U.S. patent application number 14/412966 was filed with the patent office on 2015-07-02 for adhesive layer and adhesive sheet.
This patent application is currently assigned to DAI NIPPON PRINTING CO., LTD. The applicant listed for this patent is DAI NIPPON PRINTING CO., LTD.. Invention is credited to Kentaro Hoshi, Takahisa Taniguchi.
Application Number | 20150184034 14/412966 |
Document ID | / |
Family ID | 49882092 |
Filed Date | 2015-07-02 |
United States Patent
Application |
20150184034 |
Kind Code |
A1 |
Taniguchi; Takahisa ; et
al. |
July 2, 2015 |
ADHESIVE LAYER AND ADHESIVE SHEET
Abstract
There are provided a pressure-sensitive or bonding adhesive
layer that, when a repairing or reinforcing sheet is laminated onto
concrete, can temporarily fix the sheet to the concrete to
facilitate the repair or reinforcement of the concrete, and a
pressure-sensitive or bonding adhesive sheet that includes the
pressure-sensitive or bonding adhesive layer. The
pressure-sensitive or bonding adhesive layer contains an acrylic
resin having a glass transition temperature of 15.degree. C. or
below and further contains a liquid epoxy resin, a solid epoxy
resin, and a curing agent. A pressure-sensitive or bonding adhesive
sheet includes a pressure-sensitive or bonding adhesive layer and a
separation film or a repairing or reinforcing sheet provided on one
surface of the pressure-sensitive or bonding adhesive layer.
Inventors: |
Taniguchi; Takahisa;
(Tokyo-to, JP) ; Hoshi; Kentaro; (Tokyo-to,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAI NIPPON PRINTING CO., LTD. |
Tokyo-to |
|
JP |
|
|
Assignee: |
DAI NIPPON PRINTING CO.,
LTD
Tokyo-to
JP
|
Family ID: |
49882092 |
Appl. No.: |
14/412966 |
Filed: |
July 4, 2013 |
PCT Filed: |
July 4, 2013 |
PCT NO: |
PCT/JP2013/068402 |
371 Date: |
January 5, 2015 |
Current U.S.
Class: |
428/41.5 ;
525/92H |
Current CPC
Class: |
B32B 7/12 20130101; C08G
59/50 20130101; E04G 23/02 20130101; B32B 2307/712 20130101; C09J
133/08 20130101; B32B 27/00 20130101; C08L 63/00 20130101; B32B
7/06 20130101; B32B 13/00 20130101; B32B 27/308 20130101; C09J
2301/302 20200801; B32B 27/06 20130101; B32B 27/08 20130101; C09J
7/20 20180101; B32B 27/30 20130101; B32B 2307/762 20130101; C08L
33/06 20130101; C09J 7/10 20180101; C09J 7/387 20180101; B32B
2405/00 20130101; B32B 27/26 20130101; C09J 2463/00 20130101; B32B
27/38 20130101; C08G 59/4021 20130101; B32B 2419/00 20130101; C09J
7/38 20180101; Y10T 428/1462 20150115; E04G 23/04 20130101; C09J
163/00 20130101; C09J 2433/00 20130101; B32B 2307/756 20130101;
B32B 7/00 20130101; B32B 13/04 20130101; C08L 63/00 20130101; C08L
33/06 20130101; C09J 163/00 20130101; C08L 33/06 20130101; C09J
2433/00 20130101; C09J 2463/00 20130101; C09J 163/00 20130101; C08L
33/06 20130101; C08L 63/00 20130101 |
International
Class: |
C09J 7/02 20060101
C09J007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 4, 2012 |
JP |
2012-150913 |
Sep 7, 2012 |
JP |
2012-197367 |
Jun 6, 2013 |
JP |
2013-120254 |
Claims
1. A pressure-sensitive or bonding adhesive layer comprising: an
acrylic resin having a glass transition temperature of 15.degree.
C. or below; a liquid epoxy resin; a solid epoxy resin; and a
curing agent configured to cure the liquid epoxy resin and the
solid epoxy resin.
2. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein a pressure sensitive adhesive strength of the
layer is greater than or equal to 0.4N/25 mm and less than or equal
to 5N/25 mm.
3. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the content of the acrylic resin is greater than
or equal to 4% by mass and less than or equal to 50% by mass based
on the total amount of the acrylic resin, the liquid epoxy resin
and the solid epoxy resin.
4. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the content of the liquid epoxy resin is greater
than or equal to 20% by mass and less than or equal to 80% by mass
based on the total amount of the liquid epoxy resin and the solid
epoxy resin.
5. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the liquid epoxy resin and the solid epoxy resin
include at least one selected from the group of a bisphenol A epoxy
resin and a bisphenol F epoxy resin.
6. A pressure-sensitive or bonding adhesive sheet comprising: the
pressure-sensitive or bonding adhesive layer according to claim 1;
and a first separation film provided to a first surface of the
layer.
7. The pressure-sensitive or bonding adhesive sheet according to
claim 6, further comprising a second separation film provided to a
second surface of the layer.
8. A pressure-sensitive or bonding adhesive sheet comprising: the
pressure-sensitive or bonding adhesive layer according to claim 1;
and a repairing or reinforcing sheet provided to a first surface of
the layer.
9. The pressure-sensitive or bonding adhesive sheet according to
claim 8, further comprising a separation film provided to a second
surface of the layer.
10. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the acrylic resin includes copolymers of
methacrylate-acrylate-methacrylate.
11. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the acrylic resin has a mass average molecular
weight in the range of 150,000 to 1,500,000.
12. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the liquid epoxy resin has a mass average
molecular weight in the range of 300 to 2,000 and an epoxy
equivalent of 100 to 800.
13. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the solid epoxy resin has a mass average molecular
weight in the range of 300 to 5,000 and an epoxy equivalent of 100
to 2,200.
14. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the curing agent is a latent curing agent.
15. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the curing agent includes a combination of a
photobase generator curing catalyst and either a mercapto
group-containing curing agent or a phenolic hydroxyl
group-containing curing agent.
16. The pressure-sensitive or bonding adhesive layer according to
claim 1, wherein the layer has a thickness greater than or equal to
150 .mu.m and less than or equal to 500 .mu.m.
17. The pressure-sensitive or bonding adhesive layer according to
claim 8, wherein the repairing or reinforcing sheet includes a
fiber material.
18. A pressure-sensitive or bonding adhesive sheet comprising: a
first pressure-sensitive or bonding adhesive layer according to
claim 1 having a first surface; a second pressure-sensitive or
bonding adhesive layer according to claim 1 having a first surface;
and a repairing or reinforcing sheet disposed between the first and
second pressure-sensitive or bonding adhesive layers so as to
contact the first surface of the first pressure-sensitive or
bonding adhesive layer and the first surface of the second
pressure-sensitive or bonding adhesive layer.
19. A repairing or reinforcement method comprising: providing the
pressure-sensitive or bonding adhesive layer according to claim 1;
applying the layer to an adherend; and curing the layer such that
the layer is bonded to the adherend.
20. The repairing or reinforcement method according to claim 19,
wherein the curing of the layer is accomplished by heat or by
irradiation of ultraviolet light or electron beams.
Description
TECHNICAL FIELD
[0001] The present invention relates to a pressure-sensitive or
bonding adhesive layer for use in the application of a repairing or
reinforcing sheet to concrete, and a pressure-sensitive or bonding
adhesive sheet having the pressure-sensitive or bonding adhesive
layer.
BACKGROUND ART
[0002] In recent years, repair and reinforcement of concrete have
been carried out according to need from the viewpoints of
durability and safety of concrete (also called a concrete
structure). The repair and reinforcement of the concrete have been
usually carried out by recoating an adhesive, a coating material or
the like a plurality of times onto a portion that should be
repaired or reinforced, or by bonding a sheet for repair or
reinforcement purposes. The repairing or reinforcing sheet is
preferably used from the viewpoints of preventing concrete
deterioration factors such as water, oxygen, carbon dioxide, or
chloride ions from entering the concrete and, at the same time,
reinforcing concrete that, due to a deterioration, has a lowered
strength. Various proposals have hitherto been made on techniques
for concrete repair or reinforcement.
[0003] Japanese Patent Application Laid-Open No. 144360/2010
proposes a technique for a concrete repairing method that includes
applying a concrete repairing sheet to a surface of concrete to be
repaired with an adhesive for construction, the concrete repairing
sheet including an intermediate layer having a resin film and a
surface layer formed of a woven fabric material stacked on both
sides of the intermediate layer through an adhesive resin, and then
coating a coating material on the surface layer of the concrete
repairing sheet remote from the surface which has been applied to
the concrete. The claimed advantage of this technique is that,
since the surface layer that comes into contact with the concrete
surface is formed of a woven fabric material having a large surface
area, even when the concrete surface is a vertical surface or a
ceiling surface, the concrete repairing sheet is less likely to be
dropped or separated before complete curing of the adhesive for
construction and, further, the quality of the construction is high.
Further, since the adhesive for construction is completely shielded
from the coating material through the concrete repairing sheet,
there is no need to wait for curing of the adhesive for
construction for coating of the coating material, contributing to a
shortened construction time.
[0004] Japanese Patent Application Laid-Open No. 27718/2004
proposes a technique for a repairing, reinforcing, or deterioration
preventive sheet for concrete structures, the sheet including a
protective layer and an adhesive coating layer bonded to each
other, and an adhesive layer of a pressure-sensitive adhesive or a
hot-melt adhesive provided on the adhesive coating layer on its
surface to be bonded to concrete structures. This technique is
advantageous in that a reduction in repairing or reinforcing work
for preventing peeling-off of concrete, shortening of a time
necessary for the repairing or reinforcing work, and the
stabilization of the quality can be realized by applying the
repairing, reinforcing, or deterioration preventive sheet to a
portion to be repaired on site.
PRIOR ART DOCUMENTS
Patent Documents
[0005] Patent Document 1: Japanese Patent Application Laid-Open No.
144360/2010
[0006] Patent Document 2: Japanese Patent Application Laid-Open No.
27718/2004
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0007] The technique proposed in Japanese Patent Application
Laid-Open No. 144360/2010 suffers from a problem of poor
workability due to the fact that, in repairing work of concrete,
the adhesive for construction is coated onto the concrete or the
concrete repairing sheet. Further, in the technique, since the
coverage of the adhesive for construction cannot be even, the
reproducibility of the repairing work is disadvantageously
lowered.
[0008] In the technique proposed in Japanese Patent Application
Laid-Open No. 27718/2004, since the adhesive layer is formed of a
pressure-sensitive adhesive or a hot-melt adhesive, for example,
when the adhesive layer is formed of a pressure-sensitive adhesive,
the adhesion is disadvantageously unsatisfactory. On the other
hand, when the adhesive layer is formed of a hot-melt adhesive,
since the adhesive is softened by heating in bonding, difficulties
are encountered in bonding the sheet to a concrete surface that is
a vertical surface or a ceiling surface.
[0009] The present invention has been made in view of the problems
involved in the prior art, and an object of the present invention
is to provide a pressure-sensitive or bonding adhesive layer that,
in applying a repairing or reinforcing sheet to an adherend such as
concrete, can temporarily fix the sheet to the adherend and the
repair or reinforcement of the adherend can easily be carried out,
and a pressure-sensitive or bonding adhesive sheet having the
pressure-sensitive or bonding adhesive layer.
Means for Solving the Problems
[0010] According to one aspect of the present invention, there is
provided a pressure-sensitive or bonding adhesive layer comprising
an acrylic resin having a glass transition temperature of
15.degree. C. or below and further comprising a liquid epoxy
resins, a solid epoxy resin, and a curing agent.
[0011] In a preferred embodiment of the present invention, the
pressure-sensitive or bonding adhesive layer is used for
pressure-sensitive bonding of a repairing or reinforcing sheet to
concrete.
[0012] In a preferred embodiment of the present invention, the
content of the acrylic resin is 4% by mass to 50% by mass based on
the total amount of the acrylic resin, the liquid epoxy resin and
the solid epoxy resin.
[0013] In a preferred embodiment of the present invention, the
content of the liquid epoxy resin is 20% by mass to 80% by mass
based on the total amount of the liquid epoxy resin and the solid
epoxy resin.
[0014] In a preferred embodiment of the present invention, the
liquid epoxy resin and the solid epoxy resin are bisphenol A epoxy
resins.
[0015] According to another aspect of the present invention, there
is provided a pressure-sensitive or bonding adhesive sheet
comprising: a pressure-sensitive or bonding adhesive layer; and a
separation film provided on one surface of the pressure-sensitive
or bonding adhesive layer.
[0016] In an embodiment of the present invention, another
separation film may be provided on a surface of the
pressure-sensitive or bonding adhesive layer on which the
separation film is not provided.
[0017] According to a further aspect of the present invention,
there is provided a pressure-sensitive or bonding adhesive sheet
comprising: a pressure-sensitive or bonding adhesive layer; and a
repairing or reinforcing sheet provided on one surface of the
pressure-sensitive or bonding adhesive layer.
[0018] In an embodiment of the present invention, another
separation film is provided on a surface of the pressure-sensitive
or bonding adhesive layer on which the repairing or reinforcing
sheet is not provided.
Effect of the Invention
[0019] According to the present invention, in applying a repairing
or reinforcing sheet to adherends such as concrete, the repairing
or reinforcing sheet can be temporarily fixed to the adherends by
virtue of pressure-sensitive or bonding adhesive properties and
bonding properties possessed by a pressure-sensitive or bonding
adhesive layer, and, thus, the repair or reinforcement of adherends
can easily be carried out.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a typical cross-sectional view of an example of a
pressure-sensitive or bonding adhesive layer according to the
present invention (FIG. 1A) and examples of a pressure-sensitive or
bonding adhesive sheet including a pressure-sensitive or bonding
adhesive layer and a separation film (FIGS. 1B and 1C).
[0021] FIG. 2 is a typical cross-sectional view of an example of a
pressure-sensitive or bonding adhesive sheet including a
pressure-sensitive or bonding adhesive layer according to the
present invention and a repairing or reinforcing sheet.
[0022] FIG. 3 is a typical cross-sectional view of another example
of a pressure-sensitive or bonding adhesive sheet including a
pressure-sensitive or bonding adhesive layer according to the
present invention and a repairing or reinforcing sheet.
