Note: Descriptions are shown in the official language in which they were submitted.
iO~ 91
This invention relates to a stable water-dispersible composition
of matter comprising a blend of (A) from about 15% to about 85%, by weight,
of a non-ionic polyether polyol resin having only carbon, hydrogen and oxygen
atoms and optionally a halogen atom, having an average molecular weight
between about 300 and 4,000, having at least two alcoholic hydroxy groups
and not less than about 20%, by weight, of hydrophobic moieties derived at
least in part from aromatic or cycloaliphatic materials and correspondingly
not more than about 80%, by weight, of hydrophilic moieties consisting of'
-(CH2CH2-0-) units; (B) correspondingly from about 85% to about 15%, by
weight, of a water-dispersible, non-gelled, anionic vinyl polymer having a
molecular weight between about 5,000 and 100,000 and having pendant carboxyl
groups, in an amount ranging between about 0.40 gram mol to 4.00 gram mols
per 1,000 grams of polymer; and (C) from about 10% to about 50%, by weight,
based on the total weight of (A) and (B) of a compatible aminoplast cross-
linking agent having an average molecular weight not greater than about 1,500,
wherein said vinyl polymer is prepared in bulk or solution polymerization.
The present invention is in the field of polymeric materials
that are particularly useful in the coating field as well as in the manufac-
ture of low pressure laminates, adhesives, molding compositions, and textile
treating resins. The compositions of the present invention can be used to
apply a film to the surface of an existing paper web from dispersions or
solutions of the compositions of the present invention. These blends can also
be utilized to impregnate paper sheets for use in the manufacture of decora-
tive laminates.
Blends of resinous materials have been manufactured and sold for
a substantial plurality of years for a number of different purposes. Many of
these blends of resinous materials have been utilized to a great extent in
the coating resin art. In the earlier days, these coating compositions were
dispersed or dissolved in organic solvents and upon application, the solvent
was evaporated into the atmosphere. Efforts
.~
-- 1 --
~j
~06S99~.
1 have been made more recently, because of ecologlcal consid-
erations, to utilize coating compositions which were dispers-
ed in an aqueous medium or were applied as neat resins and
cross-linked without the evaporation of any solvent. ~lany
5 of these compositions of matter are generally composed of ~,
blends of reactive linear polymeric materials which have the
capability of being cross-linked because of reactive sites
pendant along the linear polymeric material and when these
materials are cross-linked, they are converted to the ther~o-
set state by the use of selected cross-linking agents. In
the cross-linked state, the film is in a thermoset condition
whereas before the cross-linking, the materials are poten-
tially thermosetting.
The compositions of the present invention are com-
posed of three (3) essential components. The first component
is a non-ionic polyether polyol resin having an average mo-
lecular weight between about 300 and 4,000, having at least
two alcoholic hydroxy groups and not less than about 20%,
by weight, of hydrophobic moieties derived at least in part
from aromatic or cycloaliphatic materials and correspondingly
not more than about 80%, by weight, of hydrophilic moieties
consisting of -(CH2CH2-O-) units which may be derived Erom
ethylene oxide~
These polyols may be prepared, for instance, by
reacting a compound containing a plurality of hydroxy groups
with an alkylene oxide. These hydroxy groups may be either
alcoholic hydroxy groups wherein the OH group is attached
directly to a carbon atom in a cycloaliphatic chain or these
hydroxy groups may be phenolic hydroxy groups wherein the -OH
group is attached directly to an atoring. In other words,
these compounds containing a plurality of hydroxy groups, may
be aromatic or cycloaliphatic compounds or materials. These
polyhydric compounds may be monomeric or part of a low molec-
~0655~91
1 ular weight polymer chain such as a polymer or a phenol-for-
maldehyde reaction product, many of which are well known
such as the novalak resin type. Among the monomeric compounds
that can be used to make the polyether polyol resin used in
the present invention are the bisphenol compounds such as
bisphenol A which is identified as 4,4'-isopropylidene di-
phenol which is also known as 4,4'-dihydroxydiphenyldimethyl-
methane. Another bisphenol is identified as bisphenol F which
is 4,4'-methylenediphenol which is also known as 4,4'-dihyL
droxydiphenylmethane. Other polyhydric phenols which can be
used in preparing the non-ionic polyether polyol resins used
in the present invention are the dihydric phenols represented
by the general formula:
lS NO ~ _ C - ~ ~
wherein the phenolic hydroxy groups may be in one of the 2,2';
2,3'; 2,4'; 3,3'; 3,4'; or 4,4' positions on the aromatic
nuclei, and each of R and Rl represent hydrogen, an alkyl
group, such as methyl, ethyl, propyl, isopropyl, butyl, sec-
-butyl, pentyl, isopentyl, hexyl, isohexyl, and the like; a
cyclo(lower)-alkyl group, such as cyclohexyl or substituted
cyclohexyl group, e.g., methyl-, ethyl-, propyl-, butyl-,
pentyl-, and hexyl-substituted cyclohexyl, or an aromatic
group, such as phenyl, tolyl, xylyl, and the like. In addi-
tion, the phenolic rings may have other substituents in ad-
dition to the hydroxyl group, for example, lower alkyl groups
containing from 1 to 4 carbon atoms, i.e., methyl, ethyl,
propyl, isopropyl, butyl, sec-butyl, and tert-butyl groups,
halogen atoms, i.e., fluorine, chlorine, bromide or iodine,
and the like. It can be seen from this that these polyether
polyol resins will contain only carbon, hydrogen and oxygen
~06S5~91
l atoms and optionally one or more halogen atoms.
