U.S. patent application number 14/049346 was filed with the patent office on 2014-04-17 for paper with higher oil repellency.
This patent application is currently assigned to Georgia-Pacific Chemicals LLC. The applicant listed for this patent is Georgia-Pacific Chemicals LLC. Invention is credited to Cornel Hagiopol, James W. Johnston, Charles G. Ruffner, Lakeisha D. Talbert, David F. Townsend.
Application Number | 20140106165 14/049346 |
Document ID | / |
Family ID | 50475580 |
Filed Date | 2014-04-17 |
United States Patent
Application |
20140106165 |
Kind Code |
A1 |
Johnston; James W. ; et
al. |
April 17, 2014 |
PAPER WITH HIGHER OIL REPELLENCY
Abstract
This disclosure provides for a process for making an oil and
grease resistant cellulosic material such as paper and paperboard,
the process comprising applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate, and subsequently
drying the treated cellulosic substrate to form an oil repellent
cellulosic material. Fluorochemicals that can be used to modify the
nanoparticles include fluoroalkylsilanes, ionic fluorochemicals, or
fluorinated polyacrylate obtained by seeded emulsion polymerization
of fluorinated acrylates on the nanoparticles. Paper, paperboard
and cellulose fiber articles that have been modified by the
disclosed processes have improved oil and grease resistance
properties.
Inventors: |
Johnston; James W.;
(Suwanee, GA) ; Townsend; David F.; (Grayson,
GA) ; Hagiopol; Cornel; (Lilburn, GA) ;
Talbert; Lakeisha D.; (Union City, GA) ; Ruffner;
Charles G.; (Kingston, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Georgia-Pacific Chemicals LLC |
Atlanta |
GA |
US |
|
|
Assignee: |
Georgia-Pacific Chemicals
LLC
Atlanta
GA
|
Family ID: |
50475580 |
Appl. No.: |
14/049346 |
Filed: |
October 9, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61713354 |
Oct 12, 2012 |
|
|
|
Current U.S.
Class: |
428/342 ;
427/394; 427/395; 427/396; 428/532; 428/537.5 |
Current CPC
Class: |
Y10T 428/277 20150115;
D21H 19/12 20130101; D21H 27/00 20130101; D21H 19/20 20130101; D21H
21/16 20130101; Y10T 428/31993 20150401; Y10T 428/31971
20150401 |
Class at
Publication: |
428/342 ;
427/394; 427/395; 427/396; 428/537.5; 428/532 |
International
Class: |
D21H 19/12 20060101
D21H019/12 |
Claims
1. A process for making an oil repellent cellulosic material, the
process comprising: a) applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate; and b) drying the
treated cellulosic substrate to form an oil repellent cellulosic
material.
2. The process of claim 1, wherein the fluorochemical comprises at
least one fluoroalkylsilane, ionic fluorochemical, or fluorinated
polyacrylate.
3. The process of claim 2, wherein the at least one
fluoroalkylsilane has the formula
[F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p, wherein: n
is 2, 3, or 4; m is 4-p; p is 1, 2, or 3; and R is a
C.sub.1-C.sub.6 hydrocarbyl or --C(O)R.sup.1 wherein R.sup.1 is
independently a C.sub.1-C.sub.6 hydrocarbyl.
4. The process of claim 2, wherein the at least one ionic
fluorochemical is selected from an amine, a polyamine, a quaternary
ammonium salt, a cationic fluorochemical comprising azetidinium
groups, or a combination thereof.
5. The process of claim 2, wherein the at least one ionic
fluorochemical is prepared from the reaction of an epihalohydrin
with a compound of the formula:
Z--(X).sub.y--C(O)--NH[(CH.sub.2).sub.m--NH].sub.n--C(O)--(X).s-
ub.y--Z, wherein Z in each occurrence is selected from an acyclic
group C.sub.sF.sub.(2s+1) wherein s is an integer from 3 to 20, and
a cyclic group C.sub.tF.sub.(2t-1) wherein t is an integer from 4
to 6; X in each occurrence is selected from (CH.sub.2).sub.p
wherein p is an integer from 2 to 14, cycloaliphatic radicals,
bridged cycloaliphatic radicals,
--CH.dbd.CH--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.dbd.CH--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--
radicals, where b is zero or an integer of from 1 to 14, and
--SO.sub.2--N(R)--(CH.sub.2).sub.q-- radicals, wherein R is an
alkyl radical containing from 1 to 6 carbon atoms and q is an
integer of from 2 to 12; y in each occurrence is 0 or 1; m is an
integer of from 2 to 6; and n is an integer of from 2 to 100.
6. The process of claim 2, wherein the ionic fluorochemicals are
anionic compounds retained on the nanoparticles with an
intermediate cationic polymer.
7. The process of claim 1, wherein the fluorochemical
surface-modified nanoparticles comprise non-fluorinated alkylsilyl
moieties having the formula [H(CH.sub.2).sub.x].sub.ySi(O--).sub.z,
wherein: x is an integer from 1 to 12; y is 4-z; and z is 1, 2, or
3.
8. The process of claim 1, wherein the cellulosic substrate
comprises a component selected from paper, paperboard, and
cellulose fiber.
9. The process of claim 1, wherein the fluorochemical
surface-modified nanoparticles form a layered structure on the
cellulosic substrate having a thickness of less than about 10,000
nanometers.
10. The process of claim 1, wherein the nanoparticle comprises
silica, titania, zirconia, layered magnesium silicate,
aluminosilicate, natural clay, synthetic clay, polystyrene, styrene
acrylonitrile (SAN), or combinations thereof.
11. The process of claim 1, wherein the nanoparticle comprises at
least one clay selected from smectites, kaolins, illites,
chlorites, attapulgites, sepiolites, or combinations thereof.
12. The process of claim 1, wherein the nanoparticle comprises
montmorillonite, bentonite, pyrophyllite, hectorite, saponite,
sauconite, nontronite, talc, beidellite, volchonskoite,
vermiculite, kaolinite, dickite, halloysite, nacrite, antigorite,
illite anauxite, indellite, chrysotile, bravaisite, suscovite,
paragonite, biotite, corrensite, penninite, donbassite, sudoite,
pennine, sepiolite, polygorskyte, clinochlore, chamosite, nimite,
pennantite muscovite, phlogopite, synthetic hectorite, or
phengite.
13. The process of claim 1, wherein the fluorochemical
surface-modified nanoparticles are present in the aqueous
dispersion at a concentration from about 0.01% to about 50% by
weight of the total composition.
14. The process of claim 1, wherein the homogeneous aqueous
dispersion further comprises an emulsion polymer or a fluorinated
resin emulsion.
15. The process of claim 1, wherein the aqueous dispersion of
fluorochemical surface-modified nanoparticles further comprises a
wetting agent, an anti-soil agent, an anti-stain agent, a
fluorochemical resin, a surfactant, a silicone, an optical
brightener, an antibacterial component, an anti-oxidant stabilizer,
a coloring agent, a light stabilizer, a UV absorber, starch,
polyvinyl alcohol, a retention aid, a wet strength aid, an
alkylated inorganic nanoparticle having no fluorine content. or any
combination thereof.
16. A paper or paperboard made according to the process of claim
1.
17. An article comprising an oil repellent cellulosic material made
by a process comprising: a) applying a homogeneous aqueous
dispersion of fluorochemical surface-modified nanoparticles to a
cellulosic substrate to form a treated cellulosic substrate; and b)
drying the treated cellulosic substrate to form an oil repellent
cellulosic material.
18. The article of claim 17, wherein the concentration of fluorine
on the oil repellent cellulosic material is either from about 10
ppm to about 500 ppm by weight (w/w), or from about 0.0001% to
about 0.10% by weight.
19. The article of claim 17, wherein the fluorochemical
surface-modified nanoparticles are present on the oil repellent
cellulosic material at a concentration of either from about 0.01%
to about 2.0% by weight, or from about 0.01 to about 3 grams per
square meter (g/m.sup.2) of surface area of the oil repellent
cellulosic material.
20. A paper or paperboard treated with a homogeneous aqueous
dispersion comprising fluorochemical surface-modified nanoparticles
to form an oil-repellent paper or paperboard.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 61/713,354, filed Oct. 12, 2012, the
disclosure of which is incorporated by reference herein in its
entirety.
TECHNICAL FIELD
[0002] The invention relates to oil and grease resistant/repellent
paper and methods for making oil and grease resistant paper.
BACKGROUND OF THE INVENTION
[0003] Paper is a composite material containing small,
interconnected discrete fibers, which provides a highly porous
structure. Paper typically is made from cellulose fibers, which are
usually formed into a sheet on a fine screen from a dilute water
suspension or slurry, so that it incorporates randomly distributed
fibers and air voids. For example, the specific area of paper can
be about 0.5-10 m.sup.2/g, in which the voids represent 25-70% of
the paper volume, which leads to an apparent density of paper of
less than about 0.8 g/cm.sup.3.
[0004] Just as paper products made from untreated cellulose fibers
that become wet lose their strength rapidly due to water
penetration, the porous structure of paper can also lead to its
penetration by oil, grease, organic solvents, and the like.
Conventionally, materials such as waxes, silicones, or
fluorochemicals have been applied topically to cellulose fiber
products to provide some measure of oil and grease resistance.
However, environmental and health concerns about C8 telomer-based
water and oil repellent products used in conventional
fluorochemical treatments has required converting the C8 telomer
fluorochemicals to C6 telomer and perfluoropolyether (PFPE)
fluorochemicals, which are thought to have lower risk of
degradation into products harmful to the environment. These latter
fluorochemicals are somewhat less efficient at oil and grease
resistance, and the conversion process itself is inefficient,
costly, and time-consuming.
[0005] Therefore, there is a continuing need in the art for
improved methods and compositions for imparting oil and grease
resistance to paper and paper products, particularly those that
involve the use of lower concentrations of fluorochemicals for
environmental and cost improvements. Also it is desirable to
further extend the effectiveness of fluorochemicals and to produce
a paper or paperboard or cellulose fiber product with improved
stiffness, print clarity, adhesion, release and friction
characteristics while still retaining desirable oil and grease
repellency and holdout attributes. This need is increasing with the
increased demand for grease/oil resistant or repellent paper for
use with bakery products, pet food packaging, instant and fast
foods, and the like. Desirable methods would be applicable to a
wide range of paper products and provide more environmentally
benign manufacturing processes, while still maintaining efficient
performance for oil and grease resistance.