MODE FOR CARRYING OUT THE INVENTION
[0023] Embodiments of the pressure-sensitive or bonding adhesive
layer and the pressure-sensitive or bonding adhesive sheet
according to the present invention will be described in more
detail. However, it should be noted that the present invention is
not limited to the following embodiments, and various modifications
are possible within the scope of the subject matter of the present
invention.
[0024] A pressure-sensitive or bonding adhesive layer 2 according
to the present invention contains an acrylic resin having a glass
transition temperature of 15.degree. C. or below and further
contains a liquid epoxy resin, a solid epoxy resin, and a curing
agent. As shown in FIG. 1A, the pressure-sensitive or bonding
adhesive layer 2 per se constitutes the present invention, and,
further, as shown in FIGS. 1B and 1C, FIG. 2, and FIG. 3, the
pressure-sensitive or bonding adhesive sheet 10 (10A to 10G)
including the pressure-sensitive or bonding adhesive layer 2 as
well constitutes the present invention. In the pressure-sensitive
or bonding adhesive layer 2 and the pressure-sensitive or bonding
adhesive sheet 10 including the pressure-sensitive or bonding
adhesive layer 2, when the repairing or reinforcing sheet is
applied to an adherend such as concrete through the
pressure-sensitive or bonding adhesive layer 2, the repairing or
reinforcing sheet can be temporarily fixed to the adherend through
the pressure-sensitive or bonding adhesive layer 2, thereby
facilitating the repair or reinforcement of the adherend,
[0025] Constituent elements of the pressure-sensitive or bonding
adhesive layer 2 and the pressure-sensitive or bonding adhesive
sheet 10 will be described in more detail. Adherends to be applied
to the repairing or reinforcing sheet are preferably concrete.
Further, other adherends to be repaired or reinforced, for example,
mortar or fiber reinforced cement may also be possible. In the
following description, concrete is used as the adherend.
[0026] [Pressure-Sensitive or Bonding Adhesive Layer]
[0027] The pressure-sensitive or bonding adhesive layer 2 contains
an acrylic resin having a glass transition temperature of
15.degree. C. or below and further contains a liquid epoxy resin, a
solid epoxy resin, and a curing agent. The pressure-sensitive or
bonding adhesive layer 2 containing the resin component has a
pressure-sensitive or bonding adhesive force suitable for
temporarily fixing the repairing or reinforcing sheet. As a result,
the repairing or reinforcing sheet can be temporarily fixed to
concrete through the pressure-sensitive or bonding adhesive layer
2. Further, since the pressure-sensitive or bonding adhesive layer
2 has pressure-sensitive or bonding adhesive properties suitable
for temporal bonding, after temporal fixation of the repairing or
reinforcing sheet to concrete through the pressure-sensitive or
bonding adhesive layer 2, the sheet can be separated and again
fixed. Furthermore, bonding properties can be imparted to the
pressure-sensitive or bonding adhesive layer 2 by subjecting the
pressure-sensitive or bonding adhesive layer 2 containing the resin
component to heating, ultraviolet irradiation or other treatment,
and, thus, the temporarily fixed repairing or reinforcing sheet as
such can be strongly bonded to the concrete through the
pressure-sensitive or bonding adhesive layer 2. Further, since the
pressure-sensitive or bonding adhesive layer 2 has
pressure-sensitive or bonding adhesive properties and bonding
properties, even when the concrete surface is a vertical surface or
a ceiling surface, the repairing or reinforcing sheet can be
temporarily fixed or fixed through the pressure-sensitive or
bonding adhesive layer 2.
[0028] The pressure-sensitive or bonding adhesive layer 2 is
applied so that one surface thereof is bonded by pressure-sensitive
bonding to concrete while a repairing or reinforcing sheet is
applied to the other surface. The temporary fixation or the
fixation may be temporary fixation or fixation of the
pressure-sensitive or bonding adhesive layer 2 to concrete or may
be temporary fixation or fixation of a repairing or reinforcing
sheet to the pressure-sensitive or bonding adhesive layer 2. In the
present application, the "pressure-sensitive or bonding adhesion"
means the possession of both pressure-sensitive adhesive properties
and bonding properties, and the pressure-sensitive adhesion means a
temporary bonding phenomenon and is sometimes distinguished from
bonding that means a permanent bonding phenomenon (Physicochemical
Dictionary, 5th version, Iwanami Shoten). The pressure-sensitive or
bonding adhesive layer 2 in an applied form is in a
pressure-sensitive bonded state. Therefore, the pressure-sensitive
or bonding adhesive layer 2 after the application is cured, for
example, by heating or ultraviolet light irradiation to convert the
pressure-sensitive or bonding adhesive layer 2 to a bonded state.
At that time, for example, heating, ultraviolet irradiation, or
electron beam irradiation may be mentioned as a method that cures
the pressure-sensitive or bonding adhesive layer 2 for bonding.
These curing methods are sometimes called "heating or the
like."
[0029] The pressure-sensitive or bonding adhesive layer 2 is a
layer or sheet formed using a composition for pressure-sensitive or
bonding adhesive layer formation. As with a pressure-sensitive or
bonding adhesive sheet 10 that will be described later, the
pressure-sensitive or bonding adhesive layer 2 is generally
provided on a separation film 1, and, after the application of the
pressure-sensitive or bonding adhesive layer 2 to concrete or after
the application of the repairing or reinforcing sheet 3 to the
pressure-sensitive or bonding adhesive layer 2, the separation film
1 is separated for use. The composition for pressure-sensitive or
bonding adhesive layer formation is a resin composition that forms
the pressure-sensitive or bonding adhesive layer 2, for example, by
coating.
[0030] (Acrylic Resin)
[0031] The acrylic resin functions to impart a practicable
pressure-sensitive adhesive strength to the pressure-sensitive or
bonding adhesive layer 2 and to improve coatability and film
forming properties in the formation of the pressure-sensitive or
bonding adhesive layer 2. The acrylic resin is not particularly
limited as long as the glass transition temperature is 15.degree.
C. or below, and, for example, acrylic ester copolymers having a
glass transition temperature of 15.degree. C. or below may be used
as the acrylic resin. Examples of comonomers of the acrylic ester
copolymer having a glass transition temperature of 15.degree. C. or
below include acrylic ester monomers such as methyl acrylate, ethyl
acrylate, propyl acrylate, isopropyl acrylate, isobutyl acrylate,
n-hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, and lauryl
acrylate; functional group-containing monomers such as maleic acid,
itaconic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
acrylamide, N-methylol acrylamide, n-butoxy-N-methylol acrylamide,
sodium 2-acrylamide-2-methyl-1-propanesulfonate, diacetone
acrylamide, and glycidyl acrylate; and monomers such as styrene,
vinyltoluene, vinyl acetate, acrylonitrile, vinyl chloride,
vinylidene chloride, and ethyl vinyl ether. The acryic ester
copolymer is a copolymer of these comonomers.
[0032] Among these monomer components, acrylic ester copolymers,
comonomers of which are compounds having an epoxy, hydroxyl,
carboxyl, or nitrile group as a functional group, are preferred.
The acrylic ester copolymer can improve the adhesive strength to
concrete. Specific examples thereof include ethyl acrylate-butyl
acrylate-acrylonitrile copolymer, ethyl acrylate-acrylonitrile
copolymer, and butyl acrylate-acrylonitrile copolymer. In the
present application, "acrylic acids" such as methyl acrylate and
ethyl acrylate include "methacrylic acids" such as methyl
methacrylate and ethyl methacrylate.
[0033] Preferred acrylic ester copolymers are block copolymers.
Among them, triblock copolymers of
methacrylate-acrylate-methacrylate are preferred. Block copolymers
are preferred from the viewpoints of imparting a practical strength
of adhesion to concrete and improving the heat resistance of the
pressure-sensitive or bonding adhesive layer 2. Examples of
methacrylates constituting the triblock copolymer include methyl
methacrylate, ethyl methacrylate, propyl methacrylate, butyl
methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate,
cyclohexyl methacrylate, and benzydyl methacrylate. Examples of
acrylates constituting the triblock copolymer include methyl
acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, lauryl
acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and benzydyl
acrylate. Specific examples of triblock copolymers of
methacrylate-acrylate-methacrylate include methyl
methacrylate-butyl acrylate-methyl methacrylate triblock
copolymers.
[0034] The acrylic resin having a glass transition temperature of
15.degree. C. or below can impart practicable pressure-sensitive
adhesive properties to the pressure-sensitive or bonding adhesive
layer 2. The lower limit of the glass transition temperature of the
acrylic resin is not particularly limited. Preferably, however, the
glass transition temperature is in the range of -45.degree. C. to
15.degree. C. from the viewpoint of imparting a practical strength
of adhesion. When the glass transition temperature is above
15.degree. C., there is a possibility that practical
pressure-sensitive adhesive properties cannot be developed.
Practical or practicable pressure-sensitive adhesive properties
mean that the adhesive strength (N125 mm) as determined by the
adhesive strength measurement carried out in working examples that
will be described later is approximately not less than 0.4 N125 mm
and not more than 5 N/25 mm, preferably not more than 4 N/25 mm.
The glass transition temperature can be measured, for example, by a
dynamic viscoelasticity measurement method according to JIS K
7244-1 with a solid viscoelasticity analyzer (manufactured by T.A.
Instruments, model: RSA-III). The glass transition temperature is
expressed in Tg (.degree. C.).
[0035] The mass average molecular weight (Mw) of the acrylic resin
is preferably in the range of 150000 to 1500000, more preferably
400000 to 1200000. The use of the acrylic resin having a mass
average molecular weight (Mw) in this range is advantageous in that
the initial adhesive strength of the pressure-sensitive or bonding
adhesive layer 2 can easily be regulated and, at the same time, the
aggregation force of the pressure-sensitive or bonding adhesive
layer 2 can be enhanced. The mass average molecular weight is a
value as determined using polystyrene as a standard by gel
permeation chromatography (GPC).
[0036] The content of the acrylic resin is preferably 4% by mass to
50% by mass based on the total content of the acrylic resin, the
liquid epoxy resin, and the solid epoxy resin. When the content is
in the above-defined range, a pressure-sensitive adhesive strength
suitable for practical use and a high adhesive strength can be
imparted to the pressure-sensitive or bonding adhesive layer 2.
When the content of the acrylic resin is less than 4% by mass, the
pressure-sensitive adhesive strength of the pressure-sensitive or
bonding adhesive layer 2 is lowered. As a result, in some cases,
the pressure-sensitive or bonding adhesive layer 2 cannot be
applied to concrete, or a repairing or reinforcing sheet cannot be
applied to the pressure-sensitive or bonding adhesive layer 2.
Further, in some cases, the coatability and the film formability of
the composition for pressure-sensitive or bonding adhesive layer 2
formation is lowered, making it impossible to form the
pressure-sensitive or bonding adhesive layer 2. On the other hand,
when the content of the acrylic resin is more than 50% by mass, the
adhesive strength of the pressure-sensitive or bonding adhesive
layer 2 after curing through heating, ultraviolet light irradiation
or the like is sometimes lowered. The content of the acrylic resin
is preferably 5% by mass to 34% by mass.
[0037] As described above, the pressure-sensitive or bonding
adhesive layer 2 contains an acrylic resin having a glass
transition temperature of 15.degree. C. or below and thus exhibits,
for example, a pressure-sensitive adhesive strength in a range
suitable for practical use, that is, 0.4 N/25 mm to 5 N/25 mm.
Therefore, for example, even when the concrete surface is a
vertical surface or a ceiling surface, a method can be adopted in
which a pressure-sensitive or bonding adhesive layer 2 is applied
and, further, a repairing or reinforcing sheet is applied through
the pressure-sensitive or bonding adhesive layer 2. Further, the
once applied pressure-sensitive or bonding adhesive layer 2 can be
separated and again applied, and, furthermore, the repairing or
reinforcing sheet applied through the pressure-sensitive or bonding
adhesive layer 2 can be separated and again applied.
[0038] The acrylic resin contained in the pressure-sensitive or
bonding adhesive layer 2 functions to lower the concentration of
the liquid epoxy resin and the solid epoxy resin in the
pressure-sensitive or bonding adhesive layer 2. As a result, since
the acrylic resin functions to delay a curing reaction of the epoxy
resins, the pot life of the pressure-sensitive or bonding adhesive
layer 2 can be improved, and the storage stability of the
pressure-sensitive or bonding adhesive layer 2 can be improved.
[0039] (Liquid Epoxy Resin)
[0040] The liquid epoxy resin functions to impart a practicable
pressure-sensitive adhesive strength and a high adhesive strength
to the pressure-sensitive or bonding adhesive layer 2. Various
epoxy resins may be used without particular limitation as long as
the epoxy resin is liquid at room temperature. For example, one of
or at least two of resins selected from bisphenol A epoxy resins,
bisphenol F epoxy resins, biphenyl epoxy resins, hydrogenated
bisphenol A epoxy resin, aliphatic epoxy resins, stilbene epoxy
resins, o-cresol novolak epoxy resins, phenol novolak epoxy resins,
modified phenol epoxy resins, triphenolmethane epoxy resins, alkyl
modified triphenolmethane epoxy resins, triazine nucleus-containing
epoxy resins, naphthalene epoxy resins, dicyclopentadiene epoxy
resins, dicyclopentadiene modified phenol epoxy resin, and
glycidylamine epoxy resins may be mentioned as the epoxy resin.
[0041] Among them, bisphenol epoxy resins such as bisphenol A epoxy
resin and bisphenol F epoxy resins are preferred, for example, from
the viewpoint of improving mechanical strength, curability, heat
resistance, and adhesion. Bisphenol A epoxy resins are particularly
preferred. In the bisphenol A epoxy resins, those containing one to
three bisphenol skeletons in a main chain thereof are preferred
because they are liquid at room temperature. In the present
application, the room temperature means 23.degree. C..+-.2.degree.
C.
[0042] Preferably, the liquid epoxy resin has a mass average
molecular weight (Mw) of 300 to 2000. The liquid epoxy resin having
a mass average molecular weight (Mw) in the range of 300 to 2000 is
preferred because of good compatibility with the acrylic resin.
