U.S. patent application number 16/837174 was filed with the patent office on 2020-09-17 for sheet, moisture-proof method of adherend using the sheet and corrosion-proof method of metal plate using the sheet.
This patent application is currently assigned to Nitto Denko Corporation. The applicant listed for this patent is Nitto Denko Corporation, NITTO, INC.. Invention is credited to Yu-chu CHEN, Shinji HOSHINO, Derek JORGENSEN, Masatoshi SUZUKI.
Application Number | 20200290312 16/837174 |
Document ID | / |
Family ID | 1000004866840 |
Filed Date | 2020-09-17 |
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United States Patent
Application |
20200290312 |
Kind Code |
A1 |
JORGENSEN; Derek ; et
al. |
September 17, 2020 |
SHEET, MOISTURE-PROOF METHOD OF ADHEREND USING THE SHEET AND
CORROSION-PROOF METHOD OF METAL PLATE USING THE SHEET
Abstract
The present invention provides a sheet having an elastomer layer
having a Shore A hardness of less than 40, wherein the elastomer
layer has an adhesion force to stainless steel of not more than 11
oz/in at 90 degree peel strength.
Inventors: |
JORGENSEN; Derek; (Lakewood,
NJ) ; HOSHINO; Shinji; (Osaka, JP) ; CHEN;
Yu-chu; (Lakewood, NJ) ; SUZUKI; Masatoshi;
(Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nitto Denko Corporation
NITTO, INC. |
Osaka
Lakewood |
NJ |
JP
US |
|
|
Assignee: |
Nitto Denko Corporation
Osaka
NJ
NITTO, INC.
Lakewood
|
Family ID: |
1000004866840 |
Appl. No.: |
16/837174 |
Filed: |
April 1, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15563761 |
Oct 2, 2017 |
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PCT/US16/26361 |
Apr 7, 2016 |
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16837174 |
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62144536 |
Apr 8, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B32B 27/32 20130101;
B32B 2605/08 20130101; B32B 2419/04 20130101; B32B 27/34 20130101;
B32B 7/14 20130101; B32B 2605/18 20130101; B32B 15/18 20130101;
C09J 7/22 20180101; C09J 7/30 20180101; C09J 2483/00 20130101; B32B
5/02 20130101; C09J 2475/00 20130101; B32B 25/10 20130101; B32B
27/08 20130101; C09J 171/02 20130101; C09J 2471/00 20130101; B64C
1/18 20130101; B32B 2307/54 20130101; C09J 2203/314 20130101; B32B
7/12 20130101; B32B 2307/5825 20130101; B32B 27/322 20130101; B32B
2307/714 20130101; B32B 2262/0276 20130101; B32B 7/02 20130101;
B32B 25/20 20130101; C09J 2301/1242 20200801; B32B 7/10 20130101;
B32B 15/08 20130101; B32B 15/06 20130101; B32B 2307/732 20130101;
B32B 2607/00 20130101; B32B 2405/00 20130101; B32B 2419/00
20130101; C09J 2301/312 20200801; B32B 2307/748 20130101; B32B
2307/536 20130101; B32B 27/12 20130101; B32B 25/06 20130101; B32B
7/06 20130101; B32B 7/00 20130101; B32B 25/08 20130101; B32B
2274/00 20130101; B32B 27/36 20130101; B32B 2605/00 20130101; C09J
2427/006 20130101; B32B 15/20 20130101; B32B 27/10 20130101; B32B
2255/26 20130101; B32B 27/304 20130101; B32B 2262/101 20130101;
B32B 2307/7265 20130101; B32B 2307/50 20130101; B32B 2471/00
20130101 |
International
Class: |
B32B 7/10 20060101
B32B007/10; B32B 7/14 20060101 B32B007/14; C09J 171/02 20060101
C09J171/02; B32B 15/06 20060101 B32B015/06; B32B 15/08 20060101
B32B015/08; B32B 15/20 20060101 B32B015/20; B32B 25/06 20060101
B32B025/06; B32B 25/08 20060101 B32B025/08; B32B 25/10 20060101
B32B025/10; B32B 27/12 20060101 B32B027/12; B32B 27/30 20060101
B32B027/30; B32B 27/32 20060101 B32B027/32; B32B 27/34 20060101
B32B027/34; B32B 27/36 20060101 B32B027/36; B32B 7/06 20060101
B32B007/06; B32B 7/12 20060101 B32B007/12; B32B 7/00 20060101
B32B007/00; B32B 7/02 20060101 B32B007/02; B32B 5/02 20060101
B32B005/02; B32B 25/20 20060101 B32B025/20; B32B 15/18 20060101
B32B015/18; B32B 27/10 20060101 B32B027/10; B32B 27/08 20060101
B32B027/08; C09J 7/30 20060101 C09J007/30; C09J 7/22 20060101
C09J007/22 |
Claims
1. A sheet comprising an elastomer layer having a Shore A hardness
of less than 40, wherein the elastomer layer has an adhesion force
to stainless steel of not more than 11 oz/in at 90 degree peel
strength, and the sheet has a moisture absorption percentage of not
more than 2.5% as measured according to ASTM D570.
2. The sheet according to claim 1, comprising, in the following
order, the elastomer layer, and further comprising a core material
layer and a pressure-sensitive adhesive layer.
3. The sheet according to claim 2, further comprising a release
liner laminated on the elastomer layer.
4. The sheet according to claim 2, further comprising a release
liner laminated on the pressure-sensitive adhesive layer.
5. The sheet according to claim 2, wherein the core material layer
is a plastic film.
6. The sheet according to claim 2, wherein the core material layer
is a nonporous film.
7. The sheet according to claim 2, wherein the core material layer
is a fluororesin film.
8. The sheet according to claim 1, comprising the elastomer layer,
and further comprising a core material layer and a second elastomer
layer having a Shore A hardness of less than 40.
9. The sheet according to claim 8, further comprising a release
liner laminated on one of the elastomer layer and the second
elastomer layer.
10. The sheet according to claim 8, further comprising a substrate
laminated on one of the elastomer layer and the second elastomer
layer.
11. The sheet according to claim 8, wherein the core material layer
is a plastic film.
12. The sheet according to claim 8, wherein the core material layer
is a nonporous film.
13. The sheet according to claim 8, wherein the core material layer
is a fluororesin film.
14. The sheet according to claim 1, wherein the elastomer layer is
a silicone rubber layer or urethane rubber layer having a Shore A
hardness of less than 40.
15. The sheet according to claim 2, wherein the pressure-sensitive
adhesive layer is a polyoxyalkylene-based adhesive layer.
16. A method of moisture-proofing an adherend, comprising adhering
the sheet according to claim 1 to the adherend with the elastomer
layer of the sheet as an adhesive surface to the adherend.
17. The method according to claim 16, wherein the adherend is at
least one adherend selected from the group consisting of a floor
panel and a constructional material in a transporter or
structure.
18. The method according to claim 16, further comprising, after the
adhering, peeling the sheet from the adherend and performing the
method using the peeled sheet or using a newly prepared sheet
according to claim 1.
19. A method of corrosion-proofing a metal plate, comprising
adhering the sheet according to claim 1 to the metal plate with the
elastomer layer of the sheet as an adhesive surface to the metal
plate.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a novel sheet
simultaneously having superior adhesiveness to an adherend and
superior re-peel property.
BACKGROUND OF THE INVENTION
[0002] For example, carpets of various materials and forms are
generally laid on the floor panel of aircrafts for the purpose of
walking ease, beauty, heat-retaining property and the like. On the
other hand, since electrical components, electric wiring and the
like are set under the floor panel, it is necessary to shut off the
moisture and humidity from the floor panel so that the moisture
will not penetrate under the floor panel. The airframe
constructional material under a floor panel (hereinafter to be also
simply abbreviated as "constructional material") cannot be easily
exchanged during maintenance, and corrosion needs to be prevented
even when moisture penetrates under the floor panel. Particularly,
since floor panel and airframe constructional material of aircraft
cargo room are more frequently exposed to moisture than those of
the cabin, the anticorrosion property of the airframe
constructional material of aircraft cargo room poses a more
important problem. However, since the floor panel is fixed onto the
body frame by bolting, it is difficult to completely prevent
moisture permeation from the clearance between a bolt and a screw
hole formed for bolting a floor panel, even when the bolt is
screwed into the screw hole. For this reason, an adhesive tape with
high moisture-proof property is adhered to a floor panel and a
carpet is laid thereon to shut off the floor panel from water and
humidity. As an adhesive tape with high moisture-proof property,
for example, an adhesive tape using a polyether-based polyurethane
is known (US2004/0070156 A1).
SUMMARY OF THE INVENTION
[0003] As the basic property of an adhesive tape used for the
aforementioned application, superior adhesion to adherends is
necessary to isolate floor panel and airframe constructional
material as adherends from water and humidity (hereinafter
"isolation from water and humidity" is also simply referred to as
"moisture-proof") and to prevent corrosion thereof. Although not
clearly indicated in US2004/0070156 A1, for efficiency of the
maintenance work of a floor panel, or a floor panel and a
constructional material, and reuse of a floor panel after
maintenance, an adhesive tape requires easy removability that
permits easy re-peeling from an adherend (floor panel,
constructional material etc.), and absence of development of an
adhesive residue on peeling. Also, in an adhering work of an
adhesive tape to a floor panel, a constructional material etc., it
is not always easy to adhere an adhesive tape in a uniform manner
to desired part of a floor panel (or constructional material)
without enclosing air between the tape and the floor panel (or
constructional material), and re-adhering (once peeling and
adhering again) is often performed. From the aspects of suppression
of property decrease (degradation) of the adhesive tape due to
re-adhering of the tape, efficiency of adhesion work of an adhesive
tape (including re-adhesion) and the like, and easy removability is
particularly important.
[0004] In view of the above-mentioned situation, the present
invention aims to provide a novel sheet simultaneously having
superior adhesion to an adherend and superior re-peel property.
[0005] Generally, as a narrow "sheet" is called a "tape", the
"sheet" in the present invention also encompasses a "tape"
according to usual practice.
[0006] The present inventors have conducted intensive studies and
found that a sheet wherein at least one of the surface layers is
constituted of an elastomer layer having a Shore A hardness of less
than 40, and the elastomer layer has an adhesion force to stainless
steel of not more than 11 oz/in at 90 degree peel strength can
solve the above-mentioned problems, which resulted in the
completion of the present invention.
[0007] Therefore, the present invention provides the following.
[0008] [1] A sheet having an elastomer layer having a Shore A
hardness of less than 40, wherein the elastomer layer has an
adhesion force to stainless steel of not more than 11 oz/in at 90
degree peel strength. [0009] [2] The sheet of the above-mentioned
[1], having a laminate constitution of elastomer layer having a
Shore A hardness of less than 40/core material/pressure-sensitive
adhesive layer. [0010] [3] The sheet of the above-mentioned [2],
which is a double-faced adhesive sheet wherein a release liner is
further laminated on the elastomer layer having a Shore A hardness
of less than 40. [0011] [4] The sheet of the above-mentioned [2],
which is a double-faced adhesive sheet wherein a release liner is
further laminated on the pressure-sensitive adhesive layer. [0012]
[5] The sheet of the above-mentioned [2], wherein the core material
is a plastic film. [0013] [6] The sheet of the above-mentioned [2],
wherein the core material is a nonporous film. [0014] [7] The sheet
of the above-mentioned [2], wherein the core material is a
fluororesin film. [0015] [8] The sheet of the above-mentioned [1],
having a laminate 35 constitution of elastomer layer having a Shore
A hardness of less than 40/core material/elastomer layer having a
Shore A hardness of less than 40. [0016] [9] The sheet of the
above-mentioned [8], which is a double-faced adhesive sheet wherein
a release liner is further laminated on one of the elastomer layers
having a Shore A hardness of less than 40. [0017] [10] The sheet of
the above-mentioned [8], which is a single-faced adhesive sheet
wherein a substrate is further laminated on one of the elastomer
layers having a Shore A hardness of less than 40. [0018] [11] The
sheet of the above-mentioned [8], wherein the core material is a
plastic film. [0019] [12] The sheet of the above-mentioned [8],
wherein the core material is a nonporous film. [0020] [13] The
sheet of the above-mentioned [8], wherein the core material is a
fluororesin film. [0021] [14] The sheet of the above-mentioned [1],
wherein the elastomer layer having a Shore A hardness of less than
40 is a silicone rubber layer or urethane rubber layer having a
Shore A hardness of less than 40. [0022] [15] The sheet of the
above-mentioned [2], wherein the pressure-sensitive adhesive layer
is a polyoxyalkylene-based adhesive layer. [0023] [16] A
moisture-proof method of an adherend, comprising adhering the sheet
of the above-mentioned [1] to the adherend, with the elastomer
layer having a Shore A hardness of less than 40 of the sheet as an
adhesive surface to the adherend. [0024] [17] The method of the
above-mentioned [16], wherein the adherend is a floor panel and/or
a constructional material in a transporter or structure. [0025]
[18] The method of the above-mentioned [16], comprising, after said
method, peeling the sheet from the adherend, performing said method
using the peeled sheet, or using a newly prepared sheet of the
above-mentioned [1]. [0026] [19] A corrosion-proof method of a
metal plate, comprising adhering the sheet of the above-mentioned
[1] to the metal plate, with the elastomer layer having a Shore A
hardness of less than 40 of the sheet as an adhesive surface to the
metal plate.