SUMMARY OF THE INVENTION
[0006] According to this disclosure, there is provided a process
for improving the grease- or oil-repellency of a cellulose material
such as paper or paperboard, the process comprising treating or
contacting a cellulose material with an aqueous dispersion
comprising at least one modified nanoparticle component and at
least one fluorochemical to form an oil-repellent cellulose
material. Typically, the process can comprise applying a
homogeneous aqueous dispersion of fluorochemical surface-modified
nanoparticles to a cellulosic substrate to form a treated
cellulosic substrate; and drying the treated cellulosic substrate
to form an oil repellent cellulosic material. The fluorochemical
can be selected from or can comprise at least one
fluoroalkylsilane, cationic fluorochemical, or fluorinated
polyacrylate.
[0007] In one aspect, the disclosed provides for combining in an
aqueous medium a nanoparticle component and a fluorochemical such
as a fluoroalkylsilane to form a homogeneous aqueous dispersion
comprising fluorochemical surface-modified nanoparticles, and then
contacting the homogeneous aqueous dispersion of fluorochemical
surface-modified nanoparticles with a cellulosic substrate to form
an oil repellent cellulosic material. The process can further
comprise drying or curing oil-repellent or -resistant cellulose
material once prepared. It has been discovered that the combination
of both at least one nanoparticle component and at least one
fluorochemical to form a fluorochemical surface-modified
nanoparticle provides an unexpected improvement in the
oil-repellent characteristics of the cellulose material, while
still allowing a lower overall concentration of fluorochemical to
impart the oil-repellency. Therefore, one aspect of the disclosure
is that a more environmentally benign and lower cost process using
lower concentrations of fluorochemicals may be possible, which
still provides the desired oil-repellent properties.
[0008] While not intending to be theory-bound, it is believed that
the least one nanoparticle component and at least one
fluorochemical of the type disclosed herein, and combined as
disclosed herein, work well because the inorganic nanoparticles and
the fluorochemicals are obtained in separate processes and
individually, have different affinities towards paper and
paperboard. As a result of these different affinities, a separation
can occur such that one component may penetrate the paper surface
faster than the other component. To address this issue, this
disclosure provides for the association of a fluorochemical with
the rigid nanoparticle through chemical bonds, ionic bonds or
polymerization on the inorganic/or organic seed particles, and
forming such bonds can be achieved by selecting the fluorochemical
from a fluoroalkylsilane, a cationic fluorochemical, or a
fluorinated polymer such as a fluorinated polyacrylate,
respectively. The resulting modified or functionalized particle
appears to be a type of composite material that simultaneously
delivers the fluorochemical and the nanoparticle and their
respective influences, and thereby provides a "Lotus effect". In
one aspect, these fluorochemicals may be considered as "supported"
in that they can interact with the rigid nanoparticles, depending
on the nanoparticle composition, and this combined composition is
added to the paper at the wet end, typically along with a retention
aid, and/or at the size-press. When used at the size-press, the
size-press solution contains starches or PVA, and the cellulosic
support for the particles can be paper or board, made from hard
wood and/or soft wood.
[0009] According to a further aspect, and while not intending to be
bound by theory, it is thought that the combination of at least one
nanoparticle component and at least one fluorochemical acts to
alter the paper or paperboard (cellulose material) surface geometry
and surface energy, which enhances the grease- and oil-repellency
properties. In particular, it is thought that the specific
fluorochemicals used in this process can modify the surface of the
nanoparticles in a manner that allowed them to function in a manner
that combines the useful attributes of the individual components in
a synergistic fashion. Suitable nanoparticles include inorganic
nanoparticles (such as silica, clay minerals, other inorganic
nanoparticles), organic polymer nanoparticles (polystyrene, styrene
acrylonitrile (SAN), and the like) having a glass transition
temperature (Tg) greater than 100.degree. C.; or combinations
thereof.
[0010] In an exemplary aspect, according to this disclosure, there
is provided a process for improving the grease- and oil-resistance
or grease- and oil-repellency of a cellulosic material, such as
paper, paperboard, and other cellulose-based materials, the process
comprising: a) combining in an aqueous medium a nanoparticle
component and a fluorochemical to form a homogeneous aqueous
dispersion comprising fluorochemical surface-modified
nanoparticles; and b) contacting the homogeneous aqueous dispersion
of fluorochemical surface-modified nanoparticles with a cellulosic
substrate to form an oil repellent cellulosic material. In a
further exemplary aspect, there is provided a process for making an
oil repellent cellulosic material, the process comprising: a)
applying a homogeneous aqueous dispersion of fluorochemical
surface-modified nanoparticles to a cellulosic substrate to form a
treated cellulosic substrate; and b) drying the treated cellulosic
substrate to form an oil repellent cellulosic material. When the
fluorochemical is selected from or comprises a fluoroalkylsilyl
compound, the process can comprise: [0011] a) combining in an
aqueous medium a nanoparticle component and a fluoroalkylsilane to
form a homogeneous aqueous dispersion comprising fluoroalkylsilane
surface-modified nanoparticles, the fluoroalkylsilane having the
formula:
[0011] [F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p,
wherein [0012] n is 2, 3, or 4, [0013] m is 4-p, [0014] p is 1, 2,
or 3, and [0015] R is a C.sub.1-C.sub.6 hydrocarbyl or
--C(O)R.sup.1 wherein R.sup.1 is independently a C.sub.1-C.sub.6
hydrocarbyl;
[0016] and [0017] b) contacting the homogeneous aqueous dispersion
of fluoroalkylsilyl surface-modified nanoparticles with a
cellulosic substrate to form an oil repellent cellulosic
material.
[0018] According to a further aspect of this disclosure, in order
to obtain the homogeneous aqueous dispersion of fluorochemical
surface modified nanoparticles, a process comprising the following
steps may be employed: [0019] a) combining in an aqueous medium a
nanoparticle component and a fluorochemical (for example a
fluoroalkylsilane, a cationic fluorochemical, or both) to form a
heterogeneous mixture; and [0020] b) allowing the nanoparticle
component and the fluorochemical in the heterogeneous mixture to
interact or react until the heterogeneous mixture forms a
homogeneous aqueous dispersion of fluorochemical surface-modified
nanoparticles. In this process for making an aqueous dispersion of
fluorochemical surface-modified nanoparticles, the step of
combining in an aqueous medium a nanoparticle component and a
fluorochemical can be carried out by, for example, combining an
aqueous dispersion of the nanoparticle component and the
fluorochemical.
[0021] The fluorochemicals used to surface-modify the nanoparticles
can be cationic fluorochemicals, such that ionic interactions
develop between the anionic inorganic nanoparticle and the cationic
fluorochemical. However, anionic fluorochemicals can be used as
well. For example, to use anionic fluorochemicals, the anionic
nanoparticles can be treated first with a cationic polymer, such as
polyamine, polyamidoamine, polyamidoamine epichlorohydrine (PAE),
polyDADMAC (polydiallyldimethylammonium chloride), and/or a
cationic copolymer of acrylamide. If desired, the addition of the
anionic fluorochemical to a cellulosic substrate such as paper can
be performed in one step if desired, wherein the paper can be
treated with anionic nanoparticles previously modified with a
cationic polymer and then an anionic fluorochemical. Alternatively,
the addition of the anionic fluorochemical to a cellulosic
substrate such as paper can be performed in two steps if desired,
wherein the anionic nanoparticles treated with a cationic polymer
are used to treat the paper and then the dried paper is treated in
a second step with anionic fluorochemicals.
[0022] Once the a cellulosic substrate has been treated or
contacted with a homogeneous aqueous dispersion of fluorochemical
surface-modified nanoparticles to form an oil repellent cellulosic
material, the process can further comprise curing the treated or
contacted cellulose material. It has been discovered that the
disclosed method provides an unexpected improvement in the
oil-repellent characteristics of the cellulose material, while
still allowing a lower overall concentration of fluorochemical to
impart the oil-repellency. Therefore, it appears that the at least
one nanoparticle component acts as a type of extender for the
fluorochemical such that lower, more environmentally benign, and
lower cost concentrations of fluorochemical can be used to provide
the desired oil-repellent properties.
[0023] The following detailed description and appended claims set
forth further embodiments and aspects of this disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0024] In accordance with one aspect of the disclosed composition,
certain processes have been developed in which novel nanoparticle
compositions, particularly inorganic nanoparticle compositions,
which have been surface modified by a bi-phasic reaction with
liquid fluoroalkylsilane (FAS) reagents in an aqueous medium or by
intereaction with cationic fluorochemical reagents or by contacting
or forming fluorinated polyacrylates or other polymers with or at
the nanoparticle surface, which can be used to treat a cellulosic
material and impart excellent oil-repellent properties. The aqueous
dispersions of the disclosed composition typically are monophasic,
optically transparent and stable without significant aggregation or
precipitation and with little or no additional solvents or
surfactants. In one aspect, for example, the disclosed composition
used in the treating process can comprises an aqueous dispersion of
fluoroalkylsilyl surface modified nanoparticles, wherein the
nanoparticles comprise or are selected from at least one member
selected from the group consisting of silica, titania, zirconia,
layered magnesium silicate, aluminosilicate, natural clay,
synthetic clay, polystyrene, styrene acrylonitrile (SAN), or
combinations thereof, and wherein the fluoroalkylsilyl
surface-functionalizing moiety can be described as
[F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(O--).sub.p, wherein n
is 2, 3, or 4; m is 4-p; and p is 1, 2, or 3. If desired, the
composition can further comprise an additional non-fluorinated
alkylsilyl surface-functionalizing moiety bonded to the surface of
the nanoparticle having the
formula[H(CH.sub.2).sub.x].sub.ySi(O--).sub.z, wherein x is an
integer from 1 to 12; y is 4-z; and z is 1, 2, or 3. For example,
the additional component can be methylsilyl.
[0025] According to a further aspect, articles comprising the
fluorochemical surface-modified nanoparticles are disclosed, for
example, the article can include paper, paperboard or cellulose
based articles, and the article can exhibit improved resistance to
both grease and oil. Treated paper, paperboard, and cellulose based
products also show improved stiffness, print clarity, adhesion,
release and friction characteristics over conventional
fluorochemical or silicone treated papers and paperboard and
cellulose fiber products.
[0026] According to this disclosure, there is provided a process
for making an oil repellent cellulosic material, the process
comprising: [0027] a) applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate; and [0028] b)
drying the treated cellulosic substrate to form an oil repellent
cellulosic material. The fluorochemical used in this process can
comprises at least one fluoroalkylsilane, cationic fluorochemical,
or fluorinated polyacrylate.
