Note: Descriptions are shown in the official language in which they were submitted.
~tj~3~35
PATENT
Case ~360A
NON-DIMER POLYA~IDES HAVING IMPROVED WATER SOLUBILITY
USEFUL AS FLEXOGRAPHIC/GRAVURE INK BINDERS
This invention relates to polyamide resins having improved water
solubility which are useful as flexographic/gravure ink binders. More
particularly, this invention relates to polyamide resins which are
essentially free of dimeric and higher polymeric fat acids.
U.S. Patent No. 3,776,865 to Glaser and Lovald discloses polyamide
resins obtained by reactiny an acid component comprised of a polymeric
fat acid and another dicarboxylic acid with an amine component compris-
ing isophorone diamine or mixtures thereof with an alkylene diamineO At
least 12.5 carboxyl equivalent percent of the polymeric fat acid is
employed. The patentees disclose that these resins are useful as bin-
ders applied by aqueous systems, particularly in flexographic/gravure
inks where water reducibility is desired.
U.S. Patent 4,051,087 to Scoggins et al describes copolyamide
resins useful as hot melt adhesives, molding resins, coatings or films.
These are achieved through the use of substantially equivalent amounts
of carboxyl and amine, i.e. a 1:1 ratio, proving essentially neutral
resins. Only a slight excess, up to 5 mol percent of carboxyl or amine
, may be present. Examples I, II, III and V employed a polymeric (dimer-
ic) fat acid, while Example IV employed azelaic acid in the absence ofthe dimer acid. The Example IV product is indicated as inferior to the
polyamide employing the dimeric fat acid.
-1- ~
~2~3895
U.S. Patent 3,781,234 to Drawert et al is another patent describing
polymeric fat acids polyamides useful as hot melt adhesives. Approxi-
mately stoichiometric amounts of amine (ethylene diamine) and a carboxyl
are employed, providing essentially neutral polyamides, neither acid
value or amine value substantially exceeding the other. A copolymer-
izing C19 acid, heptadecane dicarboxylic acid is required along with the
dimerized fatty acid.
U.S. Patent 4,055,525 to Cheng describes a polyamide again useful
as a hot melt adhesive. Substantially equivalent amounts of amine
(hexamethylene diamine) and carboxyl are employed, so that a neutral
polymer is provided. The acid component is comprised of a C19 diacid in
admixture with another aliphatic dicarboxylic acid containing 5-10
carbon atoms.
Polyamide resins prepared from dimeric and/or higher polymeric
lS fatty acids for use in flexographic1gravure inks are dissolved in vola-
tile organic solvents, such as the lower alkanols. Environmental con-
cern over the amounts of volatile organic solvents in the atmosphere has
led to a desire to use aqueous solutions that have less volatile organic
solvents contained therein. In order to accommodate the reduced levels
of volatile organic solvents, the polyamide resins used as binders in
flexographic/gravure inks should have increased water solubility and yet
retain the other desirable properties of polyamide resins, based on
polymeric fat acids.
The present invention provides polyamide resins which are acid
terminated, i.e. an equivalent excess of acid is used in relation to the
diamine so as to provide an acid value greater than 30. The resins
ideally contain no polymeric fat acid (dimeric fat acid), although a
small amount, up to 5 carboxyl equivalent percent may be tolerated
without unduly sacrificing the advantageous properties of the products
of the present invention, particularly as a binder for inks having
increased water solubility. The polyamide resins are prepared from a
mixture of a medium chain (12-26 carbon) dicarboxylic acid and a short
chain (2-10 carbon) dicarboxylic acid. A short chain (2-6 carbon) mono-
,,
..
-
~2~ 39~,
carboxylic acid may be employed primarily as a chain stopper; however,
its presence is not necessary and may be omitted. The acids are reacted
with a diamine having from 2-12 carbon atoms.
In its broadest scope, the present invention relates to polyamide
resin compositions obtained by the reaction of an acid component
comprised of a medium chain dicarboxylic acid having from 12-26 carbon
atoms and an amine component comprised of an aliphatic diamine
containing from 2-12 carbon atoms wherein the amine equivalent of the
diamine employed is less than the carboxyl equivalents of the acid
component so as to provide an acid value of the resin greater than 30
and the acid value exceeds the amine value by at least 20 units.
