U.S. patent application number 16/427814 was filed with the patent office on 2019-09-19 for blended release materials.
This patent application is currently assigned to 3M Innovative Properties Company. The applicant listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Maria A. Appeaning, Larry D. Boardman, Daniel Carvajal, Michael D. Determan, David J. Kinning, Kiu-Yuen Tse.
Application Number | 20190284432 16/427814 |
Document ID | / |
Family ID | 52293243 |
Filed Date | 2019-09-19 |
United States Patent
Application |
20190284432 |
Kind Code |
A1 |
Carvajal; Daniel ; et
al. |
September 19, 2019 |
BLENDED RELEASE MATERIALS
Abstract
Blended, release materials containing crosslinked silicones,
crosslinked fluorosilicones, and nonfunctional fluorosilicones are
described. Articles including release liners and adhesive articles
are also described, as are methods of making such blended release
materials and articles incorporating them.
Inventors: |
Carvajal; Daniel; (Edina,
MN) ; Boardman; Larry D.; (Woodbury, MN) ;
Kinning; David J.; (Woodbury, MN) ; Determan; Michael
D.; (Mahtomedi, MN) ; Tse; Kiu-Yuen;
(Woodbury, MN) ; Appeaning; Maria A.; (St. Paul,
MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
52293243 |
Appl. No.: |
16/427814 |
Filed: |
May 31, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15100688 |
Jun 1, 2016 |
10351730 |
|
|
PCT/US2014/070564 |
Dec 16, 2014 |
|
|
|
16427814 |
|
|
|
|
61916466 |
Dec 16, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 83/08 20130101;
C09J 183/04 20130101; C09J 2483/005 20130101; C08G 77/24 20130101;
C08G 77/20 20130101; C09D 183/08 20130101; C09D 183/04 20130101;
C09J 2427/00 20130101; C09J 7/401 20180101; C09J 7/38 20180101;
C09J 183/08 20130101; C09J 2483/00 20130101; C09J 2483/006
20130101; C09J 2301/302 20200801; C08G 77/06 20130101; C08G 77/12
20130101; C08L 2205/03 20130101; C08L 2205/025 20130101; C08L 83/04
20130101; C09D 183/08 20130101; C08L 83/00 20130101; C08L 83/00
20130101; C08K 5/56 20130101; C08L 83/08 20130101; C08K 5/56
20130101; C08L 83/00 20130101; C08L 83/00 20130101; C09J 183/08
20130101; C08L 83/00 20130101; C08L 83/00 20130101 |
International
Class: |
C09D 183/04 20060101
C09D183/04; C09J 7/40 20060101 C09J007/40; C09D 183/08 20060101
C09D183/08; C09J 7/38 20060101 C09J007/38; C08G 77/20 20060101
C08G077/20; C08G 77/24 20060101 C08G077/24; C08L 83/08 20060101
C08L083/08; C08L 83/04 20060101 C08L083/04; C08G 77/06 20060101
C08G077/06 |
Claims
1. A composition comprising a blend of: (a) a functional,
non-fluorinated, silicone polymer comprising at least two
ethylenically unsaturated organic groups; (b) a functional
fluorosilicone polymer; and (c) a nonfunctional fluorosilicone
polymer.
2. The composition of claim 1, wherein the blend comprises at least
50 weight percent of the functional, non-fluorinated, silicone
polymer based on the total weight of (a) and (b).
3. The composition of claim 1, wherein the blend comprises at least
3 weight percent of the functional fluorosilicone polymer based on
the total weight of (a) and (b).
4. The composition of claim 1, wherein the blend comprises at least
1 part by weight of the nonfunctional fluorosilicone polymer per
100 parts by weight of (a) and (b).
5. The composition of claim 1, wherein a ratio of the vinyl
equivalent weight of the functional fluorosilicone polymer over the
vinyl equivalent weight of the functional non-fluorinated silicone
polymer is at least 1.
6. The composition of claim 5, wherein the ratio of the vinyl
equivalent weight of the functional fluorosilicone polymer to the
vinyl equivalent weight of the functional non-fluorinated silicone
polymer is from 2 to 20.
7. The composition of claim 1, wherein the nonfunctional
fluorosilicone polymer comprises one or more fluorinated groups
having two or more fluorinated carbon atoms.
8. The composition of claim 1, wherein the functional
fluorosilicone polymer comprises fluorinated groups comprising two
or more fluorinated carbon atoms.
9. The composition of claim 1, wherein the blend comprises: (a) at
least 80 to no greater than 95 weight percent based on the total
weight of (a) and (b) of the functional, non-fluorinated, silicone
polymer; (b) at least 5 to no greater than 20 weight percent based
on the total weight of (a) and (b) of the functional fluorosilicone
polymer, and wherein the functional fluorosilicone polymer
comprises at least two ethylenically-unsaturated groups; and (c) at
least 1 to no greater than 15 parts by weight of the nonfunctional
fluorosilicone polymer based on 100 parts by weight of (a) and
(b).
10. An adhesive article comprising a release liner comprising a
substrate; the cured release material according to claim 9 bonded
to at least a portion of at least one surface of the substrate; and
a silicone adhesive in contact with at least a portion of at least
one surface of the cured release material.
11. An adhesive article comprising: a substrate; a cured release
material bonded to at least a portion of at least one surface of
the substrate, wherein the cured release material comprises a
reaction product of a blend of (a) a functional, non-fluorinated,
silicone polymer comprising at least two ethylenically unsaturated
organic groups; (b) a functional fluorosilicone polymer; and (c) a
nonfunctional fluorosilicone polymer; and a silicone adhesive in
contact with at least a portion of at least one surface of the
cured release material.
12. The adhesive article of claim 11, wherein silicone adhesive
comprises a silicone block copolymer or an e-beam cured silicone
adhesive or a peroxide-cured silicone adhesive.
13. The adhesive article of claim 11, wherein the silicone adhesive
is a silicone polyurea adhesive.
14. The adhesive article of claim 11, wherein the silicone adhesive
is a polydiorganosiloxane-polyoxamide adhesive.
15. The adhesive article of claim 11, wherein the silicone adhesive
comprises a tackifier.
16. A method of forming an adhesive article comprising: applying an
uncured solventless silicone adhesive to a release liner and curing
the silicone adhesive, and wherein the release liner comprises a
substrate and a cured release material comprising a fluorosilicone
polymer bonded to at least a portion of at least one surface of the
substrate.
17. The method of claim 16, wherein the uncured silicone adhesive
further comprises a tackifier.
18. The method of claim 16, wherein the uncured silicone adhesive
comprises a silicone block copolymer, an e-beam curable silicone
adhesive, or a peroxide-cured silicone adhesive.
19. The method of claim 16, wherein the curing of the silicone
adhesive is performed using e-beam curing or peroxide-curing.
20. The method of claim 16, wherein the fluorosilicone polymer
comprises a reaction product of a blend of (a) a functional,
non-fluorinated, silicone polymer comprising at least two
ethylenically unsaturated organic groups; (b) a functional
fluorosilicone polymer; and (c) a nonfunctional fluorosilicone
polymer.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 15/100688, filed Jun. 1, 2016, which is a national stage filing
under 35 U.S.C. 371 of PCT/US2014/070564, filed Dec. 16, 2014,
which claims the benefit of U.S. application Ser. No. 61/916466,
filed Dec. 16, 2013, the disclosure of which is incorporated by
reference in its/their entirety herein.
FIELD
[0002] The present disclosure relates to high performance, blended,
release materials. Specifically, release materials containing
crosslinked silicones, crosslinked fluorosilicones, and
nonfunctional fluorosilicones are described. Articles including
release liners and adhesive articles are also described. The
present disclosure also relates to methods of making such blended
release materials and articles incorporating them.
SUMMARY
[0003] Briefly, in one aspect, the present disclosure provides a
composition comprising a blend of: (a) a functional,
non-fluorinated, silicone polymer; (b) a functional fluorosilicone
polymer; and (c) a nonfunctional fluorosilicone polymer.
[0004] In some embodiments, the blend comprises at least 50 weight
percent of the functional, non-fluorinated, silicone polymer based
on the total weight of (a) and (b), e.g., in some embodiments, the
blend comprises 65-97, e.g., 80 to 95 weight percent, inclusive, of
the functional, non-fluorinated, silicone polymer based on the
total weight of (a) and (b). In some embodiments, the blend
comprises at least 3, e.g., at least 5 weight percent of the
functional fluorosilicone polymer based on the total weight of (a)
and (b). For example, the blend often comprises 3 to 35 weight
percent, such as 4 to 30 weight percent, 5 to 20 weight percent, or
8 to 15 weight percent of the functional fluorosilicone polymer
based on the total weight of (a) and (b). In some embodiments, the
blend comprises at least 1 part by weight of the nonfunctional
fluorosilicone polymer per 100 parts by weight of (a) and (b). In
some embodiments, the blend comprises no greater than 30, e.g., no
greater than 15 parts by weight of the nonfunctional fluorosilicone
polymer per 100 parts by weight of (a) and (b).
[0005] In some embodiments, the functional, non-fluorinated,
silicone polymer comprises at least two ethylenically-unsaturated
organic groups. In some embodiments, the functional,
non-fluorinated, silicone polymer has a vinyl equivalent weight of
500 to 5000 grams per equivalent.
[0006] In some embodiments, the functional fluorosilicone polymer
comprises at least two ethylenically-unsaturated organic groups. In
some embodiments, the functional fluorosilicone polymer has a vinyl
equivalent weight of 500 to 40,000 grams per equivalent, for
example 1,000 to 20,000, e.g. 1,500 to 10,000 grams per equivalent.
In some embodiments, the ratio of the vinyl equivalent weight of
the functional fluorosilicone polymer over the vinyl equivalent
weight of the functional non-fluorinated silicone polymer is at
least 1, e.g., in some embodiments, the ratio of the vinyl
equivalent weight of the functional fluorosilicone polymer over the
vinyl equivalent weight of the functional non-fluorinated silicone
polymer is at least between 2 and 6, inclusive.
[0007] In some embodiments, the nonfunctional fluorosilicone
polymer comprises fluorinated groups comprising two or more
fluorinated carbon atoms, e.g., in some embodiments, the
fluorinated groups of the nonfunctional fluorosilicone polymer
comprise nonafluorohexyl groups i.e.,
--CH.sub.2CH.sub.2--C.sub.4F.sub.9.
[0008] In some embodiments, the functional fluorosilicone polymer
comprises fluorinated groups comprising two or more fluorinated
carbon atoms, e.g., in some embodiments, the fluorinated groups of
the functional fluorosilicone polymer comprise nonafluorohexyl
groups, i.e., --CH.sub.2CH.sub.2--C.sub.4F.sub.9.
