 g of pentanol mixture.
6.4 Acrylation of th- rea¢tlon ~ from 6.3
1928 g of the reaction product from 6.3 are
warmed to 120~C in a four-necke~ flask fitted with
stirrer, reflux co~e~qsr, two metering vessels and
thermometer. A ~,e ple~ared mixture of 192 g of
methacrylic acid, 156 g of ~tyrene and 170 g of ethyl
acrylate is metered into the reactor contents at a
uniform rate over a period of two hours from the first
metering vessel. At the same time, a solution of 12 g
of tert-butyl perbenzoate in 37 g of butyl glycol are
added dropwise at a uniform rate over the course of
2.5 hours from the second metering vessel. When the
feeds are complete, the reactor contents are kept at
120~C for a further three hours. The resultant product
has an acid number of 80 mg of KOH/g and a viscosity of
7.3 dPa 8 (30% strength solution in butyl glycol,
plate-and-cone visc~ -ter, C-cone at 23~C) at a solid~
content of 63%.
~,~,~'.,, ,,~,~ ,~i"~
2~321i3 ~
: - "
- 41 -
6.5 Neutra1ization of the reaction produ~t from 6.4
1520 g of the reaction product from 6.4 are
warmed to 90~C in a four-necked flask fitted with
stirrer, reflux Co~n~ter~ metering vessel and
thermometer. A mixture of 37 g of dimethylethanol~ ;ne
and 79 g of ~ ineralized water is metered into the
reactor content~ over a period of 15 minutes, the
mixture is then kept at 90~C for a further 20 minutes,
and 144 9 of solid epoxy resin ba~ed on bisphenol A and
having an ep~Yi~e eguivalent weight of 1700 g/mol are
then added to the neutralized h; nA~r and ~tirred in for
80 minutes until a uniform solution has formed. The
degree of neutralization i~ 30%.
6.6 Preparat~on of an -,.P~_~ di~iper~i~on of the
react~on ~ from 6.5
2187 g of demineralized water are added at 90~C
over a period of 60 minute~ to 1780 g of the binder
mixture from 6.5 neutralized by the process de~cribed,
and are dispersed with stirring. Dispersal is then
cont;nue~ at 90~C for a further hour, and the mixture
is then cooled. The re~ultant dispersion has a ~olids
content of 27% and an efflux time (DIN 4 cup, 23~C) of
14 secon~c.
2~32~
~., .
- 42 -
Example 7: Preparation of an aqu~ou~ d~sper~ion o$
an anhydride-~odified epoxy acrylate
r0~in with sub~tantial bloc~ n~ of the
epoYI~ function~ by mean~ of acet~c
acid before th~ acrylation
7.1 Upgrade of an epoxy res~n hav~ng an EEW of 1700
661 g of a liquid epoxy re~in based on
bisphenol A and having an epoxide equivalent weight of
186 g/mol and 111 g of xylene are weighed out into a
four-necke~ flask fitted with stirrer, reflux co~de~er
and thermometer, and are heated with stirring. 339 g of
bisphenol A and 0.25 g of ethyltriphenylphosphonium
iodide (Shell Catalyst 1201) are added at 100~C. The
reaction mixture is heated to 160-165~C. The ~upply of
heat is regulated 80 that the exothermicity which
, ;. .:. . ~. ..
occurs doe~ not allow the temperature in the flask to
rise above a maximum value of 180~C. The reaction
mixture is kept at 160-165~C until a target EEW of 1700
has been re~he~, and is then cooled to 140~C.
7.2 R a¢tion of th- epoxy resin fro~ 7.1 w~th
,id-
1100 g of the epoxy resin solution from 7.1 areheated to 140~C in a four-necke~ flask fitted with
stirrer, reflux co~n~er and thermometer. 8.5 g of
~o~cenylsuccinic anhydride (0.86%, based on solid
epoxy resin) are added, and the reactor contents ar~
: -
kept at 140~C for one hour, then cooled to 130~C and
diluted with 66 g of butyl glycol, 66 g of butanol and '~
13 g of pentanol mixture.
~ ,".,,s,~,"".s~
21~2~ 3 s
;i . '.