When the acid component contains a copolymerizing short chain
dicarboxylic acid, the products of the present invention may be
described as polyamide resin compositions formed from, or obtained by,
the amidification or condensation reaction of
(A) An acid component comprising
(1) about X equivalent percent of a medium-chain dicarboxylic acid
having from 12 to 26 aliphatic carbon atoms;
(2) about Y equivalent percent of a short-chain acyclic aliphatic
dicarboxylic acid having from 2 to 10 aliphatic carbon atoms;
and
(B) an amine component comprising about Z equivalent percent of a
diamine having from 2 to 12 aliphatic carbon atoms or mixtures
thereof; wherein the ratio of Z to the sum of X and Y is less than
1, so as to provide an acid value greater than 30.
The preferred polyamides are those wherein the ratio of Z to
the sum of X and Y is less than about 0.9, more preferably ranges
from about 0.50 to about 0.85, and most preferably from about 0.65
to about 0.85.
Where a monocarboxylic acid is employed in the acid component,
the acid component can be defined dS being a mixture of:
(a) about X equivalent percent of a medium chain dicarboxylic acid
having from 12-26 aliphatic carbon atoms;
, , . " ~ , .
~2~8895
;
(b) about Y equivalent percent of a short chain acyc1ic aliphatic
dicarboxylic acid having from 2-10 aliphatic carbon atoms and
(c) about Y' equivalent percent of a short chain aliphatic mono
carboxylic acid having from 3-5 aliphatic carbon atoms.
In such case, the ratio of Z to the sum of X, Y and Y' is less than 1.
As is apparent in a situation where no monocarboxylic acid is employed,
Y' would be zero.
The invention also provides binder compositions flexographic/gra-
vure ink compositions containing such resins.
It has been found that the polyamide resins of this invention are
more soluble in flexographic/gravure ink compositions containing more
water and less volatile organic solvent than flexographic/gravure ink
compositions containing polyamide resins based on polymeric fat acids.
In spite of this increased water solubi;ity, however, the polyamide
resins yield ink coatings with acceptable water-resistancé and other
desirable properties.
The polyamide resins of the present invention are prepared by
reacting or polymerizing a mixture of an acid component which contains
at least two different carboxylic acids with an amine component contain-
ing at least one diamine. These resins are acid terminated resins in
that an equivalent excess of the dicarboxylic acids are used in relation
to the diamine, so as to provide an acid value of greater than 30.
Using such excess , the amine value will be low and the acid value will
exceed the amine value by at least 20. Thus, the amine value will be 10
or lower. A monobasic acid can also be used in the acid component as a
chain stopper. In achieving the acid value of at least 30, the ratio of
amine equivalents of the diamines to the carboxyl equivalents of the
acids is therefore less than 1, preferably less than about 0.9, more
preferably ranges from about 0.50 to about 0.85, and most preferably
about 0.65 to 0~85.
The polyamides of the present invention may be defined as a polymer
or resin obtained by the reaction of:
(A) an acid component comprising a mixture of
~L2~389~
(1) about X carboxyl equivalent percent of a medium chain
aliphatic dicarboxylic acid having from 12-26 carbon
atoms;
(2) about Y carboxyl equivalent percent of a short chain
alicyclic aliphatic dicarboxylic acid having from 2-8
carbon atoms;
and (B) an amine component comprising Z amine equivalent percent of an
aliphatic diamine containing 2-12 carbon atoms.
wherein the equivalent ratio of Z to the sum of X and Y is less than 1
so as to provide an acid value greater than 30. With such acid values,
the acid value will exceed the amine value by about 20.
When a monocarboxylic acid is employed, the acid component will
comprise a mixture of:
(1) X carboxyl equivalent percent of the medium aliphatic dicar-
boxylic acid defined above;
(2) Y carboxyl equivalent percent of the short chain dicarboxylicacid defined above; and
(3) Y' carboxyl equivalent percent of a short chain aliphatic
monocarboxylic acid having from 2-6 carbon atoms.
~ith an acid component as above, the ratio of Z to the sum of X, Y and
Y' is less than 1 so as to provide an acid value greater than 30.