[0027] According to the sheet of the present invention, by
adhering, to an adherend, the sheet with the elastomer layer having
a Shore A hardness of less than 40 of the sheet as an adhesive
surface to the adherend, the adherend can be placed in a superior
close adhesion state to be isolated from humidity and water
(including salt water). Therefore, an adherend in need of
moisture-proof such as a floor panel of a transporter such as
aircraft, boats and ships and the like, structure and the like, and
a constructional material under a floor panel of an aircraft and
the like can be isolated from humidity and water (including salt
water) for a long term by adhering the sheet of the present
invention to the adherend. In addition, since an adherend can be
isolated from humidity and water (including salt water) for a long
term, corrosion and discoloration of such sealed object can be
prevented at a high level.
[0028] In addition, the sheet adhered to the adherend can be easily
peeled off from the adherend. Therefore, a decrease (degradation)
in the property of the sheet due to the peeling of the sheet can be
suppressed, and the sheet can be reused. Since re-adhesion (once
peeling and adhering again) in adhering work of a sheet can be
performed rapidly, adhesion work of an adhesive tape (including
re-doing of adhesion) can be performed efficiently.
[0029] When the sheet of the present invention is a sheet of an
embodiment including a laminate constitution of elastomer layer
having a Shore A hardness of less than 40/core
material/pressure-sensitive adhesive layer, for example,
moisture-proof of a floor panel and an airframe constructional
material can be achieved, and a floor panel and an airframe
constructional material can be temporarily fixed (permanently fixed
by fastening screw after temporary fixing) by adhering the surface
of an elastomer layer having a Shore A hardness of less than 40 to
the floor panel, and adhering the surface of the pressure-sensitive
adhesive layer to the airframe constructional material.
Particularly, in the case of a sheet wherein a release liner is
laminated on an elastomer layer having a Shore A hardness of less
than 40, a pressure-sensitive adhesive layer having the release
liner is adhered to the floor panel, and the release liner is
peeled off, the floor panel is placed on and pressed against an
airframe constructional material with the elastomer layer having a
Shore A hardness of less than 40 being opposed to the airframe
constructional material, whereby the floor panel and airframe
constructional material become moisture-proof and the floor panel
can be simultaneously laid on the airframe constructional material.
Therefore, a floor panel laying work can be performed efficiency. A
technique including adhering a pressure-sensitive adhesive layer to
an airframe constructional material in advance and mounting a floor
panel on an elastomer layer is also possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1(A) is a schematic view of a roll shape of the sheet
in the first form of the present invention, and FIG. 1(B) is a
partly-enlarged sectional view of the sheet shown in FIG. 1(A).
[0031] FIG. 2(A) is a schematic view of a roll shape of the sheet
in the first form of the present invention, and FIG. 2(B) is a
partly-enlarged sectional view of the sheet shown in FIG. 2(A).
[0032] FIG. 3(A) is a schematic view of a roll shape of the sheet
in the second form of the present invention, and FIG. 3(B) is a
partly-enlarged sectional view of the sheet shown in FIG. 3(A).
[0033] FIG. 4(A) is a schematic view of a roll shape of the sheet
in the third form of the present invention, and FIG. 4(B) is a
partly-enlarged sectional view of the sheet shown in FIG. 4(A).
[0034] FIG. 5(A) is a schematic view of a roll shape of the sheet
in the fourth form of the present invention, and FIG. 5(B) is a
partly-enlarged sectional view of the sheet shown in FIG. 5(A).
[0035] FIG. 6(A) is a schematic view of a roll shape of the sheet
in the fifth form of the present invention, and FIG. 6(B) is a
partly-enlarged sectional view of the sheet shown in FIG. 6(A).
[0036] In the Figures, 1 is an elastomer layer having a Shore A
hardness of less than 40, 2 is a core material, 3 is a
pressure-sensitive adhesive layer, 4 is a release liner, 5 is a
substrate, 10-15 are sheets, and 51-56 are rolls.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The present invention is explained in the following by
referring to preferable embodiments.
[0038] The sheet of the present invention is mainly characterized
in that it has an elastomer layer having a Shore A hardness of less
than 40, and the adhesion force of the elastomer layer to stainless
steel is not more than 11 oz/in at 90 degree peel strength.
[0039] That is, the present invention has found that a sheet
constituted to have an elastomer layer having a Shore A hardness of
less than 40, wherein the elastomer layer having a Shore A hardness
of less than 40 has an adhesion force to stainless steel of not
more than 11 oz/in at 90 degree peel strength, can be a sheet
showing superior adhesion to an adherend and superior re-peel
property from the adherend, by adhering the sheet to the adherend,
with the elastomer layer having a Shore A hardness of less than 40
as an adhesive surface to the adherend.
[0040] In the sheet of the present invention, the Shore A hardness
of the elastomer layer is measured according to ASTM D2240.
[0041] That is, an elastomer press cured in a size of 6 in.times.6
in.times.0.07 at 177.degree. C. for 5 min is used as a sample,
ASKER Durometer Type A is pressed on the surface of the sample, and
the value is taken as Shore A hardness.
[0042] The 90 degree peel strength which is an adhesion force to
stainless steel of the elastomer layer is measured according to
ASTM D1000.
[0043] That is, a sample (a sheet cut into 1 inch width) is adhered
to a SUS304 polished plate manufactured by Chemsultants
International at room temperature by one reciprocation press with a
2 kgf roller and, after leaving for 30 min at room temperature from
the adhesion, and the peel strength is measured at peel angle
90.degree., peel rate 2 in/min.
[0044] The surface of the polished plate is washed with gauze
containing toluene, toluene is dried at room temperature and plate
is adhered to a sample.
[0045] FIG. 1(B), FIG. 2(B) show sheet 10 in the first form. Sheet
10 has a laminate constitution of elastomer layer 1 having a Shore
A hardness of less than 40/core material 2/pressure-sensitive
adhesive layer 3. Sheet 10 in the first form before use, that is,
before adhering sheet 10 to an adherend, is generally roll 51
wherein an elastomer layer 1 having a Shore A hardness of less than
40 further laminated with a release liner 4 (FIG. 1(B)) is rolled
up (FIG. 1(A)), or roll 52 wherein a pressure-sensitive adhesive
layer 3 further laminated with a release liner 4 is laminated (FIG.
2(B)) is rolled up (FIG. 2(A)).
[0046] FIG. 3(B) shows sheet 11 in the second form. Sheet 11 is a
laminate having a laminate constitution of elastomer layer 1 having
a Shore A hardness of less than 40/core material 2/elastomer layer
1 having a Shore A hardness of less than 40. Sheet 11 in the second
form before use, that is, before adhering sheet 11 to an adherend,
is generally roll 53 wherein one of the elastomer layers 1 having a
Shore A hardness of less than 40 further laminated with a release
liner 4 (FIG. 3(B)) is rolled up.
[0047] FIG. 4(B) shows sheet 12 in the third form. Sheet 12 is a
single layer sheet having only an elastomer layer 1 having a Shore
A hardness of less than 40. Sheet 12 in the third form before use,
that is, before adhering sheet 12 to an adherend, is generally roll
54 wherein an elastomer layer 1 having a Shore A hardness of less
than 40 further laminated with a release liner 4 (FIG. 4(B)) is
rolled up.
[0048] Sheets 10-12 in the first-the third forms are what is called
"double-faced adhesive sheets" wherein the double faces of the
sheet become adhesive surfaces to an adherend. The sheet of the
present invention also includes what is called a "single-faced
adhesive sheet" wherein only single face of the sheet is an
adhesive surface to an adherend. As such single-faced adhesive
sheet, sheets in the following form can be mentioned.
[0049] FIG. 5(B) shows sheet 13 in the fourth form. Sheet 13 has a
laminate constitution of elastomer layer 1 having a Shore A
hardness of less than 40/core material 2/elastomer layer 1 having a
Shore A hardness of less than 40/substrate 5. Sheet 13 in the
fourth form before use, that is, before adhering sheet 13 to an
adherend, is roll 55 which is rolled up with substrate 5 on the
outside face (FIG. 5(A)).
[0050] FIG. 6(B) shows sheet 14 in the fifth form. Sheet 14 has a
laminate constitution of elastomer layer 1 having a Shore A
hardness of less than 40/substrate 5. Sheet 14 in the fifth form
before use, that is, before adhering sheet 14 to an adherend, is
roll 56 which is rolled up with substrate 5 on the outside face
(FIG. 6(A)).
[0051] The sheet of the present invention is used by adhering an
elastomer layer having a Shore A hardness of less than 40 to an
adherend that should certain become moisture-proof. An elastomer
layer having a Shore A hardness of less than 40 is adhered to an
adherend to place same in a superior close adhesion state capable
of isolating the adherend from humidity and water (including salt
water). Therefore, an adherend in need of moisture-proof such as a
floor panel of a transporter such as aircraft, boats and ships and
the like, structure and the like, and a constructional material
under a floor panel of an aircraft and the like can be isolated
from humidity and water (including salt water) for a long term by
adhering the sheet of the present invention to the adherend. In
addition, since an adherend can be isolated from humidity and water
(including salt water) for a long term, corrosion and discoloration
of such sealed object can be prevented at a high level. When the
elastomer layer has a Shore A hardness of not less than 40, the
sheet cannot be adherend in a superior close adhesion state capable
of isolating the adherend from humidity and water (including salt
water).
[0052] While an adherend can be isolated from humidity and water
(including salt water) by adhering a pressure-sensitive adhesive
layer of a sheet, which affords a high adhesion force, to the
adherend, the sheet cannot be easily peeled off from the
adherend.
[0053] In the sheet of the present invention, the Shore A hardness
of the elastomer layer having a Shore A hardness of less than 40 is
preferably not more than 39 and, to impart initial adhesiveness
(tackiness), it is more preferably not more than 30. While the
lower limit of the Shore A hardness is not particularly limited,
not less than 0.5 is preferable, and not less than 1 is more
preferable.
[0054] The sheet of the present invention is a sheet having an
elastomer layer having a Shore A hardness of less than 40 and an
adhesion force to stainless steel of not more than 11 oz/in at 90
degree peel strength. Since the adhesion force of the elastomer
layer to stainless steel is not more than 11 oz/in at 90 degree
peel strength, the sheet adhered to an adherend with the surface of
the elastomer layer having a Shore A hardness of less than 40 as an
adhesive surface to the adherend adheres to the adherend in a good
close adhesion state to the adherend and can be easily peeled when
detached. When the 90 degree peel strength exceeds 11 oz/in, even
when the sheet is adhered to an adherend with the surface of an
elastomer layer having a Shore A hardness of less than 40 as an
adhesive surface to the adherend, the sheet cannot be easily peeled
off from the adherend.