[0029] In a further aspect, when the fluorochemical is a
fluoroalkylsilane, there is provided a process for improving the
grease- or oil-resistance of a cellulosic material, such as paper,
paperboard, and other cellulose-based materials, the process
comprising:
[0030] a) applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate; and
[0031] b) drying the treated cellulosic substrate to form an oil
repellent cellulosic material;
wherein the fluorochemical used to modify the surface of the
nanoparticles comprises at least one fluoroalkylsilane having the
formula
[F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p,
wherein: [0032] n is 2, 3, or 4; [0033] m is 4-p; [0034] p is 1, 2,
or 3; and [0035] R is a C.sub.1-C.sub.6 hydrocarbyl or
--C(O)R.sup.1 wherein R.sup.1 is independently a C.sub.1-C.sub.6
hydrocarbyl. If the initial step of preparing the aqueous
dispersion of fluoroalkylsilyl surface-modified nanoparticles is
undertaken, the process can comprise: [0036] a) combining in an
aqueous medium a nanoparticle component and a fluoroalkylsilane to
form a homogeneous aqueous dispersion comprising fluoroalkylsilane
surface-modified nanoparticles, the fluoroalkylsilane having the
formula:
[0036] [F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p,
wherein [0037] n is 2, 3, or 4, [0038] m is 4-p, [0039] p is 1, 2,
or 3, and [0040] R is a C.sub.1-C.sub.6 hydrocarbyl or
--C(O)R.sup.1 wherein R.sup.1 is independently a C.sub.1-C.sub.6
hydrocarbyl; and [0041] b) contacting the homogeneous aqueous
dispersion of fluoroalkylsilyl surface-modified nanoparticles with
a cellulosic substrate to form an oil repellent cellulosic
material.
[0042] According to a further aspect of this disclosure, if the
step of preparing the aqueous dispersion of fluoroalkylsilyl
surface-modified nanoparticles is undertaken, the process can
comprise: [0043] a) combining in an aqueous medium a nanoparticle
component and a fluoroalkylsilane to form a heterogeneous mixture,
the fluoroalkylsilane having the formula:
[0043] [F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p,
wherein [0044] n is 2, 3, or 4, [0045] m is 4-p, [0046] p is 1, 2,
or 3, and [0047] R is a C.sub.1-C.sub.6 hydrocarbyl or
--C(O)R.sup.1 wherein R.sup.1 is independently a C.sub.1-C.sub.6
hydrocarbyl;
[0048] and [0049] b) allowing the nanoparticle component and the
fluoroalkylsilane in the heterogeneous mixture to react until the
heterogeneous mixture forms a homogeneous aqueous dispersion of
fluoroalkylsilane surface-modified nanoparticles. In this process
for making an aqueous dispersion of fluoroalkylsilyl
surface-modified nanoparticles, the step of combining in an aqueous
medium a nanoparticle component and a fluoroalkylsilane can be
carried out by, for example, combining an aqueous dispersion of the
nanoparticle component and the fluoroalkylsilane.
[0050] In yet another aspect, a modified substrate is disclosed.
The modified substrate comprises a fluorochemical surface-modified
nanoparticle on at least one surface of the substrate, wherein the
nanoparticle and the fluorochemical are as disclosed herein. If
desired, the substrate can further comprise additional
non-fluorinated moieties, such as non-fluorinated alkylsilyl
moieties also as disclosed herein. When the substrate comprises the
additional non-fluorinated alkylsilyl component moiety, such as
trimethylsilyl, the nanoparticles that work particularly well can
be selected from silica, zirconia, titania, layered magnesium
silicate, aluminosilicate, natural clay, synthetic clay and
mixtures thereof. The substrate itself a cellulose based substrate,
typically a paper or paperboard.
[0051] In a further aspect, a process of making an oil and grease
resistant cellulosic material is disclosed. The process can
comprises (i) applying an aqueous dispersion of fluorochemical
surface modified nanoparticles to the substrate, wherein the
aqueous dispersion comprises at least one of silica, titania,
zirconia, layered magnesium silicate, aluminosilicate, natural
clay, synthetic clay and mixtures; and wherein the fluorochemical
is as disclosed herein; and (ii) drying the substrate. The
fluorochemical surface modified nanoparticles can be applied either
on one or more surfaces or on the wet end so that it is in the
interior of the substrate or a combination of these.
[0052] The nanoparticle according to this disclosure, in an aspect,
can comprise silica, titania, zirconia, layered magnesium
silicates, aluminosilicates, clays and mixtures thereof, for
example the clay can be a synthetic clay such as hectorite clay. In
another aspect, a useful combination of nanoparticles for surface
modification can be, for example, a mixture of synthetic hectorite
clay and silica.
[0053] When the fluorochemical provides a fluoroalkylsilyl moiety,
such fluoroalkylsilyl moieties can be covalently bonded to the
nanoparticle surfaces. The fluorochemical surface-modified
nanoparticles, including the fluoroalkylsilyl surface-modified
nanoparticles, can be present at a concentration in the range of
from about 0.01% to about 50% by weight of the total composition of
the dispersion, for example in the range of from about 1% to about
40% by weight, including about 1% to about 8% by weight of the
total composition. In a further aspect, the fluorochemical
surface-modified nanoparticles can be present at a concentration
(by weight of the total composition of the dispersion) of about
0.01%, about 0.02%, about 0.05%, about 0.1%, about 0.2%, about
0.5%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%,
about 7%, about 8%, about 9%, about 10%, about 12%, about 15%,
about 18%, about 20%, about 25%, about 30%, about 30%, about 40%,
about 50%, or about 50%, or any range between any of these
concentrations. For example, stable aqueous dispersions of
fluorochemical surface modified nanoparticles wherein the
nanoparticles are synthetic hectorite clay can be formed at a
concentration in the range of from about 0.01% to about 12% by
weight of the total composition, including about 1% to about 8% by
weight of the total composition.
[0054] Depending on the final use and the particular cellulose
based substrate to be treated, the dispersion of the present
invention can be diluted for more efficient application or to
control the level of moisture imparted in the treatment process.
Again, depending on the nature of the substrate that is to be
treated, its intended use and the process of manufacture, other
chemistries as may be known in the art can be combined with the
aqueous dispersion of the instant invention at suitable
concentration ranges.
[0055] The composition can further comprise a fluorinated resin
emulsion, an alkylated inorganic nanoparticle having no fluorine,
and/or at least one member selected from a wetting agent,
fluorochemical resin, surfactant, silicones, optical brighteners,
antibacterial components, anti-oxidant stabilizers, coloring
agents, light stabilizers, UV absorbers, wetting agents, starch,
polyvinyl alcohol, retention aids and wet strength aids and
mixtures thereof. Optionally, the composition can be blended with
additional wetting agents, anti-soil agents, fluorochemical resins,
surfactants or mixtures thereof, as known in the art, in order to
simplify the manufacturing process at hand. While the aqueous
dispersion is generally compatible, it is naturally desirable to
avoid the addition of materials that would coalesce or precipitate
the nanoparticles or otherwise diminish efficacy or utility.
[0056] In an aspect, the disclosed dispersions are found to be
surprisingly stable and exist indefinitely at moderately high
concentrations as transparent aqueous mixtures in spite of the
intrinsically hydrophobic nature of fluorochemical modified
surfaces, such as fluoroalkylated surfaces. The compositions can be
useful to treat soft paper, paperboard and cellulose fiber
articles, either applied to one or both sides on the dry end such
as a size press or coater, or to the wet end such that the
chemistry is throughout the article, or in both the dry and wet
ends of the papermaking process, to impart several valuable
attributes. Paper, paperboard and cellulose fiber articles treated
with the various dispersions described have also been shown to have
increased oil and grease repellency.
[0057] Fluoroalkylsilyl Surface-Modified Nanoparticles. The
fluoroalkylsilanes that can be used to surface modify the
nanoparticles and provide the fluoroalkylsilyl surface-modified
nanoparticles, include but are not limited to fluoroalkylsilane
having the formula:
[F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p,
wherein [0058] n is 2, 3, or 4, [0059] m is 4-p, [0060] p is 1, 2,
or 3, and [0061] R is a C.sub.1-C.sub.6 hydrocarbyl or
--C(O)R.sup.1 wherein R.sup.1 is independently a C.sub.1-C.sub.6
hydrocarbyl.
[0062] In an aspect, there is provided a process for making and
using an aqueous dispersion of fluoroalkylsilyl surface-modified
nanoparticles, the process typically comprising: a) combining in an
aqueous medium a nanoparticle component and a fluoroalkylsilane to
form a heterogeneous mixture, and b) allowing the nanoparticle
component and the fluoroalkylsilane in the heterogeneous mixture to
react until the heterogeneous mixture forms a homogeneous aqueous
dispersion of fluoroalkylsilane surface-modified nanoparticles. In
this disclosed process, the fluoroalkylsilane surface-modified
nanoparticles can comprise fluoroalkylsilyl moieties having the
formula [F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(O--).sub.p. The
step of combining in an aqueous medium a nanoparticle component and
a fluoroalkylsilane can be carried out by preparing an aqueous
dispersion of the nanoparticle component, followed by combining or
adding the fluoroalkylsilane, as exemplified in the Examples
provided herein.
[0063] Also in this disclosed process, the step of combining in an
aqueous medium a nanoparticle component and a fluoroalkylsilane can
further comprises combining a non-fluorinated alkylsilane having
the formula:
[H(CH.sub.2).sub.x].sub.ySi(OR.sup.2).sub.z
or
[H(CH.sub.2).sub.x].sub.ySi(X).sub.z,
wherein [0064] x is an integer from 1 to 12; [0065] y is 4-z;
[0066] z is 1, 2, or 3; [0067] R.sup.2 in each occurrence is a
C.sub.1-C.sub.6 hydrocarbyl or --C(O)R.sup.3 wherein R.sup.3 is
independently a C.sub.1-C.sub.6 hydrocarbyl; and
[0068] X in each occurrence is independently halide or R.sup.2.
In this aspect, the fluoroalkylsilane surface-modified
nanoparticles can comprise non-fluorinated alkylsilyl moieties
having the formula [H(CH.sub.2).sub.x].sub.ySi(O--).sub.z or
[H(CH.sub.2).sub.x].sub.ySi(-).sub.z or [H(CH.sub.2).sub.x].sub.ySi
(O--).sub.z(--).sub.q, wherein "--" is a direct
silicon-nanoparticle bond and y+z+q is 4, along with the
fluoroalkylsilyl moieties having the formula
[F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(O--).sub.p.