An illustrative, but by no means exhaustive, list-
ing of dihydric phenols falling within this general formula
includes 4,4'-dihydroxydiphenyldimethylmethane ~bisphenol A),
2,4'-dihydroxydiphenylethylmethane, 3l3'-dihydroxydiphenyl-
diethylmethane, 3,4'-dihydroxydiphenylmethylpropylmethane,
2,3'-dihydroxydiphenylethylphenylmethane, 4,4'-dihydroxyd-
iphenylpropylphenylmethane, 4,4'-dihydroxydiphenylbutylphenyl-
methane, 2,2'-dihydroxydiphenylditolylmethane, 4,4'-dihydroxy-
diphenyltolylmethylmethane, and the like.
In addition to these aromatic compounds, it is pos-
sible to use such cycloaliphatic diols as cyclohexane dimeth-
anol, 4,4'-isopropylidene dicyclohexanol, tricyclo[4.].1.0 ' ]
decane-4,8-dimethanol and 4,4'-dihydroxy dicyclohexyl methane.
Other polyhydric cyclo aliphatic compounds are the lower al-
kyl derivatives of the above compounds which contain one or
more Cl-C4 substituents.
Among the alkylene oxides what may be reacted with
the polyhydric compounds such as those set forth hereinabove
are ethylene oxide, propylene oxide, butylene oxide and ole-
fin oxides with a chain length of C5-C18, styrene oxide, 4-
-oxatetracyclo-(6.2.1.02'7, 03'5) undecan-9(10)-ol and simi-
lar mono epoxy compounds derived from aliphatic, cycloaliphatic
and aromatic hydrocarbons. With the exception of ethylene
oxide, all other alkylene oxide compounds impart hydrophobic
moieties to the polyol.
The expression "derived at least in part from aro-
matic or cycloaliphatic materials", as used herein, signifies
that there must be present in these polyol resins aromatic
or cycloaliphatic hydrophobic moieties but additionally there
may, and in most instances, there will be other hydrophobic
acyclicaliphatic moieties. For instance, when bisphenol A
is used to make a polyol resin, there will be aromatic moiet-
-- 4 --
1~5~9~
ies from the bisphenol A but there also will be an isopropylidene hydrophobicmoiety position between the two aromatic rings. By the same token, when
hydrogenated bisphenol A is used, there will be cycloaliphatic moieties de-
rived from the cyclohexane rings but additionally there will be an isopropyl-
idene hydrophobic moiety between each pair of cyclohexane rings.
As preferred polyether polyols there are mentioned the reaction
product of 4,4'-methylene diphenol and ethylene oxide, the reaction product
of 4,4~-methylene diphenol and propylene oxide and the reaction product of a
phenol-formaldehyde resin and propylene oxide.
In order that the non-ionic polyether polyol resins used in the
present invention may be more completely identified, the following examples
are set forth in which all parts are parts by weight unless otherwise indi-
cated. These examples are set forth primarily for the purpose of illustration
and any specific enumeration of detail contained therein should not be inter-
preted as a limitation on the case except as is indicated in the appended
claims. In these examples, certain polyethers are disclosed which are commer-
cially available. These polyethers are made by the method shown with the
reactants illustrated and have the properties set forth hereinbelow.
Polyether A is prepared by reacting 1 mol of bisphenol F (4~4~-
methylene diphenol) with 2 mols of propylene oxide. The reaction product
thus produced is then reacted with 7 mols of ethylene oxide. The resulting
product has a viscosity of 1650 centipoises and a hydroxyl number of 225.
The molecular weight of the product is about S00. This product has about
49% hydrophilic moieties and about 51% hydrophobic moieties. Polyether A is
a liquid.
Polyether B is prepared by reacting 3 mols of phenol under acidic
~ - 5 -
~C
~ . .
lU6SS~9~
conditions with 2 mols of formaldehyde. The resulting product is then react-
ed with 9 mols of ethylene oxide. The resulting polyether has a viscosity of
11,700 centipoises, a hydroxyl number of 244 and a functionality of 3. Poly-
ether B has a molecular weight of about 680. This
- 5a -
.~.
10659gl
1 product has about 56% hydrophilic moieties and about 44% hy-
drophobic moieties. Polyether B is a liquid.
Polyether C is prepared by reacting 1 mol of the
phenol formaldehyde reaction product of polyether B in se-
quence with 3 mols of ethylene oxide and then with 3 mols ofpropylene oxide. The resulting polyether has a viscosity of
132,000 centipoises and a hydroxyl number of 291. The molec-
ular weight is about 570. This product has about 22~ of hy-
drophilic moieties and about 78% hydrophobic moieties. Poly-
ether C is a liquid.
Polyether D is prepared by reacting 1 mol of bis-
phenol A (4,4'-isopropylidene diphenol) with 6 mols of ethyl-
ene oxide. The resulting product has a viscosity of 2,840
centipoises and a hydroxyl number of 215. The molecular weight
of polyether D is about 520. This product has about 54% hy-
drophilic moieties and about 46% hydrophobic moieties. Poly-
ether D is a liquid.
Polyether E is prepared by reacting 1 mol of bis-
phenol A with 6 mols of propylene oxide. The resulting prod-
uct has a viscosity of 8120 centipoises and a hydroxyl numberof 199. Ihe molecular welght of the polyether E is about
565. This product has about 0% hydrophilic moieties and about
100~ hydrophobic moieties. Polyether E is a liquid.
