U.S. patent application number 11/720146 was filed with the patent office on 2008-09-18 for water-soluble film roll and method for paying out water-soluble film.
This patent application is currently assigned to KURARAY CO., LTD.. Invention is credited to Shintaro Hikasa, Naohiro Hosoda.
Application Number | 20080226919 11/720146 |
Document ID | / |
Family ID | 36497889 |
Filed Date | 2008-09-18 |
United States Patent
Application |
20080226919 |
Kind Code |
A1 |
Hosoda; Naohiro ; et
al. |
September 18, 2008 |
Water-Soluble Film Roll and Method for Paying Out Water-Soluble
Film
Abstract
To provide a water-soluble film roll 3 having end faces 4 with
masking materials 5 adhered thereto. By using the water-soluble
film roll 3 and paying out a water-soluble film 1 while holding the
masking materials 5 adhered to the end faces 4, it is possible to
prevent moisture from adhering to the end faces 4 and to prevent
the water-soluble film 1 from rupturing due to welding of the film
1 with itself. In this connection, the masking materials 5 are
preferably a plastic film capable of being adhered to the end faces
4 with a pressure-sensitive adhesive.
Inventors: |
Hosoda; Naohiro; (Ehime,
JP) ; Hikasa; Shintaro; (Okayama, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
KURARAY CO., LTD.
Okayama
JP
|
Family ID: |
36497889 |
Appl. No.: |
11/720146 |
Filed: |
November 7, 2005 |
PCT Filed: |
November 7, 2005 |
PCT NO: |
PCT/JP05/20358 |
371 Date: |
May 24, 2007 |
Current U.S.
Class: |
428/411.1 ;
242/348; 428/220; 428/36.6 |
Current CPC
Class: |
C08J 5/18 20130101; Y10T
428/1379 20150115; B65D 85/672 20130101; C08J 2329/04 20130101;
Y10T 428/31504 20150401 |
Class at
Publication: |
428/411.1 ;
428/220; 428/36.6; 242/348 |
International
Class: |
B32B 27/00 20060101
B32B027/00; G11B 23/107 20060101 G11B023/107 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2004 |
JP |
2004-339083 |
Claims
1. A water-soluble film roll, wherein a masking material is adhered
to an end face of a roll of a water-soluble film.
2. The water-soluble film roll according to claim 1, wherein the
water-soluble film is a polyvinyl alcohol film.
3. The water-soluble film roll according to claim 1, wherein the
water-soluble film has a thickness of 10 to 200 .mu.m.
4. The water-soluble film roll according to claim 1, wherein the
water-soluble film has a water content of 1 to 6% by weight.
5. The water-soluble film roll according to claim 1, herein the
water-soluble film has a Young's modulus of 50 to 500 MPa.
6. The water-soluble film roll according to claim 1, herein the
masking material is adhered with a pressure-sensitive adhesive.
7. The water-soluble film roll according to claim 6, wherein the
pressure-sensitive adhesive has an adhesion of 0.01 to 5 N/cm.
8. The water-soluble film roll according to claim 1, wherein the
masking material is composed of a plastic film.
9. The water-soluble film roll according to claim 1, wherein the
water-soluble film is a hydraulic transfer base film.
10. A package comprising the water-soluble film roll according to
claim 1, in a moisture-proof package.
11. A method for paying out a water-soluble film, the method
comprising paying out the water-soluble film from the water-soluble
film roll according to claim 1 while the masking material is held
adhered to the end face of the water-soluble film roll.
12. The method for paving out a water-soluble film according to
claim 11, wherein the paying out speed is 1 to 100 m/min.
13. A method for producing a printed film, the method comprising
applying print to a water-soluble film while paying out the
water-soluble film by the method according to claim 11.
Description
TECHNICAL FIELD
[0001] The present invention relates to a water-soluble film roll,
and particularly to a water-soluble film roll having end faces with
masking materials adhered thereto. The invention also relates to a
method for paying out a water-soluble film from the water-soluble
film roll.
BACKGROUND ART
[0002] Water-soluble films made of polyvinyl alcohol or the like
are used for various applications. Examples of such films include
hydraulic transfer base films which are to be used for hydraulic
transfer method. The hydraulic transfer method is a process in
which a printed film for hydraulic transfer, which includes a
water-soluble hydraulic transfer base film having on a surface
thereof a print layer to be transferred, is floated on the surface
of water with its print side up and then various types of shaped
articles, which are transfer receptors, are pushed downward into
the printed film; thereby the print layer is transferred to the
transfer receptors due to hydraulic pressure (see, for example,
patent reference 1). Using the hydraulic transfer method, it is
possible to impart design to the surface of a shaped article having
an uneven three-dimensional surface or a curved surface or to form
a print layer for the purpose of improving surface properties.