[0069] According to a further aspect, this disclosure provides for
a process for making oil repellent cellulosic material, the process
comprising contacting or treating a cellulosic substrate with the
an aqueous dispersion of fluoroalkylsilyl surface-modified
nanoparticles prepared as diclosed herein. For example, there is
disclosed a process for making oil repellent cellulosic material,
the process comprising contacting a homogeneous aqueous dispersion
of fluoroalkylsilyl surface-modified nanoparticles with a
cellulosic substrate to form an oil repellent cellulosic material,
in which the aqueous dispersion of fluoroalkylsilyl
surface-modified nanoparticles is provided by combining in an
aqueous medium a nanoparticle component and a fluoroalkylsilane to
form a homogeneous aqueous dispersion comprising fluoroalkylsilane
surface-modified nanoparticles, the fluoroalkylsilane having the
formula [F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p, as
set forth herein. The step of combining in an aqueous medium a
nanoparticle component and a fluoroalkylsilane can further
comprises combining a non-fluorinated alkylsilane having the
formula [H(CH.sub.2).sub.x].sub.ySi(OR.sup.2).sub.z, as disclosed
herein.
[0070] Suitable nanoparticle components used according to this
disclosure include at least one member selected from silica,
titania, zirconia, layered magnesium silicate, aluminosilicate,
natural clay, synthetic clay and mixtures or combinations thereof.
For example, a further aspect provided is a process for making a
fluoroaklysilyl surface modified nanoparticle selected from silica,
titania, zirconia, layered magnesium silicate, aluminosilicate,
natural clay, synthetic clay, the process comprising: (i) creating
an aqueous dispersion of at least one member selected from the
group consisting of silica, titania, zirconia, layered magnesium
silicate, aluminosilicate, natural clay, synthetic clay and
mixtures thereof; (ii) adding a water immiscible fluoroalkylsilane
reagent to the aqueous dispersion to form a heterogeneous mixture
where the fluoroalkylsilane reagent is:
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSi(OR).sub.p, where n is
2, 3 or 4, p is 1, 2 or 3, m is (4-p), and R is selected from
methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and
--C(O)CH.sub.3; and (iii) mixing or stirring the heterogeneous
mixture or allowing it to stand until it forms a homogeneous
aqueous dispersion of fluoroaklysilane surface-modified
nanoparticles. In one example, the fluoroalkylsilane can be
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSi(O--R).sub.p, where n
can be 4, p can be 3 when m is 1 and R can be selected from methyl
and ethyl. In a further example, the nanoparticle can comprise
silica, titania, zirconia, layered magnesium silicates,
aluminosilicates, clays and mixtures thereof, for example the clay
can be a synthetic hectorite clay, for example a mixture can be
synthetic hectorite clay and silica. The fluoroalkylsilane moieties
can be covalently bonded to the nanoparticle surface, creating a
fluoroalkylsilyl moiety.
[0071] The process of making an oil repellent cellulosic material
also may comprise: a) applying or contacting a homogeneous aqueous
dispersion of fluorochemical surface-modified nanoparticles to a
cellulosic substrate to form a treated cellulosic substrate; and b)
drying the treated cellulosic substrate to form an oil repellent
cellulosic material, and can further comprise adding a fluorinated
resin emulsion to the aqueous dispersion prior applying the aqueous
dispersion to the cellulosic substrate. Additionally, the process
can further comprise including an alkylated inorganic nanoparticle
having no fluorine in the aqueous dispersion prior applying the
aqueous dispersion to the cellulosic substrate. Moreover, the
process can further comprise adding at least one member selected
from the group consisting of a wetting agent, anti-soil agent,
fluorochemical resin, surfactant and mixtures thereof prior
applying the aqueous dispersion. Optionally, a compound having the
formula:
[H(CH.sub.2).sub.x].sub.ySi(OR.sup.2).sub.z
or
[H(CH.sub.2).sub.x].sub.ySi(X).sub.z,
wherein [0072] x is an integer from 1 to 12; [0073] y is 4-z;
[0074] z is 1, 2, or 3; [0075] R.sup.2 in each occurrence is a
C.sub.1-C.sub.6 hydrocarbyl or --C(O)R.sup.3 wherein R.sup.3 is
independently a C.sub.1-C.sub.6 hydrocarbyl; and [0076] X in each
occurrence is independently halide or R.sup.2; can be used to
contact the nanoparticle before, during, or after contacting the
nanoparticle with the fluoroalkylsilane. That is, the compound
having the formula [H(CH.sub.2).sub.x].sub.ySi(OR.sup.2).sub.z or
[H(CH.sub.2).sub.x].sub.ySi(X).sub.z can be added at substantially
the same time or before, or after the addition of the
fluoroalkylsilane in contacting the nanoparticle. For example, X in
this optional compound can be selected from methoxy, ethoxy,
propoxy, butoxy, acetoxy, and chloride leaving groups. A
recirculation pump and static mixer may be used in the disclosed
process to further increase the interfacial contact between the
immiscible fluoroalkylsilane and nanoparticles.
[0077] Also as an example, according to embodiments, the
fluoroalkylsilane reactant used in step (ii) of the process to
create the fluoroalkylsilyl surface modified nanoparticles can be
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSi(O--R).sub.p, where n is
2, 3 or 4; where p is 1, 2 or 3; where (m+p)=4; and where R is
selected from methyl, ethyl, n-propyl, isopropyl, n-butyl,
isobutyl, and --C(O)CH.sub.3. In other embodiments, the fluoroalkyl
moiety of the alkylsilane reactant can be a perfluoroalkane of two
to four carbons in length, for example a four carbon
nanofluoroalkane (n is 4), where m is 1 and p is 3, and where R is
either methyl or ethyl. Extended perfluoroalkane chains can be used
to achieve greater degrees of hydrophobicity in treated substrates.
However, fluoroalkylsilyl reagents having perfluoroalkane chains
longer than four carbon atoms (n value greater than 4) are less
suitable for making the disclosed aqueous dispersions as the
addition of undesirable levels of solvents or surfactants would be
required to stabilize both reactants and product dispersions in the
disclosed process.
[0078] In one aspect of the disclosed process,
1,1,2,2-tetrahydro-nonafluorohexyl trimethoxysilane can be added
slowly with stirring to a 25% (w/w) aqueous dispersion of colloidal
silica (20 nm particles) with pH 9 to form a liquid-liquid emulsion
of cloudy appearance. Optionally, a recirculation pump and static
mixer can be used with or without the mechanical stirrer to
increase interfacial contact of the FAS with the colloidal silica
if desired. The fluoroalkylsilyl minor liquid phase is consumed
with stirring over a period of hours gradually reducing to a single
liquid phase dispersion that remains stable in the absence of
stirring. The resulting stable aqueous dispersion contains
dispersed silica nanoparticles that have a covalently bonded
hydrophobic layer on the particle surface, and this aqueous
dispersion is used to treat or contact the cellulosic
substrate.
[0079] In accordance with another aspect of the disclosed process,
1,1,2,2-tetrahydro-nonafluorohexyl trimethoxysilane (the "FAS" or
fluoroalkylsilyl reagent) can be used (for example, added slowly
to) a 5% (w/w) aqueous dispersion of synthetic hectorite clay
nanoparticles sold by the trade name Laponite.RTM. RDS from
Rockwood Additives Ltd. To prepare the fluoroalkylsilyl
surface-modified nanoparticle. Optionally, the dispersion of the
present invention can be blended with fluorinated resin emulsions
or with dispersions of alkylated inorganic nanoparticles having no
fluorine. For example, the dispersions of the fluoroalkyl modified
clay nanoparticles described above can be blended with an aqueous
dispersion of colloidal silica nanoparticles which have been
surface modified with methyltrimethyoxysilane (MTMS) so that the
resulting aqueous dispersion comprises two distinctly different
nanoparticles.
[0080] Also disclosed are substrates and processes for making and
using the fluoroalkylsilyl surface modified nanoparticles. The
substrate can comprise a fluoroalkylsilyl surface-modified
nanoparticle on at least one surface, wherein the nanoparticle
comprises at least one member selected from the group consisting
of: titania, zirconia, layered magnesium silicate, aluminosilicate,
natural clay, synthetic clay and mixtures thereof, and wherein the
fluoroalkylsilyl is:
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSi(O--).sub.p, where n is
2, 3 or 4, p is 1, 2 or 3, and m is (4-p). The nanoparticle of the
present invention can comprise titania, zirconia, layered magnesium
silicates, aluminosilicates, clays and mixtures thereof, for
example the clay can be a synthetic hectorite clay, for example a
mixture can be synthetic hectorite clay and zirconia.
[0081] In embodiments, the fluoroalkylsilyl surface-modified
nanoparticle can comprise
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSi(O--).sub.p, where n can
be 4, p can be 3 when m is 1, in which the fluoroalkylsilyl moiety
can be covalently bonded to the nanoparticle surface. The substrate
can have pores having an average diameter in the range of from
about 100 to about 100,000 nanometers. The fluoroalkylsilane
surface modified nanoparticle can form at least one layered
structure on the substrate, wherein the layered structure has a
thickness of about 10,000 nanometers or less, and a width and
length of about 100,000 nanometers or more. The substrate can
optionally comprise a component moiety bonded to the surface of the
nanoparticle having the formula
[H(CH.sub.2).sub.x].sub.ySi(O--).sub.z, wherein x is an integer
from 1 to 12, y is 4-z, and z is 1, 2, or 3. When the nanoparticle
comprises the optional component moiety, the nanoparticle can
include silica, titania, zirconia, layered magnesium silicates,
aluminosilicates, clays and mixtures thereof.
[0082] According to a further aspect, there is provided a process
for making an oil repellent cellulosic material, the process
comprising: a) applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate; and b) drying the
treated cellulosic substrate to form an oil repellent cellulosic
material; wherein the fluorochemical can comprise or be selected
from at least one cationic fluorochemical. In this aspect, the
ionic bonds can be formed between the anionic nanoparticles and the
cationic fluorochemicals.
[0083] Cationic Fluorochemicals. This disclosure also provides for
a process for making an oil repellent cellulosic material, the
process comprising the steps of: a) applying a homogeneous aqueous
dispersion of fluorochemical surface-modified nanoparticles (also
termed nanoparticles that are surface-modified by a fluorochemical)
to a cellulosic substrate to form a treated cellulosic substrate;
and b) drying the treated cellulosic substrate to form an oil
repellent cellulosic material, in which the fluorochemical can
comprise or can be selected from at least one cationic
fluorochemical. In this aspect, suitable cationic fluorochemicals
can comprise or be selected from compounds such as those disclosed
in GB 1,214,528, which is incorporated by reference herein in its
entirety. For example, the cationic fluorochemical can be a
fluorinated cationic polyamidoamine such as a protonated, an
alkylated, or an epoxidized amide-amine fluoro compound, resulting
from a protonation reaction, an alkylation reaction, or the
reaction of an epihalohydrin with an intermediate amide-amine
fluoro compound of the formula:
Z--(X).sub.y--C(O)--NH[(CH.sub.2).sub.m--NH].sub.nC(O)--(X).sub.y--Z,
wherein
[0084] Z is a radical selected from perfluoro alkyl radicals of the
formula C.sub.sF.sub.(2s+1), where s is an integer having a value
of from 3 to 20 inclusive, and cycloperfluoro alkyl radicals of the
formula C.sub.tF.sub.(2t-1), where t is an integer having a value
of from 4 to 6 inclusive;
[0085] X is a radical selected from straight chain alkylene
radicals of the formula (CH.sub.2).sub.p, where p is an integer
having a value of from 2 to 14 inclusive, cycloaliphatic radicals,
bridged cycloaliphatic radicals,
--CH.dbd.CH--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.dbd.CH--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--
radicals, where b is zero or an integer of from 1 to 14 inclusive
and --SO.sub.2--N(R)--(CH.sub.2).sub.q-- radicals, where R is an
alkyl radical containing from 1 to 6 carbon atoms and q is an
integer of from 2 to 12 inclusive;
[0086] y is 0 or 1;
[0087] m is an integer of from 2 to 6 inclusive;
[0088] and n is an integer of from 2 to 100 inclusive.