Polyether F is prepared by reacting 1 mol of hydro-
genated bisphenol A with 10 mols of ethylene oxide. The prod-
uct has a molecular weight of 601, a hydroxyl number of 158
and is a solid. The polyether contains about 65% hydrophilic
moieties and 35% hydrophobic moieties.
Polyether G is prepared by reacting 1 mol of bis-
phenol A with 10 mols of ethylene oxide to produce a liquidproduct having a molecular weight of 679. The hydroxyl num-
ber is 154. Polyether F contains about 66% of hydrophilic
groups and 34% of hydrophobic groups.
~06599~
1 Polyether H is prepared by reacting 1 mol of bis-
phenol A with about 21 mols of ethylene oxide to produce a
waxy solid having a molecular weight of about 1150 and an
hydroxyl number of 98. The polyether contains about 80% of
hydrophilic groups and about 20% of hydrophobic groups. This
polyether is soluble in water.
Polyether I is prepared by reacting 1 mol of Poly-
ether F with 12.5 mols of ethylene oxide to produce a hard
waxy solid having a molecular weight of 1300, an hydroxyl ~um-
ber of 88, and contains about 80% of hydrophilic ethyleneoxide moieties and about 20% hydrophobic moieties.
Polyether J is prepared by reacting 1 mol of bis-
phenol A with 10 mols of propylene oxide. The resulting prod-
uct has a hydroxyl number of 140 and molecular weight about
770. This product has 0% hydrophilic moieties and 100~ hy-
drophobic moieties. This polyether is normally liquid.
Polyether K is prepared by reacting 1 mol of bis-
phenol A with 6 mols of propylene oxide and 2 mols of ethyl-
ene oxide. The resulting product has a hydroxyl number of
169 and molecular weight about 664. This product has 13.7%
hydrophilic moieties and 86.3% hydrophobic moieties. ThiS
polyether is normally li~uid.
Polyether L is prepared by reacting 1 mol of bis-
phenol A with 6 mols of propylene oxide and 12 mols of ethyl-
ene oxide. The resulting product has a hydroxyl number of100 and molecular weight about 1140. This product has 47.8%
hydrophilic moieties and 52.2% hydrophobic moieties. This
polyether is normally liquid.
The amount of the non-ionic polyether polyol resin
used as component (A) in the composition of the present inven-
tion may be varied between about 15% to about 85%, by weight,
based on the total weight of the polyether polyol resin and
the non-gelled anionic vinyl polymer material having the pend-
- 1065S~9~
1 ant carboxyl groups. The amount of (B), the non-gelled an-
ionic vinyl polymeric material, used with the polyether polyol
resin is correspondingly from about 85% to about 15%, by i
weight, on the total weight of (A) and (B). The proportions
of (A) and (B) to be used are dependent upon a number of fac-
tors. These include the hydrophobic/hydrophilic balance of
the components and the use of the coating. For example, if
a very hydrophobic polyether polyol is to be used, i.e. one
with a high ratio of hydrocarbon moieties to ethylenoxy
groups, it is desirable to use a larger proportion of the
non-gelled, anionic polymer. Since one of the functions of
the vinyl polymer is to serve as a dispersing agent for the ~
polyether polyol, more is needed with a more hydrophobic poly-
ol. On the other hand, if a more hydrophilic polyol is being
used, it would be normal to use a smaller proportion of the
anionic, non-gelled vinyl polymer. It will be understood
that a considerable range of proportions is possible with
pairs of polyol and vinyl polymer components, but not every
set of proportions is suitable with every pair. With respect
to the final coating properties, the vinyl polymer generally
improves the chemical resistance properties of the coating
and makes it easier to apply; the polyether polyol on the
other hand improves the flexibility of the coating, increases
the application solids achievable and reduces the amount of
neutralizing amine required. Thus, a formulator skilled in
the art may prepare coatings with a range of properties by
varying the proportions of the components according to the
above considerations. Whatever the percentages used, the
total percentages of (A) and (B) will be 100%.
The second essential component in the composition
of the present invention is a water-dispersible non-gelled
anionic vinyl polymeric material prepared by polymerizing at
least some a,~-ethylenically unsaturated carboxylic acid with
-- 8
lO~S~91
l other polymerizable vinyl monomers of the acrylic or non-
-acrylic types wherein the a,~-ethylenically unsaturated car-
boxylic acid is used in amounts sufficient to provide pendant
carboxyl groups in the polymer in an amount ranging between
about 0.40 mol to 4.00 mols per thousand grams of polymer.
These vinyl polymers having pendant carboxyl groups will have
an average molecular weight varying between about 5,000 and
100,000. The amount of the vinyl polymer used will in some
instances vary inversely with the molecular weight. When
the molecular weight is about 100,000 the amount used should
be 15% or an amount closer to the lower limit than the upper
limit of 85~. On the other hand when the molecular weight
of the vinyl polymer is low, such as around 5,000, the amount
used can cover the entire range of weight percentages. These
water-dispersible non-gelled anionic vinyl polymeric materials
can be prepared by polymerizing for instance an a,~-ethylen-
ically unsaturated mono or polycarboxylic acid and an alkyl
ester of a,~-ethylenically unsaturated monocarboxylic acid
with or without any further modifying polymerizable acrylic
or non-acrylic monomer. These water-dispersible non-gelled
anionic vinyl polymers may be simple copolymers or they may
be terpolymers or tetrapolymers of higher polymer components
in which an additional acrylic or non-acrylic monomer is ut-
ilized. When only the a,~-ethylenically unsaturated type
acid monomer and the acrylic type ester monomer are used to
form a copolymer, one would generally use a sufficient amount
of the acidic material so as to provide in the ultimate vinyl
polymer pendant carboxyl groups in an amount ranging between
about 0.40 gram mol to about 4.00 gram mols per 1,000 grams
of polymer.
