Note: Descriptions are shown in the official language in which they were submitted.
PAPER COATING COMPOSITION CONTAINING HIGH STARCH LEVELS
[0001] This Application claims priority to US Provisional Patent
Application Serial Number
62/809177 filed February 22, 2019 and US Provisional Patent Application Serial
Number
62/855461 filed May 31, 2019.
[0002] Described herein is coating starch composition comprising a starch
and a plasticizer,
as well as a paper coating composition comprising said coating starch
composition, where the
paper coating composition contains at least 2% starch, a dry solids content of
at least 40%, and a
viscosity of less than about 1200 cPs, as well as methods of using and making
such
compositions, such as, for example, in paper manufacturing processes. The
paper and board
produced with one or more paper coating composition described herein meets
desired strength
requirements without having to add more starch before applying said one or
more paper coating
composition via, e.g., the coaters (i.e., eliminates, e.g., the addition of
starch via a wet stack
calendering or size press step).
[0003] The following description is provided to assist the understanding of
the reader. None
of the information provided or references cited is admitted to be prior art to
the compositions and
methods disclosed herein.
[0004] Coated paper and paperboard require a certain level of surface
strength to withstand
the stresses of the ink tack in a printing process. To further increase the
surface strength of paper
or paperboard, the surface of the paper or paperboard is often treated with a
first coating of starch
applied at, e.g., a wet stack calender or size press prior to being coated
with a second coating of
starch via a paper coating composition. Manufacturers employing a wet stack
calender in the
paper-making/paperboard-making process frequently sacrifice machine speed,
board density
(e.g., too heavy for a given caliper), quality, and uptime associated with the
use of, e.g., a wet
stack calender or size press. Moreover, adding starch via a first coating at,
e.g., a wet stack
calender or size press before coating the paper or paperboard with a second
coating of starch via
the paper coating composition at, e.g., a coater increases the costs
associated with manufacturing
the paper or paperboard. As a result, there is a need to eliminate the first
coating of starch
applied at, e.g., a wet stack calender or size press, before coating the paper
or paperboard with a
second coating of starch via a paper coating composition at, e.g., a coater
without compromising
the surface strength and quality of the resulting paper or paperboard.
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[0005]
Disclosed herein is one or more paper coating composition containing the level
of
starch required to produce paper or board with the required surface strength
and quality while
still having the desired viscosity and solids content that manufacturers
demand, and which also
enables the first coating of starch that was applied at, e.g., a wet calender
or size press to be
eliminated. More specifically, described herein is one or more paper coating
composition
comprising a coating starch composition comprising a starch and a plasticizer,
wherein said
paper coating composition contains at least about 2%, from about 2% to about
30%, from about
2% to about 25%, from about 2% to about 22%, or from about 2% to about 10%
starch. Another
embodiment describes one or more paper coating composition that has (i) a
viscosity of less than
1200 cPs, about 100 to about 1200 cPs, about 200 to about 1200 cps, or about
300 to about
600cPs and a solids content of at least 40%, 45%, 50%, 55%, 60%, 65% or 70%
dry solids (ds)
basis, or (ii) a viscosity of about 300 to about 600 cPs and a solids content
of at least 600/o dry
solids (ds) basis; and, optionally, wherein the viscosity is measured on a
Brookfield Viscometer
at 20 rpm at 18.3 C. Still a further embodiment describes a coating starch
composition
comprising a starch and a plasticizer, where the coating starch composition
has a starch and
plasticizer solids level of at least 40% ds basis. Yet still a further
embodiment describes a
coating starch composition containing 1 part starch for each 1, 1.5, 2, 2.5,
3, 3.5, or 4 parts
plasticizer. An even still further embodiment describes a paper coating
composition containing
from 2 to 20 parts of the starch and from 5 to 35 parts of the plasticizer,
from 2 to 10 parts of the
starch and from 5 to 25 parts of the plasticizer, or 10 parts of the starch
and 25 parts of the
plasticizer. A still yet further embodiment describes a paper substrate
comprising, on at least one
surface, one or more paper coating composition described herein.
[0006]
Another embodiment disclosed herein provides a method of manufacturing a dry-
finished, coated paper or paperboard product comprising applying one or more
paper coating
composition described herein to at least one side of a paper or paperboard,
and obtaining a dry
finished, coated paper or paperboard. Yet another embodiment disclosed herein
provides a
method of manufacturing a dry-finished, coated paper or paperboard product
comprising
applying one or more paper coating composition described herein to at least
one side of a paper
or paperboard, and obtaining a dry finished, coated paper or paperboard, with
the proviso that the
method does not comprise a wet stack calendering step prior to applying one or
more paper
coating composition described herein. Some embodiments describe one or more
methods where
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no starch is applied to the paper or paperboard prior to or after the
application of one or more
paper coating composition described herein. In some embodiments, one or more
method
described herein eliminates the use of a wet stack calendering step prior to
the application of one
or more paper coating composition described herein. In some embodiments, one
or more paper
coating composition described herein is applied to the paper or paperboard at
a coater.
[0007] Still other embodiments describe a dry-finished, coated paper or
paperboard product
produced from one or more method described herein. In some embodiments, the
dry-finished
paper or paperboard is characterized by a surface strength equivalent to that
of a wet-finished
paper or paperboard product as measured by an IGT pick and blister test.
[0008] It is to be appreciated that certain aspects, modes, embodiments,
variations, and
features of the present technology are described below in various levels of
detail in order to
provide a substantial understanding of the present technology. The definitions
of certain terms
as used in this specification are provided below. Unless defined otherwise,
all technical and
scientific terms used herein generally have the same meaning as commonly
understood by one of
ordinary skill in the art to which this present technology belongs.
I. Definitions
[0009] The following terms are used herein, the definitions of which are
provided for
guidance.
[0010] The use of the terms "a" and "an" and "the" and similar referents in
the context of
describing the elements (especially in the context of the following claims)
are to be construed to
cover both the singular and the plural, unless otherwise indicated herein or
clearly contradicted
by context. Recitation of ranges of values herein are merely intended to serve
as a shorthand
method of referring individually to each separate value falling within the
range, unless otherwise
indicated herein, and each separate value is incorporated into the
specification as if it were
individually recited herein. All methods described herein can be performed in
any suitable order
unless otherwise indicated herein or otherwise clearly contradicted by
context. The use of any
and all examples, or exemplary language (e.g., "such as") provided herein, is
intended merely to
better illuminate the embodiments and does not pose a limitation on the scope
of the claims
unless otherwise stated. No language in the specification should be construed
as indicating any
non-claimed element as essential.
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[0011] As used herein, "about" will be understood by persons of ordinary
skill in the art and
will vary to some extent depending upon the context in which it is used. If
there are uses of the
term which are not clear to persons of ordinary skill in the art, given the
context in which it is
used, "about" will mean up to plus or minus 10% of the particular term.
[0012] As used herein, the term "DE" or "Dextrose Equivalent" refers to the
degree of starch
hydrolysis, specifically reducing the value of a starch hydrolysate compared
to the reducing
value of an equal weight of dextrose, expressed as percent, dry basis, as
measured by the Lane
any Eynon method described in Standard Analytical Method E-26, Corn Refiners
Association,
6th Edition 1977, pp. 1-3.
[0013] As used herein, the term "DP" refers to the number of saccharide
units. For example
"DP1" saccharide is intended herein to refer to a monosaccharide, such as
dextrose.
[0014] As used herein, "dry finish" or "dry finished" is paper or
paperboard to which no
starch is added at, e.g., a wet stack calender prior to, e.g., a coater.
[0015] As used herein, "low sugar syrup" means a syrup that has low mono-
and di-
saccharide content, such as, for example, a DPI + DP2 content less than about
65%, less than
about 25%, or less than about 20%, less than about 19%, less than about 18%,
less than about
17% less than about 16%, less than about 15%, less than about 14%, less than
about 13%, less
than about 12%, less than about 11%, or less than about 10%. Exemplary
commercial low sugar
syrups include but are not limited to VERSASWEETTm 1524 low sugar glucose
syrup
VERSASWEET 1526 low sugar glucose syrup, VERSASWEET 1526 NGM low sugar
glucose syrup, VERSASWEET 1531 low sugar glucose syrup, STABLESWEET glucose
syrup, BIOLIGIO ML6810 glucose syrup (Ingredion Inc.), MULTIVANTAGE syrup
(Tate &
Lyle), VERSYRATM reduced sugar corn syrup, and CLEARDEX corn syrup (Cargill).