[0003] In many cases, a water-soluble film produced is wound up
into a roll to form a water-soluble film roll. The water-soluble
film roll is packed up and then transported to a
secondary-processing manufacturer or the like. The water-soluble
film roll, which has been unpacked there, is then installed to a
paying out machine and is subjected to secondary processing, such
as printing.
[0004] In application of secondary processing, particularly of
high-speed printing, occurrence of film rupture during the paying
out of a film from a roll thereof has become a problem. In a
processing line of a continuous system, production loss is caused
mainly by rupture of a film because it takes a long time to
reintroduce a film to a processing machine. Rupture of a film may
occur throughout a year, but it occurs particularly frequently in
winter.
[0005] It has heretofore been believed that occurrence of film
rupture is greatly influenced by moisture. Therefore, approaches of
packing or wrapping of water-soluble film rolls sufficiently have
been adopted. In many cases, however, it is impossible to avoid
occurrence of rupture of a film during the paying out thereof no
matter how the packing or wrapping thereof is sufficient.
[0006] Meanwhile, it has been believed that the reason why rupture
of a film occurs particularly frequently in winter is that tear
strength of a film decreases when the temperature of the film is
low. Therefore, a countermeasure is taken which includes use, in
winter, of a water-soluble film softened through adjustment of the
composition of the base resin of the film. Nobody, however, has
exterminated rupture of films.
[0007] Patent Document 1: JP 54-33115 A
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0008] The present invention was made in order to solve the
problems mentioned above. An object of the present invention is to
provide a water-soluble film roll which can prevent a film from
rupturing when the film is paid out from the roll. Another object
is to provide a method for paying out a water-soluble film by which
the film is prevented from rupturing.
Means for Solving the Problems
[0009] As a result of intensive researches on techniques for
attaining the above-mentioned objects the present inventors found
that rupture of a water-soluble film during the paying out of its
roll is caused by permeation of moisture from the end faces of the
roll and that the above-mentioned problem can be solved by
provision of a water-soluble film roll in which a masking material
is adhered to an end faces of the water-soluble film roll.
[0010] Under some circumstances where a water-soluble film roll is
placed in, for example, its unpackaging, moisture may adhere to the
surface of the roll. For example, dew condensation may occur on the
surface of a roll, or mist-like waterdrops floating in the air may
adhere to the surface of a roll. Dew condensation tends to occur
when the temperature of the surface of a roll is lower than the
indoor temperature, for example, when a cooled water-soluble film
roll is carried into a warm room. The adhering of mist-like
waterdrops tends to occur in rooms humidified with a humidifier or
the like. When humidification is performed with a humidifier or the
like, mist-like waterdrops are formed through condensation of the
steam released from the humidifier due to the temperature
distribution in the room. The waterdrops move along the air flow
and adhere to a roll. Alternatively, mist-like waterdrops directly
released from a humidifier or the like adhere to a roll.
[0011] Thus, once moisture adheres to the surface of a
water-soluble film roll, especially an end face of the roll, the
moisture permeates from the end portion of the roll and immediately
spreads into a gap of the water-soluble film. The moisture swells
and dissolves the surface of the film and simultaneously further
permeates into the inside of the film and is dried again. Thus,
local welding is caused between portions of the water-soluble film
in contact. It was found that such welding of a film itself causes
rupture of the film during the paying out of the film from a roll
thereof. A conceivable reason why such rupture of a film occurs
particularly frequently in winter is not only that the tear
strength of a film decreases, but also that the temperature of the
surface of a roll drops during transportation or the like and,
therefore, dew condensation readily occurs or that the inside of a
room is often humidified.
[0012] Even when the packing or wrapping of a roll is sufficient,
it is a common knowledge that the roll is loaded to a paying-out
machine after being unpackaged or unwrapped. Generally, it takes
several tens of minutes or more from the completion of the loading
to a paying-out machine to the completion of the paying out.
However, once moisture adheres to an end face of the roll during
that time, the film will result in welding in a short time after
the adhesion of the moisture while depending on the kind of the
film and conditions such as temperature and humidity. As mentioned
above, welding of a film can occur even during the paying out of
the film. Thus, finding that it is necessary to prevent moisture
permeation even during paying out resulted in the present
invention.