[0055] In the sheet of the present invention, the 90 degree peel
strength of an elastomer layer having a Shore A hardness of less
than 40 to stainless steel is preferably not more than 5 oz/in,
more preferably not more than 3 oz/in. The 90 degree peel strength
is preferably not less than 1 oz/in. When the 90 degree peel
strength is not less than 1 oz/in, sufficient adhesiveness can be
secured when the sheet is adhered to an adherend, and it
advantageously acts on the maintenance of moisture-proof and
anticorrosion of the adherend.
[0056] An adhesion target of pressure-sensitive adhesive layer 3 of
sheet 10 in the first form, and an adhesion target of one of two
elastomer layers 1 having a Shore A hardness of less than 40 of
sheet 11 in the second form may be an adherend that does not
necessarily require moisture-proof or anticorrosion, or an adherend
that does not necessarily require re-peeling of the adhered sheet.
However, in sheet 11 in the second form, when two elastomer layers
1 having a Shore A hardness of less than 40 are each adhered to an
adherend requiring moisture-proof or anticorrosion, moisture-proof
and anticorrosion of two adherends can be achieved by isolating
each adherend from humidity and water (including salt water), and
the sheet can be easily peeled off from the two adherends.
[0057] The sheet 13 in the fourth form (i.e., sheet having laminate
constitution of elastomer layer 1 having a Shore A hardness of less
than 40/core material 2/elastomer layer 1 having a Shore A hardness
of less than 40/substrate 5) has higher strength (tensile strength,
tear strength etc.) due to the core material as compared to sheet
14 in the fifth form consisting only of substrate 5 and elastomer
layer 1 alone, and advantageously shows smaller water permeability
of the sheet. In addition, since a material for elastomer layer
formation is coated twice, a sheet having an elastomer layer with a
thickness (total thickness) that cannot be provided by single
coating can be advantageously obtained.
[0058] Examples of the "adherend" in the present invention include
various metal members such as aluminum, duralumin, iron, steel
(stainless steel, carbon steel (common steel), nickel-chrome steel,
nickel-chrome-molybdenum steel, chrome steel, chrome-molybdenum
steel, manganese steel etc.) and the like; various plastic members;
various glass-fiber-reinforced plastic (GFRP) members such as
glass-cloth-reinforced epoxy-impregnated aramid resin and the like;
various carbon-fiber-reinforced plastic (CFRP) members such as
carbon-fiber-reinforced epoxy-impregnated aramid resin and the
like; and the like.
[0059] Examples of the adherend to be moisture-proof include
various metal members (board, rod, pipe etc.) such as airframe
constructional material of aircraft and the like, floor panel
(material: aluminum, duralumin, stainless steel,
glass-fiber-reinforced plastics (GFRP), carbon-fiber-reinforced
plastic (CFRP) etc.) of transporters such as aircraft and the like,
structure and the like, and the like.
[0060] An adherend that does not necessarily require moisture-proof
or anticorrosion, and an adherend that does not necessarily require
re-peeling of the adhered sheet, which are the adhesion targets of
the pressure-sensitive adhesive layer 3 of sheet 10 in the first
form, and one of the two elastomer layers 1 having a Shore A
hardness of less than 40 of sheet 11 in the second form, are not
particularly limited, and members of various materials in various
forms can be mentioned.
[0061] In sheet 10 in the first form, for example, moisture-proof
of floor panel and airframe constructional material can be
achieved, as well as floor panel and airframe constructional
material can be temporarily fixed (permanently fixed by fastening
screw after temporary fixing) by adhering the surface of elastomer
layer 1 having a Shore A hardness of less than 40 to a floor panel
and adhering the surface of pressure-sensitive adhesive layer 3 to
an airframe constructional material. Particularly, in the case of a
sheet wherein a release liner is laminated on an elastomer layer
having a Shore A hardness of less than 40, a pressure-sensitive
adhesive layer having the release liner is adhered to the floor
panel, and the release liner is peeled off, the floor panel is
placed on and pressed against an airframe constructional material
with the elastomer layer having a Shore A hardness of less than 40
being opposed to the airframe constructional material, whereby the
floor panel and airframe constructional material become
moisture-proof and the floor panel can be simultaneously laid on
the airframe constructional material. Therefore, a floor panel
laying work can be performed efficiency. A technique including
adhering a pressure-sensitive adhesive layer to an airframe
constructional material in advance and mounting a floor panel on an
elastomer layer is also possible.
[0062] In single-faced adhesive sheets 13, 14 (FIGS. 5(A), 5(B),
6(A) and 6(B)) in the fourth and fifth forms, one of the surface
layers is elastomer layer 1 having a Shore A hardness of less than
40, and the other surface layer is substrate 5. Substrate 5 imparts
a sheet with self-supporting property, and improves resistance of
the sheet to water permeability. Since elastomer layer 1 having a
Shore A hardness of less than 40 shows superior adhesion to an
adherend, and substrate 5 increases resistance of the sheet to
water permeability, when the sheet is adhered to an adherend to be
moisture-proof, the adherend can be isolated from humidity and
water (including salt water) more effectively. In addition,
substrate 5 increases the strength of the sheet (tensile strength,
tear strength etc.), and an effect of suppressing tearing during
adhesion and peeling of the sheet can be obtained.
[0063] Each layer of the sheet of the present invention is
explained in detail for each sheet of each embodiment. [0064] (1)
Sheet 10 in the first form (sheet having laminate constitution of
elastomer layer 1 having a Shore A hardness of less than 40/core
film 2/pressure-sensitive adhesive layer 3)
<Elastomer Layer 1 Having a Shore A Hardness of Less Than
40>
[0065] The "elastomer layer" in the present invention is a concept
including not only a rubber layer formed from a rubber which is a
polymer substance having elasticity due to a crosslinked structure,
but also a layer formed from an uncrosslinked polymer substance
showing the property of rubber elastic body at ambient
temperature.
[0066] From the aspect of temporal stability of hardness, elastomer
layer 1 having a Shore A hardness of less than 40 is preferably a
rubber layer having Shore A hardness of less than 40, and from the
aspects of durability, flame retardancy, waterproof property and
the like of the material, a silicone rubber layer or urethane
rubber layer having a Shore A hardness of less than 40 is more
preferable, and a silicone rubber layer having a Shore A hardness
of less than 40 is particularly preferable.
[0067] As the silicone rubber layer having a Shore A hardness of
less than 40, a silicone rubber having a Shore A hardness of less
than 40 which is obtained by curing a conventionally-known silicone
rubber composition can be applied. While the silicone rubber
composition may be of any curing type, since forming can be
achieved in a short time by heating, one obtained from an addition
(hydrosilylation) reaction curing type silicone rubber composition
or an organic peroxide curing type silicone rubber composition is
preferable. The addition reaction curing type silicone rubber
composition may have a known composition, and one containing
alkenyl group-containing organopolysiloxane having two or more
alkenyl groups represented by a vinyl group in one molecule,
organohydrogen polysiloxane having two or more, preferably three or
more, SiH groups (generally, in an amount corresponding to molar
ratio of SiH group of 0.5-4 to alkenyl group), and platinum or a
platinum group metal addition reaction catalyst represented by a
platinum compound (generally, 1-1,000 ppm relative to alkenyl
group-containing organopolysiloxane) is used. In addition, an
organic peroxide curing type silicone rubber composition may be a
known composition, and organopolysiloxane having two or more
alkenyl groups in one molecule added with a cure effective amount
(generally, 1-10 parts by mass per 100 parts by mass of the
above-mentioned organopolysiloxane) of organic peroxide as a curing
agent is preferably used. A silicone rubber having a Shore A
hardness of less than 40 may be a commercially available product
and, for example, SILBIONE LSR 6301 (Shore A hardness: 1), LSR 6305
(Shore A hardness: 5) manufactured by Bluestar Silicones, Elastosil
3003/30 (Shore A hardness: 30) manufactured by Wacker Chemie, 3631
(Shore A hardness: 19) manufactured by DOW, and the like can be
mentioned.
[0068] The urethane rubber layer having a Shore A hardness of less
than 40 is a layer formed from a cured product having a Shore A
hardness of less than 40 (urethane rubber) obtained by reacting and
curing a polyurethane composition. To make the hardness of the
urethane rubber show a Shore A hardness of less than 40, the
composition of the polyurethane composition only needs to be
appropriately selected.
[0069] The polyurethane composition is composed of polyisocyanate
such as diisocyanate or triisocyanate and the like and polyol such
as diol or triol and the like.
[0070] The above-mentioned polyisocyanate is not particularly
limited, and examples thereof include diisocyanates such as
4,4'-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate
(2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI),
3,3'-bitolylene-4,4'-diisocyanate,
3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 2,4-tolylene
diisocyanate uretidinedione (2,4-TDI dimer), 1,5-naphthylene
diisocyanate, methaphenylene diisocyanate, hexamethylene
diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane
diisocyanate (hydrogenated MDI), carbodiimide-modified MDI,
orthotoluidine diisocyanate, xylene diisocyanate, paraphenylene
diisocyanate, lysine diisocyanate methyl ester and the like,
triisocyanates such as triphenylmethane-4,4',4''-triisocyanate and
the like, polymeric MDI and the like. These may be used alone or
two or more kinds thereof may be used in combination.
[0071] The polyol to be used along with the above-mentioned
polyisocyanate is not particularly limited, and examples thereof
include polyester polyol such as polyester diol, polyester triol
and the like, polycaprolactone, polycarbonate, polyetherpolyol such
as polyoxytetramethylene glycol, polyoxypropylene glycol and the
like, and the like. These may be used alone or two or more kinds
thereof may be used in combination.
[0072] As the above-mentioned polyester polyol, hydroxylpolyester
polyol produced from polybasic organic acid and polyol and having a
hydroxyl group as the terminal group is preferably used. Examples
of the above-mentioned polybasic organic acid include dicarboxylic
acids such as saturated fatty acids such as oxalic acid, succinic
acid, glutaric acid, adipic acid, pimelic acid, suberic acid,
azelaic acid, sebacic acid, isosebacic acid and the like,
unsaturated fatty acids such as maleic acid, fumaric acid and the
like, aromatic acids such as phthalic acid, isophthalic acid,
terephthalic acid and the like, and the like, acid anhydrides such
as maleic anhydride, phthalic anhydride and the like, dialkyl
esters such as dimethyl terephthalate and the like, dimer acid
obtained by dimerization of unsaturated fatty acid and the like.
Examples of the polyol to be used along with the above-mentioned
polybasic organic acid include diols such as ethylene glycol,
diethylene glycol, triethylene glycol, propylene glycol,
dipropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexylene
glycol and the like, triols such as trimethylolethane,
trimethylolpropane, hexane triol, glycerol and the like, hexaols
such as sorbitol and the like, and the like.
[0073] As the above-mentioned polyetherpolyol, one produced by ring
opening polymerization or copolymerization of cyclic ether is
preferably used. Examples of the above-mentioned cyclic ether
include ethylene oxide, propylene oxide, trimethylene oxide,
butylene oxide, .alpha.-methyltrimethylene oxide,
3,3'-dimethyltrimethylene oxide, tetrahydrofuran, dioxane, dioxamin
and the like.
[0074] The number average molecular weight (Mn) of polyol to be
used along with the above-mentioned polyisocyanate is preferably
1500-3000, particularly preferably 1500-2500. That is, when the
above-mentioned polyol has an Mn of less than 1500, the property of
the obtained urethane rubber layer tends to decrease, and when Mn
exceeds 3000, the workability tends to be degraded.
[0075] The polyurethane composition may appropriately contain, in
addition to polyisocyanate and polyol, chain extender, catalyst,
foaming agent, surfactant, flame retardant, colorant, filler,
plasticizer, stabilizer, mold release agent and the like.
[0076] A urethane rubber layer is formed by reacting and curing a
polyurethane composition by cast molding (specifically, prepolymer
method, semi-one-shot method, one-shot method) to give a sheet-like
cured product.