[0016] The terms "paper," "paperboard," "recycled board," and "board," are
used
interchangeably herein. Paper and paperboard are sheet materials made up from
an interlaced
network of cellulose fibers. The distinction between paper and paperboard is
not great; however,
in general, paperboard is thicker than paper and has a higher weight per unit
area. Paper over
200 g/m2 is defined by the International Organization for Standardization
(ISO) as paperboard or
board. However, some products are known as paperboard even though they are
manufactured in
grammages less than 200 g/m2, Broad classes within paperboard include
containerboard,
boxboard, and all other paperboard. "Recycled paperboard" is paperboard
manufactured using
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recovered paper, such as newspapers, corrugated containers, and mixed papers.
Recycled
paperboard containers include, but are not limited to, linerboard and
corrugating medium,
folding boxboard used for packaging cereal and other food products, soap
powders, and other dry
products, and set-up boxboard. Recycled paperboard is also used for many non-
packaging
products, including but not limited to, gypsum wallboard facing, tubes, cans,
drums, matches,
tags, tickets, game boards, and puzzles.
[0017] As used herein, a "plasticizer" means any material that competes for
hydrogen
bonding with starch molecules and thus disrupts hydrogen bonding between the
starch
molecules. This increases the flexibility of a film made with starch and other
components.
Examples of materials that plasticize starch include glycerin/glycerol, urea,
formamide, citric
acid (and other carboxylic acids), ethylene glycol, sugars (e.g. sucrose),
maltodextrins, dextrin,
starch derived syrups (such as corn syrup), and sugar alcohols (e.g., sorbitol
and maltitol). Many
of the plasticizers, especially the sugars, maltodextrins, and starch derived
syrups listed above
are or can be derived from a carbohydrate source such as starch. Starch can be
obtained from
any farinaceous material including, but not limited to, for example, corn,
dent corn, waxy corn,
wheat, potato, tapioca, peas, sorghum, manioc, sago, and rice.
[0018] As used herein, "wet finish" or "wet finished" is paper or
paperboard made by adding
starch at, for example, a wet stack calender prior to also being added at, for
example, a coater.
[0019] As used herein, "IGT Coating Blister" refers to a physical test that
measures the
surface strength of coating layers applied to paper or paper board. The test
predicts the point
where forces applied to the board through ink tack build in printing causes
the internal layers of
the board to blister and is used to predict or measure the potential
printability of the board
coating layers.
[0020] As used herein, "IGT Coating Pick" refers to a physical test that
measures the surface
strength of coating layers applied to paper or paper board. This test is used
to measure the ability
of a coating to resist picking as a function of increasing ink tack build with
increasing velocity.
[0021] As used herein, "basis weight" refers to the weight of a paper or
paperboard for a
defined area.
[0022] As used herein, "caliper" means the thickness of the paper or
paperboard.
[0023] As used herein, "base coat weight" refers to the weight of the
coating when applied to
a defined area as a base coat.
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[0024] As used herein, "coated brightness" refers to an optical measurement
of the coated
paper or paperboard surface for the brightness or whiteness of the surface. It
is a measure of the
visual appearance of the paper or paperboard.
[0025] As used herein, "Appearance DMM" means the appearance according to
DuPont
mottle measurement, which is a quantification of the amount of surface mottle
measured when a
paper or paper board is scanned under a diffuse lighting scanner. It is a
measure of the visual
appearance of the paper or paperboard.
[0026] As used herein, "Appearance DAV2" means the appearance according to
DuPont
Appearance Value (version 2), which is an optical test that measures the
visual appearance of a
paper or paper board surface under several lighting or illumination sources.
It is a measure of the
visual appearance of the paper or paperboard.
[0027] As used herein, "Sheffield smoothness" is a measurement of the
smoothness of a
surface of a paper or paper board.
General
[0028] Coated paper and paperboard require a certain level of surface
strength to withstand
the stresses of the ink tack in a printing process. The surface of the paper
or board is typically
treated with a first coating of starch applied at, e.g., a wet stack calender
or size press, followed
by a second coating of starch applied at, e.g., a coater. In a coated paper or
board manufacturing
process that involve the application of a first coating of starch at, e.g., a
wet stack calender,
manufacturers sacrifice machine speed, board density, quality, and uptime.
[0029] In conventional coated paperboard manufacturing processes, rawstock
from the paper
machine is surface sized and then machine calendered prior to coating. During
sizing,
substances such as gelatin, rosin, starch, or other synthetic substances, are
added to paper board
to improve resistance of the paperboard to liquid or vapor. Calendering is a
process that smooths
and controls the caliper or thickness of the paperboard. In a typical wet
stack calendering
process, water from one or more water boxes is applied to the paperboard to
enhance the
calendering results and add binders like starch, but not without detrimental
side effects. For
example, a wet calendaring step causes the caliper of the paperboard to be
reduced while also
increasing its density. Accordingly, in order to achieve a certain caliper,
additional rawstock will
be required, resulting in additional raw materials costs. In addition, wet
finishing creates
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operating problems including surface mottling of the paperboard, web breaks,
and corrosion on
the machine.
[0030] A particular challenge associated with removing the first coating of
starch applied at,
e.g., a wet stack calender or size press, before the paper or board is coated
with the second
coating of starch via the paper coating composition subsequently applied at,
e.g., a coater, is
maintaining the surface strength and quality of the paper or paperboard being
manufactured. A
further challenge with eliminating the first coating of starch applied at,
e.g., a wet stack calender
or size press, is providing a paper coating composition that contains enough
starch to provide the
desired surface strength and quality while also having the desired viscosity
and solids content
manufacturers demand. Starch is often applied as a strengthening agent during
the paperboard
manufacturing process. To further increase the surface strength of the
paperboard, it may be
desirable to increase the amount of starch in the paper coating composition;
however, increasing
the level of starch in the paper coating composition will result in a highly-
viscous, gel-like
composition that is difficult to handle, pump, and/or mix with other
ingredients, and therefore
may negatively impact the production speed of the manufacturing equipment.
[0031] Accordingly, there is a need to develop a paper coating composition
that will
maintain an appropriate coating viscosity for application during paperboard
manufacturing,
impart the desired strength characteristics to the manufactured paperboard,
have the desired
solids content to limit the amount of water that has to be driven off, and
that allows
manufacturers to eliminate the addition of starch before or after the paper or
paperboard is coated
with the starch containing paper coating composition without sacrificing the
strength and quality
of the paperboard. One or more paper coating compositions described herein
exhibit one or
more of the aforementioned benefits, including eliminating the wet stack
calendaring step and/or
the addition of starch via the wet stack calendaring or size press steps,
thereby decreasing
manufacturing costs while improving manufacturing speed.
[0032] It has been shown that the addition of a plasticizer, such as, for
example, corn syrup
to a paper coating composition in equal amounts of solids lowers the viscosity
of the paper
coating composition. At higher starch levels, the addition of a plasticizer,
such as, for example,
corn syrup maintains the viscosity of the paper coating composition. Due to
its relatively low
molecular weight, one of skill in the art would not anticipate that a
plasticizer, such as, for
example, corn syrup would be capable of improving the strengthening properties
of a paper
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coating composition. However, as demonstrated by the results described below,
one or more
paper coating composition described herein surprisingly and unexpectedly shows
that a
plasticizer, such as, for example, corn syrup in combination with starch
provides paper and board
with excellent strength over paper coating compositions that do not contain a
plasticizer, such as,
for example, corn syrup. One or more paper coating composition disclosed
herein enables a dry
finished board (no starch added at the wet stack calender) having strength
characteristics
comparable to those of a wet finished board (starch added at the wet stack
calender) to be
manufactured after only a single application of one or more starch containing
paper coating
compositions described herein to the dry finished, coated paper or board
(i.e., a single application
of one or more paper coating compositions described herein, which enables the
addition of starch
at the wet stack to be eliminated). As a result, one or more paper coating
composition described
herein enables less total starch to be unexpectedly and surprisingly used in a
paperboard
manufacturing process (e.g., ¨33 lbs/ton (-16.5 kg/metric ton) present method
vs. ¨60 lbs/ton
(-30 kg/metric ton) conventional method).