[0013] It is desirable that the water-soluble film is a polyvinyl
alcohol film. It is desirable that the water-soluble film has a
thickness of 10 to 200 .mu.m, that the water-soluble film has a
water content of 1 to 6% by weight, and that the water-soluble film
has a Young's modulus of 50 to 500 MPa. It is desirable that the
masking material is adhered with a pressure-sensitive adhesive. In
this connection, it is more desirable that the pressure-sensitive
adhesive has an adhesion of 0.01 to 5 N/cm. It is also desirable
that the masking material is composed of a plastic film. It is also
desirable that the water-soluble film is a hydraulic transfer base
film. Moreover, a package comprising the aforementioned
water-soluble film roll in a moisture-proof package is also
preferable.
[0014] One preferred embodiment is a method for paying out a
water-soluble film, the method comprising paying out a
water-soluble film from a water-soluble film roll while holding the
masking material is held adhered to the end face of the
water-soluble film roll. In this connection, it is desirable that
the paying out speed is 1 to 100 m/min. Another preferred
embodiment is a method for producing a printed film, the method
comprising applying print to a water-soluble film while paying out
the water-soluble film by the method mentioned above.
EFFECT OF THE INVENTION
[0015] Use of the water-soluble film roll of the present invention
makes it possible to prevent moisture from permeating from the end
faces of the water-soluble film roll. As a result it is possible to
effectively prevent a water-soluble film from rupture thereof which
occurs in the course of the paying out of the water-soluble film
from a water-soluble film roll, regardless of the circumstance
where the water-soluble film roll is placed. Particular suitability
is found in the case where the water-soluble film is a hydraulic
transfer base film.
BRIEF DESCRIPTION OF THE DRAWING
[0016] FIG. 1 is a diagram showing the water-soluble film roll of
Example 1.
EXPLANATION OF REFERENCE NUMERALS
[0017] 1 Water-soluble film [0018] 2 Paper tube [0019] 3
Water-soluble film roll [0020] 4 End face [0021] 5 Masking
material
BEST MODE FOR CARRYING OUT THE INVENTION
[0022] The water-soluble film roll of the present invention is a
water-soluble film roll wherein a masking material is adhered to an
end face of the roll of a water-soluble film.
[0023] The water-soluble film mentioned above is not particularly
restricted as long as it is water-soluble and examples thereof
include water-soluble films of one resin or two ore more resins
selected from polyvinyl alcohol, carboxymethylcellulose,
hydroxyethylcellulose, polyvinylpyrrolidone, polyacrylic acid and
salts thereof starch, glycerol gelatin and the like. In particular
water-soluble films made of polyvinyl alcohol are preferably used
because it is possible to control mechanical strength required and
moisture resistance during handling by changing various conditions
such as degree of polymerization and degree of saponification of
polyvinyl alcohol, incorporation of additives such as starch.
Water-soluble films made of polyvinyl alcohol are of good
printability. In addition, the speed of softening due to water
absorption after being floated on water, the time necessary for
spreading or diffusing and the easiness of deformation during
transfer can be controlled. Therefore, they are suitably used as
hydraulic transfer base films. The higher the water solubility of
the aforesaid water-soluble film, the more noticeably the effect of
the present invention is exhibited.
[0024] It is desirable that the thickness of the aforesaid
water-soluble film is from 10 to 200 .mu.m. When the thickness is
less than 10 .mu.m, the film is lacking strength and, therefore the
process passability of the water-soluble film in its secondary
processing may be deteriorated. The thickness is more preferably 20
.mu.m or more, and even more preferably 25 .mu.m or more. When the
thickness is over 200 .mu.m, the water-soluble film becomes more
resistant to rupture due to increase in strength of the film and,
therefore, the necessity for adopting the Constitution of the
present invention decreases. In use as a hydraulic transfer base
film, the solubility in water decreases and, as a result the
production efficiency by the hydraulic transfer method may be
reduced. The thickness is more preferably 10 .mu.m or less, and
even more preferably 40 .mu.m or less.
[0025] It is desirable that the water content of the aforesaid
water soluble film is from 1 to 6% by weight. When the water
content is less than 1% by weight, not only the film tends to
rupture due to reduction in its impact resistance, but also the
film tends to have static electricity and, therefore, dust or dirt
may adhere to the film. As a result, for example, when printing is
applied to the film, print omission may occur. The water content is
more preferably 1.5% by weight or more, and even more preferably 2%
by weight or more. When over 6% by weight, the film may be
stretched during paying out of the film from a water-soluble film
roll. As a result, when printing is applied to the film, print
patterns may lose sharpness, or when multicolor printing is
applied, print shift may occur. The water content is more
preferably 4% by weight or less.