[0009] In some embodiments, the composition further comprises at
least one of a silicone crosslinker and a fluorosilicone
crosslinker, e.g., at least one crosslinker comprising a silicon
bonded hydride group.
[0010] In another aspect, the present disclosure provides a cured
release material comprising the composition according to any of the
embodiments described, wherein the functional, non-fluorinated,
silicone polymer and the functional fluorosilicone polymer are
crosslinked. In some embodiments, the crosslinked functional,
non-fluorinated, silicone polymer comprises the reaction product of
the functional, non-fluorinated, silicone polymer and a silicone
crosslinker. In some the crosslinked functional fluorosilicone
polymer comprises the reaction product of the functional
fluorosilicone polymer and a fluorosilicone crosslinker.
[0011] In yet another aspect, the present disclosure provides a
release liner comprising a substrate and the cured release material
according to any of the embodiments bonded to at least a portion of
at least one surface of the substrate.
[0012] In another aspect, the present disclosure provides an
adhesive article comprising the release liner according to any of
the embodiments and an adhesive in contact with at least a portion
of at least one surface of the cured release material. In some
embodiments, the adhesive is a silicone adhesive, e.g., an e-beam
cured silicone adhesive, a silicone polyurea adhesive, or a
polydiorganosiloxane-polyoxamide adhesive.
[0013] In another aspect, the present disclosure provides a method
of forming a release article comprising: applying the composition
according to any of the embodiments to at least a portion of at
least one surface of a substrate, and crosslinking the functional,
non-fluorinated, silicone polymer and the functional fluorosilicone
polymer. In some embodiments, crosslinking the functional,
non-fluorinated, silicone polymer comprises reacting the
functional, non-fluorinated, silicone polymer with a silicone
crosslinker. In some embodiments, crosslinking the functional
fluorosilicone polymer comprises reacting the functional
fluorosilicone polymer with a fluorosilicone crosslinker.
[0014] In another aspect, the present disclosure provides a method
of forming an adhesive article comprising: applying an adhesive to
the release material of any of the embodiments. In some
embodiments, applying the adhesive comprises laminating a cured
adhesive to the release material. In some embodiments, applying the
adhesive comprises applying an uncured adhesive to the release
material and curing the adhesive.
[0015] In a further aspect, the present disclosure provides a
composition comprising a blend of: (a) at least 80 to no greater
than 95 weight percent based on the total weight of (a) and (b) of
a functional, non-fluorinated, silicone polymer comprising at least
two ethylenically-unsaturated groups; (b) at least 5 to no greater
than 20 weight percent, such as at least 8 and no greater than 15
weight percent, based on the total weight of (a) and (b) of a
functional fluorosilicone polymer comprising at least two
ethylenically-unsaturated groups; and (c) at least 1 to no greater
than 15 parts by weight of a nonfunctional fluorosilicone polymer
based on 100 parts by weight of (a) and (b).
[0016] The above summary of the present disclosure is not intended
to describe each embodiment of the present invention. The details
of one or more embodiments of the invention are also set forth in
the description below. Other features, objects, and advantages of
the invention will be apparent from the description and from the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates a release article according to some
embodiments of the present disclosure.
[0018] FIG. 2 illustrates an adhesive article according to some
embodiments of the present disclosure.
DETAILED DESCRIPTION
[0019] Pressure sensitive adhesives (PSAs) are an important class
of materials. Generally, PSAs adhere to a substrate with light
pressure (e.g., finger pressure) and typically do not require any
post-curing (e.g., heat or radiation) to achieve their maximum bond
strength. A wide variety of PSA chemistries are available. Silicone
PSAs offer one or more of the following useful characteristics:
adherence to low surface energy (LSE) surfaces, performance at high
and low temperature extremes, weathering resistance (including
resistance to ultraviolet (UV) radiation, oxidation, and humidity),
chemical resistance (e.g., solvents and plasticizers), and
resistance to biological substances (e.g., mold and fungi).
[0020] Unfortunately, finding suitable, yet cost-effective, release
materials has proven to be one of the major issues inhibiting the
widespread adoption of silicone pressure sensitive adhesives. For
example, few release materials provide stable, consistent, smooth
release of a wet-cast silicone adhesive. Since the adhesives
themselves are silicone based, traditional release liners based on
polydimethylsiloxane (PDMS) chemistries are generally ineffective.
For example, silicone adhesives such as e-beam cured silicone
adhesives (such as those described in U.S. Pat. No. 8,541,181
(Bresnick)), silicone polyurea adhesives (such as those described
in U.S. Pat. No. 7,078,093 (Sheridan)), and
polydiorganosiloxane-polyoxamide adhesives (such as those described
in WO 2011/082069 (Hays)), offer challenges in terms of obtaining
stable, consistent, smooth and cost-effective release.
[0021] Fluorinated release coatings have been used; however, the
selection is limited. The most common fluorinated release coatings
are fluorosilicone materials, i.e., silicone materials comprising
at least some fluorine atoms. However, commercially available
fluorosilicone release coatings are typically more expensive than
many common fluorinated materials as well as silicone release
materials.
[0022] Several approaches have been tried to provide
cost-effective, fluorosilicone-based release materials for use with
silicone PSAs. For example, U.S. Publication No. 2012-0219794-A1
("Fluorosilicone Blend Release Materials") describes release
materials containing blends of a functional fluorosiloxane polymer
with a functional non-fluorinated siloxane polymer. Also, U.S.
Publication No. 2011-0244226-A1 ("Blended Fluorosilicone Release
Materials") describes release materials containing blends of a
fluorosiloxane polymer with a linear fluoropolymer. While these
materials are suitable for use with a range of silicone-based
adhesives, there remains a need for more robust release
compositions, particularly for use with more aggressive, difficult
to release silicone-based PSAs.
[0023] Generally, the release materials of the present disclosure
comprise a blend of a functional, non-fluorinated silicone polymer;
a functional fluorosilicone polymer; and a nonfunctional
fluorosilicone polymer. Suitable additives such as crosslinkers may
also be present.
[0024] The term "vinyl equivalent weight" is used to describe
various polymers herein. As used herein, the "vinyl equivalent
weight" of a material, such as a polymer, refers to the quotient of
the mass of the reference material in grams and the mols of
ethylenically-unsaturated functional groups in the material. Thus,
a polymer sample having a mass of 5,000 grams and 2 mols of
ethylenically-unsaturated functional groups has a vinyl equivalent
weight of 5,000 divided by 2, or 2,500 grams. Generally, as the
vinyl equivalent weight of a polymer in a curable composition is
increased, the crosslink density of the composition after curing
will decrease.
[0025] The degree of polymerization of various polymers discussed
herein is often selected to provide polymers having a desired vinyl
equivalent weight. The vinyl equivalent weight of a polymer and the
degree of polymerization of the polymer are related; however, the
precise relationship between the two depends on the chemical
identity of each monomer unit in the polymer, including the
molecular weight of each polymerized monomer or co-monomer and the
number of olefin units in each polymerized monomer or co-monomer.
Thus, a person of skill in the art can readily provide a polymer
having a desired vinyl equivalent weight by selecting appropriate
monomers or co-monomers and appropriate degrees of
polymerization.
[0026] Functional, Non-Fluorinated, Silicone Polymer. Generally,
the functional, non-fluorinated, silicone polymer is an
organopolysiloxane polymer comprising at least two crosslinkable
reactive groups, e.g., two ethylenically-unsaturated organic
groups. In some embodiments, the functional, non-fluorinated,
silicone polymer comprises two terminal crosslinkable groups, e.g.,
two terminal ethylenically-unsaturated groups. In some embodiments,
the functional, non-fluorinated, silicone polymer comprises pendant
functional groups, e.g., pendant ethylenically-unsaturated organic
groups. In some embodiments, the functional, non-fluorinated,
silicone polymer has a vinyl equivalent weight of no greater than
20,000 grams per equivalent, e.g., no greater than 15,000, or even
no greater than 10,000 grams per equivalent. In some embodiments,
the functional non-fluorinated silicone polymer has a vinyl
equivalent weight of at least 250 grams per equivalent, e.g., at
least 500, or even at least 1000 grams per equivalent. In some
embodiments, the silicone polymer has a vinyl equivalent weight of
500 to 5000 grams per equivalent, e.g., 750 to 4000 grams per
equivalent, or even 1000 to 3000 grams per equivalent.
[0027] Exemplary functional, non-fluorinated, silicone polymers
include those comprising a triorganosiloxy-endblocked,
polydiorganosiloxane polymer. In some embodiments, the polymer
comprises R.sub.2SiO.sub.2/2 units (i.e., "D" units) and
R.sub.3SiO.sub.1/2 units (i.e., "M" units), wherein each --R group
independently represents a saturated or ethylenically-unsaturated,
substituted or unsubstituted, hydrocarbon radical, provided that at
least two R groups contain terminal ethylenic unsaturation. In some
embodiments, the remaining R groups are saturated hydrocarbon
radicals. In some embodiments, the remaining R groups are methyl
radicals.
[0028] In some embodiments, the ethylenically-unsaturated radicals
are independently selected from the group consisting of an alkenyl
radical represented by the formula
--(CH.sub.2).sub.mCH.dbd.CH.sub.2, wherein m is 0, 1, 2, 3, or 4.
In some embodiments, m is zero, and the ethylenically-unsaturated
radical is a vinyl radical. In some embodiments, m is 4, and the
ethylenically-unsaturated radical is the 5-hexenyl radical.
[0029] In some embodiments, the ethylenically-unsaturated radicals
are independently selected from the group consisting of the vinyl
radical and higher alkenyl radicals represented by the formula
--R'(CH.sub.2).sub.xCH.dbd.CH.sub.2 wherein [0030] R' denotes
--(CH.sub.2).sub.y- or --(CH.sub.2).sub.zCH.dbd.CH--; [0031] x has
the value of 1, 2, or 3; [0032] y has the value of 0, 3, or 6; and
[0033] z has the value of 3, 4, or 5.
[0034] In some embodiments, trace amounts of non-linear siloxane
units are present, i.e., SiO.sub.4/2 units (i.e., "Q" units) and
RSiO.sub.312, units (i.e., "T" units). In some embodiments, trace
amounts of other silicon-bonded radicals, such as hydroxyl and
alkoxyl may also be present.
[0035] Exemplary functional, non-fluorinated silicone polymers
comprising an average of at least two ethylenically-unsaturated
organic groups include those having the formula
M.sup.ViD.sub.xD.sup.Vi.sub.yM.sup.Vi, wherein M represents M
units, D represents D units, the superscript "Vi" indicates the
presence of ethylenically-unsaturated functional groups on either
the M or D units, x+y is the degree of polymerization, and the
individual values for x and y satisfy the functional equivalent
weights indicated previously.