[0033] Disclosed herein is a starch coating composition and a paper coating
composition that
enables an improved, simplified paper and paper board manufacturing process.
One or more
method described herein for using one or more paper coating compositions
described herein
provides a paperboard manufacturing process that eliminates the wet stack
calendaring step,
reduce manufacturing time, improves efficiency, improves water retention,
improves runnability,
improves yield (e.g., caliper vs. basis weight), reduces costs associated with
the use of starch at
the wet calendering or size press steps, and provide greater flexibility,
without compromising the
strength and quality of the paperboard. Various embodiments can provide a dry
finished, coated
paper or board with an IGT surface strength profile that is comparable to that
of a wet finished,
coated paper or board, thereby eliminating the need for an additional starch
application at the wet
stack calendaring or size press steps. Additionally, or alternatively, in some
embodiments, one
or more composition described herein may eliminate vessel segment picking in
mills that do not
have size presses and use oak or other hard woods as part of their fiber
basket.
III. Paper Coating Compositions and Coating Starch Compositions
[0034] Described herein is a coating starch composition comprising a starch
and plasticizer,
a starch and a non-carbohydrate derived plasticizer, a starch and a
carbohydrate derived
plasticizer, or a starch and a starch derived syrup. In some embodiments, one
or more coating
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starch composition described herein has a starch and plasticizer, a starch and
a non-carbohydrate
derived plasticizer, a starch and a carbohydrate derived plasticizer, or a
starch and a starch
derived syrup solids level of at least 40% dry solids (ds) basis. In other
embodiments, one or
more coating starch composition described herein contains 1 part of a starch
for each 1, 1.5, 2,
2.5, 3, 3.5, or 4 parts of a plasticizer. In yet other embodiments, one or
more coating starch
composition described herein contains 1 part of a starch for each 2,2.5, 3,
3.5, or 4 parts of a
plasticizer. In yet other embodiments, one or more coating starch composition
described herein
contains 1 part of a starch for each 2.5 parts of a plasticizer. In still
other embodiments, one or
more coating starch composition described herein contains 1 part of a starch
for each 2.5 parts of
a starch derived syrup. In some embodiments, one or more coating starch
composition described
herein contains 1 part PEN-CO FE L800 (Ingredion) starch for each 2.5 parts
of maltose syrup
with a DE of 53, such as, for example, GLOBE(R) 55 HIM Corn Syrup (Ingredion).
[0035] Also, described herein is a paper coating composition comprising one
or more coating
starch compositions described herein. In some embodiments, one or more paper
coating
composition described herein contains at least about 2%, from about 2% to
about 30%, from
about 2% to about 25%, from about 2% to about 22%, or from about 2% to about
10% starch. In
other embodiments, one or more paper coating composition described herein has
a viscosity of
less than 1200 cPs. In some embodiments, one or more paper coating composition
described
herein has a viscosity of less than 1100 cPs, less than 1000 cPs, less than
900 cPs, less than 800
cPs, less than 700 cPs, less than 600 cPs, or less than 500 cPs, including any
and all ranges and
subranges therein. In other embodiments, one or more paper coating composition
described
herein has a viscosity of less than 1200 cPs, about 100 to about 1200 cPs,
about 200 to about
1200 cps, or about 300 to about 600 cPs including any and all ranges and
subranges therein. In
further embodiments, one or more paper coating composition described herein
has a viscosity of
about 300 to about 600 cPs. In still other embodiments, one or more paper
coating composition
described herein has a viscosity of about 600 to about 700 cPs. In even yet
other embodiments,
one or more paper coating composition described herein has a viscosity of
about 500 to about
600 cPs.
[0036] In still other embodiments, one or more paper coating composition
described herein
has a solids content of at least 40 /0 dry solids (ds) basis. In some
embodiments, one or more
paper coating composition described herein has a solids content of at least
40% ds basis, at least
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45% ds basis, at least 50% ds basis, at least 55% ds basis, at least 60% ds
basis, at least 65% ds
basis, or at least 70% ds basis. In some embodiments, one or more paper
coating composition
described herein has a solids content of at least 45 /0 ds basis, at least 50%
ds basis, or at least
60% ds basis. In yet other embodiments, one or more paper coating composition
described
herein has a solids content of about 40% to about 70% ds basis, about 50% to
about 65% ds
basis, or about 55% to about 65% ds basis. In some embodiments, one or more
paper coating
composition described herein has a solids content of about 60% to about 65% ds
basis, about
61% ds basis, about 62% ds basis, about 63% ds basis, about 64% ds basis, or
about 65% ds
basis.
[0037] In yet still other embodiments, one or more paper coating
composition described
herein has (i) a viscosity of less than 1200 cPs, about 100 to about 1200 cPs,
about 200 to about
1200 cps, or about 300 to about 600 cPs and a solids content of at least 40%,
45%, 50%, 55%,
60%, 65% or 70% ds basis, or (ii) a viscosity of about 300 to about 600 cPs
and a solids content
of at least about 60% ds basis.
[0038] In yet still an even further embodiment, one or more paper coating
composition
described herein contains at least about 2%, from about 2% to about 30%, from
about 2% to
about 25%, from about 2% to about 22%, or from about 2% to about 10% starch
and has (i) a
viscosity of less than 1200 cPs, about 100 to about 1200 cPs, about 200 to
about 1200 cps, or
about 300 to about 600 cPs and a solids content of at least 40%, 45%, 50%,
55%, 60%, 65% or
70% ds basis, or (ii) a viscosity of about 300 to about 600 cPs and a solids
content of at least
about 60% ds basis.
[0039] In still other embodiments, one or more paper coating composition
described herein
further comprises a pigment and/or a latex.
[0040] In some embodiments, one or more paper coating composition described
herein
and/or one or more coating starch composition described herein enable methods
for the
production of a dry finished board having improved surface strength and/or a
surface strength
that is comparable to a wet finished board.
[0041] In other embodiments, one or more coating starch compositions
described herein
provide a means of adding more starch to one or more paper coating
compositions described
herein while at the same time avoiding negative attributes such as increasing
the viscosity of the
paper coating composition or decreasing the solids content. In some
embodiments, one or more
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coating starch composition described herein allows the amount of starch added
to a paper coating
composition to be increased by at least 2-fold while maintaining a viscosity
suitable for coating
paper or paperboard as compared to a standard coating starch composition. In
still other
embodiments, one or more coating starch composition described herein enables
methods for
producing a dry finished board having improved surface strength and/or a
surface strength that is
comparable to a wet finished board while eliminating the need for a wet stack
calendering step in
the paper manufacturing process and/or eliminating the need to apply starch to
the board at the
wet stack calender and/or eliminating the need to apply starch to the board at
any point prior to
or after applying one or more paper coating composition containing one or more
coating starch
composition described herein. In yet other embodiments, one or more coating
starch
compositions described herein enables methods for producing a dry finished
board having
improved surface strength and/or a surface strength that is comparable to a
wet finished board
while reducing the overall amount of starch used in methods for manufacturing
paper or board
without compromising the surface strength of the paper or board. In even still
other
embodiments, one or more coating starch composition described herein enables
methods for
producing a dry finished board having improved surface strength and/or a
surface strength that is
comparable to a wet finished board while reducing the amount of starch
employed in the paper-
manufacturing method.
[0042] In some embodiments, one or more paper coating composition described
herein
comprises from 2 to 20 parts of a starch and from 5 to 35 parts of a
plasticizer. In other
embodiments, one or more paper coating composition described herein comprises
from 2 to 10
parts of a starch and from 5 to 25 parts of a plasticizer. In yet still other
embodiments, one or
more paper coating composition described herein comprises 10 parts of a starch
and 25 parts of a
plasticizer. In even yet further embodiments, one or more paper coating
composition described
herein comprises from 2 to 20 parts of a starch and from 5 to 35 parts of a
starch derived syrup.