The term "water-dispersible" as used herein applies
to both true and micellar solutions as well as dispersions in
which the polymer is only suspended in the aqueous medium.
1065991
1 The polyols used in the compositions of the present
invention should be substantially free of any reactive groups
that would interfere with the in situ polymerization of the
polymerizable monomers. Reactive groups such as epoxy groups,
episulfide groups and the like will interfere with the poly-
merization by causing premature cross-linking and/or premature
gellation.
All of these anionic water-dispersible non-gelled
polymeric materials will have pendant reactive carboxyl gr~ups
but additionally may or may not have pendant reactive alco-
holic hydroxy groups and/or pendant reactive amide groups.
The water-dispersibility of the polymeric material is achieved
by full or partial neutralization of the ionizable carboxyl
groups pendant from the chain. In addition, the carboxyl
groups provide sites which are reactive with cross-linking
agents. Since a smaller number of groups are required for
dispersibility than for effective cross-linking of the poly-
mer, polymers which contain hydroxy or amide reactive sites
will normally have fewer carboxyl groups than those which
have only carboxyl groups as the reactive sites. All three
of these classes of groups are water-sensitive sites and these
water-sensitive sites should be tied up in inter-reaction
with a cross-linking agent in a cross-linking mechanism. Be-
fore the cross-linking takes place, the cross-linking agent
will function as a plasticizer for the total composition.
The anionic polymeric materials prepared by vinyl
polymerization may be prepared separately by either solution
or bulk polymerization, both of which procedures are thoroughly
well known in the art, and therefore, it is not deemed neces-
sary to elaborate upon such procedures here. Additionally,these vinyl monomers may be polymerized in the presence of
the non-ionic polyether polyol resin with or without benefit
of any other diluent, depending upon whether the polyol resin
-- 10 --
` ~06~99~.
1 is normally liquid or a solid, since these vinyl monomers
are for the most part soluble in these polyether polyol res-
ins or vice versa. The in situ polymerization technique pro-
vides a very convenient way to prepare the compositions of
the present invention. In the polymerization, the polyol
acts as a solvent for the acrylic polymer; however, when the
composition is later formulated into a coating, the polyol
becomes a reactive functional material rather than a volatile
inert solvent. Thus a coating with greatly reduced pollution
potential is obtained. The polymerization reaction in situ
would be carried out under conventional polymerization condi-
tions, namely by feeding the blend of vinyl monomers into the
polyether polyol at a temperature of between about 60~C. and
180C. in the presence of a polymerization catalyst such as
a peroxide catalyst, all of which is well known in the art.
The in situ polymerization of the acrylic monomer
blend in the polyether polyol may result in grafting of the
acrylic polymer onto the polyether polyol. Thus, the final
composition in the in situ polymerization may contain some
molecules in which vinyl polymer is grafted onto the poly-
ether polyol.
If the non-gelled anionic vinyl polymer is prepared
by polymerization in situ in the non-ionic polyether polyol
resin, the compatible aminoplast cross-linking agent can be
added thereto in the selected amounts. On the other hand,
if the anionic vinyl polymer is separately prepared, it may
be added to the polyether polyol resin and then the amino-
plast cross-linking agent added thereto or the polyether polyol
resin may be added to the aminoplast cross-linking agent fol-
lowed by the addition of the anionic vinyl polymer. Alterna-
tively, the anionic vinyl polymer may be added to the amino-
plast cross-linking agent followed by the addition of the
polyether polyol resin or one may introduce all three com-
` 10655~9~
1 ponents into a suitable mixing vessel thus making the totalblend of the three components simultaneously.
It is possible to prepare the compositions of the
present invention by mixing a solution of the acrylic polymer
with the polyol; such a composition can be used to prepare
high performance coatings similar to those available from
the in situ polymerization. Further, a composition free of
organic solvent could be prepared either by distilling the
solvent from the above composition or by dissolving a solid
acrylic polymer in polyol. Although each of these methods
gives rise to compositions useful for formulating coatings,
the direct polymerization of the vinyl monomers in the polyol
is the preferred method of preparation because it is the simp-
lest and most economical method of manufacture.
The vinyl polymers may be prepared by polymerizing
acidic polymerizable monomers such as acrylic acid, methacrylic
acid, crotonic acid, cinnamic acid, ~-benzoyl acrylic acid,
and polycarboxylic acids of the a,~-ethylenically unsaturated
class such as maleic, fumaric, itaconic, mesaconic, aconitic,
and the halogenated acids such as halogenated maleic or more
specificatlly, chloromaleic acid, and the like. These acidic
materials may be copolymerized or polymerized with other mono-
mers which contain no carboxyl groups such as methyl acrylate,
ethyl acrylate, propyl acrylate, butyl acrylate, decyl acryl-
ate, lauryl acrylate, methyl methacrylate, ethyl methacrylate,butyl methacrylate, heptyl methacrylate, decyl methacrylate,
propyl crotonate, butyl crotonate, nonyl crotonate, and the
like.