[0077] Elastomer layer 1 having a Shore A hardness of less than 40
can contain a flame retardant. While the flame retardant is not
particularly limited, a halogen-free flame retardant which does not
produce a toxic halogen gas, is preferable and, for example, known
flame retardants free of halogen atom such as hydrated metal
compound-based flame retardants, inorganic compound-based flame
retardants, phosphorus flame retardant, silicone-based flame
retardant, nitrogen compound-based flame retardants, organic metal
compound-based flame retardants and the like can be used. Of these,
phosphorus flame retardants are preferable since they can impart a
flame retardancy effect and are superior in the suppression of drip
during combustion, compatibility to environmental regulation and
the like. For example, when an elastomer layer is a silicone rubber
layer or a urethane rubber layer, the aforementioned silicone
rubber composition or polyurethane composition can contain a flame
retardant. Depending on the kind of the flame retardant, a flame
retardant is preferably contained in about 10-100 parts by weight
per 100 parts by weight of the silicone rubber composition or
polyurethane composition.
[0078] To obtain sheet 10 in the first form having an elastomer
layer 1 having a Shore A hardness of less than 40 and an adhesion
force to stainless steel of not more than 11 oz/in at 90 degree
peel strength, the thickness of the elastomer layer 1 having a
Shore A hardness of less than 40 is preferably 2-40 mil, more
preferably 15-35 mil. When the thickness of the elastomer layer 1
is within such preferable range, the maintenance of a wrapped state
of a roll product and handling property as a tape become more
superior.
<Core Material 2>
[0079] The material of core material 2 is not particularly limited.
Examples thereof include a single layer or laminate plastic film
made from one or more kinds selected from polyester (e.g.,
poly(ethylene terephthalate) (PET) and the like); nylon; polyvinyl
chloride; polyvinylidene chloride; polyolefin (e.g., polyethylene,
polypropylene, reactor TPO, ethylene-vinyl acetate copolymer and
the like); fluororesin (e.g., polytetrafluoroethylene (PTFE),
polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride
(PVDF), polyvinyl fluoride (PVF), perfluoroalkoxy fluororesin
(PFA), tetrafluoroethylene hexafluoropropylene copolymer (FEP),
ethylene tetrafluoroethylene copolymer (ETFE), ethylene
chlorotrifluoroethylene copolymer (ECTFE) and the like) and the
like, a metal foil, and the like. Also, it may be a film obtained
by laminating a plastic film and a metal foil. These films may be
used in a solid film (nonporous film) state, or a perforated film
after a mechanical perforation treatment. A fiber sheet (a single
layer sheet, laminated sheet of two or more layers) such as knitted
fabric, woven fabric, non-woven fabric and the like using one or
more kinds of fibers selected from synthetic polymer fibers such as
polyester (e.g., poly(ethylene terephthalate) (PET) and the like)
and the like, natural fibers such as cotton, hemp and the like,
metal fiber and glass fiber, and a laminated sheet wherein one or
more kinds of such fiber sheets are laminated on the aforementioned
plastic film can also be used as a substrate sheet 1. In addition,
glass cloth, Japanese paper, non-fiber paper and the like can also
be used as a core material 2. Of these, from the aspects of the
resistance of the sheet to water permeability (moisture-barrier
property), one having less air holes through which the moisture
passes is preferable, and a nonporous film is preferable. The
"nonporous film" means a solid film excluding mesh cloth, woven
fabric, non-woven fabric, mesh film (sheet), perforated film
(sheet) and the like. From the aspects of moisture-proof property,
flame retardancy, flexibility and the like, preferred is a
fluororesin film (solid), and more preferred is a PTFE film
(solid).
[0080] For penetrate bolting after sheet configuration and the
like, from the aspects of workability of bolting, imparting
strength on peeling and the like, a glass fiber sheet (particularly
glass cloth) is preferable.
[0081] The fabric weight of glass fiber sheet is preferably 5-1000
g/m.sup.2 from the aspects of the strength and transparency of the
sheet, and the thickness (diameter) of the glass fiber is
preferably abut 0.4-39 mil. In the case of a glass cloth, the form
thereof may be, for example, plain weave, satin weave, 5 twill
weave, mat weave and the like. The adhesiveness of the glass cloth
to an elastomer layer can be improved by a surface treatment with a
silane coupling agent.
[0082] While the thickness of the core material 2 is not
particularly limited, to obtain sheet 10 in the first form having
an elastomer layer 1 having a Shore A hardness of less than 40 and
an adhesion force to stainless steel of not more than 11 oz/in at
90 degree peel strength, 0.5-10 mil is preferable, 2-7 mil is more
preferable. While the thickness of the core material 2 is within
such preferable range, the maintenance of a wrapped state of a roll
product and handling efficiency as a tape are further improved.
<Pressure-Sensitive Adhesive Layer 3>
[0083] The pressure-sensitive adhesive to be used for the
pressure-sensitive adhesive layer 3 is not particularly limited,
and acrylic, silicone-based, natural rubber-based, synthetic
rubber-based, polyoxyalkylene-based adhesives and the like can be
mentioned. Of these, a polyoxyalkylene-based adhesive is
preferable. The polyoxyalkylene-based adhesive is superior in high
adhesion force, moisture-proof property, and concave convex
adaptability.
(Acrylic Adhesive)
[0084] Specifically, as the acrylic adhesive, an acrylic adhesive
containing, as a base polymer, an acrylic polymer with a monomer
unit of alkyl(meth)acrylate as a main backbone is preferable (here,
the "(meth)acrylate" means "acrylate and/or methacrylate").
[0085] The average carbon number of the alkyl group of the
alkyl(meth)acrylate constituting the main backbone of the acrylic
polymer is preferably about 1 to 18. Specific examples of such
alkyl(meth)acrylate include methyl(meth)acrylate, 5
ethyl(meth)acrylate, n-butyl(meth)acrylate,
2-ethylhexyl(meth)acrylate, isooctyl(meth)acrylate, isononyl
(meth)acrylate, lauryl (meth)acrylate and the like. One or more
kinds of these are used in combination. Among these,
alkyl(meth)acrylate wherein the carbon number of the alkyl group is
1 to 12 is preferable.
[0086] One or more kinds of various monomers may be introduced into
an acrylic polymer by copolymerization to improve adhesiveness to a
sealed object and heat resistance of the pressure-sensitive
adhesive sheet containing a non-halogenated flame retardant.
Specific examples of such copolymerizable monomer include monomers
containing a hydroxyl group such as 2-hydroxyethyl (meth)acrylate,
2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth) acrylate,
6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth)acrylate,
10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth) acrylate,
(4-hydroxymethylcyclohexyl)methyl (meth)acrylate and the like;
monomers containing a carboxyl group such as (meth)acrylic acid,
carboxyethyl(meth)acrylate, carboxypentyl(meth)acrylate, itaconic
acid, maleic acid, fumaric acid, crotonic acid and the like;
monomers containing an acid anhydride group such as maleic
anhydride, itaconic anhydride and the like; caprolactone adduct of
acrylic acid; monomers containing a sulfonic acid group such as
styrenesulfonic acid, allylsulfonic acid,
2-(meth)acrylamide-2-methylpropanesulfonic acid,
(meth)acrylamidepropanesulfonic acid, sulfopropyl (meth) acrylate,
(meth) acryloyloxynaphthalenesulfonic acid and the like; monomers
containing a phosphate group such as 2-(phosphonooxy)ethyl acrylate
etc., and the like. In addition, nitrogen containing vinyl monomers
can be mentioned, for example, 35 maleimide, N-cyclohexylmaleimide,
N-phenylmaleimide; N-acryloylmorpholine; (N-substituted) amide
monomers such as (meth) acrylamide, N,N-dimethyl(meth)acrylamide,
N,N-diethyl(meth)acrylamide, N-hexyl(meth)acrylamide,
N-methyl(meth)acrylamide, N-butyl(meth)acrylamide,
N-5butyl(meth)acrylamide, N-methylol(meth)acrylamide,
N-methylolpropane(meth)acrylamide and the like; alkylaminoalkyl
(meth)acrylate monomers such as aminoethyl (meth)acrylate,
aminopropyl (meth) acrylate, N,N-dimethylaminoethyl (meth)
acrylate, t-butylaminoethyl (meth) acrylate,
3-(3-pyridinyl)propyl(meth)acrylate and the like; alkoxyalkyl
(meth)acrylate monomers such as methoxyethyl (meth)acrylate,
ethoxyethyl (meth)acrylate and the like; succinimide monomers such
as N-(meth)acryloyloxymethylenesuccinimide,
N-(meth)acryloyl-6-oxyhexamethylenesuccinimide,
N-(meth)acryloyl-8-oxyoctamethylenesuccinimide,
N-acryloylmorpholine etc., and the like can be mentioned.
[0087] Furthermore, vinyl monomers such as vinyl acetate, vinyl
propionate, N-vinylpyrrolidone, methylvinylpyrrolidone,
vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine,
vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole,
vinylmorpholine, N-vinylcarboxylic acid amides, styrene,
.alpha.-methylstyrene, N-vinylcaprolactam and the like;
cyanoacrylate monomers such as acrylonitrile, methacrylonitrile and
the like; epoxy group-containing acrylic monomers such as glycidyl
(meth)acrylate and the like; glycol acrylate monomers such as
polyethylene glycol (meth)acrylate, polypropylene glycol (meth)
acrylate, methoxyethylene glycol (meth) acrylate,
methoxypolypropylene glycol (meth)acrylate and the like; acrylate
monomers such as tetrahydrofurfuryl (meth)acrylate,
fluorine-containing (meth) acrylate, silicone (meth) acrylate,
2-methoxyethyl acrylate etc., and the like can also be
mentioned.
[0088] Among these, when an isocyanate-based crosslinking agent is
used as a crosslinking agent, a hydroxyl group-containing monomer
is preferable since the reactivity with the isocyanate group is
good. Carboxyl group-containing monomers such as (meth)acrylic acid
and the like are preferable in view of the adhesiveness to a sealed
object, adhesion durability, weatherability and the like of the
flame retardant-containing pressure-sensitive adhesive sheet, and
acrylic acid is particularly preferable.
[0089] The weight ratio of the copolymerizable monomer in the
acrylic polymer is preferably about 0.1-10 wt %.
[0090] While the average molecular weight of the acrylic polymer is
not particularly limited, the weight average molecular weight is
generally about 300,000 to 2,500,000.
[0091] Acrylic polymers are produced by various known methods and,
for example, radical polymerization methods such as bulk
polymerization method, solution polymerization method, suspension
polymerization method and the like can be appropriately employed.
As a radical polymerization initiator, various known azo-based
initiators and peroxide-based initiators can be used. The reaction
temperature is generally about 50 to 80.degree. C., and the
reaction time is 1 to 8 hr.
[0092] The acrylic adhesive can contain a crosslinking agent in
addition to a base polymer, and the crosslinking agent can improve
adhesion to an optical board and durability, and can provide
reliability at a high temperature and maintain the form of the
adhesive itself. As the crosslinking agent, a known crosslinking
agent such as isocyanate-based crosslinking agents, epoxy-based
crosslinking agents, peroxide-based crosslinking agents, metal
chelate-based crosslinking agents, oxazoline-based crosslinking
agents and the like can be appropriately used. One or more kinds of
these crosslinking agents can be used in combination. The amount of
the crosslinking agent to be used is not more than 10 parts by
weight, preferably 0.01-5 parts by weight, more preferably 0.02-3
parts by weight, relative to 100 parts by weight of the acrylic
polymer. A ratio of the crosslinking agent exceeding 10 parts by
weight is not preferable, since crosslinking may proceed too much
to decrease adhesiveness.
(Silicone-Based Adhesive)
[0093] The silicone-based adhesive is not particularly limited, and
peroxide crosslinking type silicone-based adhesives (peroxide
curing type silicone-based adhesive) and addition reaction type
silicone-based adhesives, which are generally used, can be
preferably used. These peroxide crosslinking type silicone-based
adhesives and addition reaction type silicone-based adhesives may
be commercially available products. Specific examples of the
peroxide crosslinking type silicone-based adhesive include
KR-3006A/BT manufactured by Shin-Etsu Chemical Co., Ltd., SH 4280
PSA manufactured by Toray Dow Corning Corporation Silicone and the
like. Specific examples of the addition reaction type
silicone-based adhesive include X-40-3501 manufactured by Shin-Etsu
Chemical Co., Ltd., BY 24-712 manufactured by Toray Dow Corning
Corporation Silicone, TSE32X manufactured by GE Toshiba Silicones
Co., Ltd. and the like.