! ' _ 43 _
7.3 React~on of the reaction product from 7.2 with
car~oxylic acid
1254 g of the reaction product from 7.2 arewarmed to 130~C in a four-necked flask fitted with
stirrer, reflux con~n~er and thermometer. 29 g of
acetic acid and 2 g of dimethylbenzylamine are added,
and the reaction mixture is kept at 130~C until an EEW
of ~ 9000 g/mol has been re~che~ ~ i8 then cooled and
is diluted with 287 g of butyl glycol, 324 g of butanol
and 65 g of pentanol mixture.
7.4 Acrylat~on o~ the reaction p~.d ~ from 7.3
1935 g of the reaction product from 7.3 are
warmed to 120~C in a four-nec~e~ flask fitted with ~ ~ '
stirrer, reflux con~enqer, two metering vessels and
lS thermometer. A pre-prepared mixture of 193 g of ~ m
methacrylic acid, 157 g of styrene and 171 g of ethyl
.
acrylate is metered into the reactor contents at a
uniform rate over a period of two hours from the fir~t
metering vessel. At the same time, a ~olution of 12 g
of tert-butyl perbe~70ate in 37 g of butyl glycol is
added dropwise at a uniform rate over the cour~e of
2.5 hours from the second metering vessel. When the
feed~ are complete, the reactor contents are kept at
120~C for a further three hour~. The resultant ~LGdu~
has an acid number of 80 mg of K0~/g and a viscosity of
8.0 dPa 8 (30% strength solution in butyl glycol,
plate-and-cone viscometer, C-cone at 23~C) at a solids
content of 63%.
.5~ , ~ ., . - ., ,
2 1 3 ~
- 44 -
7.5 Neutralization of th- react~on p~od~L from 7.4
1416 g of the reaction product from 7.4 are
warmed to 90~C in a four-nec~l flask fitted with
~tirrer, reflux condenser, metering vessel and
thermometer. A mixture of 34 g of dimethylethanolamine
and 73 g of ~ ineralized water is metered into the
reactor contents over a period of 15 minutes, the
mixture is then kept at 90~C for a further 20 minutes,
and 134 g of solid epoxy resin baeed on bisphenol A and
having an ep~Y;~ equivalent weight of 1700 g~mol are
then added to the neutralized bin~er and stirred in for
:. :.. ..
90 minutes until a uniform solution has formed. The
degree of neutralization is 30%.
7.6 Preparation of an ~ o tl~ r~ion of the
reaction product from 7.5
2038 g of demineralized water are added at 90~C
over a period of 60 minute~ to 1658 g of the ~;n~r
mixture from 7.5 neutralized by the procecs described,
and are dispersed with stirring. Disper~al is then
cont;nued at 90~C for one hour, and the mixture is then
cooled. The resultant dispersion has a solids content
of 27% and an efflux time (DIN 4 cup, 23~C) of
14 seco~R.
2 1 c3 ~
, ..................................................................... .
. . .
- 45 -
Example 8: Preparation of an aqueous di~per~ion of
an anhydr~ ';fied epoxy res~n with
part~al hJoc~ of the apoYi d~ fun~tion
by mean~ of benzo~c acid before the
acrylation ~ ~
8.1 Upgrade of an epoxy re~n havlng an equi~alent :.<.. 0
welght of about 1700
661 g of a liquid epoxy resin based on
bisphenol A and having an epo~;~e equivalent weight of
186 g/mol and 111 g of xylene are weighed out into a
four-necke~ flask fitted with stirrer, reflux co~d~n~er
and thermometer, and are heated with stirring. 339 g of .
bisphenol A and 0.3 g of ethyltriphenylphosrhs~;um
iodide (Shell Cataly3t 1201) are added at 115~C. The
reaction mixture is heated to 160-165~C. The supply of
heat i~ regulated 80 that the exothermicity which
occurs does not allow the temperature in the flask to -~.
rise above a maximum value of 180~C. The reaction -
mixture is kept at 160-165~C until an epnY;~
equivalent weight of 1700 has been reAche~, and is then
cooled to 140~C. -~
8.2 ~eaction of th- epoxy re~in fro~ 8.1 wlth an ~-
un~aturated anhydr~d- :~
1100 g of the epoxy resin solution from 8.1 are
heated to 140~C in a four-neck~ flask fitted with
stirrer, reflux condenser and the ~er. 2.5 g of
methacrylic anhydride (0.25%, based on solid epoxy
resin) are added, and the reactor contents are kept at
140~C for one hour, then cooled to 130~C and diluted
?l~?~q'~
:
- 46 -
with 68 g of butyl glycol, 68 g of butanol and 14 g of
pentanol mixture.
