U.S. patent application number 10/654661 was filed with the patent office on 2004-10-21 for rosin phenolic resins and uses related thereto.
Invention is credited to Fontana, Thomas.
Application Number | 20040210029 10/654661 |
Document ID | / |
Family ID | 32927185 |
Filed Date | 2004-10-21 |
United States Patent
Application |
20040210029 |
Kind Code |
A1 |
Fontana, Thomas |
October 21, 2004 |
Rosin phenolic resins and uses related thereto
Abstract
Rosin modified phenolic resins are prepared by reacting together
resin acid, fatty acid, tri- or higher-functional phenolic compound
and aldehyde. The fatty acid may be Monomer (derived from the fatty
acid dimerization process). The reaction mixture may optionally
include .alpha.,.beta.-olefinically unsaturated carbonyl compounds
and/or polyol. The resin may be dissolved in a solvent to form a
varnish. The resin may be used as a component of printing inks,
e.g., inks for lithographic or gravure printing.
Inventors: |
Fontana, Thomas;
(Jacksonville, FL) |
Correspondence
Address: |
Richard C. Stewart, II
International Paper
1422 Long Meadow Road
Tuxedo
NY
10987
US
|
Family ID: |
32927185 |
Appl. No.: |
10/654661 |
Filed: |
September 3, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10654661 |
Sep 3, 2003 |
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10384075 |
Mar 5, 2003 |
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Current U.S.
Class: |
528/144 |
Current CPC
Class: |
C09D 11/08 20130101;
C08G 8/34 20130101; C09D 11/103 20130101; C08G 8/32 20130101 |
Class at
Publication: |
528/144 |
International
Class: |
C08G 008/04 |
Claims
1. A process for forming a resin from reactants, the reactants
comprising fatty acid, resin acid, aldehyde and phenolic compound
that is at least trifunctional with respect to aldehyde reactivity,
the process comprising maintaining the reactants at elevated
temperature for a time sufficient to form the resin.
2. The process of claim 1 wherein the reactants further comprise
polyol.
3. The process of claim 1 wherein the reactants further comprise
.alpha.,.beta.-olefinically unsaturated carbonyl compound.
4. The process of claim 1 wherein the reactants further comprise
metal oxide.
5. The process of claim 1 wherein the reactants comprise
phenol.
6. The process of claim 1 wherein the reactants further comprise
phenolic compound other than phenol.
7. The process of claim 1 wherein the resin has an acid number of
1-70.
8. The process of claim 1 wherein the resin has a softening point
of 100-230.degree. C.
9. The process of claim 1 wherein the resin has a softening point
in excess of 110.degree. C.
10. The process of claim 1 wherein the resin has a peak molecular
weight of 30,000-500,000.
11. The process of claim 1 wherein a 45 wt % solution of the resin
in PKWF 6/9 AR has a flow viscosity of 0.1-450 Pa.s at 25.degree.
C.
12. The process of claim 1 wherein a 45 wt % solution of the resin
in PKWF 6/9 AR has a flow viscosity of 0.1-150 Pa.s at 25.degree.
C.
13. The process of claim 1 wherein a 45 wt % solution of the resin
in PKWF 6/9 AR has a tan delta of infinite to 1.5.
14. The process of claim 1 wherein a 10 wt % solution of the resin
in M47 solvent has a cloud point of less than about 50.degree.
C.
15. The process of claim 1 wherein a 10 wt % solution of the resin
in M47 solvent has a cloud point of 50-150.degree. C.
16. The process of claim 1 wherein a 10 wt % solution of the resin
in M47 solvent has a cloud point of greater than about 150.degree.
C.
17. The process of claim 1 wherein a 10 wt % solution of the resin
in M47 solvent has a cloud point of 75-180.degree. C.
18. The process of claim 1 wherein the resin is completely soluble
in M47 at 10% solids at 180.degree. C.
19. The process of claim 1 wherein the resin is self-gelling in
mineral oil at a resin:mineral oil weight ratio of 1:1.5.
20. The process of claim 1 wherein the resin has a viscosity at 35%
solids of 50-350 mPa-secs as measured on a rotational
viscometer.
21. The process of claim 1 wherein the resin has a dilutability of
60-280 mLs toluene, DIN 3 at 21.degree. C., starting from 100 grams
of a 35% resin solids toluene solution.
22. The process of claim 1 wherein the resin is suitable for use as
a lithographic ink resin.
23. The process of claim 1 wherein the resin is suitable for use as
a gravure ink resin.
24. The process of claim 1 wherein phenol constitutes at least 20
wt % of phenolic compound present in the reactants.
25. The process of claim 1 wherein phenol constitutes at least 35
wt % of phenolic compounds present in the reactants.
26. The process of claim 1 wherein resin acids constitute 30-60 wt
% of the reactants, based on the total weight of the reactants.
27. The process of claim 1 wherein rosin is a source of resin
acids.
28. The process of claim 1 wherein fatty acids constitutes up to 65
wt % of the reactants, based on the total weight of the
reactants.
29. The process of claim 1 wherein fatty acid constitutes 5-40 wt %
of the total weight of the reactants, excluding fatty acid present
in rosin.
30. The process of claim 1 wherein fatty acid constitutes 10-40 wt
% of the total weight of the reactants, excluding fatty acid
present in rosin.
31. The process of claim 1 wherein the reactants comprise a rosin
selected from the group consisting of tall oil rosin, gum rosin and
wood rosin, and the fatty acid comprises compounds of the formula
R.sup.1-COOH wherein R.sup.1 is a hydrocarbyl group having at least
14 carbons.
32. The process of claim 31 wherein rosin constitutes 35-90 wt %,
fatty acid constitutes 10-35 wt %, and the total weight of phenolic
compound+aldehyde constitutes 10-30 wt %, based on the total weight
of the rosin, fatty acid, phenolic compound and aldehyde present in
the reactants.
33. The process of claim 32 wherein the weight of rosin in the
reaction mixture is at least 50% greater than the weight of fatty
acid present in the reaction mixture.
34. The process of claim 31 wherein the reactants further comprise
polyol.
35. The process of claim 34 wherein the polyol is
pentaerythritol.
36. The process of claim 31 wherein the reactants further comprise
.alpha.,.beta.-olefinically unsaturated carbonyl compound.
37. The process of claim 36 wherein the .alpha.,.beta.-olefinically
unsaturated carbonyl compound comprises maleic anhydride.
38. The process of claim 1 wherein fatty acid constitutes 5-40 wt %
of the total weight of the reactants, excluding fatty acid present
in rosin.
39. The process of claim 1 wherein aldehyde constitutes up to 40 wt
% of the total weight of the reactants.
40. The process of claim 1 wherein aldehyde constitutes 5-15 wt %
of the total weight of the reactants.
41. The process of claim 1 wherein phenolic compounds including
phenol constitute up to 50 wt % of the total weight of the
reactants.
42. The process of claim 2 wherein the polyol constitutes up to 15
wt % of the total weight of the reactants.
43. The process of claim 2 wherein the polyol constitutes 5-15 wt %
of the total weight of the reactants.
44. The process of claim 3 wherein the .alpha.,.beta.-olefinically
unsaturated carbonyl compound constitutes up to 8 wt % of the total
weight of the reactants.
45. The process of claim 3 wherein the .alpha.,.beta.-olefinically
unsaturated carbonyl compound constitutes 0.05-7 wt % of the total
weight of the reactants.
46. The process of claim 4 wherein the metal oxide constitutes
0.01-1 wt % of the total weight of the reactants.
47. The process of claim 1 wherein the reactants comprise rosin,
and rosin is a source of the resin acids.
48. The process of claim 1 wherein Tall Oil Rosin is a source of
the resin acids.
49. The process of claim 1 wherein gum rosin and/or wood rosin is a
source of the resin acids.
50. The process of claim 1 wherein the resin acid is selected from
resin acid salt, resin acid ester, resin acid dimer and resin acid
adduct.
51. The process of claim 1 wherein the resin acid is natural resin
acid.
52. The process of claim 51 wherein the fatty acid comprises Tall
Oil Fatty Acid or Monomer.
53. The process of claim 1 wherein the reactants comprise Monomer,
and Monomer is a source of the fatty acids.
54. The process of claim 1 wherein the reactants comprise
vegetable-based fatty acid, where the vegetable-based fatty acid is
a source of fatty acid.
55. The process of claim 1 wherein the reactants comprise animal
derived fatty acid, where the animal derived fatty acid is a source
of fatty acid.
56. The process of claim 1 wherein the reactants comprise fatty
acid ester, and fatty acid ester is a source of fatty acid.
57. The process of claim 1 wherein the reactants comprise
paraformaldehyde, and paraformaldehyde is a source of the
aldehyde.
58. The process of claim 1 wherein azeotropic distillation is not
used to remove water from the resin.
59. The process of claim 1 wherein an inert organic solvent capable
of azeotropic distillation of water at the elevated temperature is
not used as an entraining agent for azeotropic distillation of
water.
60. A resin prepared by the process of any of claim 1.
61. A varnish comprising a resin prepared by the process of any of
claim 1 and a solvent.
62. The varnish of claim 61 wherein the solvent is a
hydrocarbon.
63. A lithographic ink comprising a resin of claim 60.
64. A gravure ink comprising a resin of claim 60.
65. A process for preparing a resin, the process comprising
reacting reactants at elevated temperature, the reactants
comprising rosin, fatty acid, aldehyde and phenolic compound that
is at least trifunctional with respect to reactivity with aldehyde,
where the phenolic compound that is at least trifunctional
constitutes at least 25 wt % of all phenolic compounds used to form
the resin.
66. The process of claim 65 wherein phenol constitutes at least 35
wt % of the phenolic compounds.
67. The process of claim 65 wherein phenol constitutes at least 55
wt % of the phenolic compounds.
68. The process of claim 65 wherein the rosin constitutes up to 85
wt % of the reactants.
69. The process of claim 68 wherein rosin constitutes 35-70 wt % of
the reactants.
70. The process of claim 65 wherein the fatty acid constitutes up
to 65 wt % of the reactants.
71. The process of claim 70 wherein the fatty acid constitutes 5-40
wt % of the reactants.
72. The process of claim 65 wherein the aldehyde constitutes up to
40 wt % of the reactants.
73. The process of claim 72 wherein the aldehyde constitutes 5-15
wt % of the reactants.
74. The process of claim 65 wherein phenolic compound(s) constitute
up to 50 wt % of the reactants.
75. The process of claim 74 wherein phenolic compound(s) constitute
5-15 wt % of the reactants.
76. The process of claim 65 wherein the fatty acid comprises Tall
Oil Fatty Acid (TOFA).
77. The process of claim 65 wherein the fatty acid comprises
Monomer.
78. The process of claim 65 wherein the aldehyde comprises
formaldehyde.
79. The process of claim 65 wherein the rosin comprises gum
rosin.
80. The process of claim 65 wherein the rosin comprises tall oil
rosin.
81. The process of claim 65 wherein the reactants further comprise
polyol.
82. The process of claim 81 wherein the polyol constitutes up to 15
wt % of the components.
83. The process of claim 82 wherein the polyol comprises
pentaerythritol.
84. The process of claim 65 wherein the reactants further comprise
an .alpha.,.beta.-olefinically unsaturated carbonyl compound.
85. The process of claim 84 wherein the .alpha.,.beta.-olefinically
unsaturated carbonyl compound constitutes up to 8 wt % of the
components.
86. The process of claim 85 wherein the .alpha.,.beta.-olefinically
unsaturated carbonyl compound comprises maleic anhydride.
87. The process of claim 65 wherein the resin is self-gelling in
mineral oil at resin:mineral oil weight ratio of 1:1.5.
88. The process of claim 65 wherein the resin is completely soluble
in mineral oil at 10% solids at 180.degree. C.
89. The process of claim 65 wherein the resin has a softening point
in excess of 120.degree. C.
90. The process of claim 65 wherein a 45 wt % solution of the resin
in a hydrocarbon solvent has a flow viscosity at 25.degree. C. of
0.1 to 150 pascal-seconds.
91. The process of claim 65 wherein the resin is suitable for use
as a lithographic ink resin.
92. The process of claim 65 wherein the resin is suitable for use
as a gravure ink resin.
93. The process of claim 65 wherein azeotropic distillation is not
used to remove water from the resin.
94. The process of claim 65 wherein an inert organic solvent
capable of azeotropic distillation of water at the elevated
temperature is not used as an entraining agent for azeotropic
distillation of water.
95. A resin prepared by the process of claim 65.
96. A varnish comprising a resin prepared by the process of claim
65 and a solvent.
97. The varnish of claim 96 wherein the solvent is a
hydrocarbon.
98. A lithographic ink comprising a resin of claim 95.
99. A gravure ink comprising a resin of claim 95.
100. A process for preparing a resin, the process comprising
reacting reactants at elevated temperature, the reactants
comprising resin acid, fatty acid, aldehyde and phenolic compound
that is at least trifunctional with respect to reactivity with
aldehyde, where the fatty acid contributes at least 5% of the
weight of the listed reactants, and the resin has a softening point
of at least 105.degree. C.
101. The process of claim 100 wherein the resin has a softening
point of at least 120.degree. C.
102. The process of claim 100 wherein the fatty acid contributes at
least 15% of the weight of the listed reactants.
103. The process of claim 100 wherein the fatty acid contributes at
least 20% of the weight of the listed reactants.
104. The process of claim 100 wherein phenolic compound that is at
least trifunctional with respect to reactivity with aldehyde
constitutes at least 5 wt % of all phenolic compounds present among
the reactants.
105. The process of claim 100 wherein phenolic compound that is at
least trifunctional with respect to reactivity with aldehyde
constitutes at least 10 wt % of all phenolic compounds present
among the reactants.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention is directed to resins made from resin acid,
fatty acid, phenolic compound and aldehyde, where the resins are
useful as, for example, binders in inks for lithographic and
gravure printing.
[0003] 2. Description of the Related Art
[0004] The use of rosin as a major component in the preparation of
binders for printing inks is very well known in the art. Such
rosin-based ink resins are used for a wide variety of printing
processes, including flexography, gravure printing, letterpress
printing, and lithography. Each printing process requires ink with
properties specific for that particular process, where relevant ink
properties include viscosity, solvent evaporation, wettability,
pigment dispersion, and compatibility with the other materials
present in the ink. In order to use rosin in inks having such a
diverse range of necessary performance properties, it is very
important to select the appropriate materials to react with the
rosin to form the ink binder. See, e.g., Roger F. Burke,
"Rosin-based Printing Inks," Naval Stores, Chapter 19, Pulp
Chemicals Association (1989).
[0005] A typical commercially available rosin-modified phenolic
resin is prepared from rosin, n-alkylphenol and paraformaldehyde,
where a polyol and optionally maleic anhydride may be included in
the reaction mixture. The following references describe some of the
rosin-based phenolic resins known in the art:
[0006] U.S. Pat. No. 6,172,174 (2001) and U.S. Pat. No. 5,969,071
(1999), to Matzinger, disclose phenolic rosin resins useful in
lithographic printing inks. The resins of Matzinger were prepared
without the addition of antifoaming agents and with a reduction in
the emission of aldehyde vapors compared to that commonly known in
the art.
[0007] European Patent No. EP 1 054 028 (2000), to Matzinger,
provides hydrocarbon/acrylic hybrid resins for adhesives, inks, and
coating compositions. Dicyclopentadiene is a necessary component
for the resin compositions disclosed.
[0008] U.S. Pat. No. 5,498,684 (1996), to Bender, provides
rosin-based phenolic resins as binders for ink formulations. The
Bender resins reportedly remain stable after at least six months of
continuous air exposure.
[0009] Production cost is an important consideration in the
preparation of rosin-based ink binders. It is well known to those
experienced in the art that the natural resins and resin acids
normally utilized in the production of printing inks are a
relatively expensive component of the ink binder. This expense is
further compounded by the realization that the global supply of
natural rosin is rapidly decreasing.
[0010] Potential future commercial regulations are another
important consideration in the preparation of rosin phenolic ink
binders. It is well-known in the art to incorporate alkylphenol,
particularly nonylphenol, as a component in preparing certain
rosin-based ink binders. However, recent literature provides
reports of possible adverse endocrine disruption effects to humans,
domesticated animals, and wildlife, resulting from the release of
nonylphenol and other alkylphenols into water sources (see, e.g.,
T. Sweeney, "Is Exposure to Endocrine Disrupting Compounds During
Fetal/Post-Natal Development Affecting the Reproductive Potential
of Farm Animals?" Domest Anim. Endocrinol., vol. 23, pp. 203-209
(2002); C. Sonnenschein and A. M. Soto, "An Updated Review of
Environmental Estrogen and Androgen Mimics and Antagonists," J.
Steroid Biochem. Mol. Biol., vol. 65, pp.143-150 (1998)). In
addition to the effect of these phenolic compounds on human and
animal health, these findings could ultimately cause the cost of
alkylphenols, and specifically nonylphenol, to increase
dramatically as commercial manufacturers move away from producing
these chemicals, thereby diminishing global supply. It is possible
that production of nonylphenol may even be banned altogether.
[0011] The present invention addresses the problems associated with
the use of alkylphenols in the preparation of rosin-containing ink
resins, and provides further related advantages as described
herein.
BRIEF SUMMARY OF THE INVENTION
[0012] In brief, the present invention is directed to new resins,
and the use of these resins in printing and coating processes.
These resins may be used for the preparation of varnishes, inks and
coatings, preferably equal to or superior in performance to those
in commerce today. The present invention also provides resins
formed from reactants perceived to be less hazardous to humans than
certain reactants typically used in the art.
[0013] In one aspect, the resins of the present invention are
prepared from resin acid, fatty acid, phenolic compound that is at
least trifunctional with respect to aldehyde reactivity, and
aldehyde. Rosin is both a suitable and preferred source for the
resin acids. Two preferred sources for fatty acid are tall oil
fatty acid (TOFA) and Monomer (a blend of fatty acids derived from
the fatty acid dimerization process). The reaction mixture may
optionally include .alpha.,.beta.-olefinically unsaturated carbonyl
compounds, e.g., .alpha.,.beta.-olefinically unsaturated carboxylic
acid(s) or anhydride(s), and/or polyol(s), as well as other
possible optional reactants. The resin may be dissolved in a
solvent to form a varnish, where the resin and/or varnish may be
used as a component of inks for lithographic or gravure
printing.
[0014] In one aspect, the present invention provides resin produced
by a process, the process comprising reacting reactants at elevated
temperature, the reactants comprising fatty acid, resin acid,
phenolic compound, and aldehyde. At least some of the phenolic
compound is trifunctional, that is, at least some of the phenolic
compound is capable of reacting with three moles of aldehyde per
mole of phenolic compound. Optionally, all of the phenolic compound
is trifunctional, where phenol is a preferred trifunctional
phenolic compound. As one alternative, the phenolic compound is a
mixture of phenolic compounds, where one of the phenolic compounds
is phenol. When the phenolic compound is a mixture of phenolic
compounds, then in various optional embodiments of the present
invention, the phenolic compound that is at least trifunctional
constitutes at least 5 wt %, or at least 10 wt %, or at least 15 wt
%, at least 20 wt %, or at least 25 wt %, or at least 30 wt %, or
at least 35 wt %, or at least 40 wt %, or at least 45 wt %, or at
least 50 wt %, or at least 55 wt %, or at least 60 wt %, or at
least 65 wt %, or at least 70 wt %, or at least 75 wt %, or at
least 80 wt %, or at least 85 wt %, or at least 90 wt %, or at
least 95 wt % of the total weight of the mixture of phenolic
compounds used to prepare the resin, where "or at least" in
reference to each of the wt % values is meant to include 100%.
[0015] In another aspect, the present invention provides a resin
produced by a process, where the process comprises reacting
reactants at elevated temperature, the reactants comprising resin
acid (e.g., rosin), fatty acid, phenolic compound, and aldehyde. In
this aspect of the invention, the fatty acid constitutes at least
30 wt % of the total weight of the resin-forming components. In
various embodiments, the fatty acid constitutes at least 32 wt %,
or at least 34 wt %, or at least 36 wt %, or at least 38 wt %, or
at least 40 wt %, or at least 42 wt %, or at least 44 wt %, or at
least 46 wt %, or at least 48 wt %, or at least 50 wt % of the
total weight of the resin-forming components. In various optional
embodiments, in addition to the specification of the amount of
fatty acid as set forth above, and for each of the specifications
of the amount of fatty acid as set forth above (i.e., for each of
30, 32, 34, 36 etc. wt %), the resin is additionally described by
the amount of trifunctional or greater phenolic compound that is
present among the reactants. In one embodiment, trifunctional or
greater phenolic compound is the only phenolic compound used to
form the resin. In related embodiments, phenolic compounds that are
trifunctional or higher constitutes at least 5 wt %, or at least 10
wt %, or at least 15 wt %, or at least 20 wt %, or at least 25 wt
%, or at least 30 wt %, or at least 35 wt %, or at least 40 wt %,
or at least 45 wt %, or at least 50 wt %, or at least 55 wt %, or
at least 60 wt %, or at least 65 wt %, or at least 70 wt %, or at
least 75 wt %, or at least 80 wt %, or at least 85 wt %, or at
least 90 wt %, or at least 95 wt % of the total weight of the
mixture of phenolic compounds. Phenol is a preferred trifunctional
or higher phenolic compound for use in this aspect and other
aspects of the present invention.
