U.S. patent application number 13/184085 was filed with the patent office on 2011-11-17 for low molecular weight cellulose mixed esters and their use as low viscosity binders and modifiers in coating compositions.
This patent application is currently assigned to EASTMAN CHEMICAL COMPANY. Invention is credited to Daniel Wayne Dixon, JR., Roy Glenn Foulk, Charlie Carroll Freeman, JR., Jonathan Edward Lawniczak, Paul Lee Lucas, Luis Guillermo Rios Perdomo, Hieu Duy Phan, Jessica Dee Posey-Dowty, Michael Charles Shelton, Kenneth Raymond Walker, Alan Kent Wilson.
Application Number | 20110282049 13/184085 |
Document ID | / |
Family ID | 33029945 |
Filed Date | 2011-11-17 |
United States Patent
Application |
20110282049 |
Kind Code |
A1 |
Shelton; Michael Charles ;
et al. |
November 17, 2011 |
LOW MOLECULAR WEIGHT CELLULOSE MIXED ESTERS AND THEIR USE AS LOW
VISCOSITY BINDERS AND MODIFIERS IN COATING COMPOSITIONS
Abstract
Cellulose mixed esters are disclosed having low molecular
weights and low degrees of polymerization. These new cellulose
mixed esters include cellulose acetate propionate and cellulose
acetate butyrate. The esters exhibit solubility in a wide range of
organic solvents with minimal viscosity increase, are compatible
with a wide variety of resins, and are useful in coatings and inks
compositions as binder resins and rheology modifiers.
Inventors: |
Shelton; Michael Charles;
(Kingsport, TN) ; Posey-Dowty; Jessica Dee;
(Kingsport, TN) ; Perdomo; Luis Guillermo Rios;
(Kingsport, TN) ; Dixon, JR.; Daniel Wayne;
(Church Hill, TN) ; Lucas; Paul Lee; (Gray,
TN) ; Wilson; Alan Kent; (Kingsport, TN) ;
Walker; Kenneth Raymond; (Dunblane, GB) ; Lawniczak;
Jonathan Edward; (Kingsport, TN) ; Foulk; Roy
Glenn; (Kingsport, TN) ; Phan; Hieu Duy;
(Antioch, IL) ; Freeman, JR.; Charlie Carroll;
(Rogersville, TN) |
Assignee: |
EASTMAN CHEMICAL COMPANY
Kingsport
TN
|
Family ID: |
33029945 |
Appl. No.: |
13/184085 |
Filed: |
July 15, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12519324 |
Feb 8, 2010 |
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13184085 |
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10796176 |
Mar 9, 2004 |
7585905 |
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12519324 |
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60455033 |
Mar 14, 2003 |
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Current U.S.
Class: |
536/58 |
Current CPC
Class: |
C09D 175/04 20130101;
C09D 201/00 20130101; Y10T 428/31703 20150401; Y10T 428/31982
20150401; C09D 101/14 20130101; C08B 13/00 20130101; C08B 3/18
20130101; C09D 175/04 20130101; C08L 1/32 20130101; C08G 18/6484
20130101; C08B 3/16 20130101; C09D 101/14 20130101; C09D 201/00
20130101; C08L 2666/26 20130101; C08L 1/14 20130101; C08L 2666/02
20130101; C08L 2666/20 20130101 |
Class at
Publication: |
536/58 |
International
Class: |
C08B 3/18 20060101
C08B003/18 |
Claims
1. A cellulose mixed ester having the following properties: a total
degree of substitution per anhydroglucose unit of from 3.08 to
3.50, having the following substitutions: a degree of substitution
per anhydroglucose unit of hydroxyl of no more than about 0.70, a
degree of substitution per anhydroglucose unit of C.sub.3-C.sub.4
esters from about 0.80 to about 1.40, and a degree of substitution
per anhydroglucose unit of acetyl of from about 1.20 to about 2.34;
an inherent viscosity of from 0.05 to 0.12 dL/g, as measured in a
60/40 (wt./wt.) solution of phenol/tetrachloroethane at 25.degree.
C.; a number average molecular weight (M.sub.n) of from about 1,000
to about 5,600; a weight average molecular weight (M.sub.w) of from
about 1,500 to about 10,000; and a polydispersity of from about 1.2
to about 3.5.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/510,324, now allowed, which claims priority
to U.S. patent application Ser. No. 10/796,176, filed Mar. 9, 2004
and issued as U.S. Pat. No. 7,585,905, which claims priority to
U.S. Provisional Patent Application No. 60/455,033, filed Mar. 14,
2003, the disclosure of which is incorporated herein by reference
in its entirety.
FIELD OF THE INVENTION
[0002] This invention belongs to the field of cellulose chemistry,
and more particularly, to low molecular weight cellulose mixed
esters that are useful in coating and ink compositions as low
viscosity binder resins and rheology modifiers.
BACKGROUND OF THE INVENTION
[0003] Cellulose esters are valuable polymers that are useful in
many plastic, film, coating, and fiber applications. Cellulose
esters (CEs) are typically synthesized by the reaction of cellulose
with an anhydride or anhydrides corresponding to the desired ester
group or groups, using the corresponding carboxylic acid as diluent
and product solvent. Some of these ester groups can afterward be
hydrolyzed to obtain a partially-esterified product. These
partially substituted cellulose esters have great commercial value,
and find use in coatings, where their greater solubility and
compatibility with co-resins (in comparison with triesters) and
hydroxyl group content (to facilitate crosslinking) are prized.
[0004] An important aspect in obtaining suitable cellulose esters
has traditionally been maintaining molecular weight during the
esterification process. A loss in molecular weight is associated
with poor plastic properties and brittle films, a flexible film
being the desired goal. Thus, it has long been recognized that in
order to obtain a suitable chloroform-soluble (triacetate)
cellulose ester, the acetylation process must not result in
significant degradation, or lowering of the molecular weight, of
the cellulose. See, for example, U.S. Pat. No. 1,683,347.
[0005] When it was discovered that these early triacetate esters
could be modified, via partial hydrolysis of the acetate groups, to
obtain acetone-soluble cellulose acetate, maintaining a suitable
molecular weight during hydrolysis remained important. See, for
example, U.S. Pat. No. 1,652,573. It was recognized as early as the
1930's that the amount of hydrochloric acid present in the reaction
mixture during partial ester hydrolysis must be carefully
controlled to avoid hydrolysis or breakdown of the cellulose
acetate. See, for example, U.S. Pat. No. 1,878,954.
[0006] Likewise, U.S. Pat. No. 2,129,052 advised that hydrolysis
under severe conditions such as high temperature or high
concentration of catalyst caused degradation of the cellulose, the
resulting products being unsuitable for commercial use because of
their low strength. U.S. Pat. No. 2,801,239, relating to the use of
zinc chloride as an esterification catalyst, cited as an advantage
that the process minimized the rate of breakdown of the cellulose.
U.S. Pat. No. 3,518,249 acknowledged that little interest had been
shown in cellulose esters of an extremely low degree of
polymerization. More recently it was confirmed that the rate of
hydrolysis in cellulose esters is controlled by temperature,
catalyst concentration, and, to a lesser extent, by the amount of
water, and that higher water content slightly increases the rate of
hydrolysis and "helps minimize degradation." Kirk-Othmer,
Encyclopedia of Chemical Technology, Fourth Ed., vol. 5, pp.
496-529, 509 (1993), John Wiley & Sons, New York, N.Y.
[0007] When used in coating compositions, conventional cellulose
esters provide many benefits, including improved hardness, improved
aluminum flake orientation, high clarity, high gloss, decreased
dry-to-touch time, improved flow and leveling, improved redissolve
resistance, reduced cratering, and reduced blocking. However, the
performance properties of conventional cellulose esters are
accompanied by an increase in viscosity, which must be offset by
increasing the level of solvents used. With recent concerns of VOC
levels in coating compositions, there remains a need for a
cellulose ester product that provides the benefits of conventional
cellulose esters, while providing only a moderate increase in
viscosity without the addition of organic solvents. It would
clearly be an advance in the art to provide cellulose esters that
provide the performance properties of conventional cellulose
esters, without an undue increase in viscosity when incorporated
into coating compositions.
[0008] Although maintaining the molecular weight of cellulose
esters during esterification and partial hydrolysis has long been
deemed important in obtaining a suitable product, there has
nonetheless been occasional mention in the literature of lower
molecular weight cellulose esters.
[0009] For example, U.S. Pat. No. 3,386,932 discloses a method for
reducing the molecular weight of cellulose triacetate with a
catalyst such as boron trifluoride, the resulting bifunctional, low
molecular weight cellulose triacetate then being used to produce
linear block copolymers. This disclosure emphasizes the importance
of maintaining the ester substitution at the 2-, 3-, and
6-positions of the triacetate, that is, wherein substantially all
of the hydroxyl groups of the cellulose have been esterified, so
that the hydroxyl functionality necessary for formation of the
linear block copolymers preferentially appears only on the ends of
the polymer chains.
[0010] U.S. Pat. No. 3,391,135 discloses a process in which
hydrogen halides are used to reduce the molecular weight of
cellulose derivatives. The examples describe methylcellulose powder
and methyl-hydroxypropyl cellulose reacted with hydrogen chloride
to reduce the molecular weight, as evidenced by a reduction in
viscosity.
[0011] U.S. Pat. No. 3,518,249 describes oligosaccharide
tripropionates, having an average degree of polymerization of from
about 4 to about 20 and low levels of hydroxyl, that are useful as
plasticizers and as control agents for the manufacture of foamed
plastics. The oligosaccharide tripropionates are prepared by
degrading a cellulose propionate in the presence of an acid
catalyst. The patentees acknowledge that it has been an object in
the art to provide methods of preventing the degradation of
cellulose esters into low-viscosity oligosaccharide esters.
[0012] U.S. Pat. No. 4,532,177 describes base coat compositions
that include a film-forming resin component, selected from alkyd,
polyester, acrylic and polyurethane resins, from 1.0 to 15.0% by
weight pigment, and from 2.0% to 50.0% by weight of a cellulose
ester material. The '177 patent suggests a solution viscosity for
the cellulose ester material from 0.05-0.005 seconds, an acetyl
content from 10.0-15.0% by weight, a propionyl content from
0.1-0.8% by weight, a butyryl content from 36.0-40.0% by weight,
and a free-hydroxyl content of from 1.0-2.0% by weight. However,
the examples of the '177 patent use a cellulose ester having a
solution viscosity of 0.01, which is approximately equivalent to an
inherent viscosity (IV) for such an ester of from about 0.25 to
about 0.30 dL/g, as measured in a 60/40 (wt./wt.) solution of
phenol/tetrachloroethane (PM95) at 25.degree. C. We have found that
solution viscosities less than about 0.01 correlate poorly with IV
values and GPC molecular weight values, although there is a strong
correlation between IV and GPC molecular weights.
[0013] WO 91/16356 describes a process for the preparation of low
molecular weight, high-hydroxyl cellulose esters by treating a
cellulose polymer with trifluoroacetic acid, a mineral acid, and an
acyl or aryl anhydride in an appropriate carboxylic solvent,
followed by optional in situ hydrolysis. The cellulose esters
obtained according to the disclosure are said to have a number
average molecular weight (M.sub.n) ranging from about
0.01.times.10.sup.5 (about 1,000) to about 1.0.times.10.sup.5
(about 100,000), and an IV (inherent viscosity) from about 0.2 to
about 0.6, as measured at a temperature of 25.degree. C. for a 0.25
gram sample in 100 ml of a 60/40 by weight solution of
phenol/tetrachloroethane.
[0014] Japanese Kokai Patent Publication No. 51-119089 describes a
process for the preparation of a low molecular weight cellulose
mixed organic acid ester that involves heating cellulose acetate
with a saturated or unsaturated organic acid of 3 or more carbon
atoms (propionyl or higher), in the presence of an acid catalyst,
with removal of the resulting acetic acid from the reaction
mixture, to obtain a lower molecular weight cellulose mixed organic
acid ester. The starting material for this process is cellulose
acetate.
[0015] Another patent document naming the same inventors, Japanese
Kokai Patent Publication No. 51-119088, discloses a method for the
manufacture of a low molecular weight cellulose organic acid ester
that includes heating cellulose acetate with a saturated or
unsaturated organic acid at a temperature above 30.degree. C. in
the presence of a cation exchange resin, the resulting ester having
a lower molecular weight than the starting material. The starting
material for the disclosed process is cellulose acetate.
[0016] Both of these references teach low molecular weight mixed
cellulose esters. The process uses cellulose acetate as starting
material, and performs a transesterification while hydrolyzing the
cellulose backbone, the amount of higher mixed ester introduced
being relatively low.
[0017] U.S. Pat. No. 6,303,670 discloses an ultraviolet-curable
cellulosic coating composition comprising a cellulose acetate, a
diepoxy compound, and a photo cationic polymerization catalyst. The
cellulose acetate useful in these compositions is a low molecular
weight cellulose acetate, having a number-average molecular weight
of from 1,500 to 5,000, and is prepared from cellulose triacetate
by hydrolysis. According to this disclosure, the degree of
substitution of hydroxyl groups must be from 1 to 3, since hydroxyl
values of less than 1 are said to result in insufficient
crosslinking in the final coating composition.
[0018] Although efforts have been made to prepare oligosaccharides
via stepwise addition of anhydroglucose units, these methods are
not believed to result in cellulose derivatives that are suitable
for coating applications. Further, the costs of such processes
would be significant. See, for example, Nishimura, T.; Nakatsubo,
F. "Chemical Synthesis of Cellulose Derivatives by a Convergent
Synthetic Method and Several of Their Properties," Cellulose, 1997,
4, 109. See also Kawada, T.; Nakatsubo, F.; Umezawa, T.; Murakami,
K.; Sakuno, T. "Synthetic Studies of Cellulose XII: First Chemical
Synthesis of Cellooctaose Acetate," Mokuzai Gakkaishi 1994, 40(7),
738.
[0019] The present applicants have unexpectedly discovered that
relatively low molecular weight cellulose mixed esters, which were
thought to lack the properties necessary to provide the performance
characteristics of conventional molecular weight esters, can be
incorporated into coating compositions, without an undue increase
in viscosity, and without the high levels of solvent heretofore
necessary in the preparation of high solids coatings containing
cellulose esters. Also surprisingly, the properties of the
resulting coatings, when the coating compositions are applied and
cured, are comparable in most respects to those made using
conventional molecular weight esters.
[0020] Various esters according to the invention exhibit improved
solubilities in a variety of organic solvents, compatibility with
various co-resins, and suitable melt stability after prolonged
exposure to melt temperatures. Further advantages of the inventive
esters are set forth in the following.
SUMMARY OF THE INVENTION
[0021] The cellulose mixed esters according to the present
invention are low in molecular weight, have a high maximum degree
of substitution (are highly substitutable), and provide high
solids, low viscosity coating compositions, with none of the
drawbacks typically associated with low molecular weight cellulose
esters, such as formation of brittle films. When used as coating
additives in combination with one or more resins, the inventive
esters do not themselves unduly increase the viscosity of the
compositions, providing the advantages of conventional cellulose
esters without the drawbacks typically associated with their use,
such as an undesirable increase in organic solvent levels to
maintain the desired viscosity.
[0022] These new cellulose mixed esters have a high maximum degree
of substitution (DS) per anhydroglucose unit on the cellulose
backbone in the fully esterified or partially hydrolyzed form, and
generally have a DS for hydroxyl groups of less than about 0.70
(<0.70 DS hydroxyl). The maximum degree of substitution per
anhydroglucose unit for the cellulose esters of this invention is
from about 3.08 to about 3.50. These new mixed esters are soluble
in a wide range of organic solvents, allowing coatings formulators
a wide latitude of solvent choice. They have a minimal impact on
both the solution and spray viscosities of high solids coatings.
These materials exhibit superior compatibility when blended with
other coating resins, thereby yielding clear films with a wider
range of coatings resins than do conventional cellulose esters.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a graph plotting log viscosity as a function of
concentration for solutions of cellulose esters according to the
invention and conventional cellulose esters.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention may be understood more readily by
reference to the following detailed description of the invention,
and to the Examples included therein.
[0025] Before the present compositions of matter and methods are
disclosed and described, it is to be understood that this invention
is not limited to specific synthetic methods or to particular
formulations, unless otherwise indicated, and, as such, may vary
from the disclosure. It is also to be understood that the
terminology used is for the purpose of describing particular
embodiments only, and is not intended to limit the scope of the
invention.
[0026] The singular forms "a," "an," and "the" include plural
referents, unless the context clearly dictates otherwise.
[0027] Optional or optionally means that the subsequently described
event or circumstances may or may not occur. The description
includes instances where the event or circumstance occurs, and
instances where it does not occur.
[0028] Ranges may be expressed herein as from about one particular
value, and/or to about another particular value. When such a range
is expressed, it is to be understood that another embodiment is
from the one particular value and/or to the other particular
value.
[0029] Throughout this application, where patents or publications
are referenced, the disclosures of these references in their
entireties are intended to be incorporated by reference into this
application, in order to more fully describe the state of the art
to which the invention pertains.
[0030] As used throughout the disclosure, CAB means a cellulose
acetate butyrate; CAP means a cellulose acetate propionate; CA
means a cellulose acetate; CMCAB means a carboxymethylcellulose
acetate butyrate; CMCAP means a carboxymethylcellulose acetate
propionate; CMCA means a carboxymethylcellulose acetate; and HS-CAB
means an inventive high solids cellulose acetate butyrate according
to the invention, having a high maximum degree of substitution, a
low degree of polymerization, a low intrinsic viscosity (IV), and a
low molecular weight.
[0031] Unless indicated otherwise, HS-CAB-55 refers to an inventive
high solids cellulose acetate butyrate with a high maximum degree
of substitution, a low degree of polymerization, a low IV, a low
molecular weight, and a high butyryl content (high-butyryl, or from
about 52 to about 55 wt. %), prepared along the lines of Example 3,
unless noted otherwise; HS-CAB-46 refers to an inventive high
solids cellulose acetate butyrate with a high maximum degree of
substitution, a low degree of polymerization, a low IV, a low
molecular weight, and a medium to high butyryl content (high
mid-butyryl, or from about 43 to about 51 wt. %), prepared along
the lines of Examples 21-22 unless noted otherwise; HS-CAB-38
refers to an inventive high solids cellulose acetate butyrate with
a high maximum degree of substitution, a low degree of
polymerization, a low IV, a low molecular weight, and a medium
butyryl content (mid-butyryl, or from about 35 to about 42 wt. %),
prepared along the lines of Example 1, unless noted otherwise;
HS-CAB-36 refers to an inventive high solids cellulose acetate
butyrate with a high maximum degree of substitution, a low degree
of polymerization, a low IV, a low molecular weight, and a low
medium butyryl content (low mid-butyryl, or from about 30 to about
38 wt. %), prepared along the lines of Example 2, unless noted
otherwise; HS-CAB-17 refers to an inventive cellulose acetate
butyrate with a high maximum degree of substitution, a low degree
of polymerization, a low IV, a low molecular weight, and a low
butyryl content (low-butyryl, or from about 17 to about 24),
prepared along the lines of Examples 9-13, unless noted otherwise;
HS-CAB-20 likewise refers to an inventive cellulose acetate
butyrate with a high maximum degree of substitution, a low degree
of polymerization, a low IV, a low molecular weight, and a low
butyryl content (low-butyryl, or from about 17 to about 24),
prepared along the lines of Examples 9-13, unless noted otherwise,
and considered equivalent to an HS-CAB-17, as used throughout this
application; HS-CAP means an inventive high solids, cellulose
acetate propionate with a high maximum degree of substitution, a
low degree of polymerization, a low IV, and a low molecular weight;
and HS-CAP-54 means an inventive high solids, cellulose acetate
propionate with a high maximum degree of substitution, a low degree
of polymerization, a low IV, and a low molecular weight, and a high
propionyl content (high-propionyl, or from about 49 to about 56 wt.
%), prepared along the lines of Example 52, unless noted
otherwise.
[0032] In one embodiment, the invention relates to cellulose mixed
esters having a total degree of substitution per anhydroglucose
unit of from about 3.08 to about 3.50, and having the following
substitutions: a degree of substitution per anhydroglucose unit of
hydroxyl of no more than about 0.70; a degree of substitution per
anhydroglucose unit of C.sub.3-C.sub.4 esters from about 0.80 to
about 1.40, and a degree of substitution per anhydroglucose unit of
acetyl of from about 1.20 to about 2.34. According to this
embodiment, the inventive mixed esters exhibit an inherent
viscosity from about 0.05 to about 0.15 dL/g, as measured in a
60/40 (wt./wt.) solution of phenol/tetrachloroethane at 25.degree.
C.; a number average molecular weight (M.sub.n) of from about 1,000
to about 5,600; a weight average molecular weight (M.sub.w) of from
about 1,500 to about 10,000; and a polydispersity of from about 1.2
to about 3.5. In various embodiments, the ester may comprise
butyryl, or propionyl, or mixtures of the two.
[0033] In various alternative aspects, the degree of substitution
per anhydroglucose unit of hydroxyl may be from about 0.05 to about
0.70; the inherent viscosity may be from about 0.05 to about 0.12
dL/g, as measured in a 60/40 (wt./wt.) solution of
phenol/tetrachloroethane at 25.degree. C.; or the number average
molecular weight (M.sub.n) may be from about 1,500 to about 5,000.
In certain embodiments, a preferred polydispersity may be from 1.2
to 2.5; a preferred inherent viscosity from 0.07 to 0.11 dL/g; or a
preferred number average molecular weight (M.sub.n) from about
1,000 to about 4,000. In certain other embodiments, a preferred
inherent viscosity may be from about 0.07 to about 0.11 dL/g; or a
preferred number average molecular weight (M.sub.n) from about
1,000 to 4,000.
[0034] In a further embodiment, the invention relates to cellulose
mixed esters having a total degree of substitution per
anhydroglucose unit of from about 3.08 to about 3.50, and having
the following substitutions: a degree of substitution per
anhydroglucose unit of hydroxyl of no more than about 0.70; a
degree of substitution per anhydroglucose unit of C.sub.3-C.sub.4
esters from about 1.40 to about 2.45, and a degree of substitution
per anhydroglucose unit of acetyl of from 0.20 to about 0.80.