In yet even further embodiments, one or more paper coating composition
described herein
comprises from 2 to 10 parts of a starch and from 5 to 25 parts of a starch
derived syrup. In even
yet still other embodiments, one or more paper coating composition described
herein comprises
parts of a starch and 25 parts of a starch derived syrup.
[0043] In further embodiments, one or more paper coating composition
described herein
enables methods for producing a dry finished board having improved surface
strength and/or a
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surface strength that is comparable to a wet finished board while eliminating
the need for a wet
stack calendering step in the paper manufacturing process and/or eliminating
the need to apply
starch to the board at the wet stack and/or eliminating the need to apply
starch to the board at any
point prior to or after the application of one or more paper coating
composition described herein.
In even still further embodiments, one or more paper coating composition
described herein
enables methods for producing a dry finished board having improved surface
strength and/or a
surface strength that is comparable to a wet finished board while reducing the
overall amount of
starch used in methods for manufacturing paper or board without compromising
the surface
strength of the paper or board. In yet other embodiments, one or more paper
coating
composition described herein enables methods for producing a dry finished
board having
improved surface strength and/or a surface strength that is comparable to a
wet finished board
while reducing the amount of starch used in the paper-manufacturing method.
[0044] In some embodiments, one or more coating starch composition
described herein or
one or more paper coating composition described herein allows the amount of
starch employed
in the overall paper-manufacturing method to be reduced from approximately 60
lbs starch per
ton (-30 kg/metric ton) of paperboard to approximately 33 lbs of starch per
ton (-16.5 kg/metric
ton) of paperboard. In some embodiments, one or more paper coating composition
described
herein or one or more coating starch composition described herein enables the
amount of starch
employed in the paper-manufacturing method to be reduced by at least 5%, at
least 10%, at least
15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at
least 45%, at least
50%, at least 55%, or at least 60%, including any and all ranges and subranges
therein. In some
embodiments, one or more paper coating composition described herein or one or
more coating
starch composition described herein enables the amount of starch used in the
paper-
manufacturing method to be reduced by from about 10% to about 60%, from about
15% to about
55%, from about 20% to about 50%, from about 25% to about 50%, from about 30%
to about
50%, or from about 40% to about 50%. In some embodiments, one or more paper
coating
composition described herein or one or more coating starch composition
described herein
enables the amount of starch used in the paper-manufacturing method to be
reduced by from
about 40% to about 45%. In some embodiments, one or more paper coating
composition
described herein or one or more coating starch composition described herein
enables the amount
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of starch used in the paper-manufacturing method to be reduced by from about
45% to about
50%.
A. Plasticizer
[0045] In one embodiment, the plasticizer is a non-carbohydrate derived
plasticizer, a
carbohydrate derived plasticizer, or a mixture thereof. In another embodiment,
the non-
carbohydrate derived plasticizer is selected from urea, glycerin/glycerol,
ethylene glycol,
formamide, citric acid or other carboxylic acids, and a mixture of any two or
more of the
foregoing. In another embodiment, the carbohydrate derived plasticizer is a
sugar. In still
another embodiment, the sugar is selected from a sucrose, a starch derived
syrup, a maltodextrin,
a dextrin, a sugar alcohol, or a mixture of any two or more of the foregoing.
In yet still another
embodiment, the carbohydrate derived plasticizer is a starch derived syrup. In
still another
embodiment, the sugar alcohol is a sorbitol.
[0046] The starch derived syrup may be any type of starch derived syrup
suitable for use in
paper coating formulations. In some embodiments, the starch derived syrup is
selected from a
corn syrup, a low sugar syrup, dextrose, or a mixture of any two or more of
the foregoing. In
some embodiments, the starch derived syrup is a corn syrup. In further
embodiments, the starch
derived syrup is a low sugar syrup. In further embodiments, the corn syrup is
a maltose corn
syrup or high fructose corn syrup. In some embodiments, the corn syrup is a
maltose corn syrup.
In some embodiments, the corn syrup is a high fructose corn syrup. In some
embodiments, the
corn syrup is a maltose corn syrup with a DE of 53, such as GLOBE 55 I-IM
Corn Syrup
(Ingredion). In some embodiments, the corn syrup is a high fructose corn
syrup.
[0047] In some embodiments, the starch derived syrup has a DE of about 20
to about 100. In
some embodiments, the starch derived syrup has a DE of about 30 to about 100,
about 35 to
about 100, about 40 to about 100, about 45 to about 100, about 50 to about
100, about 55 to
about 100, about 60 to about 100, about 65 to about 100, about 70 to about
100, about 75 to
about 100, about 80 to about 100, about 85 to about 100, about 90 to about
100, or about 95 to
about 100, including any and all ranges and subranges therein. In other
embodiments, the starch
derived syrup has a DE of about 20 to about 90, about 30 to about 90, about 35
to about 90,
about 40 to about 90, about 45 to about 90, about 50 to about 90, about 55 to
about 90, about 60
to about 90, about 65 to about 90, about 70 to about 90, about 75 to about 90,
about 80 to about
90, or about 85 to about 90, including any and all ranges and subranges
therein. In other
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embodiments, the starch derived syrup has a DE of about 20 to about 90, about
20 to about 100,
about 40 to about 75, about 40 to about 70, about 40 to about 44, about 49 to
about 55, about 53
or 53. In some embodiments, the starch derived syrup includes any starch
derived syrup having
a DE of about 40 to about 75. In some embodiments, the starch derived syrup
has a DE of about
40 to about 70, about 40 to about 44, about 50 to about 55, about 53 or 53.
B. Starch
[0048] In one embodiment, the starch is obtained or derived from one or a
combination of
farinaceous materials. Any farinaceous material can be used as the source of
the starch including
corn, dent corn, waxy corn, wheat, potato, tapioca, pea, sorghum, manioc,
sago, and rice, among
others. Accordingly, the starch can be comprised of one or more unmodified
starch, blends of
different types of unmodified starches, one or more modified starch, blends of
different types of
modified starches, and/or blends of modified and unmodified starches. In some
embodiments,
the starch is selected from corn starch, dent corn starch, waxy corn starch,
wheat starch, potato
starch, tapioca starch, pea starch, sorghum starch, manioc starch, sago
starch, rice starch, and a
mixture of any two or more of the foregoing. In other embodiments, that starch
is selected from
one or more of unmodified or modified corn starch, unmodified or modified dent
corn starch,
unmodified or modified waxy corn starch, unmodified or modified wheat starch,
unmodified or
modified potato starch, unmodified or modified tapioca starch, unmodified or
modified pea
starch, unmodified or modified sorghum starch, unmodified or modified manioc
starch,
unmodified or modified sago starch, unmodified or modified rice starch, and
blends of two or
more of any of the foregoing.
[0049] In some embodiments, the starch may be modified in any manner known
in the art.
In some embodiments, the starch is a thinned starch. Exemplary commercial
thinned starches,
include but are not limited to PENFORD GUM 230, PENFORD GUM 240, PENFORD
GUM 250, PENFORD GUM 260, PENFORD GUM 270, PENFORD GUM 280, PEN-
COTE , FILMKOTE 340, FILMKOTE 355, FILMKOTE 370, FILMKOTE 54,
FILMKOTE 550, FILMKOTE 70, PENFILMTm 2230, PENFILMTm 2240, StacKote 4,
StacKotee 6, or StacKotee 8 (Ingredion Inc.). In some embodiments, the thinned
starch is a
stable liquid coating starch. Exemplary stable liquid coating starches include
but are not limited
to PEN-COTE L800, PEN-COTE L1000, RediFILMrm 5400, RediFILMTm 5800, or
RediBONDTM HM12 (Ingredion Inc.). In some embodiments, the starch is a
modified starch. In
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other embodiments, the modified starch is selected from a nonionic starch, an
anionic starch, an
amphoteric starch, an etherified starch, an acetylated starch, a sulfonated
starch, and a mixture of
any two or more of the foregoing.