[0089] For example, the cationic fluorochemical can be an
epoxidized amide-amine fluoro compound, resulting from the reaction
of an epihalohydrin with the intermediate amide-amine fluoro
compound disclosed above, having the formula
Z--(X).sub.y--C(O)--NH[(CH.sub.2).sub.m--NH].sub.n--C(O)--(X).sub.y--Z.
While not intending to be bound by theory, it is thought that the
product initially resulting from the reaction between the
epihalohydrin and the fluoro intermediate described immediately
above may corresponds to the following formula:
##STR00001##
wherein:
[0090] A is a halogen radical and Z, X, y, m and n are as
previously defined. However, as the reaction proceeds, the above
described initial reaction product condenses through its epoxide
group with additional quantities of the epihalohydrin, thereby
likely assuming a more complex structure.
[0091] The intermediate amide-amine fluoro compound of the formula
Z--(X).sub.y--C(O)--NH[(CH.sub.2).sub.m--NH].sub.n--C(O)--(X).sub.y--Z
can be prepared by admixing and subsequently reacting a fluoro acid
corresponding to the formula Z--(X).sub.y--C(O)OH with at least one
polyamine of the formula H.sub.2N--[(CH.sub.2).sub.m--NH].sub.nH,
wherein Z, X, y, m and n are as previously defined.
[0092] For example, suitable cationic fluorochemicals include those
generated from perfluorooctanoic acid reacting with
tetraethylenepentamine, and then with epichlorohydrin, to provide
the cationic fluorochemical as illustrated in the following
structure:
##STR00002##
In this structure, the amide nitrogen is no longer available for
protonation. In order to have the right hydrophilic-hydrophobic
balance, more amide may be used after the fluorocarbon tail is
attached. Also as disclosed, the alkylation with fluorinated
epoxides is used to prepare the azetidinium moieties.
[0093] In one aspect, suitable fluoro carboxylic acids
(Z--(X).sub.y--C(O)OH) used to prepare the cationic amido-amine
fluoro compounds include, but are not limited to: perfluorobutanoic
acid, (C.sub.3F.sub.7COOH); perfluorooctanoic acid
(C.sub.7F.sub.15COOH); omega-perfluoroheptyl pentanoic acid
(C.sub.7F.sub.15(CH.sub.2).sub.4COOH); omega-perfluoroheptyl
undecanoic acid (C.sub.7F.sub.15(CH.sub.2).sub.10COOH);
perfluoroheptyl methyl cyclobutane carboxylic acid; perfluoroheptyl
substituted norbornene carboxylic acid;
omega-perfluoroheptyl-beta-allyloxy-propionic acid
(C.sub.7F.sub.15--CH.dbd.CHCH.sub.2--O--(CH.sub.2).sub.2COOH);
omega-perfluoroheptyl-beta-propoxypropionic acid
(C.sub.7F.sub.15--(CH.sub.2).sub.3--O--(CH.sub.2).sub.2COOH);
omegaperfluoroheptyl-beta-allylthiopropionic acid
(C.sub.7F.sub.15--CH.dbd.CHCH.sub.2--S--(CH.sub.2).sub.2COOH);
omega-perfluorohepryl-beta-propylthiopropionic acid
(C.sub.7F.sub.15--(CH.sub.2).sub.3--S--(CH.sub.2).sub.2COOH); and,
omega-(N-methyl)-perfluoroheptanesulfonamide hendecanoic acid
(C.sub.7F.sub.15--SO.sub.2--N(CH.sub.3)--(CH.sub.2).sub.10--COOH).
[0094] According to a further aspect, the polyamine compounds
applicable for use in preparing the cationic amido-amine fluoro
compounds include, but are not limited to
H.sub.2N--[(CH.sub.2).sub.m--NH].sub.4H wherein m is an integer of
from 2 to 6 inclusive and n is an integer of from 2 to 100
inclusive, and can include combinations of compounds according to
this formula. Thus, among the applicable polyamines are included:
diethylenetriamine, triethylenetetramine, tetraethylenepentamine,
and bis-hexamethylenetriamine, although these representative
compounds are only exemplary. More than one of the polyamines
corresponding to the above formula may be simultaneously utilized
in the reaction system. If desired, crude residues containing
mixtures of amines as the polyamine starting material can be
employed. Moreover, both linear and branched structures of the
polyamine are envisioned. For example, when the polyamine compound
contains two or more primary amine groups and the value of n
exceeds about 8, it is likely that the resulting polyamine will
exhibit a branched structure, such branched polyamines also being
deemed readily applicable for use according to this disclosure.
[0095] All available epihalohydrins, including epichlorohydrin and
epibromohydrin, may be utilized in accordance with this disclosure,
with epichlorohydrin being preferred for reasons of economy and
availability. Conditions under which the amide-amine fluoro
compound can be epoxidized from the reaction of an epihalohydrin
include those conditions as disclosed in GB 1,214,528, which is
incorporated by reference herein in its entirety.
[0096] Also by way of example, suitable cationic fluorochemical for
use according to this disclosure include those provided in U.S.
Pat. No. 4,344,993, which is incorporated herein by reference in
its entirety. For example, the "ionic perfluorocarbons" described
in U.S. Pat. No. 4,344,993 can be used. These ionic
perfluorocarbons that can be suitably employed include organic
compounds generally represented by the formula:
R.sub.fZ,
wherein R.sub.f is a saturated fluoroaliphatic moiety containing a
F.sub.3C-moiety and Z is a ionic moiety or a potentially ionic
moiety. The fluoroaliphatic moiety can typically contain 3 to 20
carbons wherein substantially all are fully fluorinated, preferably
from about 3 to about 10 of such carbons. This fluoroaliphatic
moiety may be linear, branched or cyclic, preferably linear, and
may contain an occasional carbon-bonded hydrogen or halogen other
than fluorine, and further may contain a divalent sulfur or oxygen
atom or a trivalent nitrogen atom bonded only to carbon atoms in
the skeletal chain. More preferred are those linear
perfluoroaliphatic moieties represented by the formula:
C.sub.nF.sub.2n+1,
wherein n can be from about 3 to about 12, for example, from 5 to
10. Ionic or potentially ionic moieties advantageously further
include those represented by the following formulas:
##STR00003##
wherein: [0097] R is hydrogen or hydrocarbyl such as lower alkyl
having 1-3 carbons; [0098] R' is hydrocarbylene or
oxyhydrocarbylene such as alkylene having 1 to 6 carbons, arylene,
oxyarylene, aralkylene or similar divalent hydrocarbon or
oxyhydrocarbon moiety; [0099] each R'' is individually hydrogen,
hydrocarbyl such as lower alkyl having 1 to 5 carbons or
hydroxyhydrocarbyl; and [0100] X.sup.- is an anion, especially an
inorganic anion such as halide, sulfate or carboxylate such as
acetate; and [0101] M.sup.+ is a cation such as an alkali metal
cation or ammonium.
[0102] For example, in one aspect, the suitable cationic
fluorochemical can be a cationic perfluorocarbon, including for
example,
3-[((heptadecylfluorooctyl)sulfonyl)amino]-N,N,N-trimethyl-1-propanaminiu-
m iodide;
3-[((heptadecylfluorooctyl)carbonyl)amino]-N,N,N-trimethyl-1-pro-
panaminium chloride, and/or a cationic perfluorocarbon sold by
duPont under the tradename Zonyl.TM. FSC. Examples of other
preferred cationic perfluorocarbons, as well as methods of
preparation, are those listed in U.S. Pat. No. 3,775,126.
[0103] Additional further examples of cationic fluorochemicals
include but are not limited to those provided in U.S. Pat. No.
6,951,962, which is incorporated herein by reference in its
entirety. For example, suitable cationic fluorochemicals include
those compounds having an oleophobic and hydrophobic fluorochemical
group, which is substituted with an alkyl chain which has a
hydrophilic group, where the fluorochemical portion of the
fluorochemical group is further characterized as a monovalent,
perfluorinated, alkyl or alkenyl, straight, branched or cyclic
organic radical having three to twenty fluorinated carbon atoms,
and which can be interrupted by divalent oxygen or sulfur atoms if
desired.
[0104] In an aspect, suitable cationic fluorochemical compounds
include those that contains both a polyamine functionality and
fluorinated groups. For example, the polyamine can provide a type
of molecular scaffolding upon which the fluorinated group and the
cationic functionality are included or assembled. The polyamine
functionality also can allow the nitrogens to be substituted with
four groups such that they have a cationic character which aids in
their function in accordance with the disclosure, for example,
allows for interaction with the negatively charged nanoparticles.
While not theory bound, the fluorinated groups included in the
cationic fluorochemical compounds may reduce the surface energy to
the point that oil and grease will not wet the cellulosic substrate
to which the homogeneous aqueous dispersion of fluorochemical
surface-modified nanoparticles is applied. Thus, the low free
surface energies are thought to make them particularly effective at
repelling low surface energy materials such as oil and grease, thus
repelling these substances from a treated substrate.
[0105] In accordance with an aspect, the cationic fluorochemical
compounds can include or be selected from those disclosed in U.S.