According to this embodiment, the inventive mixed esters exhibit an
inherent viscosity of from about 0.05 to about 0.15 dL/g, as
measured in a 60/40 (wt./wt.) solution of phenol/tetrachloroethane
at 25.degree. C.; a number average molecular weight (M.sub.n) of
from about 1,000 to about 5,600; a weight average molecular weight
(M.sub.w) of from about 1,500 to about 10,000; and a polydispersity
of from about 1.2 to about 3.5. In various embodiments, the ester
may comprise butyryl, or propionyl, or mixtures of the two.
[0035] In various alternative embodiments, the degree of
substitution per anhydroglucose unit of hydroxyl may be from about
0.05 to about 0.70; the inherent viscosity may be from about 0.05
to about 0.12 dL/g, as measured in a 60/40 (wt./wt.) solution of
phenol/tetrachloroethane at 25.degree. C.; or the number average
molecular weight (M.sub.n) may be from about 1,500 to about 5,000.
In certain embodiments, a preferred polydispersity may be from 1.2
to 2.5; a preferred inherent viscosity from 0.07 to 0.11 dL/g; or a
preferred number average molecular weight (M.sub.n) from about
1,000 to about 4,000. In certain other embodiments, a preferred
inherent viscosity may be from about 0.07 to about 0.11 dL/g; and a
preferred number average molecular weight (M.sub.n) from about
1,000 to 4,000.
[0036] In yet another embodiment, the invention relates to
cellulose mixed esters having a total degree of substitution per
anhydroglucose unit of from about 3.08 to about 3.50, and having
the following substitutions: a degree of substitution per
anhydroglucose unit of hydroxyl of no more than about 0.70; a
degree of substitution per anhydroglucose unit of C.sub.3-C.sub.4
esters from about 2.11 to about 2.91, and a degree of substitution
per anhydroglucose unit of acetyl of from 0.10 to about 0.50.
According to this embodiment, the inventive mixed esters may
exhibit an inherent viscosity of from about 0.05 to about 0.15
dL/g, as measured in a 60/40 (wt./wt.) solution of
phenol/tetrachloroethane at 25.degree. C.; a number average
molecular weight (M.sub.n) of from about 1,000 to about 5,600; a
weight average molecular weight (M.sub.w) of from about 1,500 to
about 10,000; and a polydispersity of from about 1.2 to about 3.5.
In various embodiments, the ester may comprise butyryl, or
propionyl, or mixtures of the two.
[0037] In various alternative embodiments, the degree of
substitution per anhydroglucose unit of hydroxyl may be from about
0.05 to about 0.70; the inherent viscosity may be from about 0.05
to about 0.12 dL/g, as measured in a 60/40 (wt./wt.) solution of
phenol/tetrachloroethane at 25.degree. C.; or the number average
molecular weight (M.sub.n) may be from about 1,500 to about 5,000.
In certain embodiments, a preferred polydispersity may be from 1.2
to 2.5; a preferred inherent viscosity from 0.07 to 0.11 dL/g; and
a preferred number average molecular weight (M.sub.n) from about
1,000 to about 4,000. In certain other embodiments, a preferred
inherent viscosity may be from about 0.07 to about 0.11 dL/g; and a
preferred number average molecular weight (M.sub.n) from about
1,000 to 4,000.
[0038] The present invention thus provides certain mixed esters of
cellulose, which are useful, for example, as binder components and
additives in coatings compositions. The inventive esters may have
an inherent viscosity of from about 0.05 to about 0.15 dL/g, or
from about 0.07 to about 0.11 dL/g, as measured in a 60/40
(wt./wt.) solution of phenol/tetrachloroethane at 25.degree. C. (as
further defined below), and a maximum degree of substitution per
anhydroglucose unit from about 3.08 to about 3.50, and a degree of
substitution per anhydroglucose unit of organic esters, for example
those having from 1 to 12 carbon atoms, preferably C.sub.2-C.sub.4
alkyl esters, and more preferably saturated C.sub.2-C.sub.4 alkyl
esters, of about 2.38 to about 3.50. As is described below, these
resins are especially useful in coating and ink formulations. They
are soluble in a wide range of solvents and solvent blends, as
demonstrated in the examples of this application, making them
particularly suited for custom coating formulations. The cellulose
esters may be alkyl cellulose esters, such as methylcellulose, or
hydroxyalkyl cellulose esters, such as methyl-hydroxypropyl
cellulose esters. However, in some embodiments, the cellulose
esters are esters that are not otherwise modified, i.e. the
cellulose is modified only by the addition of organic ester
functionality, not ether functionality or carboxyl functionality
obtained via oxidation chemistry. Certain particular novel esters
are preferred and further provided as additional embodiments of
this invention.
[0039] In yet another embodiment, there is provided a cellulose
mixed ester, having a maximum degree of substitution of from about
3.08 to about 3.50, a degree of substitution per anhydroglucose
unit of hydroxyl from about 0.01 up to about 0.70, a degree of
substitution per anhydroglucose unit of C.sub.3-C.sub.4 esters of
about 0.8 to about 3.50, a degree of substitution per
anhydroglucose unit of acetyl from about 0.05 to about 2.00, and
having an inherent viscosity of about 0.05 to about 0.15 dL/g, as
measured in a 60/40 (wt./wt.) solution of phenol/tetrachloroethane
at 25.degree. C. In various alternative embodiments, the inherent
viscosity may be from about 0.07 to about 0.11 dL/g, the degree of
substitution per anhydroglucose unit of hydroxyl from 0.10 to 0.70,
the degree of substitution per anhydroglucose unit of
C.sub.3-C.sub.4 esters from 1.10 to 3.25, or the degree of
substitution per anhydroglucose unit of acetyl from 0. 05 to 0.90.
Various esters according to this embodiment exhibit solubility in a
wide range of solvents and solvent blends.
[0040] In another embodiment, there is provided a cellulose mixed
ester, having a maximum degree of substitution of from about 3.08
to about 3.50, a degree of substitution per anhydroglucose unit of
hydroxyl from about 0.01 up to about 0.70, a degree of substitution
per anhydroglucose unit of C.sub.3-C.sub.4 esters of about 0.8 to
about 3.50, a degree of substitution per anhydroglucose unit of
acetyl from about 0.05 to about 2.00, and having an inherent
viscosity of about 0.05 to about 0.15 dL/g, as measured in a 60/40
(wt./wt.) solution of phenol/tetrachloroethane at 25.degree. C. In
various alternative embodiments, the inherent viscosity may be from
about 0.07 to about 0.11 dL/g, the degree of substitution per
anhydroglucose unit of hydroxyl about 0, the degree of substitution
per anhydroglucose unit of C.sub.3-C.sub.4 esters from 2.60 to
3.40, or the degree of substitution per anhydroglucose unit of
acetyl from 0.10 to 0.90. Various esters according to these
embodiments exhibit solubility in a wide range of solvents and
solvent blends.
[0041] In another embodiment of the present invention, there is
provided a cellulose acetate butyrate having a maximum degree of
substitution of from about 3.08 to about 3.50, and a degree of
substitution per anhydroglucose unit of hydroxyl from about 0.01 to
about 0.70, and a degree of substitution per anhydroglucose unit of
butyryl of about 0.80 to about 3.44, and a degree of substitution
per anhydroglucose unit of acetyl of about 0.05 to about 2.00, and
having an inherent viscosity of 0.05 to 0.15 dL/g, as measured in a
60/40 (wt./wt.) solution of phenol/tetrachloroethane at 25.degree.
C. In various alternative embodiments, the inherent viscosity may
be from 0.07 to 0.11 dL/g, the degree of substitution per
anhydroglucose unit of hydroxyl from 0.10 to 0.70, butyryl from
1.10 to 3.25, or acetyl from 0.10 to 0.90. Various esters according
to this embodiment exhibit solubility in a wide range of solvents
and solvent blends.
[0042] As a further embodiment, there is provided a cellulose
acetate propionate having a degree of substitution per
anhydroglucose unit of hydroxyl from about 0.01 to about 0.70, and
a degree of substitution per anhydroglucose unit of propionyl of
about 0.80 to about 3.44 and a degree of substitution per
anhydroglucose unit of acetyl of from about 0.05 to about 2.00, and
having an inherent viscosity of about 0.05 to about 0.15 dL/g, as
measured in a 60/40 (wt./wt.) solution of phenol/tetrachloroethane
at 25.degree. C. In various alternative embodiments, the inherent
viscosity may be from 0.07 to 0.11 dL/g, the degree of substitution
per anhydroglucose unit of hydroxyl from 0.10 to 0.70, the degree
of substitution per anhydroglucose unit of propionyl from 1.10 to
3.25, or the degree of substitution per anhydroglucose unit of
acetyl of from 0.10 to 0.90. Various esters according to this
embodiment exhibit solubility in a wide range of solvents and
solvent blends.
[0043] Different grades and sources of cellulose are available and
are useful according to the invention, and can be selected from
cotton linters, softwood pulp, hardwood pulp, corn fiber and other
agricultural sources, and bacterial cellulose, among others. The
source of cellulose used to prepare the cellulose esters of the
invention is important in providing a product having suitable
properties. It is generally preferred that a dissolving-grade
cellulose be used as starting material for preparing the cellulose
esters of this invention. It is more preferred that the
dissolving-grade cellulose have an .alpha.-cellulose content of
greater than 94%. Those skilled in the art will also recognize that
the use of cellulose from different sources may require
modifications to the reaction conditions (e.g. temperature,
catalyst loading, time) in order to account for any differences in
the reactivity of the cellulose.
[0044] In certain embodiments, it is preferred that the source of
cellulose be a natural cellulose as just described, and that the
source of cellulose not be a modified cellulose such as a cellulose
ether, e.g. an alkyl cellulose. Similarly, in certain embodiments,
it is preferred that the cellulose starting material not be a
carboxyalkylcellulose, such as carboxymethylcellulose, or any
cellulose derivative having acid functionality. These cellulose
derivatives are more expensive than the naturally-derived cellulose
just described, and in many cases result in esters that are less
suitable than the inventive esters in coating formulations,
especially those containing appreciable amounts of organic
solvents. It also follows that certain of the inventive esters
according to the invention have an acid value no greater than about
5, or no greater than about 1. Suitable cellulose esters containing
carboxyl functionality are being separately pursued in a copending
application filed herewith.
[0045] The cellulose esters of the invention may be prepared by a
multi-step process. In this process, cellulose is water-activated,
followed by water displacement via solvent exchange with an
alkanoic acid such as acetic acid, followed by treatment with a
higher alkanoic acid (propionic acid or butyric acid) to give a
cellulose activate wet with the appropriate alkanoic acid. Next,
the cellulose activate is treated with the desired anhydride, in
the presence of a strong acid catalyst such as sulfuric acid, to
give essentially a fully-substituted cellulose ester having a lower
molecular weight than conventional esters. A solution consisting of
water and an alkanoic acid is added slowly to the anhydrous "dope"
solution so as to allow removal of combined sulfur from the
cellulose backbone. The final addition allows a slow transition
through the hydrous point to give a period of low water
concentration and high temperature (as a result of the exotherm
from water reacting with excess anhydride) in the reaction medium.
This is important for hydrolysis of combined sulfur from the
cellulose backbone. This product is then hydrolyzed using sulfuric
acid to provide a partially substituted cellulose ester. Hydrolysis
is important to provide gel-free solutions in organic solvents, and
to provide better compatibility with other resins in coatings
applications. The hydroxyl groups exposed during hydrolysis are
also important crosslinking sites in many coatings
applications.
[0046] Next, the sulfuric acid is neutralized after the
esterification or hydrolysis reactions are complete by addition of
a stoichiometric amount of an alkali or alkaline earth metal
alkanoate, for example, magnesium acetate, dissolved in water and
an alkanoic acid such as acetic acid. Neutralization of the strong
acid catalyst is important for optimal thermal and hydrolytic
stability of the final product.
[0047] Finally, either the fully substituted or partially
hydrolyzed forms of cellulose ester are isolated by diluting the
final neutralized "dope" with an equal volume of acetic acid
followed by precipitation of the diluted "dope" into a volume of
water about 20 to 30 times its weight, to give a particle that can
be easily washed with deionized water to efficiently remove
residual organic acids and inorganic salts. In many cases, a fairly
sticky precipitate is initially formed. The precipitate can be
hardened by exchanging the precipitation liquid for fresh water and
allowing the precipitate to stand. The hardened precipitate can
then be easily washed and ground up as necessary.
[0048] The key descriptors of the composition of a cellulose ester
are the level of substitution of the various ester groups (i.e.
degree of substitution or wt. % are commonly used and are discussed
in detail in other parts of this application), the level of
hydroxyl groups, and the size of the polymer backbone, which can be
inferred from IV, viscosity, and GPC data. The key factors that
influence the resulting composition of the inventive cellulose
mixed esters thus produced are: acetic anhydride level, acetic acid
level, butyric (or propionic) anhydride level, butyric (or
propionic) acid level, water level, cellulose level, catalyst type,
catalyst level, time, and temperature. One skilled in the art will
appreciate that higher catalyst loadings, higher temperatures,
and/or longer reaction times during esterification are used to
produce the inventive cellulose esters, having lower molecular
weights than conventional esters.
[0049] Thus, as a further aspect of the invention, the cellulose
esters of the invention may be prepared by a multi-step process. In
the process according to the invention, cellulose is
water-activated, followed by water displacement via solvent
exchange with an alkanoic acid such as acetic acid, followed by
solvent exchange with a higher alkanoic acid (e.g. propionic acid
or butyric acid) to give a cellulose-activate wet with the
appropriate alkanoic acid (e.g. propionic or butyric acid). In this
regard, we have found that it is important that the starting
cellulose has a 94 to 99% alpha content, preferably about 95 to 98%
alpha cellulose content. The high alpha content is important for
the quality of the final products prepared therefrom. We have found
that low alpha cellulose pulps lead to poor solubility in organic
solvents and consequently to poor formulations.
[0050] Next, the activated cellulose is reacted with the desired
anhydride in the presence of a strong acid catalyst such as
sulfuric acid to give a fully substituted cellulose ester with a
lower molecular weight than conventional esters. A solution
containing water and an alkanoic acid or mixture of alkanoic acids
is added slowly to the anhydrous "dope" solution so as to allow
removal of combined sulfur from the cellulose backbone. The final
addition allows a slow transition through the hydrous point to give
a period of low water concentration and high temperature (as a
result of the exotherm from water reacting with excess anhydride)
in the reaction medium. This is important for hydrolysis of
combined sulfur from the cellulose backbone. This product is then
hydrolyzed using sulfuric acid to provide a partially-substituted
cellulose ester. Hydrolysis is important to provide gel-free
solutions in organic solvents, and to provide better compatibility
with other resins in coatings applications.
[0051] Next, the sulfuric acid is neutralized after the
esterification or hydrolysis reactions are complete by addition of
a stoichiometric amount of an alkali or alkaline earth metal
alkanoate, for example magnesium acetate, dissolved in water and an
alkanoic acid such as acetic acid. Neutralization of the strong
acid catalyst is important for optimal thermal and hydrolytic
stability of the final product.
[0052] Finally, either the fully substituted or partially
hydrolyzed forms of cellulose ester are isolated by diluting the
final neutralized "dope" with an equal volume of acetic acid
followed by precipitation of the diluted "dope" into a volume of
water about 20 to 30 times its weight, to give a particle that can
be easily washed with deionized water to efficiently remove
residual organic acids and inorganic salts. In many cases, a fairly
sticky precipitate is initially formed. The precipitate can be
hardened by exchanging the precipitation liquid for fresh water and
allowing the precipitate to stand. The hardened precipitate can
then be easily washed and ground up as necessary.
[0053] In light of the present disclosure, those skilled in the art
will readily appreciate that, of the process parameters just
described, higher catalyst loadings, higher temperatures, and/or
longer reaction times during esterification will be used to obtain
the inventive cellulose esters having lower molecular weights than
conventional cellulose esters, as further evidenced in the examples
of this disclosure.
[0054] The cellulose esters according to the invention have a
weight average molecular weight, M.sub.w, as measured by GPC, of
from about 1,500 to about 10,000; or from about 2,000 to about
8,500; a number average molecular weight, M.sub.n, as measured by
GPC, of from about 1,500 to about 6,000; and a polydispersity,
defined as M.sub.W/M.sub.n, from about 1.2 to about 7, or from
about 1.2 to about 3.5, or from about 1.2 to about 2.5.
[0055] The cellulose mixed esters according to the invention,
sometimes described herein as HS-CAB's, exhibit compatibility with
a wide variety of co-resins, compatibility being defined as the
ability of two or more resins, when mixed together, to form a
stable homogeneous mixture useful as a coating composition. For
example, an HS-CAB with approximately 38 wt. % butyryl (sometimes
described herein as an HS-CAB-38) exhibits compatibilities with
Eastman's Acrylamac 2328, Akzo Nobel's Microgel, Eastman's Duramac
2314, Bayer's Desmodur 3300, Rhodia's XIDT, and Bayer's Desmodur
IL, equal to or better than commercial higher-butyryl-content
samples such as CAB-551-0.01 (cellulose acetate butyrate containing
approximately 55 wt. % butyryl, available from Eastman Chemical
Company). In some instances, inventive cellulose mixed esters
having approximately 38 wt. % butyryl, or approximately 55 wt. %
butyryl, are compatible at a 1:1 ester to resin loading with
acrylic resins that are not compatible with many conventional
molecular weight cellulose esters. Such dramatic shifts in
compatibility allow formulators to use a mid-butyryl ester (about
38 wt. %) in applications that might otherwise require a higher
butyryl CAB for compatibility purposes.
[0056] An advantage to being able to use a mid-butyryl ester
instead of a high-butyryl ester is that when all properties aside
from butyryl level and acetyl level remain constant, i.e. hydroxyl
value and molecular weight, the mid-butyryl CAB has a higher
T.sub.g than its high-butyryl counterpart. Another advantage to
using a mid-butyryl ester over a high-butyryl ester is that
mid-butyryl commercial esters are often less soluble in particular
solvents and solvent blends than their high-butyryl counterparts.
This same trend is generally observed when comparing mid-butyryl
HS-CAB's with high-butyryl HS-CAB's of equivalent molecular weight
and hydroxyl content. Without being bound by theory, we believe
that the observed solubility differences between mid-butyryl and
high-butyryl esters is responsible in part for the improved
redissolve resistance seen with certain of the inventive esters
when a topcoat is applied to a basecoat. We believe that the
combination of improved compatibility along with improved, but also
differentiated, solubility will be a valuable asset to coatings
formulation chemists.
[0057] Thus, conventional cellulose esters with a higher butyryl
content tend to be more soluble and have a lower T.sub.g than their
counterparts having lower butyryl levels. One result of increased
solubility is that the redissolve resistance of the resulting
coating is negatively affected. One of the key advantages of a
conventional high butyryl cellulose ester such as CAB-551-0.01 is
its increased compatibility with many co-resins when compared with
a mid-butyryl ester such as CAB-381-0.1. Surprising, we have found
that inventive mid-butyryl esters (HS-CAB-38) according to the
invention have better compatibility with co-resins than a
conventional molecular weight high butyryl cellulose ester such as
a CAB-551-0.01, while exhibiting a similar solubility. As a result,
coatings formulators can use the inventive esters of the invention
in basecoat formulations that cannot tolerate the viscosity
increase imparted by the addition of conventional CAB's, while
providing the redissolve resistance typical of conventional esters
having a higher butyryl content.
[0058] As mentioned, the inventive mixed esters likewise
demonstrate better-than-expected redissolve resistance in certain
systems. This is surprising, since the inventive mixed esters have
a molecular weight lower than conventional cellulose mixed esters.
One would instead expect to see a decrease in redissolve resistance
with a lowering in molecular weight. As a result, coatings
formulators can use the inventive esters of the invention in
basecoat formulations that cannot tolerate the viscosity increase
imparted by the addition of conventional CAB's, while providing the
necessary redissolve resistance.
[0059] As is also evident from the examples, cellulose esters
according to the invention have excellent melt stability after
prolonged exposure to melt temperatures. When HS-CABs according to
the invention were used in preparing pigment grinds on a two-roll
mill, no discoloring was observed due to decomposition even after
prolonged exposure (at least 30 minutes) to melt temperatures of
about 100.degree. C. to about 120.degree. C. Melt stability is an
important property for cellulose esters used in plastic
applications, since yellowing, a common result of poor melt
stability, is often a detrimental characteristic of cellulosics
used in plastics applications.
[0060] Further, the inventive esters exhibit a better-defined
melting point, as further described herein, making them especially
suitable for uses where a well-defined melting point is necessary.
Not being bound by theory, we attribute this to a lower
polydispersity value than conventional esters.
[0061] Traditionally, cellulose esters are considered to have a
maximum degree of substitution of 3.0. A DS of 3.0 indicates that
there are 3.0 reactive hydroxyl groups in cellulose that can be
derivatized. Native cellulose is a large polysaccharide with a
degree of polymerization from 700-2,000, and thus the assumption
that the maximum DS is 3.0 is approximately correct. However, as
the degree of polymerization is lowered, the end groups of the
polysaccharide backbone become relatively more important. In the
esters according to the invention, this change in maximum DS
influences the performance of the esters, by changing the
solubility in certain solvents and the compatibility with certain
coatings resins.
[0062] Table 1 gives the DS.sub.Max at various degrees of
polymerization. Mathematically, a degree of polymerization of 401
is required in order to have a maximum DS of 3.00. As the table
indicates, the increase in DS.sub.Max that occurs with a decrease
in DP is slow, and for the most part, assuming a maximum DS of 3.00
is acceptable. However, once the DP is low enough, for example a DP
of 21, then it becomes appropriate to use a different maximum DS
for all calculations.
TABLE-US-00001 TABLE 1 Effect of DSMax on DP DP DS.sub.Max 1 5.00 2
4.00 3 3.67 4 3.50 5 3.40 6 3.33 7 3.29 8 3.25 9 3.22 10 3.20 11
3.18 12 3.17 13 3.15 14 3.14 15 3.13 16 3.13 17 3.12 18 3.11 19
3.11 20 3.10 21 3.10 22 3.09 23 3.09 24 3.08 25 3.08 50 3.04 75
3.03 100 3.02 134 3.01 401 3.00
[0063] The present invention thus provides a cellulose ester with a
high maximum degree of substitution and a low degree of
polymerization.
[0064] As already described, the inventive esters of the present
application, having a high maximum degree of substitution and a low
degree of polymerization, unexpectedly exhibit rheological
performance similar to conventional cellulose esters having a much
higher degree of polymerization. It is quite surprising that an
HS-CAB with such a low degree of polymerization would display such
rheological performance.