Preferably, the liquid epoxy resin has an epoxy equivalent (g/eq.)
of 100 (inclusive) to 800 (exclusive). The liquid epoxy resin
having an epoxy equivalent in the above-defined range is preferred,
because high durability can be imparted to the pressure-sensitive
or bonding adhesive layer 2 after curing, for example, by heating
or ultraviolet light irradiation and high adhesive strength can be
imparted. The epoxy equivalent refers to the number of grams of
resin containing 1 gram equivalent epoxy groups as measured by a
method according to JIS K 7236.
[0043] The content of the liquid epoxy resin is preferably 20% by
mass to 80% by mass, more preferably 25% by mass to 75% by mass,
based on the total amount of the liquid epoxy resin and the solid
epoxy resin. When the content of the liquid epoxy resin is in the
above-defined range, a pressure-sensitive adhesive strength
suitable for practical use and a high adhesive strength can be
imparted to the pressure-sensitive or bonding adhesive layer 2.
When the content of the liquid epoxy resin is less than 20% by
mass, the pressure-sensitive adhesive strength of the
pressure-sensitive or bonding adhesive layer 2 is lowered,
sometimes making it impossible to apply the pressure-sensitive or
bonding adhesive layer 2 to concrete or sometimes making it
impossible to apply a repairing or reinforcing sheet to the
pressure-sensitive or bonding adhesive layer 2. When the content of
the liquid epoxy resin is more than 80% by mass, the aggregation
force of the pressure-sensitive or bonding adhesive layer 2 is
likely to be lowered, sometimes leading to lowered separability of
the pressure-sensitive or bonding adhesive layer 2 or lowered
adhesive strength of the pressure-sensitive or bonding adhesive
layer 2 after curing, for example, by heating or ultraviolet light
irradiation.
[0044] (Solid Epoxy Resin)
[0045] The solid epoxy resin functions to impart a high adhesive
strength to the pressure-sensitive or bonding adhesive layer 2
after curing, for example, by heating or ultraviolet light
irradiation and, at the same time, to impart a high aggregation
force to the pressure-sensitive or bonding adhesive layer 2.
Various epoxy resins may be used without particular limitation as
long as they are solid at room temperature. One of or at least two
of epoxy resins selected from bisphenol A epoxy resins, bisphenol F
epoxy resins, o-cresol novolak epoxy resins, phenol novolak epoxy
resins, modified phenol epoxy resins, naphthalene epoxy resins,
triphenolmethane epoxy resins, alkyl modified triphenolmethane
epoxy resins, triazine nucleus-containing epoxy resins,
dicyclopentadiene epoxy resins, glycidylamine epoxy resins,
biphenyl epoxy resins, biphenylaralkyl epoxy resins, hydrogenated
bisphenol A epoxy resin, aliphatic epoxy resins, stilbene epoxy
resins, and bisphenol A novolak epoxy resins may be mentioned as
the epoxy resin.
[0046] Among them, bisphenol epoxy resins such as bisphenol A epoxy
resin and bisphenol F epoxy resins are preferred, for example, from
the viewpoints of mechanical strength, curability, heat resistance,
and adhesion, and bisphenol A epoxy resins are particularly
preferred. Bisphenol A epoxy resins that usually have 2 to 10
bisphenol skeletons in a main chain thereof are solid at room
temperature.
[0047] Preferably, the solid epoxy resin has a mass average
molecular weight (Mw) of 300 to 5000. Solid epoxy resins having a
mass average molecular weight (Mw) in the above-defined range have
a good compatibility with the acrylic resin. The mass average
molecular weight is more preferably 800 to 3000, and, when the mass
average molecular weight is in this range, for example, a high
adhesive strength and a high durability can be imparted to the
pressure-sensitive or bonding adhesive layer 2. Preferably, the
solid epoxy resin has an epoxy equivalent (g/eq.) of 100 to 2200.
Solid epoxy resins having an epoxy equivalent in the above-defined
range are preferred because they can impart a high durability to
the pressure-sensitive or bonding adhesive layer 2 after curing,
for example, by heating or ultraviolet light irradiation and can
impart a high adhesive strength.
[0048] As with the liquid epoxy resin, the content of the solid
epoxy resin is preferably 20% by mass to 80% by mass, more
preferably 25% by mass to 75% by mass, based on the total amount of
the liquid epoxy resin and solid epoxy resin. When the content is
in the above-defined range, a pressure-sensitive adhesive strength
suitable for practical use and a high adhesive strength can be
imparted to the pressure-sensitive or bonding adhesive layer 2.
When the content of the solid epoxy resin is less than 20% by
weight, the aggregation force of the pressure-sensitive or bonding
adhesive layer 2 is likely to be lowered, sometimes leading to
lowered separability of the pressure-sensitive or bonding adhesive
layer 2 or lowered adhesive strength of the pressure-sensitive or
bonding adhesive layer 2 after curing, for example, by heating or
ultraviolet light irradiation. When the content of the solid epoxy
resin is more than 80% by mass, the pressure-sensitive adhesive
strength of the pressure-sensitive or bonding adhesive layer 2 is
lowered, sometimes making it impossible to apply the
pressure-sensitive or bonding adhesive layer 2 to concrete or
sometimes making it impossible to apply a repairing or reinforcing
sheet to the pressure-sensitive or bonding adhesive layer 2.
[0049] In the present invention, a liquid epoxy resin and a solid
epoxy resin are contained in the pressure-sensitive or bonding
adhesive layer 2. Since these epoxy resins are heat-curable resin
components, after curing of the pressure-sensitive or bonding
adhesive layer 2 having pressure-sensitive adhesive properties, for
example, by heating or ultraviolet light irradiation, the
pressure-sensitive or bonding adhesive layer 2 exhibits a high
adhesive strength. Thus, the pressure-sensitive or bonding adhesive
layer 2 can be strongly bonded to concrete, and, further, a
repairing or reinforcing sheet can be strongly bonded to the
pressure-sensitive or bonding adhesive layer 2. Further, the heat
resistance is enhanced. A high adhesive strength can be imparted to
the pressure-sensitive or bonding adhesive layer 2 having the
composition, for example, by heating or ultraviolet light
irradiation. Thus, even when the concrete surface is a vertical
surface or a ceiling surface, a high level of adhesive properties
can be imparted to the pressure-sensitive or bonding adhesive layer
2, for example, by subjecting the pressure-sensitive or bonding
adhesive layer 2 to heating or ultraviolet light irradiation after
temporal fixation or second temporal fixation after re-application
to the surface. As a result, execution works such as temporal
fixation and main fixation of the pressure-sensitive or bonding
adhesive layer 2 can easily be carried out, and a repairing or
reinforcing sheet can be applied with a high strength.
[0050] (Curing Agent)
[0051] Any curing agent that can cure the liquid epoxy resin and
the solid epoxy resin can be used without particular limitation.
The curing agent may be one that cures the pressure-sensitive or
bonding adhesive layer 2 by applying heat, or one that cures the
pressure-sensitive or bonding adhesive layer 2 by application of
ultraviolet light or electron beams. Further, a curing catalyst
that generates a base through ultraviolet or electron beam
irradiation can be used in combination with the curing agent.
[0052] Curing agents that cures the pressure-sensitive or bonding
adhesive layer 2 by heating include, for example, amine-based
curing agents, phenol-based curing agents, imidazole-based curing
agents, and acid anhydride-based curing agents. Among the curing
agents, the use of latent curing agents is preferred. The latent
curing agent is a curing agent that does not react with an epoxy
group until the temperature reaches a given temperature, but causes
a reaction with the epoxy group when the temperature reaches an
activation temperature by heating. Examples of latent curing agents
include, for example, neutral salts or complexes, blocking
compounds, high-melting compounds, and microcapsule sealed
substances of acidic or basic compounds that can cure epoxy resins
through a reaction with epoxy resins. More specific examples
thereof include dicyandiamides, hydrazide-based curing agents,
amine adduct-based curing agents, and imidazole-based curing
agents. When the latent curing agent is used, the pot life of the
pressure-sensitive or bonding adhesive layer 2 can be improved,
contributing to improved storage stability of an uncured
pressure-sensitive or bonding adhesive layer 2 before heating.
[0053] The content of curing agents that can cure the
pressure-sensitive or bonding adhesive layer 2 by heating may vary
depending upon the type of the curing agent. The content of
catalytic reaction-type curing agents such as imidazole-based
curing agent is preferably 1% by mass to 20% by mass based on the
total amount of the liquid epoxy resin and the solid epoxy resin.
Further, the content of curing agents that react with epoxy resins
in an equivalent reaction, for example, phenol-based curing agents
and acid anhydride-based curing agents is preferably 0.8 to 1.2
equivalents based on the epoxy equivalent of the liquid epoxy resin
and the solid epoxy resin.
[0054] Curing agents that cure the pressure-sensitive or bonding
adhesive layer 2 by ultraviolet light or electron beam irradiation
are those that release substances which initiate cationic
polymerization, for example, by ultraviolet light or electron beam
irradiation and optionally applying heat. Curing agents that
initiate cationic polymerization include, for example, sulfonic
esters, imide sulfonate, dialkyl-4-hydroxysulfonium salts,
arylsulfonic acid-p-nitrobenzyl esters, silanol-aluminum complexes,
aromatic iodonium salts, aromatic sulfonium salts, aromatic
diazonium salts, aromatic phosphonium salts, triazine compounds and
iron arene complexes. These curing agents may be used solely or in
a combination of two or more. Suitable commercially available
products of such curing agents include, for example, SAN-AID SI-60L
(manufactured by Sanshin Chemical Industry Co., Ltd.), SAN-AID
SI-80L (manufactured by Sanshin Chemical Industry Co., Ltd.),
SAN-AID SI-100L (manufactured by Sanshin Chemical Industry Co.,
Ltd.), CI-2064 (manufactured by Nippon Soda Co., Ltd.), Irgacure
261 (manufactured by Chiba Specialty Chemicals K.K.), Adeka Optomer
SP-150 (manufactured by ADEKA), and Adeka Optomer SP-170
(manufactured by ADEKA).
[0055] A combination of a mercapto group-containing curing agent (a
polythiol-based curing agent) or a phenolic hydroxyl
group-containing curing agent with a curing catalyst that generates
a base by ultraviolet or electron beam irradiation may be used as
the curing agent. Photobase generators are preferred as the curing
catalyst. Since the photobase generator is a curing catalyst that
has little or no basic properties before light irradiation, layer
formation is possible.
[0056] Examples of preferred photobase generators include photobase
generators that are represented by the following chemical formula
and generate bases by ultraviolet light or electron beam
irradiation and heating. In the following chemical formula, R.sup.1
and R.sup.2 each independently represent hydrogen or a monovalent
organic group and may be the same or different; R.sup.1 and R.sup.2
may be combined to form a cyclic structure, provided that at least
one of R.sup.1 and R.sup.2 represents a monovalent organic group;
and R.sup.3, R.sup.4, R.sup.5, and R.sup.6 each represent hydrogen,
a halogen, or a monovalent organic group and may be the same or
different, or two or more of R.sup.3, R.sup.4, R.sup.5, and R.sup.6
may be combined to form a cyclic structure.
##STR00001##
[0057] The photobase generator generates a base upon mere
application of electromagnetic waves such as ultraviolet light or
electron beams. The generation of the base is accelerated by proper
heating. Accordingly, a combination of the application of
electromagnetic waves such as ultraviolet light or electron beams
with heating can effectively generate bases at a low
electromagnetic wave irradiation dose. The photobase generator
refers to an agent that does not exhibit activity under ordinary
temperature and pressure conditions but generates a base upon
exposure, for example, to ultraviolet light or electron beams as
external stimulus. The photobase generator has the above specific
structure. Therefore, upon electromagnetic wave irradiation, a
(--CH.dbd.CH--C(.dbd.O)--) moiety in the chemical formula is
isomerized to a cis form, and, further, upon heating, cyclization
occurs to generate an amine NHR1R2 that is a base.
[0058] When the curing agent that cures the pressure-sensitive or
bonding adhesive layer 2 by ultraviolet light or electron beam
irradiation is a curing agent that initiates cationic
polymerization upon light irradiation, the content of the curing
agent is preferably 1% by mass to 10% by mass based on the total
amount of the liquid epoxy resin and the solid epoxy resin. When
the curing agent that reacts with epoxy resins in an equivalent
reaction, for example, phenol-based curing agents and acid
anhydride-based curing agents is used, the content of the curing
agent is preferably 0.8 to 1.2 equivalents based on the epoxy
equivalent of the liquid epoxy resin and the solid epoxy resin.
When the curing agent is used in combination with the curing
catalyst in an equivalent reaction system of epoxy resins, such as
photobase generators, the content is preferably 0.5% by mass to 10%
by mass based on the total amount of the liquid epoxy resin and the
solid epoxy resin.
[0059] The type and content of constituent materials contained in
the pressure-sensitive or bonding adhesive layer 2 can be
specified, for example, by subjecting the pressure-sensitive or
bonding adhesive layer 2 to a gas chromatography mass analysis.
[0060] (Other Components)
[0061] As long as the object of the present invention is sacrified,
the pressure-sensitive or bonding adhesive layer 2 may optionally
contain various additives such as coupling agents for an
improvement in adhesion between concrete and the pressure-sensitive
or bonding adhesive layer 2 and leveling agents for an improvement
in coatability of compositions for pressure-sensitive or bonding
adhesive layer formation. Further, the pressure-sensitive or
bonding adhesive layer 2 may contain, for example, tackifiers for
pressure-sensitive adhesive strength improvement purposes and
fillers for shearing strength improvement purposes.
[0062] One of or at least two of resins selected from, for example,
rosin-based resins, modified rosin-based resins, terpene-based
resins, terpene phenol-based resins, aromatic modified
terpene-based resins, C5 or C9 petroleum-based resins, and
coumarone resins may be mentioned as the tackifier.
[0063] One of or at least two of materials selected from, for
example, inorganic fillers such as silica, clay, glass balloon,
alumina balloon, and ceramic balloon, organic fillers such as nylon
beads, acrylic beads, and silicon beads, single fibers formed of,
for example, glass, polyester, rayon, nylon, cellulose, and acetate
may be mentioned as the filler.
