U.S. patent application number 11/087413 was filed with the patent office on 2006-09-28 for perfluoropolyether urethane additives having (meth)acryl groups and hard coats.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to William D. Coggio, Naiyong Jing, Thomas P. Klun, Mark J. Pellerite, Richard J. Pokorny, Zai-Ming Qiu.
Application Number | 20060216524 11/087413 |
Document ID | / |
Family ID | 36645694 |
Filed Date | 2006-09-28 |
United States Patent
Application |
20060216524 |
Kind Code |
A1 |
Klun; Thomas P. ; et
al. |
September 28, 2006 |
Perfluoropolyether urethane additives having (meth)acryl groups and
hard coats
Abstract
Fluorocarbon- and urethane-(meth)acryl-containing additives and
hardcoats. The hardcoats are particularly useful as a surface layer
on an optical device.
Inventors: |
Klun; Thomas P.; (Lakeland,
MN) ; Jing; Naiyong; (Woodbury, MN) ; Pokorny;
Richard J.; (Maplewood, MN) ; Qiu; Zai-Ming;
(Woodbury, MN) ; Pellerite; Mark J.; (Woodbury,
MN) ; Coggio; William D.; (Hudson, WI) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
36645694 |
Appl. No.: |
11/087413 |
Filed: |
March 23, 2005 |
Current U.S.
Class: |
428/423.1 ;
528/44 |
Current CPC
Class: |
C08G 18/8175 20130101;
C09D 175/16 20130101; Y10T 428/3154 20150401; G02B 1/14 20150115;
G02B 1/105 20130101; Y10T 428/265 20150115; C08G 18/673 20130101;
C08G 18/672 20130101; C08G 18/792 20130101; C07C 235/08 20130101;
C08G 18/3802 20130101; Y10T 428/31551 20150401; C08G 18/3825
20130101; C08G 18/673 20130101; C08G 18/50 20130101 |
Class at
Publication: |
428/423.1 ;
528/044 |
International
Class: |
C08G 18/00 20060101
C08G018/00; B32B 27/40 20060101 B32B027/40 |
Claims
1. A fluorocarbon- and urethane-(meth)acryl-containing additive
comprising a perfluoropolyether urethane having a
perfluoropolyether moiety and a multi-(meth)acry terminal group and
having the formula: R.sub.i--(NHC(O)XQR.sub.f).sub.m,
--(NHC(O)OQ(A).sub.p).sub.n; wherein R.sub.i is the residue of a
multi-isocyanate; wherein X is O, S or NR, where R is H or lower
alkyl of 1 to 4 carbon atoms; wherein R.sub.f is a monovalent
perfluoropolyether moiety composed of groups comprising the
formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--, wherein each R.sub.fc
independently represents a fluorinated alkylene group having from 1
to 6 carbon atoms, each x independently represents an integer
greater than or equal to 2, and wherein d is an integer from 1 to
6; wherein Q is independently a connecting group of valency at
least 2 and is selected from the group consisting of a covalent
bond, an alkylene, an arylene, an aralkylene, an alkarylene, a
straight or branched chain or cycle-containing connecting group
optionally containing heteroatoms such as O, N, and S and
optionally a heteroatom-containing functional group such as
carbonyl or sulfonyl, and combinations thereof; and wherein A is a
(meth)acryl functional group --XC(O)C(R.sub.2).dbd.CH.sub.2, where
R.sub.2 is a lower alkyl of 1to 4 carbon atoms or H or F; m is at
least 1; n is at least 1; p is 2 to 6; m+n is 2 to 10; and in which
each unit referred to by the subscripts m and n is attached to an
R.sub.i unit.
2. The additive of claim 1, wherein said fluorocarbon- and
urethane-(meth)acryl-containing additive comprises: ##STR3##
3. A fluorocarbon- and urethane-acrylate-containing additive
comprising a perfluoropolyether-substituted urethane (meth)acryl
having the chemical formula:
R.sub.f-Q-(XC(O)NHQOC(O)C(R).dbd.CH.sub.2).sub.f: wherein R.sub.f
is a monovalent perfluoropolyether moiety composed of groups
comprising the formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--,
wherein each R.sub.fc independently represents a fluorinated
alkylene group having from 1 to 6 carbon atoms, each x
independently represents an integer greater than or equal to 2, and
wherein d is an integer from 1 to 6; wherein a is 2-15; wherein Q
is independently a connecting group of valency at least 2 and is
selected from the group consisting of a covalent bond, an alkylene,
an arylene, an aralkylene, an alkarylene, a straight or branched
chain or cycle-containing connecting group optionally containing
heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; wherein X is O or S; and
wherein f is 1-5.
4. The additive of claim 3, wherein R.sub.f is HFPO.
5. The additive of claim 3, wherein said fluorocarbon- and
urethane-acrylate-containing additive comprises:
HFPO--C(O)NHC(C.sub.2H.sub.5)(CH.sub.2OC(O)NHC.sub.2H.sub.4OC(O)C(CH.sub.-
3).dbd.CH.sub.2).sub.2, where HFPO is
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)--.
6. The additive of claim 3, wherein f is 2-5.
7. A fluorocarbon- and urethane-acrylate-containing additive
comprising one or more perfluoropolyether urethanes with
multi-(meth)acryl groups of the formula:
R.sub.i--(NHC(O)XQR.sub.f).sub.m, --(NHC(O)OQ(A).sub.p).sub.n,
--(NHC(O)XQG).sub.o, --(NCO).sub.q; wherein R.sub.i is the residue
of a multi-isocyanate; where X is O, S or NR, where R is H or lower
alkyl of 1 to 4 carbon atoms; where R.sub.f is a monovalent
perfluoropolyether moiety composed of groups comprising the
formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--, wherein each R.sub.fc
independently represents a fluorinated alkylene group having from 1
to 6 carbon atoms, each x independently represents an integer
greater than or equal to 2, and wherein d is an integer from 1 to
6; where Q is independently a connecting group of valency at least
2 and is selected from the group consisting of a covalent bond, an
alkylene, an arylene, an aralkylene, an alkarylene, a straight or
branched chain or cycle-containing connecting group optionally
containing heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; where G is selected from the
group consisting of an alkyl, an aryl, an alkaryl and an aralkyl,
wherein G optionally contains heteroatoms such as O, N, and S and
optionally has heteroatom-containing functional groups such as
carbonyl and sulfonyl and combinations of heteroatoms and
heteroatom-containing functional groups; and G optionally contains
pendant or terminal reactive groups selected from the group
consisting of (meth)acryl groups, vinyl groups, allyl groups and
--Si(OR.sub.3).sub.3 groups, where R.sub.3 is a lower alkyl of 1 to
4 carbon atoms, wherein G also optionally has fluoroalkyl or
perfluoroalkyl groups; where m is at least 1; where n is at least
1; where o is 0 or greater; where p is 2 to 6; where q is 0 or
greater; wherein (m+n+o+q)=N.sub.NCO, where N.sub.NCO is the number
of isocyanate groups originally appended to R.sub.i; and wherein
the quantity (m+n+o)/N.sub.NCO is greater than or equal to 0.67,
and in which each unit referred to by the subscripts m, n, o, and q
is attached to an R.sub.i unit.
8. A fluorocarbon- and urethane-acrylate-containing additive
comprising one or more perfluoropolyether urethanes with
multi-meth(acryl) groups having the chemical formula:
(R.sub.i).sub.c--(NHC(O)XQR.sub.f).sub.m,
--(NHC(O)OQ(A).sub.p).sub.n,
--(NHC(O)XQG).sub.oR.sub.f(Q)(XC(O)NH).sub.y).sub.z--,
--NHC(O)XQD(QXC(O)NH).sub.u).sub.s--,
-D.sub.1(QXC(O)NH).sub.y).sub.zz--NHC(O)OQ(A).sub.tQ.sub.1Q(A).sub.tOC(O)-
NH)).sub.v--, --(NCO).sub.w; wherein R.sub.i is the residue of a
multi-isocyanate; where c is 1 to 50; where X is O, S or NR, where
R is H or lower alkyl; where R.sub.f is a monovalent
perfluoropolyether moiety composed of groups comprising the
formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--, each R.sub.fc
independently represents a fluorinated alkylene group having from 1
to 6 carbon atoms and each x independently represents an integer
greater than or equal to 2 and wherein d is an integer from 1 to 6;
where Q is independently a connecting group of valency at least 2
and is selected from the group consisting of a covalent bond, an
alkylene, an arylene, an aralkylene, an alkarylene, a straight or
branched chain or cycle-containing connecting group optionally
containing heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; wherein A is a (meth)acryl
functional group having the chemical formula:
(--XC(O)C(R.sub.2).dbd.CH.sub.2), where R.sub.2 is a lower alkyl of
1 to 4 carbon atoms or H or F; where G is selected from the group
consisting of an alkyl, an aryl, an alkaryl and an aralkyl, wherein
G optionally contains heteroatoms such as O, N, and S and
optionally has heteroatom-containing functional groups such as
carbonyl and sulfonyl and combinations of heteroatoms and
heteroatom-containing functional groups; and G optionally contains
pendant or terminal reactive groups selected from the group
consisting of (meth)acryl groups, vinyl groups, allyl groups and
--Si(OR.sub.3).sub.3 groups, where R.sub.3 is a lower alkyl of 1 to
4 carbon atoms; wherein G also optionally has fluoroalkyl or
perfluoroalkyl groups; wherein D is selected from the group
consisting of an alkylene, an arylene, an alkarylene, a
fluoroalkylene, a perfluoroalkylene and an aralkylene and
optionally contains heteroatoms such as O, N, and S; wherein
D.sub.1 is selected from the group consisting of an alkyl, an aryl,
an alkaryl, a fluoroalkyl, a perfluoroalkyl and an aralkyl group
and optionally contains heteroatoms such as O, N, and S; where
Q.sub.1 is independently a connecting group of valency at least 2
and is selected from the group consisting of a covalent bond, an
alkylene, an arylene, an aralkylene, an alkarylene, a straight or
branched chain or cycle-containing connecting group optionally
containing heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; where m or z is at least 1;
where n or v is at least 1; where o, s, v, and w are 0 or greater;
where (m+n+o+[(u+1)s]+2v+w)=cN.sub.NCO, where NNCO is the number of
isocyanate groups originally appended to R.sub.i; the quantity
(m+n+o+[(u+1)s]+2v)/(cN.sub.NCO) is greater than or equal to least
0.75, p is 2 to 6, t is 1 to 6, and u is independently 1 to 3, and
in which each unit referred to by the subscripts m, n, o, s, v and
w is attached to an R.sub.i unit.
9. A hardcoat composition comprising: a hardcoat-compatible,
monovalent perfluoropolyether moiety-containing urethane
multi-(meth)acryl additive; a hydrocarbon hardcoat composition; and
optionally a plurality of surface modified inorganic
nanoparticles.
10. The hardcoat composition of claim 9 comprising the additive of
claim 1.
11. The hardcoat composition of claim 9 comprising the additive of
claim 3.
12. The hardcoat composition of claim 9 comprising the additive of
claim 7.
13. The hardcoat composition of claim 9 comprising the additive of
claim 8.
14. The hard coating composition of claim 9, wherein said plurality
of surface modified inorganic nanoparticles comprises a plurality
of modified silica particles.
15. The hard coating composition of claim 9, wherein said
hydrocarbon-based hard coat formulation comprises an acrylate-based
hard coating formulation.
16. The hard coating composition of claim 9 further comprising a
particulate matting agent.
17. The hard coating composition of claim 9, wherein said additive
comprises between about 0.01% and 10% of the total solids of said
hard coating composition.
18. The hard coating composition of claim 9 further comprising a
compatabilizer selected from a) a free radically reactive
fluoroalkyl group-containing material having the chemical formula:
R.sub.ffQ.sub.3(X.sub.1).sub.n1; where R.sub.ff is a fluoroalkyl;
where Q.sub.3 is a connecting group of valency at least 2 and is
selected from the group consisting of a covalent bond, an alkylene,
an arylene, an aralkylene, an alkarylene group, a straight or
branched chain or cycle-containing connecting group optionally
containing heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; where X.sub.1 is a
free-radically reactive group selected from (meth)acryl, --SH,
allyl, or vinyl groups; and where n1 is independently 1 to 3; b) a
free radically reactive fluoroalkylene group having the chemical
formula: (X.sub.1).sub.n1Q.sub.3R.sub.ff2Q.sub.3(X.sub.1).sub.n1);
where R.sub.ff2 is a fluoroalkylene; where Q.sub.3 is a connecting
group of valency at least 2 and is selected from the group
consisting of a covalent bond, an alkylene, an arylene, an
aralkylene, an alkarylene group, a straight or branched chain or
cycle-containing connecting group optionally containing heteroatoms
such as O, N, and S and optionally a heteroatom-containing
functional group such as carbonyl or sulfonyl, and combinations
thereof; where X.sub.1 is a free-radically reactive group selected
from (meth)acryl, --SH, allyl, or vinyl groups; and where n1 is
independently 1 to 3; c) a fluoroalkyl- or
fluoroalkylene-substituted thiol or polythiol selected from the
group consisting of
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OC(O)CH.sub.2SH,
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OC(O)CH.sub.2CH.sub.2SH,
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2SH, and
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH(OC(O)CH.sub.2SH)CH.sub.2OC(O)CH.sub.2-
SH; and combinations of a), b) or c).
19. An optical display comprising: an optical substrate; and a
cured hardcoat composition disposed on the substrate wherein the
hardcoat comprising the composition of claim 9.
20. An optical display comprising: an optical substrate; a first
hardcoat layer disposed on the substrate; and a second hardcoat
surface layer disposed on the first hardcoat layer wherein the
second hardcoat surface layer comprises the composition of claim
9.