[0065] Without being bound by any theory, we believe that the
cellulose esters according to the invention exhibit a fairly random
substitution pattern of hydroxyl groups. We believe that this
random substitution pattern of hydroxyl groups is achieved by
performing the molecular weight reduction step prior to hydrolysis
of the ester groups. The low molecular weight cellulose ester
products of the prior art processes generally exhibit a non-random
substitution pattern, particularly at C-4 of the non-reducing
terminus and at C-1 (RT1) of the reducing terminus. The products of
the prior art generally have a hydroxyl group at C-4 and either a
hydroxyl or ester at C-1 (RT-1) depending on whether the process is
a hydrolysis or an acetolysis reaction.
[0066] The widely accepted mechanism presented in Scheme 1 may help
the reader to visualize the explanation above. The proposed
mechanism presented in Scheme 1 depicts the reaction of a
polysaccharide with a high degree of polymerization, the nature of
the groups at C4 and RT1 being influenced by the amount of cleavage
that occurs. The substitution at the two carbons of interest, C4
and RT1, increases to large levels as more and more glycosidic
bonds are cleaved. Scheme 1 shows only a single glycosidic bond
being cleaved and thus only one C4 and one RT1 site have the
substitution pattern displayed by products generated by the prior
art. As more and more sites are cleaved, the effect of the
substitution pattern at C4 and RT1 becomes more important.
[0067] Processes used to prepare the products of the present
invention result in a fully-esterified cellulose ester having
approximately the desired degree of polymerization while the
reaction mixture is still anhydrous (i.e. before hydrolysis). As a
result, the hydrolysis of esters during the preparation of the
products of this invention is believed to produce essentially a
random distribution of hydroxyl groups throughout the entire
cellulosic backbone. This belief is based, in part, on the unique
solubility profiles exhibited by the esters according to the
invention. Those skilled in the art will recognize that under
kinetically controlled conditions, hydrolysis will occur
preferentially at certain sites (e.g. C6>>C2>C3). The
hydrolysis process practiced in this invention is performed under
thermodynamic control (i.e. under equilibrium conditions), which is
believed to result in a more random distribution of hydroxyl
functionality throughout the cellulosic backbone.
##STR00001##
[0068] .sup.13C-NMR studies suggest that the inventive esters
(HS-CAB's) have a different substitution pattern than those made by
processes in which molecular weight is reduced during hydrolysis.
The chemical structure below highlights the areas where differences
in the substitution patterns are believed to occur.
##STR00002##
[0069] Cellulose mixed esters of the invention have utility in
pigment dispersions by blending the cellulose ester and a pigment
with heat and/or shear to disperse the pigment. In this manner,
pigments can be easily dispersed in coating formulations and
plastics, thereby providing high coloring power and good
transparency while using a minimal amount of pigment. Such pigment
dispersions can be improved by the use of the cellulose esters of
the present invention in place of conventional cellulose esters. As
with conventional cellulose esters, the cellulose mixed esters of
the present invention impart markedly improved wetting properties
to the pigment dispersion. Mixtures of C.sub.2-C.sub.4 esters of
cellulose and pigments at pigment: ester weight ratios of about
20:80 to 50:50 may be prepared. These dispersions can be prepared
on a two-roll mill or in a ball mill, Kady mill, sand mill, or the
like. The high DS.sub.Max, low DP cellulose esters of this
invention have an advantage over conventional cellulose esters in
that they have less of an impact on the viscosity, and thus allow
formulations with a higher binder (resin) loading to be used.
[0070] Thus, the present invention provides a pigment dispersion
comprising about 20 to 77 weight percent of a pigment and
correspondingly about 33 to 80 percent by weight of a
C.sub.2-C.sub.4 ester of cellulose having an inherent viscosity of
about 0.05 to 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution
of phenol/tetrachloroethane at 25.degree. C., and a degree of
substitution per anhydroglucose unit of C.sub.2-C.sub.4 esters of
about 0.8 to about 3.5.
[0071] The esters of the invention are easily formulated into
either lacquer or enamel type coatings where they are used as
rheology modifiers and/or binder components providing improved
aluminum flake orientation and improved hardness. They can provide
a water-clear, high gloss, protective coating for a variety of
substrates, especially metal and wood.
[0072] An additional advantage, when used for example to prepare
pigments for use in plastics or coatings, relates to an increase in
melt stability exhibited by the esters of the invention. The
inventive HS-CABs have a sharper melting range than commercial
CAB's, possibly due to the tighter polydispersity of HS-CAB's
versus conventional CAB's. HS-CAB's can be blended with a pigment
to produce a pigment dispersion. The pigment dispersions can be
prepared by a number of routes including a slurry method and by
extrusion. The improved melt stability is advantageous in extruder
applications, since yellowing of the cellulosic is reduced or
eliminated.
[0073] Cellulose esters of this invention, especially high
DS.sub.Max, low DP cellulose acetate butyrate and high DS.sub.Max,
low DP cellulose acetate propionate, as described above, exhibit
improved solubility and compatibility (i.e., film clarity)
characteristics over many conventional cellulose esters (cellulose
acetate, cellulose propionate, cellulose butyrate, cellulose
acetate propionate, or cellulose acetate butyrate).
[0074] For example, conventional mid-butyryl cellulose esters such
as CAB-381-0.1 (available from Eastman Chemical Company, Kingsport,
Tenn.), as evidenced for example in Comparative Example 31 and
Example 49, are not readily soluble in Eastman C-11 ketone (a
mixture of saturated and unsaturated, linear and cyclic ketones),
Eastman DIBK (diisobutyl ketone), PP (propylene glycol monopropyl
ether), Eastman EP solvent (ethylene glycol monopropyl ether),
Eastman EB solvent (ethylene glycol monobutyl ether), methanol,
Tecsol C solvent, 95% (ethanol with methanol, methyl isobutyl
ketone, and ethyl acetate as denaturants with 5% water), toluene,
or a 90/10 isopropyl alcohol/water blend. In contrast, certain
inventive esters such as certain of the HS-CAB-38s (as exemplified
in Example 28 and Example 49) of the invention are soluble in each
of the solvents or solvent systems described above. By the term
"soluble," as used throughout the specification, we mean that a
clear solution is obtained when a 10% (wt/wt) mixture of the
cellulose ester in the desired solvent is prepared, unless stated
otherwise.
[0075] As another example, conventional high-butyryl cellulose
esters such as CAB-551-0.01 (available from Eastman Chemical
Company), as evidenced in Comparative Example 32 and Example 49,
are not readily soluble in methanol, Tecsol C solvent, 95%, toluene
(the ester gels), or a 90/10 isopropyl alcohol/water blend. In
contrast, certain inventive esters, such as certain of the
high-butyryl cellulose esters (HS-CAB-55's), as evidenced in
Example 29 and some of the inventive esters of Example 49, are
soluble in each of the solvents or solvent systems described
above.
[0076] Similarly, conventional low-butyryl cellulose esters such as
CAB-171-15S (available from Eastman Chemical Company), as evidenced
in Comparative Example 33, are not readily soluble in Eastman PM
solvent (propylene glycol monomethyl ether), and only partially
soluble in Eastman PM acetate (propylene glycol methyl acetate) and
Eastman DM solvent (diethylene glycol methyl ether). In contrast,
certain inventive esters, such as certain of the low-butyryl
cellulose esters HS-CAB-17s and HS-CAB-20s, as evidenced in Example
30 and Example 49, are soluble in each of these solvents or solvent
systems.
[0077] It is important to recognize that, as with conventional
molecular weight esters, there are important factors other than
butyryl content that influence the solubility of HS-CAB's, such as
acetyl/butyryl ratio and hydroxyl content. This can be seen
especially in Example 49, in which varying levels of hydroxyl and
acetate affect the solubility of esters having similar butyryl
content. These ester substitutions may be varied by those skilled
in the art, in light of the present disclosure, to obtain the
desired solubility in a given solvent, and the desired
compatibility with a given resin. We note that the inventive esters
evidence increased solubility, when compared with those esters
having conventional molecular weight, at similar hydroxyl and
acetate levels.
[0078] As demonstrated in the examples, the inventive esters are
soluble in most classes of typical coating solvents, including
ketones, esters, alcohols, glycol ethers, and glycol ether esters,
while tolerating dilution with water or aromatic hydrocarbons.
[0079] Examples of typical solvents in which the inventive esters
exhibit solubility include acetone, methyl ethyl ketone, methyl
isobutyl ketone, methyl amyl ketone, methyl propyl ketone,
2-propoxyethanol, 2-butoxyethanol, ethyl 3-ethoxypropionate,
ethanol, methanol isopropyl alcohol, diacetone alcohol, ethylene
glycol monobutyl ether acetate, ethyl acetate, propyl acetate,
isopropyl acetate, butyl acetate, isobutyl acetate diethylene
glycol ethyl ether, Eastman PM acetate (propylene glycol methyl
acetate), Eastman EB acetate (ethylene glycol butyl acetate),
Eastman PM Solvent (propylene glycol monomethyl ether), Eastman DM
Solvent (diethylene glycol methyl ether), Eastman PB Solvent
(propylene glycol monobutyl ether, Eastman DE Solvent (diethylene
glycol ethyl ether), Eastman PP Solvent (propylene glycol
monopropyl ether), Eastman EP Solvent (ethylene glycol monopropyl
ether), Eastman EB Solvent (ethylene glycol monobutyl ether),
Eastman 95% Tecsol C (ethanol with methanol, MIBK and ethyl acetate
as denaturants with 5% water), N-methyl pyrrolidone, Eastman EEP
Solvent (ethyl 3-ethoxypropionate), and other volatile inert
solvents typically used in coating compositions. For example,
organic solutions of the esters of this invention can be prepared
by adding 1 to 1000 parts of solvent per part of ester; 1.5 to 9
parts of solvent per part of ester is preferred.
[0080] The esters of the present invention exhibit viscosities in
organic solutions that in many cases differ substantially from
those of conventional molecular weight esters. Thus, in Example 34
of the present disclosure, the viscosities of an HS-CAB-38 (Sample
4, Table 4) and an HS-CAB-55 (Sample 5, Table 4) are compared to
the lowest viscosity commercial cellulose esters, CAB-381-0.1 and
CAB-551-0.01, of comparable butyryl content, using as solvent a
90/10 by weight mixture of n-butyl acetate/xylene. FIG. 1 shows a
representative comparison of the relative viscosity at each
measured concentration. The log viscosities vs. concentration plots
are parallel for each of the esters, indicating that each of the
esters has a similar exponential viscosity rise with concentration,
except that the lower the molecular weight of the ester, the higher
the concentration becomes to display the same behavior. Additional
Brookfield viscosity data are presented in Table 6A of Example 34.
Because the inventive esters exhibit a lower viscosity than
conventional esters at the same concentration, they allow coating
formulations having a higher ester content at the target
viscosity.
[0081] Thus, some conventional high-butyryl cellulose esters such
as CAB-551-0.01 (available from Eastman Chemical Company), as
evidenced in Table 6A of Example 34, exhibit a viscosity greater
than 10,000 centipoise (in a 90/10 by weight mixture of n-butyl
acetate/xylene) as a 50 wt. % solution. In contrast, certain
inventive esters having comparable butyryl content (HS-CAB-55)
exhibit viscosities in the same solution of less than 200
centipoise at a 50 wt. % solution.
[0082] Likewise, conventional mid-butyryl cellulose esters such as
CAB-381-0.1 (available from Eastman Chemical Company, Kingsport,
Tenn.), as evidenced in Example 34, exhibit a viscosity greater
than 500,000 centipoise (in a 90/10 by weight mixture of n-butyl
acetate/xylene) as a 50 wt. % solution. In contrast, certain
inventive esters having comparable butyryl content (HS-CAB-38)
exhibit viscosities in the same solution of less than 500
centipoise at a 50 wt. % solution.
[0083] Further, certain inventive low-butyryl cellulose esters such
as HS-CAB-17, as can be seen in Table 6A of Example 34, exhibit
viscosities no greater than 6,000 centipoise, and others no greater
than 3,000 centipose, as a 50 wt. % solution in a 90/10 by weight
mixture of n-butyl acetate/xylene.
[0084] Further, the esters of the present invention are relatively
hard polymers, i.e., about 12 Knoop Hardness Units (KHU), and have
high glass transition temperatures. They can be added to other
resins to improve the coating hardness, and to improve properties
such as slip, sag resistance, and mar resistance. To further
improve the toughness, crosslinkers such as melamines or
isocyanates may be added to react with these esters or with other
resins.
[0085] The esters of the present invention may possess free
hydroxyl groups, and thus may be utilized in conjunction with
crosslinking agents such as melamines and isocyanates. Such
melamines are preferably compounds having a plurality of
--N(CH.sub.2OR).sub.2 functional groups, wherein R is
C.sub.1-C.sub.4 alkyl, preferably methyl. In general, the melamine
cross-linking agent may be selected from compounds of the following
formula, wherein R is independently C.sub.1-C.sub.4 alkyl:
##STR00003##
[0086] In this regard, preferred cross-linking agents include
hexamethoxymethylamine, tetramethoxymethylbenzo-guanamine,
tetramethoxymethylurea, mixed butoxy/methoxy substituted melamines,
and the like. The most preferred melamine cross-linking agent is
hexamethoxymethylamine.
[0087] Typical isocyanate crosslinking agents and resins include
hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI),
and toluene diisocyanate.
[0088] The cellulose esters of this invention are effective flow
additives for high solids coatings formulations. Addition of the
cellulose esters according to the invention to high solids coatings
formulations generally results in the elimination of surface
defects in the film upon curing/drying (i.e. elimination of
pinholing and orange peel). A distinct advantage that high
DS.sub.Max, low DP cellulose esters have over conventional
cellulose esters is that the inventive esters have a minimal impact
on solution and/or spray viscosity when added to high solids
coatings formulations. The percent solids can be increased, thus
reducing the VOC of the formulation. Conventional cellulose esters
can be used in these same applications as flow additives, but a
reduction in solids must generally accompany the addition of the
conventional cellulose esters. That is, the solvent level must be
increased so as to maintain a desirable viscosity.
[0089] The invention therefore relates also to coating compositions
containing the cellulose mixed esters according to the
invention.
[0090] Thus, the present invention provides a coating composition
comprising (a) about 0.1 to about 50 weight percent, based on the
total weight (a) and (b) in said composition, of a C.sub.2-C.sub.4
mixed ester of cellulose, with an inherent viscosity of about 0.05
to 0.15 dL/g, as measured in a 60/40 (wt./wt.) solution of
phenol/tetrachloroethane at 25.degree. C., and a degree of
substitution per anhydroglucose unit of C.sub.2-C.sub.4 esters of
about 1.5 to about 3.50;
[0091] (b) about 0.1 to 92 weight percent, based on the total
weight of (a) and (b) in said composition, of a resin selected from
the group consisting of polyesters, polyester-amides, cellulose
esters, alkyds, polyurethanes, epoxy resins, polyamides, acrylics,
vinyl polymers, polyisocyanates, melamines, phenolics, urea resins,
urethane resins, and polyamides; and
[0092] (c) a solvent, preferably an organic solvent, or a solvent
mixture;
[0093] wherein the total weight of (a) and (b) is about 5 to 95
weight percent of the total weight of (a), (b), and (c).
[0094] In the compositions of the invention, the total weight of
(a), (b), and (c) will of course equal 100%.
[0095] It is recognized that additional additives can be used in
the previously described compositions, including the following:
flow additives, leveling additives, wetting and dispering agents,
defoamers, adhesion promoters, slip aids, anti-skinning agents, UV
stabilizers, biocides, mildewcides, fungicides, pigments, and
others.
[0096] The mixed cellulose esters of the present invention may also
be utilized in waterborne coating compositions. For example, the
inventive esters may be dissolved in organic solvents, treated with
either an amine or a surfactant, and dispersed in water. Examples
of such solvents include, but are not limited to, 2-butanone,
methyl amyl ketone, methanol, ethanol, ethyl 3-ethoxypropionate,
ethylene glycol monoethyl ether, ethylene glycol monopropyl ether,
and ethylene glycol monobutyl ether, and the like. Dispersion of
the cellulose esters of the present invention in water is
facilitated by addition of an amine or a surfactant. Typical amines
include, but are not limited to, ammonia, piperidine,
4-ethylmorpholine, diethanolamine, triethanolamine, ethanolamine,
tributylamine, dibutylamine, and dimethylamino ethanol. Surfactants
include but are not limited to Aerosol OT, as well as other
surfactants known in the art, such as those set out below.
[0097] Examples of dispersing agents and surfactants include sodium
bis(tridecyl)sulfosuccinnate, di(2-ethyl hexyl)sodium
sulfosuccinnate, sodium dihexylsulfosuccinnate, sodium dicyclohexyl
sulfosuccinnate, diamyl sodium sulfosuccinnate, sodium diisobutyl
sulfosuccinate, disodium iso-decyl sulfosuccinnate, disodium
ethoxylated alcohol half ester of sulfosuccinnic acid, disodium
alkyl amido polyethoxy sulfosuccinnate, tetrasodium
N-(1,2-dicarboxy-ethyl)-N-oxtadecyl sulfosuccinnamate, disodium
N-octasulfosuccinnamate, sulfated ethoxylated nonylphenol,
2-amino-2-methyl-1-propanol, and the like.
[0098] Alternatively, the inventive cellulose esters may be
combined with one or more co-resins to assist dispersion. The
amount of suitable aqueous solvent in the dispersed coating
composition of such embodiments may be from about 50 to about 90 wt
%, or from about 75 to about 90 wt %, of the total coating
composition.
[0099] Thus, as a further aspect of the present invention, there is
provided a waterborne coating composition comprising: [0100] (a)
about 0.1 to about 50 weight percent, based on the total weight of
(a) and (b), of a C.sub.2-C.sub.4 ester of cellulose, exhibiting an
inherent viscosity of about 0.05 to 0.15 dL/g, as measured in a
60/40 (wt./wt.) solution of phenol/tetrachloroethane at 25.degree.
C., and having substitutions as defined elsewhere herein, wherein
the C.sub.2-C.sub.4 ester has been partially neutralized with
ammonia or an amine; [0101] (b) at least 50 weight percent, based
on the total weight of (a) and (b), of a compatible water soluble
or water dispersible resin selected from the group consisting of
polyesters, polyesteramides, cellulose esters, alkyds,
polyurethanes, epoxy resins, polyamides, acrylics, vinyl polymers,
polyurethanes, and melamines; [0102] (c) water; and [0103] (d) an
organic solvent;
[0104] wherein the total weight of (a) and (b) is between 5 and 50
weight percent of the total composition and the organic solvent
comprises less than 20 weight percent of the total weight of the
composition.
[0105] As a further aspect of the present invention, the above
compositions are further comprised of one or more coatings
additives. Such additives are generally present in a range of about
0.1 to 15 weight percent, based on the total weight of the
composition. Examples of such coatings additives include leveling,
rheology, and flow control agents such as silicones, fluorocarbons
or cellulosics; flatting agents; pigment wetting and dispersing
agents; surfactants; ultraviolet (UV) absorbers; UV light
stabilizers; tinting pigments; defoaming and antifoaming agents;
anti-settling, anti-sag and bodying agents; anti-skinning agents;
anti-flooding and anti-floating agents; fungicides and mildewcides;
corrosion inhibitors; thickening agents; or coalescing agents.
[0106] Specific examples of additional coatings additives can be
found in Raw Materials Index, published by the National Paint &
Coatings Association, 1500 Rhode Island Avenue, N.W., Washington,
D.C. 20005.
[0107] Examples of flatting agents include synthetic silica,
available from the Davison Chemical Division of W. R. Grace &
Company under the trademark SYLOID.TM.; polypropylene, available
from Hercules Inc., under the trademark HERCOFLAT.TM.; synthetic
silicate, available from J. M Huber Corporation under the trademark
ZEOLEX.TM.; and polyethylene.
[0108] Examples of dispersing agents and surfactants include sodium
bis(tridecyl) sulfosuccinnate, di(2-ethylhexyl) sodium
sulfosuccinnate, sodium dihexylsulfosuccinnate, sodium dicyclohexyl
sulfosuccinnate, diamyl sodium sulfosuccinnate, sodium diisobutyl
sulfosuccinate, disodium isodecyl sulfosuccinnate, disodium
ethoxylated alcohol half ester of sulfosuccinnic acid, disodium
alkyl amido polyethoxy sulfosuccinnate, tetrasodium
N-(1,2-dicarboxy-ethyl)-N-oxtadecyl sulfosuccinnamate, disodium
N-octasulfosuccinnamate, sulfated ethoxylated nonylphenol,
2-amino-2-methyl-1-propanol, and the like.
[0109] Examples of viscosity, suspension, and flow control agents
include polyaminoamide phosphate, high molecular weight carboxylic
acid salts of polyamine amides, and alkyl amine salt of an
unsaturated fatty acid, all are available from BYK Chemie U.S.A.
under the trademark ANTI TERRA.TM.. Further examples include
polysiloxane copolymers, polyacrylate solution, cellulose esters,
hydroxyethyl cellulose, hydrophobically modified hydroxyethyl
cellulose, hydroxypropyl cellulose, polyamide wax, polyolefin wax,
carboxymethyl cellulose, ammonium polyacrylate, sodium
polyacrylate, and polyethylene oxide.
[0110] Several proprietary antifoaming agents are commercially
available, for example, under the trademark BRUBREAK of Buckman
Laboratories Inc., under the BYK.TM. trademark of BYK Chemie,
U.S.A., under the FOAMASTER.TM. and NOPCO.TM. trademarks of Henkel
Corp./Coating Chemicals, under the DREWPLUS.TM. trademark of the
Drew Industrial Division of Ashland Chemical Company, under the
TROYSOL.TM. and TROYKYD.TM. trademarks of Troy Chemical
Corporation, and under the SAGTM trademark of Union Carbide
Corporation.
[0111] Examples of fungicides, mildewcides, and biocides include
4,4-dimethyloxazolidine, 3,4,4-trimethyl-oxazolidine, modified
barium metaborate, potassium
N-hydroxy-methyl-N-methyldithiocarbamate, 2-(thiocyano-methylthio)
benzothiazole, potassium dimethyl dithiocarbamate, adamantane,
N-(trichloromethylthio)phthalimide,
2,4,5,6-tetrachloroisophthalonitrile, orthophenyl phenol,
2,4,5-trichlorophenol, dehydroacetic acid, copper naphthenate,
copper octoate, organic arsenic, tributyl tin oxide, zinc
naphthenate, and copper 8-quinolinate.