[0064] The thickness of the pressure-sensitive or bonding adhesive
layer 2 is preferably 150 .mu.m to 500 .mu.m, more preferably 150
.mu.m to 300 .mu.m. The pressure-sensitive or bonding adhesive
layer 2 having a thickness in the above-defined range has
pressure-sensitive adhesion to concrete and pressure-sensitive
adhesion to the repairing or reinforcing sheet and exhibits a high
adhesive strength after curing, for example, by heating or
ultraviolet irradiation. When the thickness of the
pressure-sensitive or bonding adhesive layer 2 is less than 150
.mu.m, since the thickness is so small that the pressure-sensitive
adhesive strength and the adhesive strength are sometimes
unsatisfactory. On the other hand, a pressure-sensitive or bonding
adhesive layer 2 thickness of more than 500 .mu.m is
disadvantageous in that curing, for example, after heating or
ultraviolet irradiation of the pressure-sensitive or bonding
adhesive layer 2 does not satisfactorily proceed, or the curing
time is long.
[0065] The pressure-sensitive or bonding adhesive layer 2 may be
formed by coating a composition for pressure-sensitive or bonding
adhesive layer formation on a base and drying the as-coated
composition for pressure-sensitive or bonding adhesive layer
formation. The composition for pressure-sensitive or bonding
adhesive layer formation contains an acrylic resin having a glass
transition temperature of 15.degree. C. or below, further contains
a liquid epoxy resin, a solid epoxy resin, and a curing agent, and
optionally contains the above-described various additives, solvents
and the like. The solvent may be optionally contained in any mixing
amount for viscosity modification purposes. Such solvents include
alcohols such as isopropyl alcohol, methanol, and ethanol; ketones
such as methyl ethyl ketone, methyl isobutyl ketone, and
cyclohexanone; esters such as ethyl acetate and butyl acetate;
halogenated hydrocarbons; aromatic hydrocarbons such as toluene and
xylene; or mixtures thereof.
[0066] Any base that can form the pressure-sensitive or bonding
adhesive layer 2 may be used without particular limitation.
However, a separation film 1 subjected to easy-separation treatment
is preferred. The separation film 1 will be described in detail in
connection with a pressure-sensitive or bonding adhesive sheet 10
that will be described later.
[0067] The composition for pressure-sensitive or bonding adhesive
layer formation is prepared by mixing the above materials and
stirring the mixture for dissolution. The stirrer usable for
stirring is not particularly limited, and examples thereof include
conventional kneading and dispersing machines, for example, twin
roll mills, three-roll mills, pebble mills, trommels, high-speed
impeller dispergators, high-speed stone mills, high-speed impact
mills, dispers, high-speed mixers, ribbon blenders, cokneaders,
intensive mixers, tumblers, blenders, dispersers, homogenizers, and
ultrasonic dispergators.
[0068] The composition for pressure-sensitive or bonding adhesive
layer formation may be coated by any method without particular
limitation. Examples of methods using printing include gravure
printing, flexo printing, and offset printing. Coating methods
include, for example, roll coating, reverse coating, Komma coating,
knife coating, die coating, and gravure coating.
[0069] The drying of the as-coated composition for
pressure-sensitive or bonding adhesive layer formation is
preferably carried out under such conditions that the solvent
contained in the composition for pressure-sensitive or bonding
adhesive layer formation can be satisfactorily volatilized and, at
the same time, a lowering in pressure-sensitive adhesive properties
due to excessive acceleration of curing of the liquid epoxy resin
and the solid epoxy resin does not occur. The drying is genially
carried out by holding at a temperature of 50.degree. C. to
100.degree. C. for 2 to 20 min.
[0070] As described above, the pressure-sensitive or bonding
adhesive layer 2 contains an acrylic resin having a glass
transition temperature of 15.degree. C. or below and a liquid epoxy
resin and thus has a pressure-sensitive adhesive strength.
Consequently, the pressure-sensitive or bonding adhesive layer 2
can be temporarily fixed to concrete, and a repairing or
reinforcing sheet can be temporarily fixed to the
pressure-sensitive or bonding adhesive layer 2. Further, the
pressure-sensitive or bonding adhesive layer 2 and the repairing or
reinforcing sheet after the temporal fixation can be separated and
again temporarily fixed or fixed. Further, since the
pressure-sensitive or bonding adhesive layer 2 contains a liquid
epoxy resin and a solid epoxy resin, a high adhesive strength can
be imparted, for example, after heating or ultraviolet light
irradiation. Consequently, the pressure-sensitive or bonding
adhesive layer 2 can be strongly bonded to concrete, and, further,
a repairing or reinforcing sheet can be strongly bonded to the
pressure-sensitive or bonding adhesive layer 2. Further, the
pressure-sensitive or bonding adhesive layer 2 develops a
pressure-sensitive adhesive strength and an adhesive strength, and,
thus, even when the concrete surface is a vertical surface or a
ceiling surface, the pressure-sensitive or bonding adhesive layer 2
can easily be temporarily fixed or fixed to concrete. Furthermore,
since a pressure-sensitive or bonding adhesive layer 2 in a sheet
form or a pressure-sensitive or bonding adhesive sheet 10 including
a pressure-sensitive or bonding adhesive layer 2 is used, there is
no need to provide a conventional adhesive in a construction site
for repair or reinforcement of concrete, contributing to a
reduction in a workload in construction. The pressure-sensitive or
bonding adhesive layer 2 or the pressure-sensitive or bonding
adhesive sheet 10 including the pressure-sensitive or bonding
adhesive layer 2 can be preferably used for concrete repair or
reinforcement and can repair or reinforce the concrete.
[0071] [Pressure-Sensitive or Bonding Adhesive Sheet]
[0072] As shown, for example, in FIGS. 1B and 1C and 2A, a
pressure-sensitive or bonding adhesive sheet 10 (10A, 10B, and 10C)
includes a pressure-sensitive or bonding adhesive layer 2 as
described above and a separation film 1 provided on one surface (S1
or S2) of the pressure-sensitive or bonding adhesive layer 2. The
pressure-sensitive or bonding adhesive sheet 10 may be a
pressure-sensitive or bonding adhesive sheet 10A, 10C including a
separation film 1 on one surface S2 only, or alternatively may be a
pressure-sensitive or bonding adhesive sheet 10B including
separation films 1, 1' on respective surfaces S1, S2.
[0073] For example, as shown in FIGS. 2A and 2B, a
pressure-sensitive or bonding adhesive sheet 10 (10C,10D) includes
a pressure-sensitive or bonding adhesive layer 2 as described above
and a repairing or reinforcing sheet 3 provided on surface S2 of
the pressure-sensitive or bonding adhesive layer 2. The
pressure-sensitive or bonding adhesive sheet 10 may be a
pressure-sensitive or bonding adhesive sheet 10C including a
repairing or reinforcing sheet 3 provided on one surface S2 of the
pressure-sensitive or bonding adhesive layer 2 and a separation
film 1 provided on the other surface S1 of the pressure-sensitive
or bonding adhesive layer 2, or alternatively may be a
pressure-sensitive or bonding adhesive sheet 10D including a
repairing or reinforcing sheet 3 provided on one surface S2 of the
pressure-sensitive or bonding adhesive layer 2, no element being
provided on the other surface S1.
[0074] As shown in FIGS. 3A, 3B, and 3C, a pressure-sensitive or
bonding adhesive sheet 10 (10E,10F,10G) includes a
pressure-sensitive or bonding adhesive layer 2' provided on the
repairing or reinforcing sheet 3 constituting the
pressure-sensitive or bonding adhesive sheet 10C, 10D shown in
FIGS. 2A and 2B. That is, the pressure-sensitive or bonding
adhesive sheet 10 shown in FIG. 3 includes the pressure-sensitive
or bonding adhesive layer 2, a repairing or reinforcing sheet 3
provided on one surface S2 of the pressure-sensitive or bonding
adhesive layer 2, and a pressure-sensitive or bonding adhesive
layer 2' provided on the repairing or reinforcing sheet 3. As shown
in FIGS. 3A and 3C, a separation film 1' may be provided on the
pressure-sensitive or bonding adhesive layer 2', or alternatively,
as shown in FIG. 3B, no separation film may be provided on the
pressure-sensitive or bonding adhesive layer 2'. The expression "on
a repairing or reinforcing sheet 3" refers to on a surface of the
repairing or reinforcing sheet 3 remote from the pressure-sensitive
or bonding adhesive layer 2. In FIG. 3, reference number ST
designates a surface on the repairing or reinforcing sheet side of
the pressure-sensitive or bonding adhesive layer 2', and reference
character S1' designates a surface of the pressure-sensitive or
bonding adhesive layer 2' remote from the repairing or reinforcing
sheet.
[0075] The pressure-sensitive or bonding adhesive layer 2' may
include the same components as the pressure-sensitive or bonding
adhesive layer 2 or components different from the
pressure-sensitive or bonding adhesive layer 2.
[0076] <Separation Film>
[0077] As shown in FIGS. 1 and 2, the separation film 1 is provided
on one surface (S1 or S2) or both surfaces (S1 and S2) of the
pressure-sensitive or bonding adhesive layer 2. The separation film
1 covers one surface (S1 or S2) or both surfaces (S1 and S2) of the
pressure-sensitive or bonding adhesive layer 2 and functions to
protect the pressure-sensitive or bonding adhesive layer 2 before
use. As shown in FIG. 1B, the separation film 1 may be provided on
a surface S2 that is one of surfaces S1, S2 of the
pressure-sensitive or bonding adhesive layer 2 and located remote
from the surface S1 that is applied to concrete, or alternatively,
as shown in FIG. 10, may be provided on both surfaces, that is, the
surface S2 and the surface S1 that is applied to concrete.
[0078] As shown in FIGS. 2A and 3A, the separation film 1 may be
provided on a surface S1 that is one of surfaces S1, S2 of the
pressure-sensitive or bonding adhesive layer 2 and is a surface to
be applied to concrete. As shown in FIGS. 3A and 3C, when a
pressure-sensitive or bonding adhesive layer 2' is provided on the
repairing or reinforcing sheet 3, a separation film 1' may be on
the pressure-sensitive or bonding adhesive layer 2'.
[0079] In the embodiment shown in FIG. 1B, for example, the
pressure-sensitive or bonding adhesive sheet may be in the form of
a rolled pressure-sensitive or bonding adhesive sheet 10A like a
general pressure-sensitive adhesive tape. In the pressure-sensitive
or bonding adhesive sheet 10A, construction may be carried out by
applying the surface S1, a surface to be applied to concrete, then
separating the separation film 1 provided on the surface S2, a
surface remote from the surface S1, and applying a repairing or
reinforcing sheet to the exposed pressure-sensitive or bonding
adhesive layer 2. On the other hand, in the embodiment shown in
FIG. 1C, for example, the pressure-sensitive or bonding adhesive
sheet may be in the form of a flat pressure-sensitive or bonding
adhesive sheet 10B. In the pressure-sensitive or bonding adhesive
sheet 10B, construction may be carried out by separating the
separation film 1' on the surface S1, a surface to be applied to
concrete, applying the pressure-sensitive or bonding adhesive layer
2 to concrete, then separating the separation film 1 provided on
the surface S2, a surface remote from the surface S1, and applying
a repairing or reinforcing sheet to the exposed pressure-sensitive
or bonding adhesive layer 2. Alternatively, in the
pressure-sensitive or bonding adhesive sheet 10B, construction may
be carried out by separating the separation film 1 on the surface
S2 remote from the surface S1, a surface to be applied to concrete,
applying a repairing or reinforcing sheet to the exposed
pressure-sensitive or bonding adhesive layer 2, then separating in
this state the separation film 1' on the surface S1, a surface to
be applied to concrete, and applying the exposed pressure-sensitive
or bonding adhesive layer 2 to the concrete. In the following
description, the separation film 1 and the separation film 1' are
collectively called "separation film 1."
[0080] Preferably, the surface of the separation film 1 on the
pressure-sensitive or bonding adhesive layer side has been
subjected to easy-separation treatment. The separation film 1
subjected to easy-separation treatment can easily be separated, for
example, from the pressure-sensitive or bonding adhesive layer 2
after the application of the pressure-sensitive or bonding adhesive
layer 2 provided in the pressure-sensitive or bonding adhesive
sheet 10 to concrete.
[0081] The separation film 1 is not particularly limited, and
various films can be used, as long as separation film 1 has a
strength and flexibility on such a level that the separation film 1
when provided separably on the surface of the pressure-sensitive or
bonding adhesive layer 2 can protect the pressure-sensitive or
bonding adhesive layer 2. Materials for the separation film 1
include, for example, publicly known resins such as polyester-based
resins, polypropylene-based resins, polyvinyl chloride-based
resins, fluorine-based resins, polystyrene-based resins,
polyacrylic resins, cellulosic resins, polycarbonate-based resins,
polyamide-based resins, polyolefin-based resins, polyvinyl
alcohol-based resins, polyimide-based resins, phenol-based resins,
and polyurethane-based resins. The separation film 1 may be a
synthetic resin film formed of one of these resins, may be a
synthetic resin film formed of a combination of two or more reins,
or may be a composite film formed of a laminate of synthetic resin
films of a single type of resin or a combination of different types
of resins.
[0082] Among others, the separation film 1 formed of polyester
resins or polycarbonate-based resins is preferred, for example,
from the viewpoints of transparency, heat resistance, dimensional
stability, rigidity, flexibility, suitability for lamination, and
cost. Examples of polyester-based resins include polyethylene
terephthalate, polyethylene naphthalate, polybutylene
terephthalate, polybutylene naphthalate, polyallylate, and
polytetraethylene terephthalate. Polyethylene terephthalate is
particularly preferred from the viewpoints of handleability and
cost.
[0083] Preferably, the easy-separation treatment is carried out on
the surface of the separation film 1 so that the separation film 1
can easily be separated from the pressure-sensitive or bonding
adhesive layer 2. Preferably, for example, a easy-separation layer
(not shown) is provided by the easy-separation treatment. The
easy-separation layer is provided by coating a separating agent.