If desired, one can modify the basic copolymer of
the present invention by copolymerizing therewith one or more
different polymerizable monomers but the amount of these dif-
ferent monomers, depending on their characteristics should
not be so great as to detract from the anionic characteristics
- 12 -
~()65S~91
f
1 of the acrylic polymeric material. In this connection one
could use such polymerizable compounds as styrene, ortho-,
meta or paraalkyl styrenes such as the o-, m-, or p-methyl,
ethyl, propyl, and butyl styrenes, 2,4-dimethyl styrene, 2,3-
-dimethyl styrene, 2,5-dimethyl styrene, vinyl naphthalene,
acrylonitrile, methacrylonitrile, halo ring, or side chain
styrenes such as a-chloro styrene, ortho-, meta or para-
-chlorostyrenes, 2,4-dichlorostyrene, 2,3-dichlorostyrene,
2,5-dichlorostyrene, or the alkyl side chain styrenes such'
as a-methyl styrene, a-ethyl styrene, and the like. Addition-
ally, one can make use of such polymerizable vinyl monomers
as acrylamide, methacrylamide, ethacrylamide, N-tertiarybutyl-
acrylamide, and the like.
If it is desired to incorporate polymerizable mon-
omer moieties containing an alcoholic hydroxy group into the
basic copolymer chain one can produce an anionic polymeric
material of this description by polymerizing the a,~-ethyl-
enically unsaturated carboxylic acid and the alkyl ester of
~ -ethylenically unsaturated carboxylic acid with a polymer-
izable vinyl monomer which contains an alcoholic hydroxy groupsuch as the hydroxyl alkyl esters o~ a,~-ethylenically un-
saturated monocarboxylic acid such as the hydroxy alkyl est-
ers of acrylic acid, methacrylic, ethacrylic acids and chloro
as well as the other halo-substituted acrylic acids. These
esters may either have a primary or a secondary hydroxyl group.
Illustrative of the types of compounds that may be used as
comonomers in preparing the anionic, polymeric material are
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxy-
propyl acrylate, 2-hydroxybutyl acrylate, 8-hydroxyoctyl ac-
rylate, 2-hydroxyethylmethacrylate, 5-hydroxyhexylmethacrylate,
6-hydroxyoctylmethacrylate, 8-hydroxyoctylmethacrylate, 10-
hydroxydecylmethacrylate, 3-hydroxypropyl crotonate, 4-hy-
droxyamyl crotonate, 5-hydroxyamyl crotonate, 6-hydroxyhexyl
106599~
1 crotonate, 7-hydroxyheptyl crotonate, 10-hydroxydecyl croton-
ate, and the like. These hydroxy esters may be used either
singly or in combination with one another with other polymer-
izable vinyl monomers devoid of any alcoholic hydroxy group
including those set forth hereinabove in the discussion of
the carboxyl group containing monomers. Additionally, one
can make use of other hydroxyl-containing polymerizable vinyl
monomers such as methylolacrylamide, methylolmethacrylamide,
and the like.
The compositions of the present invention are par-
ticularly useful as coating compositions and are outstand-
ingly attractive for this purpose since they can be used
without any organic solvent, which when used, may tend to
pollute the atmosphere upon the evaporation of the organic
solvent from the coating. When applied to a substrate such
as an iron phosphated steel panel by spraying and thereafter
baking, the three essential components react with one another
to form a thermoset or cross-linked coating on the substrate.
Because the blend of these components in the presence of a
small amount of base is frequently water-soluble and almost
invariable water-dispersible, these compositions can be di-
luted with water to any selected solids content. If a clear
coating is desired, the blend of the three essential compon-
ents reduced to application solids with water can be used.
However, pigmented coatings can be prepared by the use of
conventional commercially available pigments such as titanium
dioxide, iron oxide red pigment and the like. These composi-
tions are useful as coating compositions for metal, wood,
plastics, textiles, paper, glass, and the like. These compo-
sitions can be applied by spraying, dipping, roller coatingor brushing techniques, and the like.
The rate of cure of the coatings of the present
invention may be increased by addition of acid catalyst. For
- 14 -
1l)6SS~9~
1 this purpose, there may be used any of the conventional acid
catalysts for organic coatings such as p-toluene sulfonic
acid, dodecyl benzene sulfonic acid, phosphoric acid, and
the like. Where acid catalysts are used, best stability of
the coating is achieved by adding sufficient amine to neutral-
ize the catalyst. Since levels of acid catalyst are general-
ly low, this usually requires only a small increase in the
amount of amine.
When the selected polyether polyol resins, the com-
patible alkylated aminoplast cross-linking agent and water-
dispersible non-gelled anionic polymeric material are used
together, stable water-dilutable systems can be formulated
which give a performance equal to or better than existing
water-soluble and solvent-based systems. Furthermore, the
novel coatings of the present invention have displayed ex-
cellent paint stability over long periods of time without
impairment in performance.
Another advantage of the coatings of the present
invention is that they require much less neutralizing amine
than most conventional water-based coatings. In most water-
-based coatings, the amine is used to improve the water-dis-
persibility of the acidic po]ymer resin. The coatings of
the present invention may be formulated with much less amine
since none is required to neutralize the polyether polyol
components. For example, where the neutralizing amine is
dimethylaminoethanol, a conventional water-based coating
might require from 5-15%, by weight, of amine on the paint
solids. Coatings of the present invention can be formulated
with 1-3~ of amine on the same basis. Proportional reductions
can also be made if amines of different molecular weight such
as ammonia or triethyl amine are used. Since high levels of
amine are undesirable pollutants, the reductions described
are significant and desirable.
- 15 -
06SS~9~
Although the compositions of the present invention are water-
dispersible, they may be formulated into high performance coatings using
organic solvents as whole or partial replacements for the water. However,
since one of the objectives of the present invention is to minimize pollution
potential, it is preferred to use water as the solvent.