[0036] Commercially available
M.sup.ViD.sub.xD.sup.Vi.sub.yM.sup.Vi, non-fluorinated silicone
polymers include those available under the trade designations DMS-V
from Gelest Inc., e.g., DMS-V05, DMS-V21, DMS-V22, DMS-V25,
DMS-V31, and DMS-V33. Other commercially available,
non-fluorinated, silicone polymers comprising an average of at
least two ethylenically-unsaturated organic groups include SYL-OFF
2-7170 and SYL-OFF 7850 (available from Dow Corning Corporation),
VMS-T11 and SIT7900 (available from Gelest Inc.), SILMER VIN 70,
SILMER VIN 100 and SILMER VIN 200 (available from Siltech
Corporation), and
2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (available
from Aldrich).
[0037] Functional Fluorosilicone Polymer. Generally, any known
fluorosilicone polymer having at least two crosslinkable reactive
groups, e.g., two ethylenically-unsaturated organic groups, may be
used as the functional fluorosilicone polymer. In some embodiments,
the functional fluorosilicone polymer comprises two terminal
crosslinkable groups, e.g., two terminal ethylenically-unsaturated
groups. In some embodiments, the functional fluorosilicone polymer
comprises pendant functional groups, e.g., pendant
ethylenically-unsaturated organic groups.
[0038] Exemplary functional, fluorinated, silicone polymers include
those comprising a triorganosiloxy-endblocked, polydiorganosiloxane
polymer. In some embodiments, the polymer comprises
R.sub.2SiO.sub.2/2 units (i.e., "D" units) and R.sub.3SiO.sub.1/2
units (i.e., "M" units), wherein each R group independently
represents a saturated or ethylenically-unsaturated, substituted or
unsubstituted hydrocarbon radical, provided that at least two R
groups contain terminal ethylenic unsaturation. At least a portion
of the remaining R groups are fluorinated hydrocarbon radicals.
[0039] In some embodiments, the functional fluorosilicone is a
fluoroorganopolysiloxane polymer comprising a siloxane backbone and
at least one pendant fluorinated group, for example a fluoroalkyl
or a fluoroether group bonded to the siloxane backbone with a
linking group. In some embodiments, the perfluoroalkyl groups are
C1 to C6, e.g., C2 to C6 or C2 to C4 perfluoroalkyl groups, e.g.,
--C.sub.4F.sub.9. In some embodiments, the linking group is an
alkylene group comprising at least two carbon atoms, e.g.,
--C.sub.2H.sub.4--. For example, in some embodiments, the
functional fluorosilicone polymer comprises a siloxane backbone and
pendant --C.sub.4F.sub.9 groups bonded to the backbone with
--C.sub.2H.sub.4-- linking groups. In some embodiments the pendant
fluorinated group is a fluoroether group. Suitable fluoroether
groups are described in the detailed description of U.S.
application Ser. No. 61/829,577 (filed 31 May 2013) and are
exemplified by OR' in the structure shown below, wherein
##STR00001## [0040] each R.sup.1 is independently an alkyl or
aryl;
[0041] R' is perfluoroalkyl of the formula:
--CF.sub.2--C.sub.qF.sub.2q--X--C.sub.rF.sub.2r--F, [0042] where q
and r are independently 0 to 4; [0043] X is a covalent bond, --O--,
or --NR.sub.f.sup.1 where R.sub.f.sup.1 is C.sub.1-C.sub.3
perfluoroalkyl;
[0044] For example, one preferred fluoroether group has the
structure
--OCH.sub.2CF(CF.sub.3)OCF.sub.2CF(CF.sub.3)OC.sub.3F.sub.7 and is
bonded to the siloxane backbone with a --CH.sub.2CH.sub.2CH.sub.2--
linking group.
[0045] In some embodiments, the ethylenically-unsaturated radicals
are independently selected from the group consisting of an alkenyl
radical represented by the formula
--(CH.sub.2).sub.mCH.dbd.CH.sub.2, wherein m is 0, 1, 2, 3, or 4.
In some embodiments, m is zero, and the ethylenically-unsaturated
radical is a vinyl radical. In some embodiments, m is 4, and the
ethylenically-unsaturated radical is the 5-hexenyl radical.
[0046] In some embodiments, the ethylenically-unsaturated radicals
are independently selected from the group consisting of the vinyl
radical and higher alkenyl radicals represented by the formula
--R'(CH.sub.2).sub.xCH.dbd.CH.sub.2 wherein [0047] R' denotes
--(CH.sub.2).sub.y- or --(CH.sub.2).sub.zCH.dbd.CH--; [0048] x has
the value of 1, 2, or 3; [0049] y has the value of 0, 3, or 6; and
[0050] z has the value of 3, 4, or 5.
[0051] Exemplary functional, fluorinated silicone polymers
comprising an average of at least two ethylenically-unsaturated
organic groups include those having the formula
M.sup.ViD.sub.xD.sup.Rf.sub.yD.sup.Vi.sub.zM.sup.Vi, wherein M
represents M units, D represents D units, D.sup.Rf represents
fluorinated D units, the superscript "Vi" indicates the presence of
ethylenically-unsaturated functional groups on either the D or M
units, the sum of x+y+z is the total degree of polymerization, and
the individual values for x and y and z satisfy the functional
equivalent weights indicated previously. The value of y is at least
1; preferably, y is at least 10 percent of the sum of x+y+z.
[0052] In some embodiments, trace amounts of non-linear siloxane
units are present, i.e., SiO.sub.4/2 units (i.e., "Q" units) and
RSiO.sub.3/2, units (i.e., "T" units). In some embodiments, trace
amounts of other silicon-bonded radicals, such as hydroxyl and
alkoxyl may also be present.
[0053] In some embodiments, the functional fluorosilicone polymer
has a vinyl equivalent weight of no greater than 50,000 grams per
equivalent, e.g., no greater than 30,000, or even no greater than
25,000 grams per equivalent. In some embodiments, the functional
fluorosilicone polymer has a vinyl equivalent weight of at least
500 grams per equivalent, for example 1,000 grams per equivalent,
e.g., at least 2,000, or even at least 3,000 grams per equivalent.
In some embodiments, the functional fluorosilicone polymer has a
vinyl equivalent weight of 500 to 40,000 grams per equivalent, for
example 1000 to 20,000 grams per equivalent, e.g. 1500 to 10,000
grams per equivalent, e.g., 2000 to 8000 grams per equivalent, or
even 3000 to 7000 grams per equivalent.
[0054] In addition, the present inventors discovered that the ratio
of the vinyl equivalent weight of the functional fluorosilicone
polymer over the vinyl equivalent weight of the functional
non-fluorinated silicone polymer can be used to control the release
force. In particular, lower release forces can be obtained as this
ratio is increased. In some embodiments, the ratio of the vinyl
equivalent weight of the functional fluorosilicone polymer over the
vinyl equivalent weight of the functional non-fluorinated silicone
polymer is at least 1, e.g., at least 2, at least 2.5 or even at
least 3. In some embodiments, the ratio is from 2 to 20, for
example from 2 to 15, from 2 to 10, from 2 to 5, from 2.5 to 5.5,
or from 3 to 5. Any one of the above-mentioned ranges can be
employed for any embodiment described herein, and can be combined
with any other embodiment or aspect of the present description.
[0055] A number of useful, commercially available, functional
fluorosilicone polymers are available from Dow Corning Corp.
(Midland, Mich.) under the SYL-OFF series of trade designations
including, e.g., SYL-OFF Q2-7785 and SYL-OFF 7786. Other functional
fluorosilicone polymers are commercially available from Momentive
(Columbus, Ohio), Shin-Etsu Chemical Company (Japan) and Wacker
Chemie (Germany). Additional functional fluorosilicone polymers are
described as component (e) at column 5, line 67 through column 7,
line 27 of U.S. Pat. No. 5,082,706 (Tangney).
[0056] Crosslinking Agents. Both the functional fluorosilicone
polymers and the functional, non-fluorinated, silicone polymers are
particularly useful in forming release coating compositions when
combined with a suitable crosslinking agent. Suitable crosslinking
agents are generally known.
[0057] Exemplary crosslinking agents include organohydrogensiloxane
crosslinking agents, i.e, siloxane polymers containing
silicon-bonded hydride groups. Suitable hydride-functional,
silicone crosslinking agents include those available under the
trade designations SYL-OFF 7488, SYL-OFF 7048 and SYL-OFF 7678 from
Dow Corning Corp. Suitable hydride-functional, fluorosilicone
crosslinking agents include those available under the trade
designations SYL-OFF Q2-7560 and SL-7561 from Dow Corning Corp.
Other useful crosslinking agents are disclosed in U.S. Pat. Nos.
5,082,706 (Tangney) and 5,578,381 (Hamada et al.).
[0058] Nonfunctional Fluorosilicone Polymer. As used herein,
nonfunctional fluorosilicone polymer refers to fluorosilicone
polymers that have neither ethylenically-unsaturated groups nor
Si--H groups, or groups that react with either of these. In some
embodiments, the nonfunctional fluorosilicone polymer may include
certain reactive groups such as epoxy and alkoxy groups, as such
groups do not readily react with either ethylenically-unsaturated
groups or Si--H groups. The nonfunctional flurosilicone polymer can
have any suitable molecular weight. Typical number average
molecular weights are from 250 to 250,000 daltons, e.g. 1,000 to
200,000 daltons, e.g. 5,000 to 175,000 daltons, e.g., or from
10,000 to 150,000 daltons. Any one of the above-mentioned ranges
can be employed for any embodiment described herein, and can be
combined with any other embodiment or aspect of the present
description.
[0059] In some embodiments, nonfunctional fluorosilicone polymers
may be prepared from functional fluorosilicones by converting all
or substantially all of the functional groups into nonfunctional
groups. As used herein, the term "capping" refers to the process of
converting, e.g., through reaction, functional groups into
nonfunctional groups. In some embodiments,
ethylenically-unsaturated groups can be capped by reacting them
with monohydride functional compounds such as
pentamethyldisiloxane.
[0060] Exemplary nonfunctional, fluorinated silicone polymers
include those having the formula MD.sub.xD.sup.Rf.sub.yM, wherein M
represents M units, D represents D units, D.sup.Rf represents
fluorinated D units, and the sum of x+y is the degree of
polymerization. The value of y is at least 1; preferably, y is at
least 10 percent of the sum of x+y. In some embodiments, trace
amounts of non-linear siloxane units are present, i.e., SiO.sub.4/2
units (i.e., "Q" units) and RSiO.sub.3/2, units (i.e., "T"
units).