Various separating agents may be applied without particular
limitation. Examples thereof include water-soluble resins,
hydrophilic resins, waxes, silicone resins, fluoro resins,
aminoalkyd resins, melamine-based resins, polyester resins, and
acrylic resins. Any method may be adopted for coating of the
separating agent without particular limitation and examples thereof
include roll coating, gravure coating, and spray coating.
[0084] Preferably, the surface of the separation film 1 on
easy-separation layer formation side has been subjected to
easy-bonding treatment for easy-separation layer adhesion
enhancement purposes. The easy-bonding treatment is preferably
treatment that improves the wettability of the separating agent.
Examples of such treatment include corona discharge treatment,
plasma treatment, ozone treatment, flame treatment, primer
treatment, preheat treatment, dust removal treatment, vapor
deposition treatment, and alkali treatment.
[0085] Any production method of the separation film 1 may be used
without particular limitation, and examples thereof include
solution casting, melt extrusion, and calendaring. A highly
separable separation film 1 can be produced by optionally
subjecting one surface (S1 or S2) or both surfaces (S1 and S2) of
the produced separation film 1 to the easy-separation treatment and
the easy-bonding treatment. The thickness of the separation film 1
is not particularly limited and may be, for example, 5 .mu.m to 200
.mu.m.
[0086] Commercially available products of the separation film 1 may
be used, and examples thereof include 38 .mu.m-thick polyester
films (manufactured by Mitsui Chemicals Tohcello, Inc., tradename:
SP-PET-01) having one surface subjected to easy-separation
treatment with a silicone-based separating agent.
[0087] <Repairing or Reinforcing Sheet>
[0088] As described in the column of a repairing or reinforcing
method that will be described later, the repairing or reinforcing
sheet 3 is sometimes used as a sheet separate from the
pressure-sensitive or bonding adhesive layer 2 and the
pressure-sensitive or bonding adhesive sheet 10. Here, however, an
embodiment will be described in which the repairing or reinforcing
sheet 3 is integrally provided as a constituent element of the
pressure-sensitive or bonding adhesive sheet 10.
[0089] As shown in FIGS. 2A and 2B and FIGS. 3A, 3B, and 3C, the
repairing or reinforcing sheet 3 may be optionally provided on one
surface S2 of the pressure-sensitive or bonding adhesive layer 2
constituting the pressure-sensitive or bonding adhesive sheet 10.
As shown, for example, in FIG. 2A, the surface S2 is a surface
remote from the surface S1 that is one of surfaces SI, S2 of the
pressure-sensitive or bonding adhesive layer 2 and a surface to be
applied to concrete. As shown in FIG. 2A and FIG. 3A, a separation
film 1 may be provided on the surface S1, a surface to be applied
to concrete, or alternatively, as shown in FIG. 2B and FIGS. 3B and
3C, no separation film may be provided. The repairing or
reinforcing sheet 3 may be provided on the pressure-sensitive or
bonding adhesive layer 2 by a publicly known method such as heat
lamination.
[0090] In an embodiment shown in FIG. 2A and FIG. 3A, for example,
the pressure-sensitive or bonding adhesive sheet may be in the form
of a flat pressure-sensitive or bonding adhesive sheet 10C,10E. In
the flat pressure-sensitive or bonding adhesive sheet 100,10E,
construction may be carried out by separating the separation film 1
on the surface S1, a surface to be applied to concrete and applying
the exposed pressure-sensitive or bonding adhesive layer 2 to
concrete. In the pressure-sensitive or bonding adhesive sheet
10C,10E, the repairing or reinforcing sheet 3 is previously in a
pressure-sensitively adhered state to the pressure-sensitive or
bonding adhesive layer 2. Thus, the sheet can easily be applied. On
the other hand, in an embodiment shown in FIG. 2B and FIGS. 3B and
3C, the pressure-sensitive or bonding adhesive sheet may be in the
form of a rolled pressure-sensitive or bonding adhesive sheet
10D,10G. In the pressure-sensitive or bonding adhesive sheet 10D,
10G, construction may be carried out by applying the surface S1, a
surface to be applied to concrete, to concrete. Also in the
pressure-sensitive or bonding adhesive sheet 10D, 10G, since the
repairing or reinforcing sheet 3 is also previously in a
pressure-sensitively adhered state to the pressure-sensitive or
bonding adhesive layer 2, the sheet can easily be applied.
[0091] A pressure-sensitive or bonding adhesive sheet 10 (10E, 10F,
10G) includes a repairing or reinforcing sheet 3 provided on one
surface S2 of the pressure-sensitive or bonding adhesive layer 2
and a pressure-sensitive or bonding adhesive layer 2' provided on
the repairing or reinforcing sheet 3. Accordingly, when the
repairing or reinforcing sheet 3 has, for example, a fiber material
layer that will be described later, the pressure-sensitive or
bonding adhesive layer 2' can function to absorb irregularities in
the fiber material layer to reduce the size of the irregularities.
As a result, the smoothness of the pressure-sensitive or bonding
adhesive sheet 10 (10E, 10F, 10G) can be enhanced, and, thus,
design of the repaired or reinforced concrete can be enhanced.
[0092] The pressure-sensitive or bonding adhesive layer 2' can
function as a protective layer that prevents a deterioration in the
repairing or reinforcing sheet 3. Consequently, the
pressure-sensitive or bonding adhesive sheet 10 (10E, 10F, 10G) can
enhance storage stability before application to concrete and can
enhance durability after application to the concrete.
[0093] Further, since pressure-sensitive or bonding adhesive layers
(2, 2') are provided on respective surfaces of the repairing or
reinforcing sheet 3, the pressure-sensitive or bonding adhesive
sheet 10 (10E, 10F, 10G) can function like a pressure-sensitive or
bonding adhesive double coated tape. Concrete can be applied to a
surface S1 of the pressure-sensitive or bonding adhesive layer 2 in
the pressure-sensitive or bonding adhesive sheet 10, and a
functional sheet or layer that will be described later can be
applied to a surface S1' of the pressure-sensitive or bonding
adhesive layer 2'. In the pressure-sensitive or bonding adhesive
sheet 10E, 10G, a functional sheet or layer may be provided instead
of the separation film 1'.
[0094] A sheet or layer having one of or at least two of functions,
for example, light resistance, water resistance, antifouling
properties, weathering resistance, impact resistance, scratch
resistance, acid resistance, alkali resistance, and design may be
mentioned as the functional sheet or layer.
[0095] Any sheet that can repair or reinforce concrete can be used
as the repairing or reinforcing sheet 3 without particular
limitation. Examples thereof include sheets that can prevent the
penetration of concrete degradation factors, sheets that can
reinforce concrete having lowered strength, sheets that have other
functions and can repair or reinforce concrete, or sheets that
satisfy all the above properties.
[0096] For example, a repairing or reinforcing sheet including a
base formed of a synthetic resin film, a resin material layer
provided on one surface of the base, and a fiber material layer
provided on the other surface of the base may be mentioned as the
repairing or reinforcing sheet 3. The resin material layer can
function as a protective layer, and the fiber material layer can
function as a reinforcing layer.
[0097] Examples of materials for the synthetic resin film as the
base include polyester resins, polypropylene-based resins,
polyvinyl chloride-based resins, fluorine-based resins,
polystyrene-based resins, polyacrylic resins, cellulosic resins,
polycarbonate-based resins, polyamide-based resins,
polyolefin-based resins, polyvinyl alcohol-based resins,
polyimide-based resins, phenol-based resins, and polyurethane-based
resins.
[0098] The resin material layer functions to prevent damage to
concrete and a bonded portion between the concrete and the
pressure-sensitive or bonding adhesive layer 2 caused by external
degradation factors. Representative degradation factors include
water, oxygen, carbon dioxide, or chloride ions. For example, one
of or at least two of resins selected from fluorine-based resins,
acrylic resins, acryl silicone-based resins, acryl fluorine-based
resins, silicone-based resins, urethane-based resins, and
chlorine-based resins may be mentioned as the resin for
constituting the resin material layer. These resin materials have
weathering resistance, antifouling properties, water resistance,
salt shielding properties or other functions according to the types
thereof and thus are preferably selected according to the
properties.
[0099] Examples of the fiber material layer include those formed of
one of or at least two of materials selected from woven fabrics,
knitted fabrics, non-woven fabrics, layered fabrics, synthetic
resin foams, and papers. One of or at least two of materials
selected from polyester fibers, polyamide fibers, aramid fibers,
vinylon fibers, carbon fibers, glass fibers, and polyolefin fibers
may be mentioned as the material for constituting the fiber
material layer. Among them, polyester fibers, polyamide fibers,
aramid fibers, vinylon fibers, and polyolefin fibers are preferred
because of lightness and high strength. These fibers may be blended
fabrics, may be those in which warps and wefts are used, or may be
laminated to form a multilayered structure. The fiber material
layer may be bonded to the synthetic resin film as the base through
a resin material. The resin material is not particularly limited,
and the same resin materials as used in the resin material layer
may be used,
[0100] Preferably, the repairing or reinforcing sheet 3 has a
strength (a reinforcement strength) high enough to support
separated concrete pieces or concrete pieces that are likely to be
separated, for example, when a part of a concrete structure has
been separated or is likely to be separated. The strength is
preferably not less than 1500 N at a displacement of not less than
10 mm, for example, in a punching test specified in former Japan
Highway Public Corporation (East Nippon Expressway Company Limited,
Central Nippon Expressway. Co., Ltd., and West Nippon Expressway
Co., Ltd.).
[0101] The repairing or reinforcing sheet 3 can be produced, for
example, by a production process including the steps of: providing
a resin material layer on one surface of a base; and providing a
fiber material layer on the other surface of the base. The resin
material layer can be formed on one surface of the base, for
example, by coating a resin material on a base and then curing the
coating. The fiber material layer can be formed on the other
surface of the base, for example, by coating a composite material
containing a fiber material and a resin material on a base and
curing the resin material.
[0102] Here the repairing or reinforcing sheet 3 has been
described. However, it should be noted that materials for
constituting the sheet vary dependent upon whether the sheet is a
repairing sheet or a reinforcing sheet that is selected according
to applications. The thickness of the repairing or reinforcing
sheet varies dependent upon whether the sheet is used for repair
purposes or for reinforcement purposes, but is generally in the
range of 0.01 mm to 1.0 mm.
[0103] As described above, the pressure-sensitive or bonding
adhesive sheet 10 can be used for the repair or reinforcement of
concrete by pressure-sensitive adhesion or bonding adhesion to
concrete. The pressure-sensitive or bonding adhesive layer 2
constituting the pressure-sensitive or bonding adhesive sheet 10
includes an acrylic resin having a glass transition temperature of
15.degree. C. or below and a liquid epoxy resin and thus has a
pressure-sensitive adhesive strength. Consequently, a method may be
adopted that includes temporarily fixing one surface of a
pressure-sensitive or bonding adhesive layer 2 to concrete,
separating the separation film 1, and then temporarily fixing a
repairing or reinforcing sheet to the other surface. After the
temporal fixation of the pressure-sensitive or bonding adhesive
layer 2 and the repairing or reinforcing sheet, the
pressure-sensitive or bonding adhesive layer 2 and the repairing or
reinforcing sheet may be separated and again temporarily fixed or
fixed. Further, in the pressure-sensitive or bonding adhesive sheet
10 including the pressure-sensitive or bonding adhesive layer 2,
there is no need to provide a conventional adhesive in a
construction site for repair or reinforcement of concrete,
contributing to a reduction in a workload in construction. Further,
the pressure-sensitive or bonding adhesive sheet 10 including the
pressure-sensitive or bonding adhesive layer 2 can be preferably
used for concrete repair or reinforcement and can repair or
reinforce the concrete.
[0104] [Repairing or Reinforcement Method]
[0105] The concrete repairing or reinforcement method can be
carried out using the pressure-sensitive or bonding adhesive layer
2 and the pressure-sensitive or bonding adhesive sheet 10.
[0106] In a pressure-sensitive or bonding adhesive sheet 10A shown
in FIG. 1B, construction may be carried out by applying the surface
S1, a surface to be applied to concrete, to concrete, then
separating the separation film 1 provided on the other surface S2,
and applying a repairing or reinforcing sheet to the exposed
pressure-sensitive or bonding adhesive layer 2. On the other hand,
in a pressure-sensitive or bonding adhesive sheet 10B shown in FIG.
1C, construction may be carried out by separating the separation
film 1' on the surface S1, a surface to be applied to concrete,
applying the exposed pressure-sensitive or bonding adhesive layer 2
to concrete, then separating the separation film 1 provided on the
other surface S2, and applying a repairing or reinforcing sheet to
the exposed pressure-sensitive or bonding adhesive layer 2.
Further, in the pressure-sensitive or bonding adhesive sheet 10B,
construction may be carried out by separating the separation film 1
on the surface S2 remote from the surface S1, a surface to be
applied to concrete, applying a repairing or reinforcing sheet to
the exposed pressure-sensitive or bonding adhesive layer 2, and, in
this state, separating the separation film 1' on the surface S1,
the surface to be applied to concrete, and applying the exposed
pressure-sensitive or bonding adhesive layer 2 to the concrete.
[0107] In a pressure-sensitive or bonding adhesive sheet 10C shown
in FIG. 2A, construction may be carried out by separating the
separation film 1 on the surface S1, a surface to be applied to
concrete, and applying the exposed pressure-sensitive or bonding
adhesive layer 2 to the concrete. Since the repairing or
reinforcing sheet 3 is previously in a pressure-sensitively adhered
state to the pressure-sensitive or bonding adhesive layer 2, the
construction can easily be carried out. On the other hand, in a
pressure-sensitive or bonding adhesive sheet 10D shown in FIG. 2B,
construction may be carried out by applying the surface S1, a
surface to be applied to concrete, to concrete. Also in the
pressure-sensitive or bonding adhesive sheet 10D, the repairing or
reinforcing sheet 3 is previously in a pressure-sensitively adhered
state to the pressure-sensitive or bonding adhesive layer 2, and,
thus, the construction can easily be carried out.