The carboxylic acids useful in the present invention accordingly
can be divided into two groups on the basis of chain length. The acids
of one group have medium-chain length and the acids of the other group
have short-chain length. The medium-chain aliphatic dicarboxylic acids
are present in all of the polyamide resins of this invention. The other
group of acids, i.e. the short-chain carboxylic acids used to prepare
the polyamide resins of this in~ention, can be further subdivided into
two groups on the basis of functionality. In general, it is preferred
that the short-chain acyclic aliphatic dicarboxylic acids be used to the
exclusion of the short-chain aliphatic monocarboxylic acids (in which
case the amount Y' is zero), especially when the diamine chosen is
isophorone diamine, and that the short-chain aliphatic monocarboxylic
acids be used to the exclusion of the short-chain acyclic aliphatic
dicarboxylic acids (in which case the amount Y is zero), especially when
the diamine chosen is ethylene diamine.
--5--
~2~8895
The medium-chain aliphatic dicarboxylic acids (hereinafter referred
to as the medium-chain diacids) necessary in this invention have from 12
to 26 carbon atoms, preferably from 16 to 22. This class of dicarbox-
ylic acids includes not only the homologous series beginning with do-
decanedioic acid and extending to the 24 carbon diacid, but also in-
cludes dicarboxylic acids that have branched alkyl chains and alicyclic
structures in the molecule as well.
These medium chain dicarboxylic acids may be represented by the
formula
H O O C - R1 - C O O H
where R is a divalent aliphatic hydrocarbon radical containing from 10
to 24 carbon atoms, straight or branched chain, acyclic or alicyclic.
Preferably, R contains 14 to 20 carbon atoms.
A preferred class of medium-chain diacids are those having a car-
boxylic ring and three substituents wherein one substituent is a car-
boxyl group, a second substituent is an alkyl group having more than
three aliphatic carbon atoms, and a third substituent is an alkyl group
that is terminally substituted with a carboxyl group. Examples of the
medium-chain diacid of this preferred class may be obtained as the Diels
Alder reaction products of acrylic acid with a fatty acid having two
conjugated ethylenic unsaturations. A preferred example of the medium-
chain diacids is 2-n-hexyl-5-(7-carboxyl-n-heptyl)-cyclohex-3-ene car-
boxylic acid which is a C21 acid available ~kom Westvaco, Charleston
Heights, South Carolina, as Westvaco DiAcid.
The short-chain acyclic aliphatic dicarboxylic acids (hereinafter
referred to as short-chain diacids useful in this invention) have from 2
to 10 carbon atoms in an unbranched hydrocarbon chain. The short-chain
diacids can be characterized as a homologous series of dicarboxylic
acids which begins with oxalic acid, ends with decanedioic acid, and
includes each member in-between. The short chain diacids may also be
represented by the formula
H O O C - (R2)n - C O O H
where R2 is defined as a divalent, straight chain alkylene radical
having 2-& carbon atoms and n is O or l. When n is 0, the acid is
oxalic acid, HOOCCOOH. When n is 1, the acids include the dicarboxylic
acids from propanedioic (malonic) to decanedioic (sebacic). A prefer-
red class are those in which n is 1 and R2 contains from~-8 carbon atoms.
3~ trade ~k - 6 -
~ ~889S
The preferred short-chain diacids are azelaic acid and adipic acid.
The amounts of short-chain diacid and medium-chain diacid used in
the polyamides of this invention are preferably chosen such that the
ratio of equivalents of the short-chain diacid to equivalents of the
medium-chain diacid range from about 4:1 to about 0.66:1, more prefer-
ably from about 3:1 to about 0.8:1, and most preferably from about 1:1
to 2:1.
The short-chain aliphatic monocarboxylic acids (hereinafter refer-
red to as short-chain monoacid) useful in this invention have from 2 to
6 carbon atoms. These monocarboxylic acids may be represented by the
formula
R3 - C 0 0 H
where R3 is d straight or branched chain alkyl group containing from 1-5
carbon atoms. The short chain acids are exemplified by acetic,
propionic acid, n-butanoic acid, isobutanoic acid, and the like. The
preferred short-chain acid is propionic acid.
The amounts of the medium-chain diacid and short-chain monoacid
used in the polyamides of this invention are preferably chosen such that
the ratio of equivalents of the medium-chain diacid to the equivalents
of the short-chain monoacid ratio of about 1:1 to about 5:1, more
preferably from about 2:1 to about 4:1, and most preferably about 3:1.