[0061] In some embodiments, the nonfunctional fluorosilicone is a
fluoroorganopolysiloxane polymer comprising a siloxane backbone and
one or more pendant fluorinated groups, for example a fluoroalkyl
or a fluoroether group bonded to the siloxane backbone with a
linking group. In some embodiments, the perfluoroalkyl groups are
C1 to C6, e.g., C2 to C6 or C2 to C4 perfluoroalkyl groups, e.g.,
--C.sub.4F.sub.9. In some embodiments, the linking group is an
alkylene group comprising at least two carbon atoms, e.g.,
--C.sub.2H.sub.4--. For example, in some embodiments, the
nonfunctional fluorosilicone polymer comprises a siloxane backbone
and pendant --C.sub.4F.sub.9 groups bonded to the backbone with
--C.sub.2H.sub.4-- linking groups. In some embodiments the pendant
fluorinated group is a fluoroether group. Suitable fluoroether
groups are described in the detailed description of U.S.
application Ser. No. 61/829,577 (filed 31 May 2013) and are
exemplified by OR' in the structure discussed above. These groups
can be used with any embodiment or combination of embodiments
disclosed herein.
[0062] In some embodiments, the nonfunctional, fluorinated silicone
polymers include those having the formula
M.sup.cD.sub.xD.sup.Rf.sub.yD.sup.c.sub.zM.sup.c, wherein M
represents M units, D represents D units, D.sup.Rf represents
fluorinated D units, c indicates capping of any functional groups
present on the M or D units, and the sum of x+y+z is the degree of
polymerization. The value of y is at least 1; preferably, y is at
least 10 percent of the sum of x+y+z.
[0063] Catalysts. In some embodiments, one or more catalysts may
also be present. Suitable catalysts include, e.g., precious metal
catalysts such as platinum- and palladium-based catalysts. In some
embodiments, other catalysts may be used including, e.g., tin- and
iron-based catalysts.
[0064] The compositions of the present disclosure include: (a) a
functional, non-fluorinated, silicone polymer; (b) a functional
fluorosilicone polymer; and (c) a nonfunctional fluorosilicone
polymer. The relative amounts of the various components blended to
form release compositions will depend on a variety of factors
including, e.g., the desired release characteristics, the adhesive
to be used with the cured release composition, and the specific
selection of the functional, non-fluorinated, silicone polymer(s),
the functional fluorosilicone polymer(s), and the nonfunctional
fluorosilicone polymer(s).
[0065] In some embodiments, the composition comprises at least 50
weight percent (wt. %) of the functional, non-fluorinated, silicone
polymer based on the total weight of (a) and (b); e.g., at least 65
weight percent, or even at least 80 weight percent of the
functional, non-fluorinated, silicone polymer based on the total
weight of (a) and (b). In some embodiments, the composition
comprises no greater than 97 weight percent, e.g., no greater than
95 weight percent of the functional, non-fluorinated, silicone
polymer based on the total weight of (a) and (b). For example, in
some embodiments the composition comprises 65 to 97 weight percent,
e.g., 80 to 95 weight percent of the functional, non-fluorinated,
silicone polymer based on the total weight of (a) and (b).
[0066] In some embodiments, the composition comprises at least 3
weight percent, e.g., at least 5 weight percent, or even at least 8
weight percent of the functional, fluorosilicone polymer based on
the total weight of (a) and (b). In some embodiments, the
composition comprises no greater than 50 weight percent, e.g., 35
weight percent, e.g., no greater than 20 weight percent, or even no
greater than 15 weight percent of the functional, fluorosilicone
polymer based on the total weight of (a) and (b). For example, in
some embodiments the composition comprises 3 to 35 weight percent,
e.g., 4 to 30 weight percent, 5 to 20 weight percent, or even 8 to
15 weight percent of the functional, fluorosilicone polymer based
on the total weight of (a) and (b).
[0067] In some embodiments, the composition comprises at least 1
part by weight of the nonfunctional, fluorinated silicone polymer
per 100 parts by weight (a) and (b). In some embodiments, the
composition comprises at least 3, e.g., at least 5 parts by weight
of the nonfunctional, fluorinated silicone polymer per 100 parts by
weight of (a) and (b). In some embodiments, the composition
comprises no greater than 30, e.g., no greater than 25, or even no
greater than 15 parts by weight of the nonfunctional, fluorinated
silicone polymer per 100 parts by weight of (a) and (b). In some
embodiments, the composition comprises 3 to 30, e.g., 5 to 15 parts
by weight of the nonfunctional, fluorinated silicone polymer per
100 parts by weight of (a) and (b).
[0068] List of Illustrative Items
[0069] The following items are illustrative of various aspects of
this description, but are not intended to be limiting.
[0070] Item 1. A composition comprising a blend of: [0071] (a) a
functional, non-fluorinated, silicone polymer; [0072] (b) a
functional fluorosilicone polymer; and [0073] (c) a nonfunctional
fluorosilicone polymer.
[0074] Item 2. The composition of item 1, wherein the blend
comprises at least 50 weight percent of the functional,
non-fluorinated, silicone polymer based on the total weight of (a)
and (b).
[0075] Item 3. The composition of item 2, wherein the blend
comprises 65 to 97 weight percent, inclusive, of the functional,
non-fluorinated, silicone polymer based on the total weight of (a)
and (b).
[0076] Item 4. The composition of any one of the preceding items,
wherein the blend comprises at least 3 weight percent of the
functional fluorosilicone polymer based on the total weight of (a)
and (b).
[0077] Item 5. The composition of item 4, wherein the blend
comprises 3 to 35 weight percent of the functional fluorosilicone
polymer based on the total weight of (a) and (b).
[0078] Item 6. The composition of any one of the preceding items,
wherein the blend comprises at least 1 part by weight of the
nonfunctional fluorosilicone polymer per 100 parts by weight of (a)
and (b).
[0079] Item 7. The composition of item 6, wherein the blend
comprises no greater than 30 parts by weight of the nonfunctional
fluorosilicone polymer per 100 parts by weight of (a) and (b).
[0080] Item 8. The composition of any one of the preceding items,
wherein the functional, non-fluorinated, silicone polymer comprises
at least two ethylenically-unsaturated organic groups.
[0081] Item 9. The composition of item 8, wherein the functional,
non-fluorinated, silicone polymer has a vinyl equivalent weight of
500 to 5000 grams per equivalent.
[0082] Item 10. The composition of any one of the preceding items,
wherein the functional fluorosilicone polymer comprises at least
two ethylenically-unsaturated organic groups.
[0083] Item 11. The composition of item 10, wherein the functional
fluorosilicone polymer has a vinyl equivalent weight of 500 to
40,000 grams per equivalent.
[0084] Item 12. The composition of items 10 or 11, wherein the
ratio of the vinyl equivalent weight of the functional
fluorosilicone polymer over the vinyl equivalent weight of the
functional non-fluorinated silicone polymer is at least 1.
[0085] Item 13. The composition of item 12, wherein the ratio of
the vinyl equivalent weight of the functional fluorosilicone
polymer to the vinyl equivalent weight of the functional
non-fluorinated silicone polymer is from 2 to 20.
[0086] Item 14. The composition according to any one of the
preceding items, wherein the nonfunctional fluorosilicone polymer
comprises one or more fluorinated groups having two or more
fluorinated carbon atoms.
[0087] Item 15. The composition of item 14, wherein the fluorinated
groups of the nonfunctional fluorosilicone polymer comprise
nonafluorohexyl or fluorinated ether groups.
[0088] Item 16. The composition according to any one of the
preceding items, wherein the functional fluorosilicone polymer
comprises fluorinated groups comprising two or more fluorinated
carbon atoms.
[0089] Item 17. The composition of item 16, wherein the fluorinated
groups of the functional fluorosilicone polymer comprises
nonafluorohexyl or fluorinated ether groups.
[0090] Item 18. The composition according to any one of the
preceding items, further comprising at least one of a silicone
crosslinker and a fluorosilicone crosslinker.
[0091] Item 19. The composition according to item 18, wherein at
least one crosslinker comprises a silicon bonded hydride group.
[0092] Item 20. A cured release material comprising the composition
according to any one of the preceding items, wherein the
functional, non-fluorinated, silicone polymer and the functional
fluorosilicone polymer are crosslinked.
[0093] Item 21. The cured release material of item 20, wherein the
crosslinked functional, non-fluorinated, silicone polymer comprises
the reaction product of the functional, non-fluorinated, silicone
polymer and a silicone crosslinker.
[0094] Item 22. The cured release material of item 20 or 21,
wherein the crosslinked functional fluorosilicone polymer comprises
the reaction product of the functional fluorosilicone polymer and a
fluorosilicone crosslinker.
[0095] Item 23. A release liner comprising a substrate and the
cured release material according to any one of items 20 to 22
bonded to at least a portion of at least one surface of the
substrate.
[0096] Item 24. An adhesive article comprising the release liner of
item 23 and an adhesive in contact with the at least a portion of
at least one surface of the cured release material.
[0097] Item 25. The adhesive article of item 24, wherein the
adhesive is a silicone adhesive.
[0098] Item 26. The adhesive article of item 25, wherein the
silicone adhesive is an e-beam cured silicone adhesive.
[0099] Item 27. The adhesive article of item 25, wherein the
silicone adhesive is a silicone polyurea adhesive.
[0100] Item 28. The adhesive article of item 25, wherein the
silicone adhesive is a polydiorganosiloxane-polyoxamide
adhesive.
[0101] Item 29. A method of forming a release article comprising:
applying the composition according to any one of items 1 to 19 to
at least a portion of at least one surface of a substrate, and
crosslinking the functional, non-fluorinated, silicone polymer and
the functional fluorosilicone polymer.
[0102] Item 30. The method of item 29, wherein crosslinking the
functional, non-fluorinated, silicone polymer comprising reacting
the functional, non-fluorinated, silicone polymer with a silicone
crosslinker.
[0103] Item 31. The method of item 29 or 30, wherein crosslinking
the functional fluorosilicone polymer comprising reacting the
functional fluorosilicone polymer with a fluorosilicone
crosslinker.
[0104] Item 32. The method according to any one of items 29 to 31,
wherein applying the composition comprises applying the composition
in a solvent and the method further comprises removing solvent.
[0105] Item 33. A method of forming an adhesive article comprising:
applying an adhesive to the release material of any one of items 20
to 23.
[0106] Item 34. The method of item 33, wherein applying the
adhesive comprises laminating a cured adhesive to the release
material.
[0107] Item 35. The method of item 33, wherein applying the
adhesive comprises applying an uncured adhesive to the release
material and curing the adhesive.