Pat. No. 6,951,962, which is incorporated herein by reference in
its entirety. For example, suitable cationic fluorochemicals
include those having the following structures:
##STR00004##
wherein: [0106] R.sup.8, R.sup.9, R.sup.10, R.sup.11, R.sup.12 are
selected from J, H, --(CH.sub.2).sub.1-6H,
--(CH.sub.2CH.sub.2O).sub.1-10H, --(CH.sub.2CHOH).sub.1-10CH.sub.3,
--CH(CH.sub.3)CH.sub.2OH, --CH.sub.2CH(OH)CH.sub.2Cl,
##STR00005##
[0106] --CH.sub.2CH(OH)CH.sub.2OH, --CH.sub.2CO.sub.2.sup.-M.sup.+
(M is a group 1 or 2 metal),
--(CH.sub.2).sub.1-6NH.sub.2,1,0(R.sup.8).sub.0,1,2, [0107] wherein
any two of R.sup.8, R.sup.10, R.sup.11, or R.sup.12 can be the same
carbon chain, [0108] R.sup.7 is selected from H,
--CH.sub.2CH(OH)CH.sub.2, which can be cross-linked to nitrogen on
K or L or M on a different fluoro(hydroxyl)alkyl, polyalkyl amino
halohydrin or organo sulfonate, where at least one of R.sup.8,
R.sup.9, R.sup.10, R.sup.11, R.sup.12 is a fluorochemical as
denoted by "J", and J is selected from the following moieties:
##STR00006##
[0108] wherein, according to the conventional rules of chemical
valence: [0109] A is selected from --(CH.sub.2).sub.1-9--,
--CH.sub.2 CHI(CH.sub.2).sub.1-9BCH.sub.2--,
--CH.dbd.CH(CH.sub.2).sub.1-9BCH.sub.2--,
--(CH.sub.2).sub.1-11BCH.sub.2--,
--(CH.sub.2).sub.1-2B(CH.sub.2).sub.1-10BCH.sub.2--, where B is
selected from O, CO.sub.2, CO.sub.2[(CH.sub.2).sub.1-2O].sub.1-10,
OCH.sub.2 CO.sub.2, OCH.sub.2 CO.sub.2 CO.sub.2
[(CH.sub.2).sub.1-2O].sub.1-10, S, SO.sub.2, SCH.sub.2CO.sub.2,
C(O)S, SCH.sub.2C.sub.2O[(CH.sub.2).sub.1-2O].sub.1-10,
S[(CH.sub.2).sub.1-2O].sub.1-10, S(O)NR', C(S)NR',
S(O)NR'CH.sub.2CH.sub.2O, C(O)NR', OCH.sub.2C(O)NR', OPO.sub.3,
NR', SCH.sub.2C(O)NR', --N(R)CH.sub.2CO.sub.2, where R' is selected
from H, --(CH.sub.2).sub.1-6; [0110] R is selected from H,
--(CH.sub.2).sub.1-6H; [0111] R.sub.F is selected from
F(CF.sub.2).sub.4-18, CF.sub.3CF(CF.sub.3)(CF.sub.2).sub.3-5,
CF.sub.3CF.sub.2 CF(CF.sub.3)(CF.sub.2).sub.3-5,
H(CF.sub.2).sub.4-18, HCF.sub.2CF(CF.sub.3)(CF.sub.2).sub.3-5,
HCF.sub.2CF.sub.2CF(CF.sub.3)(CF.sub.2).sub.3-5, cycloperfluoroalky
radicals of the formula C.sub.2F.sub.(2z-1) wherein z is an integer
from 4-6 inclusive; [0112] n, p, q, s, t, v, and w are integers;
[0113] p is 0 or 1; [0114] n is 1-6; [0115] v+q+w+s=an integer from
3 to about 1000; [0116] q, w, s each may be zero if desired; [0117]
t is w+s; [0118] Q is selected from Cl.sup.-, Br.sup.-, I.sup.-,
CH.sub.3C.sub.6H.sub.4SO.sub.2.sup.-, CH.sub.3SO.sub.2.sup.-, and
the like; and [0119] K, L and M are randomly distributed along the
polyamine and T is an amine on the end of the polyamine chain.
[0120] In accordance with a further aspect, the use of anionic
fluorochemicals is possible because of ionic bonds between anionic
nanoparticles and anionic fluorochemicals can be established
through an intermediate cationic polymer. For example, the anionic
nanoparticles are modified first with a cationic non-fluorinated
polymer, such as polyamines, polyamidoamines, polyamidoamine
epichlorohydrine (PAE), polyDADMAC, cationic polyacrylamide, and
combinations thereof. The anionic fluorochemicals then can be used
to form the fluiorochemical surface modified nanoparticles.
[0121] Fluorinated Emulsion Polymers. In accordance with a further
aspect, there is provided a process for making an oil repellent
cellulosic material, the process comprising: a) applying a
homogeneous aqueous dispersion of fluorochemical surface-modified
nanoparticles to a cellulosic substrate to form a treated
cellulosic substrate; and b) drying the treated cellulosic
substrate to form an oil repellent cellulosic material; wherein the
fluorochemical comprises at least one fluorinated polyacrylate. In
this aspect, the association of a fluorochemical with the rigid
nanoparticle occurs by polymerization on the nanosized seed
particles, and the resulting association of the nanoparticle with
the fluorinated polymer such as a fluorinated polyacrylate can
occur. Therefore, this seeded emulsion polymerization can be used
for the copolymerization of fluorinated acrylates and other
fluorinated monomers and co-monomers on the nanoparticles,
including along with co-monomers that are not fluorinated. In this
aspect, the nanoparticles can be surface-modified with a
fluorochemical that comprises or is selected from a polymeric
fluoro compound, such as perfluorinated polyacrylates and
perfluorinated polyurethanes (core-shell structure). In a typical
embodiment, the fluorochemical can be both an oleophobe and a
hydrophobe.
[0122] Various embodiments and aspects of this disclosure provide
that the substrate can be a paper, paperboard or cellulose fiber or
cellulose based article wherein the composition imparts the same
level of oil and grease repellency with lower levels of elemental
fluorine used compared with coatings of traditional fluorochemical
resin emulsions. Substrates coated or containing internally, or a
combination of both with the present invention have been found to
exhibit superior oil and grease repellency with less elemental
fluorine than found in coatings of traditional fluorochemical
resins. The process of making the substrate with the aqueous
dispersion of nanoparticles comprises applying the aqueous
dispersion of fluororalkylsilyl surface modified nanoparticles to a
substrate; and drying the substrate.
[0123] Also disclosed are various articles made from substrates
comprising the fluoroalkylsilyl surface-modified nanoparticles
provided in this disclosure. More specifically, an article
comprises a composition, the composition comprising the
fluoroalkylsilyl surface-modified nanoparticle described herein.
The nanoparticle can comprises at least one member selected from
the group consisting of titania, zirconia, layered magnesium
silicate, aluminosilicate, natural clay, synthetic clay and
mixtures thereof, and the fluoroalkylsilyl moiety can be as
disclosed herein. Optionally, the nanoparticle can further comprise
a non-fluorinated alkylsilyl moiety also as disclosed herein.
Articles can include but are not limited to paper, paperboard,
cellulose fiber articles, and other cellulose based articles. When
the article is paper, paperboard, cellulose fiber, or cellulose
based articles, or includes the optional non-fluorinated alkylsilyl
moieties, the nanoparticles can also include silica.
[0124] Typically and in one aspect, the articles can comprise a
total concentration of fluorine in a range of from about 10 ppm to
about 500 ppm by weight (w/w) of exposed substrate, including about
50 ppm to about 300 ppm w/w of exposed substrate. For paper,
paperboard, cellulose fiber, or cellulose based articles, the
substrate retains the fluoroalkylsilyl surface modified
nanoparticle at a weight in the range of from about 0.01% to about
2.0% by weight of the exposed substrate, including from about 0.1%
to about 1.0% by weight of the exposed substrate; or wherein the
substrate retains elemental fluorine in the range of from about
0.0001% to about 0.10% by weight of the exposed substrate,
including from about 0.0001% to about 0.010% by weight of the
exposed substrate. In embodiments, the substrate can retain
fluoroalkylsilyl surface modified nanoparticles in the range of
from about 0.01 to about 3 grams per square meter of surface area,
including from about 0.1 to about 2 grams per square meter of
surface area.
[0125] Definitions. To define more clearly the terms used herein,
the following definitions are provided, which are applicable to
this disclosure unless otherwise indicated, as long as the
definition does not render indefinite or non-enabled any claim to
which that definition is applied, for example, by failing to adhere
to the conventional rules of chemical valence. If a term is used in
this disclosure but is not specifically defined herein, the
definition from the IUPAC Compendium of Chemical Terminology,
2.sup.nd Ed(1997) can be applied, as long as that definition does
not conflict with any other disclosure or definition applied
herein, or render indefinite or non-enabled any claim to which that
definition is applied. To the extent that any definition or usage
provided by any document incorporated herein by reference conflicts
with the definition or usage provided herein, the definition or
usage provided herein controls.
[0126] While compositions and methods are described in terms of
"comprising" various components or steps, the compositions and
methods can also "consist essentially of" or "consist of" the
various components or steps.
[0127] While mostly familiar to those versed in the art, the
following definitions are provided in the interest of clarity.
[0128] As used herein, the term "nanoparticle" is used to describe
a multidimensional particle in which one of its dimensions is less
than 100 nm in length.
[0129] The abbreviation "FAS" is used to mean the class of
fluoroalkylsilane reagents used to impart fluorinated organic
functionality including, but not limited to, the inorganic
particles of this invention. FAS reagents specifically include, but
are not limited to structures of the formula:
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSi(OR).sub.p where n is 2,
3 or 4; where p is at least 1; where m is at least 1; where m+p=4;
and where, for example, R can be methyl, ethyl, n-propyl,
isopropyl, n-butyl, isobutyl, or --C(O)CH.sub.3, and the like.
Although less preferred for the process of making here disclosed,
other structures having perflourinated alkyl terminal functionality
should also be understood as being contemplated by this disclosure.
FAS reagents can also include structures of the formula:
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSi(X).sub.p where n is 2,
3 or 4; where p is at least 1; where m is at least 1; where m+p=4;
and where X is a halogen such as chlorine, bromine or iodine. FAS
reagents can also include structures of the formula:
(F(CF.sub.2).sub.nCH.sub.2CH.sub.2).sub.mSiR'.sub.p(X) where
n>2, and m+p=3, R' is methyl or ethyl bonded to the silicon atom
and where X is a halogen such as chlorine, bromine or iodine that
is bonded to the silicon atom.