21. A fluorocarbon- and urethane-acrylate-containing additive
comprising one or more perfluoropolyether urethanes with
multi-meth(acryl) groups having the chemical formula:
(R.sub.i).sub.c--(NHC(O)XQR.sub.f).sub.m,
--(NHC(O)OQ(A).sub.p).sub.n, --(NHC(O)XQG).sub.o,
--(NHC(O)XQ-R.sub.f2(QXC(O)NH).sub.u).sub.r--,
--NHC(O)XQ-D(QXC(O)NH).sub.u).sub.s--,
-D.sub.1(QXC(O)NH).sub.y).sub.zz,
--NHC(O)OQ(A).sub.tQ.sub.1Q(A).sub.tOC(O)NH)).sub.v--,
--(NCO).sub.w; wherein R.sub.i is the residue of a
multi-isocyanate; where c is 1 to 50; where X is O, S or NR, where
R is H or lower alkyl; where R.sub.f is a monovalent
perfluoropolyether moiety composed of groups comprising the
formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--, each R.sub.fc
independently represents a fluorinated alkylene group having from 1
to 6 carbon atoms and each x independently represents an integer
greater than or equal to 2 and wherein d is an integer from 1 to 6;
where Q is independently a connecting group of valency at least 2
and is selected from the group consisting of a covalent bond, an
alkylene, an arylene, an aralkylene, an alkarylene, a straight or
branched chain or cycle-containing connecting group optionally
containing heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; wherein A is a (meth)acryl
functional group having the chemical formula:
(--XC(O)C(R.sub.2).dbd.CH.sub.2), where R.sub.2 is a lower alkyl of
1 to 4 carbon atoms or H or F; where G is selected from the group
consisting of an alkyl, an aryl, an alkaryl and an aralkyl, wherein
G optionally contains heteroatoms such as O, N, and S and
optionally has heteroatom-containing functional groups such as
carbonyl and sulfonyl and combinations of heteroatoms and
heteroatom-containing functional groups; and G optionally contains
pendant or terminal reactive groups selected from the group
consisting of (meth)acryl groups, vinyl groups, allyl groups and
--Si(OR.sub.3).sub.3 groups, where R.sub.3 is a lower alkyl of 1 to
4 carbon atoms; wherein G also optionally has fluoroalkyl or
perfluoroalkyl groups; where R.sub.f2 is a multi-valent
perfluoropolyether moiety, R.sub.f2 is composed of groups
comprising the formula:
Y((R.sub.fc1O).sub.xC.sub.d1F.sub.2d1).sub.b, wherein each
R.sub.fc1 is independently selected from: --CF(CF.sub.3)CF.sub.2--,
--CF.sub.2CF.sub.2CF.sub.2--, and
(CH.sub.2C(CH.sub.3)(CH.sub.2OCH.sub.2CF.sub.3)CH.sub.2--).sub.aa
where aa is 2 or greater; each x independently represents an
integer greater than or equal to 2, and d1 is an integer from 0 to
6; Y represents a polyvalent organic group or covalent bond having
a valence of b, and b represents an integer greater than or equal
to 2; wherein D is selected from the group consisting of an
alkylene, an arylene, an alkarylene, a fluoroalkylene, a
perfluoroalkylene and an aralkylene group and optionally contains
heteroatoms such as O, N, and S; wherein D.sub.1 is selected from
the group consisting of an alkyl, an aryl, an alkaryl, a
fluoroalkyl, a perfluoroalkyl and an aralkyl group and optionally
contains heteroatoms such as O, N, and S; where Q.sub.1 is
independently a connecting group of valency at least 2 and is
selected from the group consisting of a covalent bond, an alkylene,
an arylene, an aralkylene, an alkarylene, a straight or branched
chain or cycle-containing connecting group optionally containing
heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; where r is at least 1; where n
or v is at least 1; where m, o, s, v, and w are 0 or greater; where
(m+n+o+[(u+1)r]+[(u+1)s]+2v+w)=cN.sub.NCO, where NNCO is the number
of isocyanate groups originally appended to R.sub.i; the quantity
(m+n+o+[(u+1)r]+[(u+1)s]+2v)/(cN.sub.NCO) is greater than or equal
to least 0.75, p is 2 to 6, t is 1 to 6, and u is independently 1
to 3, and in which each unit referred to by the subscripts m, n, o,
r, s, v and w is attached to an R.sub.i unit.
22. A hard coating composition having the fluorocarbon- and
urethane-acrylate-containing additive of claim 21 and further
comprising a hydrocarbon-based hard coat formulation.
23. An optical display comprising: an optical substrate; a first
hardcoat layer disposed on the substrate; and a second hardcoat
surface layer disposed on the first hardcoat layer wherein the
second hardcoat surface layer comprises the composition of claim
22.
24. A method for forming an optical display comprising: (a) forming
an additive comprising a perfluoropolyether urethane having a
monovalent perfluoropolyether moiety and a multi-(meth)acryl
terminal group by first reacting a polyisocyanate with a hydroxyl
functional acrylate and further reacting the resultant compound
with a perfluoropolyether-containing alcohol or thiol having a
monovalent perfluoropolyether moiety, said additive having no free
isocyanate groups; (b) mixing said additive with a
hydrocarbon-based hardcoat composition to form a hard coating
composition; (c) applying said hard coating composition to an
optical substrate; and (d) curing said hard coating composition to
form a stain repellent optical hard coat on said optical
substrate.
25. A method for forming an optical display comprising: (a) forming
an additive comprising a perfluoropolyether urethane having a
monovalent perfluoropolyether moiety and a multi-(meth)acryl
terminal group by first reacting a polyisocyanate with a
perfluoropolyether-containing alcohol, thiol or amine having a
monovalent perfluoropolyether moiety and further reacting the
resultant compound with hydroxyl functional multiacrylate, said
additive having no free isocyanate groups; (b) mixing said additive
with a hydrocarbon-based hardcoat composition to form a hard
coating composition; (c) applying said hard coating composition to
an optical substrate; and (d) curing said hard coating composition
to form a stain repellent optical hard coat on said optical
substrate.
26. A hard coating composition for optical displays comprising: a
hydrocarbon-based hard coating composition; a compatibilizer
selected from the group consisting of a free radically reactive
fluoroalkyl group-containing compatibilizer, a free radically
reactive fluoroalkylene group-containing compatibilizer, and a
perfluoroalkyl substituted urethane mono or multi (meth)acrylate
compatibilizer; and a perfluoropolyether-substituted urethane
acrylate having the chemical formula:
R.sub.f-Q-(XC(O)NHQOC(O)C(R).dbd.CH.sub.2).sub.f: wherein R.sub.f
is a monovalent perfluoropolyether moiety composed of groups
comprising the formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--,
wherein each R.sub.fc independently represents a fluorinated
alkylene group having from 1 to 6 carbon atoms, each x
independently represents an integer greater than or equal to 2, and
wherein d is an integer from 1 to 6; wherein a is 2-15; wherein Q
is a connecting group of valency at least 2 and is selected from
the group consisting of a covalent bond, an alkylene, an arylene,
an aralkylene, an alkarylene group, a straight or branched chain or
cycle-containing connecting group optionally containing heteroatoms
such as O, N, and S and optionally a heteroatom-containing
functional group such as carbonyl or sulfonyl, and combinations
thereof; wherein X is O or S; and wherein f is 1-5.
Description
BACKGROUND OF THE INVENTION
[0001] Optical hard coats are applied to optical display surfaces
to protect them from scratching and marking. Desirable product
features in optical hard coats include durability to scratches and
abrasions, and resistance to inks and stains.
[0002] Materials that have been used to date for surface protection
include fluorinated polymers, or fluoropolymers. Fluoropolymers
provide advantages over conventional hydrocarbon based materials in
terms of high chemical inertness (in terms of solvent, acid, and
base resistance), dirt and stain resistance (due to low surface
energy), low moisture absorption, and resistance to weather and
solar conditions.
[0003] Fluoropolymers have also been investigated that are
crosslinked to a hydrocarbon-based hard coating formulation that
improves hardness and interfacial adhesion to a substrate. For
example, it is known that free-radically curable
perfluoropolyethers provide good repellency to inks from pens and
permanent markers when added to ceramer hard coat compositions,
which comprise a plurality of colloidal inorganic oxide particles
and a free-radically curable binder precursor, such as described in
U.S. Pat. No. 6,238,798 to Kang, and assigned to 3M Innovative
Properties Company of St. Paul, Minn.
[0004] Industry would find advantage in other fluoropolymer-based
hard coatings, particularly those having improved properties.
SUMMARY OF THE INVENTION
[0005] In one aspect, the invention relates to fluorocarbon- and
urethane-(meth)acryl-containing additives.
[0006] In one embodiment, the additive comprises a
perfluoropolyether urethane having a monovalent perfluoropolyether
moiety and a multi-(meth)acryl terminal group and is described in
the detailed description below as formula (1).
[0007] In another embodiment, the additive comprises a
perfluoropolyether-substituted urethane acrylate having a
monovalent perfluoropolyether moiety described in the detailed
description below as formula (3A) and more preferably as formula
(3B).
[0008] In a third embodiment, the additive comprises one or more
perfluoropolyether urethanes having a monovalent perfluoropolyether
moiety and a multi-(meth)acryl group of the formula (4) as
described further in the detailed description below.
[0009] In a fourth embodiment, the additive comprises one or more
perfluoropolyether urethanes having a monovalent perfluoropolyether
moiety and a multi-(meth)acryl group of the formula (5) as
described below in the detailed description.
[0010] In a fifth embodiment, the additive comprises one or more
perfluoropolyether urethanes with multi-(meth)acryl groups of the
formula (6) as described below in the detailed description.
[0011] In another aspect, the invention realtes to a hardcoat
composition comprising a (e.g. small amount of a)
hardcoat-compatible, monovalent perfluoropolyether
moiety-containing urethane multi-(meth)acryl additive, a
hydrocarbon hardocat composition; and optionally a plurality of
surface modified inorganic nanoparticles. The hardcoat preferably
comprises one or more of the embodied additives just described. The
hardcoat is preferably provided as a surface layer on an optical
substrate. The hardcoat may be provided as a single layer disposed
on an optical substrate. Alternatively, a first (e.g. different
composition) hardcoat layer may be disposed on the optical substate
with a hardcoat of the invention disposed on the first hardcoat
layer. Further, a particulate matting agent may be incorporate to
impart anti-glare properties to the optical hard coating layer. The
particulate matting agent can also prevent the reflectance decrease
and uneven coloration caused by interference of the hard coat layer
with the underlying substrate layer. In preferred embodiments, the
hardcoats provide any one or combination of enhanced stain and ink
repellency properties, adequate smoothness, and improved
durability.
[0012] The (e.g. optical) hard coats having these fluorocarbon
additives described herein generally do not need compatibilizers to
enhance the compatibility between a fluoropolymer additive and the
conventional hard coat material. Alternatively, however,
free-radically reactive fluoroalkyl or fluoroalkylene
group-containing compatibilizers can also be employed such as a
perfluorobutyl-substituted acrylate or a fluoroalkyl- or
fluoroalkylene-substituted thiol or polythiol.
[0013] Other objects and advantages of the present invention will
become apparent upon considering the following detailed description
and appended claims, and upon reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates an article having a hard coated optical
display formed in accordance with a preferred embodiment of the
present invention.
DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS
[0015] For the following defined terms, these definitions shall be
applied, unless a different definition is given in the claims or
elsewhere in the specification.
[0016] The term "(meth)acryl" refers to functional groups including
acrylates, methacrylates, acrylamides, methacrylamides,
alpha-fluoroacrylates, thioacrylates and thio-methacrylates. A
preferred (meth)acryl group is acrylate.
[0017] The term "monovalent perfluoropolyether moiety", refers to a
perfluoropolyether chain having one end terminated by a
perfluoroalkyl group.
[0018] The term "ceramer" is a composition having inorganic oxide
particles, e.g. silica, of nanometer dimensions dispersed in a
binder matrix. The phrase "ceramer composition" is meant to
indicate a ceramer formulation in accordance with the present
invention that has not been at least partially cured with radiation
energy, and thus is a flowing, coatable liquid. The phrase "ceramer
composite" or "coating layer" is meant to indicate a ceramer
formulation in accordance with the present invention that has been
at least partially cured with radiation energy, so that it is a
substantially non-flowing solid. Additionally, the phrase
"free-radically polymerizable" refers to the ability of monomers,
oligomers, polymers or the like to participate in crosslinking
reactions upon exposure to a suitable source of curing energy.
[0019] The term "polymer" will be understood to include polymers,
copolymers (e.g. polymers using two or more different monomers),
oligomers and combinations thereof, as well as polymers, oligomers,
or copolymers that can be formed in a miscible blend.
[0020] Unless otherwise noted, "HFPO--" refers to the end group
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)-- of the methyl ester
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)C(O)OCH.sub.3, wherein
"a" averages about 6.2, and the methyl ester has an average
molecular weight of 1,211 g/mol, and which can be prepared
according to the method reported in U.S. Pat. No. 3,250,808 (Moore
et al.), the disclosure of which is incorporated herein by
reference, with purification by fractional distillation.
[0021] The recitation of numerical ranges by endpoints includes all
numbers subsumed within the range (e.g. the range 1 to 10 includes
1, 1.5, 3.33, and 10).
[0022] As used in this specification and the appended claims, the
singular forms "a", "an", and "the" include plural referents unless
the content clearly indicates otherwise. Thus, for example,
reference to a composition containing "a compound" includes a
mixture of two or more compounds. As used in this specification and
the appended claims, the term "or" is generally employed in its
sense including "and/or" unless the content clearly dictates
otherwise.
[0023] Unless otherwise indicated, all numbers expressing
quantities of ingredients, measurements of properties such as
contact angle, and so like as used in the specification and claims
are to be understood to be modified in all instances by the term
"about."Accordingly, unless indicated to the contrary, the
numerical parameters set forth in the foregoing specification and
attached claims are approximations that can vary depending upon the
desired properties sought to be obtained by those skilled in the
art utilizing the teachings of the present invention. At the very
least, and not as an attempt to limit the application of the
doctrine of equivalents to the scope of the claims, each numerical
parameter should be at least be construed in light of the number of
reported significant digits and by applying ordinary rounding
techniques. Notwithstanding that the numerical ranges and
parameters set forth in the broad scope of the invention are
approximations, the numerical values set forth in the specific
examples are reported as accurately as possible. Any numerical
value, however, inherently contains certain errors necessarily
resulting from the standard deviations found in their respective
testing measurements.
[0024] The term "optical display", or "display panel", can refer to
any conventional optical displays, including but not limited to
multi-character multi-line displays such as liquid crystal displays
("LCDs"), plasma displays, front and rear projection displays,
cathode ray tubes ("CRTs"), and signage, as well as
single-character or binary displays such as light emitting diodes
("LEDs"), signal lamps and switches. The exposed surface of such
display panels may be referred to as a "lens." The invention is
particularly useful for displays having a viewing surface that is
susceptible to being touched or contacted by ink pens, markers and
other marking devices, wiping cloths, paper items and the like.
[0025] The protective coatings of the invention can be employed in
a variety of portable and non-portable information display
articles. These articles include PDAs, cell phones (including
combination PDA/cell phones), LCD televisions (direct lit and edge
lit), touch sensitive screens, wrist watches, car navigation
systems, global positioning systems, depth finders, calculators,
electronic books, CD and DVD players, projection television
screens, computer monitors, notebook computer displays, instrument
gauges, instrument panel covers, signage such as graphic displays
and the like. The viewing surfaces can have any conventional size
and shape and can be planar or non-planar, although flat panel
displays are preferred.
[0026] A combination of low surface energy (e.g. anti-soiling,
stain resistant, oil and/or water repellency) and durability (e.g.
abrasion resistance) is desired for the coating layer for these
displays while maintaining optical clarity. The hard coating layer
functions to decrease glare loss while improving durability and
optical clarity.
[0027] The surface energy can be characterized by various methods
such as contact angle and ink repellency, as determined by the test
methods described in the Examples. In this application, "stain
repellent" refers to a surface treatment exhibiting a static
contact angle with water of at least 70 degrees. More preferably,
the contact angle is at least 80 degrees and most preferably at
least 90 degrees. Alternatively, or in addition thereto, the
advancing contact angle with hexadecane is at least 50 degrees and
more preferably at least 60 degrees. Low surface energy results in
anti-soiling and stain repellent properties as well as rendering
the exposed surface easy to clean.
[0028] Another indicator of low surface energy relates to the
extent to which ink from a pen or marker beads up when applied to
the exposed surface. The surface layer and articles exhibit "ink
repellency" when ink from pens and markers can be easily removed by
wiping the exposed surface with tissues or paper towels, such as
tissues available from the Kimberly Clark Corporation, Roswell, Ga.
under the trade designation "SURPASS FACIAL TISSUE." Durability can
be defined in terms of results from a modified oscillating sand
test (Method ASTM F 735-94) carried out at 300 rpm for 15 minutes
as described in Experiment 1 of this application. Preferably, a
durable coating exhibits an ink repellency value of 65 mm or less,
more preferably 40 mm or less, most preferably 0 mm in this
test.