(Polyoxyalkylene-Based Adhesive)
[0094] As the polyoxyalkylene-based adhesive, a cured product of a
composition containing the following components A-C is
preferable:
[0095] A: a polyoxyalkylene polymer having at least one alkenyl
group in one molecule
[0096] B: a compound containing two or more hydrosilyl groups on
average in one molecule
[0097] C: a hydrosilylation catalyst.
[0098] The above-mentioned "polyoxyalkylene polymer having at least
one alkenyl group in one molecule" of component A is not
particularly limited, and various polymers can be used. However,
one wherein the main chain of the polymer has a repeat unit
represented by the formula (1) shown below is preferable:
--R.sup.1--O-- formula (1)
wherein R.sup.1 is an alkylene group.
[0099] R.sup.1 is preferably a linear or branched alkylene group
having 1 to 14, more preferably 2 to 4, carbon atoms.
[0100] As specific examples of the repeat unit represented by the
general formula (1), --CH.sub.2O--, --CH.sub.2CH.sub.2O--,
--CH.sub.2CH(CH.sub.3)O--, --CH.sub.2CH(C.sub.2H.sub.5)O--,
--CH.sub.2C(CH.sub.3).sub.2O--,
--CH.sub.2CH.sub.2CH.sub.2CH.sub.2O--and the like can be included.
The main chain skeleton of the polyoxyalkylene polymer may consist
of only one kind of repeat unit, and may consist of two kinds or
more of repeat units. Particularly, from the aspects of
availability and workability, a polymer having
--CH.sub.2CH(CH.sub.3)O-- as a main repeat unit is preferable. In
the main chain of the polymer, a repeat unit other than the
oxyalkylene group may be contained. In this case, the total sum of
oxyalkylene units in the polymer is preferably not less than 80% by
weight, particularly preferably not less than 90% by weight.
[0101] Although the polymer of component A may be a linear polymer
or a branched polymer, or a mixture thereof, it preferably contains
a linear polymer in a proportion of not less than 50% by weight, so
that the adhesive layer will show good adhesiveness to the surface
of various materials.
[0102] The molecular weight of the polymer of component A is
preferably 500 to 50,000, more preferably 5,000 to 30,000, in terms
of number-average molecular weight. When the number average
molecular weight is less than 500, the obtained cured product tends
to be too brittle, and when the number average molecular weight
exceeds 50,000, the viscosity becomes unfavorably too high to
markedly decrease workability. The number average molecular weight
here means the value obtained by a gel permeation chromatography
(GPC) method.
[0103] The polymer of component A preferably has a narrow molecular
weight distribution wherein the ratio of weight-average molecular
weight and number-average molecular weight (Mw/Mn) is not more than
1.6; a polymer having an Mw/Mn of not more than 1.6 produces a
decreased viscosity of the composition and offers improved
workability. Hence, the Mw/Mn is more preferably not more than 1.5,
still more preferably not more than 1.4. As mentioned herein, Mw/Mn
refers to a value obtained by a gel permeation chromatography (GPC)
method.
[0104] Here, the molecular weight (based on polystyrene) is
measured by the GPC method using GPC apparatus (HLC-8120GPC)
manufactured by Tosoh Corporation, where the measurement conditions
are as follows.
[0105] sample concentration: 0.2 wt % (THF solution)
[0106] sample injection volume: 10 .mu.l
[0107] eluent: THF
[0108] flow rate: 0.6 ml/min
[0109] measurement temperature: 40.degree. C.
[0110] column: sample column TSKgel GMH-H(S)
[0111] detector: differential refractometer
[0112] With regard to the polymer of component A (polyoxyalkylene
polymer having at least one alkenyl group in one molecule), the
alkenyl group is not subject to limitation, but an alkenyl group
represented by the formula (2) shown below is suitable:
H.sub.2C.dbd.C(R.sup.2)-- formula (2)
wherein R.sup.2 is hydrogen or a methyl group.
[0113] The mode of binding of the alkenyl group to the
polyoxyalkylene polymer is not subject to limitation; for example,
alkenyl group direct bond, ether bond, ester bond, carbonate bond,
urethane bond, urea bond and the like can be included.
[0114] As specific examples of the polymer of component A, a
polymer represented by the formula (3):
{H.sub.2C.dbd.C(R.sup.3a)--R.sup.4a--O}a.sub.1R.sup.5a wherein
R.sup.3a is hydrogen or a methyl group; R.sup.4a is a divalent
hydrocarbon group having 1 to 20 carbon atoms, optionally having
one or more ether groups, R.sup.5a is a polyoxyalkylene polymer
residue; a.sub.1 is a positive integer, can be included. As
R.sup.4a in the formula, specifically, --CH.sub.2--,
--CH.sub.2CH.sub.2--, --CH.sub.2CH.sub.2CH.sub.2--,
--CH.sub.2CH(CH.sub.3)CH.sub.2--,
--CH.sub.2CH.sub.2CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2OCH.sub.2CH.sub.2--, or
--CH.sub.2CH.sub.2OCH.sub.2CH.sub.2CH.sub.2-- and the like can be
included; for the ease of synthesis, --CH.sub.2--is preferable.
[0115] A polymer having an ester bond, represented by the formula
(4): {H.sub.2C.dbd.C(R.sup.3b)--R.sup.4b--OCO}a.sub.2R.sup.5b
wherein R.sup.3b, R.sup.4b, R.sup.5b and a.sub.2 have the same
definitions as those of R.sup.3a, R.sup.4a, R.sup.5a, and a.sub.1,
respectively, can also be included.
[0116] A polymer represented by the formula (5):
{H.sub.2C.dbd.C(R.sup.3c)}a.sub.3R.sup.5c wherein R.sup.3c,
R.sup.5cand a.sub.3 have the same definitions as those of R.sup.3a,
R.sup.5a, and a.sub.1, respectively, can also be included.
[0117] Furthermore, a polymer having a carbonate bond, represented
by the formula (6):
{H.sub.2C.dbd.C(R.sup.3d)--R.sup.4d--O(CO)O}a.sub.4R.sup.5d wherein
R.sup.3d, R.sup.4d, R.sup.5d and a.sub.4 have the same definitions
as those of R.sup.3a, R.sup.4a, R.sup.5a and a.sub.1, respectively,
can also be included.
[0118] It is preferable that at least 1, preferably 1 to 5, more
preferably 1.5 to 3, alkenyl groups be present in one molecule of
the polymer of component A. If the number of alkenyl groups
contained in one molecule of the polymer of component A is less
than 1, the curing is insufficient; if the number exceeds 5, the 5
mesh structure becomes so dense that the polymer sometimes fails to
exhibit a good adherence. The polymer of component A can be
synthesized according to the method described in JP-A-2003-292926,
and any commercially available product can be used.
[0119] Particularly preferable embodiment of the polymer of
component A includes terminus-allylated polyoxypropylene wherein an
allyl group is bonded to both terminals of polypropylene
glycol.
[0120] Any component B "compound containing two or more hydrosilyl
groups on average in one molecule" can be used without limitation,
as long as it has a hydrosilyl group (a group having an Si-H bond),
but from the viewpoint of the ease of obtainment of raw materials
and compatibility with the component A, an organohydrogen
polysiloxane modified with an organic constituent is particularly
preferable. The aforementioned polyorganohydrogen siloxane modified
with an organic constituent more preferably has an average of 2 to
8 hydrosilyl groups in one molecule. Specific examples of the
structure of the polyorganohydrogen siloxane include linear or
cyclic ones represented by, for example,
##STR00001##
wherein 2.ltoreq.m.sub.1+n.sub.1.ltoreq.50, 2.ltoreq.m.sub.1, and
0.ltoreq.n.sub.1, R.sup.6a is a hydrocarbon group having 2 to 20
carbon atoms in the main chain thereof, optionally comprising one
or more phenyl groups,
##STR00002##
wherein 0.ltoreq.m.sub.2+n.sub.2.ltoreq.50, 0.ltoreq.m.sub.2, and
0.ltoreq.n.sub.2, R.sup.6b is a hydrocarbon group having 2 to 20
carbon atoms in the main chain thereof, optionally comprising one
or more phenyl groups, or
##STR00003##
wherein 3.ltoreq.m.sub.3.ltoreq.n.sub.3.ltoreq.20,
2.ltoreq.m.sub.3.ltoreq.19, and 0.ltoreq.n.sub.3.ltoreq.18,
R.sup.6c is a hydrocarbon group having 2 to 20 carbon atoms in the
main chain thereof, optionally having one or more phenyl groups,
and the like, and ones having two or more of these units,
represented by the following:
##STR00004##
wherein 1.ltoreq.m.sub.4+n.sub.4.ltoreq.50, 1.ltoreq.m.sub.4, and
0.ltoreq.n.sub.4, R.sup.6d is a hydrocarbon group having 2 to 20
carbon atoms in the main chain thereof, optionally having one or
more phenyl groups, 2.ltoreq.b.sub.1, R.sup.8a is a divalent to
tetravalent organic group, and R.sup.7a is a divalent organic
group, but R.sup.7a may be absent depending on the structure of
R.sup.8a,
##STR00005##
wherein 0.ltoreq.m.sub.5+n.sub.5.ltoreq.50, 0.ltoreq.m.sub.5, and
0.ltoreq.n.sub.5, R.sub.6e is a hydrocarbon group having 2 to 20
carbon atoms in the main chain thereof, optionally having one or
more phenyl groups, 2.ltoreq.b.sub.2, R.sup.8b is a divalent to
tetravalent organic group, and R.sup.7b is a divalent organic
group, however, R.sup.7b may be absent depending on the structure
of R.sup.8b, or
##STR00006##
wherein 3.ltoreq.m.sub.6+n.sub.6.ltoreq.50, 1.ltoreq.m.sub.6, and
0.ltoreq.n.sub.6, R.sup.6f is a hydrocarbon group having 2 to 20
carbon atoms in the main chain thereof, optionally comprising one
or more phenyl groups, 2.ltoreq.b.sub.3, R.sup.8c is a divalent to
tetravalent organic group, and R.sup.7c is a divalent organic
group, however, R.sup.7c may be absent depending on the structure
of R.sup.8c, and the like.
[0121] The "compound containing two or more hydrosilyl groups on
average in one molecule" for component B preferably has good
compatibility with the component A and the component C, or good
dispersion stability in the system. Particularly, if the viscosity
of the entire system is low, use of an ingredient whose
compatibility with any of the above-described ingredients is low as
the component B sometimes causes phase separation and a curing
failure.
[0122] As a specific example of the component B having relatively
good compatibility with the component A and the component C, or
relatively good dispersion stability, the following can be
included.
##STR00007##
wherein n.sub.7 is an integer of not less than 4 and not more than
10,
##STR00008##
wherein 2.ltoreq.m.sub.8.ltoreq.10 and 0.ltoreq.n.sub.8.ltoreq.5,
R.sup.6g is a hydrocarbon group having eight or more carbon
atoms.
[0123] As specific preferable examples of the component B,
polymethylhydrogen siloxane can be included; for assuring
compatibility with the component A and adjusting the SiH content, a
compound modified with .alpha.-olefin, styrene,
.alpha.-methylstyrene, allylalkyl ether, allylalkyl ester,
allylphenyl ether, allylphenyl ester or the like can be included;
as an example, the following structure can be included.
##STR00009##
wherein 2.ltoreq.m.sub.9.ltoreq.20 and
1.ltoreq.n.sub.9.ltoreq.20.
[0124] The component B can be synthesized by a commonly known
method, and any commercially available product can be used.
[0125] In the present invention, any component C "hydrosilylation
catalyst" is not subject to limitation; an optionally chosen one
can be used. As specific examples, chloroplatinic acid; elemental
platinum; solid platinum supported by a carrier such as alumina,
silica, or carbon black; a platinum-vinylsiloxane complex {for
example, Pt.sub.n(ViMe.sub.2SiOSiMe.sub.2Vi).sub.m,
Pt[(MeViSi).sub.4].sub.m and the like}; a platinum-phosphine
complex {for example, Pt(PPh.sub.3).sub.4, Pt(PBu.sub.3).sub.4 and
the like}; a platinum-phosphite complex {for example,
Pt[P(OPh).sub.3].sub.4, Pt[P(OBu).sub.3].sub.4 and the like};
Pt(acac).sub.2; the platinum-hydrocarbon composite described in US
Patent 3159601 and 3159662 of Ashby et al.; the platinum alcoholate
catalyst described in US. Pat. No. 3,220,972 of Lamoreaux et al.
and the like can be included. (In these formulas, Me represents a
methyl group, Bu represents a butyl group, Vi represents a vinyl
group, Ph represents a phenyl group, acac represents an
acetylacetonato, and each of n and m represents an integer.)