[0016] In another aspect, the present invention provides a resin
produced by a process, the process comprising taking reactants to
elevated temperature, the reactants comprising resin acid (e.g.,
rosin), fatty acid, phenolic compound, and aldehyde. In this aspect
of the invention, some or all of the fatty acid is Monomer. In one
embodiment, all of the fatty acid used to form the resin is
Monomer. In a related embodiment, the fatty acid is a mixture of
fatty acids, where at least some of that mixture comes from
Monomer. Optionally some, or all, of the phenolic compound is
trifunctional or higher, i.e., some, or all, of the phenolic
compound has at least three sites that are reactive with aldehyde.
In fact, in one embodiment, trifunctional or greater phenolic
compound is the only phenolic compound used to form the resin. In
related embodiments, trifunctional or greater phenolic compound
constitutes at least 5 wt %, or at least 10 wt %, or at least 15 wt
%, or at least 20 wt %, or at least 25 wt %, or at least 30 wt %,
or at least 35 wt %, or at least 40 wt %, or at least 45 wt %, or
at least 50 wt %, or at least 55 wt %, or at least 60 wt %, or at
least 65 wt %, or at least 70 wt %, or at least 75 wt %, or at
least 80 wt %, or at least 85 wt %, or at least 90 wt %, or at
least 95 wt % of the total weight of the mixture of phenolic
compounds. Phenol is a preferred phenolic compound having a
functionality of at least three with respect to reactivity with
aldehyde.
[0017] In another aspect, the present invention provides a resin
produced by a process, the process comprising exposing reactants to
elevated temperature, the reactants comprising fatty acid, resin
acid, phenolic compound, and aldehyde. In three separate
embodiments of this aspect of the invention, i) at least some of
the fatty acid is branched-chain monocarboxylic acid; ii) at least
some of the fatty acid is cyclic-chain fatty acid; iii) both
branched-chain fatty acid and cyclic-chain fatty acid are present
in the fatty acid. In a preferred embodiment, at least some of the
fatty acid is Monomer, where Monomer includes both branched-chain
fatty acid and cyclic-chain fatty acid. Again, in a preferred but
optional embodiment, some or all of the phenolic compound is at
least trifunctional with respect to reacting with aldehyde, e.g.,
some or all of the phenolic compound is phenol. For each of the
embodiments i), ii), and iii), the present invention optionally
provides that all of the phenolic compound used to form the resin
is at least trifunctional, where phenol is a preferred phenolic
compound that is at least trifunctional. In addition, for each of
the embodiments i), ii), and iii), the present invention optionally
provides that phenolic compound that is at least trifunctional
constitutes at least 5 wt %, or (in additional embodiments) at
least 10 wt %, or at least 15 wt %, or at least 20 wt %, or at
least 25 wt %, or at least 30 wt %, or at least 35 wt %, or at
least 40 wt %, or at least 45 wt %, or at least 50 wt %, or at
least 55 wt %, or at least 60 wt %, or at least 65 wt %, or at
least 70 wt %, or at least 75 wt %, or at least 80 wt %, or at
least 85 wt %, or at least 90 wt %, or at least 95 wt % of the
total weight of the mixture of phenolic compounds used to form the
resin.
[0018] In another aspect, the present invention provides a process
for preparing a resin, the process comprising reacting reactants at
elevated temperature, the reactants comprising rosin, fatty acid,
aldehyde and phenolic compound that is at least trifunctional with
respect to reactivity with aldehyde, wherein (a) the phenolic
compound that is at least trifunctional constitutes at least 25 wt
% of all phenolic compounds used to form the resin; and/or (b) the
fatty acid contributes at least 5% of the weight of the listed
reactants and the resin has a softening point that is equal to or
greater than the softening point of a corresponding resin wherein
some or all of the fatty acid is replaced with resin acid in the
rosin. Thus, the invention provides the process comprising reacting
reactants at elevated temperature, the reactants comprising rosin,
fatty acid, aldehyde and phenolic compound that is at least
trifunctional with respect to reactivity with aldehyde, wherein the
phenolic compound that is at least trifunctional constitutes at
least 25 wt % of all phenolic compounds used to form the resin. The
invention also provides the process comprising reacting reactants
at elevated temperature, the reactants comprising rosin, fatty
acid, aldehyde and phenolic compound that is at least trifunctional
with respect to reactivity with aldehyde, wherein the fatty acid
contributes at least 5% of the weight of the listed reactants and
the resin has a softening point that is equal to or greater than
the softening point of a corresponding resin wherein some or all of
the fatty acid is replaced with resin acid in the rosin.
[0019] In another aspect, the present invention provides a process
for preparing a resin, where the process comprises reacting
reactants at elevated temperature, and the reactants comprise resin
acid, fatty acid, aldehyde and phenolic compound that is at least
trifunctional with respect to reactivity with aldehyde. In this
aspect of the invention, the fatty acid contributes at least 5% of
the weight of the listed reactants, and the resin has a softening
point which is equal to or greater than the corresponding resin
prepared under the same circumstances except resin acid replaces
some or all of the fatty acid. In other words, the present
invention provides a resin-forming process wherein some of the
resin acid used in the preparation of a rosin-phenolic resin is
replaced by fatty acid, but the softening point of the resin is not
reduced, and may even be increased. In a related aspect, the
present invention provides a process for preparing a resin, where
the process comprises reacting reactants at elevated temperature,
and the reactants comprise resin acid, fatty acid, aldehyde and
phenolic compound that is at least trifunctional with respect to
reactivity with aldehyde. In this related aspect of the invention,
the fatty acid contributes at least 10% of the weight of the listed
reactants, and the resin has a softening point of at least
110.degree. C.
[0020] Optional reactants that may be included to prepare a resin
of the invention include .alpha.,.beta.-olefinically unsaturated
carbonyl compound, for example, maleic anhydride, and/or polyol,
for example, pentaerythritol. As stated above, a preferred phenolic
compound is phenol. A preferred aldehyde is paraformaldehyde.
Another optional resin-forming component is an alkaline metal salt,
e.g., an alkaline metal salt wherein the cation of said salt is
divalent. Suitable sources of resin acids for the invention include
tall oil rosin, gum rosin, wood rosin, and combinations thereof.
The resin acid or rosin may be pretreated, e.g., it may be
esterified or maleated, prior to being used in a resin-forming
reaction.
[0021] In another embodiment, the present invention provides a
lithographic ink resin produced by an improved process, the process
comprising reacting the reactants as described above, and elsewhere
herein, at elevated temperature so as to produce a lithographic ink
resin of the present invention.
[0022] In another embodiment, the present invention provides a
gravure ink resin produced by an improved process, the process
comprising reacting the reactants as described above, and elsewhere
herein, at elevated temperature so as to produce the gravure ink
resin of the present invention.
[0023] In another embodiment, the present invention provides a
varnish that includes a resin produced by the processes described
herein, and a suitable solvent. Suitable solvents are aromatic
hydrocarbons, e.g., benzene, toluene and xylene, and aliphatic
solvents such as heptane and naphtha. The varnish has a percent
resin solids, where that percentage is typically in the range of
25-50%, on weight basis.
[0024] In another aspect, the present invention provides a printing
ink comprising colorant, e.g., pigment, and a resin of the present
invention, optionally formulated for gravure or lithographic
printing.
[0025] Thus, the present invention provides a process for forming a
resin from reactants, the reactants comprising fatty acid, resin
acid, aldehyde and phenolic compound that is at least trifunctional
with respect to aldehyde reactivity. The process comprising
maintaining the reactants at elevated temperature for a time
sufficient to form the resin. In a preferred embodiment, the
phenolic compound that is at least trifunctional constitutes at
least 25 wt % of all phenolic compounds used to form the resin, or
the fatty acid contributes at least 5% of the weight of the listed
reactants and the resin has a softening point of at least
105.degree. C.
[0026] These and other aspects of this invention will become
apparent upon reference to the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention provides for the preparation of resins
useful as binders in printing inks. As used herein, the term
"binder" refers to the product(s) of the reactions described
herein. These products will have higher molecular weight than the
starting materials, and may also be referred to as polymers. These
resin/polymer products are particularly useful in inks and
coatings, where they serve one or more functions, for example, as
agents that wet, disperse and/or stabilize pigment, or as agents
that adhere pigment to the printed substrate. They may also, or
alternatively, be included in ink in order to provide compatibility
between two or more other ingredients of the ink. The binder may
provide film-forming properties and improve, for example, the gloss
of the printed product. These are some exemplary reasons why a
binder of the present invention may be included in an ink or
coating formulation.
[0028] In one aspect, the resins of the present invention are
characterized in terms of the process by which they are made. In
particular, the resins are characterized in terms of the reactants
that are reacted together to form the product resin. It has been
surprisingly discovered that resins with excellent solubility in
aliphatic solvents can be prepared by including both highly
reactive phenolic compounds and fatty acid in a formulation to
prepare a resin acid-modified phenolic resin. In another aspect, it
has also been surprisingly discovered that the use of highly
branched or cyclic fatty acid along with resin acid, phenolic
compound and aldehyde, can advantageously be employed in the
preparation of a resin. In a preferred embodiment of the invention,
a resin is produced from both highly reactive phenolic compound and
branched/cyclic fatty acid, in combination with resin acid and
aldehyde.
[0029] As discussed in further detail below, resin acid-modified
phenolic resins may be prepared by reacting together resin acid,
fatty acid, tri- or higher-functional phenolic compound and
aldehyde. The fatty acid may be Monomer (derived from the fatty
acid dimerization process). The reaction mixture may optionally
include .alpha.,.beta.-olefinically unsaturated carboxylic acid(s)
or anhydride(s), and polyol(s). The resin may be dissolved in a
solvent to form a varnish. The varnish may be used as a component
of inks for lithographic or gravure printing.
[0030] In describing the present invention, it should be understood
that the word "a" refers to one or more of the indicated objects.
For example, "a resin acid" refers to one or more resin acids,
where resin acids may differ in terms of, e.g., their exact
structure. Likewise, "a rosin" refers to one or more types of
rosin, e.g., wood rosin, gum rosin, tall oil rosin, etc. Also,
because the resins of the present invention are particularly useful
as binders in ink formulations, the resins of the invention may be
referred to herein as "binders". It should be noted that the term
"binder" is sometimes used to refer to the resin per se, where the
term "binder" is not to be construed as a limitation on the use of
the resin or a statement of resin properties.
[0031] A. Reactants
[0032] In one aspect, the resin of the present invention is
prepared from reactants that include fatty acid, resin acid,
aldehyde, and phenolic compound, with at least one of the following
criteria being met:
[0033] a) the fatty acid comprises branched-chain fatty acid;
[0034] b) the fatty acid comprises cyclic-chain fatty acid; and
[0035] c) the phenolic compound is, or includes, phenolic compounds
that are at least tri-functional in terms of reactivity with
aldehyde or reactive equivalents thereof.
[0036] Thus, in seven different and distinct aspects of the
invention, the resin is prepared from resin acid, fatty acid,
phenolic compound and aldehyde, such that a); or such that b); or
such that c); or such that a) and b); or such that a) and c); or
such that b) and c); or such that a) and b) and c), where each of
a), b) and c) is defined above. As discussed in detail elsewhere
herein, in various embodiments of the invention, it may be further
required that a minimum amount of a specified component is present
among the reactants, and/or that a specific resin (or varnish or
ink) property is present in the resin.
[0037] Before further describing the resin of the invention and the
process by which it may be prepared, each of the necessary
reactants, and many optional reactants, will be described.
[0038] 1. Resin Acid
[0039] Resin acids is a term of art that is used to refer to
monocarboxylic diterpene acids, see, e.g., Simonsen, J.; Barton, D.
H. R., The Terpenes, Vol. III, Cambridge University Press,
Cambridge (1952); and Hanson, J. R., Natural Prod. Reports 5:211
(1988). Two common types of resin acid are the abietane-type and
pimarane/isopimarane-type resin acids which each has three
connecting six-membered rings. The labdane-type resin acids are
another well known class of resin acid, where labdane resin acids
have two fused six-membered rings. Exemplary resin acids include,
without limitation, abietic acid (CAS # 514-10-3, see structure (1)
below); communic acid (CAS # 1231-35-2); dehydroabietic acid (CAS #
1740-19-8); isopimaric acid (CAS # 5835-26-7); levopimaric acid
(CAS # 79-54-9); neoabietic acid (CAS # 471-77-2); palustric acid
(CAS # 1945-53-5); pimaric acid (CAS # 127, 27-5, see structure (2)
below); and sandaracopimaric acid (CAS # 471-74-9). 1
[0040] Resin acids were initially discovered as a component of
plants, and are commonly obtained today from pine trees. Exemplary
sources of resin acids that may be used in the practice of the
present invention are provided below.
[0041] As used herein, the term "resin acid" includes the
monocarboxylic diterpene acids that are commonly known as resin
acids from, e.g., Simonsen, J.; Barton, D. H. R., The Terpenes,
Vol. III, Cambridge University Press, Cambridge (1952). In one
aspect, the resin acid used in preparing the binder of the present
invention is a mixture of these monocarboxylic diterpene acids,
optionally in admixture with other materials, as obtained from
trees.
[0042] The resin acid, or resin acid-containing material (e.g.,
rosin), may be pre-treated or pre-reacted prior to being used with
fatty acid, phenolic compound and aldehyde in a resin-forming
reaction of the present invention. Accordingly, as used herein, the
terms "resin acid" and "rosin" will include derivatives and
reaction products of these monocarboxylic diterpene acids, as
exemplified and discussed briefly below. The term "resin acid" is
also intended to include compositions that contain some resin acid.
In various optional embodiments, the resin acid-containing
composition contains, on a weight percent basis, at least 10%, or
at least 20%, or at least 30%, or at least 40%, or at least 50%, or
at least 60%, or at least 70%, or at least 75%, or at least 80%, or
at least 85%, or at least 90%, or at least 95% resin acids. Further
details regarding resin acid derivatives and reaction products may
be found in, e.g., Soltes, E. J. and Zinkel, D. F. "Chemistry of
Rosin" Chap 9 of Naval Stores, Zinkel, D. F. and Russell, J. eds.,
Pulp Chemicals Association, New York, N.Y., 1989.
[0043] a. Salts
[0044] The carboxylic acid group of a resin acid may be converted
into a salt form. These salt forms are considered a "resin acid"
according to the present invention, and may be specifically
referred to herein as resin acid salts. Exemplary counterions in a
resin acid salt include, without limitation, monovalent and
divalent metals, e.g., the cations of sodium, potassium, zinc,
magnesium and calcium. Sources for these counterions include,
without limitation, calcium oxide, calcium hydroxide, magnesium
oxide and magnesium hydroxide. Methods of neutralizing a resin acid
with a metal salt, metal oxide, or the like so as to form resin
acid salt are well known in the art. The products of such reactions
are sometimes referred to as resin acid soaps. The resin acid may
be present within rosin, and accordingly rosin soaps are a source
of resin acid soap according to the present invention. Also, rosin
soaps are considered a "rosin" of the present invention.
[0045] b. Esters
[0046] The carboxylic acid group of a resin acid may participate in
an esterification reaction so as to be converted into an ester.
Esters of resin acids are "resin acids" according to the present
invention, and may be specifically referred to herein as resin acid
esters. The resin acid may be reacted with a monohydric or
polyhydric (polyol) molecule to convert the carboxylic acid into a
carboxylate ester.
[0047] Exemplary monohydric molecules include, without limitation,
methanol, ethanol, propanol, butanol, and 2-ethylhexanol.
[0048] Exemplary polyhydric molecules, also known as polyols,
include, without limitation, C.sub.2-C.sub.36 dihydric compounds,
C.sub.3-C.sub.36 trihydric compounds, C.sub.5-C.sub.36 tetrahydric
compounds, C.sub.5-C.sub.36 pentahydric compounds and
C.sub.6-C.sub.36 hexahydric compounds. Specific polyols include,
without limitation, ethylene glycol, propylene glycol, diethylene
glycol, triethylene glycol, butanediol, glycerol,
trimethylolpropane, triethyloipropane, pentaerythritol, and
carbohydrate derived-polyhydric molecules such as dimerized
trimethylolpropane and dimerized pentaerythritol. When resin acids
are esterified with polyols, one or more of the hydroxyl groups of
the polyol may enter into an esterification reaction, i.e., a resin
acid ester may, or may not, contain residual hydroxyl groups from
the polyol.
[0049] A type of resin acid ester is known in the art as an alkyd
resin. Alkyd resins may be prepared by reaction of resin acid,
fatty acid triglyceride, diacid (e.g., isophthalic acid) and polyol
(e.g., glycerin). There are numerous other alkyd formulations that
use resin acid as an alkyd-forming reactant, where these alkyds are
referred to herein as resin acid alkyds. Resin acid alkyds are a
"resin acid" as that term is used herein.
[0050] The resin acid may be present in rosin, and accordingly
rosin esters are a source of resin acid ester according to the
present invention. Also, rosin esters are considered a "rosin" of
the present invention. Methods to esterify rosin and resin acids
with mono- and polyhydric compounds are well known in the art.
[0051] c. Adducts
[0052] Resin acids may undergo Diels-Alder and/or ene-type
reactions with .alpha.,.beta.-olefinically unsaturated carbonyl
compounds, where these reaction products will be referred to herein
as resin acid adducts. Resin acid adducts are included within the
scope of the term "resin acid" as used herein.
[0053] Exemplary .alpha.,.beta.-olefinically unsaturated carbonyl
compounds include, without limitation, maleic anhydride, fumaric
acid, mono (C.sub.1-C.sub.12alkyl) ester of fumaric acid,
di(C.sub.1-C.sub.12alkyl) ester of fumaric acid, acrylic acid,
C.sub.1-C.sub.12alkyl ester of acrylic acid, methacrylic acid,
C.sub.1-C.sub.12alkyl ester of methacrylic acid, itaconic acid, and
C.sub.1-C.sub.12alkyl ester of itaconic acid. As used herein,
"alkyl" refers to a monovalent hydrocarbon radical group (i.e., a
hydrocarbyl monovalent radical) containing exclusively C--C and
C--H single bonds, while "hydrocarbon" refers to any molecular
structural domain containing exclusively carbon and hydrogen atoms;
"alkenyl" refers to a hydrocarbyl monovalent radical containing at
least one C.dbd.C double bond, while "alkynyl" refers to a
hydrocarbyl monovalent radical containing at least one C.ident.C
triple bond.
[0054] Rosin may serve as the source of the resin acid, where rosin
adducts are sources of resin acid adducts of the present invention.
Rosin adducts will be considered within the scope of the terms
"rosin" and "resin acid". The adduction reaction between resin acid
(e.g., rosin) and .alpha.,.beta.-olefinically unsaturated carbonyl
compound is well known in the art, and can be made to occur by
heating resin acid and .alpha.,.beta.-olefinically unsaturated
carbonyl compounds to a reaction-forming temperature, e.g., about
150.degree. C.
[0055] d. Dimers
[0056] Under acid conditions and elevated temperatures, resin acids
react with themselves to form dimerization products. Some
trimerization, etc. reaction also occurs during this dimerization
process, but typically dimerized product forms to the greatest
extent. The action of strong heat and/or strong acids on resin acid
is sometimes referred to as "polymerization" of resin acids. The
product(s) from this reaction will be referred to herein as resin
acid dimers, where resin acid dimers are a "resin acid" of the
present invention. Rosin may provide the source for the resin acid.
In this case, polymerized rosin may provide the source of the
polymerized resin acid. Also, polymerized rosin is considered
within the scope of the term "rosin" as used herein.
[0057] e. Isomers
[0058] Resin acids may be exposed to various reaction conditions
that yield isomerized resin acids. An isomerized resin acid has,
e.g., a different configuration of double bonds than did the
original resin acid. Temperature and/or acid (for example a Lewis
or Br.o slashed.nsted acid) are suitable conditions for achieving
resin acid isomerization. Upon exposure to isomerization
conditions, resin acids that are not otherwise naturally occurring
may be produced, however, isomerization conditions can also convert
a resin acid from one naturally occurring structure to another
naturally-occurring structure. Isomer(s) that result from exposure
of resin acid to isomerization conditions produces resin acid
isomers that are within the scope of the term "resin acid" as used
herein. Reaction conditions to achieve resin acid isomerization are
well known in the art. Rosin may provide the source of the resin
acid. In this case, isomerized rosin may provide the source of the
isomerized resin acid. Isomerized rosin is considered within the
scope of the term "rosin" as used herein.
[0059] f. Hydrogenation
[0060] Resin acid may be exposed to hydrogen gas in order to reduce
the double bond(s) present in the acid. Typically a catalyst, such
as palladium on carbon or Raney nickel, along with elevated
temperature and pressure, is utilized to achieve the efficient
hydrogenation of a resin acid. The reaction product(s) from
hydrogenation of resin acid will be referred to herein as
hydrogenated resin acid, where hydrogenated resin acid is a "resin
acid" within the meaning of that term as used herein. Hydrogenation
of resin acid is well known in the art.
[0061] Although hydrogenated resin acid, e.g., hydrogenated rosin,
may be used in the practice of the present invention, it is
preferred that not all of the resin acid be completely saturated.
The presence of unsaturation in the resin acid is considered
desirable in order to allow reaction to occur between the resin
acid and phenolic compound and/or aldehyde and/or the reaction
product there between. Accordingly, if hydrogenated resin acid or
rosin is utilized in the practice of the present invention, some
unsaturated resin acid or rosin is also preferably present in the
reaction mixture.