[0112] Examples of U.V. absorbers and U.V. light stabilizers
include substituted benzophenone, substituted benzotriazole,
hindered amine, and hindered benzoate, available from American
Cyanamide Company under the trade name Cyasorb UV, and available
from Ciba Geigy under the trademark TINUVIN, and
diethyl-3-acetyl-4-hydroxy-benzyl-phosphonate,
4-dodecyloxy-2-hydroxy benzophenone, and resorcinol
monobenzoate.
[0113] To prepare coated articles according to the present
invention, a formulated coating composition containing the
cellulose esters of the present invention is applied to a substrate
and allowed to dry. The substrate can be, for example, wood;
plastic; metal, such as aluminum or steel; cardboard; glass;
cellulose acetate butyrate sheeting; and various blends containing,
for example, polypropylene, polycarbonate, polyesters such as
polyethylene terephthalate, acrylic sheeting, as well as other
solid substrates.
[0114] Pigments suitable for use in the coating compositions
according to the present invention are the typical organic and
inorganic pigments, well-known to one of ordinary skill in the art
of surface coatings, especially those set forth by the Colour
Index, 3d Ed., 2d Rev., 1982, published by the Society of Dyers and
Colourists in association with the American Association of Textile
Chemists and Colorists. Examples include, but are not limited to
the following: CI Pigment White 6 (titanium dioxide); CI Pigment
Red 101 (red iron oxide); CI Pigment Yellow 42, CI Pigment Blue 15,
15:1, 15:2, 15:3, 15:4 (copper phthalocyanines); CI Pigment Red
49:1; and CI Pigment Red 57:1.
[0115] The conventional cellulose acetate butyrates described in
this invention were commercial samples from Eastman Chemical
Company, Kingsport, Tenn., as follows: CAB-171-15, CAB-381-0.1,
CAB-381-0.5, CAB-381-20, CAB-551-0.01 and CAB-551-0.2. Commercial
CMCAB samples were from Eastman Chemical Company as follows:
CMCAB-641-0.5 and CMCAB-641-0.2.
[0116] The following commercial coating resins, representative of
those used in coatings, were used to demonstrate the compatibility
of the inventive esters with a wide variety of coatings resins:
Desmodur HL was obtained from Bayer as a 60% solution in butyl
acetate. Eastman's Polymac HS 220-2010 (polyester), Eastman's
Duramac HS 2706 (alkyd resin), Eastman's Polymac HS 5776
(polyester), Eastman's Acrylamac 232-1700 (acrylic resin), Versamid
750 (polyamide), UCAR's VYHD (polyvinyl chloride/acetate),
Eastman's Duramac 207-2706 (TOFA short oil alkyd resin), Eastman's
Duramac 5205 (coconut medium oil alkyd resin), Cytec's Cymel 303
(HMM melamine), Cytec's Beetle 65 (urea-formaldehyde), Bayer's Des
N 3300 (polyisocyante), DuPont's Epon 1001F (epoxy resin), Bayer's
Desmodur N 75 BA (aliphatic polyisocyanate), Actichem's Synocure
851 S (acrylic resin), Rohm & Haas Acryloid AT954 (acrylic
resin), R&H Acryloid B-44 (acrylic resin),R&H Paraloid A-21
(acrylic lacquer), DuPont ELVACITE 2008 (acrylic lacquer), Polymac
HS220-2010 (polyester), Cytec's BEETLE 65 (urea formaldehyde), UC
CK-2103 (phenolic), Rohm & Haas Paraloid WR97 (acrylic lacquer,
R&H Acryloid AU608X (acrylic resin), VERSAMID 750 (polyamide),
Eastman's Duramac 207-2706 (alkyd resin), Eastman's Duramac 5205
(alkyd resin), Duramac 51-5135 (alkyd resin), Duramac 207-1405
(alkyd resin), DuPont's ELVACITE 2044 (ethyl methacrylate), Bayer's
Des N 3300 (polymeric isocyanate), Eastman Reactol 175 (acrylic
polyol), Akzo Nobel Microgel (thermoset acrylic), Eastman Duramac
1205 (alkyd resin), Eastman Duramac 2706 (alkyd resin), Eastman
Duramac 2314 (alkyd resin), Resimene CE-7103 (melamine), Resimene
755 (melamine), Desmophen 1800 (polyester), Bayer Desmodur 3300
(isocyanate), Shell Epon 1001F (epoxy), Dow DER 542 (epoxy), Rhodia
XIDT (isocyanate), Bayer Desmodur IL (isocyanate), Eastman Carbamac
HS4372 (polyurethane), UCC UCAR VYHD (vinyl chloride/vinyl
acetate), UCAR VMCH (vinyl chloride/vinyl acetate), DuPont LVAX 40
(Vinyl chloride/Vinyl acetate), and Henkle Verasmid 750
(Polyamide).
[0117] In the present disclosure, the following terms have the
given meanings:
[0118] Strike-in means redissolve of the basecoat caused by the
solvents in a clearcoat and typically results in a mottled or muddy
appearance of the basecoat pigment/metal flakes.
[0119] High Solids Coatings are coatings with a higher % solids in
the formulation than traditional coatings, this typically means
coatings formulations with a % solids level greater than or equal
to 60%.
[0120] Medium Solids Coatings are coatings with a higher % solids
in the formulation than low solids coatings, this typically means
coatings formulations with a % solids level between 40% and
60%.
[0121] Low Solids Coatings are coatings with a low % solids in the
formulation, this typically means coatings formulations with a %
solids level less than 40%.
[0122] Gloss is a subjective term used to describe the relative
amount and nature of mirror like reflection.
[0123] Orange Peel is a paint surface appearance resembling an
orange skin texture.
[0124] A Surface Defect is any abnormality on the surface of a
coating that adversely affects the appearance of the coating;
examples include pinholes, craters, and orange peel.
[0125] Pinholes (Pinholing) are film surface defects characterized
by small pore-like flaws in a coating, which extend entirely
through the coating and have the general appearance of
pinpricks.
[0126] Craters are small bowl-shaped depressions frequently having
drops or bands of material at their centers and raised circular
edges in a coating film.
[0127] Cratering is the formation in a wet coating film of small
bowl-shaped depressions that persist after drying.
[0128] Dry-To-Touch Time is the interval between application and
tack-free time (i.e. the amount of time required for a coating to
feel dry.
[0129] Reducing Terminus means the terminal saccharide of a
disaccharide, trisaccharide, oligosaccharide or polysaccharide that
has no other saccharide attached at C1. The C1 can be
functionalized with either a hydroxyl group or an ester group.
[0130] Non-reducing Terminus means the terminal saccharide of a
disaccharide, trisaccharide, oligosaccharide or polysaccharide that
has no other saccharide attached at C4. The C4 can be
functionalized with either a hydroxyl group or an ester group.
[0131] Acetolysis means the cleavage of a glycosidic bond in the
absence of water and in the presence of a catalyst and a carboxylic
acid, including but not limited to acetic acid.
[0132] Hydrolysis means the cleavage of a glycosidic bond in the
presence of water and a catalyst.
[0133] Hydrolysis also means the cleavage of an ester linkage of a
cellulose ester in the presence of water and a catalyst to generate
a free hydroxyl group on the cellulosic backbone.
[0134] Travel means change in color as the angle of viewing a
goniochromatic material, such as a metallic paint film, is changed
from the perpendicular to near-grazing. Sometimes called flop or
flip-flop.
[0135] Flop means where two different painted panels appear to be a
good match for color when viewed at a given angle, but appear
different at all other angles.
[0136] Double Rub is the act of rubbing a solvent saturated cloth
in one complete forward and backward motion over the coated
surface.
[0137] Mandrel Bends is a test for determining the flexibility and
adhesion of surface coatings, so named because it involves the
bending of coated metal panels around mandrels. [adapted from ASTM
procedure D-522]
[0138] Certain of the definitions were adapted from Coatings
Encyclopedic Dictionary, ed. LeSota, S.; 1995, Federation of
Societies for Coatings Technology, Blue Bell, Pa., incorporated
herein by reference.
[0139] As used in the examples and throughout the application, MEK
means methyl ethyl ketone; MPK means methyl propyl ketone; MAK
means methyl amyl ketone; PM acetate or Eastman PM acetate means
propylene glycol methyl acetate; EB acetate or Eastman EB acetate
means ethylene glycol butyl acetate; PM or Eastman PM means
propylene glycol monomethyl ether; DM or Eastman DM means
diethylene glycol methyl ether; PB or Eastman PB means propylene
glycol monobutyl ether; DE or Eastman DE means diethylene glycol
ethyl ether; PP or Eastman PP means propylene glycol monopropyl
ether; EP Solvent or Eastman EP Solvent means ethylene glycol
monopropyl ether; EB Solvent or Eastman EB Solvent means ethylene
glycol monobutyl ether; Tecsol C, 95% means ethanol with methanol,
MIBK and ethyl acetate as denaturants with 5% water; NMP means
n-methyl pyrrolidone; and EEP Solvent or Eastman EEP Solvent means
ethyl 3-ethoxypropionate.
[0140] Experimental
[0141] The .sup.1H NMR results are obtained using a JEOL Model
GX-400 NMR spectrometer operated at 400 MHz. Sample tube size is 5
mm. The sample temperature is 80.degree. C., the pulse delay 5 sec.
and 64 scans are acquired for each experiment. Chemical shifts are
reported in ppm from tetramethylsilane, with residual DMSO as an
internal reference. The chemical shift of residual DMSO is set to
2.49 ppm.
[0142] For any carboxy(C.sub.1-C.sub.3)alkylcellulose esters, a GC
method is used to determine acetyl, propionyl, and butyryl, rather
than NMR, because the methylene of the
carboxyl(C.sub.1-C.sub.3)alkyl group cannot be separated from the
ring protons of the cellulose backbone, making absolute DS
measurements by NMR difficult. The DS values are calculated by
converting the acid number to percent carboxymethyl and using this
along with the GC weight percents of acetyl, propionyl, and
butyryl.
[0143] The acetyl, propionyl, and butyryl weight percents are
determined by a hydrolysis GC method. In this method, about 1 g of
ester is weighed into a weighing bottle and dried in a vacuum oven
at 105.degree. C. for at least 30 minutes. Then 0.500.+-.0.001 g of
sample is weighed into a 250 mL Erlenmeyer flask. To this flask is
added 50 mL of a solution of 9.16 g isovaleric acid, 99%, in 2000
mL pyridine. This mixture is heated to reflux for about 10 minutes,
after which 30 mL of isopropanolic potassium hydroxide solution is
added. This mixture is heated at reflux for about 10 minutes. The
mixture is allowed to cool with stirring for 20 minutes, and then 3
mL of concentrated hydrochloric acid is added. The mixture is
stirred for 5 minutes, and then allowed to settle for 5 minutes.
About 3 mL of solution is transferred to a centrifuge tube and
centrifuged for about 5 minutes. The liquid is analyzed by GC
(split injection and flame ionization detector) with a
25M.times.0.53 mm fused silica column with 1 .mu.m FFAP phase.
[0144] The weight percent acyl is calculated as follows, where:
[0145] C.sub.i=concentration of I (acyl group)
[0146] F.sub.i=relative response factor for component I
[0147] F.sub.s=relative response factor for isovaleric acid
[0148] A.sub.i=area of component I
[0149] A.sub.s=area of isovaleric acid
[0150] R=(grams of isovaleric acid)/(g sample)
C.sub.i=((F.sub.i*A.sub.i)/F.sub.s*A.sub.s))*R*100
[0151] This GC method is used, along with NMR, to determine weight
% acetyl, propionyl, and butyryl, and the method used is
indicated.
[0152] We note that wt. % substitutions may be converted to degree
of substitution (DS) values, according to the following:
[0153] Wt. % Butyryl is calculated using the following
equation:
Wt. %
Bu=(DS.sub.Bu*MW.sub.Bu)/((DS.sub.Ac*MW.sub.AcKet)+(DS.sub.Bu*MW.s-
ub.BuKet)+MW.sub.anhydroglu)
[0154] Wt. % Acetyl is calculated using the following equation:
Wt. %
Ac=(DS.sub.Ac*MW.sub.Ac)/((DS.sub.Ac*MW.sub.AcKet)(DS.sub.Bu*MW.su-
b.BuKet)+MW.sub.anhydroglu)
[0155] Wt. % Hydroxyl is calculated using the following
equation:
Wt. %
OH=(DS.sub.Max-DS.sub.Ac-DS.sub.Bu)*MW.sub.OH/((DS.sub.Ac*MW.sub.A-
cKet)+(DS.sub.Bu*MW.sub.BuKet)+MW.sub.anhydroglu)
[0156] Unless otherwise noted:
[0157] DS.sub.Ac=Degree of substitution of butyryl as determined by
.sup.1H-NMR
[0158] DS.sub.Bu=Degree of substitution of butyryl as determined by
.sup.1H-NMR
[0159] MW.sub.Ac=Molecular weight of the acetyl ester,
(C.sub.2H.sub.3O=43.045)
[0160] MW.sub.Bu=Molecular weight of the butyryl ester,
(C.sub.4H.sub.7O=71.095)
[0161] MW.sub.OH=Molecular weight of the hydroxyl group,
(OH=17.007)
[0162] MW.sub.AcKet=Molecular weight of the acetyl ester minus one
hydrogen, (C.sub.2H.sub.2O=42.037)
[0163] MW.sub.BuKet=Molecular weight of the acetyl ester minus one
hydrogen, (C.sub.4H.sub.6O=70.091)
[0164] MW.sub.anhydroglu=Molecular weight of the anhydroglucose
unit, (C.sub.6H.sub.10O.sub.5=162.141)
[0165] DS.sub.Max=Maximum degree of substitution (DS.sub.Max is
assumed to be 3.22 for all calculations, to be more accurate, the
degree of polymerization should be determined and the DS.sub.Max
used in the calculations should be appropriately adjusted. To
simplify the calculations, a DS.sub.Max of 3.22 is assumed. As is
evidenced by the negative values of Wt % Hydroxyl for several of
the HS-CAB samples that were isolated in the fully esterified
state, 3.22 is not completely accurate.
[0166] Wt. % Propionyl cannot be determined from DS data obtained
by .sup.1H-NMR since the peaks generated by the propionyl protons
overlap with those generated by the butyryl protons. As a result,
it is always assumed that the peaks are generated by the ester of
interest (i.e. a butyryl ester in the case of a CAB or a propionyl
ester in the case of a CAP).
[0167] We use one of two methods to determine the degree of
substitution (DS) of the inventive cellulose mixed esters and
conventional cellulose esters.
[0168] Method 1 determines the degree of substitution of acetyl and
of butyryl by analyzing the NMR spectrum and comparing the peak
area of the integrated alkyl ester protons with the peak area of
the cellulose backbone protons. According to this method, acetyl
can be distinguished from the higher esters such as butyryl or
propionyl, but butyryl cannot be distinguished from propionyl. As a
result, one must assume that all the higher esters peaks come from
either butyryl or propionyl, depending upon the anhydride used.
This is a reasonable assumption for cellulose acetate butyrates
since the level of propionyl in CAB's is near zero when butyric
anhydride is a reactant. Another issue is that with this method,
.sup.1H-NMR does not indicate the degree of substitution of
hydroxyl groups. The accepted method for determining the degree of
substitution of hydroxyl groups is by difference, that is, one
assumes a maximum degree of substitution and from that number
subtracts the degree of substitution of acetyl and butyryl. The
result is the degree of substitution of hydroxyl groups, seen in
the following equation 1.
DS.sub.Max-DS.sub.Bu-DS.sub.Ac=DS.sub.OH Equation 1:
[0169] Ester substitutions for conventional molecular weight
cellulose esters are easily calculated. Since they have a higher
degree of substitution, it is accepted that the DS.sub.Max is 3.0.
For the inventive mixed esters according to the invention, the
maximum degree of substitution is greater than 3.0 and is on a
steeper part of the curve, that is small changes in DP have a
greater impact on DS.sub.Max than is seen with conventional esters.
As a result, in order to obtain an accurate measure of the
DS.sub.Max and ultimately the DS.sub.OH, one should first determine
the degree of polymerization (based on molecular weight), and use
that information to determine the DS.sub.max. Throughout this
application, the DS.sub.max is assumed to be equal to 3.22 for this
purpose. This is a reasonable number that would be obtained with a
degree of polymerization of anhydroglucose units equal to 9.
Unfortunately, DS.sub.Max=3.22 is not an accurate assumption for
all HS-CAB samples, and in some cases (see Examples 9-27) the
calculated DS.sub.OH would be less than zero. We therefore
sometimes describe an upper hydroxyl content of the cellulose mixed
esters according to the invention, while omitting the lower
value.
[0170] Method 2 utilizes the weight percent data determined by GC
(acetyl, propionyl, and butyryl) and by titration (hydroxyl), and
DS values are calculated from these data. The uncertainty with the
use of this method is that the DS calculations are dependent on the
accuracy and precision of the GC and titration test methods. As a
result, in some cases when this method is used to determine degree
of substitution, the calculated DS.sub.Max is less than 3.0.
[0171] We are presenting both wt % and degree of substitution in
the application, in certain instances, in an effort to describe the
inventive esters as completely as possible. Unless stated
otherwise, DS results are from NMR data, wt acetyl, propionyl and
butyryl are from gas chromatography analysis, and wt % hydroxyl
values are from titration data.
[0172] The acid number of any
carboxy(C.sub.1-C.sub.3)alkylcellulose esters are determined by
titration as follows. An accurately weighed aliquot (0.5-1.0 g) of
the carboxy (C.sub.1-C.sub.3) alkylcellulose ester is mixed with 50
mL of pyridine and stirred. To this mixture is added 40 mL of
acetone followed by stirring. Finally, 20 mL of water is added and
the mixture stirred again. This mixture is titrated with 0.1 N
sodium hydroxide in water using a glass/combination electrode. A
blank consisting of 50 mL of pyridine, 40 mL of acetone, and 20 mL
of water is also titrated. The acid number is calculated as follows
where:
[0173] Ep=mL NaOH solution to reach end point of sample
[0174] B=mL NaOH solution to reach end point of blank
[0175] N=normality of sodium hydroxide solution
[0176] Wt.=weight of carboxy (C.sub.1-C.sub.3) alkylcellulose ester
titrated.
Acid Number (mg KOH/g sample)=((Ep-B)*N*56.1)/Wt.
[0177] IV Test Method
[0178] The inherent viscosity (IV) of the cellulose esters
described in this application, except where indicated otherwise,
are determined by measuring the flow time of a solution of known
polymer concentration and the flow time of a solvent-blank in a
capillary viscometer, and then calculating the IV.
[0179] IV is defined by the following equation:
( n ) 25 .degree. C . 0.50 % = ln ts to C ##EQU00001## [0180]
where: [0181] (n)=Inherent Viscosity at 25.degree. C. at a polymer
concentration of 0.50 g/100 mL of solvent. [0182] ln=Natural
logarithm [0183] t.sub.s=Sample flow time [0184]
t.sub.o=Solvent-blank flow time [0185] C=Concentration of polymer
in grams per 100 mL of solvent=0.50
[0186] Samples are prepared to a concentration of 0.50 g per 100 mL
of solvent (60% phenol and 40% 1,1,2,2-tetrachloroethane by weight,
also described herein as "PM95"). The sample (0.25 g) is weighed
into a culture tube containing a stir bar. 50.0 mL of 60% phenol
and 40% 1,1,2,2-tetrachloroethane by weight (also described in the
application as "PM95") is added. The mixture is placed in a heater
and heated with stirring (300 rpm) to 125.degree. C. (7 minutes to
reach the target temperature and 15 minute hold at 125.degree. C.).
The sample is allowed to cool to room temperature (25.degree. C.)
and is then filtered and placed in the viscometer (Model AVS
500--Schott America, Glass & Scientific Products, Inc.,
Yonkers, N.Y.). IV is calculated according to the equation
above.
[0187] Solution Viscosity Determination
[0188] A few solution viscosity values are provided in the present
application, because the method has been used in the literature to
measure viscosity, and inferentially, molecular weight. We note,
however, that solution viscosity measurements of the low molecular
weight esters of the invention are less meaningful than are the
inherent viscosity measurements as set forth above. We therefore
provide solution viscosity measurements for comparison purposes
only, and not as a preferred method of inferring molecular weight.
Unless otherwise indicated, solution viscosity values are measured
according to ASTM-D 817.
[0189] GPC Method for Molecular Weight Determination
[0190] The molecular weight distributions of cellulose ester and
carboxy(C.sub.1-C.sub.3)alkylcellulose ester samples are determined
by gel permeation chromatography (GPC) using one of two methods
listed below.
[0191] Method 1, THF: The molecular weight distributions of
cellulose ester samples indicated as being tested by GPC with THF
as a solvent are determined at ambient temperature in Burdick and
Jackson GPC-grade THF stabilized with BHT, at a flow rate of 1
ml/min. All other samples are determined using GPC with NMP as a
solvent, as set forth in Method 2 below. Sample solutions are
prepared by dissolution of about 50 mg of polymer in 10 ml of THF,
to which 10 .mu.l of toluene is added as a flow-rate marker. An
autosampler is used to inject 50 .mu.l of each solution onto a
Polymer Laboratories PLgel.RTM. column set consisting of a 5 .mu.m
Guard, a Mixed-C.RTM. and an Oligopore.RTM. column in series. The
eluting polymer is detected by differential refractometry, with the
detector cell held at 30.degree. C. The detector signal is recorded
by a Polymer Laboratories Caliber.RTM. data acquisition system, and
the chromatograms are integrated with software developed at Eastman
Chemical Company. A calibration curve is determined with a set of
eighteen nearly monodisperse polystyrene standards with molecular
weight from 266 to 3,200,000 g/mole and 1-phenylhexane at 162
g/mole. The molecular weight distributions and averages are
reported either as equivalent polystyrene values or as true
molecular weights calculated by means of a universal calibration
procedure with the following parameters: [0192] K.sub.PS=0.0128
a.sub.PS=0.712 [0193] K.sub.CE=0.00757 a.sub.CE=0.842
[0194] Method 2, NMP: The molecular weight distributions of all
samples not otherwise indicated are determined by GPC with NMP as a
solvent, as follows. The molecular weight distributions of
cellulose ester samples are determined by gel permeation
chromatography at 40.degree. C. in Burdick and Jackson
N-Methylpyrrolidone with 1% Baker glacial acetic acid by weight, at
a flow rate of 0.8 ml/min. Sample solutions are prepared by
dissolution of about 25 mg of polymer in 10 ml of NMP, to which 10
.mu.l of toluene is added as a flow-rate marker. An autosampler is
used to inject 20 .mu.l of each solution onto a Polymer
Laboratories PLgel.RTM. column set consisting of a 10 .mu.m Guard,
a Mixed-B.RTM. column. The eluting polymer is detected by
differential refractometry, with the detector cell held at
40.degree. C. The detector signal is recorded by a Polymer
Laboratories Caliber.RTM. data acquisition system, and the
chromatograms are integrated with software developed at Eastman
Chemical Company. A calibration curve is determined with a set of
eighteen nearly monodisperse polystyrene standards with molecular
weight from 580 to 3,200,000 g/mole. The molecular weight
distributions and averages are reported as equivalent polystyrene
values.