[0029] Coatings appropriate for use as optical hard coatings must
be substantially free of visual defects. Visual defects that may be
observed include but are not limited to pock marks, fish eyes,
mottle, lumps or substantial waviness, or other visual indicators
known to one of ordinary skill in the art in the optics and coating
fields. Thus, a "rough" surface as described in the Experimental
has one or more of these characteristics, and may be indicative of
a coating material in which one or more components of the
composition are incompatible with each other. Conversely, a
substantially smooth coating, characterized below as "smooth" for
the purpose of the present invention, presumes to have a coating
composition in which the various components, in the reacted final
state, form a coating in which the components are compatible or
have been modified to be compatible with one another and further
has little, if any, of the characteristics of a "rough"
surface.
[0030] Additionally, the surface layer preferably exhibits an
initial haze of less than 2% and/or an initial transmission of at
least 90%.
[0031] Referring now to FIG. 1, a perspective view of an article
(here a computer monitor 10) is illustrated as having an optical
display 12 coupled within a housing 14. The optical display 12 is a
substantially transparent material having optically enhancing
properties through which a user can view text, graphics or other
displayed information. The optical display 12 includes hard coating
layer 18 applied to an optical substrate 16. The thickness of the
hardcoat layer is typically at least 0.5 microns, preferably at
least 1 micron, and more preferably at least 2 microns. The
thickness of the hardcoat layer is generally no greater than 25
microns. Preferably the thickness ranges from 3 microns to 5
microns.
[0032] In another embodiment (not shown), the hardcoat layer
described herein (i.e. comprising at least one fluorocarbon- and
urethane-(meth)acryl-containing additive and at least one
non-fluorinated crosslinking agent) may be provided as a surface
layer having an additional hard coat layer underlying the hardcoat
surface layer. In this embodiment, the surface layer preferably
preferably has a thickness ranging from about 10 to 200
nanometers.
[0033] Various permanent and removable grade adhesive compositions
may be coated on the opposite side of the substrate 16 (i.e. to
that of the hardcoat 16) so the article can be easily mounted to a
display surface. Suitable adhesive compositions include (e.g.
hydrogenated) block copolymers such as those commercially available
from Kraton Polymers of Westhollow, Tex. under the trade
designation "Kraton G-1657", as well as other (e.g. similar)
thermoplastic rubbers. Other exemplary adhesives include
acrylic-based, urethane-based, silicone-based and epoxy-based
adhesives. Preferred adhesives are of sufficient optical quality
and light stability such that the adhesive does not yellow with
time or upon weather exposure so as to degrade the viewing quality
of the optical display. The adhesive can be applied using a variety
of known coating techniques such as transfer coating, knife
coating, spin coating, die coating and the like. Exemplary
adhesives are described in U.S. Patent Application Publication No.
2003/0012936. Several of such adhesives are commercially available
from 3M Company, St. Paul, Minn. under the trade designations 8141,
8142, and 8161.
[0034] The substrate layer 16 may consist of any of a wide variety
of non-polymeric materials, such as glass, or polymeric materials,
such as polyethylene terephthalate (PET), bisphenol A
polycarbonate, cellulose triacetate, poly(methyl methacrylate), and
biaxially oriented polypropylene which are commonly used in various
optical devices.
[0035] The composition of the hard coating layer 18, prior to
application and curing to the optical substrate 16, is formed from
a mixture of a conventional hydrocarbon-based, and more preferably
acrylate-based, hard coat composition and a fluorocarbon- and
urethane-acrylate-containing additive described in formulas (1),
(3A), (4), (5) and (6) below. Methods for forming the hard coating
compositions for each of the preferred embodiments are described
below in the experimental section.
[0036] In one preferred embodiment of the present invention, the
fluorocarbon- and urethane-acrylate-containing additive is a
perfluoropolyether urethane having a monovalent perfluoropolyether
moiety and a multi-acrylate terminal group combined with a
conventional hydrocarbon-based (more preferably acrylate-based)
hard coat material. The perfluoropolyether urethane having a
monovalent perfluoropolyether moiety and a multi-acrylate terminal
group is added at between about 0.01% and 10%, and more preferably
between about 0.1% and 1%, of the total solids of the hard coat
composition. The additive is ofthe formula (1):
R.sub.i--(NHC(O)XQR.sub.f).sub.m, --(NHC(O)OQ(A).sub.p).sub.n (1)
wherein R.sub.i is the residue of a multi-isocyanate; X is O, S or
NR, where R is H or lower alkyl of 1 to 4 carbon atoms; R.sub.f is
a monovalent perfluoropolyether moiety composed of groups
comprising the formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--,
wherein each R.sub.fc independently represents a fluorinated
alkylene group having from 1 to 6 carbon atoms, each x
independently represents an integer greater than or equal to 2, and
wherein d is an integer from 1 to 6; Q is independently a
connecting group of valency at least 2 and is selected from the
group consisting of a covalent bond, an alkylene, an arylene, an
aralkylene, an alkarylene, a straight or branched chain or
cycle-containing connecting group optionally containing heteroatoms
such as O, N, and S and optionally a heteroatom-containing
functional group such as carbonyl or sulfonyl, and combinations
thereof; A is a (meth)acryl functional group
--XC(O)C(R.sub.2).dbd.CH.sub.2, where R.sub.2 is a lower alkyl of 1
to 4 carbon atoms or H or F; m is at least 1;n is at least 1; p is
2 to 6, m+n is 2 to 10, and in which each unit referred to by the
subscripts m and n is attached to an R.sub.i unit.
[0037] By their method of synthesis, these materials are
necessarily mixtures. If the mole fraction of isocyanate groups is
arbitrarily given a value of 1.0, then the total mole fraction of m
and n units used in making materials of formula (1) is 1.0 or
greater. The mole fractions of m:n ranges from 0.95:0.05 to
0.05:0.95. Preferably, the mole fractions of m:n are from 0.50:0.50
to 0.05:0.95. More preferably, the mole fractions of m:n are from
0.25:0.75 to 0.05:0.95 and most preferably, the mole fractions of
m:n are from 0.25:0.75 to 0.10:0.95. In the instances the mole
fractions of m:n total more than one, such as 0.15:0.90, the m unit
is reacted onto the isocyanate first, and a slight excess (0.05
mole fraction) of the n units are used.
[0038] In a formulation, for instance, in which 0.15 mole fractions
of m and 0.85 mole fraction of n units are introduced, a
distribution of products is formed in which some fraction of
products formed contain no m units. There will, however, be present
in this product distribution, materials of formula (1).
[0039] Numerous diisocyanates (di-functional isocyanates), modified
diisocyanate materials, and higher functional isocyanates may be
used as R.sub.i in the present invention as the residue of
multi-isocyanate and still fall within the spirit of the present
invention. Most preferably, multifunctional materials based on
hexamethylene diisocyanate ("HDI") are utilized. One commercially
available derivative of HDI is Desmodur.TM. N100, available from
Bayer Polymers LLC of Pittsburgh, Pa.
[0040] Further, other diisocyanates such as toluene diisocyanate
("TDI") or isophorone diisocyanate ("IPDI") may also be utilized as
R.sub.i in the present invention. Non-limiting examples of
aliphatic and aromatic isocyanate materials, for example, that may
be used include Desmodur.TM. 3300, Desmodur.TM. TPLS2294, and
Desmodur.TM. N 3600, all obtained from Bayer Polymers LLC of
Pittsburgh, Pa.
[0041] Materials used to make the additive of formula (1) may be
described by the formula: HOQ(A).sub.p, which are exemplified by,
for instance, 1,3-glycerol dimethacrylate, available from Echo
Resins Inc. of Versailles, Mo.; and pentaerythritol triacrylate,
available as SR444C from Sartomer of Exton, Pa.
[0042] Preferably, the monovalent perfluoropolyether moiety R.sub.f
is a hexafluoropropylene oxide ("HFPO") moiety of the formula:
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)--, wherein a is between
about 3 and 10. Such species generally exist as a distribution or
mixture of oligomers with a range of values for a, so that the
average value of a may be non-integer.
[0043] Typically, the additives of this preferred embodiment are
made by first reacting the polyisocyanate with the
perfluoropolyether-containing alcohol, thiol, or amine, followed by
reaction with the hydroxyl functional multiacrylate, usually in a
non-hydroxylic solvent and in the presence of a catalyst such as an
organotin compound. Alternately, the additives of this preferred
embodiment are made by reacting the polyisocyanate with the
hydroxyl functional multiacrylate, followed by reaction with the
perfluoropolyether-containing alcohol, thiol, or amine, usually in
a non-hydroxylic solvent and in the presence of a catalyst such as
an organotin compound. In addition, the additives could be made by
reacting all three components simultaneously, usually in a
non-hydroxylic solvent and in the presence of a catalyst such as an
organotin compound.
[0044] One representative structure (2) of perfluoropolyether
urethanes with multi-acrylates terminal groups of formula (1) is
shown below as: ##STR1## which is the reaction product of the
biuret of HDI with one equivalent of HFPO oligomer amidol
(F(CF(CF.sub.3)CF.sub.2O).sub.6.5CF(CF.sub.3)C(O)NHCH.sub.2CH.sub.2OH),
and further with two equivalents of pentaerythritol
triacrylate.
[0045] In a slight alternative preferred variation of formula (1),
a hard coating composition may be formed by the addition of a
perfluoropolyether urethane with a mono-acrylate terminal group
according to the formula R.sub.i--(NHC(O)XQR.sub.f).sub.m,
--(NHC(O)OQA).sub.n to a hydrocarbon-based hard coating
formulation.
[0046] In another preferred embodiment of the present invention,
the fluorocarbon- and urethane-acrylate-containing additive
comprises a perfluoropolyether-substituted urethane acrylate having
a monovalent perfluoropolyether moiety added at between about 0.01%
and 10%, and more preferably between about 0.1% and 1%, of the
total solids of the hard coat composition. The additive is of the
formula (3A): R.sub.f-Q-(XC(O)NHQOC(O)C(R).dbd.CH.sub.2).sub.f (3A)
where R.sub.f is a monovalent perfluoropolyether moiety composed of
groups comprising the formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--,
wherein each R.sub.fc independently represents a fluorinated
alkylene group having from 1 to 6 carbon atoms, each x
independently represents an integer greater than or equal to 2, and
wherein d is an integer from 1 to 6; a is 2-15; Q is independently
a connecting group of valency at least 2 and is selected from the
group consisting of a covalent bond, an alkylene, an arylene, an
aralkylene, an alkarylene, a straight or branched chain or
cycle-containing connecting group optionally containing heteroatoms
such as O, N, and S and optionally a heteroatom-containing
functional group such as carbonyl or sulfonyl, and combinations
thereof; X is independently O, S or NR, where R is H or lower alkyl
of 1 to 4 carbon atoms and f is 1-5.
[0047] One preferred perfluoropolyether-substituted
urethane(meth)acrylate that meets the description of formula (3A)
is described more specifically in formula (3B):
HFPO-Q-(XC(O)NHQOC(O)C(R).dbd.CH.sub.2).sub.f (3B) where HFPO is
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)--; a is 2-15; Q is
independently a connecting group of valency at least 2 and is
selected from the group consisting of a covalent bond, an alkylene,
an arylene, an aralkylene, an alkarylene, a straight or branched
chain or cycle-containing connecting group optionally containing
heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; X is independently O, S or NR,
where R is H or lower alkyl of 1 to 4 carbon atoms and f is 1-5.
Two preferred HFPO-substituted urethane acrylates that can be
utilized include:
HFPO--C(O)NHC.sub.2H.sub.4OC(O)NHC.sub.2H.sub.4OC(O)C(CH.sub.3).dbd.CH.su-
b.2 and
HFPO--C(O)NHC(C.sub.2H.sub.5)(CH.sub.2OC(O)NHC.sub.2H.sub.4OC(O)C(-
CH.sub.3).dbd.CH.sub.2).sub.2.
[0048] In another preferred embodiment of the present invention,
the fluorocarbon- and urethane-acrylate-containing additive is
formed from one or more perfluoropolyether urethanes having a
monovalent perfluoropolyether moiety and multi-meth(acryl) groups
added at between about 0.01% and 10%, and more preferably between
about 0.1% and 1%, of the total solids of the hard coat
composition. The additive is of the formula (4):
R.sub.i--(NHC(O)XQR.sub.f).sub.m, --(NHC(O)OQ(A).sub.p).sub.n,
--(NHC(O)XQG).sub.o,--(NCO).sub.q (4) wherein R.sub.i is the
residue of a multi-isocyanate; X is independently O, S or NR, where
R is H or lower alkyl of 1 to 4 carbon atoms; R.sub.f is a
monovalent perfluoropolyether moiety composed of groups comprising
the formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--, wherein each
R.sub.fc independently represents a fluorinated alkylene group
having from 1 to 6 carbon atoms, each x independently represents an
integer greater than or equal to 2, and wherein d is an integer
from 1 to 6; Q is independently a connecting group of valency at
least 2 and is selected from the group consisting of a covalent
bond, an alkylene, an arylene, an aralkylene, an alkarylene, a
straight or branched chain or cycle-containing connecting group
optionally containing heteroatoms such as O, N, and S and
optionally a heteroatom-containing functional group such as
carbonyl or sulfonyl, and combinations thereof; A is a (meth)acryl
functional group --XC(O)C(R.sub.2).dbd.CH.sub.2, where R.sub.2 is a
lower alkyl of 1 to 4 carbon atoms or H or F; G is selected from
the group consisting of an alkyl, an aryl, an alkaryl and an
aralkyl, wherein G optionally contains heteroatoms such as O, N,
and S and optionally has heteroatom-containing functional groups
such as carbonyl and sulfonyl and combinations of heteroatoms and
heteroatom-containing functional groups; and G optionally contains
pendant or terminal reactive groups selected from the group
consisting of (meth)acryl groups, vinyl groups, allyl groups and
--Si(OR.sub.3).sub.3 groups, where R.sub.3 is a lower alkyl of 1 to
4 carbon atoms; wherein G also optionally has fluoroalkyl or
perfluoroalkyl groups; m is at least 1; n is at least 1; o is 0 or
greater; p is 2 to 6; q is 0 or greater; (m+n+o+q)=N.sub.NCO, where
N.sub.NCO is the number of isocyanate groups originally appended to
R.sub.i; and the quantity (m+n+o)/N.sub.NCO is greater than or
equal to 0.67, and in which each unit referred to by the subscripts
m, n, o, and q is attached to an R.sub.i unit. Preferably R.sub.fc
is --CF(CF.sub.3)CF.sub.2--.
[0049] The monoalcohol, monothiol or monoamine HXQG used in making
materials of formula (4) may include materials such as
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OH,
H.sub.2NCH.sub.2CH.sub.2CH.sub.2(SiOCH.sub.3).sub.3,
HSCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3, and HEA
("hydroxyethylacrylate").