[0062] Hydrogenation can, however, be applied to the reaction
product of resin acid+fatty acid+aldehyde+phenolic compound.
Hydrogenation of this reaction product tends to increase the
stability of the resin, where increased resin stability is
particularly important is non-pigmented products, e.g., overprint
varnishes. Accordingly, in one aspect, the present invention
provides an overprint varnish comprising a resin of the present
invention, where the resin has been optionally post-treated by
hydrogenation. In addition, the present invention provides a resin,
and a process for its preparation, wherein resin acid+fatty
acid+aldehyde+phenolic compound as described herein are reacted to
form a resin, and the resin is post-treated by hydrogenation.
[0063] g. Dehydrogenation/Disproportionation
[0064] Many resin acids have two double bonds. Transfer of hydrogen
from one resin acid to another resin acid, so as to provide resin
acids with zero and three double bonds, respectively, is referred
to as dehydrogenation/disproportionation. Typically a metal on
carbon catalyst, where the metal may be, e.g., palladium, platinum
or nickel, is used to facilitate the
dehydrogenation/disproportionation reaction. However, other
reaction conditions to facilitate
dehydrogenation/disproportionatio- n of resin acid are also known
in the art. The product(s) from this reaction may be referred to as
disproportionated resin acid, where these product(s) are a "resin
acid" within the meaning of this term as used herein. However, it
is preferred that disproportionated resin acids not be the only
resin acids present in the resin-forming reaction mixtures of the
present invention.
[0065] The foregoing are exemplary of rosin and resin acid
derivatives and reaction products that are included within the
scope of the terms "rosin" and "resin acid" respectively as used
herein. The present invention provides resinous binders for
printing inks that are prepared from resin acid, fatty acid, phenol
and aldehyde. So long as the resin acid derivative is still
reactive with phenol and aldehyde, it may be included within the
scope of the term "resin acid" as that term is used herein. The
term "natural resin acid" will be used to refer to a resin acid
that is naturally occurring or found in untreated or unmodified
rosin, e.g., abietic acid, communic acid, dehydroabietic acid,
isopimaric acid, levopimaric acid, neoabietic acid, palustric acid,
pimaric acid, sandaracopimaric acid, etc. The term "natural rosin"
will be used to refer to rosin that has not been chemically
modified or treated.
[0066] The resin acid typically contributes 1-85 wt % of the total
weight of the reactants used to form the resin of the present
invention. In optional embodiments, resin acid contributes up to 85
wt %, or up to 80 wt %, or up to 75 wt %, or up to 70 wt %, or up
to 65 wt %, or up to 60 wt %, or 10-85 wt %, or 10-80 wt %, or
10-75 wt %, or 10-70 wt %, or 10-65 wt %, 10-60 wt %, or 20-85 wt
%, or 20-80 wt %, or 20-75 wt %, or 20-70 wt %, or 20-65 wt %, or
20-60 wt %, or 25-85 wt %, or 25-80 wt %, or 25-75 wt %, or 25-70
wt %, or 25-65 wt %, or 25-60 wt %, or 30-85 wt %, or 30-80 wt %,
or 30-75 wt %, or 30-70 wt %, or 30-65 wt %, or 30-60 wt %, or
35-85 wt %, or 35-80 wt %, or 35-75 wt %, or 35-70 wt %, or 35-65
wt %, or 35-60 wt %, or 40-85 wt %, or 40-80 wt %, or 40-75 wt %,
or 40-70 wt %, or 40-65 wt %, or 40-60 wt %, or 45-85 wt %, or
45-80 wt %, or 45-75 wt %, or 45-70 wt %, or 45-65 wt %, or 45-60
wt % of the total weight of the reactants used to form a resin of
the invention.
[0067] In a preferred embodiment, rosin is used as the source of
resin acids, and rosin contributes up to 85 wt %, or up to 80 wt %,
or up to 75 wt %, or up to 70 wt %, or up to 65 wt %, or up to 60
wt %, or 10-85 wt %, or 10-80 wt %, or 10-75 wt %, or 10-70 wt %,
or 10-65 wt %, 10-60 wt %, or 20-85 wt %, or 20-80 wt %, or 20-75
wt %, or 20-70 wt %, or 20-65 wt %, or 20-60 wt %, or 25-85 wt %,
or 25-80 wt %, or 25-75 wt %, or 25-70 wt %, or 25-65 wt %, or
25-60 wt %, or 30-85 wt %, or 30-80 wt %, or 30-75 wt %, or 30-70
wt %, or 30-65 wt %, or 30-60 wt %, or 35-85 wt %, or 35-80 wt %,
or 35-75 wt %, or 35-70 wt %, or 35-65 wt %, or 35-60 wt %, or
40-85 wt %, or 40-80 wt %, or 40-75 wt %, or 40-70 wt %, or 40-65
wt %, or 40-60 wt %, or 45-85 wt %, or 45-80 wt %, or 45-75 wt %,
or 45-70 wt %, or 45-65 wt %, or 45-60 wt % of the total weight of
the reactants used to form a resin of the invention.
[0068] In a preferred embodiment, the resin acid contributes about
45-60 wt % of the total weight of the reactants used to form the
resin. In another preferred embodiment rosin serves as the source
of resin acids and rosin contributes about 45-60 wt % of the total
weight of the reactants.
[0069] 2. Fatty Acid
[0070] The term "fatty acid" refers to chemicals of the formula
R.sup.1--COOH, as well as derivatives and analogs thereof, where
R.sup.1 is a hydrocarbon group of at least six carbons. The term
hydrocarbon refers to any molecular structure containing only
hydrogen and carbon atoms. The hydrocarbon group may be saturated
(i.e., contains no double or triple carbon-carbon bonds) or
unsaturated (i.e., contains at least one double or triple
carbon-carbon bond), with no limitation on the number of
unsaturations. R.sup.1 may independently be characterized by its
hydrocarbon chain configuration as linear, branched, or cyclic, and
may also be characterized in terms of the number of carbons present
in the R.sup.1 group.
[0071] In various aspect of the invention, the fatty acid includes,
to the extent of at least 50 wt %, or at least 60 wt %, or at least
70 wt %, or at least 80 wt %, or at least 90 wt %, based on the
total weight of fatty acid, or is exclusively comprised of, fatty
acids that have 12-28, or 14-28, or 16-28, or 18-28, or 12-22, or
14-22, or 16-22, or 18-22, or 12-20, or 14-20, or 16-20, or 18-20
carbon atoms. Optionally, the fatty acid is a liquid at room
temperature, or has a melting point below 100.degree. C. Optionally
the fatty acid is a mixture of fatty acid structures, e.g., TOFA
and Monomer.
[0072] Although the terms "linear", "branched" and "cyclic" are
well known to one of ordinary skill in the art, for additional
clarity illustrative examples of a C8 fatty acid (i.e., a fatty
acid having a total of 8 carbons) having a linear-(structure (1)),
branched-(structure (2)) and cyclic-(structure (3)) chain
hydrocarbon group are shown below: 2
[0073] Fatty acids wherein R.sup.1 is a chain of at least 14 carbon
atoms are frequently known as "long-chain monocarboxylic acids" or
"long-chain fatty acids." In one aspect of the present invention,
the fatty acid used to prepare a resin of the invention is, or
includes, long-chain fatty acid. Exemplary long-chain fatty acids
include saturated acids such as, without limitation, capric,
lauric, myristic, palmitic, stearic, hydroxystearic, and arachidic
acids; and unsaturated acids such as, without limitation, oleic,
linoleic, linolenic, and arachidonic acids; and mixtures thereof.
In a preferred embodiment, the cyclic fatty acid has a single ring,
such as shown in structure (3) above. However, the cyclic fatty
acid may also include a branch point in the chain. In a preferred
embodiment, the branched chain fatty acid is acyclic. In a
preferred aspect, the fatty acid reactant includes branched-chain
fatty acid, or cyclic-chain fatty acid, or a combination of
branched-chain and cyclic-chain fatty acids. In an optional aspect,
the fatty acid reactant further comprises linear-chain fatty
acid.
[0074] The fatty acid may be a derivative or analog of the
chemicals of the formula R.sup.1--COOH. A fatty acid analog refers
to compounds wherein one or more atoms are replaced with different
atoms, but the resulting compound still has the ability to provide
fatty character to the resin. For example, hydroxyl-substituted
fatty acids are fatty acid analogs, where ricinoleic acid (also
known as 12-hydroxystearic acid) is an example of this type of
fatty acid analog.
[0075] Fatty acid derivatives are fatty acids that have undergone
some sort of chemical treatment which changes the chemical
structure of the fatty acid, however the product of this chemical
treatment still has the ability to provide fatty character to a
resin of the present invention. The following are exemplary fatty
acid derivatives.
[0076] a. Salts
[0077] The carboxylic acid group of a fatty acid may be converted
into a salt form. These salt forms are considered a "fatty acid"
according to the present invention, and may be specifically
referred to herein as fatty acid salts. Exemplary counterions in a
fatty acid salt include, without limitation, sodium, potassium,
zinc, magnesium and calcium. Sources for these counterions include,
without limitation, calcium oxide, calcium hydroxide, magnesium
oxide and magnesium hydroxide. Methods of neutralizing a fatty acid
with a metal salt, metal oxide, or the like so as to form fatty
acid salt are well known in the art. The products of such reactions
are sometimes referred to as fatty acid soaps.
[0078] b. Esters
[0079] The carboxylic acid group of a fatty acid may participate in
an esterification reaction so as to be converted into an ester.
Esters of fatty acids are "fatty acids" according to the present
invention, and may be specifically referred to herein as fatty acid
esters. The fatty acid may be reacted with a monohydric or
polyhydric (polyol) molecule to convert the carboxylic acid into a
carboxylate ester.
[0080] Exemplary monohydric molecules include, without limitation,
methanol, ethanol, propanol, butanol, and 2-ethylhexanol.
[0081] Exemplary polyhydric molecules, also known as polyols,
include, without limitation, C.sub.2-C.sub.36 dihydric compounds,
C.sub.3-C.sub.36 trihydric compounds, C.sub.5-C.sub.36 tetrahydric
compounds, C.sub.5-C.sub.36 pentahydric compounds and
C.sub.6-C.sub.36 hexahydric compounds. Specific polyols include,
without limitation, ethylene glycol, propylene glycol, diethylene
glycol, triethylene glycol, butanediol, glycerol,
trimethylolpropane, triethylolpropane, pentaerythritol,
carbohydrate, dimerized trimethylolpropane, and dimerized
pentaerythritol. When fatty acids are esterified with polyols, one
or more of the hydroxyl groups of the polyol may enter into an
esterification reaction, i.e., a fatty acid ester may, or may not,
contain residual hydroxyl groups from the polyol. Accordingly, a
"fatty acid" of the present invention may contain some hydroxyl
groups.
[0082] Methods to esterify fatty acids with mono- and polyhydric
compounds are well known in the art. Many fatty acid esters,
especially triglycerides, are known in the art and are commercially
available. In fact, many triglycerides are naturally occurring oils
and fats. Examples include peanut oil, tallow, castor oil, palm
oil, olive oil, rapeseed oil, soybean oil, sunflower oil and
linseed oil.
[0083] c. Adducts
[0084] Unsaturated fatty acids may undergo Diels-Alder and/or
ene-type reactions with .alpha.,.beta.-olefinically unsaturated
carbonyl compounds, where these reaction products will be referred
to herein as fatty acid adducts. Fatty acid adducts are included
within the scope of the term "fatty acid" as used herein. Exemplary
.alpha.,.beta.-olefinical- ly unsaturated carbonyl compounds
include, without limitation, maleic anhydride, fumaric acid, mono
(C.sub.1-C.sub.12alkyl) ester of fumaric acid,
di(C.sub.1-C.sub.12alkyl) ester of fumaric acid, acrylic acid,
C.sub.1-C.sub.12alkyl ester of acrylic acid, methacrylic acid,
C.sub.1-C.sub.12alkyl ester of methacrylic acid, itaconic acid, and
C.sub.1-C.sub.12alkyl ester of itaconic acid. The adduction
reaction between fatty acid and .alpha.,.beta.-olefinically
unsaturated carbonyl compound is well known in the art.
[0085] d. Dimers
[0086] Under acid conditions and elevated temperatures, fatty acids
react with themselves to form dimerization products. Some
trimerization, etc. reaction also occurs during this dimerization
process, but typically dimerized product forms to the greatest
extent. The action of strong heat and/or strong acids on fatty acid
is often referred to as polymerization of fatty acids. The
product(s) from this reaction are commonly referred to as dimer
acid, or more simply as dimer. Dimer acid is a "fatty acid" of the
present invention. A by-product of this polymerization process is
called Monomer, where Monomer is a mixture of fatty acids. In one
aspect, Monomer provides some or all of the fatty acid used to form
a resin of the present invention.
[0087] e. Isomers
[0088] Unsaturated fatty acids may be subjected to various reaction
conditions that yield isomerized fatty acids. An isomerized fatty
acid has, e.g., a different configuration of double bonds than did
the original fatty acid. Temperature and/or acid (for example Lewis
or Br.o slashed.nsted acid) are suitable conditions for achieving
fatty acid isomerization. Isomer(s) that result from exposure of
fatty acid to isomerization conditions produces fatty acid isomers
that are within the scope of the term "fatty acid" as used herein.
Reaction conditions to achieve fatty acid isomerization are well
known in the art.
[0089] f. Hydrogenation
[0090] Unsaturated fatty acid may be exposed to hydrogen gas in
order to reduce the double bond(s) present in the acid. Typically a
catalyst, such as palladium on carbon or Raney nickel, along with
elevated temperature and pressure, is utilized to achieve the
efficient hydrogenation of a fatty acid. The reaction product(s)
from hydrogenation of unsaturated fatty acid will be referred to
herein as saturated fatty acid, where both saturated and
unsaturated fatty acids are "fatty acid" within the meaning of that
term as used herein. Hydrogenation of fatty acid is well known in
the art.
[0091] The term "fatty acid" is also intended to include
compositions that contain some fatty acid. In various optional
embodiments, the fatty acid-containing composition contains, on a
weight percent basis, at least 10%, or at least 20%, or at least
30%, or at least 40%, or at least 50%, or at least 60%, or at least
70%, or at least 75%, or at least 80%, or at least 85%, or at least
90%, or at least 95% fatty acids.
[0092] In various aspects of the present invention, fatty acid
contributes up to 85 wt %, or up to 75 wt %, or up to 65 wt %, or
up to 50 wt %, or up to 40 wt %, or up to 30 wt %, or up to 25 wt
%, or 1-85 wt %, or 1-75 wt %, or 1-65 wt %, or 1-50 wt %, or 1-40
wt %, 1-30 wt %, or 1-25 wt %, or 5-65 wt %, or 5-50 wt %, or 5-40
wt %, 5-30 wt %, or 5-25 wt %, or 10-65 wt %, or 10-50 wt %, or
10-40 wt %, 10-30 wt %, or 10-25 wt %, or 15-65 wt %, or 15-50 wt
%, or 15-40 wt %, 15-30 wt %, or 15-25 wt %, of the total weight of
the resin-forming composition, where for each of these ranges,
Monomer may be all of the fatty acid, or may be any fraction of the
fatty acid as set forth in the previous paragraph. In a preferred
embodiment, fatty acid constitutes about 15-25 wt % of the total
weight of the reactants used to form the resin.
[0093] In one aspect of the invention, the weight of resin acids,
or the weight of rosin, exceeds the weight of fatty acid in the
reaction mixture. In general, as the level of fatty acid increases
in proportion to the level of resin acid, the resulting resin tends
to have a lower softening point. Accordingly, in various optional
embodiments of the invention, the weight of resin acids, or the
weight of rosin, is at least 10% greater, or at least 20% greater,
or at least 30% greater, or at least 40% greater, or at least 50%
greater, or at least 60% greater, or at least 70% greater, or at
least 80% greater, or at least 90% greater, or at least 100%
greater than the weight of fatty acid present in the reaction
mixture. In other optional embodiments, resin acid contributes at
least 50%, or at least 55%, or at least 60%, or at least 65%, or at
least 70%, or at least 75%, or at least 80%, or at least 85%, or at
least 90%, or at least 95% of the total weight of resin acid and
fatty acid utilized to prepare a resin. In an optional embodiment,
rosin contributes 50-95%, and fatty acid contributes 5-50% of the
total weight of fatty acid and resin acid used to prepare a resin
of the invention. In another optional embodiment, rosin contributes
60-90%, and fatty acid contributes 10-40% of the total weight of
fatty acid and resin acid used to prepare a resin of the invention.
In another optional embodiment, rosin contributes 65-85%, and fatty
acid contributes 15-35% of the total weight of fatty acid and resin
acid used to prepare a resin of the invention.
[0094] In general, the reaction mixture should contain significant
amounts of both resin acids and fatty acids. In various optional
embodiments of the invention, when rosin serves as the source of
resin acids, and ignoring any fatty acids that may be present in
the rosin, fatty acid constitutes at least 5 wt % of the total
weight of the reactants when rosin contributes, in various
embodiments, at least 30 wt %, or at least 35 wt %, or at least 40
wt %, or at least 45 wt %, or at least 50 wt %, or at least 55 wt
%, or at least 60 wt %, or at least 65 wt %, or at least 70 wt %,
or at least 75 wt % of the total weight of the resin-forming
reactants. In various additional optional embodiments of the
invention, when rosin serves as the source of resin acids, and
ignoring any fatty acids that may be present in rosin, fatty acid
constitutes at least 10 wt % of the total weight of the reactants
when rosin contributes, in various embodiments, at least 30 wt %,
or at least 35 wt %, or at least 40 wt %, or at least 45 wt %, or
at least 50 wt %, or at least 55 wt %, or at least 60 wt %, or at
least 65 wt %, or at least 70 wt %, or at least 75 wt % of the
total weight of the resin-forming reactants.
[0095] The fatty acid provides aliphatic character to the resin. In
other words, including fatty acid among the reactants increases the
aliphatic solvent compatibility of the resulting resin. While this
is generally a desirable result, a second effect of including fatty
acid among the reactants is that the softening point of the resin
tends to decrease. For many commercial applications, the softening
point of the resin should be at least about 100.degree. C., and
often a higher softening point is even more desirable, e.g., at
least 105.degree. C., or at least 110.degree. C., or at least
120.degree. C., or at least 130.degree. C., etc. In one aspect, the
present invention surprisingly provides that a significant amount
of fatty acid can be included among the reactants while still
maintaining a commercially desirable softening point.
[0096] Thus, in one aspect, the present invention provides a
process for preparing a resin, the process comprising reacting
reactants at elevated temperature, the reactants comprising resin
acid, fatty acid, aldehyde and phenolic compound that is at least
trifunctional with respect to reactivity with aldehyde, where the
fatty acid contributes at least 5% of the weight of the listed
reactants, and the resin has a softening point which is equal to or
greater than the corresponding resin prepared wherein resin acid
replaces some or all of the fatty acid. In other words, the present
invention provides a resin-forming process wherein some of the
resin acid used in the preparation of a rosin-phenolic resin is
replaced by fatty acid, but the softening point of the resin is not
reduced, and may even be increased. This maintenance of softening
point is achieved by including phenol compound that is at least
tri-functional with respect to aldehyde reactivity, among the
resin-forming reactants. From a practical point of view this is a
very important discovery because fatty acid is much less expensive,
and much more available, than resin acid.
[0097] Thus, in one aspect the present invention provides:
[0098] (i) A process for preparing a resin, the process comprising
reacting reactants at elevated temperature, the reactants
comprising resin acid, fatty acid, aldehyde and phenolic compound
that is at least trifunctional with respect to reactivity with
aldehyde, where the fatty acid contributes at least 5% of the
weight of the listed reactants, and the resin has a softening point
which is equal to or greater than the corresponding resin prepared
wherein resin acid replaces some or all of the fatty acid.
[0099] In various additional aspects the invention also
provides:
[0100] (ii) A process for preparing a resin, the process comprising
reacting reactants at elevated temperature, the reactants
comprising resin acid, fatty acid, aldehyde and phenolic compound
that is at least trifunctional with respect to reactivity with
aldehyde, where the fatty acid contributes at least 5% of the
weight of the listed reactants, and the resin has a softening point
of at least 105.degree. C.
[0101] (iii) A process for preparing a resin, the process
comprising reacting reactants at elevated temperature, the
reactants comprising resin acid, fatty acid, aldehyde and phenolic
compound that is at least trifunctional with respect to reactivity
with aldehyde, where the fatty acid contributes at least 10% of the
weight of the listed reactants, and the resin has a softening point
of at least 110.degree. C.
[0102] (iv) A process for preparing a resin, the process comprising
reacting reactants at elevated temperature, the reactants
comprising resin acid, fatty acid, aldehyde and phenolic compound
that is at least trifunctional with respect to reactivity with
aldehyde, where the fatty acid contributes at least 15% of the
weight of the listed reactants, and the resin has a softening point
of at least 110.degree. C.
[0103] (v) A process for preparing a resin, the process comprising
reacting reactants at elevated temperature, the reactants
comprising resin acid, fatty acid, aldehyde and phenolic compound
that is at least trifunctional with respect to reactivity with
aldehyde, where the fatty acid contributes at least 5% of the
weight of the listed reactants, and the resin has a softening point
of at least 120.degree. C.