[0126] As examples of catalysts other than platinum compounds,
RhCl(PPh.sub.3).sub.3, RhCl.sub.3, Rh/Al.sub.2O.sub.3, RuCl.sub.3,
IrCl.sub.3, FeCl.sub.3, AlCl.sub.3, PdCl.sub.2.2H.sub.2O,
NiCl.sub.2, TiCl.sub.4 and the like can be included.
[0127] These catalysts may be used alone, and may be used in
combination of two kinds or more. With regard to catalyst activity,
chloroplatinic acid, a platinum-phosphine complex, a
platinum-vinylsiloxane complex, Pt(acac)2 and the like are
preferable.
[0128] Although the amount of the component C formulated is not
subject to limitation, from the viewpoint of assurance of
composition potlife and transparency of the cured product (adhesive
layer), the amount is generally not more than 1.times.10.sup.-1
mol, preferably not more than 5.3.times.10.sup.-2 mol, relative to
1 mol of alkenyl groups in the component A; particularly, from the
viewpoint of transparency of the cured product (adhesive layer),
the amount is more preferably not more than 3.5.times.10.sup.-2
mol, particularly preferably not more than 1.4.times.10.sup.-3 mol.
When the amount exceeds 1.times.10.sup.-1 mol relative to 1 mol of
alkenyl groups in the component A, the finally obtained cured
product (adhesive layer) is likely to undergo yellowing and the
transparency of the cured product (adhesive layer) tends to be
damaged. When the amount of the component C formulated is too low,
the composition curing speed is slow, and the curability tends to
be unstable; therefore, the amount is preferably not less than
8.9.times.10.sup.-5 mol, more preferably not less than
1.8.times.10.sup.-4 mol.
[0129] The composition comprising the above-described components A
to C is cured by heating. That is, the alkenyl group of component A
(polyoxyalkylene polymer having at least one alkenyl group in one
molecule) is hydrosilylated by the hydrosilyl group (group having
Si-H bond) of component B (compound containing two or more
hydrosilyl groups on average in one molecule) in the 35 presence of
a hydrosilylation catalyst (component C) to allow crosslinking to
proceed, whereby curing is completed. The cured product has low
activity, and does not react upon contact with various substances
such as water, metal, plastic material and the like.
[0130] In a composition comprising components A to C, it is
preferable that component A and component B be contained so that
the functional group ratio of the hydrosilyl groups groups of
component B (compound B) to the alkenyl groups of component A
(compound A) will be not less than 0.3 and less than 2, more
preferably not less than 0.4 and less than 1.8, and still more
preferably not less than 0.5 and less than 1.5. When the foregoing
functional group ratio will exceed 2, the crosslinking density
increases, and it is sometimes impossible to obtain adhesiveness.
When the functional group ratio is less than 0.3, crosslinking in
the cured product becomes too weak, and retention of
characteristics at high temperatures may become difficult.
[0131] The pressure-sensitive adhesive layer 3 can contain a flame
retardant. While the flame retardant is not particularly limited, a
halogen-free flame retardant which does not produce a toxic halogen
gas, is preferable and, for example, known flame retardants free of
halogen atom such as hydrated metal compound-based flame
retardants, inorganic compound-based flame retardants, phosphorus
flame retardant, silicone-based flame retardant, nitrogen
compound-based flame retardants, organic metal compound-based flame
retardants and the like can be used. Of these, phosphorus flame
retardants are preferable since they can impart a flame retardancy
effect and are superior in the suppression of drip during
combustion, compatibility to environmental regulation and the like.
While the amount thereof to be used varies depending on the kind of
the flame retardant, it is preferably about 10-100 parts by weight
per 100 parts by weight of the adhesive.
[0132] The pressure-sensitive adhesive layer 3 can contain a
tackifier resin. Examples of the tackifier resin include terpene
tackifier resin, phenol-based tackifier resin, rosin-based
tackifier resin, petroleum-based tackifier resin and the like. One
or more kinds of tackifier resin can be used.
[0133] Examples of the terpene-based tackifier resin include
terpene-based resins such as .alpha.-pinene polymer, .beta.-pinene
polymer, dipentene polymer and the like, modified terpene-based
resins (e.g., terpenephenol-based resin, styrene-modified
terpene-based resin, aromatic-modified terpene-based resin,
hydrogenated terpene-based resin etc.) obtained by modifying
(phenol-modification, aromatic-modification,
hydrogenated-modification, hydrocarbon-modification etc.) these
terpene-based resins, and the like.
[0134] Examples of the phenol-based tackifier resin include
condensates (e.g., alkylphenolic resin, xyleneformaldehyde-based
resin and the like) of various phenols (e.g., phenol, m-cresol,
3,5-xylenol, p-alkylphenol, resorcin etc.) and formaldehyde, resol
obtained by addition reaction of the aforementioned phenols with
formaldehyde using an alkali catalyst, novolac obtained by
condensation reaction of the aforementioned phenols with
formaldehyde using an acid catalyst and the like.
[0135] Examples of the rosin-based tackifier resin include
unmodified rosin (natural rosin) such as gum rosin, wood rosin,
tall oil rosin and the like, modified rosin (hydrogenated rosin,
disproportionated rosin and polymerized rosin, and other
chemically-modified rosin etc.) obtained by modifying the above
unmodified rosins by hydrogenation, disproportionation
polymerization and the like, various rosin derivatives and the
like. Examples of the aforementioned rosin derivative include rosin
esters such as esterified compound of rosin obtained by esterifying
unmodified rosin with an alcohol and esterified compound of
modified rosin obtained by esterifying modified rosin, hydrogenated
rosin, disproportionated rosin, polymerized rosin and the like)
with an alcohol and the like; unsaturated fatty acid-modified
rosins obtained by modifying unmodified rosin or modified rosin
(hydrogenated rosin, disproportionated rosin, polymerized rosin
etc.) with unsaturated fatty acid; unsaturated fatty acid-modified
rosin ester obtained by modifying rosin ester with an unsaturated
fatty acid; rosin alcohols obtained by reduction-treating a
carboxyl group in unmodified rosin, modified rosin (hydrogenated
rosin, disproportionated rosin, polymerized rosin etc.),
unsaturated fatty acid-modified rosins or unsaturated fatty
acid-modified rosin esters; metal salts of rosins such as
unmodified rosin, modified rosin, various rosin derivatives and the
like (particularly, rosin esters); and the like. In addition, as
the rosin derivative, a rosin phenol resin obtained by adding
phenol to rosins (unmodified rosin, modified rosin, various rosin
derivatives etc.) with an acid catalyst and subjecting same to
thermal polymerization and the like can also be used.
[0136] Examples of the alcohol to be used for obtaining the
above-mentioned rosin esters include divalent alcohols such as
ethylene glycol, diethylene glycol, propylene glycol, neopentyl
glycol and the like, trivalent alcohols such as glycerol,
trimethylolethane, trimethylolpropane and the like, tetravalent
alcohols such as pentaerythritol, diglycerol and the like,
hexahydric alcohols such as dipentaerythritol etc. and the like.
These are used alone or in a combination of two or more kinds
thereof.
[0137] Examples of the petroleum-based tackifier resin include
known petroleum resins such as aromatic petroleum resin, aliphatic
petroleum resin, alicyclic petroleum resin (aliphatic cyclic
petroleum resin), aliphatic aromatic petroleum resin, aliphatic
alicyclic petroleum resin, hydrogenated petroleum resin, coumarone
resin, coumarone indene resin and the like. Specific examples of
the aromatic petroleum resin include polymers using one or more
kinds of vinyl group-containing aromatic hydrocarbon having 8 to 10
carbon atoms (styrene, o-vinyltoluene, m-vinyltoluene,
p-vinyltoluene, .alpha.-methylstyrene, .beta.-methylstyrene,
indene, methylidene etc.) and the like. As the aromatic petroleum
resin, an aromatic petroleum resin obtained from a fraction such as
vinyltoluene, indene and the like (i.e., "C9 petroleum fraction")
(namely, "C9 petroleum resin") can be used preferably. Examples of
the aliphatic petroleum resin include polymers obtained by using
one or more kinds selected from dienes such as olefin having 4 or 5
carbon atoms (e.g., butene-1, isobutylene, pentene-1 etc.),
butadiene, piperylene, 1,3-pentadiene, isoprene etc., and the like.
Furthermore, as the aliphatic petroleum resin, an aliphatic
petroleum resin obtained from a fraction such as butadiene,
piperylene, isoprene and the like (i.e., "C4 petroleum fraction",
"C5 petroleum fraction" etc.) (namely, "C4 petroleum resin", "C5
petroleum resin" etc.) can be used preferably. Examples of the
alicyclic petroleum resin include an alicyclic hydrocarbon resin
obtained by cyclization and dimerization of an aliphatic petroleum
resin (i.e., "C4 petroleum resin", "C5 petroleum resin" etc.),
followed by polymerization, a polymer of a cyclic diene compound
(cyclopentadiene, dicyclopentadiene, ethylidenenorbornane,
dipentene, ethylidenebicycloheptene, vinylcycloheptene,
tetrahydroindene, vinylcyclohexene, limonene etc.) or a
hydrogenated resin thereof, an alicyclic hydrocarbon resin obtained
by hydrogenating the aromatic ring of the aforementioned aromatic
hydrocarbon resin, the following aliphatic aromatic petroleum resin
and the like. Examples of the aliphatic aromatic petroleum resin
include a styrene-olefin copolymer and the like. In addition, as
the aliphatic aromatic petroleum resin, a so-called "C5/C9
copolymerization petroleum resin" and the like can be used.
[0138] The tackifier resin is preferably terpene-based tackifier
resin and/or rosin-based tackifier resin, particularly preferably
rosin-based tackifier resin, from the aspect of flame retardancy of
a sheet. The terpene tackifier resin and rosin-based tackifier
resin easily provide effect as flame retardant auxiliary agents.
Using these, adhesion of a sheet to an adherend and the flame
retardancy of a sheet can be improved. The terpene-based tackifier
resin is particularly preferably a terpenephenol resin, the
rosin-based tackifier resin is particularly preferably rosin ester
(i.e., esterified compound of unmodified rosin, hydrogenated rosin,
disproportionated rosin or polymerized rosin), and the rosin ester
is preferably trivalent or higher polyhydric alcohol ester,
particularly preferably tetra to hexahydric polyhydric alcohol
ester.
[0139] One or more kinds of the tackifier resins can be used in
combination, and the amount thereof to be used is not particularly
limited. However, it is preferably not less than 5 parts by weight,
more preferably not less than 10 parts by weight, particularly
preferably not less than 15 parts by weight, relative to 100 parts
by weight of the adhesive, since it becomes a carbon source and
sufficiently exhibits the effect of a phosphorus flame retardant as
an auxiliary agent. From the aspects of maintenance of adhesive
property, preservability, handling property, dispersibility and the
like, it is preferably not more than 100 parts by weight, more
preferably not more than 60 parts by weight, particularly
preferably not more than 40 parts by weight.
[0140] The pressure-sensitive adhesive layer 3 can contain, where
necessary, various additives such as plasticizer, filler made of
glass fiber, glass bead, metal powder, pigment, colorant,
antioxidant, UV absorber and the like.
[0141] To obtain sheet 10 in the first form having an elastomer
layer 1 having a Shore A hardness of less than 40 and an adhesion
force to stainless steel of not more than 11 oz/in at 90 degree
peel strength, the thickness of the pressure-sensitive adhesive
layer 3 s preferably 1-40 mil, more preferably 15-25 mil. When the
thickness of the pressure-sensitive adhesive layer 3 is within such
preferable range, the maintenance of a wrapped state of roll
products 51, 52 made of sheet 10 and handling efficiency and the
like as a sheet are further improved.