[0108] Item 36. A composition comprising a blend of: [0109] (a) at
least 80 to no greater than 95 weight percent based on the total
weight of (a) and (b) of a functional, non-fluorinated, silicone
polymer comprising at least two ethylenically-unsaturated groups;
[0110] (b) at least 5 to no greater than 20 weight percent based on
the total weight of (a) and (b) of a functional fluorosilicone
polymer comprising at least two ethylenically-unsaturated groups;
and [0111] (c) at least 1 to no greater than 15 parts by weight of
a nonfunctional fluorosilicone polymer based on 100 parts by weight
of (a) and (b).
[0112] Item 37. The composition of item 36, wherein the functional,
non-fluorinated, silicone polymer has a vinyl equivalent weight of
500 to 5000 grams per equivalent; the functional fluorosilicone
polymer has a vinyl equivalent weight of 500 to 40,000 grams per
equivalent; and the ratio of the vinyl equivalent weight of the
functional fluorosilicone polymer over the vinyl equivalent weight
of the functional non-fluorinated silicone polymer is at least
between 2 and 6, inclusive.
[0113] Item 38. The composition of item 36 or 37, wherein the
nonfunctional fluorosilicone polymer comprises fluorinated groups
comprising two or more fluorinated carbon atoms; and the functional
fluorosilicone polymer comprises fluorinated groups comprising two
or more fluorinated carbon atoms.
[0114] Item 39. A cured release material comprising the composition
according to any one of the items 36 to 38, wherein the functional,
non-fluorinated, silicone polymer and the functional fluorosilicone
polymer are crosslinked.
[0115] Item 40. The cured release material of item 39, wherein the
crosslinked functional, non-fluorinated, silicone polymer comprises
the reaction product of the functional, non-fluorinated, silicone
polymer and a silicone crosslinker; and wherein the crosslinked
functional fluorosilicone polymer comprises the reaction product of
the functional fluorosilicone polymer and a fluorosilicone
crosslinker.
[0116] Item 41. A release liner comprising a substrate and the
cured release material according to item 40 bonded to at least a
portion of at least one surface of the substrate.
[0117] Item 42. An adhesive article comprising the release liner of
item 41 and a silicone adhesive in contact with at least a portion
of at least one surface of the cured release material.
EXAMPLES
[0118] Functional Non-Fluorinated Silicone Polymers: Fn-XF-SP.
[0119] Functional, non-fluorinated silicone polymer Fn-XF-SP-A was
prepared as follows. A polyethylene bottle was charged with 750.0 g
(2.529 mol) of octamethylcyclotetrasiloxane (D.sub.4, Gelest), 51.0
g (0.273 mol) of 1,3-divinyltetramethyldisiloxane
(M.sup.Vi-M.sup.Vi, Gelest), 4.0 g of activated carbon and 0.8 g of
concentrated sulfuric acid. The resultant mixture was shaken at
room temperature for 36 hours. The mixture was filtered, and the
filtrate was stripped of volatile material using a wiped film
evaporator operating at a pressure of 20 Pa (0.15 Torr) and a
jacket temperature of 175.degree. C., providing 635.0 g of the
product, Fn-XF-SP-A, a clear, colorless liquid. The .sup.1H and
.sup.29Si NMR spectra for Fn-XF-SP-A were consistent with the
desired structure.
TABLE-US-00001 TABLE 1A Summary of functional, non-fluorinated,
silicone polymers. Eq. Wt. Trade I.D. Functionality (g/mole) name
Source Fn-XF-SP-A Vinyl 1400 Preparation described herein
Fn-XF-SP-B Vinyl 2000 VIN 70 Siltech Fn-XF-SP-D Vinyl 3000 V21
Gelest Fn-XF-SP-E Vinyl 4700 V22 Gelest Functional Fluorosilicone
Polymers: Fn-FSP.
[0120] Functional Fluorosilicone Polymers: Fn-FSP.
TABLE-US-00002 TABLE 1B Summary of functional, fluorosilicone
polymers. Eq. Wt. Fluorinated Trade I.D. Functionality (g/mole)
groups name Source Fn-FSP-A Vinyl 2600 Trifluoro- FSR 2000
Momentive propyl Fn-FSP-B Vinyl 5100 Trifluoro- 7555 Dow propyl
Corning Fn-FSP-C Vinyl 5500 Nonafluoro- 7786 Dow hexyl Corning
Fn-FSP-D Vinyl (*) .sub. 17,000 (#) Nonafluoro- Q2-7785 Dow hexyl
Corning Fn-FSP-E Vinyl (*) .sub. 30,000 (##) (###) X-70-201S
Shin-Etsu (*) Fn-FSP-B and Fn-FSP-E include both terminal and
pendant functional groups. (#) Calculated vinyl equivalent weight
excluding 2-3 percent 1,3-divinyltetramethyldisiloxane contained in
the commercial product. Also excludes solvent present in polymer as
purchased. (##) Calculated vinyl equivalent weight excluding
solvent present in polymer as purchased. (###)
--CH.sub.2CH.sub.2CH.sub.2--OCH.sub.2CF(CF.sub.3)OCF.sub.2CF(CF.sub.-
3)OC.sub.3F.sub.7 Nonfunctional Fluorosilicone Polymers:
NFn-FSP.
[0121] Nonfunctional Fluorosilicone Polymers: NFn-FSP.
[0122] Nonfunctional, fluorosilicone polymers were prepared by
capping vinyl-functional polyorganosiloxane polymers. In
particular, the vinyl functional groups were capped by reaction
with pentamethyldisiloxane, a monohydride functional capping
agent.
[0123] Nonfunctional, fluorosilicone polymer NFn-FSP-A. To 100.00 g
of Dow Corning SYL-OFF 7786 (vinyl-functional fluorosilicone
polymer formulated with a platinum hydrosilylation catalyst, 100
weight percent solids, approximately 16.6 mmol of vinyl
functionality) were added 50 mL of heptane, 50 mL of ethyl acetate
and 7.37 g (49.7 mmol) of pentamethyldisiloxane (Gelest). The
resulting mixture was heated at 60.degree. C. for 6 hours. Solvent
and excess pentamethyldisiloxane were separated under reduced
pressure to provide 102.40 g of the product, NFn-FSP-A, a viscous,
amber liquid. The .sup.1H and .sup.29Si NMR spectra for NFn-FSP-A
indicated complete consumption of starting vinyl functionality and
were consistent with the structure of the desired product.
[0124] Nonfunctional, fluorosilicone polymer NFn-FSP-B. A
nonfunctional fluorosilicone polymer having
--C.sub.3H.sub.6OC.sub.4F.sub.9 pendant groups was prepared
according to Example 4 of U.S. application Ser. No. 61/829,577
("Fluoroalkyl Silicones", Qiu and Rathore, filed 31 May 2013).
[0125] Nonfunctional, fluorosilicone polymer NFn-FSP-F. To 50.00 g
of Momentive FF160 (vinyl-functional fluorosilicone polymer, 100
weight percent solids, approximately 2.0 mmol of vinyl
functionality) were added 50 mL of heptane and 1.48 g (10.0 mmol)
of pentamethyldisiloxane (Gelest). The resulting mixture was heated
to 60.degree. C., and 50 mg of a 2.1-2.4 weight percent solution of
platinum(0) in xylene (Gelest) were added. The reaction mixture was
maintained at 60.degree. C. overnight. Solvent and excess of
pentamethyldisiloxane were separated under reduced pressure to
provide 50.30 g of the product, NFn-FSP-F, a viscous, light amber
liquid. The .sup.1H and .sup.29Si NMR spectra for NFn-FSP-F
indicated complete consumption of starting vinyl functionality and
were consistent with the structure of the desired product.
[0126] Nonfunctional, fluorosilicone polymer NFn-FSP-G. To 110.11 g
of Dow Corning Syl-Off Q2-7785 (vinyl-functional fluorosilicone
polymer formulated with a platinum hydrosilylation catalyst, 88
weight percent solids in heptane, 96.9 g of polymer, approximately
32.3 mmol of vinyl functionality) were added an additional 100 mL
of heptane and 13.10 g (88.3 mmol) of pentamethyldisiloxane
(Gelest), and the resulting mixture was heated at 60.degree. C.
overnight. Solvent and excess of pentamethyldisiloxane were
separated under reduced pressure to provide 100.45 g of a viscous,
light amber fluid. To this was added 25.11 g of heptane to provide
an 80 weight percent solids solution of the product, NFn-FSP-G. The
.sup.1H and .sup.29Si NMR spectra indicated complete consumption of
starting vinyl functionality and were consistent with the structure
of the desired product.
TABLE-US-00003 TABLE 1C Summary of nonfunctional, fluorosilicone
polymers. MW Fluorinated Trade I.D. (g/mole) groups name Source
NFn-FSP-A 11,000 Nonafluoro- Preparation described hexyl herein
NFn-FSP-B 13,300 --C.sub.3H.sub.6--O--C.sub.4F.sub.9 U.S.
application Ser. No. 61/829,577 (Ex. 4) NFn-FSP-C 14,000 Trifluoro-
FMS-141 Dow propyl Corning NFn-FSP-F 51,000 Trifluoro- Preparation
described propyl herein NFn-FSP-G 137,000 Nonafluoro- Preparation
described hexyl herein
TABLE-US-00004 TABLE 1D Summary of crosslinkers. Eq. Wt. Trade
Class I.D. Function (g/mole) name Source Silicone SXL-1 hydride 76
7488 Dow Crosslinker Corning SXL-2 hydride 97 7678 Dow Corning
Fluorosilicone FXL-1 hydride 166 SL 7561 Dow Crosslinker Corning
FXL-2 hydride 224 Q2 7560 Dow Corning
[0127] Unless noted in the Examples and Comparative Examples
described below, release coatings were prepared using the follow
general methods. Formulated release solutions were made by mixing
functional silicone polymers (non-fluorinated and/or fluorinated)
with the appropriate amount of hydride functional crosslinker in
20:80 heptane:ethyl acetate. For formulations containing more than
one functional polymer, the appropriate crosslinker was added in
the amounts needed for each functional component. Table 1E lists
which crosslinkers and the hydride to vinyl ratio used for each
functional silicone polymer.
TABLE-US-00005 TABLE 1E Crosslinkers and hydride to vinyl ratios
used for each functional polymer. Functional Polymer ID Crosslinker
Hydride to Vinyl Ratio Fn-XF-SP-A SXL-2 1.20 Fn-XF-SP-B SXL-2 1.20
Fn-XF-SP-C SXL-1 1.20 Fn-XF-SP-D SXL-2 1.32 Fn-XF-SP-E SXL-2 1.55
Fn-FSP-A SXL-1 1.5 Fn-FSP-B FXL-1 1.6 Fn-FSP-C FXL-2 2.0 Fn-FSP-D
FXL-2 .sup. 2.92 (#) (#) Hydride to vinyl excluding 2-3 percent
1,3-divinyltetramethyldisiloxane contained in the commercial
product.