[0104] (vi) A process for preparing a resin, the process comprising
reacting reactants at elevated temperature, the reactants
comprising resin acid, fatty acid, aldehyde and phenolic compound
that is at least trifunctional with respect to reactivity with
aldehyde, where the fatty acid contributes at least 10% of the
weight of the listed reactants, and the resin has a softening point
of at least 120.degree. C.
[0105] (vii) A process for preparing a resin, the process
comprising reacting reactants at elevated temperature, the
reactants comprising resin acid, fatty acid, aldehyde and phenolic
compound that is at least trifunctional with respect to reactivity
with aldehyde, where the fatty acid contributes at least 15% of the
weight of the listed reactants, and the resin has a softening point
of at least 120.degree. C.
[0106] For each of aspects (i) through (vii) identified above, the
process may optionally be further characterized in terms of one or
more of the features disclosed herein. For example, the reactants
may further comprise polyol. As another example, the reactants may
further comprise .alpha.,.beta.-olefinically unsaturated carbonyl
compound. As another example, the reactants further comprise metal
oxide. Of course, the reactants may include two or more of polyol,
.alpha.,.beta.-olefinically unsaturated carbonyl compound, and
metal oxide. As a final example, some or all of the phenolic
compound that is at least trifunctional with respect to reactivity
with aldehyde may be phenol.
[0107] According to the present invention, a combination of resin
acids and fatty acids may be used in the preparation of a resin,
while still achieving a commercially desirable softening point,
when the reactants include aldehyde and phenolic compound that is
at least trifunctional with respect to reactivity with aldehyde.
The phenolic compound that is at least trifunctional with respect
to reactivity with aldehyde is a highly reactive material, more
reactive than, e.g., phenolic compound that is difunctional with
respect to reactivity with aldehyde such as nonylphenol. When
phenolic compound that is at least trifunctional with respect to
reactivity with aldehyde is used as sole phenolic material used in
the preparation of the resin, and the fatty acid provides about
5-40% of the total weight of the reactants, then the phenolic
compound preferably provides about 5-15%, more preferably about
7-12% of the total weight of the reactants, with a preferred
formaldehyde/phenolic compound ratio of about 2-4. At high phenolic
compound levels, the reactants tend to form a gel, which is
undesirable. At lower phenolic compound levels, the softening point
of the resin is often less than 100.degree. C., which is
undesirable for many, although not all, commercial
applications.
[0108] In general, the use of more fatty acid is preferably
accompanied by the use of more phenolic compound that is at least
trifunctional with respect to aldehyde reactivity. For example, if
the fatty acid contributes about 35% of the total weight of the
reactants, a reaction mixture with 7% phenolic compound will tend
to provide a resin with a lower softening point than is obtained if
the reaction mixture includes 11% phenolic compound. It is possible
to increase the total amount of phenolic compound present in the
reaction mixture by using a combination of phenolic compound that
is difunctional with respect to aldehyde reactivity, and phenolic
compound that is at least tri-functional with respect to aldehyde
reactivity.
[0109] In general, gels are less likely to form if the fatty acid
provides less than about 35% of the total weight of the reactants,
the phenolic compound that is at least trifunctional with respect
to aldehyde reactivity provides less than about 12% of the total
weight of the reactants, and the weight ratio of aldehyde to
phenolic compound is less than about 3.5. When the aldehyde to
phenolic compound ratio is reduced, some maleic anhydride may be
included among the reactants in order to maintain or increase the
softening point of the resin. Polyol, e.g., pentaerythritol, may
also be included among the reactants in order to increase the
softening point of the resin.
[0110] 3. Phenolic Compound
[0111] Phenolic compounds are reactive with formaldehyde and other
aldehydes at the (two) ortho and (one) para positions of the
aromatic ring, relative to the location of the hydroxyl group that
is also directly bonded to the aromatic ring. Resins of the present
invention may be prepared from phenolic compound(s) that are at
least trifunctional. That is, at least some of the phenolic
compound utilized in preparing the inventive resin may have at
least three hydrogen atoms located ortho or para to a hydroxyl
group that is also directly bonded to an aromatic ring.
[0112] Tri- or higher-functional phenols are a preferred reactant
in the resin-forming compositions of the present invention. The
trifunctional phenols suitable for use in the compositions of this
invention include phenol itself (monohydroxybenzene, CAS #
108-95-2) and the meta substituted derivatives of phenol such as
m-cresol, resorcinol, m-chlorophenol, 3,5-dimethylphenol, and the
like. The tetrafunctional phenols suitable for use in the
compositions of this invention include 2,2-bis(4-hydroxyphenyl)
propane, 2,2-bis(4-hydroxyphenyl)ethane,
4,4'-dihydroxydiphenylsulphide, 4,4'-dihydroxydiphenylsulphone,
4,4'-dihydroxybiphenyl, and the like.
[0113] In one embodiment, tri- or higher-functional phenols are the
only phenolic compound(s) used to prepare a resin of the invention.
In another embodiment, tri- or higher-functional phenols
constitutes at least 98% by weight of the total weight of phenolic
compound used to prepare a resin of the present invention. In other
embodiments of the invention, tri- or higher-functional phenols
constitutes at least 0.5 wt %, or (in additional embodiments) at
least 10 wt %, or at least 15 wt %, or at least 20 wt %, or at
least 25 wt %, or at least 30 wt %, or at least 35 wt %, or at
least 40 wt %, or at least 45 wt %, or at least 50 wt %, or at
least 55 wt %, or at least 60 wt %, or at least 65 wt %, or at
least 70 wt %, or at least 75 wt %, or at least 80 wt %, or at
least 85 wt %, or at least 90 wt %, or at least 95 wt % of the
total weight of the mixture of phenolic compounds used to form the
resin.
[0114] The at least trifunctional phenolic compound may be in
admixture with mono- and/or difunctional phenol compound, i.e.,
phenol compounds having only one (for monofunctional) or only two
(for difunctional) hydrogen substitutions at the ortho and para
positions relative to the phenolic hydroxyl group. Exemplary mono-
and difunctional phenolic compounds have one or two non-hydrogen
substituents at the ortho and para positions, where exemplary
substituents include alkyl groups, e.g., C1-C12 alkyl groups,
cycloaliphatic groups, e.g., C6 cycloaliphatic groups, and aryl
groups, e.g., phenyl.
[0115] Although alkylphenols pose potential health concerns, they
are commonly used in the preparation of rosin-phenolic resins
because the alkyl chain imparts needed aliphatic solvent
compatibility to the resin. That is, in order for the resin to be
commercially viable, it should be soluble in the types of solvents
that are utilized for the target ink, typically either lithographic
or gravure ink. In these types of ink, the resins must be soluble
in aliphatic solvent. In order to achieve this aliphatic solvent
solubility, ink resins that utilize rosin and phenolic compounds
typically turn to alkyl phenols because the presence of the alkyl
group is thought to provide or enhance the needed aliphatic solvent
solubility.
[0116] In a very surprising discovery, the present inventor has
found that it is not necessary to include alkyl phenol in a
resin-forming reaction, in order for the product resin to have the
necessary aliphatic solvent solubility. Instead, phenol itself or
another tri- or higher-functional phenolic compound may be used in
lieu of some, or even all, of the alkyl phenol commonly used in
resin-forming reactions, so long as the resin-forming reactants
also include fatty acid.
[0117] In various aspects of the present invention, phenolic
compound is up to 50%, or up to 40%, or up to 30%, or up to 20%, or
1-15%, or 1-50%, or 1-40%, or 1-30%, or 1-20%, or 1-15%, or 2-50%,
or 2-40%, or 2-30%, or 2-20%, or 2-15%, or 3-50%, or 3-40%, or
3-30%, or 3-20%, or 3-15%, or 4-50%, or 4-40%, or 4-30%, or 4-20%,
or 4-15%, or 5-50%, or 5-40%, or 5-30%, or 5-20%, or 5-15% of the
total weight of the resin-forming reactants. In additional aspects
of the invention, for each of these percentage ranges, tri- or
higher-functional phenols may constitute 0-100%, or any of the
ranges set forth above, of the phenolic compound. In a preferred
embodiment, the phenolic component contributes about 5-15 wt % of
the total weight of the reactants used to form the resin.
[0118] In various aspects of the invention, when tri- or
higher-functional phenols constitutes 100% of the phenolic compound
present in the reactant components, the fatty acid constitutes at
least 5 wt %, or at least 10 wt %, or at least 15 wt %, or at least
20 wt %, or at least 25 wt %, or at least 30 wt %, or at least 40
wt % of the total weight of the reactants used to form the
resin.
[0119] In other aspects, when tri- or higher-functional phenols
constitutes at least 85 wt % of the phenolic compound present among
the reactant components, the fatty acid constitutes at least 5 wt
%, or at least 10 wt %, or at least 15 wt %, or at least 20 wt %,
or at least 25 wt %, or at least 30 wt %, or at least 40 wt % of
the total weight of the reactants used to form the resin.
[0120] In other aspects, when tri- or higher-functional phenols
constitutes at least 80 wt % of the phenolic compound present among
the reactant components, the fatty acid constitutes at least 5 wt
%, or at least 10 wt %, or at least 15 wt %, or at least 20 wt %,
or at least 25 wt %, or at least 30 wt %, or at least 40 wt % of
the total weight of the reactants used to form the resin.
[0121] In other aspects, when tri- or higher-functional phenols
constitutes at least 60 wt % of the phenolic compound present among
the reactant components, the fatty acid constitutes at least 5 wt
%, or at least 10 wt %, or at least 15 wt %, or at least 20 wt %,
or at least 25 wt %, or at least 30 wt %, or at least 40 wt % of
the total weight of the reactants used to form the resin.
[0122] In other aspects, when tri- or higher-functional phenols
constitutes at least 55 wt % of the phenolic compound present among
the reactant components, the fatty acid constitutes at least 5 wt
%, or at least 10 wt %, or at least 15 wt %, or at least 20 wt %,
or at least 25 wt %, or at least 30 wt %, or at least 40 wt % of
the total weight of the reactants used to form the resin.
[0123] In other aspects, when tri- or higher-functional phenols
constitutes at least 35 wt % of the phenolic compound present among
the reactant components, the fatty acid constitutes at least 5 wt
%, or at least 10 wt %, or at least 15 wt %, or at least 20 wt %,
or at least 25 wt %, or at least 30 wt %, or at least 40 wt % of
the total weight of the reactants used to form the resin.
[0124] In other aspects, when tri- or higher-functional phenols
constitutes at least 25 wt % of the phenolic compound present among
the reactant components, the fatty acid constitutes at least 5 wt
%, or at least 10 wt %, or at least 15 wt %, or at least 20 wt %,
or at least 25 wt %, or at least 30 wt %, or at least 40 wt % of
the total weight of the reactants used to form the resin.
[0125] In other aspects, tri- and higher-functional phenols
constitute 5-15% of the total weight of the resin-forming reactants
when fatty acid constitutes 5-25% of the total weight of the
resin-forming reactants. In other aspects, tri- and
higher-functional phenols constitute 7.5-10% of the total weight of
the resin-forming reactants when fatty acid constitutes 5-25% of
the total weight of the resin-forming reactants. In other aspects,
tri- and higher-functional phenols constitute 5-15% of the total
weight of the resin-forming reactants when fatty acid constitutes
10-20% of the total weight of the resin-forming reactants. In other
aspects, tri- and higher-functional phenols constitute 7.5-12.5% of
the total weight of the resin-forming reactants when fatty acid
constitutes 10-20% of the total weight of the resin-forming
reactants.
[0126] In each of these many aspects, the invention optionally
provides that Monomer constitutes 100%, or 90%, or 80%, or 70%, or
60%, or 50%, or 40%, or 30%, or 20%, or 10% of the total weight of
the fatty acid.
[0127] 4. Aldehyde
[0128] The aldehyde of the present invention is reactive with resin
acid and phenol, to produce crosslinked resinous adducts. Exemplary
aldehydes of the present invention include, without limitation,
formaldehyde, paraformaldehyde, acetaldehyde, glyceraldehyde,
butyraldehyde, isobutyraldehyde, benzaldehyde, furfural, and
glyoxal.
[0129] In one aspect, the resins of the invention are prepared from
formaldehyde (chemical formula CH.sub.2O) or a reactive equivalent
thereof. Since formaldehyde is a gas at room temperature and
ambient pressure, it is somewhat difficult to work with in a
laboratory or commercial setting. Accordingly, use of a reactive
equivalent thereof, such as a formaldehyde-generating compound in
either liquid or solid form, is a preferred manner to introduce
formaldehyde into a chemical reaction. For example, formaldehyde
may be dissolved in water, where it forms "formalin," of chemical
formula HO(CH.sub.2O).sub.nH, where n is roughly 2. Formalins
having both 36 wt % and 50 wt % formaldehyde activity are
commercially available, and may be used in the practice of this
invention.
[0130] A preferred reactive equivalent of formaldehyde is
paraformaldehyde, which is a solid, water-free oligomer or polymer
of formaldehyde. Paraformaldehyde has the chemical formula
HO(CH.sub.2O).sub.nH wherein n is on the order of 20 to 100.
Paraformaldehyde is commercially available from many sources,
including Celanese (Dallas, Tex.). Bulk paraformaldehyde has an
aldehyde equivalent weight of roughly 91% of the weight of
paraformaldehyde. Other, less preferred sources of formaldehyde
include trioxane and hexamethylenetetramine. Trioxane and
hexamethylenetetramine are less preferred because their use
necessitates special equipment and handling conditions in order to
release formaldehyde activity from these chemicals.
[0131] In various aspects of the present invention, aldehyde is up
to 40%, or up to 30%, or up to 20%, or up to 5%, or 2-40%, or
2-30%, or 2-20%, or 2-15%, or 3-40%, or 3-30%, or 3-20%, or 3-15%,
or 4-40%, or 4-30%, or 4-20%, or 4-15%, of the total weight of the
reactants used to from the resin. Paraformaldehyde (CAS #
30525-89-4) is a preferred aldehyde to be used as a resin-forming
reactant, and it is preferably used at about 4-12 wt % of the
resin-forming components. The term "formaldehyde" is used herein
for convenience to include formaldehyde and reactive equivalents
thereof, e.g., paraformaldehyde and formalin.
[0132] 5. Phenolic Resin
[0133] In an optional aspect, the phenolic compound having at least
three aldehyde-reactive sites is pre-reacted with the aldehyde, so
as to provide a so-called phenolic resin. Thus, the present
invention provides that phenolic compound and aldehyde may be added
to the resin-forming reaction mixture in the form of a phenolic
resin, rather than, or in addition to, the two individual
reactants.
[0134] The phenolic resin useful in one aspect of the present
invention will necessarily be prepared, at least in part, from
phenolic compound having at least three reactive sites, i.e.,
phenolic compound having at least three hydrogens located at ortho
or para positions relative to a hydroxyl group directly bonded to
an aromatic ring. However, phenolic compound having at least three
reactive sites need not be the only phenolic compound used to
prepare the phenolic resin. When other phenolic compounds are
utilized to prepare the phenolic resin, then phenolic compound
having at least three reactive sites provides, in various aspects
of the invention, at least 10%, or at least 20%, or at least 30%,
or at least 40%, or at least 50%, or at least 60%, or at least 70%,
or at least 80%, or at least 90%, of the total weight of phenolic
compound used to form the phenolic resin.
[0135] In general, the phenolic resin may be prepared from
reactants in addition to phenolic compound and aldehyde. For
example, polymerizable monomers may be included among the
reactants, where styrene and divinyl benzene are exemplary
polymerizable monomers. In addition, ethers of phenolic compounds
may be used.
[0136] The phenolic resin may be of either the resole or novolak
form. These forms of phenolic resin are well known in the art. See,
e.g., Chemistry of Phenolic Resins, R. W. Martin, Chapter 5, Wiley
and Sons, New York, 1956. For example, phenolic compound (e.g.,
monofunctional phenolic compound, difunctional phenolic compound,
trifunctional phenolic compound, etc.) and aldehyde may be combined
in the presence of a reaction-promoting compound or catalyst. Known
reaction promoting compounds are of two types, (i) an alkali or
alkaline earth hydroxide or oxide such as sodium hydroxide,
potassium, hydroxide, calcium, hydroxide, barium hydroxide, calcium
oxide and the like; or (ii) an amine compound. Suitable amine
compounds include primary, secondary and tertiary amines having up
to about 10 carbon atoms such as ammonia, hydrazine, methylamine,
ethylamine, dimethylamine, trimethylamine, ethylenediamine,
hexamethylenetetramine, aniline, cyclohexylamine, benzylamine,
ethanolamine, and the like. When the amine type compound is
employed as the reaction-promoting compound it will become
incorporated into the product compositions. The reaction-promoting
compound is present in the reaction mixture at a concentration of
from 0.01 to 1 mole, preferably from 0.01 to 0.2 mole, per mole of
phenol moiety. When trifunctional or greater phenolic compound is
used in combination with a phenolic compound that is not
trifunctional or greater, then so-called mixed resoles and novolaks
may be prepared and utilized in the present invention.
[0137] B. Optional Reactants
[0138] One or more additional reactants may be included in the
reaction-forming mixture, where exemplary optional reactants are
discussed below.
[0139] 1. Polyol
[0140] In an optional aspect, the reactants used to form a resin of
the present invention further comprise polyol. Polyols of the
present invention are reactive with acidic moieties via standard
esterification reactions, and are reactive with ester moieties via
standard transesterification reactions, to produce crosslinked
resinous adducts. Exemplary polyols include, without limitation,
alkylene glycol (such as ethylene glycol and propylene glycol),
polyalkylene glycol (such as polyethylene glycol and polypropylene
glycol), alkylene triol (such as glycerol, trimethylolethane, and
trimethylolpropane), tetrafunctional alcohols such as
pentaerythritol, pentafunctional alcohols such as dimerized
trimethylolpropane, or hexafunctional alcohols such as dimerized
pentaerythritol, where a preferred polyol of the present invention
is pentaerythritol.
[0141] When polyol is desirably included as a component in a
resin-forming reaction, one option is to provide the polyol via a
polyester of the polyol and fatty acid. The polyester, upon
transesterification with other reactants, provides not only some or
all of the polyol, but also provides some or all of the fatty acid.
Accordingly, the polyol may be introduced to the reaction mixture
via an ester of the polyol. Likewise, the fatty acid may be
introduced to the reaction mixture via an ester of the fatty acid.
In one embodiment of the invention, polyester is utilized as a
reaction component to provide both polyol and fatty acid. In this
embodiment of the invention, the polyester is preferably but not
limited to a triglyceride, e.g., a vegetable oil.
[0142] In addition, the rosin may be esterified prior to being
utilized in the resin-forming reaction. If the ester is made from a
volatile alcohol, e.g., methanol, then the volatile alcohol will,
to a large extent, vaporize under the reaction conditions and be
removed from the reaction. However, when the alcohol is a high
boiling polyol, e.g., glycerin or pentaerythritol, then the polyol
will become a component of the product resin.
[0143] In various optional aspects of the present invention, polyol
(optionally incorporated into a polyester form) is up to 25%, or up
to 20%, or up to 15%, or up to 10%, or 1-25%, or 1-20%, or 1-15%,
or 1-10%, or 2-25%, or 2-20%, or 2-15%, or 2-10%, or 3-25%, or
3-20%, or 3-15%, or 3-10%, or 4-25%, or 4-20%, or 4-15%, or 4-10%
of the total weight of the reactants used to form the resin.
[0144] 2. .alpha.,.beta.-Olefinically Unsaturated Carbonyl
Compound
[0145] In another optional aspect, the reactants used to form a
resin of the present invention further comprise
.alpha.,.beta.-olefinically unsaturated carbonyl compound. The
.alpha.,.beta.-olefinically unsaturated carbonyl compound of the
present invention has an olefinic unsaturation adjacent to the
carbon atom of a carbonyl group, i.e., has the
--C.dbd.C--C(.dbd.O)-- arrangement of carbon and oxygen atoms. The
.alpha.,.beta.-olefinically unsaturated carbonyl compound may be
reacted with resin acids, rosin and/or fatty acid to form adducts.
When the .alpha.,.beta.-olefinically unsaturated carbonyl compound
is maleic anhydride, the adduct between rosin and maleic acid is
known as maleated rosin. When the .alpha.,.beta.-olefinically
unsaturated carbonyl compound is fumaric acid, or an ester of
fumaric acid, then the corresponding adduct formed between rosin
and fumaric acid or a fumarate is known as fumarated rosin.
[0146] Suitable .alpha.,.beta.-olefinically unsaturated carbonyl
compounds include maleic anhydride, fumaric acid, mono
(C.sub.1-C.sub.12alkyl) ester of fumaric acid,
di(C.sub.1-C.sub.12alkyl) ester of fumaric acid, acrylic acid,
C.sub.1-C.sub.12alkyl ester of acrylic acid, methacrylic acid,
C.sub.1-C.sub.12alkyl ester of methacrylic acid, itaconic acid, and
C.sub.1-C.sub.12alkyl ester of itaconic acid. Maleic anhydride,
fumaric acid and esters of fumaric acid are preferred
.alpha.,.beta.-olefinically unsaturated carbonyl compounds, with
maleic anhydride being most preferred.