[0050] In still another preferred embodiment of the present
invention, the fluorocarbon- and urethane-acrylate-containing
additive is formed from one or more perfluoropolyether urethanes
having a monovalent perfluoropolyether moiety and multi-meth(acryl)
groups added at between about 0.01% and 10%, and more preferably
between about 0.1% and 1%, of the total solids of the hard coat
composition. The additive is of the formula (5):
(R.sub.i).sub.c--(NHC(O)XQR.sub.f).sub.m,
--(NHC(O)OQ(A).sub.p).sub.n, --(NHC(O)XQG).sub.o,
(R.sub.f(Q)(XC(O)NH).sub.y).sub.z--,
--NHC(O)XQD(QXC(O)NH).sub.u).sub.s--,
D.sub.1(QXC(O)NH).sub.y).sub.zz--NHC(O)OQ(A).sub.tQ.sub.1Q(A).sub.tOC(O)N-
H)).sub.v--, --(NCO).sub.w (5) wherein R.sub.i is the residue of a
multi-isocyanate; c is 1 to 50; X is independently O, S or NR,
where R is H or lower alkyl; R.sub.f is a monovalent
perfluoropolyether moiety composed of groups comprising the
formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--, each R.sub.fc
independently represents a fluorinated alkylene group having from 1
to 6 carbon atoms and each x independently represents an integer
greater than or equal to 2 and wherein d is an integer from 1 to 6;
Q is independently a connecting group of valency at least 2 and is
selected from the group consisting of a covalent bond, an alkylene,
an arylene, an aralkylene, an alkarylene, a straight or branched
chain or cycle-containing connecting group optionally containing
heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; A is a (meth)acryl functional
group having the chemical formula:
(--XC(O)C(R.sub.2).dbd.CH.sub.2), where R.sub.2 is a lower alkyl of
1 to 4 carbon atoms or H or F; G is selected from the group
consisting of an alkyl, an aryl, an alkaryl and an aralkyl, wherein
G optionally contains heteroatoms such as O, N, and S and
optionally has heteroatom-containing functional groups such as
carbonyl and sulfonyl and combinations of heteroatoms and
heteroatom-containing functional groups; and wherein G optionally
contains pendant or terminal reactive groups selected from the
group consisting of (meth)acryl groups, vinyl groups, allyl groups
and --Si(OR.sub.3).sub.3 groups, where R.sub.3 is a lower alkyl of
1 to 4 carbon atoms; wherein G also optionally has fluoroalkyl or
perfluoroalkyl groups; D is selected from the group consisting of
an alkylene, an arylene, an alkarylene, a fluoroalkylene, a
perfluoroalkylene and an aralkylene and optionally contains
heteroatoms such as O, N, and S; D.sub.1 is selected from the group
consisting of an alkyl, an aryl, an alkaryl, a fluoroalkyl, a
perfluoroalkyl and an aralkyl group and optionally contains
heteroatoms such as O, N, and S; Q.sub.1 is a connecting group
defined in the same way as Q; m or z is at least 1; n or v is at
least 1; y is independently 2 or greater; o, s, v, w, z and zz are
0 or greater; (m+n+o+[(u+1)s]+2v+w+yz+y(zz))=cN.sub.NCO, where
N.sub.NCO is the number of isocyanate groups originally appended to
R.sub.i; the quantity (m+n+o+([(u+1)s]+2v+yz+y(zz))/(cN.sub.NCO) is
greater than or equal to least 0.75; p is 2 to 6; t is 1 to 6; and
u is independently 1 to 3; in which each unit referred to by the
subscripts m, n, o, s, v, w, z and zz is attached to an R.sub.i
unit; and preferably R.sub.fc is --CF(CF.sub.3)CF.sub.2--.
[0051] In this embodiment, when added to the conventional
hydrocarbon-based hard coating material, care must be taken in
choosing the ratios and amounts of reactive components to avoid
highly crosslinked urethane polymer gels. For instance, if a
trifunctional isocyanate is to be used with a multifunctional
alcohol, the amount of multifunctional alcohol should be limited to
avoid forming a crosslinked network. For higher numbers of c for
(R.sub.i).sub.c groups, it is preferred that diols and
diisocyanates be primarily used.
[0052] The materials used to make the additive of formula (5)
include those of the formula: R.sub.f(Q)(XH).sub.y, which is
exemplified by
HFPO--C(O)NHCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2OH).sub.2.
[0053] The materials used to make the additive of formula (5)
include those of the formula: HXQDQXH, which is exemplified by
hydrocarbon polyols such as HO(CH.sub.2).sub.10OH and
fluorochemical diols such as
HOCH.sub.2(CF.sub.2).sub.4CH.sub.2OH.
[0054] The materials used to make the additive of formula (5) may
include those of the formula: D(QXH).sub.y).sub.zz, which is
exemplified by fluorochemical diols
C.sub.4F.sub.9SO.sub.2N(CH.sub.2CH.sub.2OH).sub.2.
[0055] The materials used to make the additive of formula (5) may
also include those of the formula: HOQ(A).sub.tQ.sub.1Q(A).sub.tOH,
which is exemplified by Hydantoin hexaacrylate (HHA), prepared as
described in Example 1 of U.S. patent application No. 4,262,072 to
Wendling et al, and
CH.sub.2.dbd.C(CH.sub.3)C(O)OCH.sub.2CH(OH)CH.sub.2O(CH.sub.2).sub.4OCH.s-
ub.2CH(OH)CH.sub.2OC(O)C(CH.sub.3).dbd.CH.sub.2.
[0056] In still another preferred embodiment of the present
invention, the fluorocarbon- and urethane-acrylate-containing
additive is formed from one or more perfluoropolyether urethanes
with multi-meth(acryl) groups added at between about 0.01% and 10%,
and more preferably between about 0.1% and 1%, of the total solids
of the hard coat composition. The additive is of the formula (6):
(R.sub.i).sub.c--(NHC(O)XQR.sub.f).sub.m,
--(NHC(O)OQ(A).sub.p).sub.n, --(NHC(O)XQG),
--(NHC(O)XQR.sub.f2(QXC(O)NH).sub.u).sub.r--,
--NHC(O)XQD(QXC(O)NH).sub.u).sub.s--,
D.sub.1(QXC(O)NH).sub.y).sub.zz--NHC(O)OQ(A).sub.tQ.sub.1Q(A).sub.tOC(O)N-
H)).sub.v--, --(NCO).sub.w (6) wherein R.sub.i is the residue of a
multi-isocyanate; c is 1 to 50; X is independently O, S or NR,
where R is H or lower alkyl; R.sub.f is a monovalent
perfluoropolyether moiety composed of groups comprising the
formula: F(R.sub.fcO).sub.xC.sub.dF.sub.2d--, each R.sub.fc
independently represents a fluorinated alkylene group having from 1
to 6 carbon atoms and each x independently represents an integer
greater than or equal to 2 and wherein d is an integer from 1 to 6;
Q is independently a connecting group of valency at least 2 and is
selected from the group consisting of a covalent bond, an alkylene,
an arylene, an aralkylene, an alkarylene, a straight or branched
chain or cycle-containing connecting group optionally containing
heteroatoms such as O, N, and S and optionally a
heteroatom-containing functional group such as carbonyl or
sulfonyl, and combinations thereof; A is a (meth)acryl functional
group having the chemical formula:
(--XC(O)C(R.sub.2).dbd.CH.sub.2), where R.sub.2 is a lower alkyl of
1 to 4 carbon atoms or H or F; G is selected from the group
consisting of an alkyl, an aryl, an alkaryl and an aralkyl, wherein
G optionally contains heteroatoms such as O, N, and S and
optionally has heteroatom-containing functional groups such as
carbonyl and sulfonyl and combinations of heteroatoms and
heteroatom-containing functional groups; and wherein G optionally
contains pendant or terminal reactive groups selected from the
group consisting of (meth)acryl groups, vinyl groups, allyl groups
and --Si(OR.sub.3).sub.3 groups, where R.sub.3 is a lower alkyl of
1 to 4 carbon atoms; G also optionally has fluoroalkyl or
perfluoroalkyl groups; R.sub.f2 is a multi-valent fluoropolyether
moiety, R.sub.f2 is composed of groups comprising the formula:
Y((R.sub.fc1O).sub.xC.sub.d1F.sub.2d1).sub.b, wherein each
R.sub.fc1 independently represents a fluorinated alkylene group
having from 1 to 6 carbon atoms: each x independently represents an
integer greater than or equal to 2, and d1 is an integer from 0 to
6; Y represents a polyvalent organic group or covalent bond having
a valence of b, and b represents an integer greater than or equal
to 2; D is selected from the group consisting of an alkylene, an
arylene, an alkarylene, a fluoroalkylene, a perfluoroalkylene and
an aralkylene group and optionally contains heteroatoms such as O,
N, and S; D.sub.1 is selected from the group consisting of an
alkyl, an aryl, an alkaryl, a fluoroalkyl, a perfluoroalkyl and an
aralkyl group and optionally contains heteroatoms such as O, N, and
S; Q.sub.1 is a connecting group defined in the same way as Q; r is
at least 1; n or v is at least 1; y is independently 2 or greater;
m, o, s, v, w and zz are 0 or greater;
(m+n+o+[(u+1)r]+[(u+1)s]+2v+w+y(zz))=cN.sub.NCO, where N.sub.NCO is
the number of isocyanate groups originally appended to R.sub.i; the
quantity (m+n+o+[(u+1)r]+[(u+1)s]+2v+y(zz))/(cN.sub.NCO) is greater
than or equal to least 0.75; p is 2 to 6; t is 1 to 6; u is
independently 1 to 3; in which each unit referred to by the
subscripts m, n, o, r, s, v, w, and zz is attached to an R.sub.i
unit; and R.sub.fc1 is preferably independently selected from:
--CF(CF.sub.3)CF.sub.2--, --CF.sub.2CF.sub.2CF.sub.2--, and
(--CH.sub.2C(R)(CH.sub.2OCH.sub.2C.sub.dF.sub.2d+1)CH.sub.2--).sub.aa
where aa is 2 or greater and d and R are defined above.
[0057] The materials used to make the additive of formula (9) may
also include those of the formula: HXQR.sub.f2QXH, which is
exemplified by
(H(OCH.sub.2C(CH.sub.3)(CH.sub.2OCH.sub.2CF.sub.3)CH.sub.2).sub.aaOH)
(Fox-Diol, having a MW about 1342 and available from Omnova
Solutions Inc. of Akron, Ohio).
[0058] In preferred embodiments the fluorocarbon- and
urethane-(meth)acryl additive(s) described herein are employed as
the sole perfluoropolyether containing additive in a hardcoat
composition. Alternatively, however, the additive(s) described
herein may be employed in combination with various other
perfluoropolyether fluorocarbon(meth)acryl materials such as
HFPO--C(O)NHCH.sub.2CH.sub.2OC(O)CH.dbd.CH.sub.2 and various
(per)fluoropolyether acryl compounds such as described in U.S.
application Ser. No. 10/841159, filed May 7, 2004; (Docket No.
59727US002) and U.S. Provisional Application Ser. No. 60/569351,
filed May 7, 2004 (Docket No. 59795US002); incorporated by
reference. Exemplary materials include compound of the structures:
HFPO--C(O)N(H)C(CH.sub.2OC(O)CH.dbd.CH.sub.2).sub.2CH.sub.2CH.sub.3,
and HFPO--C(O)N(H)C(CH.sub.2OC(O)CH.dbd.CH.sub.2).sub.2H.
[0059] The hardcoat may be provided as a single layer disposed on
an optical substrate. In this construction, the total of all
(per)fluoropolyether acryl compounds, (i.e. the fluorocarbon- and
urethane-(meth)acryl additive(s) of the invention and other
perfluoropolyether fluorocarbon(meth)acryl materials) ranges from
0.01% to 10%, and more preferably from 0.1% to 1%, of the total
solids of the hard coat composition. For embodiments wherein a
first (e.g. different composition) hardcoat layer is disposed on
the optical substate with a hardcoat of the invention disposed on
the first hardcoat layer the fluorocarbon- and
urethane-(meth)acryl-containing additives described herein may be
present in the surface coating at amounts ranging from 0.01 to 50
wt-% solids, and more preferably from 1 to 25 wt-% solids; whereas
the various other (per)fluoropolyether acryl compounds may be
present at weight percents from 1 to 20%, and preferably from 1 to
10%. Preferably, the ratio of fluorocarbon- and
urethane-(meth)acry-containing additive to other
(per)fluoropolyether acryl compounds is at least 1 to 1 and more
preferably is about 3 to 1.
[0060] The fluorocarbon- and urethane(meth)acryl additives (e.g.
those of formulas (1), (3A), (4), (5) or (6)) optionally in
combination with various other (per)fluoropolyether(meth)acryl
compounds may be combined with one or more compatibilizers.
[0061] A class of free-radically reactive fluoroalkyl or
fluoroalkylene group-containing compatibilizers of the respective
chemical formulas: R.sub.ffQ.sub.3(X.sub.1).sub.n1 and
(X.sub.1).sub.n1Q.sub.3R.sub.ff2Q.sub.3(X.sub.1).sub.n1), where
R.sub.ff is a fluoroalkyl, R.sub.ff2 is a fluoroalkylene, Q.sub.3
is a connecting group of valency at least 2 and is selected from
the group consisting of a covalent bond, an alkylene, an arylene,
an aralkylene, an alkarylene group, a straight or branched chain or
cycle-containing connecting group optionally containing heteroatoms
such as O, N, and S and optionally a heteroatom-containing
functional group such as carbonyl or sulfonyl, and combinations
thereof; X.sub.1 is a free-radically reactive group selected from
(meth)acryl, --SH, allyl, or vinyl groups and n1 is independently 1
to 3. Typical Q.sub.3 groups include:
--SO.sub.2N(R)CH.sub.2CH.sub.2--;
--SO.sub.2N(CH.sub.2CH.sub.2).sub.2--; --(CH.sub.2).sub.m--;
--CH.sub.2O(CH.sub.2).sub.3--; and --C(O)NRCH.sub.2CH.sub.2--,
where R is H or lower alkyl of 1 to 4 carbon atoms and m is 1 to 6.
Preferably the fluoroalkyl or fluoroalkylene group is a
perfluoroalkyl or perfluoroalkylene group. One preferred class of
fluoroalkyl- or alkylene-substituted compatibilizers meeting these
criteria for use in the composition of the hard coat layer 18 is
the perfluorobutyl-substituted acrylate compatibilizers. Exemplary,
non-limiting perfluorobutyl-substituted acrylate compatibilizers
meeting these criteria and useful in the present invention include
one or more of
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OC(O)CH.dbd.CH.sub.2,
C.sub.4F.sub.9SO.sub.2N(CH.sub.2CH.sub.2OC(O)CH.dbd.CH.sub.2).sub.2,
or
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OC(O)C(CH.sub.3).dbd.CH.-
sub.2. The free-radically reactive fluoroalkyl or fluoroalkylene
group-containing compatibilizers described above are preferably
added at between about 0.5% and 20%, and more preferably between
about 1% and 10%, of the total solids of the hard coat
composition.
[0062] One non-limiting example of a preferred
fluoroalkyl-substituted compatibilizer that may be utilized in the
composition of the hard coat layer 18 is:
(1H,1H,2H,2H)-perfluorodecyl acrylate, available from Lancaster
Synthesis of Windham, N.H. Numerous other (meth)acryl compounds
with perfluoroalkyl moieties that may also be utilized in the
composition of the hard coat layer are mentioned in U.S. Pat. No.