C. Additives/Other Components
[0050] In some embodiments, one or more paper coating composition described
herein
further comprises a pigment and/or a latex. Exemplary pigments include but are
not limited to
clay, calcium carbonate, TiO2, or any combination thereof Exemplary latexes
include but are
not limited to vinyl acrylic, polyvinyl acetate (PVAC), styrene butadiene,
styrene acrylate, or any
combination thereof In some embodiments, one or more paper coating composition
described
herein further comprises about 100 parts pigment and about 10 to about 25
parts latex.
D. Coating Applications and Surfaces
[0051] One or more paper coating composition described herein and/or one or
more coating
starch composition described herein may be adapted for use in a number of
applications,
including in compositions used in the paper-making processes. In particular,
one or more paper
coating composition described herein and/or one or more coating starch
composition described
herein are adaptable for use in coatings used to make dry finished paper and
paperboard. In
addition to paper and paperboard, one or more paper coating composition
described herein
and/or one or more coating starch composition described herein can be applied
to parchment,
cellophane, metals, textiles, or like surfaces that are wettable by water. One
or more paper
coating composition described herein and/or one or more coating starch
composition described
herein are useful, for example, in applications where contact with an aqueous
solution is
possible, such as, e.g., in offset printing.
[0052] One or more paper coating composition described herein, such as,
e.g., coatings on
paper and paperboard, are desirable for subsequent operations, such as, e.g.,
printing, and the
like. As the Examples set forth herein demonstrate, dry finished paperboard
coated with one or
more paper coating composition described herein resists picking and blistering
during offset
printing to an extent that is comparable to that of a wet finished paperboard
coated with a
standard first starch coating applied, for example, via a wet stack calendar
or size press, followed
by a second standard coating applied, for example via a coater (hereinafter
"conventional paper
coating process").
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[0053] Paper and paperboard coated with one or more paper coating
composition described
herein may have any surface strength. In some embodiments, a dry finished
paperboard coated
with one or more paper coating composition described herein has a surface
strength that is
comparable or increased relative to a wet finished paperboard coated with
standard paper coating
compositions via a conventional paper coating process. Examples of physical
tests of a
substrate's (e.g., paper, board, etc.) surface strength that correlate well
with a substrate's print
performance are the IGT pick and blister tests and wax pick tests. In
addition, both tests
correlate well with strong surface strength of paper substrates. While either
of these tests may be
utilized, the IGT pick test is preferred. In some embodiments, a dry-finished
coated paper or
paperboard product coated with one or more paper coating composition described
herein is
characterized by an IGT average increase of at least 50%, 55%, 60%, 61%, 62%,
63%, 64%,
65%, 66%, 67%, 68%, 69%, or 70% as compared to a dry-finished paper or
paperboard product
coated with standard paper coating compositions via a conventional paper
coating process
[0054] The IGT tests predict the ability of coated or uncoated paper or
paperboard to resist
picking or blistering during offset printing. The test device operates by
applying a known film
thickness of polybutyne oil of a given viscosity to an aluminum printing disk.
The oil is applied
to the disk with a standard IGT inking unity. The oil is transferred to the
sample surface while
under acceleration. The oil creates a pulling action on the paper surface,
similar to offset ink,
resulting in picking, blistering, or both. The point at which the picking and
blistering starts is the
end point of the test, The reported units for both pick and blister are
Kilopoi se-Centimeters per
second (KPCMS). At a known oil viscosity, this value relates to the velocity
or press speed that
can be achieved before the sheet is damaged.
[0055] One or more dry finished paper or board described herein may have at
least one
surface having a surface strength as measured by the IGT pick and blister test
of at least 35
KPCMS, at least 40 KPCMS, at least 45 KPCMS, at least 50 KPCMS, at least 55
KPCMS, at
least 60 KPCMS, at least 65 KPCMS, at least 66 KPCMS, at least 67 KPCMS, at
least 68
KPCMS, at least 69 KPCMS, at least 70 KPCMS, at least 71 KPCMS, at least 72
KPCMS, at
least 73 KPCMS, at least 74 KPCMS, at least 75 KPCMS, at least 76 KPCMS, at
least 78
KPCMS, at least 79 KPCMS, or at least 80 KPCMS, including any and all values
therein.
[0056] Paper coating compositions described herein can be applied to one or
both sides of
the paper or paperboard by any means known in the art. Coating methods
include, but are not
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limited to, roll applicator and metering with roll, rod, blade, bar, or air
knife; pond application
and metering with roll, rod, blade, or bar, or air knife; premetered films or
patterns; foam
application; curtain coaters; and combinations of any of the foregoing.
[0057] Subject matter contemplated by the present disclosure is set out in
the following
numbered embodiments:
1. A coating starch composition comprising a starch and a plasticizer, wherein
said
composition has a starch and plasticizer solids level of at least 400/o dry
solids (ds) basis.
2. The coating starch composition of embodiment 1, wherein said composition
contains 1
part of a starch for each 1, 1.5, 2, 2.5, 3, 3.5, or 4 parts of a plasticizer.
3. The coating composition of embodiment 1 or 2, where said plasticizer is a
non-
carbohydrate derived plasticizer, a carbohydrate derived plasticizer, or a
mixture thereof.
4. The coating composition of embodiment 3, where said non-carbohydrate
derived
plasticizer is selected from urea, glycerin/glycerol, formamide, citric acid
or other carboxylic
acids, ethylene glycol, and a mixture of any two or more of the foregoing.
5. The coating composition of embodiment 3, where said carbohydrate derived
plasticizer is
(i) a sugar; (ii) a sucrose, a starch derived syrup, a maltodextrin, a
dextrin, a sugar alcohol, or a
mixture of any two or more of the foregoing; (iii) a starch derived syrup
selected from a corn
syrup, a low sugar syrup, dextrose, or a mixture of any two or more of the
foregoing; (iv) a
maltose corn syrup or a high fructose corn syrup; or (v) a sorbitol.
6. The coating composition of embodiment 5, wherein said starch derived syrup
has a
dextrose equivalency (DE) of about 20 to about 90, about 20 to about 100,
about 40 to about 75,
about 40 to about 70, about 40 to about 44, about 49 to about 55, about 53 or
53.
7. The coating starch composition of any preceding embodiment, wherein said
plasticizer is
a corn syrup selected from maltose corn syrup, high fructose corn syrup, and a
mixture thereof
8. The coating starch composition of any preceding embodiment, wherein the
starch is a
modified starch selected from a nonionic starch, an anionic starch, an
amphoteric starch, an
etherified starch, an acetylated starch, a sulfonated starch, and a mixture of
any two or more of
the foregoing.
9. The coating starch composition of any preceding embodiment, wherein the
starch is
selected from corn starch, dent corn starch, waxy corn starch, wheat starch,
potato starch, tapioca
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starch, pea starch, sorghum starch, manioc starch, sago starch, rice starch,
and a mixture of any
two or more of the foregoing.
10. A paper coating composition comprising the coating starch composition of
any preceding
embodiment, wherein said composition contains at least about 2%, from about 2%
to about 30%,
from about 2% to about 25%, from about 2% to about 22%, or from about 2% to
about 10%
starch.
11. The paper coating composition of embodiment 10, wherein the composition
has (i) a
viscosity of less than 1200 cPs, about 100 to about 1200 cPs, about 200 to
about 1200 cps, or
about 300 to about 600cPs and a solids content of at least 40%, 45%, 50%, 55%,
60%, 65% or
70% dry solids (ds) basis, or (ii) a viscosity of about 300 to about 600 cPs
and a solids content of
at least 60% dry solids (ds) basis; and, optionally, wherein the viscosity is
measured on a
Brookfield Viscometer at 20 rpm at 18.3 C.
12. The paper coating composition of embodiment 10 or 11, wherein said
composition
contains from 2 to 20 parts of the starch and from 5 to 35 parts of the
plasticizer, from 2 to 10
parts of the starch and from 5 to 25 parts of the plasticizer, or 10 parts of
the starch and 25 parts
of the plasticizer.
13. The paper coating composition of any one of embodiments 10-12, wherein
said
composition further comprises (i) a pigment, a latex, or a mixture thereof; or
(ii) about 100 parts
pigment and about 10 to about 25 parts latex.