[0108] In a pressure-sensitive or bonding adhesive sheet 10E shown
in FIG. 3A, as with the pressure-sensitive or bonding adhesive
sheet 10C, construction may be carried out by separating the
separation film 1 provided on the surface S1, a surface to be
applied to concrete, and applying the exposed pressure-sensitive or
bonding adhesive layer 2 to concrete. In the pressure-sensitive or
bonding adhesive sheet 10E, thereafter, if necessary, the
separation film 1' may be separated followed by the provision of a
functional sheet or layer on the exposed pressure-sensitive or
bonding adhesive layer 2'. On the other hand, in a
pressure-sensitive or bonding adhesive sheet 10F, 10G shown in
FIGS. 3B and 3C, as with the pressure-sensitive or bonding adhesive
sheet 10D, construction may be carried out by applying the surface
S1, a surface to be applied to concrete, to concrete. As with the
pressure-sensitive or bonding adhesive sheet 10E shown in FIG. 3A,
the pressure-sensitive or bonding adhesive layer 2' is provided,
and, thus, a functional film or layer can be provided on the
pressure-sensitive or bonding adhesive layer 2'.
[0109] Thus, the repairing or reinforcing sheet is applied to
concrete by pressure-sensitive adhesion or bonding adhesion using
the pressure-sensitive or bonding adhesive sheets 10A to 10G. In
this case, preferably, the pressure-sensitive or bonding adhesive
layer 2 is contact-bonded to concrete, for example, by a roller
from the top of the repairing or reinforcing sheet. Regarding
curing of the pressure-sensitive or bonding adhesive layer 2, heat
curing and contact bonding can be simultaneously carried out with a
heating roller in roller contact bonding, or alternatively, a
method may also be adopted in which roller contact bonding is
followed by heat curing. The temperature at which the heat curing
is carried out may vary depending, for example, upon the type of
the curing agent used, but is generally 100.degree. C. to
150.degree. C. Also when curing is carried out by ultraviolet light
or electron beam irradiation, for example, a method may be adopted
in which ultraviolet light or electron beams are applied for curing
simultaneously with or after contact bonding. Conditions for
ultraviolet light irradiation may vary depending upon the type of
the curing agent, but may be, for example, such that, as described
in working examples that will be described later, the integrated
quantity of light is about 1000 mJ/cm.sup.2 in a wavelength range
of 300 nm to 370 nm. Conditions for electron beam irradiation may
also vary depending upon the type of the curing agent, but may be
such that the irradiation dose is about 50 kGy to 100 kGy.
[0110] According to these curing methods, the liquid epoxy resin
and the solid epoxy resin contained in the pressure-sensitive or
bonding adhesive layer 2 are cured, and, consequently, the
pressure-sensitive or bonding adhesive layer 2 is strongly bonded
to concrete while the repairing or reinforcing sheet can be
strongly bonded to the pressure-sensitive or bonding adhesive layer
2. As a result, the repairing or reinforcing sheet can be strongly
bonded to the concrete. After curing of the pressure-sensitive or
bonding adhesive layer 2, for example, by heating or ultraviolet
irradiation, the cured pressure-sensitive or bonding adhesive layer
2 is held for approximately one day to 14 days. This holding allows
the liquid epoxy resin and the solid epoxy resin to be more fully
cured, and, consequently, the pressure-sensitive or bonding
adhesive layer 2 can develop a higher level of adhesive strength.
As a result, the concrete can be repaired or reinforced with a
higher strength.
EXAMPLES
[0111] The present invention is further illustrated by the
following Examples. The present invention, however, is not limited
to the following Examples unless the Examples go beyond the subject
matter of the present invention.
Example 1
[0112] A 38 .mu.m-thick polyester film (manufactured by Mitsui
Chemicals Tohcello, Inc., tradename: SP-PET-03) having one surface
subjected to easy-separation treatment with a silicone-based
separating agent was provided as a separation film 1. A composition
A having the following composition for pressure-sensitive or
bonding adhesive layer formation was coated by an applicator on the
whole area of the surface of the separation film subjected to
easy-separation treatment. The coated film was dried in a drying
oven at 100.degree. C. for 2 min to form a pressure-sensitive or
bonding adhesive layer 2 having a thickness of 150 .mu.m.
Subsequently, a 38 .mu.m-thick polyester film (manufactured by
Mitsui Chemicals Tohcello, Inc., tradename: SPPET-01) having one
surface subjected to easy-separation treatment with a
silicone-based separating agent was laminated as another separation
film on the other surface of the pressure-sensitive or bonding
adhesive layer 2 to obtain a pressure-sensitive or bonding adhesive
sheet 10B (see FIG. 1(C)) of Example 1 that has one
pressure-sensitive or bonding adhesive layer. The composition A for
pressure-sensitive or bonding adhesive layer formation was prepared
by mixing a liquid epoxy resin and two curing agents together,
stirring the mixture at a rotation speed of 1000 rpm with a disper
for 30 min, then mixing a solid epoxy resin, an acrylic resin, and
a diluting solvent thereinto, and stirring the mixture with a
disper at a rotation speed of 1200 rpm for 30 min.
[0113] (Composition a for Pressure-Sensitive or Bonding Adhesive
Layer Formation)
TABLE-US-00001 Acrylic resin (modified methyl 30 parts by mass
methacrylate-butyl acrylate-methyl methacrylate triblock copolymer
with hydroxyl group introduced thereinto, Tg: -42.degree. C.,
manufactured by Arkema Inc., tradename: M22N) Liquid epoxy resin
(bisphenol A epoxy 80 parts by mass resin, Epoxy equivalent: 190
g/eq., manufactured by Mitsubishi Chemical Corporation, tradename:
jER828) Solid epoxy resin (bisphenol A epoxy resin, 120 parts by
mass Epoxy equivalent: 480 g/eq., manufactured by Mitsubishi
Chemical Corporation, tradename: jER1001) Curing agent (amine-based
curing agent, 7 parts by mass manufactured by Ajinomoto
Fine-Techno. Co. Inc., tradename: Amicure MY-H) Curing agent
(dicyandimide, manufactured 11 parts by mass by Mitsubishi Chemical
Corporation, tradename: DICY) Diluting solvent (Ethyl acetate, 122
parts by mass manufactured by DIC Graphics Corporation)
Example 2
[0114] A pressure-sensitive or bonding adhesive sheet of Example 2
was obtained in the same manner as in Example 1, except that, in
the composition A for pressure-sensitive or bonding adhesive layer
formation in Example 1, the acrylic resin was changed to other
acrylic resin (methyl methacrylate-butyl acrylate-methyl
methacrylate triblock copolymer, Tg: -42.degree. C., manufactured
by Arkema Inc., tradename: M22).
Example 3
[0115] A pressure-sensitive or bonding adhesive sheet of Example 3
was obtained in the same manner as in Example 1, except that, in
composition A for pressure-sensitive or bonding adhesive layer
formation in Example 1, the acrylic resin was changed to other
acrylic resin (ethyl acrylate-butyl acrylate-acrylonitrile
copolymer, Tg: 12.degree. C., manufactured by Nagase ChemteX
Corporation, tradename: SG-P3).
Examples 4 to 9
[0116] Pressure-sensitive or bonding adhesive sheets of Examples 4
to 9 were obtained in the same manner as in Example 1, except that,
in composition A for pressure-sensitive or bonding adhesive layer
in Example 1, the mixing amounts of the acrylic resin, the liquid
epoxy resin, and the solid epoxy resin were changed as specified in
Table 1.
Example 10
[0117] A pressure-sensitive or bonding adhesive sheet of Example 10
was obtained in the same manner as in Example 1, except that the
thickness of the pressure-sensitive or bonding adhesive layer 2 was
changed to 300 .mu.m.
Comparative Example 1
[0118] A pressure-sensitive or bonding adhesive sheet of
Comparative Example 1 was obtained in the same manner as in Example
1, except that, Example 1, the acrylic resin was changed to other
acrylic resin (ethyl acrylate-methyl methacrylate copolymer, Tg:
18.degree. C., manufactured by Negami Chemical Industrial Co.,
Ltd., tradename: W-197C).
Comparative Example 2
[0119] A pressure-sensitive or bonding adhesive sheet of
Comparative Example 2 was obtained in the same manner as in Example
1, except that, in Example 1, the acrylic resin was changed to
other acrylic resin (polymethyl methacrylate, Tg: 105.degree. C.,
manufactured by Toeikasei Co, Ltd., tradename: LC#6500).
Comparative Example 3 to 7
[0120] Pressure-sensitive or bonding adhesive sheets of Comparative
Examples 3 to 7 were obtained in the same manner as in Example 1,
except that, in Example 1, the mixing amounts of the acrylic resin,
the liquid epoxy resin, and the solid epoxy resin were changed as
specified in Table 1.
Example 11
[0121] A pressure-sensitive or bonding adhesive sheet of Example 11
was obtained in the same manner as in Example 1, except that, in
Example 1, composition B for pressure-sensitive or bonding adhesive
layer formation was used instead of composition A for
pressure-sensitive or bonding adhesive layer formation. Composition
B for pressure-sensitive or bonding adhesive layer formation was
prepared by mixing the liquid epoxy resin, the solid epoxy resin,
the acrylic resin, and the diluting solvent together, stirring the
mixture with a disper at a rotation speed of 1200 rpm for 30 min
for dissolution, then further adding a mercapto group-containing
curing agent and photobase generator A, stirring the mixture with a
disper at a rotation speed of 1200 rpm for 30 min for dissolution,
and defoaming the solution.
[0122] (Composition B for Pressure-Sensitive or Bonding Adhesive
Layer Formation)
TABLE-US-00002 Acrylic resin (modified methyl 30 parts by mass
methacrylate-butyl acrylate-methyl methacrylate triblock copolymer
with hydroxyl group introduced thereinto, Tg: -42.degree. C.,
manufactured by Arkema Inc., tradename: M22N) Liquid epoxy resin
(bisphenol A epoxy resin, 80 parts by mass epoxy equivalent: 190
g/eq., manufactured by Mitsubishi Chemical Corporation, tradename:
jER828) Solid epoxy resin (bisphenol A epoxy resin, 120 parts by
mass epoxy equivalent: 480 g/eq., manufactured by Mitsubishi
Chemical Corporation, tradename: jER1001) PEMP as curing agent
having mercapto 90 parts by mass group (pentaerythritol
tetrakis-3-mercaptopropionate, Viscosity: 400-550 mPa s/25.degree.
C., Mercaptan equivalent: 125-137 g/eq, Mitsubishi Chemical
Corporation, tradename: QX40) Photobase generator A (see a
synthesis 10 parts by mass method that will be described later)
Diluting solvent (ethyl acetate, manufactured 122 parts by mass by
DIC Graphics Corporation)
[0123] (Synthesis of Photobase Generator A)
[0124] Methanol (15 mL) was placed in a 100-mL flask, and 2.00 g of
potassium carbonate was added thereto. Subsequently, 10 mL of
methanol was placed in a 50-mL flask.
Ethoxycarbonylmethyl(triphenyl)phosphonium bromide (manufactured by
Tokyo Chemical Industry Co., Ltd.) (2.67 g (6.2 mmol)) and 1.7 g
(6.2 mmol) of 2-hydroxy-4-(5-ethylhexyloxy)-5-ethylbenzaldehyde
were added to and dissolved in the mixture. The thoroughly stirred
methanol solution of potassium carbonate was then slowly added
dropwise to the solution, the mixture was stirred for 3 hr, and the
completion of the reaction was confirmed by TLC. Subsequently,
potassium carbonate was removed by filtration, followed by
concentration under the reduced pressure. After the concentration,
50 mL of a 1 N aqueous sodium hydroxide solution was added, and the
mixture was stirred for one hr. After the completion of the
reaction, triphenylphosphine oxide was removed by filtration,
concentrated hydrochloric acid was added dropwise thereto, and the
reaction solution was acidified. The precipitates were collected by
filtration and were washed with a small amount of chloroform to
give 1.7 g of 2-hydroxy-4-(5-ethylhexyloxy)-5-ethylcinnamic acid.
Subsequently, 1.0 g (3.19 mmol) of
2-hydroxy-4-(5-ethylhexyloxy)-5-ethylcinnamic acid was dissolved
under a nitrogen atmosphere in 10 mL of dehydrated tetrahydrofuran
in a 100-mL three-necked flask.
1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride
(manufactured by Tokyo Chemical Industry Co., Ltd.) (0.73 g (3.83
mmol, 1.2 eq) was added to the solution under an ice bath, and 30
min after the addition, 129 mg (1.52 mmol, 0.95 eq) of piperidine
(manufactured by Tokyo Chemical Industry Co., Ltd.) was added as an
amine thereto, followed by stirring overnight. After the completion
of the reaction, the reaction solution was concentrated, and the
concentrate was dissolved in water. The solution was extracted with
chloroform. The extract was washed with an aqueous hydrogen
carbonate solution, 1 N hydrochloric acid, and saturated brine, was
dried over sodium sulfate, and was then concentrated to give 1.0 g
of photobase generator A represented by formula (I):
##STR00002##
Example 12
[0125] A pressure-sensitive or bonding adhesive sheet of Example 12
was obtained in the same manner as in Example 11, except that, in
composition B for pressure-sensitive or bonding adhesive layer
formation of Example 11, 10 parts by mass of the following
photobase generator B was used instead of photobase generator
A.
[0126] (Synthesis of Photobase Generator B)
[0127] Photobase generator B (0.8 g) of formula (II) was obtained
by the same method as described in the synthesis of photobase
generator A, except that 1.5 g (6.2 mmol) of
2-hydroxy-5-(5-ethylhexyloxyl)benzaldehyde was added instead of
2-hydroxy-4-(5-ethylhexyloxy)-5-ethylbenzaldehyde as photobase
generator A.
##STR00003##
Example 13
[0128] A pressure-sensitive or bonding adhesive sheet was obtained
in the same manner as in Example 1, except that the thickness of
the pressure-sensitive or bonding adhesive layer 2 was changed to
200 .mu.m. One separation film (SP-PET-01) in two separation films
provided on the pressure-sensitive or bonding adhesive layer 2 in
the pressure-sensitive or bonding adhesive sheet was separated. An
aramid fiber (mass per unit area: 90 g/m.sup.2, thickness: about
0.024 mm, manufactured by Fibex Co., Ltd., tradename: AKM-5/5) was
laminated as a reinforcing sheet while heating the exposed
pressure-sensitive or bonding adhesive layer 2 to 60.degree. C.