The acid component of the present invention will accordin~ly be
composed as follows:
Acid Component - 100 Equivalents Eq.%
Medium Chain Dicarboxylic Acid 20-100
Short Chain Dicarboxylic Acid 0- 80
Short Chain Monobasic Acid o- 35
Carboxyl Equivalent Percent 100
The polyamides of this invention are prepared from mixtures that
are substantially free of polymeric fat acids. These polymeric fat
acids, which can be characterized as long-chain polybasic acids, are
described in U.S. Patent No. 3,776,865. These polymeric fat acids are
`` ~2~i~895
derived by polymerizing either saturated or unsaturated fatty acids. It
has been found that the amount of polymeric fat acid used in the poly-
amides of this invention should be minimized to obtain improved water
solubility in the polyamide resin. The mixtures from which the resins
of this invention are prepared are substantially free of polymeric fat
acids, i.e. they may contain an amount of a polymeric fat acid equal to
as much as 5 equivalent percent of the polyamide reaction mixture but
preferably less than 5 equivalent percent and most preferably zero
equivalent percent. With amounts of about 10 equivalent percent, i.e.
12.5 equivalent percent of a polymeric fat acid, the properties are
adversely a~fected to the point where the products are insoluble or
gelled and unsuitable for use in flexographic inks.
The diamine used to form the polyamide resins of this invention is
comprised of at least one aliphatic diamine having from 2 to 12 ali-
phatic carbon atoms. The preferred diamines can be divided into two
preferred groups. One group consists of cyclic aliphatic diamines
having from 8-12 aliphatic carbon atoms, e.g. isophorone diamine. The
other preferred group is comprised of short-chain alkylene diamines
which can be represented by the formula:
H2N-R-NH2
wherein R is an alkylene radical having from 2 to 8 carbon atoms. R may
be branched or straight chained, the straight chain radicals being pre-
ferred. Specific examples of short-chain alkylene diamines are ethylene
diamine, diamino-propane, diamino-butane, and hexamethylene diamine.
The polyamide resins of this invention will contain the structural
unit
H H 0 0
Il 1~ " 11
- N - R - N - and - C - R1 - C -
where R and R2 are as earlier defined. Where a short chain dicarboxylic
acid is also employed, the resin will also contain the structural unit
O O
Il 1~
- C - R2 - C -
--8--
389~
The short chain monocarboxylic acid is employed as a chain stopper
which, along with the acid and amine ratios employed, will control the
degree of polymerization of the mixture, the number of recurring
structural units, and the amine and acid numbers.
The resins are prepared from mixtures containing a dicarboxylic
acid component and a diamine component by known methods for the polymer-
ization of diacids and diamines to form polyamides. In general, a
mixture of the diacid component and the diamine component is heated to a
temperature between about 100C and 250C in a vessel equipped for the
removal of the by-product water formed in the polyamidification reac-
tion; e.g. a vessel fitted with a distillation column and condenser so
as to remove water from the reaction zone.
Typically the reaction mixture will be heated at lower temperatures
initially to avoid any volatilization and loss of any short chain mono-
acid which may be employed, after which the temperature is raised to thehigher reaction temperature. Thus, it is common to heat at about 140C.
for about l hour followed by raising the temperature to about 250C and
reacting for about l.5-3 hours.
Similarly, a portion of the charge of the medium-chain diacid can
be reserved from the initial charge of reactants. The initial reactant
mixture can be initially reacted to ensure that substantially all of the
short-chain monoacid is incorporated into the resin. The reserved
portion of medium-chain diacid is then charged and the resulting mixture
is allowed to react to obtain an acid terminated product, For example,
from about 25% to about 50~ of the medium-chain diacid to be charged is
reserved from the initial charge which is heated at about l40C for one
hour. The reserved portion of medium-chain diacid is then added to the
reaction mixture and the temperature is raised to about 250C for about
l l/2 to 3 hours to obtain a product having acid termination.
The degree of polymerization of the mixture should be controlled,
along with the choice of ratio of diamine to diacids, to obtain a poly-
amide having a high acid value (greater than 30). The acid value of the
polyamide preferably should be grea-ter than about 50, Generally, the
products will have an acid value between 30 up to about 100. With such
acid values, the amine numbers will be low, less than about 10, ap-
~2~i8~395
, . .
proaching a value of about 1-5. Thus, the acid number will exceed -the
amine value by about 20, and generally higher.
The polyamide resins of this invention form the binder compositions
of this invention when dissolved in an aqueolls solvent containing an
organic amine. The resin is added to the solvent in an amount of about
30% to about 40% resin solids based on the weight of the solvent.