When it is desired to use the blend of the (A) polyether polyol
and the (B) vinyl polymer as a coating resin that is convertible to the
thermoset state, a compatible aminoplast cross-linking agent is used in a~
amount varying between 10% and 50%, by weight, based on the total weight of
(A) and (B).
The aminoplast cross-linking agents used in the present invention
may be either alkylated or unalkylated. They should be alkylated when used
in coating compositions but for other uses such as in laminating operations,
adhesives and mol~ing compositions among others they are preferably unalky-
lated.
The alkylated aminoplast cross-linking agents can be prepared
by reacting a urea with an aldehyde such as formaldehyde and then alkylating
said urea-formaldehyde reaction product with a lower alkanol such as methanol,
ethanol, propanol or butanol. In addition to urea per se, one could make
use of ethyleneurea, thiourea, and the like. Additionally, one can make
use of the amino-triazine aldehyde reaction products that have also been
alkylated with comparable alkanols. In this connection, attention is
directed to United States Patent No. 2,197,357 issued April 16, 1940 to
Widmer, et al, which shows a substantial plurality of amino-triazines re-
acted with aldehydes that are then alkylated by reaction with a substantial
plurality of compounds containing an alcoholic hydroxy group. The said
patent discloses a plurality of guanamines such as formoguanamine and
acetoguanamine which can be used to form compatible alkylated amino-
- 16 -
i
S~91
plast cross-linking agents. These cross-linking agents can be, and prefer-
ably are, monomeric. Illustrative of such a monomeric aminoplast cross-
linking agent is hexakis (methoxymethyl) melamine. This monomeric compound
can be prepared by a plurality of different processes such as those shown in
United States Patents 2,918,452 issued December 22, 1959 to Kun et al and
2,998,411 issued August 29, 1961 to Housekeeper. Unmixed ethers of the
polymethylol triazines can be used as well as mixed ethers such as the tetrakis
(alkoxymethyl) benzoguanamines may be used which are disclosed in United
States Patents 3,091,612, issued May 28, 1963 to Stevens. A lengthy dis-
- 10 ser~ion on fully mixed ethers of hexamethylol melamine is set forth in
United States Patent 3,471,388, issed October 7, 1969 to Koral. The un-
alkylated melamine resins are shown in United States Patent 2,260,239 issued
October 21, 1941 to Talbot.
In addition to the urea family and the triazine family of alky-
lated aminoplast cross-linking agents, one may also make use of the aniline
formaldehyde reaction products, a plurality of which are available commercial-
ly. These aniline reaction products should be limited to use in those com-
positions in which darker colors are not objectionable.
In addition to using these cross-linking agents in the monomeric
state, one may use low polymers of these reaction products such as dimer,
trimer, tetramers, and the like and mixtures thereof. It is generally prefer-
red to utilize a cross-linking agent that has an average molecular weight not
greater than about 1,500.
If water-dilutability of these cross-linking agents is desired,
methanol is preferably used as the alkylating agent. These aminoplast cross-
linking agents may be used either singly or in combination with one another.
In either case, the weight proportions remain the same.
In general, the most efficient aminoplast cross-linking agents
are the highly alkylated, largely monomeric resins. For example, commerical
grades of hexamethoxymethyl-
- 17 -
,:,
~065S~9~
melamine are very suitable cross-linking agents for the polyol/vinyl polymer
compositions. Similarly, highly alkylated urea and benzoguanamine resins
are very suitable aminoplast cross-linking agents. Although the more mono-
meric materials, in a mixture of monomers, dimers, trimers, etc., are usually
preferred because of their efficiency and because of the better flexibility
of the resultant coatings, in some circumstances, a more polymeric, partially
methoxymethylated melamine cross-linking agent may be desirable in coatings
where faster cure is needed. When using partially polymerized partially
alkylated resins~ it is necessary to maintain compatibility, so that alkyla-
tion must not be too low or molecular weight too high.
As preferred cross-linking agents, mention is made of alkylated
Cl-C4 urea formaldehyde~ especially butylated urea-formaldehyde, alkylated
Cl-C4 benzoguanamine-formaldehyde and fully methylated urea-formaldehyde
cross-linking agents.
It has been indicated hereinabove that the compositions of the
present invention make novel coating systems which result in extremely hard
and mar-resistant coatings which are nevertheless very flexible. It is
possibleon the other hand to formulate soft and rubbery coatings which are
similar in appearance to vinyl organosol coatings. When the selected poly-
ether polyol resins, the non-gelled anionic vinyl polymeric materials, and
the compatible alkylated aminoplast cross-linking agents are used, stable
water-dilutable systems can be formulated free of any organic solvents, which
give a performance equal to or better than existing water-soluble and solvent
based systems.
With normal water-soluble coating systems, it is difficult to ob-
tain paint stability. The novelcoatings of the present invention have dis-
played excellent paint stability over long periods of time without impair-
ment in performance.
- 18 -
106S5~9~
The following is a typical illustration of the procedure for the
preparation of the water-dispersible compositions of the present invention.
These examples are set forth primar;ly for purposes of illustration and any
specific enum-
- 18a -
~ 6599~
1 eration of detail contained therein should not be interpreted
as a limitation on the case except as is indicated in the
appended claims.