4,968,116, to Hulme-Lowe et al., and in U.S. Pat. No. 5,239,026
(including perfluorocyclohexylmethyl methacrylate), to Babirad et
al., which are assigned to Minnesota Mining and Manufacturing
Company of St. Paul, Minn. and are herein incorporated by
reference. Other fluorochemical (meth)acrylates that meet these
criteria and may be utilized include, for example,
2,2,3,3,4,4,5,5-octafluorohexanediol diacrylate and .omega.-hydro
2,2,3,3,4,4,5,5-octafluoropentyl acrylate
(H--C.sub.4F.sub.8--CH.sub.2O--C(O)--CH.dbd.CH.sub.2). Other
fluorochemical (meth)acrylates that may be used alone, or as
mixtures, are described in U.S. Pat. No. 6,238,798, to Kang et al.,
and assigned to Minnesota Mining and Manufacturing Company of St.
Paul, Minn., and herein incorporated by reference.
[0063] Another compatibilizer that may be used is a fluoroalkyl- or
fluoroalkylene-substituted thiol or polythiol to a ceramer hard
coating composition. Non-limiting examples of this type of
compatibilizer includes one or more of the following:
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OC(O)CH.sub.2SH,
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OC(O)CH.sub.2CH.sub.2SH,
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2SH, and
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH(OC(O)CH.sub.2SH)CH.sub.2OC(O)CH.sub.2-
SH.
[0064] The conventional hard coat material used as a portion of
layer 18 in any of the preferred embodiments described above is a
hydrocarbon-based material well known to those of ordinary skill in
the optical arts. Most preferably, the hydrocarbon-based material
is an acrylate-based hard coat material. One preferable hard coat
material for use in the present invention is based on PETA
(pentaerythritol tri/tetra acrylate). One commercially available
form of pentaerythritol triacrylate ("PET3A") is SR444C and one
commercially available form of pentaerythritol tetraacrylate
("PET4A") is SR295, each available from Sartomer Company of Exton,
Pa.
[0065] However, other crosslinking agents may be used in the
present invention. Useful crosslinking agents include, for example,
poly(meth)acryl monomers selected from the group consisting of (a)
di(meth)acryl containing compounds such as 1,3-butylene glycol
diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate,
1,6-hexanediol monoacrylate monomethacrylate, ethylene glycol
diacrylate, alkoxylated aliphatic diacrylate, alkoxylated
cyclohexane dimethanol diacrylate, alkoxylated hexanediol
diacrylate, alkoxylated neopentyl glycol diacrylate, caprolactone
modified neopentylglycol hydroxypivalate diacrylate, caprolactone
modified neopentylglycol hydroxypivalate diacrylate,
cyclohexanedimethanol diacrylate, diethylene glycol diacrylate,
dipropylene glycol diacrylate, ethoxylated (10) bisphenol A
diacrylate, ethoxylated (3) bisphenol A diacrylate, ethoxylated
(30) bisphenol A diacrylate, ethoxylated (4) bisphenol A
diacrylate, hydroxypivalaldehyde modified trimethylolpropane
diacrylate, neopentyl glycol diacrylate, polyethylene glycol (200)
diacrylate, polyethylene glycol (400) diacrylate, polyethylene
glycol (600) diacrylate, propoxylated neopentyl glycol diacrylate,
tetraethylene glycol diacrylate, tricyclodecanedimethanol
diacrylate, triethylene glycol diacrylate, tripropylene glycol
diacrylate; (b) tri(meth)acryl containing compounds such as
glycerol triacrylate, trimethylolpropane triacrylate, ethoxylated
triacrylates (e.g., ethoxylated (3) trimethylolpropane triacrylate,
ethoxylated (6) trimethylolpropane triacrylate, ethoxylated (9)
trimethylolpropane triacrylate, ethoxylated (20) trimethylolpropane
triacrylate), propoxylated triacrylates (e.g., propoxylated (3)
glyceryl triacrylate, propoxylated (5.5) glyceryl triacrylate,
propoxylated (3) trimethylolpropane triacrylate, propoxylated (6)
trimethylolpropane triacrylate), trimethylolpropane triacrylate,
tris(2-hydroxyethyl)isocyanurate triacrylate; (c) higher
functionality (meth)acryl containing compounds such as
ditrimethylolpropane tetraacrylate, dipentaerythritol
pentaacrylate, ethoxylated (4) pentaerythritol tetraacrylate,
caprolactone modified dipentaerythritol hexaacrylate; (d)
oligomeric (meth)acryl compounds such as, for example, urethane
acrylates, polyester acrylates, epoxy acrylates; polyacrylamide
analogues of the foregoing; and combinations thereof. Such
compounds are widely available from vendors such as, for example,
Sartomer Company of Exton, Pa.; UCB Chemicals Corporation of
Smyrna, Ga.; and Aldrich Chemical Company of Milwaukee, Wis.
Additional useful (meth)acrylate materials include hydantoin
moiety-containing poly(meth)acrylates, for example, as described in
U.S. Pat. No. 4,262,072 (Wendling et al.).
[0066] To facilitate curing, polymerizable compositions according
to the present invention may further comprise at least one
free-radical thermal initiator and/or photoinitiator. Typically, if
such an initiator and/or photoinitiator are present, it comprises
less than about 10 percent by weight, more typically less than
about 5 percent of the polymerizable composition, based on the
total weight of the polymerizable composition. Free-radical curing
techniques are well known in the art and include, for example,
thermal curing methods as well as radiation curing methods such as
electron beam or ultraviolet radiation. Further details concerning
free radical thermal and photopolymerization techniques may be
found in, for example, U.S. Pat. No. 4,654,233 (Grant et al.); U.S.
Pat. No. 4,855,184 (Klun et al.); and U.S. Pat. No. 6,224,949
(Wright et al.).
[0067] Useful free-radical thermal initiators include, for example,
azo, peroxide, persulfate, and redox initiators, and combinations
thereof.
[0068] Useful free-radical photoinitiators include, for example,
those known as useful in the UV cure of acrylate polymers. Such
initiators include benzophenone and its derivatives; benzoin,
alpha-methylbenzoin, alpha-phenylbenzoin, alpha-allylbenzoin,
alpha-benzylbenzoin; benzoin ethers such as benzil dimethyl ketal
(commercially available under the trade designation "IRGACURE 651 "
from Ciba Specialty Chemicals Corporation of Tarrytown, N.Y.),
benzoin methyl ether, benzoin ethyl ether, benzoin n-butyl ether;
acetophenone and its derivatives such as
2-hydroxy-2-methyl-1-phenyl-1-propanone (commercially available
under the trade designation "DAROCUR 1173" from Ciba Specialty
Chemicals Corporation) and 1-hydroxycyclohexyl phenyl ketone
(commercially available under the trade designation "IRGACURE 184",
also from Ciba Specialty Chemicals Corporation);
2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone
commercially available under the trade designation "IRGACURE 907",
also from Ciba Specialty Chemicals Corporation);
2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone
commercially available under the trade designation "IRGACURE 369"
from Ciba Specialty Chemicals Corporation); aromatic ketones such
as benzophenone and its derivatives and anthraquinone and its
derivatives; onium salts such as diazonium salts, iodonium salts,
sulfonium salts; titanium complexes such as, for example, that
which is commercially available under the trade designation "CGI
784 DC", also from Ciba Specialty Chemicals Corporation);
halomethylnitrobenzenes; and mono- and bis-acylphosphines such as
those available from Ciba Specialty Chemicals Corporation under the
trade designations "IRGACURE 1700", "IRGACURE 1800", "IRGACURE
1850", "IRGACURE 819" "IRGACURE 2005", "IRGACURE 2010", "IRGACURE
2020" and "DAROCUR 4265". Combinations of two or more
photoinitiators may be used. Further, sensitizers such as
2-isopropyl thioxanthone, commercially available from First
Chemical Corporation, Pascagoula, Miss., may be used in conjunction
with photoinitiator(s) such as "IRGACURE 369".
[0069] The composition of any of these preferred embodiments is
applied to an optical substrate layer 16 of an optical display 12
and photocured to form the easy to clean, stain and ink repellent
optical hard coating layer 18. The presence of the urethane
functionality, in addition to the fluorocarbon component, in the
additive eliminates the need for comonomers introduced to the
composition to compatibilize the fluorochemical component with the
hydrocarbon-based crosslinker.
[0070] In still another preferred embodiment, the hard coat
material forming layer 18 of any of the above-preferred embodiments
further contains surface modified inorganic particles that add
mechanical strength to the resultant coating. One example of such
particles is colloidal silica reacted with a methacryl silane
coupling agent such as A-174 (available from Natrochem, Inc.),
other dispersant aids such as N,N dimethylacrylamide and various
other additives (stabilizers, initiators, etc.).
[0071] In still another preferred embodiment of any of the above
preferred embodiments described above, a particulate matting agent
is incorporated into the composition of the layer 18 in order to
impart anti-glare properties to the layer 18. The particulate
matting agent also prevents the reflectance decrease and uneven
coloration caused by interference with an associated hard coat
layer. The particulate matting agent should preferably be
transparent, exhibiting transmission values of greater than about
90%. Alternatively, or in addition thereto, the haze value is
preferably less than about 5%, and more preferably less than about
2%, and most preferably less than about 1%.
[0072] Exemplary systems incorporating matting agents into a hard
coating layer, but having a different hard coating composition, are
described, for example, in U.S. Pat. No. 6,693,746, and herein
incorporated by reference. Further, exemplary matte films are
commercially available from U.S.A. Kimoto Tech of Cedartown, Ga.,
under the trade designation "N4D2A."
[0073] The amount of particulate matting agent added is between
about 0.5 and 10% of the total solids of the composition, depending
upon the thickness of the layer 18, with a preferred amount around
2%. The anti-glare layer 18 preferably has a thickness of 0.5 to 10
microns, more preferably 0.8 to 7 microns, which is generally in
the same thickness range of gloss hard coatings.
[0074] The average particle diameter of the particulate matting
agent has a predefined minimum and maximum that is partially
dependent upon the thickness of the layer. However, generally
speaking, average particle diameters below 1.0 microns do not
provide the degree of anti-glare sufficient to warrant inclusion,
while average particle diameters exceeding 10.0 microns deteriorate
the sharpness of the transmission image. The average particle size
is thus preferably between about 1.0 and 10.0 microns, and more
preferably between 1.7 and 3.5 microns, in terms of the
number-averaged value measured by the Coulter method.
[0075] As the particulate matting agent, inorganic particles or
resin particles are used including, for example, amorphous silica
particles, TiO.sub.2 particles, Al.sub.2O.sub.3 particles,
cross-linked acrylic polymer particles such as those made of
cross-linked poly(methyl methacrylate), cross-linked polystyrene
particles, melamine resin particles, benzoguanamine resin
particles, and cross-linked polysiloxane particles. By taking into
account the dispersion stability and sedimentation stability of the
particles in the coating mixture for the anti-glare layer and/or
the hard coat layer during the manufacturing process, resin
particles are more preferred, and in particular cross-linked
polystyrene particles are preferably used since resin particles
have a high affinity for the binder material and a small specific
gravity.
[0076] As for the shape of the particulate matting agent, spherical
and amorphous particles can be used. However, to obtain a
consistent anti-glare property, spherical particles are desirable.
Two or more kinds of particulate materials may also be used in
combination.
[0077] Thin coating layers 18 of any of the preferred embodiments
can be applied to the optical substrate 16 using a variety of
techniques, including dip coating, forward and reverse roll
coating, wire wound rod coating, and die coating. Die coaters
include knife coaters, slot coaters, slide coaters, fluid bearing
coaters, slide curtain coaters, drop die curtain coaters, and
extrusion coaters among others. Many types of die coaters are
described in the literature such as by Edward Cohen and Edgar
Gutoff, Modem Coating and Drying Technology, VCH Publishers, NY
1992, ISBN 3-527-28246-7 and Gutoff and Cohen, Coating and Drying
Defects: Troubleshooting Operating Problems, Wiley Interscience, NY
ISBN 0-471-59810-0.
[0078] A die coater generally refers to an apparatus that utilizes
a first die block and a second die block to form a manifold cavity
and a die slot. The coating fluid, under pressure, flows through
the manifold cavity and out the coating slot to form a ribbon of
coating material. Coatings can be applied as a single layer or as
two or more superimposed layers. Although it is usually convenient
for the substrate to be in the form of a continuous web, the
substrate may also be a succession of discrete sheets.
[0079] To prove the effectiveness of the hard coat formulations
according to each preferred embodiment of the present invention
described above, sample hard coats having the given compositions
were formulated and applied to PET substrates and compared to hard
coat formulations having less than all the desired components. The
coatings were visually inspected and tested for ink repellency,
durability and surface roughness. The experimental procedures and
tabulated results are described below:
I. EXPERIMENTAL PROCEDURES
A: Ingredients
[0080] Unless otherwise noted, as used in the examples, "HFPO--"
refers to the end group
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)-- wherein a averages
about 6.22, with an average molecular weight of 1,211 g/mol, can be
prepared according to the method reported in U.S. Pat. No.
3,250,808 (Moore et al.), the disclosure of which is incorporated
herein by reference, with purification by fractional
distillation.
[0081] Polyisocyanates Desmodur.TM. (Des) N100, Desmodur.TM. 3300,
Desmodur.TM. TPLS2294, Desmodur.TM. N 3600, and Isophorone
diisocyanate (IPDI) were obtained from Bayer Polymers LLC, of
Pittsburgh, Pa.
[0082] PAPI (Poly[(phenyl isocyanate)-co-formaldehyde]) (MW about
375), is available from Sigma Aldrich of Milwaukee, Wis.
[0083] C.sub.6F.sub.13C.sub.2H.sub.4OH is available from Sigma
Aldrich of Milwaukee, Wis.
[0084] 4-methoxy phenol (MEHQ) is available from Sigma Aldrich of
Milwaukee, Wis.
[0085] HO(CH.sub.2).sub.10OH is available from Sigma Aldrich of
Milwaukee, Wis.
[0086] FOX-diol
(H(OCH.sub.2CCH.sub.3(CH.sub.2OCH.sub.2CF.sub.3)CH.sub.2).sub.xOH)
(MW about 1342), is available from Omnova Solutions Inc. of Akron,
Ohio.
[0087] Pentaerythritol tetracrylate ("PET4A"), under the trade
designation "SR295", was obtained from Sartomer Company of Exton,
Pa.
[0088] Pentaerythritol triacrylate ("PET3A"), under the trade
designation "SR444C", was obtained from Sartomer Company of Exton,
Pa.
[0089] Trimethylolpropane triacrylate ("TMPTA"), under the trade
designation "SR351", was obtained from Sartomer Company of Exton,
Pa.
[0090] Hydantoin hexaacrylate (HHA) was prepared as described in
Example 1 of U.S. Pat. No. 4,262,072.
[0091] FBSEE (C.sub.4F.sub.9SO.sub.2N(C.sub.2H.sub.4OH).sub.2), a
fluorochemical diol, can be prepared as described in column 5, line
31 and in FIG. 9 of U.S. Pat. No. 3,734,962 (1973).
[0092] MeFBSE (C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OH)
was prepared by essentially following the procedure described in
U.S. Pat. No. 6,664,354 (Savu et al.), Example 2, Part A.