14. A method of manufacturing a dry-finished, coated paper or paperboard
product
comprising applying the paper coating composition of any one of embodiments 10-
13 to at least
one side of a paper or paperboard; and obtaining a dry finished, coated paper
or paperboard.
15. The method of embodiment 14, wherein no starch is applied to the paper or
paperboard
prior to or after the application of the paper coating composition.
16. The method of embodiment 14 or 15, with the proviso that the method does
not comprise
a wet stack calendering step prior to applying the paper coating composition
of any one of
embodiments 10-13.
17. The method of any one of embodiments 14-16, wherein the coating
composition is
applied to the paper or paperboard at a coater.
18. A dry-finished, coated paper or paperboard product produced from the
method of any one
of embodiments 14-17.
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19. The dry-finished, coated paper or paperboard product of embodiment 18,
wherein the
dry-finished paper or paperboard is characterized by a surface strength
equivalent to that of a
wet-finished paper or paperboard product as measured by an IGT pick and
blister test.
20. The dry-finished, coated paper or paperboard product of embodiment 19,
wherein the
dry-finished paper or paperboard is characterized by an IGT average increase
of at least 50%,
55%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70% as compared to a
dry-
finished paper or paperboard product coated with a standard coating.
21. A paper substrate comprising, on at least one surface, the paper coating
composition of
any one of embodiments 10-13.
Examples
[0058] The following examples are provided by way of illustration only and
not by way of
limitation. Those of skill in the art will readily recognize a variety of non-
critical parameters that
could be changed or modified to yield essentially the same or similar results.
The examples
should in no way be construed as limiting the scope of the present technology,
as defined by the
appended claims
Materials and Methods
[0059] Coating Starch. PEN-CO __________________________________________ 1E
L800 coating starch was obtained from Ingredion.
PEN-COTE D LV coating binder was also obtained from Ingredion. PEN-COTE L800
coating starch is a stable liquid waxy starch (Ingredion, Inc.). PEN-COTE D
LV coating
binder is a thinned starch that can be added to a coating in a dry form or,
alternatively,
rehydrated and then added to a coating (Ingredion, Inc). A viscosity reduced
hydroxypropyl
modified waxy corn starch that has been fully cooked through a jet cooker
(hereinafter "Liquid
Starch Composition A") (Ingredion, Inc.). A viscosity reduced ethylated dent
corn starch that
has been fully cooked through a jet cooker (hereinafter "Liquid Starch
Composition B")
(Ingredion, Inc.). A viscosity reduced OSA modified waxy corn starch that has
been fully
cooked through a jet cooker (hereinafter "Liquid Starch Composition C")
(Ingredion).
[0060] Plasticizers. Plasticizers used in the Examples include carbohydrate
derived
plasticizers such as: ENZOSE Brewers' Corn Syrup 55 DE or GLOBE 55 HM Corn
Syrup
having a DE of 53 ("53 DE High Maltose Corn Syrup") (Ingredion, Inc.); GLOBE
63 DE Corn
Syrup having a DE of 60-67 (Ingredion, Inc.); GLOBE Plus 18 DE maltodextrin
having a DE of
17-20 (Ingredion, Inc.); VERSASWEETTm 1526 28 DE Glucose Syrup having a DE of
26-30
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(Ingredion, Inc.); INVERTOSE HFCS 55 (Ingredion, Inc.) and INVERTOSE HFCS 42
(Ingredion, Inc.), which are high fructose corn syrups; Sucrose (Evaporated
Cane Juice from
Trader Joe's); and sorbitol (Ingredion, Inc.). Plasticizers used in the
Examples also include non-
carbohydrate derived plasticizer such as: glycerin (Fisher Scientific),
sorbitol (Ingredion, Inc.),
and urea (Alpha Aesar).
[0061] Other Components. A clay pigment and vinyl acrylic latex were also
added to the
coating compositions, either alone or in combination.
[0062] Paperboard Milling.
[0063] Procedure 1: The paperboard was produced on a multi-ply machine,
with a press
section and steam heated dryer cans. The dried paperboard was then calendered
and coated with
a rod coater to which a paper coating composition described herein was added.
The paperboard
was then coated with an airknife coater, dried, calendered again and wound up
on a reel.
[0064] Procedure 2: The paperboard was produced on a multi-ply machine,
with a press
section and steam heated dryer cans. The dried paperboard was then calendered
and coated with
a rod coater to which a paper coating composition described herein was added.
[0065] IGT Pick and Blister Test. The Tappi Classical Test Method T 514 cm-
92 was used
to assess surface strength.
EXAMPLE 1
Preparing Paper Coating Compositions
[0066] Four paper coating compositions were prepared with the ingredients
as shown in
Table 1. Coating 1, the control coating, is a standard paper coating
composition routinely used
as a coated recycled paperboard basecoat application. The control paper
coating composition
comprises 100 parts Clay, 16 parts latex, and 5 parts PEN-COTE L800 coating
starch, with a
viscosity of 680 cPs at 18.3 C. Coating 2 comprises 100 parts Clay, 16 parts
latex, 5 parts PEN-
COTE L800 coating starch, and 30 parts 53 DE High Maltose Corn Syrup, with a
viscosity of
160 cPs at 18.3 C. Coating 3 comprises 100 parts Clay, 16 parts latex, 35
parts PEN-COTE D
LV coating binder (a thinned coating starch), with a viscosity of 1480 cPs at
18.3 'C. Coating 4,
the "high starch coating," comprises 100 parts Clay, 16 parts latex, 10 parts
PEN-COTE L800
starch, and 25 parts 53 DE High Maltose Corn Syrup, with a viscosity of 560
cPs at 18.3 C. All
coating parts were added based on dry solids weight (parts is the standard
convention for
paperboard coatings where the pigment portion makes up 100 parts and all the
other materials
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are additive). Viscosity was measured using the Brookfield viscosity test. The
test allows for a
variety of RPMs to be employed. Viscosity measurements were performed at 20
RPMs.
Table 1: Paper Coating Compositions
Coating Temp Viscosity
Coating Components
Solids (%) ( C) (cPs)
parts PEN-COTE L800 coating starch
1
100 parts Clay 62.0 18.3
680
Control
16 parts Latex
5 parts PEN-COTE' ) L800 coating starch
100 parts Clay
2 60.7 18.3 160
16 parts Latex
30 parts 53 DE High-Maltose Corn Syrup
35 parts PEN-COTE D LV coating binder
3 100 parts Clay 62.0 18.3
1480
16 parts Latex
parts PEN-COTE L800 coating starch
4
High Starch 100 parts Clay
63.2 18.3 560
ng 16 parts Latex
Coati
25 parts 53 DE High-Maltose Corn Syrup
[0067] The data presented in Table 1 shows that the addition of 30 parts of
53 DE High-
Maltose Corn Syrup decreases the viscosity of the standard ("Control") starch
coating by more
than 75 /0 (coating 2). Increasing the starch content of coating 3 to achieve
a similar coating
solids content as for coatings 1, 2, and 4, results in the composition
becoming too viscous. The
data also shows that, with the addition of 25 parts of 53 DE High-Maltose Corn
Syrup, the
amount of PEN-COTE L800 coating starch in the composition can be doubled from
5 parts to
10 parts (coating 4), while still producing a coating with an acceptable
viscosity.
EXAMPLE 2
The High Starch Paper Coating Composition of the Present Technology Enables
Production of a Dry Finish Board with Strength Characteristics Similar to
Those of a Wet
Finish Board
[0068] A trial was run on a pilot coater in accordance with the Paper Board
Milling,
Procedure 1 set forth hereinabove. Wet finished uncoated board and dry
finished uncoated board
were used as the substrates. A wet finished uncoated board was rod coated with
Coating 1 set
forth in Table 1. The wet finish board was produced by adding starch to the
wet stack calender
prior to the coaters. A first dry finished board was rod coated with Coating 1
set forth in Table 1.