[0130] The term "clay" as used herein refers to a clay mineral,
such as hydrous aluminum phyllosilicate minerals. Clay minerals
that can be used in this disclosure include 1:1 and 2:1 clays, and
can comprise, consist essentially of, or be selected from smectites
(such as montmorillonite, nontronice, sapolite, and the like),
kaolins (such as kaolinite, dickite, halloysite, nacrite, and the
like), illites (such as illite, clay-micas and the like), chlorites
(such as clinochlore, chamosite, nimite, pennantite, and the like),
and other minerals and classes such as attapulgites, sepiolites,
and the like. These classes include specific clays such as
montmorillonite, bentonite, pyrophyllite, hectorite, saponite,
sauconite, nontronite, talc, beidellite, volchonskoite,
vermiculite, kaolinite, dickite, antigorite, anauxite, indellite,
chrysotile, bravaisite, suscovite, paragonite, biotite, corrensite,
penninite, donbassite, sudoite, pennine, sepiolite, and
polygorskyte. The clay minerals of the invention may be either
synthetic or natural and are exfoliated to be capable of forming
aqueous micro dispersions. An example of one embodiment of the
present invention uses synthetic hectorite clay nanoparticles sold
by the trade name Laponite.RTM. from Rockwood Additives Ltd.
Preferred embodiments of the present invention use Laponite
RDS.RTM., Laponite JS.RTM., and Laponite RD.RTM.. Therefore, also
as used herein, the term "clay" can refer to a clay mineral, such
as hydrous aluminum phyllosilicate minerals, and can include 1:1
and 2:1 clays, and can comprise, consist essentially of, or be
selected from smectites (such as montmorillonite, nontronice,
sapolite, and the like), kaolins (such as kaolinite, dickite,
halloysite, nacrite, and the like), illites (such as illite,
clay-micas and the like), chlorites (such as clinochlore,
chamosite, nimite, pennantite, and the like), and other minerals
and classes such as attapulgites, sepiolites, and the like.
[0131] An aqueous "dispersion" means a colloidal dispersion, which
is a system of finely divided particles of small size, such as
nanoparticles, which are uniformly dispersed in a manner such that
they are not easily filtered or gravitationally separated.
[0132] An aqueous "micro dispersion" is used to describe a
dispersion of particles predominately having at least one dimension
that is less than about 100 nm in extent.
[0133] A "non-solubilized" aqueous micro dispersion is an aqueous
micro dispersion that is stable for extended periods of time (two
or more months) without water compatible surfactants.
[0134] A "layered structure" is one in which the overlap of
nanoparticles is observed, and where flat layers or sheets are
observed rather than round, globular or clumped aggregate
structures.
[0135] The term "cellulosic material" or similar terms such as
"cellulose fiber material" or "cellulose material" are typically
used to refer to paper, paperboard, and cellulose fibers at any
stage of their use, for example, being used in the preparation of
paper and paperboard.
[0136] The term "hydrocarbyl" is used herein in accordance with the
definition specified by IUPAC: a univalent group formed by removing
a hydrogen atom from a hydrocarbon (that is, a group containing
only carbon and hydrogen). Non-limiting examples of hydrocarbyl
groups include linear, branched, and cyclic hydrocarbyl groups such
as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,
cyclopentyl, vinyl, and the like.
[0137] The term "alkyl" group is used herein in accordance with the
definition specified by IUPAC: a univalent group derived from an
alkane by removal of a hydrogen atom from any carbon atom, having
the formula --C.sub.nH.sub.2n+1. Unless otherwise specified, the
alkyl can include groups derived from an alkane by removal of a
hydrogen atom from a primary, secondary, or tertiary carbon.
Therefore, unless otherwise specified, non-limiting examples of
alkyl groups include linear, branched, and cyclic alkyl groups such
as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,
sec-butyl, cyclopentyl, and the like.
[0138] Unless otherwise specified, any carbon-containing group for
which the number of carbon atoms is not specified can have,
according to proper chemical practice, 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
27, 28, 29, or 30 carbon atoms, or any range or combination of
ranges between these values. For example, unless otherwise
specified, any carbon-containing group can have from 1 to 30 carbon
atoms, from 1 to 25 carbon atoms, from 1 to 20 carbon atoms, from 1
to 15 carbon atoms, from 1 to 10 carbon atoms, or from 1 to 5
carbon atoms, and the like. Moreover, other identifiers or
qualifying terms may be utilized to indicate the presence or
absence of a particular substituent, a particular regiochemistry
and/or stereochemistry, or the presence of absence of a branched
underlying structure or backbone.
[0139] In any application before the United States Patent and
Trademark Office, the Abstract of this application is provided for
the purpose of satisfying the requirements of 37 C.F.R. .sctn.1.72
and the purpose stated in 37 C.F.R. .sctn.1.72(b) "to enable the
United States Patent and Trademark Office and the public generally
to determine quickly from a cursory inspection the nature and gist
of the technical disclosure." Therefore, the Abstract of this
application is not intended to be used to construe the scope of the
claims or to limit the scope of the subject matter that is
disclosed herein. Moreover, any headings that may be employed
herein are also not intended to be used to construe the scope of
the claims or to limit the scope of the subject matter that is
disclosed herein. Any use of the past tense to describe an example
that may otherwise be indicated as constructive or prophetic is not
intended to reflect that the constructive or prophetic example has
actually been carried out.
[0140] Applicants reserve the right to proviso out any selection,
group, element, or aspect, for example, to limit the scope of any
claim to account for a prior disclosure of which Applicants may be
unaware.
EXAMPLES
[0141] The following examples are provided to illustrate various
embodiments of the disclosure and the claims. Unless otherwise
specified, reagents were obtained from commercial sources. Standard
analytical methods can be used to characterize the
compositions.
[0142] Various TAPPI testing methods, such as TAPPI Sizing Test
Methods including but not limited to T454 om-89 Turpentine Test for
Grease Resistance of Paper, T507 cm-85 Grease resistance of
Flexible Packaging Materials, T441 om-90 Water Absorptiveness of
Sized (Non-Bibulous) Paper and Paperboard (Cobb test), UM 557
Repellency of Paper and Board to Grease, Oil and Waxes (Kit test),
can be used.
[0143] Performance Tests.
[0144] For the following performance tests, all examples were
performed using the following protocol. Paper having a basis weight
of 34 g/m.sup.2 was passed through a size-press solution for 15
seconds and dried at 105.degree. C. for 20 seconds on a drum dryer.
The dried paper was conditioned for at least 24 hours at 25.degree.
C. and 50% humidity before testing. The paper was tested by
measuring the contact angle for Castor oil as a function of time
using a Rame-Hart goniometer Model 250.
Comparative Example 1
[0145] Uncoated paper was tested by measuring the contact angle as
described and was found to exhibit an initial oil contact angle of
30 degrees. After 30 seconds contact time, the contact angle decays
down to 19 degrees. This changed reflects the strong oil absorption
into the paper.
Comparative Example 2
[0146] Paper treated in a size-press with a solution of 1%
fluorochemicals (Daikin 8112) shows an initial contact angle for
Castor oil of 60 degrees. The contact angle remains unchanged after
30 minutes.
Example 3
[0147] The same paper as in Comparative Examples 6 and 7 was
treated in size-press with a solution 0.5% of modified silica, that
is silica nanoparticles modified with silane. After drying, the
initial contact angle was determined to be 75 degrees, which
remains constant over 30 minutes.
Example 4
[0148] The same paper as in Comparative Examples 7 and 8 was
pretreated in size-press with a solution 0.4% of silica particles
modified with 0.8% cationic polymer (PAE: polyamidoamine
epichlorohydrin). After drying, the pre-coated paper was treated
with a solution 1% of the same fluorochemical (Daikin 8112). The
initial contact angle was 102 degree that remains constant over 30
minutes.
[0149] Further attributes, features, and embodiments of the present
invention can be understood by reference to the following numbered
aspects of the disclosed invention. Reference to disclosure in any
of the preceding aspects is applicable to any preceding numbered
aspect and to any combination of any number of preceding aspects,
as recognized by appropriate antecedent disclosure in any
combination of preceding aspects that can be made. The following
numbered aspects are provided:
[0150] 1. A process for making an oil repellent cellulosic
material, the process comprising:
[0151] a) applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate; and
[0152] b) drying the treated cellulosic substrate to form an oil
repellent cellulosic material.
[0153] 2. The process according to the preceding aspect, wherein
the fluorochemical comprises at least one fluoroalkylsilane, ionic
fluorochemical, or fluorinated polyacrylate.
[0154] 3. The process according to any of the preceding aspects,
wherein the at least one fluoroalkylsilane has the formula
[F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p,
wherein: [0155] n is 2, 3, or 4; [0156] m is 4-p; [0157] p is 1, 2,
or 3; and [0158] R is a C.sub.1-C.sub.6 hydrocarbyl or
--C(O)R.sup.1 wherein R.sup.1 is independently a C.sub.1-C.sub.6
hydrocarbyl.
[0159] 4. The process according to any of the preceding aspects,
wherein the at least one cationic fluorochemical is selected from
an amine, a polyamine, a quaternary ammonium salt, or a combination
thereof
[0160] 5. The process according to any of the preceding aspects,
wherein the at least one cationic fluorochemical comprises
azetidinium groups.
[0161] 6. The process according to any of the preceding aspects,
wherein the at least one cationic fluorochemical is prepared from
the reaction of an epihalohydrin with a compound of the
formula:
Z--(X).sub.y--C(O)--NH[(CH.sub.2).sub.m--NH].sub.n--C(O)--(X).sub.y--Z,
wherein [0162] Z in each occurrence is selected from an acyclic
group C.sub.sF.sub.(2s+1) wherein s is an integer from 3 to 20, and
a cyclic group C.sub.tF.sub.(2t-1) wherein t is an integer from 4
to 6; [0163] X in each occurrence is selected from (CH.sub.2).sub.p
wherein p is an integer from 2 to 14, cycloaliphatic radicals,
bridged cycloaliphatic radicals,
--CH.dbd.CH--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.dbd.CH--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--
radicals, where b is zero or an integer of from 1 to 14, and
--SO.sub.2--N(R)--(CH.sub.2).sub.q-- radicals, wherein R is an
alkyl radical containing from 1 to 6 carbon atoms and q is an
integer of from 2 to 12; [0164] y in each occurrence is 0 or 1;
[0165] m is an integer of from 2 to 6; and [0166] n is an integer
of from 2 to 100.
[0167] 7. The process according to any of the preceding aspects,
wherein the ionic fluorochemicals are anionic compounds retained on
the nanoparticles with an intermediate cationic polymer.
[0168] 8. The process according to any of the preceding aspects,
wherein the fluorinated polyacrylate is obtained by seeded emulsion
polymerization of fluorinated acrylates on the nanoparticles.
[0169] 9. The process according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles comprise
non-fluorinated alkylsilyl moieties having the formula
[H(CH.sub.2).sub.x].sub.ySi(O--).sub.z,
wherein: [0170] x is an integer from 1 to 12; [0171] y is 4-z; and
[0172] z is 1, 2, or 3.
[0173] 10. The process according to any of the preceding aspects,
wherein the cellulosic substrate comprises a component selected
from paper, paperboard, and cellulose fiber.