[0093] FBSEA
(C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2OC(O)CH.dbd.CH.sub.2)
is made by the procedure of Examples 2A and 2B of WO 01/30873 to
Savu et al.
[0094] HFPO AEA (HFPO--C(O)NHCH.sub.2CH.sub.2OC(O)CH.dbd.CH.sub.2)
was prepared as described in File number U.S. application Ser. No.
10/841159, filed May 7, 2004 (Docket No. 57927US002); under
Preparation of Monofunctional Perfluoropolyether Acrylate
(FC-1).
[0095] Fomblin Zdol
(HOCH.sub.2CF.sub.2(OCF.sub.2CF.sub.2).sub.n(OCF.sub.2).sub.mCH.sub.2OH
) is available from Solvay Solexis, Inc. of Italy.
[0096] Hydroxyethyl acrylate (HEA) is available from Sigma Aldrich
of Milwaukee, Wis.
[0097] H.sub.2NCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3 is
available from Sigma Aldrich of Milwaukee, Wis.
[0098] HSCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3 is available
from Sigma Aldrich of Milwaukee, Wis.
[0099] 2-isocyanato-ethyl-methacrylate ("IEM")
(CH.sub.2.dbd.C(CH3)CO.sub.2CH.sub.2CH.sub.2NCO), is available from
Sigma Aldrich of Milwaukee, Wis.
[0100] The amines, 2-amino-2-ethyl-1,3-propane diol, and
1,1-bis-(hydroxyethyl)-1,3 aminopropane were obtained from
Sigma-Aldrich of Milwaukee, Wis.
[0101] Acryloyl chloride was obtained from Sigma-Aldrich of
Milwaukee Wis.
[0102] The UV photoinitiator, 1-hydroxycyclohexyl phenyl ketone
used was obtained from Ciba Specialty Products, Tarrytown, N.Y. and
sold under the trade designation "Irgacure 184."
[0103] The photoinitiator
2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one used was
obtained from Ciba Specialty Products, Tarrytown, N.Y. and sold
under the trade designation "Irgacure 907."
[0104] Methyl perfluorobutyl ether (HFE 7100) was obtained from 3M
Company, St. Paul, Minn.
[0105] Dibutyltin dilaurate (DBTDL) was obtained from Sigma Aldrich
of Milwaukee, Wis.
B. Preparation of Experimental Materials
[0106] Unless otherwise noted, "MW" refers to molecular weight and
"EW" refers to equivalent weight. Further, ".degree. C." may be
used interchangeably with "degrees Celsius" and "mol" refers to
moles of a particular material and "eq" refers to equivalents of a
particular material. Further, "Me" constitutes a methyl group and
may be used interchangeably with
Preparation No. 1. Preparation of HFPO--C(O)CH.sub.3
[0107] As used in the examples, "HFPO--" refers to the end group
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)-- wherein a has average
values of about 4.41, 6.2, 6.85, and 8.07. The material
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)COOCH.sub.3(HFPO--C(O)OCH.sub.3-
) can be prepared according to the method reported in U.S. Pat. No.
3,250,808 (Moore et al.), the disclosure of which is incorporated
herein by reference, with purification by fractional
distillation.
Preparation No. 2. Preparation of HFPO diol
HFPO--C(O)NHCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2OH).sub.2(HFPODO,
MW about 1341)
[0108] To a 500 ml 3-necked flask equipped with a stir bar and
reflux condenser was charged 100 g (MW about 1210.6, 0.0826 mol)
HFPO--C(O)OCH.sub.3, and 13.40 g (MW=162.2, 0.0826 mol)
H.sub.2NCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2OH).sub.2. The
mixture was reacted neat at 130 degrees Celsius for 6 hours. From
Fourier Transform Infrared Spectroscopy (FTIR) analysis, the amide
--C(O)NH-- was formed as the ester signal (--CO.sub.2--)
disappeared. The desired product,
HFPO--C(O)NHCH.sub.2CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2OH).sub.2 was
obtained as a viscous yellow liquid after concentration at 55
degrees Celsius under aspirator vacuum.
Preparation No. 3. Preparation of
HFPO--C(O)N(H)C(CH.sub.2OH).sub.2CH.sub.2CH.sub.3 Starting
Material
[0109] To a 500 ml 3-necked flask equipped with a stir bar and
reflux condenser was charged 11.91 g (0.1 mol)
H.sub.2NC(CH.sub.2OH).sub.2CH.sub.2CH.sub.3 and 60 g
tetrahydrofuran ("THF"). Next via dropping funnel was added 121.1 g
(0.1 mol) HFPO--C(O)OCH.sub.3 over about 80 minutes at a bath
temperature of about 85 degrees Celsius. The reaction was cloudy at
first, but became clear about 1 hour into the reaction. After
addition was complete, the heating bath was shut off and the
reaction was allowed to cool for three days. The material was
concentrated at 55 degrees Celsius under aspirator vacuum to yield
130.03 g of a light colored syrup. NMR analysis showed the product
to be an 87:13 mixture of the structures I and II as follows:
##STR2## Preparation No. 4. Preparation of
HFPO--C(O)NHCH.sub.2CH.sub.2OH of Different Molecular Weights
[0110] HFPO--C(O)N(H)CH.sub.2CH.sub.2OH of different molecular
weights (938.5, 1344, and 1547.2) were made by a procedure similar
to that described in U.S. Publication No. 2004-0077775 (Docket
Number 57823), entitled "Fluorochemical Composition Comprising a
Fluorinated Polymer and Treatment of a Fibrous Substrate
Therewith," filed on May 24, 2002, for Synthesis of HFPO-oligomer
alcohols, substituting
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)C(O)OCH.sub.3 with
a=4.41, 6.85, and 8.07 respectively, for
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)C(O)CH.sub.3 with
a=6.2.
C. General Procedure-Synthesis of Perfluoropolyether Urethane
Multiacrylate
Preparation No. 5. Preparation of Des N100/0.66 PET3A/0.33 HFPO
[0111] A 500 ml roundbottom flask equipped with magnetic stir bar
was charged with 25.0 g (0.131 eq, 191 EW) Des N100, 43.13 g (0.087
eq, 494.3 EW) of Sartomer SR444C, 25.3 mg of MEHQ, and 126.77 g
methyl ethyl ketone (MEK). The reaction was swirled to dissolve all
the reactants, the flask was placed in a oil bath at 60 degrees
Celsius, and fitted with a condenser under dry air. Two drops of
dibutyltin dilaurate was added to the reaction. After 1 hour, 58.64
g (0.0436 eq, 1344 EW)
F(CF(CF.sub.3)CF.sub.2O).sub.6.85CF(CF.sub.3)C(O)NHCH.sub.2CH.sub.2OH
was added to the reaction via addition funnel over about 75
minutes. The reaction was monitored by FTIR and showed a small
isocyanate absorption at 2273 cm.sup.-1 after about 5 hours of
reaction, but no isocyanate absorption at 7.5 hours of reaction.
The material was used as a 50% solids solution in MEK. The HFPO
multiacrylate urethanes preparations shown in Table 1 below, listed
as Preparation Nos. 5.1 through 5.19 respectively, were all made
according to this general procedure, using the appropriate mole
fractions of materials noted in the table. These preparations were
then used to verify the inventive formulations of the present
invention as used in hardcoat 18. TABLE-US-00001 TABLE 1
Perfluoropolyether Urethane Multiacrylates Isocyanate used (set
Mole Preparation at 100 Mole percent percent Number NCO in all
cases PET3A Mole percent HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW 1344)
5.1 Des N100 95 5 5.2 Des N100 85 15 5.3 Des N100 75 25 5.4 Des
N100 66.6 33.3 5.5 Des N100 50 50 5.6 Des N100 33.3 66.6 5.7 Des
N100 5 95 5.8 Des N3300 85 15 5.9 Des N3300 75 25 5.10 Des N3300
66.6 33.3 5.11 Des N3300 50 50 5.12 IPDI 75 25 5.13 Des TPLS2294 85
15 5.14 Des N3600 85 15 Mole percent
HFPO--C(O)NH(CH.sub.2).sub.3NHCH.sub.3 (See Preparation number 22)
5.15 Des N100 85 15 Mole percent HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW
938.5) 5.16 Des N100 85 15 5.17 Des N100 75 25 Mole percent
HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW 1547.2) 5.18 Des N100 85 15 5.19
Des N100 75 25
Preparation No. 6. Preparation of Des N100/0.90 PET3A/0.15 HFPO
[0112] A 500 ml roundbottom 2-necked flask equipped with magnetic
stir bar was charged with 25.00 g (0.131 eq, 191 EW) Des N100,
26.39 g (0.0196 eq, 1344 EW) F(CF(CF.sub.3)CF.sub.2O).sub.6.85
CF(CF.sub.3)C(O)NHCH.sub.2CH.sub.2OH, and 109.62 g MEK, and was
swirled to produce a homogeneous solution. The flask was placed in
an 80 degrees Celsius bath, charged with 2 drops of dibutyltin
dilaurate catalyst, and fitted with a condenser. The reaction was
cloudy at first, but cleared within two minutes. At about 1.75
hours, the flask was removed from the bath and 2.42 g of MEK was
added to compensate for lost solvent. A 2.0 g sample was removed
from the flask, leaving (1-(2.0/161.01) or 0.9876 weight fraction,
of the reaction, and 57.51 g (98.76% of 58.23 g) (0.116 mol, 494.3
equivalent weight) PET3A was added to the reaction, which was
placed in a 63 degrees Celsius bath. At about 5.25 hours FTIR
showed no isocyanate absorption at 2273 cm.sup.-1, and 0.56 g MEK
was added to compensate for solvent lost to bring the material to
50% solids.
Preparation No.7. Preparation of Des N100/0.90 HEA/0.10 HFPO
[0113] By a procedure similar to that for Preparation 5.1 shown in
Table 1 above, 28.34 g (0.1484 eq) Des N100, 19.94 g (0.148 eq)
F(CF(CF.sub.3) CF.sub.2O).sub.6.85
CF(CF.sub.3)C(O)NHCH.sub.2CH.sub.2OH, in 63.8 g MEK, with 2 drops
of DBTDL, 0.03 g BHT were reacted for 1 hour, followed by addition
of 15.51 g (0.1336 eq) HEA to provide, after reaction overnight,
the desired material.
Preparation No. 8. Preparation of Des
N100/HFPO--C(O)NHCH.sub.2CH.sub.2OH/MeFBSE/PET3A (in 30/10/10/10
Ratio):
[0114] A 120 ml bottle was charged with 5.73 g Des N100 (EW about
191, about 30 milliequivalents NCO), 3.57 g MeFBSE (MW=357, 10
milliequivalents OH), 13.44 g HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW
about 1344, 10 milliequivalents OH), 4.94 g PET3A (EW about 494.3,
about 10 milliequivalents OH), 5 drops of dibutyltin dilaurate
catalyst and 42 g MEK (about 40% solid) under nitrogen. The
solution was reacted at 70 degrees Celsius in an oil bath with a
magnetic stir bar for 20 hours after sealing the bottle. A clear
solution was obtained after reaction, which showed no unreacted
--NCO signal in FTIR analysis.
Preparation No. 9. Preparation of Des
N100/HFPO--C(O)NHCH.sub.2CH.sub.2OH/MeFBSE/PET3A (in 40/10/10/20
Ratio):
[0115] A 120 ml bottle was charged with 7.64 g Des N100 (EW about
191, about 40 milliequivalents NCO), 3.57 g MeFBSE (MW=357, 10
milliequivalents OH), 13.44 g HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW
about 1344, 10 milliequivalents OH), 9.89 g PET3A (EW about 494.3,
about 20 milliequivalents OH), 5 drops of dibutyltin dilaurate
catalyst and 52 g MEK (about 40% solid) under nitrogen. The
solution was reacted at 70 degrees Celsius in an oil bath with a
magnetic stir bar for 20 hours after sealing the bottle. A clear
solution was obtained after reaction, which showed no unreacted
--NCO signal in FTIR analysis.
Preparation No. 10. Preparation of Des
100/C.sub.6F.sub.13C.sub.2H.sub.4OH/PET3A (in 20/10/10 Ratio)
[0116] A 120 ml bottle was charged with 3.82 g Des N100 (EW about
191, about 20 milliequivalents NCO), 3.64 g
C.sub.6F.sub.13C.sub.2H.sub.4OH (MW=363, 10 milliequivalents OH),
4.94 g PET3A (EW about 494.3, about 10 milliequivalents OH), 3
drops of dibutyltin dilaurate catalyst and 19 g MEK (about 40%
solid) under nitrogen. The solution was reacted at 70 degrees
Celsius in an oil bath with a magnetic stir bar for 20 hours after
sealing the bottle. A clear solution was obtained after reaction,
which showed no unreacted --NCO signal in FTIR analysis.
Preparation No. 11. Preparation of Des
100/HO(CH.sub.2).sub.10OH/HFPO--C(O)NHCH.sub.2CH.sub.2OH/PET3A (in
60/20/15/25 Ratio)
[0117] A 120 ml bottle was charged with 11.46 g Des N100 (EW about
191, about 60 milliequivalents NCO), 1.74 g HO(CH.sub.2).sub.10OH
(MW=174, 20 milliequivalents OH), 20.16 g
HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW about 1344, 15 milliequivalents
OH), 12.36 g PET3A (EW about 494.3, about 25 milliequivalents OH),
5 drops of dibutyltin dilaurate catalyst and 106 g MEK (about 30%
solid) under nitrogen. The solution was reacted at 70 degrees
Celsius in an oil bath with a magnetic stir bar for 20 hours after
sealing the bottle. A clear solution was obtained after reaction,
which showed no unreacted --NCO signal in FTIR analysis.
Preparation No. 12. Preparation of Des
N100/FBSEE/HFPO--C(O)NHCH.sub.2CH.sub.2OH/PET3A (in 30/10/7.5/12.5
Ratio)
[0118] A 120 ml bottle was charged with 5.73 g Des N100 (EW about
191, about 30 milliequivalents NCO), 1.94 g FBSEE (MW=387, 10
milliequivalents OH), 10.08 g HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW
about 1344, 7.5 milliequivalents OH), 6.18 g PET3A (EW about 494.3,
about 12.5 milliequivalents OH), 5 drops of dibutyltin dilaurate
catalyst and 56 g MEK (about 30% solid) under nitrogen. The
solution was reacted at 70 degrees Celsius in an oil bath with a
magnetic stir bar for 20 hours after sealing the bottle. A clear
solution was obtained after reaction, which showed no unreacted
--NCO signal in FTIR analysis.
Preparation No. 13. Preparation of Des N3300/HFPODO/PET3A (in
30/10/20 Ratio)
[0119] A 240 ml bottle was charged with 5.79 g Des N3300 (EW about
193, about 30 milliequivalents NCO), 6.71 g HFPODO (MW about 1341,
10 milliequivalents OH), 9.89 g PET3A (EW about 494.3, about 20
milliequivalents OH), 5 drops of dibutyltin dilaurate catalyst and
52 g MEK (about 30% solid) under nitrogen. The solution was reacted
at 70 degrees Celsius in an oil bath with a magnetic stir bar for
10 hours after sealing the bottle. There was a small amount of
precipitate formed upon standing at room temperature. FTIR analysis
showed no unreacted --NCO signal.