[0129] Subsequently, another pressure-sensitive or bonding adhesive
sheet was laminated onto the laminated aramid fiber. This
pressure-sensitive or bonding adhesive sheet is also a
pressure-sensitive or bonding adhesive sheet obtained in the same
manner as in Example 1. Also in the pressure-sensitive or bonding
adhesive sheet, as described above, one separation film (SP-PET-01)
in the two separation films was separated, and the exposed
pressure-sensitive or bonding adhesive layer 2 was laminated onto
the araimid fiber while heating the pressure-sensitive or bonding
adhesive layer 2 to 60.degree. C. Thus, a pressure-sensitive or
bonding adhesive sheet 10E (see FIG. 3(A)) having two
pressure-sensitive or bonding adhesive layers was obtained. As
described in the column of [Pressure-sensitive or bonding adhesive
sheet], the pressure-sensitive or bonding adhesive layer provided
on the repairing or reinforcing sheet (aramid fiber) in the
pressure-sensitive or bonding adhesive layers in the
pressure-sensitive or bonding adhesive sheet having two
pressure-sensitive or bonding adhesive layers as shown in FIGS. 3
(A), (B), and (C) is also called a "pressure-sensitive or bonding
adhesive layer 2'." The pressure-sensitive or bonding adhesive
sheet 10E thus obtained has a construction of separation film
(SP-PET-03)/pressure-sensitive or bonding adhesive layer 2/aramid
fiber/pressure-sensitive or bonding adhesive layer 2'/separation
film (SP-PET-03) provided in that order.
Examples 14 and 15
[0130] Pressure-sensitive or bonding adhesive sheets of Examples 14
and 15 were obtained in the same manner as in Example 13, except
that, in Example 13, the mixing amounts of the acrylic resin, the
liquid epoxy resin, and the solid epoxy resin in composition A for
pressure-sensitive or bonding adhesive layer 2 formation and
pressure-sensitive or bonding adhesive layer 2' formation were
changed as specified in Table 2.
Example 16
[0131] A pressure-sensitive or bonding adhesive sheet of Example 16
was obtained in the same manner as in Example 13, except that, in
Example 13, an aramid fiber (mass per unit area: 180 g/m.sup.2,
thickness: about 0.048 mm, manufactured by Fibex Co., Ltd.,
tradename: AKM-10/10) was used instead of the aramid fiber (mass
per unit area: 90 g/m.sup.2, thickness: about 0.024 mm,
manufactured by Fibex Co., Ltd., tradename: AKM-5/5).
Comparative Examples 8 and 9
[0132] Pressure-sensitive or bonding adhesive sheets of Comparative
Examples 8 and 9 were obtained in the same manner as in Example 13,
except that, in Example 13, the mixing amounts of the acrylic
resin, the liquid epoxy resin, and the solid epoxy resin in
composition A for pressure-sensitive or bonding adhesive layer
formation used in the formation of the pressure-sensitive or
bonding adhesive layer 2 and the pressure-sensitive or binding
adhesive layer 2' were changed as specified in Table 2.
Example 17
[0133] A pressure-sensitive or bonding adhesive sheet of Example 17
was obtained in the same manner as in Example 13, except that, in
Example 13, composition B for pressure-sensitive or bonding
adhesive layer formation of Example 11 was used instead of
composition A for pressure-sensitive or bonding adhesive layer
formation.
Example 18
[0134] A pressure-sensitive or bonding adhesive sheet of Example 18
was obtained in the same manner as in Example 13, except that, in
Example 13, composition B for pressure-sensitive or bonding
adhesive layer formation of Example 11 was used instead of
composition A for pressure-sensitive or bonding adhesive layer
formation and, further, an aramid fiber (mass per unit area: 180
g/m.sup.2, thickness: about 0.048 mm, manufactured by Fibex Co.,
Ltd., tradename: AKM-10/10) was used instead of the aramid fiber
(mass per unit area: 90 g/m.sup.2, thickness: about 0.024 mm,
manufactured by Fibex Co., Ltd., tradename: AKM-5/5).
[0135] [Evaluation and Results]
[0136] Compositions of the pressure-sensitive or bonding adhesive
layers 2 constituting the pressure-sensitive or bonding adhesive
sheets 10 of Examples 1 to 12 and Comparative Examples 1 to 7 that
are pressure-sensitive or bonding adhesive sheets having one
pressure-sensitive or bonding adhesive layer as shown in FIG. 1 or
2 are shown in Table 1. Compositions of the pressure-sensitive or
bonding adhesive layer 2 and the pressure-sensitive or bonding
adhesive layer 2' constituting the pressure-sensitive or bonding
adhesive sheets 10 of Examples 13 to 18 and Comparative Examples 8
and 9 that are pressure-sensitive or bonding adhesive sheets having
two pressure-sensitive or bonding adhesive layers as shown in FIG.
3 are shown in Table 2. For example, in Example 1, the content of
the acrylic resin was determined by [30 parts by mass/(30 parts by
mass+80 parts by mass+120 parts by mass).times.100]=13.0% by mass.
For example, in Example 1, the content of the liquid epoxy resin
was determined by [80 parts by mass/(80 parts by mass+120 parts by
mass).times.100]=40.0% by mass, and, for Example 1, the content of
the solid epoxy resin was determined by [120 parts by mass/(80
parts by mass+120 parts by mass).times.100]=60.0% by mass.
TABLE-US-00003 TABLE 1 Pressure-sensitive adhesive layer Acrylic
resin Liquid epoxy resin Solid epoxy resin Mixing Mixing Mixing
Type Tg amount Content amount Content amount Content (tradename)
(.degree. C.) (parts) (mass %) (parts) (mass %) (parts) (mass %)
Example 1 M22N -42 30 13.0 80 40.0 120 60.0 Example 2 M22 -42 30
13.0 80 40.0 120 60.0 Example 3 SG-P3 12 30 13.0 80 40.0 120 60.0
Example 4 M22N -42 100 33.3 50 25.0 150 75.0 Example 5 M22N -42 100
33.3 150 75.0 50 25.0 Example 6 M22N -42 100 33.3 80 40.0 120 60.0
Example 7 M22N -42 10 4.76 80 40.0 120 60.0 Example 8 M22N -42 50
20.0 80 40.0 120 60.0 Example 9 M22N -42 200 50.0 80 40,0 120 60.0
Example 10 M22N -42 30 13.0 80 40.0 120 60.0 Comparative W-197C 18
30 13.0 80 40.0 120 60.0 Example 1 Comparative LC#6500 105 30 13.0
80 40.0 120 60.0 Example 2 Comparative M22N -42 100 100 0 0 0 0
Example 3 Comparative -- -- 0 0 200 100 0 0 Example 4 Comparative
-- -- 0 0 0 0 200 100 Example 5 Comparative M22N -42 100 33.3 200
100 0 0 Example 6 Comparative M22N -42 100 33.3 0 0 200 100 Example
7 Example 11 M22N -42 30 13.0 80 40.0 120 60.0 Example 12 M22N -42
30 13.0 80 40.0 120 60.0 *) Parts are by mass.
TABLE-US-00004 TABLE 2 Pressure-sensitive adhesive layer Acrylic
resin Liquid epoxy resin Solid epoxy resin Mixing Mixing Mixing
Type Tg amount Content amount Content amount Content (tradename)
(.degree. C.) (parts) (mass %) (parts) (mass %) (parts) (mass %)
Example 13 Pressure- M22N -42 30 13 80 40 120 60 sensitive adhesive
layer 2 Pressure- M22N -42 30 13 80 40 120 60 sensitive adhesive
layer 2' Example 14 Pressure- M22N -42 30 13 80 40 120 60 sensitive
adhesive layer 2 Pressure- SG-P3 12 30 13 80 40 120 60 sensitive
adhesive layer 2' Example 15 Pressure- SG-P3 12 30 13 80 40 120 60
sensitive adhesive layer 2 Pressure- SG-P3 12 30 13 80 40 120 60
sensitive adhesive layer 2' Example 16 Pressure- M22N -42 30 13 80
40 120 60 sensitive adhesive layer 2 Pressure- M22N -42 30 13 80 40
120 60 sensitive adhesive layer 2' Comparative Pressure- W-197C 18
30 13 80 40 120 60 Example 8 sensitive adhesive layer 2 Pressure-
W-197C 18 30 13 80 40 120 60 sensitive adhesive layer 2'
Comparative Pressure- -- -- 0 0 200 100 0 0 Example 9 sensitive
adhesive layer 2 Pressure- -- -- 0 0 0 0 200 100 sensitive adhesive
layer 2' Example 17 Pressure- M22N -42 30 13 80 40 120 60 sensitive
adhesive layer 2 Pressure- M22N -42 30 13 80 40 120 60 sensitive
adhesive layer 2' Example 18 Pressure- M22N -42 30 13 80 40 120 60
sensitive adhesive layer 2 Pressure- M22N -42 30 13 80 40 120 60
sensitive adhesive layer 2' *) Parts are by mass.
[0137] The adhesive strength was measured for the
pressure-sensitive or bonding adhesive sheets 10 of Examples 1 to
18 and Comparative Example 6. The pressure-sensitive or bonding
adhesive sheets of Examples 1 to 18 and Comparative Examples 1 to 9
were subjected to the measurement of shearing strength, a punching
test, and the measurement of bond strength.
[0138] (Measurement of Adhesive Strength)
[0139] In the measurement of the adhesive strength of the
pressure-sensitive or bonding adhesive sheets obtained in Examples
1 to 12 and Comparative Example 6, at the outset, the separation
film (SP-PET-01) in the pressure-sensitive or bonding adhesive
sheets was separated, and the exposed pressure-sensitive or bonding
adhesive layer 2 was applied onto a corona-treated surface of a
base (a PET film having one surface subjected to corona treatment,
thickness: 38 .mu.m, manufactured by Toyobo Co., Ltd., tradename:
E5100). Thereafter, the assembly was cut into a size of 25
mm.times.150 mm to prepare specimens for adhesive strength
measurement. Subsequently, the separation film (SP-PET-03) in the
specimen was separated, and the exposed pressure-sensitive or
bonding adhesive layer 2 was laminated onto a stainless steel plate
(SUS304) by a roller. Thereafter, the adhesive strength (N/25 mm)
to the stainless steel plate surface was measured with a tensile
tester (manufactured by A & D Co., LTD., model: RTF-1150H)
under conditions according to JIS Z 0237 (tensile speed: 300
mm/min, separating distance: 150 mm, separating angle:
180.degree.). The results are shown in Table 3. For the
pressure-sensitive or bonding adhesive sheets of Comparative
Examples 1 to 5 and 7, the measurement could not be carried out,
because the pressure-sensitive or bonding adhesive layer 2 could
not be applied to the stainless steel plate surface.
[0140] In the measurement of the adhesive strength of the
pressure-sensitive or bonding adhesive sheets obtained in Examples
13 to 18, at the outset, the separation film (SP-PET-03) provided
on one pressure-sensitive or bonding adhesive layer 2 in two
pressure-sensitive or bonding adhesive layers provided in the
pressure-sensitive or bonding adhesive sheets was separated, and
the exposed pressure-sensitive or bonding adhesive layer 2 was
applied to a corona-treated surface of a base in the same manner as
described above. Thereafter, the assembly was cut into a size of 25
mm.times.150 mm to prepare specimens for adhesive strength
measurement. Subsequently, the other separation film (SP-PET-03)
was separated from the specimens, and the exposed
pressure-sensitive or bonding adhesive layer 2' was laminated onto
a stainless steel plate (SUS304) by a roller. Thereafter, the
adhesive strength (N/25 mm) to the stainless steel plate surface
was measured using the same tensile tester and measurement
conditions as used above. The results are shown in Table 4. For the
pressure-sensitive or bonding adhesive sheets of Comparative
Examples 8 and 9, the measurement could not be carried out, because
the pressure-sensitive or bonding adhesive layer 2' could not be
applied to the stainless steel plate surface.
[0141] (Measurement of Shearing Strength)
[0142] In the measurement of the shearing strength of the
pressure-sensitive or bonding adhesive sheets obtained in Examples
1 to 12 and Comparative Example 1 to 7, at the outset, the
pressure-sensitive or bonding adhesive sheets were cut into a size
of 25 mm.times.12.5 mm, and one separation film (SP-PET-01) in two
separation films provided on the pressure-sensitive or bonding
adhesive layer in the pressure-sensitive or bonding adhesive sheets
was separated. The exposed pressure-sensitive or bonding adhesive
layer 2 was pressure-bonded to a hot-dip galvanized steel plate
that had been washed with alcohol. Subsequently, the other
separation film (SP-PET-03) was separated, and the exposed
pressure-sensitive or bonding adhesive layer was pressure-bonded to
a hot-dip galvanized steel plate as another specimen.
[0143] When the pressure-sensitive or bonding adhesive sheets of
Examples 1 to 10 and Comparative Examples 1 to 7 were used, samples
for shearing strength measurement were prepared by holding the
sheets at 120.degree. C. for 2 hr in a fan oven while applying a
load of 1 kg for heat curing, allowing the sheets to cool at room
temperature (about 23.degree. C.). On the other hand, when the
pressure-sensitive or bonding adhesive sheets of Examples 11 and 12
were used, an ultraviolet light was applied with an ultraviolet
irradiation apparatus (H bulb, manufactured by Fusion UV Systems
Japan, tradename: DRE-10/12QN) so that the integrated quantity of
light in a wavelength range of 300 to 370 nm was 1000 mJ/cm.sup.2.
Thus, the sheets were cured by ultraviolet irradiation to prepare
samples for shearing strength measurement. Subsequently, for these
samples for measurement, the shearing strength (N/mm.sup.2) stress
at room temperature was measured with a tensile tester
(manufactured by A & D Co., LTD., model: RTA-1T) under
conditions according to JIS K 6850 (tensile speed: 0.5 mm/min). The
results on the pressure-sensitive or bonding adhesive sheets of
Examples 1 to 12 and Comparative Examples 1 to 7 are shown in Table
3.