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A second dry finished board was rod coated with the high starch containing
coating of Coating 4
set forth in Table 1. The dry finish board was produced without adding starch
to the wet stack
calender prior to the coaters. All 3 boards were subsequently top coated with
a control airknife
topcoat. The boards were calendered after coatings applied and then tested.
Coatings 1 and 4
from Table 1 were applied on a 2.5 lbs/msf (12.21 grams/m2) base sheet for
each test group.
[0069] As shown in Table 2, the high starch coating (coating 4) had an IGT
average increase
of 63%, as compared to the standard coating (coating 1) on the dry finished
board. In addition,
the dry finished boards coated with the high starch coating (coating 4)
exhibited on average a
slightly higher blister IGT than the standard coating (coating 1) on a wet
finished paperboard.
Table 2: IGT Results For Wet Finish And Dry Finish Boards Using Standard And
High
Starch Coatings
Wet Finish-Standard Dry Finish-Standard
Dry Finish-High Starch
Coating (Coating 1, Table Coating (Coating 1, Table 1) Coating (Coating 4,
Table 1)
1)
IGT IGT IGT
Pick Blister Pick Blister Pick
Blister
(ICPCMS) (ICPCMS) (ICPCMS) (KPCMS) (ICPCMS) (ICPCMS)
71 56 39 38 74 78
73 76 43 46 68 70
76 66 46 45 66 76
Avg. = 73.3 Avg. = 66 Avg. =43 Avg. =43 Avg. = 69
Avg. = 75
[0070] These
results demonstrate that the paper coating compositions described herein
provide an improved method for manufacturing paperboard. As demonstrated
herein, the use of
a high starch coating compositions described herein in a dry finished board
coating process
confers strength and quality characteristics comparable to those resulting
from the use of a
standard starch coating composition in a wet finished board coating process.
Surprisingly, the
addition of maltose corn syrup to a paper coating composition (coating 4)
reduced the viscosity
of the coating and allowed more starch to be added to the paper coating
composition, thereby
enabling the production of a paper coating composition with a higher starch
solids content. The
higher starch solids content of the paper coating composition enabled the wet
stack calender to
be eliminated from the paper coating process, thereby decreasing manufacturing
time and costs
associated therewith. As illustrated in Table 1, the starch content can be
doubled (from 5 parts to
parts) while producing a coating that has a lower viscosity than a standard
coating (coating 1).
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[0071] Accordingly, these results demonstrate that the paper coating
compositions described
herein permit for elimination of a wet stack calender step in the paper
manufacturing process.
Ordinarily, if the wet stack calender step is removed from the process, the
amount of starch
applied to the paperboard at the rod coater must be increased. However, for
practical purposes,
the additional starch that must be added at the coater when the wet stack
calender is removed
cannot increase the viscosity of the coating. As shown herein, the
compositions of the present
technology enable additional starch to be added to the paper coating
compositions applied via the
rod coaters without increasing the viscosity, thereby permitting the
elimination of the wet stack
calendering step without compromising the strength and quality of the finished
paperboard
product.
EXAMPLE 3
Preparing Paper Coating Compositions Containing a Variety of Starch Derived
Syrups
and Testing Strength Characteristics
[0072] Additional paper coating compositions were prepared with the
ingredients as shown
in Table 3. The coating 5 control composition is a standard paper coating
composition routinely
used as a basecoat to coat recycled paperboard. The coating 5-22 compositions
are coatings
compositions prepared in accordance with the present invention with a variety
of starch derived
syrups. All coating parts were added based on dry solids weight (parts is the
standard
convention for paperboard coatings where the pigment portion makes up 100
parts and all the
other materials are additive) using an overhead mixer. Viscosity was measured
using the
Brookfield viscosity test. The test allows for a variety of RPMs to be
employed. Viscosity
measurements were performed at a temperature of 23.9 C using spindle 4 at 20
RPMs. The
solids content of the coating 5-16 and 19-22 compositions was measured using a
moisture
balance (available from Mettler-Toledo Ltd., Beaumont Ley, Leicester, UK). The
solids content
of the coating 17-18 compositions was calculated based on the solids content
of the ingredients
used as measured or provided by the manufacturer.
[0073] Each coating 5-22 composition was coated on a dry finished board in
accordance with
the Paper Board Milling, Procedure 2 set forth hereinabove using a hand
drawdown process
using a rod. None of the boards were subsequently top coated.
[0074] Each of the Table 3 coating 6-22 compositions exhibited a lower
viscosity in
combination with improved strength characteristics than the coating 5 control
composition.
23
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Table 3: Additional Paper Coating Compositions & Associated Strength
Characteristics
F IGT
rl)
alo el II
c= ,---,
Coating Components
;43
g
.õ
L)a
5 parts PEN-COTE L800 coating starch
100 parts Clay 62.1 23.9 1420 22
19
Control
16 parts Latex
5 parts PEN-COTE" L800 coating starch
100 parts Clay
6 61.6 23.9 1040 28 24
16 parts Latex
parts GLOBE R( Plus 18 DE Maltodextrin
3 parts PEN-COTE L800 coating starch
100 parts Clay
7 62.0 23.9 650 24
19
16 parts Latex
12 parts GLOBE Plus 18 DE Maltodextrin
5 parts PEN-COTE L800 coating starch
100 parts Clay
8 16 parts Latex 61.7 23.9 1000 35 22
10 parts VERSASWEET" 1526 28 DE Glucose
Syrup
5 parts PEN-CO IF L800 coating starch
100 parts Clay
9 61.5 23.9 620 24
20
16 parts Latex
10 parts ENZOSE Brewers' Corn Syrup 55DE
3 parts PEN-00 1E L800 coating starch
100 parts Clay
10 62.0 23.9 550 30 24
16 parts Latex
12 parts ENZOSE Brewers Corn Syrup 55DE
5 parts PEN-00 1E L800 coating starch
100 parts Clay
11 61.7 23.9 720 31
22
16 parts Latex
10 parts INVERTOSE HFCS 55
3 parts PEN-CO 1E L800 coating starch
100 parts Clay
12 61.7 23.9 390 29
22
16 parts Latex
12 parts INVERTOSE HFCS 55
5 parts PEN-CO 1E L800 coating starch
100 parts Clay
13 61.8 23.9 660 27
21
16 parts Latex
10 parts INVERTOSE HFCS 42
24
CA 03129837 2021-08-10
WO 2020/172400 PCT/US2020/019027
Table 3: Additional Paper Coating Compositions & Associated Strength
Characteristics
IGT
'4 17
---
Coating Components :7)
E g
g 4 .1
(.5
3 parts PEN-COTE L800 coating starch
100 parts Clay
14 61.9 23.9 520 27 26
16 parts Latex
12 parts INVERTOSE I-IFCS 42
parts PEN-COTE L800 coating starch
100 parts Clay
61.6 23.9 840 27 23
16 parts Latex
10 parts GLOBE 63 DE Corn Syrup
3 parts PEN-COTE L800 coating starch
100 parts Clay
16 61.9 23.9 700 31 27
16 parts Latex
12 parts GLOBE 63 DE Corn Syrup
5 parts PEN-COTE L800 coating starch
100 parts Clay
17 62 23.9 600 27 34
16 parts Latex
10 parts Glycerin
3 parts PEN-COTE L800 coating starch
100 parts Clay
18 62 23.9 450 27 23
16 parts Latex
12 parts Glycerin
5 parts PEN-COTE L800 coating starch
100 parts Clay
19 62.0 23.9 670 27 21
16 parts Latex
10 parts sucrose
3 parts PEN-COTE L800 coating starch
100 parts Clay
62.0 23.9 490 26 19
16 parts Latex
12 parts sucrose
5 parts PEN-CO 1'E L800 coating starch
100 parts Clay
21 61.6 23.9 720 32 28
16 parts Latex
10 parts sorbitol
3 parts PEN-COTE L800 coating starch
100 parts Clay
22 61.9 23.9 520 28 28
16 parts Latex
12 parts sorbitol
CA 03129837 2021-08-10
WO 2020/172400 PCT/US2020/019027
EXAMPLE 4
PREPARING PAPER COATING COMPOSITIONS CONTAINING A VARIETY OF
STARCHES AND TESTING STRENGTH CHARACTERISTICS
[0075] Additional paper coating compositions were prepared with the
ingredients as shown
in Table 4. The coating 23 control composition is a standard paper coating
composition
routinely used as a basecoat to coat recycled paperboard. The coating 24-31
compositions are
coating compositions prepared in accordance with the present invention with a
variety of
starches. All coating parts were added based on dry solids weight (parts is
the standard
convention for paperboard coatings where the pigment portion makes up 100
parts and all the
other materials are additive) using an overhead mixer. Viscosity was measured
using the
Brookfield viscosity test. The test allows for a variety of RPMs to be
employed. Viscosity
measurements were performed at a temperature of 23.9 C using spindle 4 at 20
RPMs. The
solids content of the coating 23-31 compositions was measured using a moisture
balance
(available from Mettler-Toledo Ltd., Beaumont Ley, Leicester, UK).