Examples of suitable organic amines include primaryJ secondary and ter-
tiary amines which can act as a base to salt the acid terminated poly-
amides. Particularly preferred organic amines are the dialkylaminoal-
kanols, such as 2-(N,N-dimethylamino)ethanol and
2-(N,N-diethylamino)ethanol.
The organic amine is present in the aqueous solution in an amount
sufficient to solubilize the chosen polyamide resin, In general, the
organic amine will be present in the aqueous solution in an amount
sufficient to theoretically neutralize the acid groups of the polyamide,
i.e. the amount of organic amine is stoichiometrically equivalent to or
greater than the acid value of the polyamide. For example, a 7.~%
solution of dimethylaminoethanol is stoichiometrically equivalent to a
polyamide resin having an acid value of about 70 used at the level of
40~ resin solids. A large excess of organic amine should be avoided
because retention of the organic amine in the cured binder may adversely
affect the water retention of the binder.
These binders are particularly useful in flexographic/gravure ink
compositions.
The flexographic/gravure ink compositions of this invention are
preferably made by dispersing a flexographic/gravure ink pigment in the
binder compositions of this invention.
It is an advantage of the present invention that less volatile
organic solvent is needed to solubilize the resins in the binder com-
positions used to make flexographic/gravure ink compositions of this
invention than is needed to solubilize the dimer acid resins of U.S.
Patent 3,776,865. Generally, the flexographic/gravure ink compositions
of this invention can contain less than about 25% by volume volatile
organic solvent. The preferred resins can be used to prepare binders
which contain even less volatile organic solvent, e.g. 5% to 20%, but
- 10-
i8~
which still yield flexographic/gravure ink coatings having good water
resistance.
EXAMPLES
The following Examples show the preparation and properties of
polyamide resins representative of the polyamide resins of this inven-
tion and the preparation and properties of comparative polyamide resins.
The polyamide resins of this invention are denoted by an arabic numeral
and the comparative polyamide resins are denoted by a letter.
Definitions:
In the following Examples, the following terms, abbreviations and
symbols have the following meanings:
MCD: 2-n-hexyl-5-(7-carboxyl-n-heptyl) cyclohex-3-ene carboxylic acid9
available from Westvaco as Westvaco DiAcid.
ADA: adipic acid
AZA: azelaic acid
PRA: propionic acid
IPD: isophorone diamine
EDA: ethylene diamine
RESIN PREPARATION
The resins described in the Examples below were prepared by charg-
ing the acid and amine reactants shown in the Tables to a reactor along
with about 1% of an 85% solution of phosphoric acid as a catal~st. In
Example 5, a portion of the MCD was indicated was reserved from the
initial charge and added after most of the PRA had reacted. The reac-
tion mixture was heated to 250C and held for 2 hours at that temper-
ature. The resulting resins had the softening point as determined by
the Ball and Ring method and the acid value, reported in milligram KOH
per gram of sample, in Table I below.
The resins of Comparative Examples A, 8 and C were prepared using a
polymeric fat acid available from Henkel Corporation as VERSADYME~ 204
which has the following analysis:
89~i
Saponification Value (S.V.) 198.5
Acid Value (A.V.) 189.2
Thermosel Viscosity (25.) 54.4 poises
Color (Gardner - no solvent) 7~
Fe 3.7 ppm
p 25 ppm
S 44 ppm
Iodine Value 99.9
70 Monomer (M) 10.9
% Intermediate (I) 5.3
g Dimer (D) 71.1
% Tri~er (T) 12.6
-12-
~ ~88~3~
:
a~
a) _
O ~ ~D O _ ~ ~O ~n C ~
oo ~ Lf) u~ a~ c~ c c
V~ .C
.~
_ c u~ o In
~c ~ I~ ~ 00 r~
~-~ oo O~ ~ ~ = ~ a~
o V~
Z ~
_ cc ~rco
~ o ~
Zo
C~ .
Z Q aJ. '~
_ _ _N ~- _ --' I --
'~1 IC-I
Q. Cl~
Z C:. _ I ~ I I I I I
_~: ~
C~ -- ~ I I I ~ I I I
~:~r
O ~
Cl
O
~cr
'~ a
Cl ~ C~
Q_ ~ I I I I I _ ~ _
E C`~ C ~ c ~
LLJ
-13-
The solubility of the resins described in Table I in the following
two solvents was determined.