Preparation No. 14. Preparation of Des
N3300/HFPODO/HFPO--C(O)NHCH.sub.2CH.sub.2OH/PET3A (in 30/10/5/15
Ratio)
[0120] A 240 ml bottle was charged with 5.79 g Des N3300 (EW about
193, about 30 milliequivalents NCO), 6.71 g HFPODO (MW about 1341,
10 milliequivalents OH), 6.72 g HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW
about 1344, 5 milliequivalents OH), 7.42 g PET3A (EW about 494.3,
about 15 milliequivalents OH), 5 drops of dibutyltin dilaurate
catalyst, 27 g MEK and 10 g C.sub.4F.sub.9OCH.sub.3 (about 20%
solid) under nitrogen. The solution was reacted at 70 degrees
Celsius in an oil bath with a magnetic stir bar for 10 hours after
sealing the bottle. Separation into two liquid phases occurred upon
standing at room temperature. Addition of more
C.sub.4F.sub.9OCH.sub.3 produced a clear homogeneous solution at
about 17% solids. FTIR analysis showed no unreacted --NCO
signal.
Preparation No. 15. Preparation of Des N3300/HFPODO/MeFBSE/PET3A
(in 30/10/5/15 Ratio)
[0121] A 120 ml bottle was charged with 5.79 g Des N3300 (EW about
191, about 30 milliequivalents NCO), 6.71 g HFPODO (MW about 1341,
10 milliequivalents OH), 1.79 g MeFBSE (MW=357, 5 milliequivalents
OH), 7.42 g PET3A (EW about 494.3, about 15 milliequivalents OH), 5
drops of dibutyltin dilaurate catalyst and 51 g MEK (about 30%
solid) under nitrogen. The solution was reacted at 70 degrees
Celsius in an oil bath with a magnetic stir bar for 10 hours after
sealing the bottle. A clear solution was obtained at 70 degrees
Celsius after reaction, but there was a small amount of precipitate
formed upon standing at room temperature. FTIR analysis showed no
unreacted --NCO signal.
Preparation No. 16. Preparation of Des
N3300/Fox-Diol/HFPO--C(O)NHCH.sub.2CH.sub.2OH/PET3A (in 30/10/5/15
Ratio)
[0122] A 240 ml bottle was charged with 5.79 g Des N3300 (EW about
191, about 30 milliequivalents NCO), 6.71 g Fox-Diol (MW about
1341, 10 milliequivalents OH), 6.72 g
HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW about 1344, 5 milliequivalents
OH), 7.40 g PET3A (EW about 494.3, about 15 milliequivalents OH), 5
drops of dibutyltin dilaurate catalyst, 56 g MEK and 50 g
C.sub.4F.sub.9OCH.sub.3 (about 19% solid) under nitrogen. The
solution was reacted at 70 degrees Celsius in an oil bath with a
magnetic stir bar for 10 hours after sealing the bottle. A clear
solution was obtained after reaction. FTIR analysis showed no
unreacted --NCO signal.
Preparation No. 17. Preparation of Des N3300/Fomblin Zdol/PET3A (in
30/10/20 Ratio)
[0123] A 240 ml bottle was charged with 5.79 g Des N3300 (EW about
191, about 30 milliequivalents NCO), 10.0 g Fomblin Zdol (MW about
2000, 10 milliequivalents OH), 9.89 g PET3A (EW about 494.3, about
20 milliequivalents OH), 5 drops of dibutyltin dilaurate catalyst,
63 g MEK and 40 g C.sub.4F.sub.9OCH.sub.3 (about 18% solid) under
nitrogen. The solution was reacted at 70 degrees Celsius in an oil
bath with a magnetic stir bar for 10 hours after sealing the
bottle. A clear solution was obtained after reaction. FTIR analysis
showed no unreacted --NCO signal.
Preparation No. 18. Preparation of Des
N3300/HHA/HFPO--C(O)NHCH.sub.2CH.sub.2OH/PET3A (in 30/10/10/10
Ratio)
[0124] A 240 ml bottle was charged with 5.79 g Des N3300 (EW about
191, about 30 milliequivalents NCO), 6.14 g HHA (MW about 1228, 10
milliequivalents OH), 12.29 g HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW
about 1229, 10 milliequivalents OH), 4.93 g PET3A (EW about 494.3,
about 10 milliequivalents OH), 5 drops of dibutyltin dilaurate
catalyst, 85 g MEK and 25 g C.sub.4F.sub.9OCH.sub.3 (about 20%
solid) under nitrogen. The solution was reacted at 70 degrees
Celsius in an oil bath with a magnetic stir bar for 10 hours after
sealing the bottle. A clear solution was obtained after reaction.
FTIR analysis showed no unreacted --NCO signal.
Preparation No. 19. Preparation of
PAPI/HFPO--C(O)NHCH.sub.2CH.sub.2OH/PET3A (in 28/8/20 Ratio)
[0125] A 120 ml bottle was charged with 3.75 g PAPI (EW about 134,
about 28 milliequivalents NCO), 10.75 g
HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW about 1344, 8 milliequivalents
OH), 9.88 g PET3A (EW about 494.3, about 20 milliequivalents OH), 5
drops of dibutyltin dilaurate catalyst and 37 g MEK (about 40%
solid) under nitrogen. The solution was reacted at 70 degrees
Celsius in an oil bath with a magnetic stir bar for 5 hours after
sealing the bottle. A clear solution was obtained after reaction.
FTIR analysis showed no unreacted --NCO.
D. General Preparation of perfluoropolyether urethane
multiacrylates Containing trialkoxysilane Functionality
Preparation No. 20. Preparation of Des N100/0.75 PET3A/0.15
HFPO/0.15 H.sub.2N(CH.sub.2).sub.3Si(OCH.sub.3).sub.3
[0126] A 500 ml roundbottom flask equipped with stir bar was
charged with 25.00 g (0.1309 eq) Des N100, 103.43 g MEK, 2 drops of
DBTDL, 26.39 g (0.0196 eq) HFPO--C(O)NHCH.sub.2CH.sub.2OH, 1344
equivalent weight, and 0.05 g BHT, and placed in a 60 degrees
Celsius oil bath. After 1 hour, 3.52 g (0.0196 eq)
H.sub.2N(CH.sub.2).sub.3Si(OCH.sub.3).sub.3 was added to the
reaction, followed in 10 minutes by the addition of 48.52 g (0.0982
eq, 494.3 equivalent weight) SR444C. The reaction showed no
residual isocyanate by FTIR after a total reaction time of 5.75
hours.
[0127] The preparation of other perfluoropolyether urethane
multiacrylates containing trialkoxysilane functionality was done by
a similar procedure, substituting the appropriate amounts of
materials, and are summarized in Table 2 as Preparation Nos. 20.1
through 20.4: TABLE-US-00002 TABLE 2 Isocyanate used (set Mole Mole
percent Preparation at 100 Mole percent percent Mole percent
H.sub.2N(CH.sub.2)3- Number NCO in all cases) PET3A
HFPO--C(O)NHCH.sub.2CH.sub.2OH Si(OCH.sub.3).sub.3 20.1 Des N100 75
15 15 20.2 Des N100 60 15 30 20.3 Des N100 45 15 45 20.4 Des N100
30 15 60
Preparation No. 21. Preparation of Des
N3300HFPO--C(O)NHCH.sub.2CH.sub.2OH/HSC.sub.3H.sub.6Si(OCH.sub.3).sub.3/P-
ET3A (in 30/8/2/20 Ratio)
[0128] A 240 ml bottle was charged with 5.79 g Des N3300 (EW about
193, about 30 milliequivalents NCO), 9.83 g
HFPO--C(O)NHCH.sub.2CH.sub.2OH (MW about 1229, 8 milliequivalents
OH), 0.39 g HSC.sub.3H.sub.6Si(OMe).sub.3 (MW=196, 2
milliequivalents SH), 5 drops of dibutyltin dilaurate catalyst, 40
g MEK and 20 g C.sub.4F.sub.9OCH.sub.3 under nitrogen. The solution
was reacted at 70 degrees Celsius in an oil bath with a magnetic
stir bar for 2 hours after sealing the bottle. Then, 4.46 g PET3A
(EW about 494.3, about 20 milliequivalents OH) was added at room
temperature under nitrogen. The solution was allowed to react for
another 6 hours at 70 degrees Celsius. A clear solution was
obtained after reaction, which showed no unreacted --NCO signal in
FTIR analysis.
Preparation No. 22. Preparation of
HFPO--C(O)NHCH.sub.2CH.sub.2CH.sub.2NHCH.sub.3 Starting
material
[0129] A 1-liter round-bottom flask was charged with 291.24 g
(0.2405 mol) of HFPO--C(O)OCH.sub.3 and 21.2 g (0.2405 mol)
N-methyl-1,3-propanediamine, both at room temperature, resulting in
a cloudy solution. The flask was swirled and the temperature of the
mixture rose to 45 degrees Celsius, and to give a water-white
liquid, which was heated overnight at 55 degrees Celsius. The
product was then placed on a rotary evaporator at 75 degrees
Celsius and 28 inches of Hg vacuum to remove methanol, yielding
301.88 g of a viscous slightly yellow liquid, nominal molecular
weight is equal to 1267.15 g/mol.
Preparation No. 23. Preparation of
HFPO--C(O)NHC(CH.sub.2CH.sub.3)(CH.sub.2OC(.dbd.O)NHC.sub.2H.sub.4OC(O)C(-
CH.sub.3).dbd.CH.sub.2).sub.2
[0130] A 240 ml bottle was charged with 6.49 g
HFPO--C(O)NHC(CH.sub.2CH.sub.3)(CH.sub.2OH).sub.2 (1298.5 MW, 5
mmol) ("Preparation No. 3"), 1.55 g IEM
(OCNC.sub.2H.sub.4OC(O)C(CH.sub.3).dbd.CH.sub.2, MW=155, 10 mmol),
3 drops of dibutyltin dilaurate catalyst, 50 mg BHT, 32 g ethyl
acetate and 10 g C.sub.4F.sub.9OCH.sub.3. The solution was reacted
at 70 degrees Celsius in an oil bath with a magnetic stir bar for 8
hours after sealing the bottle. A clear solution was obtained after
reaction, which showed no unreacted --NCO by in FTIR analysis,
providing a solution of the product
HFPO--C(O)NHC(CH.sub.2CH.sub.3)(CH.sub.2OC(.dbd.O)NHC.sub.2H.sub.4OC(O)C(-
CH.sub.3).dbd.CH.sub.2).sub.2.
Preparation No. 24. Preparation of
HFPO--C(O)NHCH.sub.2CH.sub.2OC(.dbd.O)NHC.sub.2H.sub.4OC(O)C(CH.sub.3).db-
d.CH.sub.2) (HFPO--IEM)
[0131] A 120 ml bottle was charged with 71.20 g (MW 1229, 57.9
mmol) HFPO--C(O)NHC.sub.2H.sub.4OH, 9.0 g of
CH.sub.2.dbd.C(CH.sub.3)CO.sub.2C.sub.2H.sub.4NCO (MW=155, 58
mmol), 52 g EtOAc, 3 drops of DBTDL and 1.5 mg of phenothiazine
under nitrogen. The solution was heated in a oil bath at 70 degrees
Celsius for 6 hours with a magnetic stirring after sealing the
bottle. Fourier Transform Infrared Spectroscopy (FTIR) analysis
indicated no remaining isocyanate.
E. Test Methods
[0132] Steel Wool Testing: The abrasion resistance of the cured
films was tested cross-web to the coating direction by use of a
mechanical device capable of oscillating cheesecloth or steel wool
fastened to a stylus (by means of a rubber gasket) across the
film's surface. The stylus oscillated over a 10 cm wide sweep width
at a rate of 3.5 wipes/second wherein a "wipe" is defined as a
single travel of 10 cm. The stylus had a flat, cylindrical geometry
with a diameter of 1.25 inch (3.2 cm). The device was equipped with
a platform on which weights were placed to increase the force
exerted by the stylus normal to the film's surface. The cheesecloth
was obtained from Summers Optical, EMS Packaging, a subdivision of
EMS Acquisition Corp., Hatsfield, Pa. under the trade designation
"Mil Spec CCC-c-440 Product #S12905". The cheesecloth was folded
into 12 layers. The steel wool was obtained from Rhodes-American, a
division of Homax Products, Bellingham, Wash. under the trade
designation "#0000-Super-Fine" and was used as received. A single
sample was tested for each example, with the weight in grams
applied to the stylus and the number of wipes employed during
testing reported.
[0133] Taber Testing: The Taber test was run according to ASTM
D1044-99 using CS-10 wheels.
[0134] Contact Angle: The coatings were rinsed for 1 minute by hand
agitation in IPA before being subjected to measurement of water and
hexadecane contact angles. Measurements were made using as-received
reagent-grade hexadecane (Aldrich) and deionized water filtered
through a filtration system obtained from Millipore Corporation
(Billerica, Mass.), on a video contact angle analyzer available as
product number VCA-2500XE from AST Products (Billerica, Mass.).
Reported values are the averages of measurements on at least three
drops measured on the right and the left sides of the drops. Drop
volumes were 5 .mu.L for static measurements and 1-3 .mu.L for
advancing and receding. For hexadecane, only advancing and receding
contact angles are reported because static and advancing values
were found to be nearly equal.
[0135] Surface Smoothness (Dewetting): For some of the tables
below, a visual inspection was made regarding the smoothness of the
applied dry film. While the measurement of smoothness by visual
inspection is a subjective determination, a smooth film, for the
purposes of the present invention, is deemed to be a surface layer
that is substantially continuous and free of visible defects in
reflected light as observed by visual observation of the coating
surface at a wide variety of possible angles. Typically, visual
observation is accomplished by looking at the reflection of a light
source from the coating surface at an angle of about 60 degrees
from perpendicular. Visual defects that may be observed include but
are not limited to pock marks, fish eyes, mottle, lumps or
substantial waviness, or other visual indicators known to one of
ordinary skill in the art in the optics and coating fields. Thus, a
"rough" surface as described below has one or more of these
characteristics, and may be indicative of a coating material in
which one or more components of the composition are incompatible
with each other. Conversely, a substantially smooth coating,
characterized below as "smooth" for the purpose of the present
invention, presumes to have a coating composition in which the
various components, in the reacted final state, form a coating in
which the components are compatible or have been modified to be
compatible with one another and further has little, if any, of the
characteristics of a "rough" surface.
[0136] The surfaces may also be classified for dewetting as "good,"
"very slight" (v.sl), "slight" (sl), "fair," or "poor." A "good"
surface meaning a substantially smooth surface having little
dewetting. A "very slight," slight", or "fair" categorization means
that the surface has an increasing portion of defects but is still
substantially acceptable for smoothness. A "poor" surface has a
substantial amount of defects, indicating a rough surface that has
a substantial amount of dewetting.
F. Experiments
[0137] The ceramer hardcoat ("HC-1") used in the examples was made
as described in column 10, line 25-39 and Example 1 of U.S. Pat.
No. 5,677,050 to Bilkadi, et al.