[0195] The invention can be further illustrated by the following
examples of preferred embodiments, although it will be understood
that these examples are included merely for purposes of
illustration and are not intended to limit the scope of the
invention unless otherwise specifically indicated.
EXAMPLES
Example 1
Preparation of a Mid-Butyryl Cellulose Ester (HS-CAB-38) According
to the Invention
[0196] Cellulose (80 g), provided as a dissolving grade of softwood
pulp with an .alpha.-cellulose content of at least 94%, was
activated by soaking in water (.about.1000 mL) in excess of 20
minutes, and then filtering through a fritted funnel to remove the
water. Residual water was removed by washing the water-wet
cellulose with acetic acid (.about.2000 mL). The acetic acid-wet
cellulose was then washed with butyric acid (.about.2000 mL). A 2
L-reaction kettle was charged with the butyric acid-wet activated
cellulose (311.67 g). Butyric acid (145.8 g) was added to the
kettle. The mixture was cooled to 15.degree. C. A mixture of
butyric anhydride (225.9 g), acetic anhydride (96.8 g), and
sulfuric acid (3.42 g) were cooled to 15.degree. C. and then added
to the reaction kettle. The mixture was stirred for 1 hour at room
temperature. The mixture was then heated to 84.2.degree. C. and
stirred for 11.5 hours. A mixture of water (150 g) and acetic acid
(105 g) was slowly added to the clear "dope." The mixture was
stirred for 7.5 hours at 65.degree. C. The catalyst was neutralized
by the addition of Mg(OAc).sub.4 (4.5 g) and NaOAc (1.7 g)
dissolved in acetic acid (HOAc) (5.25 g) and water (19 g). The
neutralized dope was filtered at approximately 50.degree. C.
through a glass wool-covered coarse fritted funnel. The product was
precipitated by pouring, with rapid mixing, the clear, neutralized
dope into 20-30 volumes of water. Decanting away the filtration
liquid and adding fresh deionized water and then allowing the
precipitate to stand in the fresh water for several hours hardened
the precipitate. The precipitate was washed extensively with
deionized water for at least 4 hours. The product was dried in a
vacuum oven at approximately 50.degree. C. overnight to yield 95 g
of the final product. The product had the following composition:
DS.sub.Bu=1.92; DS.sub.Ac=0.98; M.sub.n=3012; M.sub.w=5296;
Polydispersity=1.758; IV (PM95)=0.077; S=38.2 ppm; Mg=12.9 ppm;
Na=9.7 ppm [Calculated results: wt. % Bu=40.40%, wt. % Ac=12.48%,
wt. %. OH=1.61%].
Example 2
Preparation of a Mid-Butyryl Cellulose Ester (HS-CAB-38) According
to the Invention
[0197] Cellulose (80 g), provided as a dissolving grade of softwood
pulp with an .alpha.-cellulose content of at least 94%, was
activated by soaking in water (.about.1000 mL) for at least 20
minutes and then filtering through a fritted funnel to remove the
water. Residual water was removed by washing the water-wet
cellulose with acetic acid (.about.2000 mL). The acetic acid-wet
cellulose was then washed with butyric acid (.about.2000 mL). A 2
L-reaction kettle was charged with the butyric acid-wet activated
cellulose (415 g). Butyric acid (46.6 g) was added to the kettle.
The mixture was cooled to 15.degree. C. A mixture of butyric
anhydride (246.4 g), acetic anhydride (98.8 g), and sulfuric acid
(3.42 g) were cooled to 15.degree. C. and then added to the
reaction kettle. The mixture was stirred for 1 hour at room
temperature. The mixture was then heated to 78.3.degree. C. and
stirred for 11.2 hours. A mixture of water (156 g) and acetic acid
(109 g) was slowly added to the clear "dope." The mixture was
stirred for 7.5 hours at 65.degree. C. The catalyst was neutralized
by the addition of Mg(OAc).sub.4 (4.5 g) and NaOAc (1.7 g)
dissolved in HOAc (5.25 g) and water (19 g). The neutralized dope
was filtered at approximately 50.degree. C. through a glass
wool-covered coarse fritted funnel. The product was precipitated by
pouring, with rapid mixing, the clear, neutralized dope into 20-30
volumes of water. Decanting away the filtration liquid and adding
fresh deionized water and then allowing the precipitate to stand in
the fresh water for several hours hardened the precipitate. The
precipitate was washed extensively with deionized water for at
least 4 hours. The product was dried in a vacuum oven at
approximately 50.degree. C. overnight to yield 132 g of the final
product. The product had the following composition: DS.sub.Bu=1.78;
DS.sub.Ac=1.04; M.sub.n=4448; M.sub.w=9691; Polydispersity=2.179;
IV (PM 95)=0.121; S=81.2 ppm; Mg=37.1 ppm; Na=23.3 ppm. [Calculated
results: wt. % Bu=38.28%, wt. % Ac=13.54%, wt. % OH=2.06%].
Example 3
Preparation of a High-Butyryl Cellulose Ester (HS-CAB-55) According
to the Invention
[0198] Cellulose (80 g), provided as a dissolving grade of softwood
pulp with an .alpha.-cellulose content of at least 94%, was
activated by soaking in water (.about.1000 mL) for at least 20
minutes and then filtering through a fritted funnel to remove the
water. Residual water was removed by washing the water-wet
cellulose with acetic acid (.about.2000 mL). The acetic acid-wet
cellulose was then washed with butyric acid (.about.2000 mL). A 2
L-reaction kettle was charged with the butyric acid-wet activated
cellulose (390.33 g). Butyric acid (70.3 g) was added to the
kettle. The mixture was cooled to 15.degree. C. A mixture of
butyric anhydride (396.1 g), acetic anhydride (0 g), and sulfuric
acid (3.24 g) were cooled to 15.degree. C. and then added to the
reaction kettle. The mixture was stirred for 1 hour at room
temperature. The mixture was then heated to 87.4.degree. C. and
stirred for 11.0 hours. A mixture of water (164 g) and acetic acid
(115 g) was slowly added to the clear "dope." The mixture was
stirred for 23 hours at 65.degree. C. The catalyst was neutralized
by the addition of Mg(OAc).sub.4 (4.3 g) and NaOAc (1.6 g)
dissolved in HOAc (5.25 g) and water (19 g). The neutralized dope
was filtered at approximately 50.degree. C. through a glass
wool-covered coarse fritted funnel. The product was precipitated by
pouring, with rapid mixing, the clear, neutralized dope into 20-30
volumes of water. Decanting away the filtration liquid and adding
fresh deionized water and then allowing the precipitate to stand in
the fresh water for several hours hardened the precipitate. The
precipitate was washed extensively with deionized water for at
least 4 hours. The product was dried in a vacuum oven at
approximately 50.degree. C. overnight to yield 110 g of the final
product. The product had the following composition: DS.sub.Bu=2.66;
DS.sub.Ac=0.09; M.sub.n=3492; M.sub.w=6170; Polydispersity=1.767;
IV (PM 95)=0.086; S=44 ppm; Mg=7.7 ppm; Na=6.9 ppm. [Calculated
results: wt. % Bu=53.67%, wt. % Ac=1.10%, wt. % OH=2.27%].
Example 4
Preparation of a High-Butyryl Cellulose Ester (HS-CAB-55) According
to the Invention
[0199] Cellulose (80 g), provided as a dissolving grade of softwood
pulp with an .alpha.-cellulose content of at least 94%, was
activated by soaking in water (.about.1000 mL) for at least 20
minutes and then filtering through a fritted funnel to remove the
water. Residual water was removed by washing the water-wet
cellulose with acetic acid (.about.2000 mL). The acetic acid-wet
cellulose was then washed with butyric acid (.about.2000 mL). A 2
L-reaction kettle was charged with the butyric acid-wet activated
cellulose (346.0 g). Butyric acid (112.8 g) was added to the
kettle. The mixture was cooled to 15.degree. C. A mixture of
butyric anhydride (399.0 g), acetic anhydride (0 g), and sulfuric
acid (3.24 g) were cooled to 15.degree. C. and then added to the
reaction kettle. The mixture was stirred for 1 hour at room
temperature. The mixture was then heated to 82.6.degree. C. and
stirred for 11.0 hours. A mixture of water (164 g) and acetic acid
(115 g) was slowly added to the clear "dope." The mixture was
stirred for 23 hours at 65.degree. C. The catalyst was neutralized
by the addition of Mg(OAc).sub.4 (4.3 g) and NaOAc (1.6 g)
dissolved in HOAc (5.25 g) and water (19 g). The neutralized dope
was filtered at approximately 50.degree. C. through a glass
wool-covered coarse fritted funnel. The product was precipitated by
pouring, with rapid mixing, the clear, neutralized dope into 20-30
volumes of water. Decanting away the filtration liquid and adding
fresh deionized water and then allowing the precipitate to stand in
the fresh water for several hours hardened the precipitate. The
precipitate was washed extensively with deionized water for at
least 4 hours. The product was dried in a vacuum oven at
approximately 50.degree. C. overnight to yield 136 g of the final
product. The product had the following composition: DS.sub.Bu=2.62;
DS.sub.Ac=0.05; M.sub.n=4137; M.sub.w=8715; Polydispersity=2.106;
IV (PM 95)=0.111; S=174.1; Mg=79.5; Na=65.1 [Calculated results:
wt. % Bu=53.55%, wt. % Ac=0.62%, wt. % OH=2.69%].
Example 5
Preparation of a Fully-Esterified, Low-Butyryl Cellulose Ester
(HS-CAB-17) According to the Invention
[0200] A 2 L-reaction kettle was charged with a butyric acid-wet,
water-activated cellulose (457.14 g), prepared according to Example
1. Butyric acid (18.10 g) and acetic acid (55.58 g) were added to
the kettle. The mixture was cooled to 0.degree. C. A mixture of
butyric anhydride (572.00 g), acetic anhydride (145.60 g), and
sulfuric acid (5.28 g) were cooled to -15.degree. C. and then added
to the reaction kettle. The mixture was stirred for 1 hour at room
temperature. The mixture was then heated to 62.8.degree. C. and
stirred for 24 hours. The catalyst was neutralized by the addition
of Mg(OAc).sub.4 (42.29 g) dissolved in HOAc (500 g) and water (500
g). The product was precipitated by pouring the clear, neutralized
dope with rapid mixing, into 20-30 volumes of water. The
precipitate was washed extensively with deionized water for at
least 4 hours. The product was dried in a vacuum oven at
approximately 50.degree. C. overnight. The product had the
following composition: DS.sub.Bu=1.07; DS.sub.Ac=2.22;
DS.sub.Max=3.29; M.sub.n=5575; M.sub.w=10969; Polydispersity=1.97;
IV (PM 95)=0.122 [Calculated results: wt. % Bu=23.02%, wt. %
Ac=28.92%, wt. % OH=-0.36%].
Example 6
Preparation of a Fully-Esterified Low-Butyryl Cellulose Ester
(HS-CAB-17) According to the Invention
[0201] A 2 L-reaction kettle was charged with a butyric acid-wet,
water-activated cellulose (457.14 g) (prepared according to Example
1). Butyric acid (18.10 g) and acetic acid (55.58 g) were added to
the kettle. The mixture was cooled to 0.degree. C. A mixture of
butyric anhydride (572.00 g), acetic anhydride (145.60 g), and
sulfuric acid (5.28 g) were cooled to -15.degree. C. and then added
to the reaction kettle. The mixture was stirred for 1 hour at room
temperature. The mixture was then heated to 79.4.degree. C. and
stirred for 21.2 hours. The catalyst was neutralized by the
addition of Mg(OAc).sub.4 (42.29 g) dissolved in HOAc (500 g) and
water (500 g). The product was precipitated by pouring the clear,
neutralized dope with rapid mixing, into 20-30 volumes of water.
The precipitate was washed extensively with deionized water for
approximately 15 hours. The product was dried in a vacuum oven at
approximately 50.degree. C. overnight. The product had the
following composition: DS.sub.Bu=1.13; DS.sub.Ac=2.34;
DS.sub.Max=3.47; M.sub.n=2837; M.sub.w=4401; Polydispersity=1.55;
IV (PM 95)=0.062. [Calculated results: wt. % Bu=23.65%, wt. %
Ac=29.65%, wt. % OH=-1.25%].
Example 7
Preparation of a Fully-Esterified Mid-Butyryl Cellulose Ester
(HS-CAB-38) According to the Invention
[0202] A 2 L-reaction kettle was charged with a butyric acid-wet,
water-activated cellulose (163.00 g), prepared according to Example
1. Butyric acid (13.70 g) was added to the kettle. The mixture was
cooled to 0.degree. C. A mixture of butyric anhydride (196.90 g),
acetic anhydride (71.69 g), and sulfuric acid (2.64 g) were cooled
to -15.degree. C. and then added to the reaction kettle. The
mixture was stirred for 1 hour at room temperature. The mixture was
then heated to 71.1.degree. C. and stirred for 2 hours. The
catalyst was neutralized by the addition of Mg(OAc).sub.4 (42.29 g)
dissolved in HOAc (500 g) and water (500 g). The product was
precipitated by pouring the clear, neutralized dope with rapid
mixing, into 20-30 volumes of water. The precipitate was washed
extensively with deionized water for at least 4 hours. The product
was dried in a vacuum oven at approximately 50.degree. C.
overnight. The product had the following composition:
DS.sub.Bu=1.91; DS.sub.Ac=1.43; DS.sub.Max=3.34; M.sub.n=4031;
M.sub.w=10343; Polydispersity=2.57; IV (PM 95)=0.089. [Calculated
results: wt. % Bu=38.13%, wt. % Ac=17.28%, wt. % OH=-0.57%].
Example 8
Preparation of a Fully-Esterified, High-Butyryl Cellulose Ester
(HS-CAB-55) According to the Invention
[0203] A 2 L-reaction kettle was charged with a butyric acid-wet,
water-activated cellulose (338.70 g), prepared according to Example
1. Butyric acid (22.78 g) was added to the kettle. The mixture was
cooled to 0.degree. C. A mixture of butyric anhydride (614.41 g),
acetic anhydride (0.61 g), and sulfuric acid (5.28 g) were cooled
to -15.degree. C. and then added to the reaction kettle. The
mixture was stirred for 1 hour at room temperature. The mixture was
then heated to 79.4.degree. C. and stirred for 5 hours. The
catalyst was neutralized by the addition of Mg(OAc).sub.4 (42.29 g)
dissolved in HOAc (500 g) and water (500 g). The product was
precipitated by pouring the clear, neutralized dope with rapid
mixing, into 20-30 volumes of water. The precipitate was washed
extensively with deionized water for at least 4 hours. The product
was dried in a vacuum oven at approximately 50.degree. C.
overnight. The product had the following composition:
DS.sub.Bu=3.18; DS.sub.Ac=0.04; DS.sub.Max=3.22; M.sub.n=5113;
M.sub.w=11977; Polydispersity=2.34; IV (PM 95)=0.111. [Calculated
results: wt. % Bu=58.47%, wt. % Ac=0.45%, wt. % OH=0.00%].
Examples 9-27
HS-CAB Samples
[0204] According to Examples 9-27, additional HS-CAB's of a range
of compositions are prepared and evaluated. The samples evaluated
are described in Tables 2-3, along with data from Examples 1-8 set
forth above, and are prepared as described generally elsewhere in
the specification and in Examples 1-8.
TABLE-US-00002 TABLE 2 HS-CAB Samples Example CAB Wt % Wt % Wt % Wt
% IV # Type Bu DS Bu Ac DS Ac Pr DS Pr OH DS OH (PM95) Mn Tg 1
HS-CAB-38 40.40.sup.1 1.92 12.48.sup.2 0.98 NA.sup.3 NA 1.61.sup.4
0.32.sup.5 0.077 3012.sup.6 NM 2 HS-CAB-38 38.28.sup.1 1.78
13.54.sup.2 1.04 NA.sup.3 NA 2.06.sup.4 0.4.sup.5 0.121 4448.sup.6
NM 3 HS-CAB-55 53.67.sup.1 2.66 1.10.sup.2 0.09 NA.sup.3 NA
2.27.sup.4 0.47.sup.5 0.086 3492.sup.6 NM 4 HS-CAB-55 53.55.sup.1
2.62 0.62.sup.2 0.05 NA.sup.3 NA 2.69.sup.4 0.55.sup.5 0.111
4137.sup.6 NM 5 HS-CAB-20 23.02.sup.1 1.07 28.92.sup.2 2.22
NA.sup.3 NA -0.36.sup.4 -0.07.sup.5 0.122 5575.sup.6 NM 6 HS-CAB-20
23.65.sup.1 1.13 29.65.sup.2 2.34 NA.sup.3 NA -1.25.sup.4
-0.25.sup.5 0.062 2837.sup.6 NM 7 HS-CAB-38 38.13.sup.1 1.91
17.28.sup.2 1.43 NA.sup.3 NA -0.57.sup.4 -0.12.sup.5 0.089
4031.sup.6 NM 8 HS-CAB-55 58.47.sup.1 3.18 0.45.sup.2 0.04 NA.sup.3
NA 0.00.sup.4 0.sup.5 0.111 5113.sup.6 NM 9 HS-CAB-20 22.87 1.01
27.45 2.21 0.71 NA 0.81 0.sup.5 0.071 1556 83.38 10 HS-CAB-20 21.71
1.04 23.93 2.08 0.00 NA 1.32 0.1.sup.5 0.074 1812 90.98 11
HS-CAB-20 24.25 1.12 21.12 1.78 0 NA 2.31 0.32.sup.5 0.091 1838
101.71 12 HS-CAB-20 23.99 1.08 21.43 1.72 0 NA 3.23 0.42.sup.5
0.091 2152 107.55 13 HS-CAB-20 24.31 NM 20.79 NM 0.55 NA 3.58 NM
0.093 1823 112.41 14 HS-CAB-29 29.38 1.40 18.37 1.55 0.38 NA 1.81
0.27.sup.5 0.085 NM 100.80
TABLE-US-00003 TABLE 3 HS-CAB Samples Example CAB Wt % Wt % Wt % Wt
% IV # Type Bu DS Bu Ac DS Ac Pr DS Pr OH DS OH (PM95) Mn Tg 15
HS-CAB-29 28.72 1.18 17.17 1.27 0.56 NA 3.83 0.77.sup.5 0.111 NM
120.37 16 HS-CAB-38 41.52 NM 12.52 NM 0.33 NA 0.79 NM 0.079 2040
85.03 17 HS-CAB-38 39.73 1.99 11.50 1.06 0.37 NA 1.13 0.17.sup.5
0.086 2340 95.06 18 HS-CAB-38 38.16 NM 13.06 NM 0.41 NA 1.4 NM
0.102 2734 102.72 19 HS-CAB-38 39.51 1.51 11.21 0.95 0.28 NA 2.16
0.76.sup.5 0.095 2465 NM 20 HS-CAB-38 35.01 1.63 13.42 0.94 0.77 NA
3.51 0.65.sup.5 0.103 NM 115.92 21 HS-CAB-46 47.36 2.40 6.44 0.46
0.42 NA 2.23 0.36.sup.5 NM 2499 80.72 22 HS-CAB-46 44.18 2.13 7.24
0.49 0.5 NA 3.1 0.60.sup.5 0.112 3182 99.17 23 HS-CAB-55 53.88 2.91
2.52 0.13 0.33 NA 1.09 0.18.sup.5 0.076 NM 75.27 24 HS-CAB-55 54.10
2.91 2.21 0.19 0.33 NA 1.19 0.12.sup.5 0.077 2265 76.07 25
HS-CAB-55 51.82 NM 2.85 NM 0.44 NA 2.49 NM 0.107 3222 92.25 26
HS-CAB-55 54.59 2.38 2.36 0.13 0.36 NA 3.10 0.71.sup.5 0.101 2783
99.17 27 HS-CAB-55 45.39 2.11 3.56 0.18 0.41 NA 4.61 0.93.sup.5 NM
NM 114.43 .sup.1Wt. % Butyryl is calculated using the following
equation: Wt. % Bu = (DS.sub.Bu * MW.sub.Bu)/((DS.sub.Ac *
MW.sub.AcKet) + (DS.sub.Bu * MW.sub.BuKet) + MW.sub.anhydroglu)
.sup.2Wt. % Acetyl is calculated using the following equation: Wt.
% Ac = (DS.sub.Ac * MW.sub.Ac)/((DS.sub.Ac * MW.sub.AcKet) +
(DS.sub.Bu * MW.sub.BuKet) + MW.sub.anhydroglu) .sup.3DS.sub.Pr
cannot be distinguished from butyryl from DS data obtained by
.sup.1H-NMR, since the peaks generated by the propionyl protons
overlap with those generated by the butyryl protons. As a result,
it is assumed that the peaks are generated by the ester of interest
(i.e. a butyryl ester in the case of a CAB or a propionyl ester in
the case of a CAP). .sup.4Wt. % Hydroxyl is calculated using the
following equation: Wt. % OH = (DS.sub.Max - DS.sub.Ac - DS.sub.Bu)
* MW.sub.OH/((DS.sub.Ac * MW.sub.AcKet) + (DS.sub.Bu *
MW.sub.BuKet) + MW.sub.anhydroglu) .sup.5DS.sub.OH is calculated
using the following equation: DS.sub.OH = DS.sub.Max - DS.sub.Ac -
DS.sub.Bu .sup.6These GPC results are obtained using NMP as the
solvent as opposed to THF. There is a bias between these two
methods and NMP results tend to be higher than those in THF.