Example 1
Into a suitable reaction vessel equipped with a
stirrer, a nitrogen inlet tube and a reflux condenser there
is introduced 50 parts of polyether D. There is then added
50 parts of a monomer blend comprising 50.5% n-butylacrylate,
22.95% styrene, 6.15% acrylic acid, 18.4% of 2-hydroxyethyl-
acrylate, together with 1% of di-t-butylperoxide and 1% of
n-dodecyl mercaptan. The catalyzed monomer mixture is added
slowly to the polyol under a blanket of nitrogen at 160C.
over a period of about two hours. The polymerization temper-
ature is maintained at 160C. for an additional one to two
hours. The reaction product is then cooled to room temperat-
ure and the resultant resin is 100% non-volatile and had a
viscosity of 1,140 poises at 25C. The Gardner color is less
than one.
Example 2
Into a suitable mixing vessel, there is introduced
84 parts of a mixture of the polyol and acry].ic polymer of
Example 1 and 28 parts of hexakis(methoxymethyl)melamine fol-
lowed by 3 parts of dimethylamino ethanol, DMAE, and 0.5 part
of n-dodecyl benzene sulfonic acid, an acid catalyst. To
the resultant mixture, there is added 88 parts of titanium
dioxide (rutile type) under high speed agitation. After good
dispersion of the pigment, which is generally achieved in
about 15-20 minutes, 240 parts of deionized water are added
in small portions. The resultant aqueous paint of about 45%
solids has a pH of 7.5 and a Ford cup No. 4 viscosity of 45
seconds. The aqueous paint was then sprayed on cold rolled
steel panels that had been pretreated with zinc phosphate.
The coated panels are then baked at 150C. for 20 minutes.
- 19 -
~0655~9~
1 The film properties on these panels are shown in Table 1
hereinbelow.
Example 3
Example 1 is repeated in all essential details ex-
cept that there is used 30 parts of the polyether polyol D
and 70 parts of the same acrylic monomer mix. The polymeri-
zation temperature is 145C. and the viscosity at 25C. was
very high.
Example 4
Example 2 is repeated in all essential details ex-
cept that there is used 70 parts of the mixture of the polyol
and the acrylic polymer and 30 parts of hexakis(methoxymethyl)-
melamine, 1.8 parts of dimethylaminoethanol, 0.4 part of n-
-dodecyl benzene sulfonic acid, and 80 parts of titanium di-
oxide. After the mixing, sufficient deionized water was added
in small portions so as to produce a solids content of the
paint in water of 39.0%. The paint was sprayed on a number
of cold rolled steel panels pretreated with iron phosphate.
Some of the panels were baked at 150C. for 20 minutes while
others were baked at 175C. for 20 minutes. The film proper-
ties on these panels are shown in Table 1 hereinbelow.
Example 1 is repeated in all essential details ex-
cept that there is used a total of 35 parts of the acrylic
monomer composition as used in Example 1 together with 35
parts of polyether E. The polymerization is carried out at
165C. The resinous polymeric mixture, in combination with
30 parts of hexakis(methoxymethyl)melamine, is then emulsified
with 125 parts of water in the presence of 2.5 parts of di-
methylaminoethanol to provide a 44% solids solution. Theviscosity of the emulsion at 25C. was Z6 on the Gardner-Holdt
scale (234 poise). The emulsion had a clear bluish appearance.
- 20 -
1065S~9~
1 Example 6
Example 4 is repeated in all essential details ex-
cept that 70 parts of the polyol polymer blend of Example
5 obtained before the emulsification, are blended with 30
parts of a salicylic acid reaction product of dimethoxymethyl
diethoxymethyl benzoguanamine and 2.25 parts of diethanolamine,
instead of dimethylaminoethanol. The water dispersed paint
of 47% solids was sprayed on a number of cold rolled steel
panels pretreated with zinc phosphate. After spraying, some
of the panels were baked at 175C. for 20 minutes. The re-
sults are set forth hereinbelow in Table 1.
Example 7
Into a suitable reaction vessel equipped as in Ex-
ample 1, there is introduced 35 parts of polyether polyol D
to which there is added 35 parts of a mixture of the follow-
ing monomers: 54. 8 ~ of n-butylacrylate, 26.5% styrene, 14.9%
acrylic acid, together with 1.9~ of di-t-butylperoxide and
1.9~ of n-dodecyl mercaptan. The monomeric mixture is added
slowly to the polyol under a blanket of nitrogen at a temp-
erature of 160C. over a period of about 2 hours. The reac-
tion temperature is maintained after the addition is complet-
ed at 160C. for an additional 1 to 2 hours. The reaction
product was cooled to room temperature followed by the addi-
tion of 30 parts of hexakis(methoxymethyl)melamine. The re-
sultant 100~ non-volatile resinous mixture is then emulsified
in the presence of 2.5 parts of DMAE with 65 parts of deion-
ized water to 60% solids. The viscosity of the emulsion at
25C. was 100 poises and had a clear bluish appearance.
Example 8
In a suitable mixing vessel, there is introduced
165 parts of the clear emulsion of Example 7. To this are
added 0.4 part of n-dodecyl benzene sulfonic acid and 80
parts of titanium dioxide. After the dispersion of the pig-
- 21 -
~06599~
1 ment in 10-15 minutes, 55 pa-ts of deionized water is added
in small portions to produce the water dispersed paint of
60~ solids. Films are drawn down on cold rolled steel panels
pretreated with iron phosphate and the films are baked at
150C. for 20 minutes. The film properties are shown in Table
1 hereinbelow.
Example 9
Example 7 is repeated in all essential details ex-
cept that there is used only 25 parts total of the monomer'
mix used in Example 7 and 75 parts of the polyether polyol
D. The polymerization was carried out at 150C. The result-
ant polymer-polyol of 100% solids had a viscosity of 384
poises at 25C. and a Gardner color of less than one.