[0128] Fn-FSP-E, which is sold as a mixture of crosslinker and
fluorosilicone, was used as received from the manufacturer.
[0129] All of the functional silicone polymers listed in Table 1E
already contained platinum hydrosilylation catalyst and inhibitor
except Fn-XF-SP-B, Fn-FSP-A and Fn-FSP-E which were missing one or
both of these. 120 ppm of Pt catalyst
(platinum-divinyltetramethyldisiloxane complex in xylene from
Gelest) and 0.2 weight percent inhibitor (diallyl maleate available
from Momentive) were added to Fn-XF-SP-B. 0.2 weight percent
inhibitor (diallyl maleate available from Momentive) was added to
Fn-FSP-A. 0.5 parts of CAT-50-P1 (Pt catalyst in solvent from
Shin-Etsu) was added to 100 parts of Fn-FSP-E as recommended by the
manufacturer.
[0130] Some solutions had additional nonfunctional polymers added
to them, reported as part per hundred (pph) by weight based on 100
parts by weight of the functional polymers.
[0131] Rod Coating. Formulated release solutions were made at 15
weight percent solids in 20:80 heptane:ethyl acetate. These
solutions were then coated on to Hostaphan 3SAB polyester backing
(primed polyester available from Mitsubishi Polyester Film, Inc)
using a #5 Mayer rod (wire wound rod available from RDS, Inc.) and
thermally cured in an oven at 120.degree. C. for five minutes.
[0132] Gravure Coating. Alternatively some release coatings were
made by gravure coating 7 or 11 weight percent solids solutions in
20:80 heptane:ethyl acetate on to Hostaphan 3SAB polyester film
with a 60 pyramidal roll. Gravure coated samples were cured in-line
at 120.degree. C. for approximately 45 seconds (oven length of 11.3
meters, line speed of 15.2 meters/minute).
[0133] Prepared release liners were aged for a minimum of one week
at 23.degree. C. and 50 percent relative humidity before any tests
were conducted. Unless otherwise noted, release test samples were
prepared by laminating (using a 15 cm wide soft rubber roller and
light pressure) the release liners to various cured, silicone
adhesives. The resulting samples were aged at either 50.degree. C.
or 70.degree. C. for predetermined amounts of time such as 3 days,
14 days, 28 days, 56 days and 112 days. All samples were then
re-equilibrated at 23.degree. C. and 50 percent relative humidity
for at least one day prior to testing.
[0134] After aging and re-equilibration, a 2.54 or 1.6 centimeter
wide and approximately 20 centimeter long sample of the test sample
was cut using a specimen razor cutter. The cut sample was applied
lengthwise onto the platen surface of a peel adhesion tester (an
IMASS SP-2100 tester, obtained from IMASS, Inc., Accord, Mass.)
using 3M Double Coated Paper Tape 410M (available from 3M Company,
St. Paul, Minn., USA). The release liner was peeled from the
adhesive at an angle of 180 degrees at, e.g., 30.5 cm/minute.
[0135] Readhesion samples were prepared by applying the adhesive
strip exposed by the release test to either a clean stainless steel
plate or a clean glass plate using two back and forth passes (four
passes total) with a with a 4.4 cm wide two kilogram rubber roller.
Readhesions for ADH-1, ADH-2, and ADH-3 were all measured using a
stainless steel plate, while readhesions for ADH-4, ADH-5 and ADH-6
all used glass as the substrate. Regardless of the substrate used,
readhesion was measured without dwell time by measuring the force
required to peel the adhesive from the plate at an angle of 180
degrees at, e.g., 30.5 cm/minute.
[0136] For some samples, release and readhesion were tested at
speeds greater than 30.5 cm/minute as noted in the results
presented below. For speeds greater than 762 cm/minute, an IMASS
ZPE-1100W tester (obtained from IMASS, Inc., Accord, Mass.) and
samples approximately 40 cm in length were used.
[0137] Electron beam cured silicone adhesives (ADH-1, ADH-2). ADH-1
was prepared according to Example 24 described in U.S. Pat. No.
8,541,481, except the adhesive was coated onto a rayon-rich
nonwoven fabric with a 12 micron polyester elastomer film. The
adhesive thickness was 100 microns (4 mils). ADH-2 was prepared in
the same manner except ADH-2 contained 38 weight percent MQ
tackifier with the remainder being silanol functional PDMS
fluid.
[0138] Commercial silicone adhesive tapes (ADH-3, ADH-4). ADH-3 is
commercially available from 3M Company as 3M Kind Removal Silicone
Tape 2775-1. ADH-3 is a soft silicone adhesive designed to stick to
skin and is similar to ADH-1 and ADH-2. ADH-4 is commercially
available from 3M Company as 3M Polyester Tape 8403 Green tapes.
ADH-4 is a peroxide-cured silicone adhesive that is stiffer
adhesive than ADH-3.
[0139] Thermal dried silicone adhesives (ADH-5, ADH-6). ADH-5 is a
tackified, polydiorganosiloxane-polyurea block copolymer silicone
adhesive and was prepared according to Example 28 described in U.S.
Pat. No. 7,078,093. ADH-6 is a tackified,
polydiorganosiloxane-polyoxamide block copolymer silicone. ADH-6
was prepared by making an elastomer with the composition of Example
12 in WO 2011/082069 and blending it with 100 parts on a dry basis
of SR545 MQ resin purchased from Momentive. Solvent was added to
give overall solids of 35 weight percent in a solvent mixture of
ethyl acetate/IPA/toluene 63/19/18. Both ADH-5 and ADH-6 were
coated on to Hostaphan 3 SAB so as to produce dry thickness of 51
mils after thermal drying (described in ADH-5 preparation).
[0140] Control-1 was a commercially available release liner used
with silicone PSAs available as SCOTCHPAK 9741 release liner from
3M Company. The liner consists of perfluorinated polymer coated
polyester substrate. In some embodiments, release values comparable
to the performance of Control-1 may be desirable, as this liner
provides lower release forces (i.e., premium) with some silicone
adhesives, and is commercially acceptable for many
applications.
[0141] CE-1 was a commercially available release liner used with
silicone PSAs available as M117 release liner from Siliconature
LLC. The liner is believed to consist of a fluorosilicone polymer
having trifluoropropyl groups coated on a polyester substrate. This
liner is generally known to provide higher release forces than
Control-1 against a variety of silicone adhesives.
[0142] Examples EX-1 and EX-2. Examples were prepared by combining
(X) a functional, non-fluorinated, silicone polymer, (Y) a
functional, fluorosilicone polymer, and (Z) a nonfunctional,
fluorosilicone polymer to form release coatings, as summarized in
Table 2. All samples were coated on the 3SAB backing using a #5
Mayer rod.
TABLE-US-00006 TABLE 2 Compositions of Examples EX-1 and EX-2. (X)
(Z) Fn-XF- (Y) NFn- I.D. SP Fn-FSP FSP Composition Coating solution
EX-1 B C G 90:10 X:Y + 15 wt. % in EX-2 B C A 12 pph Z 20:80
Hept:EthAc
[0143] Samples were prepared with the Control-1, CE-1, EX-1 and
EX-2 materials using adhesive ADH-1 (e-beam cured silicone
adhesive). Release and readhesion tests were performed according to
the general method for release/readhesion testing described above.
A stainless steel plate was used when measuring the readhesion
values. As shown in Table 3, the blended release compositions
provided premium (i.e., lower) release force comparable to that
obtained with the high-cost, perfluorinated release material of
Control-1, with no loss of readhesion that might be expected when
incorporating nonfunctional materials into a release
composition.
TABLE-US-00007 TABLE 3 Results using ebeam-cured silicone adhesives
with the liners of Table 2. 3 days at 50.degree. C. 14 days at
50.degree. C. Release Readhesion Release Readhesion I.D. (g/25 mm)
(g/25 mm) (g/25 mm) (g/25 mm) Control-1 43 204 39 206 EX-1 21 199
19 195 EX-2 15 213 31 207 CE-1 85 211 100 214
[0144] As shown in Table 3, blended release compositions of the
present disclosure provided significantly lower release forces than
those obtained with CE-1, a conventional fluorosilicone release
material. The release performance of one exemplary release material
according to some embodiments of the present disclosure was
compared to a variety of other common fluorosilicone release
materials over a range of peel speeds.
[0145] The blend of EX-1 (90:10 parts by weight Fn-XF-SP-B:
Fn-FSP-C with 12 pph NFn-FSP-G) was gravure coated from 11 weight
percent solids on to Hostaphan 3SAB polyester film and cured
in-line to yield a dry coat weight of about 1.0 gram per square
meter. Common fluorosilicone release materials were coated from
various solvents and solvent blends on Hostaphan 3SAB polyester
film using a #5 Mayer rod and cured to produce dry coat weights of
about 1.0 grams per square meter. The resulting samples were
laminated to adhesive ADH-3 and aged for 14 days at 50.degree. C.
The premium release characteristics of the blended compositions of
the present disclosure are apparent from the results summarized in
Table 4.
TABLE-US-00008 TABLE 4 Release and readhesion compared to
commercial fluorosilicone release materials. Release (gm/25 mm)
30.5 229 762 1524 3048 Compo- cm/ cm/ cm/ cm/ cm/ Readhesion ID.
sition min min min min min (gm/25 mm) EX-1 Blend* 6 30 137 215 336
434 CE-2 Fn-FSP-A 61 217 N/T 428 589 364 CE-3 Fn-FSP-B 62 236 384
468 614 348 CE-4 Fn-FSP-C 43 193 356 468 593 407 CE-5 Fn-FSP-D 87
263 460 580 724 371 *90:10 Fn-XF-SP-B:Fn-FSP-C + 12 pph NFn-FSP-G
N/T = not tested.
[0146] The performance of exemplary blended release compositions of
the present disclosure was compared to similar systems containing
only one or two of the three components present in the blended
release compositions of the present disclosure. The compositions of
these comparative examples are summarized in Table 5A.
TABLE-US-00009 TABLE 5A Release compositions comparing one- and
two- part systems to three-part compositions. (X) (Z) Fn-XF- (Y)
NFn- I.D. SP Fn-FSP FSP Composition Coating solution CE-6 -- C --
100 X 11.2 wt. % in CE-7 -- C G 100 Y + HFE 7500 12 pph Z CE-8 B C
-- 90:10 X:Y 15 wt. % in EX-1 B C G 90:10 X:Y + 20:80 Hept:EthAc
EX-2 B C A 12 pph Z
[0147] Release coatings were prepared to produce dry coat weights
of about 1.0 grams per square meter. Adhesive ADH-1 was laminated
to the release coatings. The release and readhesion forces are
summarized in Table 5B. The compositions and results for three
component systems of Examples EX-1 and EX-2 are included for
comparison.