[0142] In the sheet 10 in the first form, the thickness of the
whole sheet, that is, the total thickness of elastomer layer 1
having a Shore A hardness of less than 40, core material 2 and
pressure-sensitive adhesive layer 3 is preferably 3-90 mil, more
preferably 30-70 mil. When the total thickness is within such
preferable range, the maintenance of a wrapped state of roll
products 51, 52 made of sheet 10 and handling efficiency and the
like as a sheet are further improved.
<Release Liner 4>
[0143] As release liner 4, (a) a release-treated layer with a
release agent is formed at least one face of a substrate for a
release liner, (b) low adhesive substrate composed of a fluorinated
polymer (e.g., polytetrafluoroethylene (PTFE),
polychlorotrifluoroethylene, polyvinyl fluoride, polyvinyl idene
fluoride, tetrafluoroethylenehexafluoropropylene copolymer,
chlorofluoroethylenevinylidene fluoride copolymer etc.), (c) a low
adhesive substrate composed of a non-polar polymer (e.g.,
olefin-based resin such as polyethylene, polypropylene and the
like, and the like), (d) conventionally used peel paper (crepe
paper, embossed paper, Japanese paper, fiber paper etc.) and the
like can be used.
[0144] Examples of the substrate for a release liner include
plastic substrates such as polyester film (poly(ethylene
terephthalate) film etc.), olefin-based resin film (polyethylene
(PE) film, polypropylene (PP) film etc.), polyvinyl chloride film,
polyimide film, polyamide film (nylon film), rayon film and the
like, paper (quality paper, Japanese paper, craft paper, glassine,
synthetic paper, top-coat paper and the like), multi-layered
product (composite of 2-3 layers) of these by lamination,
coextrusion and the like and the like.
[0145] When the release liner is laminated on elastomer layer 1, as
a release agent that forms a release-treated layer, a
silicone-based release agent, a fluorinated release agent, a long
chain alkyl-based release agent and the like are used.
[0146] When the release liner is laminated on pressure-sensitive
adhesive layer 3 (particularly polyoxyalkylene-based adhesive
layer), a release agent that forms a release-treated layer is
preferably a fluorosilicone-based release agent, particularly
preferably a fluorosilicone-based release agent cation-polymerized
by UV radiation.
[0147] A release-treated layer is formed by applying a coating
solution obtained by dissolving or dispersing a release agent in an
organic solvent to at least one face of a substrate for a release
liner with a general coating apparatus such as roll coater, reverse
coater, doctor blade coater and the like, and drying same. While
the coating amount (solid content) of the release agent is not
particularly limited, it is generally about 0.05-6 mg/cm.sup.2.
[0148] The thickness (thickness of substrate for release liner,
thickness of low adhesive substrate) of the release liner is
preferably about 0.5-5 mil, more preferably about 2-3 mil. When the
thickness is in such preferable range, the flexibility, handling
workability and the like of the release liner are further improved.
As the release liner, one using PE film, PP film and the like as a
substrate for a release liner, or a low adhesive substrate composed
of PE, PP or PTFE is preferable from the aspect of flexibility.
[0149] (2) Sheet 11 in the second form (sheet having laminate
constitution of elastomer layer 1 having a Shore A hardness of less
than 40/core film 2/elastomer layer 1 having a Shore A hardness of
less than 40) <Elastomer Layer 1 Having a Shore A Hardness of
Less than 40>
[0150] The detail and preferable embodiment and the like of the
constitution materials of elastomer layer 1 follow those of
elastomer layer 1 of the above-mentioned sheet 10 in the first
form.
[0151] To obtain sheet 11 having an elastomer layer 1 having a
Shore A hardness of less than 40 and an adhesion force to stainless
steel of not more than 11 oz/in at 90 degree peel strength, the
thickness of the elastomer layer 1 having a Shore A hardness of
less than 40 is preferably 2-40 mil, more preferably 15-35 mil.
When the thickness of the elastomer layer 1 is within such
preferable range, the maintenance of a wrapped state of a roll
product 53 and handling property as a sheet become more
superior.
<Core Material 2>
[0152] The detail and preferable embodiment and the like of the
constitution materials of core material 2 follow those of core film
2 of the above-mentioned sheet 10 in the first form.
[0153] To obtain sheet 11 in the second form having an elastomer
layer 1 having a Shore A hardness of less than 40 and an adhesion
force to stainless steel of not more than 11 oz/in at 90 degree
peel strength, the thickness of the core material 2 is preferably
0.5-10 mil, more preferably 2-7 mil. When the thickness of the core
material 2 is within such preferable range, the maintenance of a
wrapped state of a roll product and handling efficiency as a tape
are further improved.
[0154] In the sheet 11 in the second form, the thickness of the
whole sheet, that is, the total thickness of elastomer layer 1
having a Shore A hardness of less than 40, core material 2 and
elastomer layer 1 having a Shore A hardness of less than 40 is
preferably 4-90 mil, more preferably 30-80 mil. When the total
thickness is within such preferable range, the maintenance of a
wrapped state of a roll product 53 and handling efficiency and the
like as a sheet are further improved.
<Release Liner 4>
[0155] The detail and preferable embodiment and the like of release
liner 4 follow those of release liner 4 of the above-mentioned
sheet 10 in the first form. [0156] (3) Sheet 12 in the third form
(single layer sheet having only elastomer layer 1 having a Shore A
hardness of less than 40) <Elastomer Layer 1 Having a Shore A
Hardness of Less than 40>
[0157] The detail and preferable embodiment and the like of the
constitution materials of elastomer layer 1 follow those of
elastomer layer 1 of the above-mentioned sheet 10 in the first
form.
[0158] To obtain sheet 12 in the third form having an elastomer
layer 1 having a Shore A hardness of less than 40 and an adhesion
force to stainless steel of not more than 11 oz/in at 90 degree
peel strength, the thickness of the elastomer layer 1 having a
Shore A hardness of less than 40 is preferably 2-40 mil, more
preferably 15-35 mil. When the thickness of the elastomer layer 1
is within such preferable range, the maintenance of a wrapped state
of a roll product 54 and handling property as a sheet become more
superior.
<Release Liner 4>
[0159] The detail and preferable embodiment and the like of release
liner 4 follow those of release liner 4 of the above-mentioned
sheet 10 in the first form. [0160] (4) Sheet 13 in the fourth form
(sheet having laminate constitution of elastomer layer 1 having a
Shore A hardness of less than 40/core material 2/elastomer layer 1
having a Shore A hardness of less than 40/substrate 5)
<Elastomer layer 1 having a Shore A hardness of less than
40>
[0161] The detail and preferable embodiment and the like of the
constitution materials of elastomer layer 1 on the side separating
from substrate and elastomer layer 1 on the side in contact with
substrate 5 follow those of elastomer layer 1 of the
above-mentioned sheet 10 in the first form.
[0162] The thickness of these two elastomer layers 1 is preferably
2-40 mil, more preferably 15-35 mil. When the thickness of the
elastomer layer 1 is within such preferable range, the maintenance
of a wrapped state of a roll product 56 and handling efficiency as
a sheet become further superior.
<Core Material 2>
[0163] The detail and preferable embodiment and the like of the
constitution materials of core material 2 follow those of core
material 2 of the above-mentioned sheet 10 in the first form.
[0164] To obtain sheet 13 in the fourth form having an elastomer
layer 1 having a Shore A hardness of less than 40 and an adhesion
force to stainless steel of not more than 11 oz/in at 90 degree
peel strength, the thickness of the core material 2 is preferably
0.5-10 mil, more preferably 1-3 mil. When the thickness of the core
material 2 is within such preferable range, the maintenance of a
wrapped state of a roll product 55 and handling efficiency as a
sheet become more superior.
<Substrate 5>
[0165] Having substrate 5, adhesion of sheet 14 to an adherend and
peel workability during maintenance can be improved further.
[0166] The material of substrate 5 is not particularly limited.
Examples thereof include a single layer or laminate plastic film
made from one or more kinds selected from polyester (e.g.,
poly(ethylene terephthalate) (PET) and the like); nylon; polyvinyl
chloride; polyvinylidene chloride; polyolefin (e.g., polyethylene,
polypropylene, reactor TPO, ethylene-vinyl acetate copolymer and
the like); fluororesin (e.g., polytetrafluoroethylene (PTFE),
polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride
(PVDF), polyvinyl fluoride (PVF), perfluoroalkoxyfluororesin (PFA),
tetrafluoroethylene hexafluoropropylene copolymer (FEP), ethylene
tetrafluoroethylene copolymer (ETFE), ethylene
chlorotrifluoroethylene copolymer (ECTFE) and the like, a metal
foil, and the like. Also, it may be a film obtained by laminating a
plastic film and a metal foil. A fiber sheet (a single layer sheet,
laminated sheet of two or more layers) such as knitted fabric,
woven fabric, non-woven fabric and the like using one or more kinds
of fibers selected from synthetic polymer fibers such as polyester
(e.g., poly(ethylene terephthalate) (PET) and the like) and the
like, natural fibers such as cotton, hemp and the like, metal fiber
and glass fiber, and a laminated sheet wherein one or more kinds of
such fiber sheets are laminated on the aforementioned plastic film
can also be used as a substrate.
[0167] The thickness of substrate 5 is preferably 0.5-10 mil, more
preferably 2-7 mil. When the thickness of the substrate is within
such preferable range, adhesion of sheet 13 to an adherend and peel
workability during maintenance can be improved further.
[0168] In the sheet 13 in the fourth form, the thickness of the
whole sheet, that is, the total thickness of elastomer layer 1
having a Shore A hardness of less than 40, core material 2,
elastomer layer 1 having a Shore A hardness of less than 40 and
substrate 5 is preferably 5-100 mil, more preferably 30-80 mil.
When the total thickness is within such preferable range, the
maintenance of a wrapped state of a roll product 55 and handling
efficiency and the like as a sheet are further improved.
<Release liner 4>
[0169] The detail and preferable embodiment and the like of release
liner 4 follow those of release liner 4 of the above-mentioned
sheet 10 in the first form. [0170] (6) Sheet 14 in the fifth form
(sheet having laminate constitution of elastomer layer 1 having a
Shore A hardness of less than 40/substrate 5) <Elastomer layer 1
having a Shore A hardness of less than 40>
[0171] The detail and preferable embodiment and the like of the
constitution materials of elastomer layer 1 follow those of
elastomer layer 1 of the above-mentioned sheet 10 in the first
form.
[0172] To obtain sheet 14 in the fifth form having an elastomer
layer 1 having a Shore A hardness of less than 40 and an adhesion
force to stainless steel of not more than 11 oz/in at 90 degree
peel strength, the thickness of the elastomer layer 1 having a
Shore A hardness of less than 40 is preferably 2-40 mil, more
preferably 15-35 mil. When the thickness of the elastomer layer 1
having a Shore A hardness of less than 40 is within such preferable
range, the maintenance of a wrapped state of a roll product 56 and
handling efficiency as a sheet are further improved.
<Substrate 5>
[0173] The detail and preferable embodiment and the like of the
constitution materials of substrate 5 follow those of substrate 5
of the above-mentioned sheet 13 in the fourth form.
[0174] In the sheet 14 in the fifth form, the thickness of the
whole sheet, that is, the total thickness of elastomer layer 1
having a Shore A hardness of less than 40 and substrate 5 is
preferably 2.5-50 mil, more preferably 17-42 mil. When the total
thickness is within such preferable range, the maintenance of a
wrapped state of a roll product 56 and handling efficiency and the
like as a sheet are further improved.
<Release Liner 4>
[0175] The detail and preferable embodiment and the like of release
liner 4 follow those of release liner 4 of the above-mentioned
sheet 10 in the first form.
[0176] The sheet of the present invention does not easily absorb
moisture and has preferable property for achieving moisture-proof
and/or anticorrosion by adhesion to an adherend. That is, the sheet
of the present invention shows a moisture absorption percentage of
not more than 2.5% (preferably not more than 1.0%) as measured
according to ASTM D570.