DS.sub.Ac = Degree of substitution of butyryl as determined by
.sup.1H-NMR DS.sub.Bu = Degree of substitution of butyryl as
determined by .sup.1H-NMR MW.sub.Ac = Molecular weight of the
acetyl ester, (C.sub.2H.sub.3O = 43.045) MW.sub.Bu = Molecular
weight of the butyryl ester, (C.sub.4H.sub.7O = 71.095) MW.sub.OH =
Molecular weight of the hydroxyl group, (OH = 17.007) MW.sub.AcKet
= Molecular weight of the acetyl ester minus one hydrogen,
(C.sub.2H.sub.2O = 42.037) MW.sub.BuKet = Molecular weight of the
acetyl ester minus one hydrogen, (C.sub.4H.sub.6O = 70.091)
MW.sub.anhydroglu = Molecular weight of the anhydroglucose unit,
(C.sub.6H.sub.10O.sub.5 = 162.141) DS.sub.Max = Maximum degree of
substitution (DS.sub.Max is assumed to be 3.22 for all
calculations, to be more accurate, the degree of polymerization
could be determined and the DS.sub.Maxused in the calculations
appropriately adjusted. To simplify the calculations, a DS.sub.Max
of 3.22 is assumed. As is evidenced by the negative values of Wt %
Hydroxyl for several of the HS-CAB samples isolated in the fully
esterified state, 3.22 is not completely accurate. NA = Not
available from data collected NM = Not measured
Examples 28-30 and Comparative Examples 31-33
[0205] The HS-CAB samples and commercial CAB samples (available
from Eastman Chemical Company), as set forth in Table 4, are
dissolved in a variety of solvents and solvent blends (see Table 5
and 6) at 10% by weight at approximately 22.degree. C. (72.degree.
F.) (room temperature). The samples are checked visually for
solubility and rated as soluble-clear (9), soluble-slight haze (7),
gels (5), partially soluble (3), and insoluble (1). The inventive
cellulose esters are considerably more soluble in some solvents
than current commercial cellulose esters of similar acetyl/butyryl
content (e.g. CAB-381-0.1, CAB-551-0.01, and CAB-171-15, all
available from Eastman Chemical Company, Kingsport, Tenn.),
particularly the HS CAB-38 and HS CAB-17 type ester for the
following solvents: toluene, methanol, ethanol, isopropyl alcohol,
Eastman EB, Eastman EP, PB, PP, DIBK, C-11 ketone, EB acetate, PM
acetate, and n-butyl acetate.
TABLE-US-00004 TABLE 4 Properties of HS-CAB's evaluated Sample # 1
2 3 4 5 6 Ester Type HS-CAB-38 HS-CAB-55 HS-CAB-17* HS-CAB-38
HS-CAB-55 HS-CAB-55 % Acetyl (GC) 9.99 2.93 24.85 NA NA NA %
Butyryl (GC) 41.07 51.41 20.42 NA NA NA % Propionyl (GC) 0.28 0.41
0.38 NA NA NA % Hydroxyl (titration) 1.40 2.2 3.83 NA NA NA DS
Acetyl (NMR) 1.00 0.07 1.70 1.00 0.07 0.05 DS Butyryl (NMR) 2.06
2.73 0.91 1.94 2.70 2.72 DS CM 0 0 0 0 0 0 IV (PM 95) 0.096 0.088
0.091 0.096 0.088 0.119 M.sub.n 1775.sup..dagger. 2274.sup..dagger.
2529.sup..dagger. 3175.sup..dagger..dagger.
3349.sup..dagger..dagger. 4098.sup..dagger..dagger. M.sub.w
3159.sup..dagger. 3636.sup..dagger. 3998.sup..dagger.
5551.sup..dagger..dagger. 6066.sup..dagger..dagger.
8149.sup..dagger..dagger. .sup..dagger.Calculatedby GPC w/ THF as
solvent. .sup..dagger..dagger.Calculated by GPC w/ NMP as solvent.
.sup.++These three samples (Samples 4-6) are blends of multiple
runs, made according to Examples 1, 3, and 4, respectively MEK =
methyl ethyl ketone, MPK = methyl propyl ketone, MAK = methyl amyl
ketone, PM acetate = propylene glycol methyl acetate, EB acetate =
ethylene glycol butyl acetate, PM = propylene glycol monomethyl
ether, DM = diethylene glycol methyl ether, PB = propylene glycol
monobutyl ether, DE = diethylene glycol ethyl ether, PP = propylene
glycol monopropyl ether, Eastman EP Solvent = ethylene glycol
monopropyl ether, Eastman EB Solvent = ethylene glycol monobutyl
ether, 95% Tecsol C = ethanol with methanol, MIBK and ethyl acetate
as denaturants with 5% water, NMP = n-methyl pyrrolidone, Eastman
EEP Solvent = ethyl 3-ethoxypropionate
TABLE-US-00005 TABLE 5 Solubility of Cellulose Esters Comparative
Comparative Comparative Solubility at 10 wt % solutions Example 28
Example 31 Example 29 Example 32 Example 30 Example 33 Esters---
HS-CAB-38 CAB 381-0.1 HS-CAB-55 CAB 551-0.01 HS-CAB-17 CAB 171-15S
Sample 1, Table 4 Sample 2, Sample 3, Table 4 Table 4 Solvent:
Blends: Toluene/Ethyl Acetate 70/30 9 9 9 9 5 1 Toluene/95% Tecsol
C 80/20 9 9 9 9 5 1 Tecsol C(95)/Ethyl Acetate 70/30 9 9 9 9 7 1
Isopropyl Alcohol/Water 90/10 9 1 9 1 1 1 MEK/MPK/MAK/EEP/n-Butyl 9
9 9 9 9 9 Acetate 20/20/10/15/35 Ketones: Acetone 9 9 9 9 9 9 MEK 9
9 9 9 9 9 MPK 9 9 9 9 8 9 MAK 9 9 9 9 5 1 C-11 ketone 9 1 9 9 3 1
DIBK 9 1 9 9 1 1 Esters: Ethyl Acetate 9 9 9 9 9 9 n-Butyl
Propionate 9 9 9 9 1 1 PM Acetate 9 9 9 9 9 3 EB Acetate 9 9 9 9 7
1 n-Butyl Acetate 9 9 9 9 7 1 t-Butyl Acetate (ester solvent) 9 9 9
9 3 1 n-Propyl Propionate 9 9 9 9 7 9 1 = insoluble, 3 = partially
soluble, 5 = gels, 7 = soluble hazy, 9 = soluble
TABLE-US-00006 TABLE 6 Solubility of Cellulose Esters Comparative
Comparative Comparative Solubility at 10 wt % solutions Example 28
Example 31 Example 29 Example 32 Example 30 Example 33 Esters---
HS-CAB-38 CAB 381-0.1 HS-CAB-55 CAB 551-0.01 HS-CAB-17 CAB 171-15S
Sample 1, Table 4 Sample 2, Table 4 Sample 3, Table 4 Solvent:
Glycol ethers: PM 9 9 9 9 9 1 DM 9 9 9 9 9 3 PB 7 1 7 9 3 1 DE 9 9
9 9 8 1 PP 9 1 9 9 5 1 EP 9 1 9 9 5 1 EB 9 1 9 9 3 1 Alcohols:
Diacetone alcohol 9 9 9 9 9 9 Methanol 9 1 9 1 1 1 Tecsol C (95) 9
1 9 1 3 1 Isopropyl alcohol 3 1 7 1 3 1 Other: EEP 9 9 9 9 7 1
Exxate 600 9 9 9 9 5 1 NMP 9 9 5 9 9 9 VM & P Naptha 3 1 3 1 3
1 Toluene 9 1 9 5 3 1 Xylene 3 1 3 1 3 1 Dimethylaminoethanol 9 9 9
9 9 9 Methylene chloride 9 9 9 9 9 9 Pyridine 9 9 9 9 9 9 1 =
insoluble, 3 = partially soluble, 5 = gels, 7 = soluble hazy, 9 =
soluble
Example 34
Viscosity Studies
[0206] The viscosities of an HS-CAB-38 (Sample 4, Table 4) and an
HS-CAB-55 (Sample 5, Table 4) are compared to the lowest viscosity
commercial cellulose esters, CAB-381-0.1 and CAB-551-0.01, of
comparable butyryl content, using as solvent an n-butyl
acetate/xylene in a 90/10 by weight mixture, using Brookfield
viscosity as a function of concentration. FIG. 1 shows the relative
viscosity at each measured concentration. Note how the log
viscosities vs. concentration plots are parallel for each of the
esters. This indicates that each of the esters has a similar
exponential viscosity rise with concentration, except that the
lower the molecular weight of the ester is, the higher the
concentration becomes to display the same behavior. Because the
inventive esters exhibit a lower viscosity than conventional esters
at the same concentration, they allow coating formulations having a
higher ester content at the target viscosity.
[0207] Additional Brookfield viscosity data are presented in Table
6A. The HS-CAB's evaluated are dissolved at various solids levels
in n-butyl acetate/xylene (9:1 by weight).
TABLE-US-00007 TABLE 6A Viscosity in a 90/10 by weight mixture of
n-butyl acetate/xylene Material lot Wt % Bu Wt % OH IV (PM95) %
Solids Centipoise HS-CAB-38 EMT02-121 39.77 1.61 0.09 30 12.2
HS-CAB-38 EMT02-121 39.77 1.61 0.09 50 312 HS-CAB-38 EMT02-121
39.77 1.61 0.09 60 3430 HS-CAB-38 EMT02-121 39.77 1.61 0.09 70
70800 HS-CAB-38 EMT02-122 38.48 1.66 0.08 30 12.6 HS-CAB-38
EMT02-122 38.48 1.66 0.08 50 332 HS-CAB-38 EMT02-122 38.48 1.66
0.08 60 3655 HS-CAB-38 EMT02-122 38.48 1.66 0.08 70 88300 HS-CAB-55
EMT02-117 52.78 1.18 0.08 30 9.4 HS-CAB-55 EMT02-117 52.78 1.18
0.08 50 139.4 HS-CAB-55 EMT02-117 52.78 1.18 0.08 60 200000*
HS-CAB-55 EMT02-117 52.78 1.18 0.08 70 200000* HS-CAB-55 EMT02-128
54.17 1.43 0.08 30 12.3 HS-CAB-55 EMT02-128 54.17 1.43 0.08 50
132.4 HS-CAB-55 EMT02-128 54.17 1.43 0.08 60 885 HS-CAB-55
EMT02-128 54.17 1.43 0.08 70 200000* HS-CAB-17 EMT02-084 20.1 2.18
0.08 30 37.6 HS-CAB-17 EMT02-084 20.1 2.18 0.08 50 2685 HS-CAB-17
EMT02-084 20.1 2.18 0.08 60 65800 HS-CAB-17 EMT02-084 20.1 2.18
0.08 70 200000 HS-CAB-17 EMT02-085 20.1 2.18 0.08 30 45.5 HS-CAB-17
EMT02-085 20.42 1.99 0.09 50 5660 HS-CAB-17 EMT02-085 20.42 1.99
0.09 60 124800 HS-CAB-17 EMT02-085 20.42 1.99 0.09 70 **
CAB-551-0.01 NA 55.06 1.50 0.26 10 3.8 CAB-551-0.01 NA 55.06 1.50
0.26 30 160 CAB-551-0.01 NA 55.06 1.50 0.26 40 935 CAB-551-0.01 NA
55.06 1.50 0.26 50 10300 CAB-381-0.1 NA 39.87 1.61 0.44 10 38
CAB-381-0.1 NA 39.87 1.61 0.44 30 1600 CAB-381-0.1 NA 39.87 1.61
0.44 40 15300 CAB-381-0.1 NA 39.87 1.61 0.44 50 508000 HS-CAB-55
(EMT02-117) gels at 65, 67, 69, and 70% HS-CAB-55 (EMT02-128) gels
at 70% HS-CAB-17 (EMT02-084) gels at 70% HS-CAB-17 (EMT02-085) gels
at 60% and 70% HS-CAB-38 (EMT02-121) is very viscous at 70%
HS-CAB-38 (EMT02-122) is very viscous at 70% HS-CAB-17 (EMT02-084)
is very viscous at 60% *Mixture gels ** Not measured since material
is partially insoluble
Examples 35-40 and Comparative Examples 41-46
Viscosity of HS CAB/Resin Blends and Comparison with Conventional
CAB/Resin Blends
[0208] Blends of HS-CAB-38 (Sample 1, Table 4) and HS-CAB-55
(Sample 2, Table 4) with commercial resins (Duramac HS 2706,
Polymac HS 5776, and Acrylamac 232-1700) (1:1 CAB to resin, at 20%
and 40% solids levels) are prepared and the viscosities of the
solutions are determined using a Brookfield viscometer. Comparison
blends of CAB-381-0.1 and CAB-551-0.01 with commercial resins
(Duramac HS 2706, Polymac HS 5776, and Acrylamac 232-1700) (1:1 CAB
to resin, at 20% solids levels) are prepared and the viscosities of
the solutions are determined using a Brookfield viscometer. The
results are presented in Table 7. The HS-CABs have very little
impact on solution or spray viscosity and can thus be added at much
higher levels than conventional esters. This results in an increase
in the % non-volatiles in the system.
TABLE-US-00008 TABLE 7 Viscosity of CABs for High DS.sub.Max, low
DP and Conventional CAB/Resin Blends Example # CAB Type Resin Type
Ratio of CAB:Resin Total Solids Spindle # RPM Viscosity (cP) 35
HS-CAB-38 Duramac HS 2706 1:1 40% 18 30 13.3 41 CAB-381-0.1 Duramac
HS 2706 1:1 20% 18 30 23.7 36 HS-CAB-55 Duramac HS 2706 1:1 40% 18
30 12.8 42 CAB-551-0.01 Duramac HS 2706 1:1 20% 18 60 6.0 37
HS-CAB-38 Polymac HS 5776 1:1 40% 18 30 15.4 43 CAB-381-0.1 Polymac
HS 5776 1:1 20% 18 30 24.5 38 HS-CAB-55 Polymac HS 5776 1:1 40% 18
30 13.9 44 CAB-551-0.01 Polymac HS 5776 1:1 20% 18 60 5.9 39
HS-CAB-38 Acrylamac 232-1700 1:1 40% 18 30 37.4 45 CAB-381-0.1
Acrylamac 232-1700 1:1 20% 18 30 31.9 40 HS-CAB-55 Acrylamac
232-1700 1:1 40% 18 30 32.9 46 CAB-551-0.01 Acrylamac 232-1700 1:1
20% 18 60 8.4
Example 47
Compatibility of HS-CAB's with Various Coatings Resins
[0209] Solutions are prepared using ratios of cellulosic to
modifying resin of 1/9, 1/3, 1/1, and 3/1 at 10% solids in a
mixture of n-butyl acetate/MEK/MPK/EEP/MAK (35/20/20/15/10). Films
are cast on glass at 10 mil thickness. The films are allowed to air
dry for 24 hours. The resulting films are evaluated visually under
good room lights (Tables 8 and 9) for film clarity. HS-CAB-55
(Sample 2, Table 4) and HS-CAB-38 (Sample 1, Table 4) have good
compatibility with most resins tested: acrylics, polyesters,
melamine type resins, urea formaldehyde resins, alkyds, isocyanate
resin, phenolics and epoxies, and limited compatibility in vinyls
and polyamides. HS-CAB-17s (Sample 3, Table 4) are less compatible
than HS-CAB-55 and HS-CAB-38, but still can be used with the resins
tested in limited amounts.
[0210] This example shows the compatibility of the inventive
cellulose mixed esters with a variety of coatings resins.
TABLE-US-00009 TABLE 8 Compatibility Studies HS-CAB-55 HS-CAB-38
HS-CAB-20 Sample: TYPE RESIN EMT02-82 EMT02-83 EMT02-85 R&H
Acryloid AT954 1:4 THERMOSET 0 0 1 ACRYLIC 1:1 0 0 9 4:1 0 0 7
R&H Acryloid B-44 1:4 ACRYLIC 0 0 9 LACQUER 1:1 0 7 7 4:1 0 0 0
R&H Paraloid A-21 1:4 ACRYLIC 0 0 0 LACQUER 1:1 0 0 9 4:1 0 0 7
Cytec CYMEL 303 1:4 HEXAMETHOXY- 0 0 0 METHYL MELAMINE 1:1 0 0 7
4:1 0 0 7 ELVACITE 2008 1:4 DUPONT ACRYLIC 0 0 0 LACQUER 1:1 Methyl
methacrylate 0 0 7 (lo MW) 4:1 0 0 7 Polymac HS220-2010 1:4
Polyester 0 0 0 1:1 0 0 0 4:1 0 0 0 BEETLE 65 1:4 Cytec Urea 0 7 0
Formadehyde 1:1 0 0 0 4:1 7 7 0 UCAR VYHD 1:4 VINYL 3 9 9
CHLORIDE/VINYL ACETATE 1:1 3 9 9 4:1 3 7 1 CK-2103 1:4 UC PHENOLIC
0 0 0 1:1 0 0 0 4:1 0 0 0 R&H Paraloid WR97 1:4 RH WATER 0 0 7
REDUCIBLE TS ACRYLIC 1:1 0 0 9 4:1 0 0 7 Film Compatibility, 1 mil
films cast from 10 mil thickness from 10% solution from a solvent
blend of MEK/MPK/MAK/EEP/n-BuOAc (20/20/10/15/35) 0 = clear, no
haze; 1 = very slight haze, only in bright light; 3 = slight haze
in room; 5 = translucent; 7 = translucent and incompatible domains;
9 = hazy and incompatible; 10 = opaque
TABLE-US-00010 TABLE 9 Compatibility Studies HS-CAB-55 HS-CAB-38
HS-CAB-20 Sample: TYPE RESIN EMT02-82 EMT02-83 EMT02-85 Neat esters
1:0 Cellulosic resins without 0 0 0 resins R&H Acryloid AU608X
R& H Acrylic 0 0 0 1:4 1:1 0 0 1 4:1 0 0 7 EPON 1001F 1:4
DUPONT EPOXY 5 5 5 1:1 5 5 9 4:1 3 5 7 VERSAMID 750 1:4 POLYAMIDE 9
9 9 1:1 9 9 9 4:1 9 9 9 Duramac 207-2706 1:4 EASTMAN short oil, 0 0
0 TOFA, 23% n-butac, corrosion resistant 1:1 0 0 0 4:1 0 0 0
Duramac 5205 1:4 Med. Coconut oil alkyd, 0 0 1 40% xylene.
Plasticizer for NC 1:1 0 0 7 4:1 0 0 7 Duramac 51-5135 1:4 EASTMAN
Med oil SOYA 0 5 7 alkyd gasoline resistant, 40% VMP 1:1 0 3 7 4:1
0 3 7 Duramac 207-1405 1:4 EASTMAN SOYA chain 1 5 7 stopped alkyd,
50% NV 1:1 1 3 7 4:1 0 1 7 ELVACITE 2044 1:4 DuPont ethyl
methacrylate 0 0 7 1:1 0 0 8 4:1 0 0 8 Des N 3300 1:4 Bayer
Polymeric isocyanate 0 0 0 1:1 0 0 5 4:1 0 0 10
Example 48
HS-CAB Solubilities
[0211] Solutions are prepared using ratios of cellulosic to
modifying resin ratio of 1/1 at 10% solids in one of four solvent
blends, Solvent 1 (MEK/PMAc/EEP, 5/4/1), Solvent 2 (MEK/Xylene/EEP,
5/4/1), Solvent 3 (MEK/PMAc/Toluene, 1/1/2), Solvent 4
(PMAc/EtOH/n-BuOH, 2/1/1). Films are cast on glass at 10 mil
thickness. The films are allowed to air dry for 24 hours. The
resulting films are evaluated visually under good room lights and
the results are presented in Tables 10-16 for film clarity.
TABLE-US-00011 TABLE 10 Film Compatibility 1 mil films cast from 8
mil thickness from 25% solution from 4 different solvent blends
Resin Eastman Eastman R&H Acryloid R&H Acrylamac Acrylamac
AT400 Bayer A670 AU608 2328 2350 CAB:Resin 1:1 1:1 1:1 1:1 1:1
Solvent Solvent 1 Solvent 1 Solvent 1 Solvent 1 Solvent 1 Type
Resin OH OH Wt % Thermoset Functional Functional Thermoset OH
Functional Wt % Bu Wt % Ac OH Acrylic-1 Acrylic-1 Acrylic-1
Acrylic-1 Acrylic-1 CAB 381- Commercial 39.87* 12.90* 1.61* 0 0 0 1
0 0.1 CAB 551- Commercial 55.06* 1.07* 1.50* 0 0 0 0 0 0.01
HS-CAB-38 EMT02-158 39.51 11.21 2.16 0 0 0 0 3 HS-CAB-38 EMT03-030
35.01 13.42 3.51 3 0 0 3 5 HS-CAB-38 EMT02-162 39.73 11.5 1.13 0 0
0 0 3 HS-CAB-55 EMT02-105 53.88 2.52 1.09 0 0 0 0 0 HS-CAB-55
EMT02-117 54.1 2.21 1.19 0 0 0 0 0 HS-CAB-55 EMT02-131 54.59 2.36
3.1 0 0 0 1 0 HS-CAB-55 EMT02-133 51.82 2.85 2.49 0 0 0 0 0
HS-CAB-55 EMT02-169 45.39 3.56 4.61 0 0 0 0 5 HS-CAB-46 EMT03-077
47.36 6.44 2.23 0 0 0 0 0 HS-CAB-46 EMT02-062 44.18 7.24 3.1 0 0 0
0 1 HS-CAB-29 EMT03-059 28.72 17.17 3.83 5 3 0 9 9 HS-CAB-29
EMT03-051 29.38 18.37 1.81 1 1 0 9 9 HS-CAB-20 EMT03-042 21.71
23.93 1.32 9 9 5 9 9 HS-CAB-20 EMT03-039 24.25 21.12 2.31 9 7 0 5 9
HS-CAB-20 EMT03-044 22.87 27.45 0.81 9 7 7 9 9 HS-CAB-20 EMT03-040
23.99 21.43 3.23 9 7 0 5 9 Solvent 1 = MEK/PMAc/EEP 5/4/1 Solvent 2
= MEK/Xylene/EEP 5/4/1 Solvent 3 = MEK/PMAc/Toluene 1/1/2 Solvent 4
= PMAc/EtOH/n-BuOH 2/1/1 0 = clear no haze; 1 = very slight have,
only in bright light; 3 = slight haze in room; 5 = translucent; 7 =
translucent and incompatible domains; 9 = hazy and incompatible; 10
= opaque *Calculated using equations previously described in
Examples 1-8.