[0147] Typically, when .alpha.,.beta.-olefinically unsaturated
carbonyl compound is included among the resin-forming reactants,
then polyol will also be present among the reactants. However, the
converse is not necessarily true, that is, polyol is often included
among the resin-forming reactants even though
.alpha.,.beta.-olefinically unsaturated carbonyl compound is not
included among the reactants. Accordingly, in one aspect of the
invention, both .alpha.,.beta.-olefinic- ally unsaturated carbonyl
compound and polyol are included among the resin-forming reactants,
where in a preferred embodiment the polyol includes
pentaerythritol. However, in another aspect, polyol is included
among the reactants but .alpha.,.beta.-olefinically unsaturated
carbonyl compound is not included among the reactants.
[0148] In various optional aspects of the present invention,
.alpha.,.beta.-olefinically unsaturated carbonyl compound is up to
15%, or up to 10%, or up to 8%, or up to 5%, or 0.1-15%, or
0.1-10%, or 0.1-8%, or 0.1-5%, or 0.5-15%, or 0.5-10%, or 0.5-8%,
or 0.5-5%, or 1-15%, or 1-10%, or 1-8%, or 1-5% of the total weight
of the resin-forming reactants. When it is present, the
.alpha.,.beta.-olefinica- lly unsaturated carbonyl compound is
preferably maleic anhydride, and it is preferably utilized at a
concentration of about 2-4 wt % of the total weight of the
resin-forming reactants. The presence of maleic anhydride or other
.alpha.,.beta.-olefinically unsaturated carbonyl compound among the
resin-forming reactants tends to increase the softening point of
the product resin.
[0149] 3. Alkaline Metal Salt
[0150] An alkaline metal salt is preferably included among the
resin-forming reactants as a catalyst for the phenol-aldehyde
polymerization. When it functions only as a catalyst, the metal
salt is preferably present at a concentration of less than 5 wt %
based on the total weight of the reactants. However, the metal salt
may also, or alternatively, react with the rosin so as to form
resinate, where the term "resinate" refers to a rosin (which is a
carboxylic acid-containing material) in the form of a salt, i.e., a
carboxylic acid salt. Thus, in one aspect of the resin composition
of the present invention, alkaline metal salt is combined with
rosin, which reacts with the carboxylic acid moiety present in the
resin acid components of rosin to produce metal carboxylate
functionalities. Such treatment renders the resulting resinate
composition readily soluble in organic solvent, and also increases
the melting point of the rosin. Thus, the metal salt may also
become an important component of the resin-forming mixture.
[0151] In the present invention, the alkaline metal salt preferably
has a cation selected from Group IIA or Group IIB of the Periodic
Table. The alkaline metal salt is preferably divalent, i.e.,
carries a charge of +2. Rosin salts of divalent cations of zinc,
magnesium, and calcium have particularly good pigment wetting
properties, and are preferred in the resinates of the present
invention. More preferably, the cation of the alkaline metal salt
is divalent magnesium cation. Said salts may be, e.g., the acetate,
carbonate, bicarbonate, formate, hydroxide, oxalate or oxide of a
metal. Magnesium salts (including without limitation, magnesium
oxide and magnesium hydroxide) are further preferred.
[0152] In various aspects of the present invention, alkaline metal
salt is up to about 10%, or 8%, or 5%, or 4%, or 3%, or 2%, or 1%,
or 0.5% of the total weight of the resin composition. A preferred
metal salt for catalytic purposes is magnesium oxide, which may be
used at a concentration of less than 1 wt %. A preferred salt for
resin-forming purposes is calcium oxide, which may be used at a
concentration of about 4 wt %. The metal salt is preferably
introduced into the reaction mixture in the form of a slurry, that
is, a mixture of metal salt and solvent, preferably a hydrocarbon
solvent (e.g., xylene) optionally with fatty acid present.
[0153] 4. Hydrocarbon-Containing Resins
[0154] Resins prepared in whole or part from a hydrocarbon monomer
may optionally be included among the reactants and/or may be
admixed with a resin of the present invention. The term
"hydrocarbon monomer" refers to a monomer formed entirely from
carbon and hydrogen. Exemplary hydrocarbon monomers are provided
below, and include cyclopentadiene, dicyclopentadiene, styrene, and
alpha-olefin. The following provides some discussion of these
monomers and the resins prepared therefrom.
[0155] a. C5 Resins
[0156] Aliphatic C5 hydrocarbon resins can be prepared by cationic
polymerization of a cracked petroleum feed containing C5 and C6
paraffins, olefins, and diolefins, collectively referred to as "C5
monomers". 1,3-Pentadiene is a commonly used component for making
C5 resins, where 1,3-pentadiene may be in admixture with one or
more similarly reactive hydrocarbons such as cyclopentene, pentene,
2-methyl-2-butene, 2-methyl-2-pentene, cyclopentadiene, and
dicyclopentadiene. The polymerizations are catalyzed using
Friedel-Crafts polymerization catalysts such as Lewis acids, e.g.,
boron trifluoride or complexes thereof (e.g., etherates), aluminum
trichloride, or alkyl aluminum chlorides.
[0157] b. DCPD Resins
[0158] Hydrocarbon-containing resins may be prepared by the
polymerization of cyclopentadiene or dicyclopentadiene (DCPD). The
DCPD resin may be prepared from monomers in addition to
cyclopentadiene and/or dicyclopentadiene, e.g., hydrocarbon
monomers such as ethylene, propylene, styrene, .alpha.-methyl
styrene, indene, 1,3-pentadiene, isobutylene, isoprene, 1-butene,
2-methyl-2-butene, 1-pentene, 1-hexene, 1-octene, piperylene,
isoprene, limonene, .alpha.-pinene, .beta.-pinene, butadiene and
vinyl toluene. The cyclopentadiene and/or dicyclopentadiene may
optionally be reacted with olefinic monomers that contain oxygen,
e.g., methacrylic acid, acrylic acid, and esters thereof. Methods
to prepare DCPD resins are well known in the art, see, e.g., U.S.
Pat. Nos. 5,693,731; 5,691,432; 5,587,007; and 5,410,004.
[0159] c. C9 Resins
[0160] Aromatic C9 hydrocarbon resins can be prepared by cationic
polymerization of aromatic C8, C9, and/or C10 unsaturated monomers
derived from petroleum distillates resulting from naphtha cracking
and are referred to as "C9 monomers". Exemplary C9 monomers include
styrene, .alpha.-methyl styrene, .beta.-methyl styrene, vinyl
toluene, indene, dicyclopentadiene, divinylbenzene, and other alkyl
substituted derivatives of these compounds. The polymerizations are
catalyzed using Friedel-Crafts polymerization catalysts. The resins
may be hydrogenated to provide hydrogenated C9 resins. These C9
resins may be included as a component in the reaction mixture to
prepare a resin of the present invention, and/or these C9 resins
may be admixed with a resin of the present invention in the
preparation of a varnish or ink. C9 resins are commercially
available from many vendors, and the preparation of C9 resins is
well known in the art.
[0161] d. Styrenic Resins
[0162] Hydrocarbon resins can be prepared by cationic
polymerization of styrene-based monomers such as styrene,
.alpha.-methyl styrene, vinyl toluene, and other alkyl substituted
styrenes using Friedel-Crafts polymerization catalysts such as
Lewis acids. These styrenic resins may be included as a component
in the reaction mixture to prepare a resin of the present
invention, and/or these styrenic resins may be admixed with a resin
of the present invention in the preparation of a varnish or ink.
Styrene resins are commercially available from many vendors and
their preparation is well known.
[0163] e. Terpene Resins
[0164] Terpene resin may function as a hydrocarbon resin, and be
included within the reaction mixture used to form the resin of the
present invention, or be admixed with the resin of the present
invention. Generally, terpene resins are somewhat expensive, and
for this reason they are not a preferred component. Alpha-pinene,
beta-pinene, dipentene and limonene are four terpenes commonly used
to prepare terpene resins. In the preparation of a terpene resin,
some co-reactive non-terpenic monomer may be included, e.g.,
styrene, p-t-butyl styrene or vinyl toluene. Terpene resins of this
type are well known and commercially available.
[0165] In general, hydrocarbon monomer-containing resins can be
either included as a component of the reactants used to prepare an
ink resin of the present invention, or they can be admixed with an
ink resin of the present invention. In either event, in optional
aspects of the invention, the hydrocarbon monomer-containing resin
will constitute 5%, or 10%, or 15%, or 20%, or 25%, or 30%, or 35%,
or 40%, or 45%, or 50%, or 55%, or 60%, or 65%, or 70%, or 75%, or
80%, or 85%, or 90%, or 95% of the total weight of the ink
resin.
[0166] 5. Solvent
[0167] One or more inert solvents may be included with, i.e., be in
admixture with, the reactants used to form a resin of the
invention. However, solvent is not construed to be a "component" of
the reaction mixture, since it does not participate in the
resin-forming reaction. Nevertheless, it may be convenient to
include one or more solvents in the reaction vessel, where
hydrocarbons, e.g., xylenes, are an exemplary solvent.
[0168] C. Sources of Resin Acid and Fatty Acid
[0169] Resin acids are commercially available from many suppliers.
In essentially all cases, suppliers of resin acid obtain the resin
acid from trees, most commonly pine trees. There are many different
processes for obtaining resin acid from trees, where these
different processes provide not only various mixtures of resin
acids, but also various mixtures of resin acids in combination with
various other materials found in pine trees, particularly fatty
acid, terpenes, lignin and pitch.
[0170] For instance, a suitable source of resin acid for the
present invention is one of the by-products produced by the Kraft
papermaking process. Briefly, according to this well-known process,
pine chips are fed into a digester along with an alkaline cooking
liquid, and the mixture is maintained at elevated temperature. The
resulting product includes the salts of resin acids and fatty
acids, which are skimmed from the top of the digester, where the
skimming is known as tall oil soap. Upon acidification, tall oil
soap yields crude tall oil (CTO).
[0171] CTO contains fatty acids and resin acids, in roughly equal
amounts, along with some other reactants. While the fatty acids and
resin acids are both monocarboxylic acids having 18-20 carbon
atoms, these materials have different chemical structures, and thus
the physical and chemical properties of fatty acids and resin acids
are quite different. In order to take advantage of these different
properties, distillation processes are commonly performed on CTO,
to thereby obtain purified resin acids (commonly called rosin) and
purified fatty acids (commonly called tall oil fatty acids, or
TOFA). In addition to rosin and fatty acids, CTO distillation
yields one or more head cuts, a pitch residue, and a material
called distilled tall oil (DTO). These materials are obtained by
the following, more precisely described process.
[0172] The CTO is heated to distill all volatile materials, which
include the components of heads, rosin, TOFA, and some material
that ultimately ends up as DTO, yielding residue that is known as
pitch. The distillate is then re-heated to distill a volatile
fraction including the components of heads, TOFA, and further
material that ultimately ends up as DTO, yielding residue called
rosin, or tall oil rosin (TOR). The distillate from this process is
then heated once again, to distill a heads fraction and a fatty
acids fraction (TOFA), yielding residue known as distilled tall oil
(DTO).
[0173] Any of these mixtures may be the source of the resin acid
and/or fatty acid of the present invention. In a preferred
embodiment, the resin acid comes from rosin. In another preferred
embodiment, the fatty acid comes from TOFA.
[0174] As mentioned above, DTO may be used in the practice of the
present invention. While the exact composition of DTO is not
completely known, it is clear that DTO is not the same as crude
tall oil, pitch, rosin or tall oil fatty acid, nor is it simply a
blend of these materials. In fact, although DTO is distilled from
CTO, the extensive heating employed during the distillations
described above provides that DTO contains materials that are not
even present in CTO. A general characterization of DTO is made
difficult because it depends on the composition of the precursor
CTO, which itself will vary depending on the identity of the trees
from which the CTO was obtained and even the time of year that the
trees were cut. Furthermore, there is also variability among CTO
fractionators as far as the temperatures and pressures that are
used during each distillation step and the duration of each step.
These are important parameters because DTO is, to a large extent,
the result of thermal isomerization, degradation and polymerization
processes, and the degree to which each of these processes will
occur is dependent on the fractionation conditions.
[0175] Roughly, DTO contains 20-45 weight percent of a fatty
acid-like component, 15-35 weight percent of a rosin-like
component, and 10-35 weight percent of a "less-volatile" component
that has not been clearly traced to either resin or fatty acids.
While rosin contains predominately abietane resin acids, DTO
typically contains a predominant amount of pimarane resin acids. In
a typical DTO, resin acids of the pimaranes and isopimaranes
constitute the majority of the resin acids present in the DTO. Also
typically, resin acids of the abietane family constitute less than
10 weight percent of the DTO. Indeed, the total weight of the
abietic acid, neoabietic acid and palustric acid is typically less
than 10 weight percent of the total weight of the DTO, and more
typically is less than 5 weight percent of the total weight of the
DTO. Typically, resin acids of the pimarane and isopimarane
families constitute at least 50 wt %, and more typically at least
about 60 wt % of the resin acids present in the DTO. DTO may
provide some or all of the resin acids or fatty acids in preparing
a resin of the present invention.
[0176] As mentioned above, rosin is a preferred source for resin
acids. In general, rosin is a well-known, commercially available
material. In terms of its chemical structure, it is mainly a
mixture of C.sub.20, tricyclic fused-ring, mono-carboxylic acids,
i.e., resin acids. Rosin can be obtained from many sources, and can
have a wide range of purities. For example, wood rosin is obtained
from Pinus stumps after harvesting the stumps, chipping the stumps
into small chips, extracting the chips with hexane or
higher-boiling paraffins, and distilling the hexane or paraffin and
fatty acids to yield wood rosin. Gum rosin is the name given to
rosin that is obtained after scoring a pine tree, collecting the
exudate sap, and then distilling away the volatile components and
most of the fatty acids. As discussed above, the Kraft wood pulping
process, also known as the sulfate pulping process, produces tall
oil rosin (TOR).
[0177] For clarity, it will be noted that as the term is used
herein, "rosin" refers to rosin from any source, including tall oil
rosin (by-product from wood pulping process), gum rosin (obtained
by scoring trees and collecting/refining the exudate) and wood
rosin (obtained from pine stumps by extractive and/or distillative
methods). The term "rosin" also includes treated rosin, where
treated rosin refers to rosin that has been subjected to
disproportionation and/or hydrogenation conditions. The term
"rosin" also includes dimerized rosin. The term "rosin" also
includes compositions that include resin acids in mixture with
non-resin acids, e.g., Indonesian gum rosin contains resin acids
but also contains about 8-10% of a polycyclic dicarboxylic acid.
Indonesian gum rosin is a rosin, and a source of resin acid, for
the present invention.
[0178] Each of disproportionated, hydrogenated and dimerized rosin,
as well as other rosin/resin acid derivatives and reaction
products, are well known in the art and many have been described
previously herein. The term "natural rosin" will be used herein to
refer to untreated rosin, that is, rosin that is known commercially
as "rosin", and has, for example, CAS # 8052-10-9 (Tall Oil Rosin)
or CAS # 8050-09-7(Gum Rosin). In a preferred aspect of the present
invention, natural rosin provides the source of all or most of the
resin acids used in the inventive process and resins.
[0179] Rosin is typically characterized by its acid number, and
rosins having acid numbers ranging from about 160 to about 180 are
preferred, but not necessarily utilized, in the practice of the
present invention. Typically, the acid content of rosin is due to
the presence of resin acids and fatty acids. Although rosin
manufacturers typically seek to provide rosin having little or no
fatty acid, in practice it is quite expensive to remove all of the
fatty acid from rosin. Accordingly, the rosin used in the present
invention may contain some fatty acid. However, fatty acid is
typically a minor component of rosin, and typically the rosin
contains less than 10 wt %, and more typically less than 5 wt %
fatty acid. In one aspect, the rosin used in the present invention
is tall oil rosin that has undergone distillation so as to have
less than about 5 weight percent tall oil fatty acids. A preferred
rosin is available commercially from Arizona Chemical Company,
Jacksonville, Fla., under the SYLVAROS.RTM. trademark. Because
rosin contains little or no fatty acid, rosin alone typically
cannot provide sufficient fatty acid for the practice of the
present invention.
[0180] Optionally, the rosin can be characterized in terms that
describe the source of at least 90% of the total weight of the
rosin. For example, in one aspect of the invention, tall oil rosin
provides at least 90% of the weight of the rosin used to prepare a
resin of the invention. In one aspect, a mixture of gum rosin and
tall oil rosin is used to form the resin of the invention.
[0181] Fatty acid may be obtained from either natural sources or by
synthetic means. Fatty acids may be obtained from plants (e.g.,
corn, safflower, and other vegetable oil) and animals (e.g., fish
oil, lard). Fatty acid may also be obtained via the oxidation of
petroleum-derived materials, e.g., the oxidation of short
polyethylene molecules. Genetically-modified plants and animals,
which may be considered either natural sources or synthetic
sources, may also yield fatty acids. Either synthetic or natural
fatty acid may be used as a reactant component in the present
invention. In one aspect of the invention, the fatty acid is
vegetable-derived, i.e., comes from vegetable oil. In another
aspect, the fatty acid is tree-derived, e.g., tall oil fatty acid
(TOFA). A preferred fatty acid has been assigned CAS #
68955-98-6.
[0182] In one aspect of the present invention, the fatty acid
component is, or includes, Monomer. While Monomer is well known in
the art, for additional clarity the production of a preferred
Monomer of the invention will be briefly summarized, starting with
the wood pulping process. The digestion of wood to make pulp leads
to the formation of black liquor. Black liquor is composed of,
among other things, rosin soap and fatty acid soap. Acidification
of these soaps followed by fractionation yields rosin and fatty
acid as two of the components. The rosin obtained by this process
is known as tall oil rosin (TOR) and the fatty acid obtained by
this process is known as tall oil fatty acid (TOFA). TOFA is
composed mainly of C.sub.16-18 carboxylic acids, which are largely
unsaturated in their hydrocarbon chain structure. Exemplary tall
oil fatty acids include unsaturated acids such as oleic acid, oleic
acid isomers, linoleic acid, and linoleic acid isomers, as well as
small percentages of saturated fatty acids such as stearic
acid.
[0183] Due to its high content of unsaturated fatty acid, TOFA may
be, and commonly is, subjected to acidic clay catalyzed
polymerization. In this polymerization process, which is typically
conducted at high temperatures, the olefinic fatty acids undergo
intermolecular addition reactions, by, e.g., the ene-reaction, so
as to form polymerized fatty acid. The mechanism of this reaction
is complex and incompletely understood at the present time.
However, for purposes of the present invention it will suffice to
note that the product of this polymerization process comprises, in
large part, dimerized fatty acid and a unique mixture of monomeric
fatty acids. This polymerization product is commonly (in commercial
settings) subjected to distillation in order to provide a fraction
highly enriched in dimerized fatty acid, which is commonly known in
the art as "dimer acid" or "dimer fatty acid". This distillation
process will also provide a fraction that is highly enriched in the
monomeric fatty acids, where this fraction is commonly known in the
art as "monomer" or "monomer acid" or "monomer fatty acid," and
will be referred to herein as Monomer (with a capital M).
[0184] Monomer is a unique composition. Whereas the natural
source-derived TOFA largely consists of linear C.sub.18 unsaturated
carboxylic acids, principally oleic and linoleic acids, Monomer
contains relatively small amounts of oleic and linoleic acids, and
instead contains significant amounts of branched and cyclic C18
acids, both saturated and unsaturated, as well as elaidic acid. For
example, a typical commercially-available Monomer contains ca. 30%
C18 branched chain fatty acid (including saturated and unsaturated
fatty acids) and 10% C18 cyclic chain fatty acid. The more diverse
and significantly branched composition of Monomer results from the
thermal catalytic processing carried out on TOFA by the
polymerization process just described.
[0185] While a preferred Monomer used in the present invention is
derived from TOFA, unsaturated fatty acids from any other source
may likewise be subjected to a polymerization process that yields
dimer fatty acid and a residual mixture of monomeric fatty acid
known as Monomer. For instance, unsaturated fatty acids from
vegetable oils may be subjected to a dimerization process, from
which dimer acid and Monomer may be obtained. Likewise, unsaturated
fatty acids may be produced by microorganisms, e.g., bacteria, and
from animal products/byproducts (e.g., fish oils).
[0186] Monomer has been assigned CAS Registry Number 68955-98-6. A
suitable Monomer for the practice of the present invention is
CENTURY.RTM. MO-6 specialty fatty acid, as available from Arizona
Chemical Company (Jacksonville, Fla.). This product is a
light-colored semi-solid, having an acid number of 180, a
saponification number of 187, an iodine number of 75, and a
viscosity of 35 centistokes at 40.degree. C. In a preferred aspect
of the present invention, the fatty acid of the resin-forming
composition is Monomer.
[0187] The art recognizes that the reaction of Monomer with other
chemical substances yields unique, identifiable derivative
substances that are chemically different from corresponding TOFA
derivatives. In fact, it has been surprisingly found that resins of
the present invention comprising Monomer exhibit properties of ink
binder performance superior to those demonstrated by resins
comprising TOFA.
[0188] Optionally, all of the fatty acid utilized in the process is
Monomer, in other words, 100% of the fatty acid is. Monomer.