8.3 Reaction of the reactlon ~ixture from 8.2 w~th
carboxylic acid using a pho~phorus catalyet
1252 g of the reaction mixture from 8.2 are
warmed to 130~C in a four-nec~e~ flask fitted with
stirrer, reflux co~nser and the -ter. 46 g of
benzoic acid and 0.5 g of ethyltriphenylphosphonium
;o~ (Shell Catalyst 1201) are added, and the
reaction mixture i8 kept at 130~C until an EEW of
5000 g/mol has been re~he~, is then cooled and is
diluted with 304 g of butyl glycol, 273 g of butanol
and 61 g of pentanol mixture.
8.4 Acrrlatilon of th- roactilon ~ ucL pr-pared a- ln
8.3
1899 g of the reaction mixture from 8.3 are
warmed to 120~C in a four-neck~ flask fittet with
stirrer, reflux con~n~er, two metering ves~els and
thermometer. A pre-prepared mixture of 184 g of
methacrylic acid, 120 g of styrene and 131 g of ethyl
acrylate is metered into the reactor contents at a
uniform rate over a period of two hours from the first
metering vessel. At the ~ame time, a solution of 10 g
of tert-butyl perbenzoate in 31 g of butanol is added
dropwise at a uniform rate over the course of 2.5 hour~
from the second metering vessel. When the feeds are
complete, the reactor contents are kept at 120~C for a
further three hours. The resultant product has an acid
n~ '?r of 86 mg of KOH/g and a viscosity of 9.4 dPa 8
,, , ~ ' ' ;t i ~' -
~ ~"~ ".t~
2~213',3
.i
_ 47 _
(30% strength) solution in butyl glycol, plate-and-cone
viscometer, D-cone at 23~C) at a solids content of 62%.
8.5 Neutralizat~on of the reaction product from 8.4
2274 g of the reaction mixture from 8.4 are
warmed to 90~C in a four-neck~ fla~k fitted with
stirrer, reflux condenser, metering vessel and
thermometer. A solution of 55 g of dimethylethanolamine
in 248 g of demineralized water is metered into the
reactor contents over a period of 15 minutes, the
mixture is then kept at 95~C for a further 30 minutes,
and then cooled to 80~C. The degree of neutralization
is 30%
8.6 ~e~ration of an ?~ P~ ~ d~p-rslon of the
r-actlon p~ 8.5
2577 g of the b;n~sr from 8.5 neutralized by
the proces~ described are run out of the reactor at
80~C into 2560 g of demineralized water warmed to 60~C
and are dispersed over a period of one hour. The
resultant dispersion has a solids content of 28% and an
efflux time ~DIN 4 cup, 20~C) of 30 ~ec
8.7 Preparation of variou~ cro~ n~1 v~r~ for
LU~ cap~ (twi~t-off cap~) u~ng th- di~per~ion
from 8.6
The dispersion prepared as in 8.6 is tested)
with the following crossl ;nking agents in two different
ratios (95:5 and 85:15):
Cymel 1123 (American Cyanamid)
Luwipal B017 (BASF AG)
, ...*
De~ - lr BL 3175 (Bayer AG)
2~32~i~i) ;
- 48 -
Tests were carried out for the fl~yihility on
club cans, the sterilization ~tability (1 hour, 130~C)
and the gloss in a system with a white paint.
For each inte -';Ate stage of the overall
hAk;ng procegs, the fle~;hil;ty is assessed separately,
i.e. without high-bake (bAk;ng proce3s for varn;shes)~
with high-bake (bAk;ng process for primers) and without
or with bAk;ng for a compound material. Sterilization
is assessed without and with high-bake.
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