[0076] Each coating 23-31 composition was coated on a dry finished board in
accordance
with the Paper Board Milling, Procedure 2 set forth hereinabove using a hand
drawdown process
using a rod. None of the boards were subsequently top coated.
[0077] Each of the Table 4 coating compositions 24-31 exhibited a lower
viscosity in
combination with improved strength characteristics than the coating 23 control
composition.
26
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Table 4: Additional Paper Coating Compositions & Associated Strength
Characteristics
i=-= IGT
;-7µ
^ II II
E'Z'
E7)
¨ 0
¨
Coating Components (,)
.rg
Eli' s-
et:
parts PEN-COTE L800 coating starch
23
100 parts Clay 62.1 23.9 1420 22 19
Control
16 parts Latex
5 parts Liquid Starch Composition A
100 parts Clay
24 61.3
23.9 880 29 26
16 parts Latex
parts urea
3 parts Liquid Starch Composition A
100 parts Clay
25 61.4
23.9 520 26 22
16 parts Latex
12 parts urea
5 parts Liquid Starch Composition A
100 parts Clay
26 62.1 23.9 1180 28 25
16 parts Latex
10 parts ENZOSE Brewers' Corn Syrup 55DE
3 parts Liquid Starch Composition A
100 parts Clay
27 62.0
23.9 830 30 29
16 parts Latex
12 parts ENZOSE Brewers' Corn Syrup 55DE
5 parts Liquid Starch Composition B
100 parts Clay 62.0
28 23.9 1080 30 30
16 parts Latex
10 parts ENZOSE Brewers' Corn Syrup 55DE
3 parts Liquid Starch Composition B
100 parts Clay
29 62.2
23.9 640 31 28
16 parts Latex
12 parts ENZOSE Brewers' Corn Syrup 55DE
5 parts Liquid Starch Composition C
100 parts Clay
30 62.8 23.9 1350 31 26
16 parts Latex
10 parts ENZOSE Brewers' Corn Syrup 55DE
3 parts Liquid Starch Composition C
100 parts Clay
31 62.2
23.9 750 33 26
16 parts Latex
12 parts ENZOSE Brewers' Corn Syrup 55DE
27
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EXAMPLE 5
PAPER COATING COMPOSITION HAS IMPROVED SURFACE STRENGTH
CHARACTERISTICS WITHOUT SACRIFICING OTHER PHYSICAL
CHARACTERISTICS
[0078] Paper coating compositions were prepared with the ingredients as
shown in Table 5.
The coating 32 control composition is a standard paper coating composition
routinely used as a
basecoat to coat recycled paperboard. The coating 33 composition was prepared
in accordance
with the present invention. All coating parts were added based on dry solids
weight (parts is the
standard convention for paperboard coatings where the clay portion makes up
100 parts and all
the other materials are additive) using an overhead mixer.
[0079] Each coating 32-33 composition was coated on a dry finished board in
accordance
with the Paper Board Milling, Procedure 2 set forth hereinabove using a hand
drawdown process
using a rod. None of the boards were subsequently top coated. For Tables 5 and
6, the surface
and physical characteristics of the coated paper boards were measured at least
three times and
reported as an average ("Avg") measurement.
Table 5: Additional Paper Coating Compositions & Associated Strength
Characteristics
IGT
CA
Al
c-0 AI
cif)
oir)
Coating Components 3,)
c.,
32 100 parts Clay
54.0 25 125 38.2 24.2
Control 21 parts Latex
9 parts PEN-COTE L800 coating starch
33 9 parts ENZOSE brewers corn syrup 55DE
54.0 25 157 59.67 24
High Starch 100 parts Clay
18 parts Latex
[0080] The data shown in Tables 5 and 6 show that adding the coating starch
and plasticizer
and decreasing the ratio of starch to pigment from 4.8:1 in Coating 32
("Control") to a ratio of
2.9:1 while leaving the coating solids percentage unchanged (Coating 33),
resulted in a slight
increase in the viscosity that was coupled to a surprising improvement in
surface strength
characteristics. The average IGT Pick value increased by more than 56%, while
the average IGT
Blister value increased by more than 97%. The data in Table 6 further shows
that the high starch
28
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33 composition displayed a significant improvement in surface strength
characteristics without
suffering a loss in the quality of the basis weight, caliper, base coat
weight, coated brightness,
Appearance DAV2, Appearance DMM, or Sheffield smoothness. The physical
characteristics
related to the weight, thickness, and appearance of the coated paper surface
remained unchanged
or substantially unchanged, when comparing the coating 32 control composition
and high starch
33 composition applied to paper boards.
Table 6: Physical Characteristics of Additional Paper Coating Compositions
w, c..) IGT
:
Go
wl
....-
.., .
..,1 ..,)
am c)
ca .ot a.
.* wl
a == X a)
..'t ..: Z cA A A 0 ttk CZ'
t>I) "C17
>
Coating 2 u
GO 60
C.0 'IS
c .4.' x "
X
c,f:),
. _
E c.= .:t
ti..)
ct 6.
ct cA
4,-, 00 ......, E .....
vg l 'cli 'cl 4.-.
0.)
act
v)
32 65.8 18.1 1.4 79.8 58.1 27.9 153.2 125 38.2 24.2
Control
33
65.8 18.1 1.5 79.0 58.3 27.8 156.7 157 59.7 37.6
High Starch
[0081]
The present technology is not to be limited in terms of the particular
embodiments
described in this application, which are intended as single illustrations of
individual aspects of
the present technology. Many modifications and variations of this present
technology can be
made without departing from its spirit and scope, as will be apparent to those
skilled in the art.
Functionally equivalent methods and apparatuses within the scope of the
present technology, in
addition to those enumerated herein, will be apparent to those skilled in the
art from the
foregoing descriptions. Such modifications and variations are intended to fall
within the scope
of the appended claims. The present technology is to be limited only by the
terms of the
appended claims, along with the full scope of equivalents to which such claims
are entitled. It is
to be understood that this present technology is not limited to particular
methods, reagents,
compounds compositions or biological systems, which can, of course, vary. It
is also to be
understood that the terminology used herein is for the purpose of describing
particular
embodiments only, and is not intended to be limiting.
29
[0082] In addition, where features or aspects of the disclosure are
described in terms of
Markush groups, those skilled in the art will recognize that the disclosure is
also thereby
described in terms of any individual member or subgroup of members of the
Markush group.
[0083] As will be understood by one skilled in the art., for any and all
purposes, particularly
in terms of providing a written description, all ranges disclosed herein also
encompass any and
all possible subranges and combinations of subranges thereof. Any listed range
can be easily
recognized as sufficiently describing and enabling the same range being broken
down into at
least equal halves, thirds, quarters, fifths, tenths, etc. As a nonlimiting
example, each range
discussed herein can be readily broken down into a lower third, middle third
and upper third, etc.
As will also be understood by one skilled in the art all language such as "up
to," "at least,"
"greater than," "less than," and the like, include the number recited and
refer to ranges which can
be subsequently broken down into subranges as discussed above. Finally, as
will be understood
by one skilled in the art, a range includes each individual member. Thus, for
example, a group
having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group
having 1-5 cells refers
to groups having 1, 2, 3, 4, or 5 cells, and so forth.
Date Recue/Date Received 2023-03-07