Experiment 1
[0138] Solutions as generally described in Tables 3-5 below were
prepared at 30% solids in a solvent blend of 1:1 isopropanol:ethyl
acetate and coated at a dry thickness of about 4 microns using a
number 9 wire wound rod onto 5-mil Melinex 618 film. The coatings
were dried in an 80 degree Celsius oven for 1 minute and then
placed on a conveyer belt coupled to a ultraviolet ("UV") light
curing device and UV cured under nitrogen using a Fusion 500 watt H
bulb at 20 ft/min. The values reported in the Tables refer to the
percent solids of each component of the dried coating. The coatings
were then visually inspected for surface smoothness (dewetting).
The coatings were also tested for durability of ink repellency.
Durability was assessed using a modified Oscillating Sand Method
(ASTM F 735-94). An orbital shaker was used (VWR DS-500E, from VWR
Bristol, Conn.). A disk of diameter 85 mm was cut from the sample,
placed in a 16 ounce jar lid (jar W216922 from Wheaton, Millville,
N.J.), and covered with 50 grams of 20-30 mesh Ottawa sand (VWR,
Bristol, Conn.). The jar was capped and placed in the shaker set at
300 rpm for 15 minutes. After shaking, a Sharpie permanent marker
was used to draw a line across the diameter of the disk surface.
The portion of the ink line that did not bead up was measured. A
measure of 85 mm would be no repellency; a measure of 0 mm would be
perfect durability. Results are shown in Tables 3 and 4.
TABLE-US-00003 TABLE 3 Percentage Percentage HC-1 Preparation
Preparation Ink in coating number in coating Dewet Repel. 99.9 5.5
0.1 good 65 99.8 5.5 0.2 v. sl 53 99.7 5.5 0.3 fair 49 99.86 5.4
0.14 sl 51 99.72 5.4 0.28 sl 44 99.58 5.4 0.42 sl 40 99.7 5.3 0.3
good 35 99.4 5.3 0.6 v. sl 34 99.1 5.3 0.9 sl 31 99.9 5.11 0.1 good
65 99.8 5.11 0.2 v. sl 49 99.7 5.11 0.3 sl 50 99.86 5.10 0.14 good
60 99.72 5.10 0.28 good 37 99.58 5.10 0.42 v. sl 38 99.7 5.9 0.3
good 42 99.4 5.9 0.6 good 43 99.1 5.9 0.9 v. sl 47
[0139] Selected coatings, before sand testing, from another coating
run were analyzed for contact angles and the results are shown in
Table 4. TABLE-US-00004 TABLE 4 Water Hexadecane Preparation Wt %
static/Adv/Rec Adv/Rec number in HC-1 CA (deg) CA (deg) 5.3 0.3
108/119/91 71/65 5.3 0.6 109/120/90 72/67 5.5 1.2 108/120/90 73/67
5.9 1.2 109/121/89 74/67 4.11 1.2 108/118/85 74/64
[0140] Another set of examples was run according to the same
procedure as examples in Table 1. The results are shown in Table 5.
TABLE-US-00005 TABLE 5 Percentage Percentage HC-1 in Preparation
Preparation Ink coating number in coating Smoothness Repellency
99.8 5.3 0.2 good 32 99.7 5.3 0.3 good 22 99.6 5.3 0.4 v. sl 23
99.76 5.2 0.24 good 46 99.52 5.2 0.48 good 26 99.33 5.2 0.67 good
42 99.8 5.10 0.2 good 25 99.7 5.10 0.3 good 42 99.6 5.10 0.4 v. sl
42 99.64 5.9 0.36 good 26 99.43 5.9 0.57 good 12 99.22 5.9 0.78
good 33 99.76 5.8 0.24 good 47 99.52 5.8 0.48 good 18 99.33 5.8
0.67 v. sl 33
[0141] Table 6 shows the results of another set of examples that
was run at two levels of additives in an HC-1 hardcoat in which the
sand test was run for 25 minutes at 300 rpm. The examples were run
according to the same procedure as examples in Table 1 described
above. TABLE-US-00006 TABLE 6 Percentage Percentage HC-1 in
Preparation Preparation Ink coating number in coating Smoothness
Repellency 99.8 9 0.2 sl 20 99.0 9 1.0 sl 10 99.8 8 0.2 good 29
99.0 8 1.0 poor 25 99.8 10 0.2 good 38 99.0 10 1.0 good 30 99.8 11
0.2 good 40 99.0 11 1.0 fair 20 99.8 12 0.2 good 36 99.0 12 1.0
poor 22 99.8 19 0.2 good 20 99.0 19 1.0 sl 49 99.8 5.2 0.2 good
5
[0142] Table 7 shows the results of another set of examples that
was run at two levels of additives in an HC-1 hardcoat in which the
sand test was run for 25 minutes at 300 rpm and in a separate set
for 35 minutes at 300 rpm. The examples were run according to the
same procedure as examples in Table 1 described above.
TABLE-US-00007 TABLE 7 % Prepar- Percentage Repellency Repellency
HC-1 in ation Preparation Smooth- 25 min at 35 min at coating
number in coating ness 300 rpm 300 rpm 99.5 5.2 0.5 good 0 99.5 5.2
0.5 good 10 99.8 5.1 0.2 good 35 99.0 5.1 1.0 good 0 99.0 5.1 1.0
good 36 99.8 5.6 0.2 sl 0 99.0 5.6 1.0 poor 0 99.8 5.7 0.2 poor 62
99.0 5.7 1.0 poor 26 99.8 5.12 0.2 good 0 99.0 5.12 1.0 fair 0 99.8
5.12 0.2 good 54 99.8 5.13 0.2 good 0 99.0 5.13 1.0 good 0 99.0
5.13 1.0 good 38 99.8 5.14 0.2 good 0 99.0 5.14 1.0 good 0 99.0
5.14 1.0 good 35 99.8 5.15 0.2 good 5 99.0 5.15 1.0 good 0 99.0
5.15 1.0 slight 11 99.8 5.3 0.2 good 0 99.2 5.3 1.0 sl 0 99.5 5.3
0.5 good 25 99.8 5.16 0.2 good 10 99.0 5.16 1.0 good 0 99.0 5.16
1.0 good 38 99.8 5.17 0.2 good 0 99.0 5.17 1.0 v. sl 0 99.5 5.17
0.5 good 25 99.8 5.18 0.2 good 0 99.0 5.18 1.0 sl 0 99.8 5.18 0.2
good 47 99.8 5.19 0.2 good 0 99.0 5.19 1.0 sl 0 99.8 5.19 0.2 sl 36
99.8 8 0.2 good 27 98.5 10 1.5 good 30
[0143] An example set illustrating the use of perfluoropolyether
diols in the invention was run according to the same procedure as
examples in Table 1. These results are shown in Table 8.
TABLE-US-00008 TABLE 8 Ink Ink % Prepar- Percentage repellency
repellency HC-1 in ation Preparation Smooth- 35 min at 55 min at
coating Number in coating ness 300 rpm 300 rpm 98.8 13 0.2 good 37
99.0 13 1.0 v. sl 27 99.5 14 0.5 v. sl 0 26 99.8 15 0.2 good 34
99.0 15 1.0 v. sl 31 99.8 16 0.2 good 0 28 99.0 16 1.0 good 0 26
99.8 17 0.2 good 26 99.0 17 1.0 v. sl 34
[0144] Another set illustrating the use of a multi acrylate diol in
the invention, and a thiol functional trialkoxysilane was run
according to the same procedure as examples in Table 1. These
results are shown in Table 9. TABLE-US-00009 TABLE 9 Percentage
Percentage Ink repellency HC-1 in Preparation Preparation 40 min at
coating number in coating Smoothness 300 rpm 99.3 18 0.7 good 32
99.3 21 0.7 good 40 99.3 4.2 0.7 good 0
[0145] An example set illustrating the trialkoxysilane functional
perfluoropolyether urethane multiacrylates, a perfluoropolyether
urethane acrylate made using hydroxyethyl acrylate, and a
perfluoropolyether diol functionalized with isocyanatoethyl
methacrylate was run according to the same procedure as examples in
Table 1. These results are shown in Table 10. TABLE-US-00010 TABLE
10 Percentage Percentage Repellency HC-1 in Preparation Preparation
20 min at coating Number in coating Smoothness 300 rpm 99.6 20.1
0.4 good 0 99.6 20.2 0.4 good 0 99.6 20.3 0.4 good 0 99.6 20.4 0.4
good 0 99.6 7 0.4 good 0 99.6 23 0.4 good 0
[0146] A 30% solids (in a solvent blend of 1:1 isopropanol:ethyl
acetate) sample of 99.4% PET4A/0.6% Des N100/0.85 PET3A/0.15 HFPO
(Preparation 5.2) with 2% added Irgacure 907 was prepared. The
solution was coated and cured by the same procedure as above. The
smooth coating gave an ink repellency of 0 after a 20 minute sand
test at 300 rpm.
[0147] Another set of examples using a perfluoropolyether alcohol
functionalized with isocyanatoethyl methacrylate in combination
with a compatibilizer was run according to the same procedure as
examples in Table 1. The results are shown in Table 11.
TABLE-US-00011 TABLE 11 Percentage Prepar- Percentage Percentage
Repellency HC-1 in ation Preparation FBSEA in Smooth- 15 min. at
coating Number in coating coating ness 300 rpm 99.7 24 0.03 0
Dewet/ not run rough 97.67 24 0.03 2.3 good 25 94.97 24 0.03 5 good
0 90.97 24 0.03 9 good 33 85.97 24 0.03 14 good 33
[0148] Another experiment was run in which HC-1 was applied to the
5-mil Melinex 618 film with a metered, precision die coating
process. The hardcoat formulation with HC-1 and Des N100/0.85
PET3A/0.15 HFPO (Preparation 5.2) was diluted to 30 wt-% solids in
isopropanol and coated onto the 5-mil PET backing to achieve a dry
thickness of 5 microns. A flow meter was used to monitor and set
the flow rate of the material from a pressurized container. The
flow rate was adjusted by changing the air pressure inside the
sealed container which forces liquid out through a tube, through a
filter, the flow meter and then through the die. The dried and
cured film was wound on a take up roll.
[0149] The coatings were dried in a 10-foot oven at 100 degrees
Celsius, and cured with a 300-watt Fusion Systems H bulb at 100,
75, 50, and 25% power. The coating shown in Table 12 below was
evaluated in a series of tests. The sand test was run for 15
minutes at 300 rpm. The Steel Wool Test was run checking for damage
to the coating at 100, 250, 500, 750, and 1000 cycles. The results
are summarized in Table 12. Contact angles were also run on
selected samples before and after testing and these results are
shown in Table 13. TABLE-US-00012 TABLE 12 (Preparation Steel Wool
Taber testing Wt. % Number 5.2) UV (Cycles Taber testing Change in
haze from HC-1 in Weight % dose % Ink without % haze after initial
value in % coating in coating power repellency scratches) 500
cycles after 500 cycles 99.27 0.73 100 0 1000 10.83 10.51 99.27
0.73 75 0 1000 8.38 8.04 99.27 0.73 50 0 1000 11.05 10.62 99.27
0.73 25 0 1000 8.35 8.04
[0150] Selected coatings from Table 12 were tested for contact
angles with water and hexadecane, and are identified by the UV dose
% power used in curing the coatings. The results are summarized in
Table 13: TABLE-US-00013 TABLE 13 After 1000 After Sand Steel Wool
Initial Testing Samples Liquid Advancing/ Advancing/ Advancing/
used to Static/ Static/ Static/ test Receding Receding Receding UV
dose contact Contact Contact Contact % power angle angles angles
angles 100 Water 110/123/98 94/111/68 107/119/89 100 Hexadecane
--/72/64 --/61/49 --/69/62 25 Water 107/120/84 91/105/53 103/118/72
25 Hexadecane --/71/62 --/56/40 --/63/55
[0151] The present invention provides fluorocarbon- and
urethane-acrylate-containing additives that can be used in coating
compositions to provide coating layers having high surface energies
and smoothness.
[0152] These fluorocarbon- and urethane-acrylate-containing
additives are preferably introduced to conventional hard coating
materials and cured to form optical hard coating layers having
enhanced stain and ink repellency properties, adequate smoothness,
and improved durability. Further, optical hard coatings having
these additives do not need compatibilizers designed to enhance the
compatibility between a fluoropolymer additive and the conventional
hard coat material.
[0153] A transparent polyethylene terephthalate (PET) film obtained
from e.i. duPont de Nemours and Company, Wilmington, Del. under the
trade designation "Melinex 618" having a thickness of 5.0 mils and
a primed surface. A hardcoat composition substantially the same as
Example 3 of U.S. Pat. No. 6,299,799 (S-1) was coated onto the
primed surface with a metered, precision die coating process. The
hardcoat was diluted in IPA to 30 wt-% solids and coated onto the
5-mil PET backing to achieve a dry thickness of 5 microns.
[0154] A flow meter was used to monitor and set the flow rate of
the material from a pressurized container. The flow rate was
adjusted by changing the air pressure inside the sealed container
which forces liquid out through a tube, through a filter, the flow
meter and then through the die. The dried and cured film was wound
on a take up roll and used as the input backing for the coating
solutions described below.
[0155] The hardcoat coating and drying parameters were as follows:
TABLE-US-00014 Coating width: 6'' (15 cm) Web Speed: 30 feet (9.1
m) per minute Solution % Solids: 30.2% Filter: 2.5 micron absolute
Pressure Pot: 1.5 gallon capacity (5.7 l) Flow rate: 35 g/min Wet
Coating Thickness: 24.9 microns Dry Coating Thickness: 4.9 microns
Conventional Oven Temps: Zone 1 - 140.degree. F. (60.degree. C.)
Zone 2 - 160.degree. F. (53.degree. C.) Zone 3 - 180.degree. F.
(82.degree. C.) Each zone was 10 ft (3 m) in length.
[0156] The coating compositions of the surface layer were coated
onto the hardcoat layer of either the first or the second substrate
using a precision, metered die coater. For this step, a syringe
pump was used to meter the solution into the die. The solutions
were diluted with MEK to a concentration of 1% and coated onto the
hardcoat layer to achieve a dry thickness of 60 nm. The material
was dried in a conventional air flotation oven and then cured a 600
watt Fusion Systems bulb under nitrogen using the conditions show
below: TABLE-US-00015 Coating width: 4'' (10 cm) Web Speed: 20 feet
per minute Solution % Solids: 1.0% Pump: 60 cc Syringe Pump Flow
rate: 1.2 cc/min Wet Coating Thickness: 4.1 microns Dry Coating
Thickness: 60 nm Conventional Oven Temps: Zone 1 - 65.degree. C.
Zone 2 - 65.degree. C. Both zones at 10 ft (3 m) in length.
[0157] The following surface layer coatings were made and tested
for ink repellency after a sand test at 300 rpm for 15 min and for
initial water static contact angle. TABLE-US-00016 TABLE 14 Prepar-
Static water ation % Ink Contact angle TMPTA number HFPO Darocure
Repellency (range in (%) 6 (%) AEA 1173 loss degrees) 95 3.75 1.25
4 0 100-101 90 7.5 2.5 4 0 85 11.25 3.75 4 0 110-111 80 15 5 4 0 90
10 4 0 93-94 80 20 4 0 103-104
[0158] While the invention has been described in terms of preferred
embodiments, it will be understood, of course, that the invention
is not limited thereto since modifications may be made by those
skilled in the art, particularly in light of the foregoing
teachings.
* * * * *