[0174] 11. The process according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles form a
layered structure on the cellulosic substrate having a thickness of
less than about 10,000 nanometers.
[0175] 12. The process according to any of the preceding aspects,
wherein the nanoparticle comprises silica, titania, zirconia,
layered magnesium silicate, aluminosilicate, natural clay,
synthetic clay, polystyrene, styrene acrylonitrile (SAN), or
combinations thereof
[0176] 13. The process according to any of the preceding aspects,
wherein the nanoparticle comprises silica, natural clay, or
synthetic clay.
[0177] 14. The process according to any of the preceding aspects,
wherein the nanoparticle comprises at least one clay selected from
smectites, kaolins, illites, chlorites, attapulgites, sepiolites,
or combinations thereof.
[0178] 15. The process according to any of the preceding aspects,
wherein the nanoparticle comprises montmorillonite, bentonite,
pyrophyllite, hectorite, saponite, sauconite, nontronite, talc,
beidellite, volchonskoite, vermiculite, kaolinite, dickite,
halloysite, nacrite, antigorite, illite anauxite, indellite,
chrysotile, bravaisite, suscovite, paragonite, biotite, corrensite,
penninite, donbassite, sudoite, pennine, sepiolite, polygorskyte,
clinochlore, chamosite, nimite, pennantite muscovite, phlogopite,
or phengite.
[0179] 16. The process according to any of the preceding aspects,
wherein the nanoparticle comprises synthetic hectorite.
[0180] 17. The process according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles are
present in the aqueous dispersion at a concentration from about
0.01% to about 50% by weight of the total composition.
[0181] 18. The process according to any of the preceding aspects,
wherein the homogeneous aqueous dispersion further comprises an
emulsion polymer.
[0182] 19. The process according to any of the preceding aspects,
wherein the emulsion polymer is a fluorinated resin emulsion.
[0183] 20. The process according to any of the preceding aspects,
wherein the aqueous dispersion of fluorochemical surface-modified
nanoparticles further comprises an alkylated inorganic nanoparticle
having no fluorine content.
[0184] 21. The process according to any of the preceding aspects,
wherein the aqueous dispersion of fluoroalkylsilane
surface-modified nanoparticles further comprises a wetting agent,
an anti-soil agent, an anti-stain agent, a fluorochemical resin, a
surfactant, a silicone, an optical brightener, an antibacterial
component, an anti-oxidant stabilizer, a coloring agent, a light
stabilizer, a UV absorber, starch, polyvinyl alcohol, a retention
aid, a wet strength aid, or any combination thereof
[0185] 22. An article comprising an oil repellent cellulosic
material made according to the process according to any of the
preceding aspects.
[0186] 23. The article according to any of the preceding aspect,
wherein the concentration of fluorine on the oil repellent
cellulosic material is from about 10 ppm to about 500 ppm by weight
(w/w).
[0187] 24. The article according to any of the preceding aspects,
wherein the concentration of fluorine on the oil repellent
cellulosic material is from about 0.0001% to about 0.10% by
weight.
[0188] 25. The article according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles are
present on the oil repellent cellulosic material at a concentration
from about 0.01% to about 2.0% by weight.
[0189] 26. The article according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles are
present on the oil repellent cellulosic material from about 0.01 to
about 3 grams per square meter (g/m.sup.2) of surface area of the
oil repellent cellulosic material.
[0190] 27. A paper or paperboard made according to the process
according to any of the preceding aspects.
[0191] 28. A paper or paperboard treated with a homogeneous aqueous
dispersion comprising fluorochemical surface-modified nanoparticles
to form an oil-repellent paper or paperboard.
[0192] Any suitable combinations of the above described attributes,
features, and embodiments set out in the above-numbered aspects of
the present invention are also encompssed by this disclosure.
Examples of additional aspects and combinations of the above
numbered aspects of the invention that are provided herein include,
but are not limited to, following numbered aspects:
[0193] 1. A process for making an oil repellent cellulosic
material, the process comprising:
[0194] a) applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate; and
[0195] b) drying the treated cellulosic substrate to form an oil
repellent cellulosic material.
[0196] 2. The process according to the preceding aspect, wherein
the fluorochemical comprises at least one fluoroalkylsilane, ionic
fluorochemical, or fluorinated polyacrylate.
[0197] 3. The process according to any of the preceding aspects,
wherein the at least one fluoroalkylsilane has the formula
[F(CF.sub.2).sub.nCH.sub.2CH.sub.2].sub.mSi(OR).sub.p,
wherein: [0198] n is 2, 3, or 4; [0199] m is 4-p; [0200] p is 1, 2,
or 3; and [0201] R is a C.sub.1-C.sub.6 hydrocarbyl or
--C(O)R.sup.1 wherein R.sup.1 is independently a C.sub.1-C.sub.6
hydrocarbyl.
[0202] 4. The process according to any of the preceding aspects,
wherein the at least one ionic fluorochemical is selected from an
amine, a polyamine, a quaternary ammonium salt, a cationic
fluorochemical comprising azetidinium groups, or a combination
thereof
[0203] 5. The process according to any of the preceding aspects,
wherein the at least one ionic fluorochemical is prepared from the
reaction of an epihalohydrin with a compound of the formula:
Z--(X).sub.y--C(O)--NH[(CH.sub.2).sub.m--NH].sub.n--C(O)--(X).sub.y--Z,
wherein [0204] Z in each occurrence is selected from an acyclic
group C.sub.sF.sub.(2s+1) wherein s is an integer from 3 to 20, and
a cyclic group C.sub.tF.sub.(2t-1) wherein t is an integer from 4
to 6; [0205] X in each occurrence is selected from (CH.sub.2).sub.p
wherein p is an integer from 2 to 14, cycloaliphatic radicals,
bridged cycloaliphatic radicals,
--CH.dbd.CH--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--O--(CH.sub.2).sub.2--,
--CH.dbd.CH--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--,
--CH.sub.2--CH.sub.2--(CH.sub.2).sub.b--S--(CH.sub.2).sub.2--
radicals, where b is zero or an integer of from 1 to 14, and
--SO.sub.2--N(R)--(CH.sub.2).sub.q-- radicals, wherein R is an
alkyl radical containing from 1 to 6 carbon atoms and q is an
integer of from 2 to 12; [0206] y in each occurrence is 0 or 1;
[0207] m is an integer of from 2 to 6; and [0208] n is an integer
of from 2 to 100.
[0209] 6. The process according to any of the preceding aspects,
wherein the ionic fluorochemicals are anionic compounds retained on
the nanoparticles with an intermediate cationic polymer.
[0210] 7. The process according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles comprise
non-fluorinated alkylsilyl moieties having the formula
[H(CH.sub.2).sub.x].sub.ySi(O--).sub.z,
wherein: [0211] x is an integer from 1 to 12; [0212] y is 4-z; and
[0213] z is 1, 2, or 3.
[0214] 8. The process according to any of the preceding aspects,
wherein the cellulosic substrate comprises a component selected
from paper, paperboard, and cellulose fiber.
[0215] 9. The process according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles form a
layered structure on the cellulosic substrate having a thickness of
less than about 10,000 nanometers.
[0216] 10. The process according to any of the preceding aspects,
wherein the nanoparticle comprises silica, titania, zirconia,
layered magnesium silicate, aluminosilicate, natural clay,
synthetic clay, polystyrene, styrene acrylonitrile (SAN), or
combinations thereof
[0217] 11. The process according to any of the preceding aspects,
wherein the nanoparticle comprises at least one clay selected from
smectites, kaolins, illites, chlorites, attapulgites, sepiolites,
or combinations thereof.
[0218] 12. The process according to any of the preceding aspects,
wherein the nanoparticle comprises montmorillonite, bentonite,
pyrophyllite, hectorite, saponite, sauconite, nontronite, talc,
beidellite, volchonskoite, vermiculite, kaolinite, dickite,
halloysite, nacrite, antigorite, illite anauxite, indellite,
chrysotile, bravaisite, suscovite, paragonite, biotite, corrensite,
penninite, donbassite, sudoite, pennine, sepiolite, polygorskyte,
clinochlore, chamosite, nimite, pennantite muscovite, phlogopite,
synthetic hectorite, or phengite.
[0219] 13. The process according to any of the preceding aspects,
wherein the fluorochemical surface-modified nanoparticles are
present in the aqueous dispersion at a concentration from about
0.01% to about 50% by weight of the total composition.
[0220] 14. The process according to any of the preceding aspects,
wherein the homogeneous aqueous dispersion further comprises an
emulsion polymer or a fluorinated resin emulsion.
[0221] 15. The process according to any of the preceding aspects,
wherein the aqueous dispersion of fluorochemical surface-modified
nanoparticles further comprises a wetting agent, an anti-soil
agent, an anti-stain agent, a fluorochemical resin, a surfactant, a
silicone, an optical brightener, an antibacterial component, an
anti-oxidant stabilizer, a coloring agent, a light stabilizer, a UV
absorber, starch, polyvinyl alcohol, a retention aid, a wet
strength aid, an alkylated inorganic nanoparticle having no
fluorine content. or any combination thereof.
[0222] 16. A paper or paperboard made according to any of the
preceding process aspects.
[0223] 17. An article comprising an oil repellent cellulosic
material made by a process comprising:
[0224] a) applying a homogeneous aqueous dispersion of
fluorochemical surface-modified nanoparticles to a cellulosic
substrate to form a treated cellulosic substrate; and
[0225] b) drying the treated cellulosic substrate to form an oil
repellent cellulosic material; or made according to any of the
preceding process aspects.
[0226] 18. The article made according to any of the preceding
process aspects, wherein the concentration of fluorine on the oil
repellent cellulosic material is either from about 10 ppm to about
500 ppm by weight (w/w), or from about 0.0001% to about 0.10% by
weight.
[0227] 19. The article made according to any of the preceding
process aspects, wherein the fluorochemical surface-modified
nanoparticles are present on the oil repellent cellulosic material
at a concentration of either from about 0.01% to about 2.0% by
weight, or from about 0.01 to about 3 grams per square meter
(g/m.sup.2) of surface area of the oil repellent cellulosic
material.
[0228] 20. A paper or paperboard treated with a homogeneous aqueous
dispersion comprising fluorochemical surface-modified nanoparticles
to form an oil-repellent paper or paperboard.
[0229] This invention has been described above with reference to
the various aspects of the disclosed oil repellency and methods of
making paper and paperboard having improved oil repellency. Obvious
modifications and alterations will occur to others upon reading and
understanding the proceeding detailed description. It is intended
that the invention be construed as including all such modifications
and alterations insofar as they come within the scope of the
claims.
* * * * *