However, in other aspects of the invention, less than all of the
fatty acid is provided by Monomer. For instance, in one aspect, 95%
of the fatty acid is Monomer. The following are various optional
means for characterizing the fatty acid according to the present
invention: 100% of the fatty acid is Monomer; at least 95% of the
fatty acid is Monomer; at least 90% of the fatty acid is Monomer;
at least 85% of the fatty acid is Monomer; at least 80% of the
fatty acid is Monomer; at least 75% of the fatty acid is Monomer;
at least 70% of the fatty acid is Monomer; at least 65% of the
fatty acid is Monomer; at least 60% of the fatty acid is Monomer;
at least 55% of the fatty acid is Monomer; at least 50% of the
fatty acid is Monomer; at least 45% of the fatty acid is Monomer;
at least 40% of the fatty acid is Monomer; at least 35% of the
fatty acid is Monomer; at least 30% of the fatty acid is Monomer;
at least 25% of the fatty acid is Monomer; at least 20% of the
fatty acid is Monomer; at least 15% of the fatty acid is Monomer;
at least 10% of the fatty acid is Monomer. The percent values are
weight percentages based on the total weight of fatty acid.
[0189] In a very surprising discovery, the present inventor has
found that enhanced aliphatic solubility can be obtained by using
branched-chain fatty acids and/or cyclic-chain fatty acids (in lieu
of the standard linear-chain fatty acids that are found in TOFA) in
the preparation of a rosin-phenolic resin. Thus, in a preferred
embodiment, Monomer is used as a resin-forming component.
Optionally, the fatty acid is a mixture of Monomer and TOFA. In
another optional embodiment, the fatty acid is entirely TOFA. In
another optional embodiment, the fatty acid is, in part TOFA, and
is, in part, a non-TOFA fatty acid, e.g., a vegetable oil-derived
fatty acid.
[0190] D. Process of Manufacture
[0191] The present invention provides a resin produced by a process
as described herein. The process includes reacting resin acid,
fatty acid, at least trifunctional phenolic compound, and aldehyde.
These reactants, and possibly optional reactants, are reacted
together at elevated temperature so as to form a resin. In order
for the reactants to undergo a resin-forming reaction, combinations
of the reactants must be exposed to an elevated temperature, for
example, one or more temperatures in the range of about
80-300.degree. C. At these elevated temperatures, the reactants
undergo covalent bond-forming reactions with other reactants, so
that high molecular weight products, i.e., a resin, forms.
[0192] There are different orders in which the reactants may be
charged to a reaction vessel. For example, each of the reactants
may be combined together in a single reaction vessel, and the
combination taken to elevated temperature so that the reactants
react with one another to form a resin of the invention. This
approach may be termed the "one-pot" reaction process.
Alternatively, two or more (but less than all) reactants may be
combined in a single reaction vessel, and this combination taken to
elevated temperature so that the reactants react with one another
to form an intermediate reaction product. Then other reactants are
reacted with the intermediate reaction product, where these "other
reactants" may be added individually to the reaction vessel, or two
or more of them may be pre-reacted with each other before the
pre-reacted reaction product is added to the reaction mixture.
[0193] For example, the resin acid (e.g., rosin) and fatty acid may
be combined and heated, during which process these two reactants
will form a fluid mixture. The resulting reaction mixture can then
be combined with the other reactants (e.g., phenolic compound
and/or aldehyde and/or .alpha.,.beta.-olefinically unsaturated
carbonyl compound and/or polyol, as well as other optional
reactants such as alkaline metal salt), and the complete admixture
formed either instantaneously, or in stepwise fashion, to allow
intermediate reactions to occur with minimal interference. The
resulting reaction mixture may alternatively be combined with a
reaction product of two or more of phenolic compound, aldehyde,
.alpha.,.beta.-olefinically unsaturated carbonyl compound and
polyol, in addition to further ingredients. To complete the
reaction process, the reaction mixture is taken to elevated
temperature, typically but not limited to, between about
150.degree. C. and about 300.degree. C., preferably 180.degree. C.
to 250.degree. C., under either normal (atmospheric) pressure or
reduced pressure as may be achieved, e.g., using a vacuum source.
The reduced pressure is conveniently employed to remove water and
other volatile materials from the reaction mixture.
[0194] As other exemplary orders of reaction, a molten mixture of
rosin and fatty acid is formed, and then maleic anhydride is added
at about 180.degree. C. and the mixture is maintained at this
temperature until essentially all of the maleic anhydride has been
consumed. Alternatively, rosin is heated with maleic anhydride to
about 180.degree. C. until all of the maleic has been consumed, and
then fatty acid is added. After either process, polyol is added and
then the mixture is cooled to about 110.degree. C., at which time
phenol and aldehyde, along with metal salt, is added. The
temperature is raised to about 225.degree. C. to complete the
formation of the resin.
[0195] Thus, the invention provides that the reactants may be
reacted with one another in any order, at temperatures within the
range of 80-300.degree. C., to obtain a resin of the invention. The
present invention also provides that after reacting together
reactants in a reaction mixture, an additional amount of one or
more of said reactants may be added to said reaction mixture and
further reacted together, a procedure commonly done in commercial
resin production. It should be recognized that the same reactants
(in terms of quantity and identity) may form resins with different
properties, depending on the precise manner in which the reactants
are reacted together. However, determining these properties is well
within the skill of the ordinary artisan.
[0196] Elevated reaction temperatures are selected in view of the
following points. The reaction temperature must be high enough that
the contents of the reaction vessel are sufficiently fluid to allow
those contents to be stirred. Higher temperatures are generally
preferred for reasons of economy, in order to provide a faster rate
of reaction When a solvent is used, a fluid state may be achieved
at a relatively lower temperature. The reaction temperature should
not be so great that the reactants boil out of the reaction vessel.
Nor should the temperature be so great that decomposition of the
reactants or reaction products should occur. The term "elevated" is
used to indicate that standard room temperature, i.e., ca.
23.degree. C., will not be hot enough to provide the fluid state
needed for the neat reactants. At a minimum, the elevated reaction
temperature should be about 80.degree. C., and is preferably at
least 100.degree. C. A lower temperature may be utilized if a
solvent is included within the reaction vessel.
[0197] The resin-forming reaction mixture may, and typically will
contain water; furthermore, the resin-forming reaction generates
water as a byproduct of the covalent bonds that are formed between
the reactants. In order to drive the reaction toward completion,
this water should be removed from the reaction or product mixture.
In the absence of vacuum or azeotrope formation, a reaction
temperature of at least 100.degree. C. is needed in order to
distill water away from the reactants. Thus, at least during the
initial stage(s) of resinate or ester formation, the reaction
temperature is desirably set to about 100-190.degree. C. While a
higher initial reaction temperature may be used, the consequence
may be water generation at a rate that is much greater than water
removal may be conveniently accomplished.
[0198] In order to drive the reaction to completion, removal of
water may be enhanced through addition of an organic solvent that
forms a low-boiling azeotrope with water, and/or the addition of a
vacuum on the reaction vessel. To provide a low-boiling azeotrope,
an organic solvent that forms an azeotrope with water, e.g., a
solvent such as but not limited to toluene or xylene, can be added
to the reaction vessel, and then removed by distillation, under
normal pressure. However, in one aspect of the invention,
azeotropic distillation is not used to remove water from the
resin.
[0199] The reactants are maintained at about 120-300.degree. C.
until the reaction is considered finished. Reaction progress is
conveniently monitored by periodically taking samples of the
reaction mixture and measuring one or more relevant properties of
the sample. For example, initially the acid number of the reaction
mixture may be as high as about 300. The acid number will gradually
fall as the resin-forming reaction proceeds. Melting point
(softening point), melt viscosity, solution viscosity and/or cloud
point measurements may also be made periodically to monitor
reaction progress.
[0200] The amounts of the various reactants are preferably selected
so that the reaction mixture does not form a gel during the heating
process. This is particularly important when the reaction mixture
contains multifunctional reactants, e.g., maleic anhydride and
pentaerythritol. However, gelling can also occur when only resin
acid, fatty acid, aldehyde and phenolic compound are used to form
the resin. A preferred property of a resin of the present invention
is that it is not a gel, and it is not in admixture with gel. In a
preferred aspect, a resin of the present invention may be dissolved
at elevated temperature in xylene at a 10 wt % concentration, and
upon cooling, a bright, clear solution results. This is indicative
of a resin that does not contain any gel.
[0201] The Examples contained herein provide several formulations
that do not gel. For example, a mixture of about 60 wt % gum rosin,
ca. 15 wt % phenol, ca. 15 wt % paraformaldehyde (91%), ca. 10 wt %
Monomer, and a trace (ca. 0.5 wt %) magnesium oxide can be used to
provide a fluid (when molten), rather than a gelled, resin. As
another example, a mixture of about 45 wt % gum rosin, ca. 20 wt %
tall oil rosin, ca. 8 wt % phenol, ca. 5 wt % paraformaldehyde
(91%), ca. 10 wt % Monomer, ca. 2 wt % maleic anhydride, ca. 10 wt
% pentaerythritol, and a trace (ca. 0.1 wt %) magnesium oxide can
be used to provide a fluid (when molten), rather than a gelled,
resin.
[0202] A preferred reaction mixture contains rosin, which
contributes 35-90 wt %, fatty acid, which contributes 10-30 wt %,
and aldehyde+phenolic compound that is at least trifunctional with
respect of aldehyde reactivity, either as individual monomers or as
pre-formed phenolic resin, which contributes 10-30 wt %, where the
phenolic compound is preferably phenol, each wt % value being based
on the total weight of the rosin, fatty acid, phenolic compound and
aldehyde present within the reactants.
[0203] Another preferred set of reactants is 35-70 wt % rosin, 5-40
wt % fatty acid, 5-25 wt % phenolic resin (or the total weight of
phenolic compound and aldehyde is within this range), and 5-15 wt %
polyol (preferably pentaerythritol), and some, but less than about
5 wt % .alpha.,.beta.-olefinically unsaturated carbonyl compound
(preferably maleic anhydride), based on the total weight of these
listed reactants, where in various embodiments of the invention at
least 50%, or at least 60%, or at least 70%, or at least 80%, or at
least 90%, or at least 95%, or all of the phenolic compound is
phenol or other phenolic compound that is at least trifunctional
with respect to aldehyde reactivity.
[0204] Another preferred set of reactants is 40-65 wt % rosin,
10-30 wt % fatty acid, 10-20 wt % phenolic resin (or the total
weight of phenolic compound and aldehyde is within this range), and
5-15 wt % polyol (preferably pentaerythritol), and some, but less
than about 5 wt % .alpha.,.beta.-olefinically unsaturated carbonyl
compound (preferably maleic anhydride), based on the total weight
of these listed reactants, where in various embodiments of the
invention at least 50%, or at least 60%, or at least 70%, or at
least 80%, or at least 90%, or at least 95%, or all of the phenolic
compound is phenol or other phenolic compound that is at least
trifunctional with respect to aldehyde reactivity.
[0205] Another preferred set of reactants is 45-60 wt % rosin,
10-30 wt % fatty acid, 10-20 wt % phenolic resin (or the total
weight of phenol and aldehyde is within this range), and 5-15 wt %
polyol (preferably pentaerythritol), and some, but less than about
5 wt % .alpha.,.beta.-olefinically unsaturated carbonyl compound
(preferably maleic anhydride), based on the total weight of these
listed reactants, where in various embodiments of the invention at
least 50%, or at least 60%, or at least 70%, or at least 80%, or at
least 90%, or at least 95%, or all of the phenolic compound is
phenol or other phenolic compound that is at least trifunctional
with respect to aldehyde reactivity.
[0206] Another preferred set of reactants is 30-65 wt % rosin, 5-35
wt % fatty acid, 5-25 wt % phenolic resin (or the total weight of
phenol and aldehyde is within this range), and 5-15 wt % polyol
(preferably pentaerythritol), based on the total weight of these
listed reactants, where in various embodiments of the invention at
least 50%, or at least 60%, or at least 70%, or at least 80%, or at
least 90%, or at least 95%, or all of the phenolic compound is
phenol or other phenolic compound that is at least trifunctional
with respect to aldehyde reactivity.
[0207] Within these ranges, exemplary specific formulations are
disclosed herein. In one preferred embodiment, the at least
trifunctional phenolic compound constitutes at least 25 wt % of the
total weight of the phenolic compounds, or other minimum values and
ranges as disclosed elsewhere herein.
[0208] If a reaction mixture does gel to an undesirable extent,
then an adjustment should be made in the amount of one or more of
the reactants. To this end, a statistical design of experiments may
be utilized to optimize a formulation for a particular end-use,
e.g., gravure vs. lithographic ink resin. Since the resins of the
invention preferably have a relatively high molecular weight, and
accordingly have a relatively high solution viscosity, successful
resin formulations are often close to those resin formulations that
yield an undesirable amount of gelled resin.
[0209] Thus, in one aspect, the present invention provides a resin
produced by a process, where the process includes reacting the
following reactants: resin acid, fatty acid, at least trifunctional
phenolic compound and aldehyde. In another aspect, the reactants
include .alpha.,.beta.-olefinically unsaturated carbonyl compound.
In another aspect, the reactants included polyol. In another
aspect, the reactants include both .alpha.,.beta.-olefinically
unsaturated carbonyl compound and polyol. The reactants are reacted
at elevated temperature so as to form a resin, preferably a
gel-free resin.
[0210] In another aspect, the present invention provides a resin
produced by a process, where the process includes reacting the
following reactants: resin acid, fatty acid, phenolic compound that
is at least trifunctional, aldehyde, and polyol. These reactants
are reacted at elevated temperature so as to form a resin. Another
exemplary product is formed by the process of reacting resin acid,
fatty acid and trifunctional phenolic compound at elevated
temperature, optionally with addition of a reaction catalyst,
followed by addition of paraformaldehyde, followed by the addition
of polyol. However, other orders of combination of the reactants
may also be employed to prepare a product of the present invention.
Also, as stated above, rosin may serve as the source of resin
acid.
[0211] In another aspect, the present invention provides a resin
produced by a process, where the process includes reacting the
following reactants: resin acid, fatty acid, phenolic compound that
is at least trifunctional, aldehyde, .alpha.,.beta.-olefinically
unsaturated carbonyl compound, and polyol. These reactants are
reacted at elevated temperature so as to form a resin. An exemplary
product is formed by the process of reacting resin acid, fatty acid
and at least trifunctional phenol at elevated temperature,
optionally with addition of a reaction catalyst, followed by
addition of paraformaldehyde, followed by the addition of
.alpha.,.beta.-olefinically unsaturated carbonyl compound, followed
by the addition of polyol. However, other orders of combination of
the reactants may also be employed to prepare a product of the
present invention, as described below.
[0212] In a preferred aspect, the process for preparing a resin of
the present invention comprises the ordered steps of:
[0213] a) heating rosin in a reaction vessel, optionally at about
140-180.degree. C., optionally in admixture with fatty acid and
phenolic compound that is at least trifunctional, until a
homogeneous molten liquid is formed;
[0214] b) further charging the reaction vessel with, if not
present, fatty acid and the phenolic compound that is at least
trifunctional, then allowing the reaction mixture to react,
optionally at about 100-140.degree. C., optionally for up to about
60 minutes;
[0215] c) further charging the reaction vessel with aldehyde and
metal catalyst, then allowing the reaction mixture to react,
optionally at about 100-180.degree. C., optionally for up to about
300 minutes;
[0216] d) further optionally charging the reaction vessel with
.alpha.,.beta.-olefinically unsaturated carbonyl compound, then
allowing the reaction mixture to react, optionally at about
120-250.degree. C., optionally for up to about 150 minutes;
[0217] e) further optionally charging the reaction vessel with
polyol, then allowing the reaction mixture to react, optionally at
about 120-310.degree. C., optionally for up to about 48 hours.
[0218] Overall, it typically takes at least about 4 hours to
prepare a resin from resin acid, fatty acid, phenolic compound
having a functionality of at least three, aldehyde and metal oxide
where a temperature of about 110.degree. C. is used when the
reactants are being combined, and a temperature of about
210.degree. C. is used when the reactants are being reacted
together to form the resin. Resin formation occurs when the
reactants react with one another so as to create higher molecular
weight materials, where longer reaction times typically provide for
a greater amount of high molecular weight material, and also
provide for resin of relatively higher molecular weight, i.e., the
average molecular weight of the product mixture (resin) generally
increases with increased reaction time. When polyol,
.alpha.,.beta.-olefinically unsaturated carbonyl compound, and/or
other optional reactants are utilized, then the reaction period
must typically be extended to allow time for these optional
components to react. With the exception of the metal oxide
catalyst, each of the reaction components participates in the
resin-forming reaction, i.e., each of the reactants contributes
carbon atoms to the final high molecular weight resin. When the
metal oxide is present at relatively high concentration, e.g., 4-8
wt %, it may be considered to contribute to the structure of the
overall resin. When used for the purpose of resinate formation, the
metal salt or oxide is typically added to the reaction mixture at
about the same time as the polyol is added.
[0219] In an optional aspect, the process for preparing a resin
further comprises charging the reaction vessel with alkaline metal
salt wherein the cation of said salt is divalent. The salt may be
added after formation of the homogeneous molten liquid of resin
acid and fatty acid. Thus, the present invention provides that for
each of the processes and reaction mixture described herein, metal
salt may be added to the reactants to provide a resin of the
present invention. In addition, some small amount of anti-float
agent may be added to the reaction mixture, typically an amount of
less than 0.1 wt %.
[0220] E. Resin Properties
[0221] The resins of the present invention may be characterized by
their properties, which include acid number, melting point,
molecular weight distribution and solubility. These properties are
routinely measured for ink resins, and thus one skilled in the art
is very familiar with techniques to measure these properties.
Nevertheless, a brief description of suitable techniques to measure
certain of these properties is provided here.
[0222] Acid number is measured by dissolving a known weight of
resin (e.g., 1 gram) into an organic solvent (e.g., toluene is a
typical solvent, however a 1:2 ratio weight ratio of
isopropanol:toluene may be used if toluene alone does not dissolve
the resin), and then titrating a measured amount of methanolic
potassium hydroxide (e.g., 0.1 N methanol KOH) solution into the
resin solution. The titration is complete when a pH of about 7 is
attained. This endpoint can be seen by including phenolphthalein in
the solution, where the endpoint occurs when a faint pink color
persists for at least 15 seconds. The acid number of the resin is
equal to the amount of KOH, in mg, which was used in the titration,
divided by the weight of resin, in grams, in the sample that was
titrated. In other words, acid number is equal to the mg of KOH
needed to neutralize 1 gram of sample.
[0223] In various optional aspects of the present invention, the
acid number of the resin is less than about 70, or less than about
60, or less than about 50, or less than about 40, or less than
about 30; or about 1-70, or 1-60, or 1-50, or 1-40, or 1-30, or
about 5-70, or 5-60, or 5-50, or 5-40, or 5-30, or 10-70, or 10-60,
or 10-50, or 10-40, or 10-30, or 15-70, or 15-60, or 15-50, or
15-40, or 15-30. For a resin intended for a lithographic ink
formulation, the acid number of the resin is preferably about
10-30, or about 20. When the acid number is greater than about
30-40, then the resin is rather hydrophilic and will tend to absorb
and/or hold onto water, where this is often disadvantageous when
these resins come into contact with aqueous fountain solutions.
When the resin is intended for a gravure ink formulation, the resin
preferably has an acid number of about 10-60, or about 45. In
practice, reducing acid number below about 10 is expensive and for
this reason is not preferred.
[0224] Melting point, which may also be referred to as "softening
point," may be measured by the so-called "ring and ball" method,
which is the subject of ASTM E28. Alternatively, a softening point
value may be obtained using a softening point instrument from
Mettler Laboratories (Hightstown, N.J., USA). The melting point
values described and reported herein were obtained using a Mettler
FP90/FP83HT Cup and Ball apparatus, according to the following
procedure: A 2.80 mm bottom orifice sample cup is filled with the
molten resin to be tested. The excess resin is removed to give a
flat surface. The solid resin should be free of bubbles. The sample
cup is placed in the cartridge with the lead ball (3.4.+-.0.2 gram)
centered on top of the sample and the cartridge is placed in the
furnace. The following conditions are used: start temperature is
20-25.degree. C. below the expected softening point, heating rate
of 1.5.degree. C./min. Results are reported in .degree. C.
According to this procedure, a resin of the present invention
preferably has a softening point in excess of, in various
embodiments of the invention, 90.degree. C., or 100.degree. C., or
110.degree. C., or 120.degree. C., or 130.degree. C., or
140.degree. C.; while in various additional embodiments the resin
of the present invention has a softening point within a range of:
100-230.degree. C., 110-230.degree. C., 120-230.degree. C.,
130-230.degree. C., 140-230.degree. C., 100-200.degree. C.,
110-200.degree. C., 120-200.degree. C., 130-200.degree. C.,
140-200.degree. C., 100-180.degree. C., 110-180.degree. C.,
120-180.degree. C., 130-180.degree. C., 140-180.degree. C.,
100-160.degree. C., 110-160.degree. C., 120-160.degree. C.,
130-160.degree. C., or 140-160.degree. C. A preferred resin for
lithographic printing has a softening point of about
105-185.degree. C., while a preferred resin for gravure printing
has a softening point of about 135-185.degree. C.
[0225] When the softening point of the resin falls below about
100.degree. C., then it becomes difficult to form flakes from the
resin, where customers for ink resins often prefer the flaked form
of the product. Accordingly, for relatively low softening point
resins, it may be convenient to form a solution of the resin,
rather than flakes.