TABLE-US-00010 TABLE 5B Release and readhesion results using
adhesive ADH-1. 3 days at 50.degree. C. 14 days at 50.degree. C.
Release Readhesion Release Readhesion I.D. (g/25 mm) (g/25 mm)
(g/25 mm) (g/25 mm) CE-6 67 212 75 225 CE-7 23 223 21 220 CE-8 105
222 123 260 EX-1 21 199 19 195 EX-2 15 213 31 207
[0148] Both low speed and high speed peel of a liner from an
adhesive can be important. High speed peel tests were conducted
using select liners from Table 2. The results are summarized in
Table 6. As shown, although CE-7 had release values comparable to
those obtained with EX-1 and EX-2 at low speeds, at high speeds,
the release value of CE-7 was about twice as high as the exemplary
release materials of the present disclosure.
TABLE-US-00011 TABLE 6 High speed peel test results. Release (g/25
mm) I.D. 30.5 cm/min 229 cm/min 762 cm/min EX-1 19 58 140 EX-2 31
78 120 CE-7 21 81 250
[0149] In some applications it may be desirable to tailor the
release force to meet certain objectives. In some embodiments,
various attributes of one or more of the three required components
of the blended release materials of the present disclosure may be
adjusted to modify the resulting release characteristics; often
without adversely affecting the readhesion properties.
[0150] The release materials of EX-1 and EX-2 were prepared using
nonfunctional, fluorosilicone polymers with nonafluorohexyl
fluorinated groups. Samples prepared with other nonfunctional
polymers are summarized in Table 7A. Release and readhesion results
are summarized in Table 7B, along with the results obtained with
EX-1 and EX-2, repeated from Table 3 for comparison.
[0151] All samples were prepared as a 90:10 blend of X:Y with 12
pph Z. The coatings were prepared as a 15 weight percent solids
solutions in a 20:80 blend of heptane and ethyl acetate. Examples
EX-3 and EX-4 were prepared with nonfunctional, fluorosilicone
polymers having trifluoropropyl fluorinated groups (NFn-FSP-C and
NFn-FSP-F, respectively). CE-9 was prepared using a nonfunctional,
non-fluorinated silicone polymer (DMS-T35 silicone polymer
available from Gelest, MW of 49,400 g/mole).
TABLE-US-00012 TABLE 7A Compositions of Examples EX-1 and EX-2, and
various comparative examples. (X) (Z) Fn-XF- (Y) NFn- I.D. SP
Fn-FSP FSP Composition Coating solution EX-3 B C C 90:10 X:Y + 15
wt. % in EX-4 B C F 12 pph Z 20:80 Hept:EthAc CE-9 B C * *
Nonfunctional, non-fluorinated, silicone polymer (DMS-T35 silicone
from Gelest).
[0152] As shown in Table 7B, the use of nonfunctional
fluoropolymers having fluorinated groups containing more than one
fluorinated carbon, e.g., nonafluorohexyl groups, resulted in lower
release forces. In comparison, similar compositions using
nonfunctional fluoropolymers having fluorinated groups containing
only one fluorinated carbon, e.g., trifluoropropyl groups,
exhibited much higher release forces, comparable to the use of a
non-fluorinated, nonfunctional silicone polymer. Thus, one could
use the number of fluorinated carbons to tailor the release force
of compositions of the present disclosure. In some embodiments,
depending on the adhesive and the release force desired, it may be
desirable to use nonfunctional fluorosilicones having fluorinated
groups having at least two fluorinated carbons, for example, at
least four fluorinated carbon atoms.
TABLE-US-00013 TABLE 7B Release and readhesion results. Fluorinated
3 days at 50.degree. C. 14 days at 50.degree. C. groups of the
Release Readhesion Release Readhesion I.D. NFn-FSP (g/25 mm) (g/25
mm) (g/25 mm) (g/25 mm) EX-1 Nonafluoro- 21 199 19 195 hexyl EX-2
Nonafluoro- 15 213 31 207 hexyl EX-3 Trifluoro- 99 216 126 215
propyl EX-4 Trifluoro- 80 214 103 213 propyl CE-9 None 87 208 119
208 (silicone)
[0153] As summarized in Table 8A, release compositions were
prepared with similar compositions, but with functional,
non-fluorinated silicone polymers with different equivalent
weights. All samples were prepared as a 90:10 weight ratio of X:Y
with 8 pph Z. The compositions were prepared as a 7 weight percent
solids solutions in 20:80 blend of heptane:ethyl acetate. Dry
release coatings were produced by gravure coating these solutions
onto Hostaphan 3SAB and thermally curing them in line to yield a
dry release coat weight of about 0.7 grams per square meter.
TABLE-US-00014 TABLE 8A Release compositions with varying
equivalent weight silicone polymers. (X) (Z) Fn-XF- (X) (Y) NFn-
I.D. SP Eq. Wt. Fn-FSP FSP EX-5 A 1400 C G EX-6 D 3000 C G EX-7 E
4700 C G
[0154] ADH-2 was laminated to the release coatings. Test results
are presented in Table 8B. Results obtained with the liner of
Control-1 are shown for comparison. Generally, as the vinyl
equivalent weight is increased, the crosslink density will
decrease. As shown in Table 8B, in some embodiments, the vinyl
equivalent weight can be used to adjust the release force without
affecting readhesion, as the release force also increases with the
increase in vinyl equivalent weight.
TABLE-US-00015 TABLE 8B Impact of vinyl equivalent weight of the
functional silicone on release and readhesion. 3 days at 50.degree.
C. 14 days at 50.degree. C. Release Readhesion Release Readhesion
I.D. (g/25 mm) (g/25 mm) (g/25 mm) (g/25 mm) Control-1 82 288 50
216 EX-5 26 249 15 269 EX-6 55 229 41 257 EX-7 88 257 112 260
[0155] In some embodiments, release force can also be adjusted by
varying the amount of nonfunctional, fluorosilicone polymer. As
summarized in Table 9A, release compositions were prepared as a
90:10 weight ratio of X:Y with varying amounts of Z, the
nonfunctional, fluorosilicone polymer.
TABLE-US-00016 TABLE 9A Release compositions with varying amounts
of nonfunctional, fluorosilicone polymer I.D. (X) Fn-XF-SP (Y)
Fn-FSP (Z) NFn-FSP (Z) pph CE-10 B C -- 0 EX-8 B C G 1 EX-9 B C G 2
EX-10 B C G 4 EX-11 B C G 12
[0156] ADH-3 was laminated to the prepared release coatings. The
samples were then aged for 28 days at 50.degree. C. Release and
readhesion were tested at low speed and high speed. The results,
summarized in Table 9B, illustrate the ability to use the amount of
the nonfunctional, fluorosilicone polymer to adjust the release
performance with no adverse impact on readhesion.
TABLE-US-00017 TABLE 9B Release and readhesion variation with the
amount of nonfunctional fluorosilicone. 30.5 cm/min 229 cm/min
Release Readhesion Release Readhesion I.D. pph Z (g/25 mm) (g/25
mm) (g/25 mm) (g/25 mm) CE-10 0 91 148 222 331 EX-8 1 35 133 95 323
EX-9 2 19 138 57 334 EX-10 4 4 154 67 335 EX-11 12 6 140 22 321
[0157] The release performance of various blended release
compositions were evaluated with a variety of standard and
aggressive silicone adhesives. The release compositions summarized
in Table 10A were gravure coated on to Hostaphan 3SAB polyester
film and cured in line. The dry coat weight of EX-13 was slightly
below target at about 0.85 gram per square meter. ADH-4 was
laminated to the prepared release coatings. The resulting samples
were aged for 14 days at 70.degree. C.
TABLE-US-00018 TABLE 10A Release compositions. (X) (Y) (Z) I.D.
Fn-XF-SP Fn-FSP NFn-FSP Composition Coating solution EX-12 B C G
95:5 X:Y + 11 wt. % in 4 pph Z 20:80 Heptane:Ethyl Acetate EX-13 A
C G 90:10 X:Y + 9 wt. % in 4 pph Z 20:80 Heptane:Ethyl Acetate
EX-14 B C G 90:10 X:Y + 11 wt. % in 12 pph Z 20:80 Heptane:Ethyl
Acetate
[0158] As summarized in Table 10B, various blended release
compositions of the present disclosure provided premium release
performance with this peroxide-cure, silicone adhesive. Although
further reductions in release force can be achieved by increasing
the amount of component (Z), the nonfunctional fluorinated silicone
polymer, EX-14 illustrates that readhesion results may be adversely
affected.
TABLE-US-00019 TABLE 10B Release and readhesion results with a
peroxide-cured, silicone adhesive. 30.5 cm/min 229 cm/min Release
Readhesion Release Readhesion I.D. (g/25 mm) (g/25 mm) (g/25 mm)
(g/25 mm) EX-12 18 509 25 894 EX-13 5 704 5 1038 EX-14 3 359 4
568
[0159] The release compositions summarized in Table 11A were tested
using a silicone polyurea adhesive, ADH-5. In this test, CE-11 was
coated significantly thicker than 1.0 gram per square meter in
order to achieve premium performance.
TABLE-US-00020 TABLE 11A Release compositions. (X) (Y) (Z) I.D.
Fn-XF-SP Fn-FSP NFn-FSP Composition Coating solution CE-11 -- C --
100 Y 21 wt. % in HFE7500 gravure coated CE-12 A C -- 90:10 X:Y 15
wt. % in EX-15 A C G 90:10 X:Y + 20:80 Heptane:Ethyl Acetate 12 pph
Z coated with #5 Mayer rod EX-16 B C G 90:10 X:Y + 12 pph Z
[0160] As summarized in Table 11B, premium release performance was
obtained with various blended release compositions of the present
disclosure, even with this aggressive silicone adhesive. In
addition, in contrast to single- and dual- component release
formulations exemplified by Comparative Examples CE-11 and CE-12,
the release force obtained when using the three-component
compositions of the present disclosure was not adversely affected
by extended aging.
TABLE-US-00021 TABLE 11B Release results with a silicone polurea
adhesive. Release at 152 cm/min (g/25 mm) 7 days 14 days 28 days 56
days 112 days I.D. at 50.degree. C. at 50.degree. C. at 50.degree.
C. at 50.degree. C. at 50.degree. C. CE-11 28 39 57 96 121 CE-12 72
103 180 279 304 EX-15 5 6 5 5 6 EX-16 9 11 10 9 11
[0161] The same release compositions summarized in Table 11A were
also tested using a silicone polyoxamide block copolymer based
adhesive, ADH-6. Like the ADH-5 silicone polyurea adhesive, ADH-6
is an aggressive silicone adhesive. As summarized in Table 11C,
various blended release compositions of the present disclosure
provided premium release performance with this aggressive silicone
adhesive. In addition, in contrast to the comparative release
formulations, the release force was not adversely affected by
extended aging.