Example 10
The procedure of Example 2 is followed in all es-
sential details in which 70 parts of the blend of polyol and
; acrylic polymer of Example 9 are blended with 30 parts of
hexakis(methoxymethyl)melamine and to the 100 parts of the
polyol/acrylic polymer/cross-linking agent blend, there is
mixed 80 parts of titanium dioxide pigment. There is used
4.1 parts of diisopropanolamine. The paint was cut with de-
ionized water to an 80% solids and films were drawn down on
cold rolled steel panels pretreated with iron phosphate and
the films were then baked at 150C. for 20 minutes. The film
properties on the steel plates are found in Table 1 herein-
below.
Example 11
Example 1 is repeated in all essential details ex-
cept there is used only 25 parts total of the polymerizable
monomers used in Example 1 and 75 parts of the polyether poly-
ol E. The polymerization is carried out at 150CC. and a 100~
solids solution of the mixture of polymer and polyol was Z6+on
the Gardner-Holdt scale at 25C. and had a Gardner color of
106599~
1 less than one.
Example 12
70 Parts of the mixture of the polyether polyol
and the acry]ic polymer of Example 11 are blended with 30
parts of hexakis(methoxymethyl)melamine which is then blend-
ed with 80 parts of titanium dioxide pigment. There is used
2 parts of diethanol amine and 0.4 part of n-dodecyl benzene
sulfonic acid. The paint was cut to a solids content of 65%
with deionized water. Cold rolled steel panels pretreated
with zinc phosphate were coated with films of this paint and
they were then baked at 150C. for 20 minutes. The film prop-
erties are shown for this paint in Table 1 hereinbelow.
Example 13
An acrylic resin is prepared in a conventional
manner by polymerizing a mixture of 41 parts of n-butylacryl-
ate, 50 parts of methyl methacrylate and 9 parts of acrylic
acid in 2-ethoxyethanol and using dicumyl peroxide as a cat-
alyst and dodecyl mercaptan as a chain transfer agent to yield
a 75% solids solution of the polymer in the solvent. The
polymeric material has a molecular weight of about 10,000-
-15,000 and has an acid number of 72. 50 Parts (solids) of
the acrylic polymer is blended with 50 parts of polyether ,
polyol J. Thereupon, 70 parts of this blend are mixed with
29.2 parts of hexakis(methoxymethyl)melamine and 0.8 part
of dodecyl benzene sulfonic acid. Methyl diethanol amine is
used in a sufficient amount to neutralize at least some of
the carboxylic groups in the polymer. A paint is prepared
therefrom by adding titanium dioxide in a pigment/binder ratio
of 80/100 respectively. The paint is prepared substantially
in the manner set forth in Example 2 hereinabove. The paint
was cut with deionized water in a sufficient amount to pro-
duce an aqueous paint of about 54% solids, having a pH of
8.1 and a Ford cup No. 4 viscosity of 85 seconds. Films are
- 23 -
106S~9l
1 drawn down on cold rolled steel panels that had been pretreat-
ed with zinc phosphate and some of the coated panels are then
baked at 150C. for 20 minutes and other panels were baked
at 175C. for 20 minutes. The film properties on these panels
are shown in Table 1 hereinbelow.
Example 14
Example 13 is repeated in all essential details
except that in the place of the polyether polyol J there was
substituted an equal amount of polyether polyol K. The paint
was cut with deionized water to a solids content of 47~ sol-
ids and has a pH of 7.9 and a Eord cup No. 4 viscosity of
73. As in Example 13, films were drawn down on cold rolled
steel panels that had been pretreated with zinc phosphate.
Some of the coated panels were then baked at 150C. for 20
minutes while others were baked at 175C. for 20 minutes.
The film properties of these panels are shown in Table 1 here-
inbelow.
Example 15
Example 13 is repeated in all essential details
except that in the place of the polyether polyol J there was
used an equal amount of polyether polyol L. The ~aint was
cut with deionized water to a solids content of about 50~
and it had a pH of 7.9 and a Ford cup No. 4 viscosity of 75.
Films are drawn down, as in Example 13, on cold rolled steel
panels, pretreated with zinc phosphate, and some of the coat-
ed panels are then baked at 150C. for 20 minutes while others
are baked at 175C. for 20 minutes. The film properties of
these panels are shown in Table 1 hereinbelow.
- 24 -
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-- 26 --
1~;5~91
1 It has been indicated hereinabove that the water-
-dispersibility of the non-gelled, ionic vinyl polymer is
achieved by full or partial neutralization of the ionizable
carboxyl groups pendant from the chain. This can be accomp-
lished by the use of water-soluble amines of which a plural-
ity are available commercially and have been illustrated in
the examples set forth hereinabove. Additionally, one can
use ammonia or ammonium hydroxide or the alkali materials
such as sodium hydroxide, potassium hydroxide, lithium hy-
droxide and the like. The amount of the amine, the ammonia,ammonium hydroxide or alkali material used should be only
that amount which is required to achieve water-dispersibility.
If water-dispersibility is achieved by only partial neutrali-
zation of the ionizable carboxyl groups, that is sufficient.
However, if water-dispersibility is only achieved by full
neutralization of the ionizable carboxyl groups, then full
neutralization is necessary.
In the examples illustrating the use of the compo-
sition of the present invention as paints, the paint is spray-
ed on certain steel panels and then baked. In certain in-
stances, however, one could utilize the composition of the
present invention in electrodeposition coatings on metal pan-
els, such as steel panels, and Example 3, as set forth here-
inabove, is illustrative of a type of resin composition that
could be made readily adaptable to such use.