[0226] A resin of the present invention may be characterized in
terms of its molecular weight, where molecular weight is measured
according to conventional means using gel permeation chromatography
(GPC). GPC analysis may be performed using a Waters model 515 pump
(Waters Instruments, Plymouth, Minn., USA; www.wtrs.com), Waters
model 717 auto injector and Waters 410 differential refractive
index (RI) detector. The components are eluted with a suitable
solvent, e.g., tetrahydrofuran (THF) through suitable column(s),
e.g., a row of 3 Polymer Labs mixed-B GPC columns (Polymer
Laboratories, Amherst, Mass., USA; www.polymerlabs.com). Molecular
weight is determined by comparison of retentions times to a column
calibrated with polystyrene standards. Under these conditions, a
resin of the present invention preferably has a peak molecular
weight within the range of, in various embodiments of the
invention, 30,000-500,000, or 30,000-400,000, or 30,000-300,000, or
80,000-500,000, or 80,000-400,000, or 80,000-300,000, or
120,000-500,000, or 120,000-400,000, or 120-300,000, or
150,000-500,000, or 150,000-400,000, or 150,000-300,000. A
preferred resin of the present invention has a peak molecular
weight of about 200,000.
[0227] A resin of the invention may be characterized in terms of
its solution form. In other words, a solution of the resin in a
suitable solvent is prepared, and this solution is characterized in
order to evaluate the quality of the resin. The solution may be
referred to as a varnish, where the varnish may be used to prepare
an ink. The following procedure may be used to prepare a solution
(varnish) containing a resin of the present invention, where the
varnish itself is an aspect of the present invention. The device
used in this procedure is called a "Thermotronic", and it is
available from Testprint, Inc. (Cherry Hill, N.J., USA;
[0228] www.testprint.com).
[0229] The resin is crushed under mechanical force, and the crushed
resin and a test solvent are weighed into a metal Thermotronic test
tube for a total sample size of 50 grams. The varnish is typically
prepared at a resin solids concentration of 35-50 wt %, preferably
about 45 wt %. The tube is placed in the Thermotronic and a PT-100
temperature probe is inserted. The Thermotronic controllably heats
the solution using the following parameters: stirring speed (RPM)
120; heating rate (.degree. C./minute) 35; top temperature
(.degree. C.) ca. 180-230 C; hold time (minutes) ca. 2-10; cooling
rate (.degree. C./minute) 20. Suitable solvents for this purpose
include M47, TXIB, ARLO, and N40HT, where M47 is MAGIESOL.TM. M-47,
a "technical white oil," from Magie Brothers, Franklin Park, Ill.,
presently a division of Pennzoil Products Company; TXIB is a
plasticizer ester of the chemical name 2,2,4-trimethyl-1,3-pent-
anediol diisobutyrate sold by Eastman Chemical, Kingsport, Tenn.;
ARLO is Alkali Refined Linseed Oil, a commodity chemical; and N40HT
is a specific hydrotreated naphthenic petroleum oil (Chemical
Abstract Service Registry No. 64742-53-6), where many members of
this family of oil are commercially available (see, e.g., San
Joaquin Refining Co., Inc. Bakersfield, Calif., USA).
[0230] Two other suitable solvents are the printing ink distillates
known as PKWF.RTM. and PRINTOSOL.RTM. solvents, both available from
Haltermann Products (a subsidiary of the Dow Company, Channelview,
Tex., USA; www.haltermann.com). PRINTSOL.RTM. 6/9 AR is a
hydrocarbon solvent having a distillation range at 1,013 kPa
according to ISO 3405 or ASTM D 86 of 260-290.degree. C.; a density
at 15.degree. C. according to ISO 12185 or ASTM D 4052 of 875
kg/m.sup.3; an aromatic content of 50% w/w, an aniline point
according to DIN ISO 2977 or ASTM D 611 of 45.degree. C.; a water
content according to ASTM D 1133 of 50, and a refractive index
according to DIN 51423-2 of 1.490 n.sub.D.sup.20; and a pour point
according to DIN ISO 3016 or ASTM D 97 of less than -24.degree. C.
PKWF.RTM. 6/9 is a hydrocarbon solvent having a distillation range
at 1,013 kPa according to ISO 3405 or ASTM D 86 of 260-290.degree.
C.; a density at 15.degree. C. according to ISO 12185 or ASTM D
4052 of 830 kg/m.sup.3; an aromatic content of 20% w/w, an aniline
point according to DIN ISO 2977 or ASTM D 611 of 76.degree. C.; a
water content according to ASTM D 1133 of 27, a refractive index
according to DIN 51423-2 of 1.459; and a pour point according to
DIN ISO 3016 or ASTM D 97 of -18.degree. C. PKWF 6/9.RTM. AF is a
hydrocarbon solvent having a distillation range at 1,013 kPa
according to ISO 3405 or ASTM D 86 of 260-290.degree. C.; a density
at 15.degree. C. according to ISO 12185 or ASTM D 4052 of 777
kg/m.sup.3; an aromatic content of less than or equal to 1% w/w, an
aniline point according to DIN ISO 2977 or ASTM D 611 of 95.degree.
C.; a water content according to ASTM D 1133 of 20, a refractive
index according to DIN 51423-2 of 1.435; and a pour point according
to DIN ISO 3016 or ASTM D 97 of +12.degree. C.
[0231] The solvents may be blended together if desired, e.g., 1:1
M47 and TXIB may be used as the solvent.
[0232] F. Inks and Varnishes
[0233] The present invention provides solutions of the ink resins
of the present invention, including solutions intended to be
components of ink formulations, where these later solutions are
commonly known as varnishes. Varnishes useful in gravure and
lithographic inks may be characterized in terms of their viscosity,
tan delta, and cloud point, among other properties known to one of
ordinary skill in the art. Varnishes for evaluation purposes, such
as for rheological evaluation, may be prepared using the
Thermotronic device described above.
[0234] Rheology flow measurements can be made on a varnish of the
present invention. This measurement can be performed using a TA
Instruments (New Castle, Del., USA; www.tainst.com) AR-1000 N
rheometer in flow mode at 25.degree. C. using a 4 cm 1.degree. cone
set at the geometric gap. A shear rate of 25 s.sup.-1 is applied
for 1 minute with 50 measurement points collected. The final
measurement point is taken as the flow viscosity and is reported in
Pa.s. Under these conditions, a 45 wt % PKWF 6/9 AR solution of a
resin of the present invention preferably has a flow viscosity of
0.1 to 450 Pa.s., or 0.5 to 450 Pa.s., or 5 to 450 Pa.s., or 0.1 to
150 Pa.s., or 0.5 to 150 Pa.s., or 5 to 150 Pa.s. In one aspect, a
varnish of the solution has a flow viscosity of about 5 to 150
Pa.s. for a resin intended for a lithographic ink. In one aspect,
the flow viscosity of the varnish is 20-80 Pa.s.
[0235] Rheology frequency sweep measurements may be used to
determine the tan delta of a varnish of the present invention. This
measurement is made by determining the rheology of the resin
solution with a TA Instruments AR-1000 N rheometer in oscillation
mode at 25.degree. C. using a 4 cm 1.degree. cone set at the
geometric gap. A frequency of 1 Hz is applied using a controlled
strain of 0.10. A temperature sweep is made between 10.degree. C.
and 60.degree. C. over 15 minutes. Tan Delta, G' (Dynes s.sup.-1)
and G" (Dynes s.sup.-1) are reported at 23.degree. C. A varnish of
the present invention may have a tan delta of infinite to 1.3, but
more preferably has a tan delta of less than 5, e.g., 1.3-5.
[0236] Cloud point may be measured in resin solutions according to
standard methods ASTM D97 and SCAN T5:67. The present inventors
prefer to determine cloud point using a Chemotronic Cloud Point
Tester, available from Testprint, Inc. (Cherry Hill, N.J., USA;
www.testprint.com). To measure cloud point, a sample of the resin
is mechanically crushed, and 2.0 g of crushed resin and 18.0 g of
the test solvent are weighed into a Chemotronic glass test tube.
The tube is then placed in the Chemotronic and a PT-100 temperature
probe is inserted. The Chemotronic heats the solution, cools
automatically and reports cloud point in degrees C. The following
parameters are used for all solvent systems: heat to top
temperature of 230.degree. C. at a typical rate of 40.degree.
C./min, hold at 230.degree. C. for 2 minutes, then cool at a
typical rate of 40.degree. C./minute.
[0237] Under these conditions, a clear solution is preferably
produced at a temperature within the range of 25-180.degree. C. For
lithographic printing, the cloud point of the resin may be used as
a guide to determine the type of ink the resin is well suited for.
For example, if the cloud point is low, i.e., below about
50.degree. C., e.g., about 25.degree. C., then the resin has very
good aliphatic solubility and may be used for pigment wetting. If
the cloud point is in the mid-range, i.e., ca. 50-150.degree. C.,
the resin may be particularly useful in heat set lithographic inks.
If the cloud point is high, i.e., over about 150.degree. C., e.g.,
ca. 180.degree. C., the resin may be particularly useful in inks
for sheet fed lithography. For gravure printing, the cloud point of
the resin is not particularly critical, and cloud points in the
range of 25-180.degree. C. are acceptable, where these cloud points
are measured at ca. 10 wt % solids in a solvent. In one aspect, the
resin of the present invention is completely soluble at 180.degree.
C. in mineral oil at a 10% resin solids concentration.
[0238] Particularly when the resin of the present invention is
intended for a component of a gravure printing ink, the toluene
dilutability of the varnish is an important parameter. Toluene
dilution is measured by weighing a known quantity of resinate
solution and diluting it with toluene until print viscosity is
achieved. Print viscosity is determined using a flow or efflux cup
available from a number of manufacturers and standards
organizations. Typical cups used include the Shell #2 and DIN 3 mm
cups, which both are designed to yield the viscosity of press ready
ink at a particular flow time. The known quantity of resinate
solution is diluted to a standard flow time (e.g., 18 seconds on a
Shell #2 cup or 25 seconds on a 3 mm DIN cup) at a standard
temperature (typically 21.degree. C. or 25.degree. C.) and the
amount of toluene is recorded in either mLs or grams per sample
size used. For example, if 75 mLs of toluene was required to reduce
the viscosity of 100 grams of resinate solution to achieve a flow
rate of 18 seconds on a Shell # 2 cup at 25.degree. C., the toluene
dilution would be reported as 75 mLs toluene required to achieve
print viscosity on a Shell #2 cup. In one aspect, a resin of the
present invention has a dilutability of 60-280 mLs toluene, 3 mm
DIN cup at 21.degree. C., starting from 100 grams of a 35% resin
solids toluene solution.
[0239] Another important property for gravure inks is the viscosity
of a solution of the resin. Viscosity is measured on resin or
resinate solutions using a Physica Viscolab LC3 viscometer,
according to the method of ISO 3219 ("Plastics, polymers, resins in
the liquid state or as emulsions of dispersions--Determination of
viscosity using a rotational viscometer with defined shear rate").
Measurements obtained by this method are typically reported in
units of mPa.multidot.s. This viscometer is available from Physica
Messtechnik GmbH, Stuttgart, Germany (www.physica.de). Using a
rotational viscometer, a 35% solid solution of the resin of the
present invention preferably has a viscosity of 50-350
mPa-secs.
[0240] The present invention also provides an ink suitable for
printing, such as gravure or lithographic printing. In gravure
printing, a cylinder onto which is engraved or etched the image to
be printed is rolled directly into ink and transferred directly to
the substrate that accepts the printed image. Gravure printing is a
very common commercial mode of printing, and is well known to one
skilled in the art. Gravure printing is often used in printing on
substrates such as magazine stock, metal foils, plastic films, and
paper cartons.
[0241] A gravure ink of the present invention contains a resin as
disclosed herein, in addition to a solvent, a colorant and optional
performance-enhancing additives. The inventive resin can be used
alone or in combination with co-resins. Suitable co-resins include
commonly known co-resins such as, without limitation, rosin
modified maleic and phenolic esters, hydrocarbon resins and alkyds.
Owing to the lack of intermediary rollers and/or cylinders utilized
in gravure printing, the ink used in gravure printing must be of
very low viscosity and finely ground so as to reduce the amount of
scratching imparted to the engraved or etched cylinder; yet,
because of the relative absence of solvent-sensitive (i.e.,
rubber-composed) moving parts needed for said printing process, a
wide range of solvents are acceptable for use in gravure printing.
Suitable solvents include, without limitation, mineral oils,
aromatic and ester solvents. Suitable colorants include flushed
color, dry pigments and soluble dyes. Additives can include,
without limitation, waxes, wetting agents, and plasticizers. In
addition to the materials noted above, the ink additionally may
contain any number of optional components, where the optional
component(s) provide for improvements in the performance of the
ink. Ink performance properties include color strength, gloss,
scuff resistance, block resistance, misting, open time on press and
many other properties.
[0242] The resins of the present invention are particularly useful
as let down vehicles for gravure inks, e.g., publication gravure
inks. Thus, a pigment dispersion may be prepared using a pigment
and a solution resinate, where solution resinates are well known,
commercially available products currently used for pigment
grinding. After the pigment dispersion has reached a desired state,
e.g., a desired average pigment particle size, the dispersion is
diluted with a letdown vehicle. In addition to diluting the
colorant, the letdown vehicle imparts various desirable properties
to the ink. Desirable properties include gloss and scuff
resistance. The rosin phenolic resin of the present invention,
dissolved in a suitable solvent such as toluene, can be used as a
component of such a letdown vehicle. The rosin phenolic resin will
typically be present at about 30-35% solids in such a vehicle. In
one aspect the present invention provides a phenolic resin as
described herein, in a varnish form.
[0243] Lithographic printing is a process whereby ink is
transferred by rolling onto one or several additional cylinders
before transferring ink onto the substrate, in contrast to gravure
printing, where ink is directly transferred to the substrate. The
lithographic printing process is such that ink is run in
combination with an aqueous solution (known in the art as a
fountain solution), the purpose of the fountain solution being to
wet the parts of the substrate that do not receive ink.
Lithographic printing is also a very common commercial mode of
printing, used in printing on substrates such as packaging
material, and is well known to one of ordinary skill in the
art.
[0244] Lithographic printing is divided into two major types:
sheet-offset, or printing on individual substrate sheets; and
web-offset, or printing on continuous rolls of substrate. Each of
these two major types is further divided into subclasses based on
the mechanism of ink drying. Hence, the properties of a desirable
lithographic ink binder are largely dependent on the specific type
and subclass of printing employed. Some resin properties commonly
desirable for essentially all types of lithographic printing
include high melting point, high viscosity, good solubility in
high-boiling low-solvency aliphatic solvents, good pigment wetting,
and low pigment reactivity.
[0245] In one aspect, the resins of the present invention
demonstrate self-gelling behavior. In other words, they do not
require the presence of metal salt in order to gel a hydrocarbon
solvent. Whether a resin is self-gelling can be determined using a
viscometer, which can measure the viscoelasticity of a mixture of
resin and solvent. In order to determine its viscoelasticity, a
solution of resin and mineral oil is prepared by mixing the
components for 30 minutes at 180.degree. C. in a weight ratio of
resin:mineral oil of 1:1.5. The mineral oil should have a boiling
range of 240-270.degree. C. and an aniline point of 72.degree. C.
(standard mineral oil PKW F 4/7, supplier: Haltermann). This
mixture is cooled to room temperature, and the tan delta of the
solution is measured using a viscometer. For instance, an
oscillating rotary viscometer (RV 20/CV 100 apparatus from Haake
using measuring device (cone) PK 20 at 23.degree. C., a deflection
angle of 100, a frequency sweep of 0.05 to 5 Hz, and an angular
velocity range (omega) of 1-10 s.sup.-1 gives tan delta value of
<5 for a self-gelling resin.
[0246] Printing ink may be prepared by adding colorant (e.g., flush
color, dry pigment or soluble dyes), additives and additional
solvent to a letdown varnish comprising a resinate composition of
the present invention. Flush color is a form of pigment where the
solvent used during the pigment manufacturing process (water) has
been replaced by a hydrocarbon or oil based varnish. Such a varnish
can contain the inventive or conventional resins, resinates, or a
combination of both. Finished ink may be prepared by adding the
flush color and the letdown varnish while mixing at low shear. The
mixture can be passed through a bead mill or shot mill to further
reduce pigment particle size and improve final ink properties.
Soluble dyes can be added with little or no additional energy to
impart color to the system. Additional varnish or solvent can be
added to adjust tack, flow and viscosity to reach target
specifications and then additives are blended in.
[0247] The following are some other optional components that may be
included in an ink of the present invention. Blown Castor Oil (BCO)
may be included at a level of, e.g., 1-3 wt % in order to reduce
the water pickup of the ink. Soybean oil (SBO) is often used in
inks in order to reduce their tack, and to increase the flowability
of an ink, where a typical concentration is 1-10 wt %. Tung oil may
be included in an ink formulation at a concentration of about 5-15
wt % in order increase the setting speed of an ink. Tung oil may
also increase the hardness of the dried ink. Tung oil, like SBO,
can also increase the flowability of an ink, and reduce its tack.
Alkali Refined Linseed Oil (ARLO) is extracted from the seed of the
flax plant, and consists largely of linolenic acid. ARLO can be
used for cutting tack and body, increasing flow of overly "short"
inks, and to enhance the film integrity of inks that contain
metallic driers that can react with ARLO. The addition of Gelled
Linseed Oil (GLO) to an ink is a convenient way to reduce the tack
of a heavy ink, particularly sheetfed or web offset inks. Each of
these oils is a commodity chemical and readily available from many
commercial suppliers.
[0248] One skilled in the art is familiar with preparing printing
inks using either flush color, dry pigment or soluble dyes, and may
adopt other procedures for preparing such a printing ink using a
resin of the present invention. Accordingly, the following examples
provide illustrations of the present invention, and are not a
limitation thereon.
EXAMPLES
[0249] The invention is illustrated in more detail by the following
examples. In the following examples, chemicals were of reagent
grade unless noted otherwise, and were obtained from commercial
supply houses such as Aldrich Chemical Co. (Milwaukee, Wis.).
SYLVAROS.TM. 85 tall oil rosin, SYLFAT.TM. 2S tall oil fatty acid,
and CENTURY MO6.TM. Monomer are available from Arizona Chemical
(Jacksonville, Fla.). Chinese gum rosin is available from sources
such as BFB Enterprises (Panama City Beach, Fla.). Test oils 6/9
and 6/9 AR are mineral oils available from Haltermann Products
(Channelview, Tex.). When a value is recited such as "45% AR", this
refers to a solution of the resin in 6/9 AR test oil, at 45 wt %
solids (100.times.weight of resin divided by the sum of the weights
of the resin and the solvent).
[0250] In the Tables, "%" refers to weight percent of a particular
reactant based on the total weight of the reactants.
Example 1
Rosin Modified Phenolic Ester
[0251] As summarized in TABLE 1, a reaction vessel was charged with
Chinese gum rosin, CENTURY MO6.TM. Monomer, and phenol, and heated
to about 150-170.degree. C. After the mixture was molten, the
vessel was further charged with magnesium oxide catalyst (dispersed
in about 15 grams xylene), and the resulting admixture was cooled
to about 110.degree. C. The reaction vessel was charged with 91%
paraformaldehyde, and the resulting admixture was refluxed at about
120.degree. C. for about 90 minutes, before heating to about
270.degree. C. (@ 35.degree. C./hr) to allow removal of condensed
water and drive the reaction to completion.
1TABLE 1 Composition Of Rosin Monomer Phenolic Resin CAS No.
Component Weight Percent 8050-09-7 Chinese Gum Rosin 58.16 108-95-2
Phenol 14.54 30525-89-4 Paraformaldehyde, 91% 15.31 68955-98-6
CENTURY MO6 .TM. Monomer 11.63 1309-48-4 Magnesium Oxide 0.36 Total
charge (grams): 825.36 Final Softening Point (.degree. C.): 155
Final Acid Number (mg KOH/g): 56
Examples 2-4
Rosin Modified Phenolic Ester
[0252] These examples describe the preparation of rosin modified
phenolic esters suitable for use in lithographic varnish
manufacture, according to the weight percentages indicated in TABLE
2.
[0253] A reaction vessel was charged with Chinese gum rosin, tall
oil rosin, CENTURY MO6.TM. Monomer, and phenol, and heated to about
150-170.degree. C. After melting the rosin, the vessel was further
charged with magnesium oxide catalyst (dispersed in about 10 grams
xylene), and the resulting admixture was cooled to about
110.degree. C. The reaction vessel was then further charged with
91% paraformaldehyde, the resulting admixture was allowed to reflux
at about 110-120.degree. C. for about 90 minutes, before heating to
about 155.degree. C. to allow removal of condensed water. The
reaction vessel was then further charged with maleic anhydride, and
the resulting admixture was heated to 210.degree. C. The reaction
vessel was then further charged with mono-pentaerythritol, and the
resulting admixture was heated to about 270.degree. C., to allow
removal of water produced from esterification. The reaction product
was sampled hourly at 270.degree. C. for viscosity in mineral oil
and cloud point from mineral oil solution. Optionally, the reaction
mixture was held at about 150.degree. C. overnight, before
reheating the mixture to 270.degree. C. and proceeding with
sampling as above. Upon reaching the desired level of viscosity and
solids, the reaction mixture was cooled to about 250.degree. C. and
discharged.