TABLE-US-00022 TABLE 11C Release results with a silicone
polyoxamide block copolymer based adhesive. Release at 152 cm/min
(g/25 mm) 7 days 14 days 28 days 56 days 112 days I.D. at
50.degree. C. at 50.degree. C. at 50.degree. C. at 50.degree. C. at
50.degree. C. CE-11 38 55 74 76 168 CE-12 241 277 359 411 458 EX-15
4 5 4 7 9 EX-16 8 9 10 19 24
[0162] One deficiency with some prior art release coatings is the
inability to coat and cure adhesives directly on the release
material. In such cases, the adhesives are often coated on a
separate process liner, cured, and then transferred to the desired
release material. Such a process requires additional steps and
costs. In addition, in some applications it may be desirable to
bond adhesives to porous substrates such as foams. In such
embodiments, it may be difficult or impossible to coat the adhesive
directly on the substrate, and coating the adhesive on the release
material may be more practical or efficient.
[0163] The release materials summarized in Table 12A were prepared,
coated, and cured. Adhesive ADH-1 was coated directly on the
release materials and then e-beam cured. The same general procedure
described for making ADH-1 was followed to make these samples
except that the adhesive was coated on the release liner instead of
the backing. After e-beam curing the backing was laminated to the
adhesive coated release liner to make the test samples. The release
and readhesion results are summarized in Table 12B. As shown,
superior release and readhesion results were obtained with the
blended release compositions of the present disclosure, even when
compared to a commercial, premium release liner.
TABLE-US-00023 TABLE 12A Release compositions. (X) (Y) (Z) I.D.
Fn-XF-SP Fn-FSP NFn-FSP Composition Coating solution Control-1 --
W9741 -- Commercial, premium release liner CE-13 B C -- 90:10 X:Y
15 wt. % in EX-17 B C G 90:10 X:Y + 20:80 Heptane:Ethyl 12 pph Z
Acetate EX-18 B C A 90:10 X:Y + coated with #5 Mayer rod 12 pph
Z
TABLE-US-00024 TABLE 12B Release and readhesion with direct
adhesive coating. 3 days at 50.degree. C. 14 days at 50.degree. C.
Release Readhesion Release Readhesion I.D. (g/25 mm) (g/25 mm)
(g/25 mm) (g/25 mm) Control-1 430 106 406 73 CE-13 150 139 154 120
EX-17 75 138 78 112 EX-18 16 142 35 113
[0164] As shown in Tables 7A and 7B, some compositions using a
nonfunctional fluorosilicone having fluorinated groups containing
only one fluorinated carbon (i.e., trifluoropropyl groups) did not
perform as well as compositions using a nonfunctional
fluorosilicone having fluorinated groups containing two or more
fluorinated carbons (e.g., nonafluorohexyl groups). The release
compositions of Table 13A were prepared using a functional
fluorosilicone with trifluoropropyl groups (i.e., Fn-FSP-B) with a
variety of trifluoropropyl and nonafluorohexyl group-containing
nonfunctional fluorosilicones.
TABLE-US-00025 TABLE 13A Release compositions using a functional
fluorosilicone with trifluoropropyl groups. (Z) (X) (Y) (Z)
fluorinated I.D. Fn-XF-SP Fn-FSP NFn-FSP groups Composition CE-14 B
B -- none 70:30 X:Y EX-19 A B G nonafluorohexyl 90:10 X:Y + 8 pph Z
EX-20 A B G nonafluorohexyl 80:20 X:Y + 8 pph Z EX-21 B B G
nonafluorohexyl 70:30 X:Y + 12 pph Z EX-22 B B A nonafluorohexyl
70:30 X:Y + 12 pph Z EX-23 B B F trifluoropropyl 70:30 X:Y + 12 pph
Z EX-24 B B C trifluoropropyl 70:30 X:Y + 12 pph Z
[0165] As summarized in Table 13B, premium release could be
obtained using a functional fluorosilicone polymer with
trifluoropropyl groups through appropriate modifications in the
compositions. However, in this example, higher levels of the
functional fluorosilicone were required to achieve premium release.
As before, the use of a nonfunctional fluorosilicone with only one
fluorinated carbon atom did not produce premium release, while the
use of nonfunctional fluorosilicones with two or more fluorinated
carbon atoms (e.g., nonafluorohexyl groups) yielded premium release
in similar compositions. Thus, in some embodiments, it may be
desirable to use functional, fluorosilicone polymers having
fluorinated groups containing at least two fluorinated carbon
atoms, e.g., at least four fluorinated carbon atoms.
TABLE-US-00026 TABLE 13B Release and readhesion results 3 days 14
days at 50.degree. C. at 50.degree. C. Release Release Readhesion
I.D. (g/25 mm) (g/25 mm) (g/25 mm) CE-14 566 793 461 EX-19 N/T 685
395 EX-20 N/T 280 366 EX-21 130 301 416 EX-22 30 57 572 EX-23 645
822 493 EX-24 496 638 490
[0166] Release compositions prepared with nonfunctional
fluorosilicone polymers having at least four fully fluorinated
carbon atoms. These compositions are summarized in Table 14A.
TABLE-US-00027 TABLE 14A Release compositions. (X) (Y) (Z) (Z) I.D.
Fn-XF-SP Fn-FSP NFn-FSP fluorinated groups Composition CE-15 B C --
none 90:10 X:Y EX-25 B C G nonafluorohexyl 90:10 X:Y + 12 pph Z
EX-26 B C B C3H6-O-C4F9 90:10 X:Y + 12 pph Z
[0167] Release and readhesion results using adhesive ADH-1
laminated to the release materials are summarized in Table 14B.
Results obtained with Control-1 are included for comparison. The
data shows that incorporation of nonfunctional fluoropolymers
having fluorinated groups containing more than one fluorinated
carbon results in lower release forces.
TABLE-US-00028 TABLE 14B Release and readhesion. 3 days at
50.degree. C. 14 days at 50.degree. C. Release Readhesion Release
Readhesion I.D. (g/25 mm) (g/25 mm) (g/25 mm) (g/25 mm) Control-1
43 499 39 483 CE-15 212 530 217 529 EX-25 43 484 21 479 EX-26 22
395 21 401
[0168] Release compositions prepared from other fluorosilicone
polymers having at least four fully fluorinated carbon atoms. These
compositions are summarized in Table 15A. CE-16 and CE-27 were
prepared as 15 weight percent solutions in a 20:80 blend of heptane
and ethyl acetate, CE-17 was diluted down to a 5 weight percent
solution with FS-thinner (available from Shin Etsu) per the
manufacture's recommendations while CE-18 and EX-26 were diluted
down to 8 weight percent solid solutions in a 20:80 blend of
heptane and ethyl acetate to improve solubility.
TABLE-US-00029 TABLE 15A Release compositions. (X) (Y) (Z) (Z) I.D.
Fn-XF-SP Fn-FSP NFn-FSP fluorinated groups Composition CE-16 B C --
none 90:10 X:Y CE-17 E none 100 Y CE-18 B E -- none 90:10 X:Y EX-27
B C G nonafluorohexyl 90:10 X:Y + 12 pph Z EX-28 B E G
nonafluorohexyl 90:10 X:Y + 12 pph Z
[0169] Release and readhesion results using adhesive ADH-2
laminated to the release materials are summarized in Table 15B.
Results obtained with Control-1 are included for comparison. As
before, incorporation of functional fluoropolymers having
fluorinated groups containing more than one fluorinated carbon
results in lower release forces. Also, three-part compositions
provided lower release forces than one- and two-part systems.
TABLE-US-00030 TABLE 15B Release and readhesion. Release and
readhesion at 30.5 cm/min (g/25 mm) 3 days at 50.degree. C. 14 days
at 50.degree. C. Release Readhesion Release Readhesion I.D. (g/25
mm) (g/25 mm) (g/25 mm) (g/25 mm) Control-1 51 177 40 188 CE-16 141
135 163 115 CE-17 41 149 38 177 CE-18 125 125 151 163 EX-27 45 143
51 154 EX-28 16 135 20 156
[0170] As demonstrated by the examples above and as illustrated in
FIG. 1, the blended release compositions of the present disclosure
may be used as the release layer of a release liner. Referring to
FIG. 1, release liner 10 comprises substrate 20 and release layer
30, bonded to first major surface 21 of substrate 20. In some
embodiments, the release layer is directly bonded to the substrate.
In some embodiments, the release layer may be indirectly bonded to
the substrate, e.g., one or more intervening layers (e.g., primer
layers) may be interposed between the release layer and the
substrate. Generally, any substrate may be used including, e.g.,
paper, glassine, polymeric films, polycoated papers, and the
like.
[0171] The release compositions of the present disclosure may also
be suitable for use in a wide variety of adhesive articles. For
example, in some embodiments, a supported or unsupported adhesive
layer may be in contact with the release layer. The release layer
may be bonded to a substrate (i.e., the release composition may be
the release layer on a release liner). In some embodiments, the
adhesive may be bonded, directly or indirectly, to a backing.
[0172] The adhesive can be a silicone adhesive. Exemplary silicone
adhesives include e-beam cured silicone adhesives, such as those
described in U.S. Pat. No. 8,541,181 (Bresnick), as well as
silicone polyurea adhesives, such as those described in U.S. Pat.
No. 7,078,093 (Sheridan), and polydiorganosiloxane-polyoxamide
adhesives such as those described in WO 2011/082069 (Hays).
[0173] For example, referring to FIG. 2, exemplary adhesive article
100 according to some embodiments of the present disclosure
comprises backing 150. Generally, any known backing may be used
including those comprising one or more layers of paper, polymer
films, metallic foils, foam, and the like. First major surface 141
of adhesive 140 is bonded to backing 150. Opposite second major
surface 142 or adhesive 140 is in contact with the release layer
130, which itself is bonded to substrate 120. In the foregoing
description, a layer may be bonded directly or indirectly to its
adjacent layer(s).
[0174] In some embodiments, the adhesive article may not include a
release liner. For example, in some embodiments, the release
material may be bonded to one major surface of a backing with the
adhesive bonded to the opposite major surface. The adhesive may
then be self-wound or stacked such that the adhesive of one layer
contacts the release material of the underlying layer. In some
embodiments, the adhesive article may not include a backing
associated with the adhesive. For example, in some embodiments,
such as transfer tapes, an adhesive may be in contact with the one
release liner or between two release liners.
[0175] Various modifications and alterations of this invention will
become apparent to those skilled in the art without departing from
the scope and spirit of this invention.
* * * * *