[Production Method of Sheet]
[0177] The production method of the sheet of the present invention
is not particularly limited and the sheet can be produced, for
example, by the following method. In the following description, the
"step liner" means a liner (sheet, film) used in the production
step, which is not included in the final product (the sheet of the
present invention).
[0178] In the case of a sheet in the first form (FIGS. 1(A) and
1(B)), it is produced via the following first step and second
step.
[0179] First step: An elastomer layer 1 is formed on a core
material 2 by coating, and a release liner 4 (at least one face is
release-treated) is laminated thereon.
[0180] Second step: A pressure-sensitive adhesive layer 3 is formed
on a step liner by coating, and the pressure-sensitive adhesive
layer 3 is laminated on the back face of the core material 2 that
went through the first step.
[0181] The press condition for lamination is preferably about 5-7
kgf/cm.sup.2. Thereafter, one of the release liners (step liner) is
peeled off, and the sheet is wound up in a roll such that the
forming face of the pressure-sensitive adhesive layer 3 contacts
the release-treated face of at least one face and the other release
liner 4, that is, pressure-sensitive adhesive layer 3 being the
inside, and the elastomer layer 1 and the release liner 4 being the
outside.
[0182] In the case of a sheet in the first form (FIGS. 2(A) and
2(B)), it is produced via the following first step and second
step.
[0183] First step: An elastomer layer 1 is formed on a core 2 by
coating, and a step liner is laminated on elastomer layer 1 as
necessary.
[0184] Second step: A pressure-sensitive adhesive layer 3 is formed
on a release liner 4 (at least one face is release-treated), the
pressure-sensitive adhesive layer 3 is laminated on the back face
of the core material 2 that went through the first step, the step
liner is peeled off as necessary, and the sheet is rolled up.
[0185] The press condition for lamination is preferably about 5-7
kgf/cm.sup.2. Thereafter, one of the release liners (step liner) is
peeled off, and the sheet is wound up in a roll with single face on
the opposite side from the forming face of the pressure-sensitive
adhesive layer 3 of the other release liner 4 being the outside
face and the elastomer layer 1 being the inside face.
[0186] In the case of a sheet 11 in the second form (FIGS. 3(A) and
3(B)), it is produced via the following first step and second
step.
[0187] First step: An elastomer layer 1 is formed by coating on a
core 2 by coating, and a step liner is adhered.
[0188] Second step: The elastomer layer 1 is coated on the back
face of the core 2 that went through the first step, a release
liner 4 (at least one face is release-treated, and double faces
have different peel forces) is adhered, the step liner is peeled
off, and the sheet is rolled up.
[0189] The press condition for lamination is preferably about 5-7
kgf/cm.sup.2. Thereafter, one of the release liners is peeled off,
and the sheet is wound up in a roll with a single face of the other
release liner on the opposite side from the forming face of the
elastomer layer 1 having a Shore A hardness of less than 40 being
the outside face.
[0190] In the case of a sheet 12 in the third form (FIGS. 4(A) and
4(B)), an elastomer layer 1 having a Shore A hardness of less than
40 is formed on a single face of a release liner (double faces are
release-treated), and the sheet is wound up in a roll with the
single face of the release liner on the opposite side from the
forming face of the elastomer layer 1 having a Shore A hardness of
less than 40 being the outside face.
[0191] In the case of a sheet 13 in the fourth form (FIGS. 5(A) and
5(B)), a release liner is prepared, an elastomer layer 1 having a
Shore A hardness of less than 40 is formed on a single face of the
release liner, and a core 2 is adhered to the elastomer layer 1.
Then, an elastomer layer 1 having a Shore A hardness of less than
40 is formed on one single face (single face without release
treatment, or single face after adhesion improving treatment in the
case of low adhesive substrate) of substrate 5 that went through a
release-treatment of the other single face (back face), and the
elastomer layer 1 having a Shore A hardness of less than 40 is
press laminated on the single face of core 2. The press condition
therefor is preferably about 5-7 kgf/cm.sup.2. Thereafter, the
release liner is peeled off, and the sheet is wound up in a roll
with the release-treated single face of the substrate 5 being the
outside face.
[0192] In the case of a sheet 14 in the fifth form (FIGS. 6(A) and
6(B)), an elastomer layer 1 having a Shore A hardness of less than
40 is formed on one single face (single face without release
treatment, or single face after adhesion improving treatment in the
case of low adhesive substrate) of substrate 5 that went through a
release-treatment of the other single face (back face), and the
sheet is wound up in a roll with the release-treated single face of
the substrate 4 being the outside face.
[0193] The present invention is explained in more detail in the
following by referring to Examples and Comparative Examples, which
are not to be construed as limitative.
[0194] The property measurement test and property evaluation in the
Examples and Comparative Examples are as follows. [0195] 1. Shore A
hardness
[0196] The aforementioned method. [0197] 2. 90 degree peel
strength
[0198] The aforementioned method. [0199] 3. Moisture absorption
percentage
[0200] According to ASTM D570. That is, a sheet is cut into a 10
inch length.times.1 inch width and the sample was adhered to an
aluminum board. The board is stood at room temperature for 24 hr
and the weight was measured (initial value). The sample is
preserved in a chamber at 49.degree. C., humidity 95% for 7 days.
After completion of the preservation, water drops on the surface
are removed with dried gauze and the weight was measured (final
value). The percentage of difference between the final value and
the initial value relative to thus-measured initial value is taken
as a moisture absorption percentage. The moisture absorption
percentage was determined for 5 samples, and the average thereof
was taken as an evaluation value. [0201] 4. Corrosion resistance
test (adhesion evaluation test)
[0202] A sheet is cut into a 3 inch.times.3 inch flat plane size,
and adhered to a 4 inch.times.4 inch (flat plane size) aluminum
panel. After one reciprocation with a 2 kg roller, the sheet is
aged for 24 hr at ambient temperature to give a test sample. The
sample was subjected to a salt water spray test under the following
conditions.
[0203] salt water spray test (according to ASTM B117)
[0204] sample set angle: 30.degree.
[0205] temperature: 35+1.1-1.7.degree. C.
[0206] salt water concentration: 5 wt %
[0207] spray amount: 1.5 ml/80 cm.sup.2/hr
[0208] test time: 250 hr, 500 hr [0209] Seal performance
evaluation: After the test, the sheet is detached from the aluminum
panel, and the ratio of the corroded area to the whole area of the
region, to which the sheet has been adhered, is determined. When a
corroded part is not less than 1%, the sheet is evaluated as
disqualified, and when the corroded part is less than 1%, the sheet
is evaluated as qualified. The corrosion was determined by visual
observation. [0210] 5. Removability test
[0211] To the top face (after peeling release liner) of a sample
similar to that in the corrosion resistance test is pressed the
same size of an aluminum panel to prepare a sandwich-shaped test
sample. The test sample is aged for 24 hr at room temperature,
heated in an oven at 70.degree. C. for 48 hr, taken out and the
panel is peeled off 30 min later. The evaluation criteria are as
follows.
[0212] Good: Sheet can be peeled off easily with hand without using
special tool or method. No adhesive residue after peeling the sheet
from the panel.
[0213] Acceptable: Peeling off from the panel only with hand is
difficult and can be peeled off only by expanding the gap with a
screwdriver and the like. No adhesive residue after peeling the
sheet from the panel.
[0214] Bad: Peeling off from the panel only with hand is difficult
and can be peeled off only by expanding the gap with a screwdriver
and the like. Adhesive residue is present after peeling the sheet
from the panel.
Examples 1-3, Comparative Examples 1-4
(Materials Used)
[0215] 1. Elastomer composition
[0216] SILBIONE LSR 6301 A/B manufactured by Bluestar Silicones,
A:B=100:100 (parts by weight)
[0217] SILBIONE LSR 6305 A/B manufactured by Bluestar Silicones,
A:B=100:100 (parts by weight)
[0218] LR 3003/30 A/B manufactured by ELASTOSIL, A:B=100:100 (parts
by weight)
[0219] KE1100 A/B manufactured by Shin-Etsu Silicone, A:B=100:100
(parts by weight)
[0220] SE4400 A/B manufactured by Dow Corning Toray, A:B=100:100
(parts by weight)
[0221] Note 1) All elastomer compositions were of two-component
curing type, and equal amounts of component A and component B were
blended. [0222] 2. Pressure-sensitive adhesive [0223]
(Polyoxyalkylene-based adhesive)
[0224] base compound: SILYL ACX022*.sup.1 manufactured by KANEKA,
100 parts by weight
[0225] flame retardant 1: FRCROS486*.sup.2 manufactured by
BUDENHEIM, 50 parts by weight
[0226] flame retardant 2: TCP*.sup.3 manufactured by Rit-Chem, 30
parts by weight
[0227] tackifier: PENSEL D-125*.sup.4 manufactured by Arakawa
Chemical Industries, 20 parts by weight
[0228] crosslinking agent: SILYL CR500*.sup.5 manufactured by
KANEKA, 7.65 parts by weight
[0229] catalyst: PT-56003P (3% Pt-VTS-IPA Solution)*.sup.6
manufactured by AB Specialty Silicones, 0.1 part by weight
[0230] reaction control agent: 3-Methyl-l-butyn-3-ol manufactured
by TCI America, 0.05 parts by weight
[0231] *1) terminal allylated polyoxypropylene wherein an allyl
group is bonded to both terminals of polypropyleneglycol having an
average molecular weight of about 28000
[0232] *2) silane-coated product of ammonium polyphosphate
[0233] *3) tricresyl phosphate
[0234] *4) rosin ester resin
[0235] *5) hydrogen siloxane-based compound having 5 hydrosilyl
groups on average in a molecule
[0236] *6) isopropanol-diluted liquid of
divinyltetramethyldisiloxane platinum complex
(Polyurethane-Based Adhesive)
[0237] Hi-TAK HT3935 manufactured by AV-DEC [0175] [0238] 3. PTFE
film
[0239] thickness 5 mil, double face Na etching treatment [0176]
[0240] 4. Preparation of sheets
Examples 1-3, Comparative Examples 1, 2
[0240] [0241] (1) An elastomer composition was applied to one of
the single faces of PTFE film, dried in an oven at 130.degree. C.
for 3 min (thickness after drying 30 mil), and a release liner (S2
CL PET 5100/5100 manufactured by Loparex) was laminated with a hand
roller. [0242] (2) A pressure-sensitive adhesive was applied to a
single face of the same another release liner, dried in an oven at
130.degree. C. for 3 min (thickness after drying 20 mil), and the
obtained pressure-sensitive adhesive layer was laminated on the
other single face of the PTFE film of (1) with a hand roller.
Comparative Examples 3, 4
[0243] The elastomer composition in the above-mentioned (1) was
changed to polyoxyalkylene-based adhesive or polyurethane-based
adhesive, and the above-mentioned (1) and (2) were performed.
[0244] The test results are shown in Table 1.
TABLE-US-00001 TABLE 1 Comparative Comparative Comparative
Comparative Example 1 Example 2 Example 3 Ex 1 Ex 2 Ex 3 Ex 4 1st
layer Material LSR 6301 SR 6305 LS 3003/30 KE-1100 SE 4400 Poly-
Poly- oxyalkylen urethane Shore A Hardness 1 5 30 40 78 -- --
Thickness 30 30 30 30 30 20 -- [mil] Core film Material PTFE PTFE
PTFE PTFE PTFE PTFE Mesh Thickness 5 5 5 5 5 5 -- [mil] 2nd layer
Material Poly- Poly- Poly- Poly- Poly- Poly- Poly- oxyalkylen
oxyalkylen oxyalkylen oxyalkylen oxyalkylen oxyalkylen urethane
Thickness 20 20 20 20 20 20 -- [mil] Total Thickness 55 55 55 55 55
45 45 [mil] Adhesion (1st layer) 2.31 2.26 1.28 0.94 0.81 8.86
11.02 [oz/in] Moisture Absorption 0.19 0.22 0.32 0.02 0.20 1.00
0.14 [%] 250 hr Salt Spray PASS PASS PASS FAIL FAIL PASS PASS 500
hr Salt Spray PASS PASS PASS -- -- PASS PASS Removability Good Good
Good Good Good Acceptable Bad
* * * * *