2TABLE 2 Composition Of Rosin Modified Phenolic Ester Weight
Percent CAS No. Component Ex. 2 Ex. 3 Ex. 4 8050-09-7 Chinese Gum
Rosin 43.85 47.48 44.2 8052-10-6 SYLVAROS .TM. 85 18.79 20.35 19.0
Tall Oil Rosin 108-95-2 Phenol 8.50 5.52 8.6 30525-89-4
Paraformaldehyde, 91% 6.94 4.50 7.0 68955-98-6 CENTURY 11.33 7.01
10.6 MO6 .TM. Monomer 1309-48-4 Magnesium Oxide 0.15 0.11 0.1
108-31-6 Maleic Anhydride 1.22 3.78 1.2 115-77-5
Mono-Pentaerythritol 9.22 11.26 9.2 Total charge (grams): 2472
1141.6 1225 Final Softening Point 130 150 138 (.degree. C.): Final
Viscosity 37.9 32.2 42.2 45% AR (Pa .multidot. s): Rheology Tan
5.186 n.d. 5.522 delta, 23.degree. C., 45% AR: Final Cloud Point
(.degree. C.): 109 126 119 Final Acid Number 19.3 20.3 22.3 (mg
KOH/g):
Example 5
Rosin Modified Phenolic Ester
[0254] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 3 where charged to a reaction
vessel.
3TABLE 3 Resin-Forming Reaction Mixture Weight Weight % Gum Rosin
487.8 g 43.1% Tall Oil Rosin 209 g 18.5% Monomer 144 g 12.7% Phenol
94.5 g 8.4% MgO 1.6 g 0.2% Paraform 86.2 7.6% Maleic Anhydride 7.8
g 0.7% Pentaerythritol 100.5 g 8.8% Total Charge 1,131.4 g 100%
[0255] The resin of Example 5 had a cloud point as measured at 10
wt % in test oil of 105.degree. C., a viscosity at 23.degree. C. as
measured for a 45 wt % solution in test oil of 26.2 Pascal, and an
acid value of 20.6.
Examples 6-8
Rosin Modified Phenolic Ester
[0256] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 4 were charged to a reaction
vessel. The resulting resins had final values for viscosity,
rheology and cloud point as indicated in TABLE 4. The data in Table
4 show that both viscosity and cloud point increase with increasing
phenol level.
4TABLE 4 Composition and Properties of Rosin Modified Phenolic
Ester Example Number 6 7 8 Chinese Gum Rosin (%) 46 45.5 45
SYLVAROS .TM. 85 Tall Oil Rosin (%) 20 19.5 19 MO6 (%) 10 10 10
Phenol (%) 7.5 8 8.5 Paraformaldehyde (%) 7.8 8.3 8.8 F/P 3 3 3
Pentaerythritol (%) 8.6 8.5 8.4 OH excess 10 10 10 Magnesium Oxide
(%) 0.2 0.2 0.2 Maleic Anhydride (%) 0 0 0 Cloud Point 10% 6/9
(.degree. C.) 81 114 126 Viscosity 35% 6/9 AR Blend (Pa .multidot.
s) 0.68 2.43 6.3 Tan delta, 35% 6/9 AR Blend, 23.degree. C.
infinite 126.9 11.23 Tan delta, 35% 6/9 AR Blend, 41.degree. C.
infinite Infinite infinite Tan delta, 35% 6/9 AR Blend, 60.degree.
C. infinite Infinite infinite
Examples 9-11
Rosin Modified Phenolic Ester
[0257] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 5 were charged to a reaction
vessel. The resulting resins had final values for viscosity,
rheology and cloud point as indicated in TABLE 5. Relative to TABLE
4, the higher phenol levels used in Examples 9-11 provided resins
that yielded higher solution viscosity and lower tan deltas. A
higher Monomer level was used to maintain cloud point at the higher
viscosity level. These resins are useful, for example, in sheetfed
applications.
5TABLE 5 Composition and Properties of Rosin Modified Phenolic
Ester Example Number 9 10 11 Chinese Gum Rosin (%) 37 37 37
SYLVAROS .TM. 85 Tall Oil Rosin (%) 16 16 16 MO6 (%) 20 20 20
Phenol (%) 9.5 9.5 9.5 Paraformaldehyde (%) 8.4 8.4 8.4 F/P 2.5 2.5
2.5 Pentaerythritol (%) 8.3 8.5 8.7 OH excess 10 10 10 Magnesium
Oxide (%) 0.2 0.2 0.2 Maleic Anhydride (%) 0 0.25 0.5 Cloud Point
10% 6/9 (.degree. C.) 82 112 119 Viscosity 35% 6/9 AR Blend (Pa
.multidot. s) 13.7 20.4 33.3 Tan delta, 35% 6/9 AR Blend,
23.degree. C. 2.767 2.758 1.926 Tan delta, 35% 6/9 AR Blend,
41.degree. C. 11.57 12.29 4.077 Tan delta, 35% 6/9 AR Blend,
60.degree. C. infinite Infinite 45.58
Examples 12-14
Rosin Modified Phenolic Ester
[0258] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 6 were charged to a reaction
vessel. The resulting resins had final values for viscosity,
rheology and cloud point as indicated in TABLE 6. Relative to the
Examples of Table 5, the reactions described in TABLE 6 utilize a
higher Monomer level to yield resins with cloud points below
70.degree. C. These resins are useful, for example, in heatset
applications and pigment wetting applications.
6TABLE 6 Composition and Properties of Rosin Modified Phenolic
Ester Example Number 12 13 14 Chinese Gum Rosin (%) 30 30 30
SYLVAROS .TM. 85 Tall Oil Rosin (%) 13 13 13 MO6 (%) 30 30 30
Phenol (%) 9.5 9.5 9.5 Formaldehyde (%) 8 8 8 F/P 2.5 2.5 2.5
Pentaerythritol (%) 8.4 8.5 8.7 OH excess 10 10 10 Magnesium Oxide
(%) 0.2 0.2 0.2 Maleic Anhydride (%) 0 0.25 0.5 Cloud Point 10% 6/9
(.degree. C.) 42 47 63 Viscosity 35% 6/9 AR Blend (Pa .multidot. s)
3.7 3.8 9.4 Tan delta, 35% 6/9 AR Blend, 23.degree. C. 2.416 Tan
delta, 35% 6/9 AR Blend, 41.degree. C. 5.262 Tan delta, 35% 6/9 AR
Blend, 60.degree. C. infinite
Examples 15-17
Rosin Modified Phenolic Ester
[0259] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 7 were charged to a reaction
vessel. The resulting resins had final values for viscosity,
rheology, and cloud point as indicated in TABLE 7. Relative to
Table 6, the reactions described in Table 7 had higher phenol and
Monomer loadings to yield usable viscosities at even lower could
points. These resins are suitable in, for example, heatset and
pigment wetting applications.
7TABLE 7 Composition of Rosin Modified Phenolic Ester Example
Number 15 16 17 Chinese Gum Rosin (%) 26 26 26 SYLVAROS .TM. 85
Tall Oil Rosin (%) 11 11 11 MO6 (%) 35 35 35 Phenol (%) 10 10.5 11
Paraformaldehyde (%) 8.7 9.0 9.5 F/P 2.5 2.5 2.5 Pentaerythritol
(%) 8 8 8 OH excess 10 10 10 Magnesium Oxide (%) 0.2 0.2 0.2 Maleic
Anhydride (%) 0 0 0 Cloud Point 10% 6/9 (.degree. C.) 35 45 101
Viscosity 35% 6/9 AR Blend (Pa .multidot. s) 1.2 4.6 11.9 Tan
delta, 35% 6/9 AR Blend, 23.degree. C. 1.931 1.901 Tan delta, 35%
6/9 AR Blend, 41.degree. C. 3.058 3.693 Tan delta, 35% 6/9 AR
Blend, 60.degree. C. 7.734 30.79
Examples 18-24
Rosin Modified Phenolic Ester
[0260] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 8 were charged to a reaction
vessel. Each of these sets of reactants provided a gelled product
within the indicated time. Gellation occurred because one or more
of the functional components (phenol, paraformaldehyde or maleic
anhydride) was present at too high of a concentration in the
reaction vessel.
[0261] A resin of the present invention preferably is not a gelled
resin, and is not in admixture with gelled resin. In a preferred
aspect, a resin of the present invention may be dissolved at
elevated temperature in xylene at a 10 wt % concentration, and upon
cooling, a bright, clear solution results. This is indicative of a
resin that does not contain any gel.
8TABLE 8 Composition of Rosin Modified Phenolic Ester Weight
percent Component Ex. 18 Ex. 19 Ex. 20 Ex. 21 Ex. 22 Ex. 23 Ex. 24
Chinese Gum Rosin 37.31 30.21 30.30 27.20 27.09 27.04 29.11
SYLVAROS .TM. 85 15.99 12.95 12.99 11.66 11.61 11.59 12.47 Tall Oil
Rosin Phenol 9.87 9.92 9.56 9.23 9.19 9.17 10.89 Paraformaldehyde,
8.64 8.68 8.40 8.10 8.07 8.05 9.53 91% CENTURY MO6 .TM. 19.74 29.76
30.20 34.01 33.87 33.79 29.70 Monomer Magnesium Oxide 0.20 0.20
0.20 0.19 0.19 0.19 0.20 Maleic Anhydride -- -- -- 0.97 1.45 1.45
-- Pentaerythritol 8.27 8.28 8.36 8.63 8.52 8.71 8.10 Sampling time
when 7 hrs 4 hrs 5 hrs 3 hrs 2 hrs 2 hrs 4 hrs gel discovered:
Examples 25-36
Rosin Modified Phenolic Ester
[0262] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 9 were charged to a reaction
vessel. Each of these sets of reactants provided a gelled product
within the indicated time. As with Examples 18-24, gellation
occurred because one or more of the functional components (phenol,
paraformaldehyde or maleic anhydride) was present at too high of a
concentration in the reaction vessel. As indicated in the previous
set of Examples, a resin of the present invention preferably is not
a gelled resin, and is not in admixture with gelled resin.
9TABLE 9 Composition of Rosin Modified Phenolic Ester Weight
Percent Component Ex. 25 Ex. 26 Ex. 27 Ex. 28 Ex. 29 Ex. 30 Ex. 31
Ex. 32 Ex. 33 Ex. 34 Ex. 35 Ex. 36 Chinese Gum Rosin 50.00 43.04
36.09 29.13 22.07 32.76 25.78 18.80 22.87 15.67 30.14 22.97
SYLVAROS .TM. 21.43 18.45 15.47 12.49 9.47 14.04 11.05 8.06 9.80
6.72 12.92 9.85 85 Tall Oil Rosin Phenol 9.92 9.92 9.91 9.91 9.93
12.45 12.44 12.44 9.40 9.45 9.11 9.28 Paraformaldehyde, 10.44 10.43
10.43 10.43 10.45 13.09 13.09 13.08 9.89 9.94 9.59 9.77 91% CENTURY
MO6 .TM. -- 9.92 19.83 29.73 39.73 19.91 29.86 39.80 39.60 49.75
29.77 39.66 Monomer Magnesium Oxide 0.20 0.20 0.20 0.20 0.20 0.20
0.20 0.20 0.20 0.20 0.20 0.20 Pentaerythritol 8.02 8.05 8.08 8.12
8.15 7.56 7.59 7.62 8.25 8.27 8.28 8.27 Sampling time when 4 hrs 4
hrs 4 hrs 4 hrs 2 hrs <2 hrs <2 hrs <2 hrs 4 hrs 2 hrs 4
hrs 5 hrs gel discovered:
Examples 37-50
Rosin Modified Phenolic Ester
[0263] Following essentially the same procedure as set forth in
Examples 1-4, the reactants of TABLE 10 were charged to a reaction
vessel. The resulting resins had final values for viscosity,
rheology, cloud point, molecular weight, softening point, and acid
number as indicated in TABLE 10. The reaction conditions of Table
10 illustrate, for example, the effect of including maleic
anhydride among the reactants.
10TABLE 10 Composition and Properties of Rosin Modified Phenolic
Ester Weight Percent Component Ex. 37 Ex. 38 Ex. 39 Ex. 40 Ex. 41
Ex. 42 Chinese Gum Rosin 37.36 37.20 30.30 30.03 30.21 23.25
SYLVAROS .TM. 85 16.01 15.94 12.99 12.87 12.95 9.97 Tall Oil Rosin
Phenol 9.57 9.52 9.56 9.48 9.92 9.92 Paraformaldehyde, 8.40 8.36
8.40 8.32 8.68 8.86 91% CENTURY MO6 .TM. 20.14 20.05 30.20 29.93
29.76 39.67 Monomer Magnesium Oxide 0.20 0.20 0.20 0.20 0.20 0.20
Maleic Anhydride -- 0.25 -- 0.50 -- -- Pentaerythritol 8.32 8.47
8.36 8.66 8.28 8.32 Mn (average, amu): 2209 1629 1950 1612 n.d.
n.d. Mw (weight-average, 369722 240487 389453 178458 n.d. n.d.
amu): Final Acid Number n.d. 24.8 n.d. n.d. 20.4 22.8 (mg KOH/g):
Softening pt (.degree. C.) 137 131 117 124 119 169 VISCOSITY (Pa
.multidot. s) AR Blend 13.7/ 20.4/ 3.7/ 9.4/ 7.5/ 5.5/ (35%/45%)
n.d. n.d. 12.7 n.d. 23.9 n.d. 50% M47: n.d. n.d. n.d. n.d. 132.8
n.d. CLOUD POINT (.degree. C.) 10% 6/9: 82 112 42 63 53 36 10% 6/9
AF: n.d. n.d. n.d. n.d. n.d. 168 10% 6/9 AFN: 162 n.d. 108 162 131
n.d. RHEOLOGY TAN DELTA (35% AR Blend) 23.degree. C.: 2.767 2.758
n.d. 2.416 2.209 1.770 41.degree. C.: 11.57 12.29 n.d. 5.262 4.516
2.445 60.degree. C.: infinite infinite n.d. infinite 52.68 3.937
Weight Percent Component Ex. 43 Ex. 44 Ex. 45 Ex. 46 Ex. 47 Ex. 48
Ex. 49 Ex. 50 Chinese Gum Rosin 29.75 22.82 26.77 26.44 25.64 30.08
29.95 29.62 SYLVAROS .TM. 85 12.75 9.78 11.47 11.33 10.99 12.89
12.83 12.69 Tall Oil Rosin Phenol 10.38 10.37 9.91 10.33 10.89 9.88
9.83 10.33 Paraformaldehyde, 9.08 9.08 8.67 9.04 9.53 8.64 8.61
9.04 91% CENTURY MO6 .TM. 29.65 39.52 34.68 34.43 34.64 29.63 29.50
29.52 Monomer Magnesium Oxide 0.20 0.20 0.20 0.20 0.20 0.20 0.20
0.20 Maleic Anhydride -- -- -- -- -- 0.25 0.49 0.25 Pentaerythritol
8.20 8.23 8.31 8.22 8.12 8.44 8.59 8.36 Mn (average, amu): n.d.
n.d. n.d. n.d. n.d. n.d. n.d. n.d. Mw (weight-average, n.d. n.d.
n.d. n.d. n.d. n.d. n.d. n.d. amu): Final Acid Number n.d. n.d.
n.d. n.d. n.d. 24.2 23.2 n.d. (mg KOH/g): Softening pt (.degree.
C.) 127 148 131 n.d. 134 109 167 139 VISCOSITY (Pa .multidot. s) AR
Blend 8.5/ 6.5/ 1.2/ 4.6/ 11.9/ 5.2/ 14.3/ 19.6/ (35%/45%) 27.8
16.9 n.d. n.d. n.d. n.d. n.d. n.d. 50% M47: 133.0 n.d. 66.4 n.d.
n.d. n.d. n.d. n.d. CLOUD POINT (.degree. C.) 10% 6/9: 71 45 35 45
101 50 67 91 10% 6/9 AF: 210 210 172 n.d. n.d. n.d. n.d. n.d. 10%
6/9 AFN: 159 143 116 n.d. n.d. n.d. n.d. n.d. RHEOLOGY TAN DELTA
(35% AR Blend) 23.degree. C.: 2.221 1.931 n.d. 1.931 1.901 3.008
1.389 1.544 41.degree. C.: 4.267 3.058 n.d. 3.058 3.693 8.248 1.726
2.204 60.degree. C.: 27.84 7.734 n.d. 7.734 30.79 infinite 2.254
3.971
Example 51
Rosin Modified Phenolic Ester
[0264] This example describes the preparation of rosin modified
phenolic esters suitable for use in publication gravure varnish
manufacture, according to the weight percentages indicated in TABLE
11.
[0265] A reaction vessel was charged with tall oil rosin, and
CENTURY MO6.TM. Monomer under inert gas sparge. After melting the
rosin, the admixture was cooled to about 110.degree. C., and the
vessel was further charged with a slurry of magnesium oxide
catalyst (dispersed in xylene). The reaction vessel was then
further charged with additional xylene (used to collect residual
slurry), phenol, polymethylsiloxane, and 91% paraformaldehyde, and
the resulting admixture was allowed to reflux at about
110-120.degree. C. for about 2 hours, charging the vessel with
additional polymethylsiloxane as needed to reduce foaming. The
reaction mixture was then heated to about 210.degree. C. and the
reaction vessel was further charged with antifloat liquid and
pentaerythritol. The resulting admixture was then heated to about
270.degree. C., to allow removal of water produced from
esterification. After reaching 270.degree. C. (or after about 6
hours of heating to a temperature of 270.degree. C.), the reaction
product was sampled hourly for viscosity in mineral oil and cloud
point from mineral oil solution. Upon reaching the desired level of
viscosity and solids, the reaction mixture was cooled to about
250.degree. C. and discharged.
11TABLE 11 Composition Of Rosin Modified Phenolic Ester Weight CAS
No. Component Percent 8052-10-6 SYLVAROS .TM. 85 Tall Oil Rosin
52.32 108-95-2 Phenol 9.38 30525-89-4 Paraformaldehyde, 91% 8.23
68955-98-6 CENTURY MO6 .TM. Monomer 19.74 1309-48-4 Magnesium Oxide
(MgO) 0.20 1330-20-7 Xylene for dispersing MgO 1.22 1330-20-7
Xylene for slurry wash 1.22 Polymethylsiloxane <0.01 (1% in
white spirit) Troykyd antifloat liquid (AFL) <0.01 115-77-5
Pentaerythritol 7.68 Total charge (kg): 22200 Final Softening Point
(.degree. C.): 136 Final Viscosity 35% in toluene, mPa .multidot.
s): 175 Appearance: Clear Final Acid Number (mg KOH/g): 20
Example 52
Rosin Modified Phenolic Ester
[0266] This example describes the preparation of rosin modified
phenolic esters suitable for use in lithographic varnish
manufacture, according to the weight percentages indicated in TABLE
12.
[0267] A reaction vessel was charged with gum rosin, tall oil
rosin, and CENTURY MO6.TM. Monomer under inert gas sparge. After
melting the rosin, the admixture was cooled to about 110.degree.
C., and the vessel was further charged with a slurry of magnesium
oxide catalyst (dispersed in xylene). The reaction vessel was then
further charged with additional xylene (used to collect residual
slurry), phenol, polymethylsiloxane, and 91% paraformaldehyde, and
the resulting admixture was allowed to reflux at about
105-120.degree. C. for about 90 minutes, charging the vessel with
additional polymethylsiloxane as needed to reduce foaming. The
reaction mixture was then heated to about 155.degree. C. and the
reaction vessel was further charged with maleic anhydride. The
reaction mixture was then heated to about 210.degree. C. and the
reaction vessel was further charged with antifloat liquid and
pentaerythritol, such that the pentaerythritol was added no sooner
than 90 minutes after addition of maleic anhydride. The resulting
admixture was then heated to about 270.degree. C., to allow removal
of water produced from esterification. After reaching 270.degree.
C. (or after about 6 hours of heating to a temperature of
270.degree. C.), the reaction product was sampled hourly for
viscosity in mineral oil and cloud point from mineral oil solution.
Upon reaching the desired level of viscosity and solids, the
reaction mixture was cooled to about 250.degree. C. and
discharged.
12TABLE 12 Composition Of Rosin Modified Phenolic Ester Weight CAS
No. Component Percent 8050-09-7 Chinese gum rosin 41.55 8052-10-6
SYLVAROS .TM. 85 Tall Oil Rosin 17.81 108-95-2 Phenol 8.85
30525-89-4 Paraformaldehyde, 91% 7.45 68955-98-6 CENTURY MO6 .TM.
Monomer 14.57 1309-48-4 Magnesium Oxide (MgO) 0.14 108-31-6 Maleic
anhydride 0.77 Polymethylsiloxane (1% in white spirit) <0.01
Troykyd antifloat liquid (AFL) <0.01 115-77-5 Pentaerythritol
8.93 Total charge (kg): 22203 Final Softening Point (.degree. C.):
140 Final Viscosity 45% AR (Pa .multidot. s): 23 Cloud Point
(.degree. C.): 96 Appearance: Clear Final Acid Number (mg KOH/g):
19
[0268] All of the above U.S. patents, U.S. patent application
publications, U.S. patent applications, foreign patents, foreign
patent applications and non-patent publications referred to in this
specification and/or listed in the Application Data Sheet, are
incorporated herein by reference, in their entirety.
[0269] From the foregoing it will be appreciated that, although
specific embodiments of the invention have been described herein
for purposes of illustration, various modifications may be made
without deviating from the spirit and scope of the invention.
Accordingly, the invention is not limited except as by the appended
claims.
* * * * *
References