Solvent ~l was a mixture of 92.6~ deionized water and 7.4% di-
methylaminoethanol. Solvent ~2 was a mixture of 77.1~ deionized water,
21.8~ diethylaminoethanol, and l.1% dimethylaminoethanol.
The solubility of the resins in the indica~ed solvents are indi-
cated in the table by the use of the following symbols:
solubletfluid - very high in viscosity
-insoluble fluid
-Ginsolubletgel
BGborderline gel
+Gsoluble/gel
The remdining symbols in the table indicate the Gardner-Holdt
viscosity of the solution obtained by mixing the resin and the indicated
solvent.
TABLE II
SOLUBILITY AND VISCOSITY OF POLYAMIDE RESINS
EXAMPLESOLVENT #1 SOLVENT ~2
Resin solids (wt.%)
l +G Al+ A4+ +G X+ A2-
2 +G L+ A4 +G + Al
3 BG Y+ A2 +G ~G A-Al
4 -G S A3 ~ Z4~ A-Al
Z5-6 +G A X-Y +G A-
A -G -G - +G Zl A2
B BG - - +G Zl A2
C -G G- A2-3 ~ T-U A2
The results shown in Table II show that the representative resins
of this invention have better solubility, particularly in a solvent
-14-
`~` 3L~g~3~39~
having a very low concentration of organics, than the comparative poly-
amides prepared from polymeric fat acids.
Samples of the polyamide resins shown in Table I were mixed with n-
propanol and titanium dioxide to prepare white inks containing 33.3% by
weight titanium dioxide, 20% by weight resin, and 46.7% by weight n-
propanol. These inks were rolled out at l l/2 ml wet on glass to yield
inks having the gloss shown in Table III. Samples of the inks were also
rolled out on polyethylene and allowed to dry. The polyethylene samples
were then imlnersed in water at 25C for 24 hours~ The samples were then
subjected to 50 manual rubs with cotton wadding. The samples were rated
on a scale of l-lO with lO representing a finding that the test had no
effect on the ink coating.
The gloss of the resulting inks and the results of the wet rub
tests are shown in Table III below.
TABLE III
INK GLOSS AND WATER RESISTANCE
GLOSS
EXAMPLE 60 20C WET RUB
~ l 85 16 lO
2 78 39 lO
3 76 45 lO
4 64 17 lO
67 20 lO
A 89 76 lO
B 82 5l lO
C 86 61 lO
The results shown in Table III indicate that the resins of this
invention yield inks having good gloss and excellent resistance to
water.
-15-
~L~2~38~35
EXAMPLE 6
In this example, polyamides were prepared containing polymeric fat acids
at a level of 12.5 equivalent percent, the lowest level shown in U.S.
Patent 3,776,865 to Glaser et al. A polyamide resin was also prepared
from an acid component containing no polymeric fat acid, but having a
low acid value of 16.5. These resins were evaluated and compared to the
polyamide of Example 3 of the present invention, which has an acid value
of 35.1. Five comparative resins were prepared using the Resin Prepa-
ration procedures disclosed earlier. In those resins employing a poly-
meric fact acid, a polymeric fat acid was employed having the sametypical analysis given earlier. The amounts of the reactants, the acid
value of the product and results of solubility of the products can be
seen in the following Table IV.
TABLE IV
Acid
Reactants Value Solubil_ty in Solvent
Example PFA MCD ADA IPDA (Actual) C-l C-2
D 12.5 37.5 50 84.4 37.2 IS Gel
E 12.5 - 87.5 89.6 35.7 Gel Gel
F - 50 50 92.9 16.5 IS-PS IS-Gel
G 12.5 37.5 50 93.2 14.4 IS-PS IS-Gel
H 12.5 - 87.5 96.6 11.4 IS-PS IS-Gel
Example 3 - 50 50 85 35.1 T-U* Gel
IS = Insoluble
PS = Phase Separation
* = Gardner Holdt Viscosity
C-1 and C-2 = Two Solvents described earlier and used in
Table II - 30% Resin Concentration by weight
-16-
3895
As can be seen from the foregoing, the resin of the present inven-
tion has better solubility than the compardtive resins D, E, G and H
prepared with 12.5 equivalents of polymerized tall oil fatty acids and
resin F (with no polymeric fat acid), resins D through F all having
actual acid values below 30.