[0144] In the measurement of the shearing strength of the
pressure-sensitive or bonding adhesive sheets obtained in Examples
13 to 18 and Comparative Example 8 and 9, at the outset, the
pressure-sensitive or bonding adhesive sheets were cut into a size
of 25 mm.times.12.5 mm, and one separation film (SP-PET-03) in two
separation films provided on the pressure-sensitive or bonding
adhesive layer 2 was separated. The exposed pressure-sensitive or
bonding adhesive layer 2 was pressure-bonded to a hot-dip
galvanized steel plate that had been washed with alcohol.
Subsequently, the other separation film (SP-PET-03) provided on the
pressure-sensitive or bonding adhesive layer 2' was separated, and
the exposed pressure-sensitive or bonding adhesive layer 2' was
pressure-bonded to a hot-dip galvanized steel plate as another
specimen.
[0145] When the pressure-sensitive or bonding adhesive sheets of
Examples 13 to 16 and Comparative Examples 8 and 9 were used,
samples for shearing strength measurement were prepared in the same
manner as described above in connection with the use of the
pressure-sensitive or bonding adhesive sheets of Examples 1 to 10
and Comparative Examples 1 to 7. On the other hand, when the
pressure-sensitive or bonding adhesive sheets of Examples 17 and 18
were used, they were cured using the same ultraviolet irradiation
apparatus and curing conditions as described above in connection
with the use of the pressure-sensitive or bonding adhesive sheets
of Examples 11 and 12 to prepare samples for shearing strength
measurement. Subsequently, for these samples for measurement, the
shearing strength (N/mm.sup.2) stress was measured using the same
tensile tester and measuring conditions. The results on the
pressure-sensitive or bonding adhesive sheets obtained in Examples
13 to 18 and Comparative Examples 8 and 9 are shown in Table 4. For
the pressure-sensitive or bonding adhesive sheets of Comparative
Examples 8 and 9, during the measurement of the shearing strength,
separation occurred at the interface of the pressure-sensitive or
bonding adhesive layer 2 and the aramid fiber or at the interface
of the pressure-sensitive or bonding adhesive layer 2' and the
aramid fiber, and, thus, the value at the separation occurred was
regarded as a measured value of the shearing strength.
[0146] (Punching Test and Observation of Separation)
[0147] In a punching test, at the outset, a pressure-sensitive or
bonding adhesive sheet including a repairing or reinforcing sheet
was prepared. In the preparation of the pressure-sensitive or
bonding adhesive sheet, at the outset, a urethane-based
two-component curable adhesive (manufactured by Mitsui Chemicals
Inc., tradename of main agent: Takelac A-310, tradename of curing
agent: Takenate A-3) was coated on one surface of a resin film
(thickness: 15 .mu.m, manufactured by Mitsubishi Plastics, Inc.,
tradename: Supernyl E15) at a coverage of 5 g/m.sup.2 on a solid
basis, and a thermal bond non-woven fabric (basis weight: 23
g/m.sup.2, manufactured by Daio Paper Corporation, tradename:
polyester paper) prepared by a wet process was stacked by dry
lamination. Subsequently, a urethane-based two-component curable
adhesive (manufactured by Mitsui Chemicals Inc., tradename of main
agent: Takelac A-310, tradename of curing agent: Takenate A-3) was
coated on the other surface of the resin film at a coverage of 12
g/m.sup.2 on a solid basis, and a polyethylene terephthalate cloth
(plain weave, fineness: 250 d, applied number of weaving yarns: 43
yarns.times.43 yarns/inch, basis weight: 105 g/m.sup.2) was stacked
by dry lamination. Thus, a repairing or reinforcing sheet was
produced.
[0148] One separation film (SP-PET-01) in two separation films
provided on the pressure-sensitive or bonding adhesive layer 2 in
the pressure-sensitive or bonding adhesive sheets obtained in
Examples 1 to 12 and Comparative Examples 1 to 7 was separated, and
the exposed pressure-sensitive or bonding adhesive layer 2 was
laminated on a polyethylene terephthalate cloth side of the
repairing or reinforcing sheet while heating to 60.degree. C. to
prepare a pressure-sensitive or bonding adhesive sheet including
the repairing or reinforcing sheet. Likewise, the separation film
(SP-PET-03) provided on the pressure-sensitive or bonding adhesive
layer 2' provided on the aramid fiber in the two pressure-sensitive
or bonding adhesive layers provided in the pressure-sensitive or
bonding adhesive sheets obtained in Examples 13 to 18 and
Comparative Examples 8 and 9 was separated. The exposed
pressure-sensitive or bonding adhesive layer 2' was laminated on a
polyethylene terephthalate cloth side of the repairing or
reinforcing sheet under the same conditions as described just above
to prepare a pressure-sensitive or bonding adhesive sheet including
the repairing or reinforcing sheet.
[0149] A product obtained by forming a through-hole at a center of
a U-shaped lid of normal designation "type 1 300" (400 mm.times.600
mm.times.60 mm) specified in JIS A5372 (precast reinforced concrete
product) appendix 5 with a cylindrical core cutter (diameter 100
mm) for concrete was used as an ad herend.
[0150] When the pressure-sensitive or bonding adhesive sheets of
Examples 1 to 10 and Comparative Examples 1 to 7 were used, the
other separation film (SP-PET-03) in the pressure-sensitive or
bonding adhesive sheets including the repairing or reinforcing
sheet was separated. The exposed pressure-sensitive or bonding
adhesive layer 2 was applied in a range of 400 mm.times.600 mm in a
U-shaped lid in an adherend while heating to 120.degree. C. by a
hand roller. Thereafter, the assembly was allowed to stand at room
temperature for 4 days. Likewise, when the pressure-sensitive or
bonding adhesive sheets of Examples 13 to 16 and Comparative
Examples 8 and 9 were used, the separation film (SP-PET-03)
provided on the other pressure-sensitive or bonding adhesive layer
2 in the pressure-sensitive or bonding adhesive sheets including
the repairing or reinforcing sheet was separated. The exposed
pressure-sensitive or bonding adhesive layer 2 was applied to the
adherend under the same conditions described just above, and the
assembly was allowed to stand.
[0151] When the pressure-sensitive or bonding adhesive sheets of
Examples 11 and 12 were used, the other separation film (SP-PET-03)
of the pressure-sensitive or bonding adhesive sheets including the
repairing or reinforcing sheet was separated. The exposed
pressure-sensitive or bonding adhesive layer 2 was applied in a
range of 400 mm.times.600 mm in a U-shaped lid in an adherend by a
hand roller. Thereafter, an ultraviolet light was applied with the
ultraviolet irradiation apparatus used in the shearing strength
measurement so that the integrated quantity of light in a
wavelength range of 300 to 370 nm was 1000 mJ/cm.sup.2, thereby
curing the sheets. Likewise, when the pressure-sensitive or bonding
adhesive sheets of Examples 17 and 18 were used, the separation
film (SP-PET-03) provided the other pressure-sensitive or bonding
adhesive layer 2 in the pressure-sensitive or bonding adhesive
sheet including the repairing or reinforcing sheet was separated.
The exposed pressure-sensitive or bonding adhesive layer 2 was
applied to the adherend under the same conditions as described just
above, followed by curing.
[0152] A load was applied at a speed of 0.2 mm/min in a standard
state (temperature 23.degree. C..+-.2.degree. C., relative humidity
50%.+-.5%) specified in 4 in JIS K6848-1, and, further, a load was
applied at a speed of 1.0 mm/min from a displacement of 2.0 mm to
measure a punching maximum load (kN). The results are shown in
Table 3 and 4. During the measurement, for each displacement of 2.0
mm, the application of the load was stopped for 2 min, and the
separation of the repairing or reinforcing sheet was visually
observed.
[0153] (Measurement of Bond Strength)
[0154] Pressure-sensitive or bonding adhesive sheets including a
repairing or reinforcing sheet that are the same as those prepared
in the punching test were produced. The separation film (SP-PET-03)
provided on the pressure-sensitive or bonding adhesive sheets was
separated, and the exposed pressure-sensitive or bonding adhesive
layer was cured by applying an ultraviolet light from the
pressure-sensitive or bonding adhesive sheet side with the
ultraviolet irradiation apparatus used in the measurement of the
shearing strength so that the integrated quantity of light in a
wavelength range of 300 to 370 nm was 1000 mJ/cm.sup.2. Thereafter,
the pressure-sensitive or bonding adhesive layer side of the sheets
was applied to a 60 mm-thick concrete by a hand roller, and the
assembly was allowed to stand at room temperature for 7 days. The
samples were cut into a size of 40 mm.times.40 mm with a core
cutter for concrete and were evaluated by an exfoliation preventive
property verification test (JHS 424 2004). As a result, all the
pressure-sensitive or bonding adhesive sheets of Example 1 to 3 and
Example 11 to 18 had a bond strength of not less than 1.5
N/mm.sup.2 and a punching strength of not less than 1800 N that
each are on a level that does not pose a practical issue. A failure
in the measurement of the bond strength in the exfoliation
preventive property verification test occurred in the repairing or
reinforcing sheet per se or by an aggregation failure of the
pressure-sensitive or bonding adhesive sheet.
[0155] In the exfoliation preventive property verification test
(JHS 424 2004), at the outset, both surfaces of the sample were
held between two steel attachments (40 mm.times.40 mm) through an
adhesive, and the attachment was bonded and fixed to both surfaces
of the sample. The adhesive spread out from the periphery of the
sample was wiped off, and the assembly as such was allowed to stand
at room temperature for 24 hr. Thereafter, the steel attachment was
mounted on a tensile tester, and a tensile test was carried out,
and a load-displacement curve from the start of the test to the
failure was recorded. The maximum load was determined from the
load-displacement curve, and the bond strength was calculated by
the following equation: S (bond strength: N/mm.sup.2)=P (maximum
load: N)/sample area (area: mm.sup.2).
[0156] (Results)
[0157] The results are shown in Tables 3 and 4. "*" in Tables 3 and
4 indicates that the measurement could not be made because the
pressure-sensitive or bonding adhesive layer could not be applied
to the surface of the stainless steel plate. "Note" in Table 4
indicates that, since separation occurred at the interface of the
pressure-sensitive or bonding adhesive layer 2 and the aramid fiber
or at the interface of the pressure-sensitive or bonding adhesive
layer 2' and the aramid fiber during the measurement of the
shearing strength, the shearing strength when the separation
occurred was regarded as the shearing strength of the
pressure-sensitive or bonding adhesive sheet.
TABLE-US-00005 TABLE 3 Pressure-sensitive Shearing Bond Punching
adhesive force strength strength maximum load (N/25 mm)
(N/mm.sup.2) (N/mm.sup.2) (N) Example 1 0.5 30 2.01 2050 Example 2
0.4 28 2.07 2010 Example 3 2.1 25 2.01 1980 Example 4 0.6 26 --
1970 Example 5 1 28 -- 2060 Example 6 0.8 25 -- 2000 Example 7 3.2
32 -- 2120 Example 8 0.8 31 2100 Example 9 0.9 18 -- 1800 Example
10 1 35 -- 3540 Comparative * 5 -- 800 Example 1 Comparative * 10
-- 850 Example 2 Comparative * 2 -- 700 Example 3 Comparative * 11
-- 1100 Example 4 Comparative * 11 -- 1000 Example 5 Comparative
0.2 13 -- 1300 Example 6 Comparative * 13 -- 1400 Example 7 Example
11 3.5 23 2.1 2200 Example 12 3.2 25 2.2 2150
TABLE-US-00006 TABLE 4 Pressure-sensitive Shearing Bond Punching
adhesive force strength strength maximum load (N/25 mm)
(N/mm.sup.2) (N/mm.sup.2) (N) Example 13 2.1 Not less than 50 2.3
3280 Example 14 3.2 Not less than 50 2.21 3180 Example 15 4.5 Not
less than 50 2.11 3080 Example 16 4.1 Not less than 50 2.21 3640
Comparative * 15 .sup.note) -- 1300 Example 8 Comparative * 18
.sup.note) -- 1300 Example 9 Example 17 5.6 Not less than 50 2.05
3250 Example 18 6.3 Not less than 50 2.11 3120
[0158] From the results of Tables 3 and 4, it was found that the
pressure-sensitive or bonding adhesive sheets of Examples 1 to 18
had a pressure-sensitive adhesive strength of not less than 0.3
N/25 mm and a shearing strength of not less than 18 MPa and the
pressure-sensitive or bonding adhesive layer had a
pressure-sensitive adhesive strength and a high adhesive strength.
Further, the pressure-sensitive or bonding adhesive sheets of
Examples 1 to 18 had a punching maximum load of not less than 1800
N and could repair and reinforce concrete with a high strength. As
a result of observation on the separation of the repairing or
reinforcing sheet, it was found that, when the pressure-sensitive
or bonding adhesive sheets of Examples 1 to 18 were used, no
separation occurred, whereas, when the pressure-sensitive or
bonding adhesive sheets of Comparative Examples 1 to 7 were used,
separation occurred. For Comparative Examples 8 and 9, the adhesion
to the aramid fiber was so poor that the bond strength was not
satisfactory.
[0159] In Examples 1 to 18, the content of the acrylic resin in the
pressure-sensitive or bonding adhesive layer was 4.76% by mass to
50.0% by mass, and it was confirmed that good results could be
obtained in this content range. Further, it was confirmed that
particularly good results could be obtained in an acrylic resin
content range of 4.76% by mass to 33.4% by mass.
[0160] For the pressure-sensitive or bonding adhesive sheets of
Examples 13 to 18, even immediately after the application of
concrete to one pressure-sensitive or bonding adhesive layer 2 in
the two pressure-sensitive or bonding adhesive layers in the
pressure-sensitive or bonding adhesive sheets of Examples 13 to 18,
the surface of the other pressure-sensitive or bonding adhesive
layer 2' was hardly influenced by irregularities of the aramid
fiber and the concrete and was flat and smooth.
DESCRIPTION OF REFERENCE CHARACTERS
[0161] 1,1' Separation film [0162] 2,2' Pressure-sensitive or
bonding adhesive layer [0163] 3 Repairing or reinforcing sheet
[0164] 10,10A to 10G Pressure-sensitive or bonding adhesive sheet
[0165] S1,S2,S1',S2' Surface of pressure-sensitive or bonding
adhesive layer
* * * * *