TABLE-US-00012 TABLE 11 Film Compatibility 1 mil films cast from 8
mil thickness from 25% solution from 4 different solvent blends
Resin Eastman Akzo Nobel Eastman Eastman Eastman Reactol 175
Microgel Duramac 1205 Duramac 2706 Duramac 2314 CAB:Resin 1:1 1:1
1:1 1:1 1:1 Solvent Solvent 1 Solvent 1 Solvent 1 Solvent 1 Solvent
1 Type Resin Chain Stopped Hexamethoxy Wt % Wt % Wt % Thermoset
Thermoset SOYA Oil methyl Styrenated Bu Ac OH Acrylic-1 Acrylic-1
alkyd-1 melamine-1 alkyd-1 CAB 381- Commercial 39.87* 12.90* 1.61*
0 7 1 0 3 0.1 CAB 551- Commercial 55.06* 1.07* 1.50* 0 5 3 0 0 0.01
HS-CAB-38 EMT02-158 39.51 11.21 2.16 0 0 1 0 0 HS-CAB-38 EMT03-030
35.01 13.42 3.51 0 1 3 0 9 HS-CAB-38 EMT02-162 39.73 11.5 1.13 0 0
3 0 0 HS-CAB-55 EMT02-105 53.88 2.52 1.09 0 0 1 0 0 HS-CAB-55
EMT02-117 54.1 2.21 1.19 0 0 3 0 0 HS-CAB-55 EMT02-131 54.59 2.36
3.1 0 0 0 0 0 HS-CAB-55 EMT02-133 51.82 2.85 2.49 0 0 0 0 0
HS-CAB-55 EMT02-169 45.39 3.56 4.61 0 1 1 0 1 HS-CAB-46 EMT03-077
47.36 6.44 2.23 0 0 0 0 0 HS-CAB-46 EMT02-062 44.18 7.24 3.1 0 0 0
0 0 HS-CAB-29 EMT03-059 28.72 17.17 3.83 0 3 3 0 9 HS-CAB-29
EMT03-051 29.38 18.37 1.81 0 1 5 0 9 HS-CAB-20 EMT03-042 21.71
23.93 1.32 0 3 9 9 9 HS-CAB-20 EMT03-039 24.25 21.12 2.31 0 3 9 9 9
HS-CAB-20 EMT03-044 22.87 27.45 0.81 7 3 9 1 9 HS-CAB-20 EMT03-040
23.99 21.43 3.23 0 3 9 0 9 Solvent 1 = MEK/PMAc/EEP 5/4/1 Solvent 2
= MEK/Xylene/EEP 5/4/1 Solvent 3 = MEK/PMAc/Toluene 1/1/2 Solvent 4
= PMAc/EtOH/n-BuOH 2/1/1 0 = clear no haze; 1 = very slight have,
only in bright light; 3 = slight haze in room; 5 = translucent; 7 =
translucent and incompatible domains; 9 = hazy and incompatible; 10
= opaque
TABLE-US-00013 TABLE 12 Film Compatibility 1 mil films cast from 8
mil thickness from 25% solution from 4 different solvent blends
Resin Bayer Cytec Resimene Resimene Desmophen Desmodur Cymel
CE-7103 755 1800 3300 303 CAB:Resin 1:1 1:1 1:1 1:1 1:1 Solvent
Solvent 1 Solvent 1 Solvent 2 Solvent 2 Solvent 2 Wt % Wt % Wt %
Type Resin Bu Ac OH Melamine-1 Melamine-1 Polyester-2 Isocyanate-2
Melamine-2 CAB 381- Commercial 39.87* 12.90* 1.61* 0 0 0 5 0 0.1
CAB 551- Commercial 55.06* 1.07* 1.50* 0 0 0 0 0 0.01 HS-CAB-38
EMT02-158 39.51 11.21 2.16 0 0 0 0 0 HS-CAB-38 EMT03-030 35.01
13.42 3.51 0 0 0 1 0 HS-CAB-38 EMT02-162 39.73 11.5 1.13 0 0 0 0 0
HS-CAB-55 EMT02-105 53.88 2.52 1.09 0 0 0 0 0 HS-CAB-55 EMT02-117
54.1 2.21 1.19 0 0 0 0 0 HS-CAB-55 EMT02-131 54.59 2.36 3.1 0 0 0 0
0 HS-CAB-55 EMT02-133 51.82 2.85 2.49 0 0 0 0 0 HS-CAB-55 EMT02-169
45.39 3.56 4.61 0 0 0 1 0 HS-CAB-46 EMT03-077 47.36 6.44 2.23 0 0 0
0 0 HS-CAB-46 EMT02-062 44.18 7.24 3.1 0 0 0 0 0 HS-CAB-29
EMT03-059 28.72 17.17 3.83 3 0 0 9 0 HS-CAB-29 EMT03-051 29.38
18.37 1.81 0 0 0 0 0 HS-CAB-20 EMT03-042 21.71 23.93 1.32 9 9 7 7 0
HS-CAB-20 EMT03-039 24.25 21.12 2.31 1 0 0 9 0 HS-CAB-20 EMT03-044
22.87 27.45 0.81 5 0 7 1 0 HS-CAB-20 EMT03-040 23.99 21.43 3.23 5 0
7 9 0 Solvent 1 = MEK/PMAc/EEP 5/4/1 Solvent 2 = MEK/Xylene/EEP
5/4/1 Solvent 3 = MEK/PMAc/Toluene 1/1/2 Solvent 4 =
PMAc/EtOH/n-BuOH 2/1/1 0 = clear no haze; 1 = very slight have,
only in bright light; 3 = slight haze in room; 5 = translucent; 7 =
translucent and incompatible domains; 9 = hazy and incompatible; 10
= opaque
TABLE-US-00014 TABLE 13 Film Compatibility 1 mil films cast from 8
mil thickness from 25% solution from 4 different solvent blends
Resin Eastman Eastman Eastman Eastman Polymac HS Polymac HS Duramac
Duramac 5789 5761 5135 5731 CAB:Resin 1:1 1:1 1:1 1:1 Solvent
Solvent 2 Solvent 2 Solvent 2 Solvent 2 Type Resin Medium Medium
SOYA oil SOYA oil Wt % Bu Wt % Ac Wt % OH Polyester-2 Polyester-2
alkyd-2 alkyd-2 CAB 381-0.1 Commercial 39.87* 12.90* 1.61* 0 0 0 5
CAB 551-0.01 Commercial 55.06* 1.07* 1.50* 0 0 1 3 HS-CAB-38
EMT02-158 39.51 11.21 2.16 0 0 7 3 HS-CAB-38 EMT03-030 35.01 13.42
3.51 0 0 9 7 HS-CAB-38 EMT02-162 39.73 11.5 1.13 0 0 7 3 HS-CAB-55
EMT02-105 53.88 2.52 1.09 0 0 0 0 HS-CAB-55 EMT02-117 54.1 2.21
1.19 0 0 0 0 HS-CAB-55 EMT02-131 54.59 2.36 3.1 0 0 7 3 HS-CAB-55
EMT02-133 51.82 2.85 2.49 0 0 0 3 HS-CAB-55 EMT02-169 45.39 3.56
4.61 0 0 9 9 HS-CAB-46 EMT03-077 47.36 6.44 2.23 0 0 1 3 HS-CAB-46
EMT02-062 44.18 7.24 3.1 0 0 7 9 HS-CAB-29 EMT03-059 28.72 17.17
3.83 0 0 9 9 HS-CAB-29 EMT03-051 29.38 18.37 1.81 0 0 7 7 HS-CAB-20
EMT03-042 21.71 23.93 1.32 9 9 9 9 HS-CAB-20 EMT03-039 24.25 21.12
2.31 0 0 9 7 HS-CAB-20 EMT03-044 22.87 27.45 0.81 9 9 7 7 HS-CAB-20
EMT03-040 23.99 21.43 3.23 0 0 9 9 Solvent 1 = MEK/PMAc/EEP 5/4/1
Solvent 2 = MEK/Xylene/EEP 5/4/1 Solvent 3 = MEK/PMAc/Toluene 1/1/2
Solvent 4 = PMAc/EtOH/n-BuOH 2/1/1 0 = clear no haze; 1 = very
slight have, only in bright light; 3 = slight haze in room; 5 =
translucent; 7 = translucent and incompatible domains; 9 = hazy and
incompatible; 10 = opaque
TABLE-US-00015 TABLE 14 Film Compatibility 1 mil films cast from 8
mil thickness from 25% solution from 4 different solvent blends
Resin Eastman Shell Dow Bayer Duramac Epon DER Rhodia Desmodur 5359
1001F 542 XIDT IL CAB:Resin 1:1 1:1 1:1 1:1 1:1 Solvent Solvent 2
Solvent 2 Solvent 2 Solvent 2 Solvent 2 Type Resin Wt % Wt %
Styrenated Bu Wt % Ac OH alkyd-2 Epoxy-2 Epoxy-2 Isocyanate-2
Isocyanate-2 CAB 381-0.1 Commercial 39.87* 12.90* 1.61* 9 5 0 3 9
CAB 551-0.01 Commercial 55.06* 1.07* 1.50* 0 0 0 0 10 HS-CAB-38
EMT02-158 39.51 11.21 2.16 3 5 0 0 0 HS-CAB-38 EMT03-030 35.01
13.42 3.51 9 5 0 5 0 HS-CAB-38 EMT02-162 39.73 11.5 1.13 3 5 0 0 0
HS-CAB-55 EMT02-105 53.88 2.52 1.09 0 5 0 0 9 HS-CAB-55 EMT02-117
54.1 2.21 1.19 0 5 0 0 9 HS-CAB-55 EMT02-131 54.59 2.36 3.1 3 5 0 0
0 HS-CAB-55 EMT02-133 51.82 2.85 2.49 0 3 0 0 3 HS-CAB-55 EMT02-169
45.39 3.56 4.61 9 3 0 3 0 HS-CAB-46 EMT03-077 47.36 6.44 2.23 0 3 0
0 0 HS-CAB-46 EMT02-062 44.18 7.24 3.1 7 3 0 0 0 HS-CAB-29
EMT03-059 28.72 17.17 3.83 9 9 3 9 0 HS-CAB-29 EMT03-051 29.38
18.37 1.81 7 5 0 3 0 HS-CAB-20 EMT03-042 21.71 23.93 1.32 9 7 0 9 0
HS-CAB-20 EMT03-039 24.25 21.12 2.31 9 3 0 9 0 HS-CAB-20 EMT03-044
22.87 27.45 0.81 9 7 0 9 0 HS-CAB-20 EMT03-040 23.99 21.43 3.23 9 7
0 9 0 Solvent 1 = MEK/PMAc/EEP 5/4/1 Solvent 2 = MEK/Xylene/EEP
5/4/1 Solvent 3 = MEK/PMAc/Toluene 1/1/2 Solvent 4 =
PMAc/EtOH/n-BuOH 2/1/1 0 = clear no haze; 1 = very slight have,
only in bright light; 3 = slight haze in room; 5 = translucent; 7 =
translucent and incompatible domains; 9 = hazy and incompatible; 10
= opaque
TABLE-US-00016 TABLE 15 Film Compatibility 1 mil films cast from 8
mil thickness from 25% solution from 4 different solvent blends
Resin Eastman Carbamac UCC UCAR HS4372 VYHD UCAR VMCH CAB:Resin 1:1
1:1 1:1 Solvent Solvent 2 Solvent 3 Solvent 3 Type Resin Vinyl
Vinyl Wt % Wt % Wt % chloride/Vinyl chloride/Vinyl Bu Ac OH
Polyurethane-2 acetate-3 acetate-3 CAB 381- Commercial 39.87*
12.90* 1.61* 7 0.1 CAB 551- Commercial 55.06* 1.07* 1.50* 9 0.01
HS-CAB-38 EMT02-158 39.51 11.21 2.16 1 7 7 HS-CAB-38 EMT03-030
35.01 13.42 3.51 5 7 7 HS-CAB-38 EMT02-162 39.73 11.5 1.13 3 7 3
HS-CAB-55 EMT02-105 53.88 2.52 1.09 1 7 3 HS-CAB-55 EMT02-117 54.1
2.21 1.19 3 7 7 HS-CAB-55 EMT02-131 54.59 2.36 3.1 5 7 7 HS-CAB-55
EMT02-133 51.82 2.85 2.49 3 7 3 HS-CAB-55 EMT02-169 45.39 3.56 4.61
7 7 7 HS-CAB-46 EMT03-077 47.36 6.44 2.23 3 7 3 HS-CAB-46 EMT02-062
44.18 7.24 3.1 7 7 7 HS-CAB-29 EMT03-059 28.72 17.17 3.83 5 7 3
HS-CAB-29 EMT03-051 29.38 18.37 1.81 7 7 3 HS-CAB-20 EMT03-042
21.71 23.93 1.32 7 7 3 HS-CAB-20 EMT03-039 24.25 21.12 2.31 7 7 3
HS-CAB-20 EMT03-044 22.87 27.45 0.81 7 3 3 HS-CAB-20 EMT03-040
23.99 21.43 3.23 7 7 3 Solvent 1 = MEK/PMAc/EEP 5/4/1 Solvent 2 =
MEK/Xylene/EEP 5/4/1 Solvent 3 = MEK/PMAc/Toluene 1/1/2 Solvent 4 =
PMAc/EtOH/n-BuOH 2/1/1 0 = clear no haze; 1 = very slight have,
only in bright light; 3 = slight haze in room; 5 = translucent; 7 =
translucent and incompatible domains; 9 = hazy and incompatible; 10
= opaque
TABLE-US-00017 TABLE 16 Film Compatibility 1 mil films cast from 8
mil thickness from 25% solution from 4 different solvent blends
Resin DuPont Henkle LVAX Verasmid 40 750 CAB:Resin 1:1 1:1 Solvent
Solvent 3 Solvent 4 Type Resin Vinyl Wt % chloride/Vinyl Wt % Bu Wt
% Ac OH acetate-3 Polyamide-4 CAB 381-0.1 Commercial 39.87* 12.90*
1.61* CAB 551-0.01 Commercial 55.06* 1.07* 1.50* HS-CAB-38
EMT02-158 39.51 11.21 2.16 3 5 HS-CAB-38 EMT03-030 35.01 13.42 3.51
7 5 HS-CAB-38 EMT02-162 39.73 11.5 1.13 3 3 HS-CAB-55 EMT02-105
53.88 2.52 1.09 5 3 HS-CAB-55 EMT02-117 54.1 2.21 1.19 5 5
HS-CAB-55 EMT02-131 54.59 2.36 3.1 5 5 HS-CAB-55 EMT02-133 51.82
2.85 2.49 5 5 HS-CAB-55 EMT02-169 45.39 3.56 4.61 3 5 HS-CAB-46
EMT03-077 47.36 6.44 2.23 5 5 HS-CAB-46 EMT02-062 44.18 7.24 3.1 5
3 HS-CAB-29 EMT03-059 28.72 17.17 3.83 5 5 HS-CAB-29 EMT03-051
29.38 18.37 1.81 5 5 HS-CAB-20 EMT03-042 21.71 23.93 1.32 5 5
HS-CAB-20 EMT03-039 24.25 21.12 2.31 5 5 HS-CAB-20 EMT03-044 22.87
27.45 0.81 5 7 HS-CAB-20 EMT03-040 23.99 21.43 3.23 5 3 Solvent 1 =
MEK/PMAc/EEP 5/4/1 Solvent 2 = MEK/Xylene/EEP 5/4/1 Solvent 3 =
MEK/PMAc/Toluene 1/1/2 Solvent 4 = PMAc/EtOH/n-BuOH 2/1/1 0 = clear
no haze; 1 = very slight have, only in bright light; 3 = slight
haze in room; 5 = translucent; 7 = translucent and incompatible
domains; 9 = hazy and incompatible; 10 = opaque
Example 49
Solubility of Various HS-CAB's
[0212] The HS-CAB's described in Tables 2-3 (Examples 1-27) are
treated with solvents and solvent blends (0.2 g of ester in 1.8 g
of solvent) to prepare 10 wt % solutions of the CAB's and
conventional CAB's (CAB-381-0.1 and CAB-551-0.01). The samples are
placed on a roller overnight to allow them to go into solution.
Samples are removed from the roller and the solubility of each
HS-CAB in each solvent or solvent blend is determined according to
the following criteria:
[0213] 1=Insoluble; 3=Partially Soluble; 5=Gels; 7=Soluble, Hazy;
9=Soluble, Clear. The results of the solubility studies are
presented in Tables 17-19.
TABLE-US-00018 TABLE 17 CAB CAB CAB EMT02-105 EMT2-158 EMT03-030
EMT02-117 EMT02-162 EMT02-131 171-15S 381-0.1 551-0.01 HS-CAB-55
HS-CAB-38 HS-CAB-38 HS-CAB-55 HS-CAB-38 HS-CAB-55 Wt % Bu 53.88
39.51 35.01 54.1 39.73 54.59 Wt % Ac 2.52 11.21 13.42 2.21 11.5
2.36 Wt % OH 1.09 2.16 3.51 1.19 1.13 3.1 Isopropyl 1 1 1 1 3 9 1 1
9 alcohol/water 90/10 C-11 ketone 1 1 9 9 9 3 9 5 5 DIBK 1 1 9 9 7
3 9 9 9 PP 1 1 9 9 9 9 9 9 9 EP 1 1 9 9 9 9 9 9 9 EB 1 1 9 9 9 9 9
7 9 MeOH 1 1 1 1 9 9 3 3 9 Tescol C 1 1 1 3 1 3 3 1 9 (95) Toluene
1 1 5 9 9 3 9 9 9 Xylene 1 1 1 1 1 1 1 1 1
TABLE-US-00019 TABLE 18 CAB CAB CAB EMT03-042 EMT03-059 EMT03-077
EMT03-051 EMT02-133 171-15S 381-0.1 551-0.01 HS-CAB-20 HS-CAB-29
HS-CAB-46 HS-CAB-29 HS-CAB-55 Wt % Bu 21.71 28.72 47.36 29.38 51.82
Wt % Ac 23.93 17.17 6.44 18.37 2.85 Wt % OH 1.32 3.83 2.23 1.81
2.49 Isopropyl 1 1 1 1 3 9 1 9 alcohol/water 90/10 C-11 ketone 1 1
9 1 1 9 1 9.1 DIBK 1 1 9 1 1 9 1 .1 PP 1 1 9 5 5 9 7 9.9 EP 1 1 9 9
1 9 9 9.9 EB 1 1 9 3 9 9 3 9.9 MeOH 1 1 1 1 9 9 1 9.9 Tescol C 1 1
1 1 1 9 1 9.9 (95) Toluene 1 1 5 3 1 9 1 9.1 Xylene 1 1 1 1 1 1 1
1.1
TABLE-US-00020 TABLE 19 CAB CAB CAB EMT03-039 EMT03-044 EMT02-169
EMT03-062 EMT03-040 171-15S 381-0.1 551-0.01 HS-CAB-20 HS-CAB-20
HS-CAB-55 HS-CAB-46 HS-CAB-20 Wt % Bu 24.25 22.87 45.39 44.18 23.99
Wt % Ac 21.12 27.45 3.56 7.24 21.43 Wt % OH 2.31 0.81 4.61 3.1 3.23
Isopropyl 1 1 1 1 1 9 9 1 alcohol/water 90/10 C-11 ketone 1 1 9 1 1
9 5 1 DIBK 1 1 9 1 1 3 3 1 PP 1 1 9 5 7 9 9 5 EP 1 1 9 9 1 9 9 9 EB
1 1 9 3 3 9 9 3 MeOH 1 1 1 1 1 9 9 1 Tescol C (95) 1 1 1 1 1 9 9 1
Toluene 1 1 5 3 3 3 3 3 Xylene 1 1 1 1 1 3 1 1 Esters EMT02-105
EMT2-158 EMT03-030 EMT02-117 EMT02-162 EMT02-131 EMT03-042
HS-CAB-55 HS-CAB-38 HS-CAB-38 HS-CAB-55 HS-CAB-38 HS-CAB-55
HS-CAB-20 Isopropyl alcohol/water 1 3 9 1 1 9 1 90/10 C-11 ketone 9
9 3 9 5 5 1 DIBK 9 7 3 9 9 9 1 PP 9 9 9 9 9 9 5 EP 9 9 9 9 9 9 9 EB
9 9 9 9 7 9 3 MeOH 1 9 9 3 3 9 1 Tescol C (95) 3 1 3 3 1 9 1
Toluene 9 9 3 9 9 9 3 Xylene 1 1 1 1 1 1 1 n-butyl acetate 9 9 9 9
9 9 7 Ethyl acetate 9 9 7 9 9 9 7 Texanol 9 9 9 9 9 9 3 2-EH
acetate 9 9 3 9 9 9 1 EEP 9 9 7 9 9 9 7 PM 9 9 9 9 9 9 7 PB 9 9 9 9
9 9 7 PM acetate 9 9 9 9 9 9 7 EB acetate 9 9 9 9 9 9 7 MPK 9 9 7 9
9 9 7 MEK 9 9 9 9 9 9 7 MAK 9 9 9 9 9 9 7 Acetone 9 9 9 7 9 9 9
Esters EMT03-059 EMT03-077 EMT03-051 EMT02-133 EMT03-039 EMT03-044
EMT02-169 HS-CAB-29 HS-CAB-46 HS-CAB-29 HS-CAB-55 HS-CAB-20
HS-CAB-20 HS-CAB-55 Isopropyl alcohol/ 3 9 1 9 1 1 9 water 90/10
C-11 ketone 1 9 1 9 1 1 9 DIBK 1 9 1 1 1 1 3 PP 5 9 7 9 5 7 9 EP 1
9 9 9 9 1 9 EB 9 9 3 9 3 3 9 MeOH 9 9 1 9 1 1 9 Tescol C (95) 1 9 1
9 1 1 9 Toluene 1 9 1 9 3 3 3 Xylene 1 1 1 1 1 1 3 n-butyl acetate
9 9 7 9 5 7 9 Ethyl acetate 9 9 9 9 7 7 9 Texanol 3 9 9 9 7 1 9
2-EH acetate 1 9 1 9 1 1 3 EEP 9 9 7 9 7 7 9 PM 9 9 9 9 7 7 9 PB 9
9 9 9 7 7 9 PM acetate 9 9 9 9 9 7 9 EB acetate 9 9 9 9 9 7 9 MPK 9
9 9 9 7 7 7 MEK 9 9 9 9 9 7 9 MAK 5 9 7 9 7 7 9 Acetone 9 9 9 9 9 9
9 Esters EMT03-062 EMT03-040 Isopropyl 9 1 alcohol/water 90/10 C-11
ketone 5 1 DIBK 3 1 PP 9 5 EP 9 9 EB 9 3 MeOH 9 1 Tescol C (95) 9 1
Toluene 3 3 Xylene 1 1 n-butyl acetate 9 5 Ethyl acetate 9 7
Texanol 9 7 2-EH acetate 5 1 EEP 9 7 PM 9 9 PB 9 7 PM acetate 9 9
EB acetate 9 9 MPK 9 7 MEK 9 9 MAK 9 9 Acetone 9 9
Example 50
[0214] Inventive HS-CAB-17 and HS-HS-CAB-38 esters are evaluated as
pigment grinding vehicles for inks or coating. Eight millbases and
eight ink formulations are prepared as described in Table 20.
Compared to conventional CAB grades, color development (color
strength) of inventive HS-CAB's is equal or better.
TABLE-US-00021 TABLE 20 291-1 291-2 291-3 291-4 291-5 291-6 291-7
291-8 Millbases CAB-381-0.1 Solution (290-1) 25 25 HS-CAB-38
Solution (290-2) 25 25 CAB-171-15 Solution (290-5) 25 25 HS-CAB-20
Solution (290--6) 25 25 Blue 15:3 Pigment (Aarbor) 25 25 25 25
VT8015 Violet Pigment (Uhlich) 25 25 25 25 Ethanol/Ethyl Acetate
(70:30) Blend 50 50 50 50 Ethyl Acetate/Ethanol (70:30) Blend 50 50
50 50 Total 100 100 100 100 100 100 100 100 INKS Millbases 50 50 50
50 50 50 50 50 CAB-381-0.1 Solution (290-1) 35 50 HS-CAB-38
Solution (290-2) 35 35 CAB-171-15 Solution (290-5) 35 35 HS-CAB-20
Solution (290-6) 35 35 Ethanol/Ethyl Acetate (70:30) Blend 15 15 15
15 Ethyl Acetate/Ethanol (70:30) Blend 15 15 15 15 Total 100 100
100 100 115 100 100 100 Color Strength (bleached white, %) 100 100
100 100 80 100 80 100 Transparency on Leneta (RK#2) 1 1 1 1 3 2 1 1
Gloss @ 60 on Leneta White (RK#2) 6 1.2 1.4 1.1 36 40 32 23 Gloss @
60 on C1S 7 1.4 1.4 0.7 34 37 31 32 Adhesion on Leneta Black 5 1 4
1 5 2 5 2 Adhesion on Leneta White 5 2 3 2 5 2 1 2 Adhesion on PP 4
2 1 2 4 1 1 3 Adhesion on White PE 1 3 1 2 1 2 1 3 Block Resistance
(F) @ 40 psi, 1 sec on C1S 270 230 400+ 400+ 270 230 400+ 400+
Water Resistance on PP 5 5 5 5 5 4 5 5 Water Resistance on White PE
5 3 5 5 5 3 5 5 Alcohol Resistance on PP 1 1 1 1 1 1 1 1 Alcohol
Resistance on White PE 1 1 1 1 1 1 1 1 Alkali Resistance on PP 5 5
5 5 5 4 5 5 Alkali Resistance on White PE 5 1 5 5 5 2 5 4 409
Resistance on PP 5 5 4 1 5 3 3 4 409 Resistance on White PE 4 3 1 1
2 1 5 1 Rating: 1 = Poor; 5 = Excellent Samples are ranked relative
to a standard.
Example 51
Improved Melt Stability of HS-CAB's
[0215] An inventive HS-CAB-38, having a glass transition
temperature (T.sub.g) of 89.degree. C. and a melt temperature of
120.degree. C., is placed on a preheated 2-roll horizontal mill
(80.degree. C.). The HS-CAB powder adheres to the Roll and the
temperature is gradually increased until the HS-CAB begins to
soften and flow (-100.degree. C.). It is noted that this material
appears to have good thermal stability. After nearly 30 minutes on
the mill, the CAB has not yellowed.
Example 52
HS-CAP-48: High Propionyl, Low DP CAP
[0216] A 2 L-reaction kettle was charged with a propionic acid-wet
activated cellulose (311.77 g total, 160 g dry cellulose), prepared
according to Example 1, except that the butyric acid wash was
replaced with a propionic acid wash. Propionic acid (262.5 g) and
acetic acid (5.22 g) were added to the kettle. The mixture was
cooled to -10.degree. C. A mixture of propionic anhydride (757.69
g) and sulfuric acid (5.44 g) were cooled to -30.degree. C. and
then added to the reaction kettle. The mixture was stirred for 1
hour at room temperature. The mixture was then heated to 70.degree.
C. Sulfuric acid (5.44 g) was added to the clear dope approximately
1 hour after the room temperature hold. The mixture was then
stirred at 70.degree. C. and stirred for 3 hours and 52 minutes. A
mixture of water (182.5 g) and acetic acid (498.4 g) was slowly
added to the clear "dope." The mixture was stirred for 24 hours at
70.degree. C. The catalyst was neutralized by the addition of
Mg(OAc).sub.4 (14.1 g) dissolved in HOAc (475 g) and water (195 g).
The neutralized dope was filtered at approximately 50.degree. C.
through a glass wool-covered coarse fritted funnel. The product was
precipitated by pouring, with rapid mixing, the clear, neutralized
dope into 20-30 volumes of water. Decanting away the filtration
liquid and adding fresh deionized water and then allowing the
precipitate to stand in the fresh water for several hours hardened
the precipitate. The precipitate was washed extensively with
deionized water for at least 2 hours. The product was dried in a
vacuum oven at approximately 50.degree. C. overnight. The product
had the following composition: DS.sub.Pr=1.75; DS.sub.Ac=0.22;
M.sub.n=3887; M.sub.w=7036; Polydispersity=1.81; IV
(PM95)=0.086.
Example 53
Coating Formulations with HS-CAB-38 and Evaluation
[0217] Clearcoat formulations are prepared according to Tables
21-22 and the resulting coatings are evaluated to determine the
effect different levels of HS-CAB-38 (Sample 4, Table 4) have on
dry-to-touch time, hardness development, and gloss.
TABLE-US-00022 TABLE 21 Solvent Blend n-Butyl Acetate 66.0 Xylene
34.0 Total 100.0
TABLE-US-00023 TABLE 22 Formulations with HS-CAB-38 0% CAB 2% CAB
4% CAB 8% CAB Synocure 851 S (60%) 48.8 48.5 47 46 (Xylene:n-Butyl
Acetate) (2:1) HS-CAB-38 (50%) -- 1.2 2.3 4.8 (n-Butyl Acetate)
Eastman EEP.sup.(1) 4.1 4 3.9 3.8 Solvent blend 27.4 26.6 27.5 26.3
Desmodur N 75 BA 19.7 19.7 19.3 19.1 (75%) (n-Butyl Acetate) Total
100 100 100 100 DIN 4 viscosity 19.5 19.7 19.2 19.5 (seconds)
Theoretical % Total 44.1 44.5 43.8 44.3 Solids Content
.sup.(1)Ethyl 3-ethoxypropionate Synocure 851 S: 4.5% OH
content
[0218] Dry-To-Touch Time
[0219] Coatings re prepared (Tables 21-22) with an OH:NCO
stoichiometry of 1:1, and a DIN 4 viscosity of 18-20 seconds.
Coatings are prepared with 0% CAB and with 2%, 4% and 8% of the
hydroxy-functional acrylic substituted with the HS-CABs. Each of
the coatings is spray applied to Chemetall Gold Seal, high zinc
phosphate 1.0 mm steel panels using a DeVilbiss JGA 545 spray gun
at 55 psi air pressure. Three panels are coated for each test
ratio, such that a range of dry film thickness including 45 pm is
obtained. The dry-to-touch time is evaluated by a thumb print test
(according to ASTM D 1640 section 7.4.2).
TABLE-US-00024 TABLE 23 Dry-To-Touch Time (Minutes) Example # 0%
CAB 2% CAB 4% CAB 8% CAB 53 HS-CAB-38 230 207 184 180
[0220] The results of the dry-to-touch times are shown in Table 23.
The shortest dry-to-touch times are achieved as the level of
HS-CAB-38 (Sample 4, Table 4) is increased.
[0221] Hardness Development
[0222] Each of the panels is also assessed for hardness development
by Konig pendulum hardness evaluations. Tests are carried out after
24 hours and continued every 24 hours up to 168 hours. The panels
are stored at 23.degree. C. during this period.
TABLE-US-00025 TABLE 24 Hardness Development with HS-CAB-38, Konig
Pendulum Hardness (Seconds) Hours 0% CAB 2% CAB 4% CAB 8% CAB 24 23
22 21 21 48 71 68 67 70 72 104 101 99 103 144 143 139 140 142 168
183 180 182 184
[0223] Konig pendulum hardness results are shown in Table 24. After
24 hours and at the end of the 7 days test period, the HS-CAB-38
content of each set of coatings has little effect on the Konig
pendulum hardness.
Example 54
HS-CABs as Flow Additives in Automotive Monocoat Formulations:
General Formulations
[0224] A white-pigmented high solids coating using a hybrid
acrylic-isocyanate-polyester system is developed which can be
sprayed at 70% solids and 18 second Ford Cup #4 viscosity (Tables
25 and 26). An ultra high solids master batch consisting of TRONOX
CR828 (titanium dioxide pigment), Rohm and Haas AU608X (acrylic
polyol), and Sherwin-Williams US-2 solvent (paint thinner) are
mixed together under high shear. To this, CAB, BYK.RTM. 325, or a
combination of the two are added along with the isocyanate portion,
(Bayer Desmodur N 3300) and Bayer Desmophen 800 (polyester polyol)
used to keep the OH/CN balance. The Brookfield viscosities are
measured at the same solids prior to the addition of the
isocyanate. After the isocyanate is added, the spray viscosities
are adjusted with the addition of Sherwin-Williams US-2 thinner to
18-20 second Ford Cup #4 and sprayed using a DeVibliss air assisted
spray gun at 35 pounds of pressure. Two panels of each formulation
are sprayed. After flash-off for 40 minutes at room temperature,
the panels are baked in an oven at 82.degree. C. (180.degree. F.)
for 30 minutes. Before any of the panels are tested, the baked
panels are laid horizontally in a constant temperature-humidity
room at 24.degree. C. (70.degree. F.) and 50% relative humidity for
7 days.
TABLE-US-00026 TABLE 25 Pigment Dispersion Rohm and Haas AU608X (OH
Functional Acrylic) 41.42 TRONOX 828 (Titanium Dioxide Pigment)
56.66 Sherwin Williams US-2 Thinner 1.92
[0225] The pigment dispersion is mixed in an Eiger High Speed
Disperser until the particle size is <0.1 micron on a Hegmann
gauge. This is achieved by mixing at 300 rpm for 5 minutes,
allowing the solution to cool and repeating 5 times.
TABLE-US-00027 TABLE 26 5 formulations with 4 types of cellulose
esters B: No CAB/ C: With D: With 1/2 E: With A: No CAB/ With
CAB/No CAB/With 1/2 CAB/With No BYK .RTM.325 BYK .RTM.325 BYK
.RTM.325 BYK .RTM.325 BYK .RTM.325 Bayer 15.04 15.04 15.04 15.04
15.04 Desmodur N 3390 Pigment 57.84 57.84 57.84 57.84 57.84
Dispersion (II above) US-2 Thinner 12.75 12.75 9.08 10.91 9.08
Bayer 14.37 14.37 10.70 12.53 10.70 Desmophen 800 CAB (50 wt % 0 0
7.34 3.67 7.34 solution BYK .RTM. 325 0 0.50 0 .25 0.5 Total 100.00
100.50 100.00 100.25 100.50
[0226] Two panels are sprayed for each paint type (Table 26-Columns
A,B,C,E) along with center point replicates, (formulation 26-D
paints). The samples are tested for pencil hardness.sup.1, pendulum
rocker hardness (Konig),.sup.2 Tukon Hardness (Knoops), orange
peel, smoothness, gloss by wave guide measurements (long and short
waves), gloss at 20 degrees and 60 degrees,.sup.3 distinctness of
image (DOI),.sup.4 experimental solids, Brookfield viscosity,.sup.5
Ford Cup viscosity, MEK Double Rubs,.sup.6 thickness,.sup.7 tape
pull adhesion tests,.sup.8 and a visual inspection for pinholes and
craters. .sup.1ASTM Method D3363-00, "Standard Test Method for film
hardness by pencil test.".sup.2ASTM Method D4366-95, "Standard Test
Methods for hardness of Organic Coatings by Pendulum Damping
Tests.".sup.3ASTM Method D523-89 (1999), "Standard Test Method for
Specular Gloss.".sup.4ASTM Method D5767-95 (1999), "Standard Test
Methods for Instrumental Measurement of Distinctness-of-Image Gloss
of Coating Surfaces.".sup.5ASTM Method D2196, "Test Methods for
Rheological Properties of Non-Newtonian Materials by Rotational
(Brookfield) Viscometer.".sup.6ASTM Method 5402, "Practice of
Assessing the Solvent Resistance of Organic Coatings Using Solvent
Rubs.".sup.7ASTM Method D1186, "Test Method for Nondestructive
Measurement of Dry film thickness of Nonmagnetic Coating Applied to
a Ferrous Base.".sup.8ASTM Method D3359,"Test Methods for Measuring
Adhesion by Tape Test."
[0227] HS-CAB-55 (Sample 5, Table 4) and HS-CAB-38 (Sample 4, Table
4) provide the same anti-cratering, anti-mounding and
anti-pinholing property as CAB-381-0.1 and CAB-551-0.01 yet at much
higher application solids. All the panels which do not contain
cellulose ester have pinholes or craters. HS-CAB-55 and HS-CAB-38
do not hurt the adhesion of paint to the substrate. Furthermore,
HS-CAB-38 and HS-CAB-55 do not hurt Tukon hardness, as no samples
are found to be significantly worse than others. 20 and 60 degree
Specular Gloss are not hurt by the addition of HS-CAB-38 or
HS-CAB-55. The addition of CAB-381-0.1 hurts 20 degree gloss values
when compared to all other samples. Gloss by short-wave Wave-Scan
measurements indicate that HS-CAB-38 and HS-CAB-55 are the
smoothest samples. They are considerably better than standard
cellulose esters yet the solids are much higher.
Examples 55-59
Pigmented Thermoplastic Automotive Basecoat
[0228] HS-CAB-17 (Sample 3, Table 4) and HS-CAB-38 (Sample 1, Table
4) are evaluated as metallic flake control agents in a high solids
basecoat useful for automotive coatings. Five formulations are
prepared as described in Table 27. The formulations are sprayed
onto metal panels using a spray technique altered to accommodate
for the higher solids. The formulations are reduced with
xylene/n-BuOAc to obtain the same solids level as Example 55 (i.e.
69%). Example 55 contains HS-CAB-17, Example 56 contains HS-CAB-38,
Example 57 (Comparative) is the control and contains no metallic
flake control agent, and Examples 58 and 59 contain the microgel
metallic flake control agent R-1623-M3.
TABLE-US-00028 TABLE 27 Example # 55 56 57 58 59 HS-CAB-17
(60%).sup.9 30 0 0 0 0 HS-CAB-38 (60%).sup.10 0 30 0 0 0 Coroc
R-1623-M3 0 0 0 10 10 Reactol 175 (80%) 20 20 50 50 60 Cymel 301 20
20 20 20 20 Stapa Metalux 20 20 20 20 20 Mica 2 2 2 2 13 EEP 8 8 8
0 2 Total 100 100 100 102 126 Panel Appearance.sup.11 Excellent
Fair Poor Poor Good Adjusted Appearance NA NA Good Good NA
.sup.960% solids in MEK, Batch EMT02-085 .sup.1060% solids in MEK,
Batch EMT02-113 .sup.11When sprayed at 69% solids
[0229] Excellent appearance is achieved at a solids level of 69%
weight solids compared to a commonly used control of 52% weight
solids. Example 55 exhibits excellent appearance and good holdout
from the OEM clear. The coating also exhibits good travel or flop.
The appearance is poor with Examples 57-59 when sprayed at 69%
solids. The appearance of Example 56 is fair.
[0230] Further reduction is done with the control formulations and
the formulations containing the microgels until a good appearance
is obtained. For example, the amount of solids for Example 57 is
52.4 in order to obtain similar appearance as Example 55.
[0231] Once basecoats with approximately equal appearance are
prepared, one half of each panel is then sprayed with a commercial
2-component urethane clearcoat, DuPont OEM TSA, and baked at
121.degree. C. (250.degree. F.) for 20 minutes. Flop/Travel is
measured for each cured panel (see Table 28). Example 55
(HS-CAB-17) has good appearance and travel, Example 59 (no CAB or
microgel) has good appearance and fair travel when reduced to 52.4%
solids, and Example 59 (HS-CAB-38) has fair appearance and poor
travel, indicating that there is "strike in" of the basecoat by the
topcoat solvents.
TABLE-US-00029 TABLE 28 Example # Notebook # Additive Flop/Travel %
Solids 55 X-19870-16 HS-CAB-17 12.22 69 58 X-19870-18 R-1623-3M
10.67 54 56 X-19870-20 HS-CAB-38 10.25 69
Example 60
Low Molecular Weight CAB's in Urethane Clearcoat Formulation
[0232] A new CAB/Acrylic/Urethane formulation is developed loosely
based on a combination of two Eastman Publications (E-321 &
TT-96-SOL-2A). The purpose of this new formulation is to show the
improved flow properties and quicker dry-to-touch time of acrylic
isocyanate formulation when CAB-551-0.01 is added. Then, determine
if the HS-CAB will give similar improvements without contributing
as greatly to viscosity.
[0233] The following formulations are prepared:
TABLE-US-00030 TABLE 29 Without CAB With CAB (grams) (grams) 70.93
53.89 Rohm & Haas Paraloid AU-608B Acrylic (60% solids in
n-Butyl Acetate) 0.00 23.52 CAB (50% solution in acetone) 0.45 7.27
n-Butyl Acetate 11.76 0.00 Acetone 0.59 0.59 Dibutyltin Dilaurate
(DBTDL) catalyst (1% in n-Butyl Acetate) 16.26 14.73 Bayer Desmodur
N-100 Aliphatic Isocyanate (100% Solids) 100.00 100.00 Total
[0234] Formulation Constants
TABLE-US-00031 58.8 wt. % Solids Acrylic/CAB/Isocyanate Ratio
55/20/25 41.2 wt % solvent 71.5% n-Butyl Acetate, 28.5% Acetone
[0235] Isocyanate/Polyol Ratio 1.2/1
[0236] DBTDL catalyst level 0.01% based on solids
Examples 61-66
Evaluation of HS-CAB-38 in Urea Formaldehyde Coatings
[0237] A series of formulations containing HS-CAB (Sample 4, Table
4), at 4 different levels), CAB-381-0.1, and no CAB, are prepared
as described in Table 30. Table 36 shows the viscosity of the
systems at 22.3% solids for the CAB-381-0.1 and 24.3% solids for
the rest. The use of HS-CAB-38 gives formulations with viscosities
approximately one tenth that of formulations using the CAB-381-0.1
control and one third that of the control without CAB. The
HS-CAB-38 samples are applied at a solids level of 40%,
approximately twice that of the controls.
[0238] The samples are spray applied and allowed to cure for one
week prior to evaluation. All samples pass chemical resistance
tests with greater than 200 MEK double rubs.
[0239] The results of both forward and reverse impact are listed in
Table 36. Forward impact drops with the initial change in ratio of
the acrylic polyol to HS-CAB-38 but does not change with subsequent
alterations. Reverse impact is poor in all cases with no notable
differences.
[0240] Table 31 also lists the 60.degree. gloss for each example.
Gloss is not reduced appreciably even at high levels of HS-CAB-38.
The one exception is the 25:45 ratio of AU608X to HS-CAB-38. This
sample yields values that are up to 9 points lower.
[0241] Crosshatch adhesion is 100 percent retained with all
samples.
[0242] In this evaluation the HS-CAB-38 samples in all ratios yield
higher hardness values than do CAB-381-0.1.
TABLE-US-00032 TABLE 30 Formulations of HS-CAB-38/Urea Formaldehyde
Coatings Ex. #61 Ex. #62 Ex. #63 Ex. #64 Ex. #65 Ex. #66 Paraloid
28.2 16.6 18.2 14.1 10 0 AU608X Cymel U80 7.2 6.5 7.2 7.2 7.2 7.2
CAB-381-0.1 0 18.2 0 0 0 0 HS-CAB-38 0 0 6 8.5 10.8 16.9 n-Butyl
Acetate 38.4 34.9 40.8 41.8 42.8 45.2 Xylene 25.7 23.3 27.3 27.9
28.7 30.2 pTSA.sup.A 0.5 0.4 0.5 0.5 0.5 0.5
TABLE-US-00033 TABLE 31 Evaluation of HS-CAB-38/Urea Formaldehyde
Coatings Ex. #61 Ex. #62 Ex. #63 Ex. #64 Ex. #65 Ex. #66 Wt. %
Solids 24.3 22.3 24.3 24.3 24.3 24.3 Viscosity cP of 18.5 56.8 7.3
5.5 5 4 above solids Application 24.3 22.3 40 40 40 40 solids MEK
Double >200 >200 >200 >200 >200 >200 Rubs Impact
30 30 30 20 20 20 Forward (psi) Impact Reverse <10 <10 <10
<10 <10 <10 (psi) Gloss 93 91 92 92 84 90 Adhesion 100 100
100 100 100 100 Konig 195 178 180 186 184 184
[0243] In the drawings and specification, there have been disclosed
typical preferred embodiments of the invention and, although
specific terms are employed, they are used in a generic and
descriptive sense only and not for purposes of limitation, the
scope of the invention being set forth in the following claims.
* * * * *