[0026] It is desirable that the Young's modulus of the aforesaid
water-soluble film is from 50 to 500 MPa. The Young's modulus of a
water-soluble film as used herein means a Young's modulus of the
film in the winding-up direction (MD) thereof measured by the
method described below When the Young's modulus is less than 50
MPa, the impact resistance is high and the film is resistant to
rupture during its paying out even when welding of the film occurs
and, therefore, the necessity for adopting the constitution of the
present invention may decrease. When a water-soluble film is paid
out, the film may be stretched in its longitudinal direction and,
therefore, print patterns may lose sharpness when printing is
applied. The Young's modulus is more preferably 100 MPa or more. On
the other hand, when the Young's modulus is over 500 MPa, the
impact resistance decreases and the film tends to rupture. The
Young's modulus is more preferably 300 MPa or less. In the
measurement of the Young's modulus, a sample film having been cut
into a strip form of 15 mm in width and 150 mm in length was
humidity controlled under conditions of 20.degree. C. and 65% RH
for 3 hours and then stretched with an Autograph (manufactured by
Shimadzu Corp.) at a chuck distance of 100 mm and a tension rate of
100 mm/min. Then, an elastic modulus was calculated from the load
at an elongation of 2%.
[0027] The aforesaid water-soluble film is wound into the form of a
roll and results in a water-soluble film roll. The water-soluble
film roll may either be wound around a core or be directly wound
without using a core. In consideration of the workability of paying
out the film, it is preferable that the water-soluble film roll is
wound around a core. In this connection, it is more preferable that
the water-soluble film roll is wound around a cylindrical core. The
material of the core is not particularly restricted, but paper
plastic, and the like are typically used. There are no particular
restrictions in length and width of the water-soluble film. Films
with a length of from about 1 to about 3000 m and a width of from
about 0.5 to about 4 m are preferably used.
[0028] On an end face of the water-soluble film roll of the present
invention, a masking material must be adhered. If the masking
material is only in contact with the end face, water permeates
through a small gap between the end face of the roll and the
masking material during paying out of the film, resulting in
rupture of the film. When the masking material is adhered to the
end face and rotates as a unit together with the roll, the
permeation of moisture is prevented completely. The method by which
the masking material is adhered is not particularly restricted, but
it is preferably adhered with a pressure-sensitive adhesive. For
example, a masking material having a pressure-sensitive adhesive
layer is suitably used.
[0029] The pressure-sensitive adhesive as referred to herein is a
substance which can be adhered to an object by pressing.
Pressure-sensitive adhesives which can be used are not particularly
restricted and examples thereof include rubber-based
pressure-sensitive adhesives, acryl-based pressure-sensitive
adhesives and ethylene vinyl acetate (EVA)-based pressure-sensitive
adhesives. The aforesaid pressure-sensitive adhesive is preferably
non-solvent type one because it is desirable that components of a
pressure-sensitive adhesive is difficult to migrate to a
water-soluble film even in close contact for a long period of time.
It is desirable that the pressure-sensitive adhesive have an
adhesion of from 0.01 to 5 N/cm. The adhesion of a
pressure-sensitive adhesive as referred to herein is an adhesion
measured in accordance with JIS Z0237. When the adhesion was 0.1
N/cm or more, a stainless steel plate was used as a test plate to
which a masking material is adhered. When the adhesion was less
than 0.1 N/cm, an acrylic resin (PMMA) plate was used as a test
plate to which a masking material is adhered.
[0030] The adhesion of the pressure-sensitive adhesive is
preferably 0.01 N/cm or more, and more preferably 0.1 N/cm or more
because a masking material is required to remain adhered on an end
face of a water-soluble film roll without being detached even
during the paying out of a water-soluble film from the
water-soluble film roll. On the other hand, when the adhesion of
the pressure-sensitive adhesive is too high, the end face of the
water-soluble film roll may get coarse or some portion of the
adhesive may stay on the end face, or the water-soluble film may
rupture due to adhesion resistance with the pressure-sensitive
adhesive. From this point of view, the adhesion of the
pressure-sensitive adhesive is preferably 5 N/cm or less, and more
preferably 2 N/cm or less. Therefore, from the viewpoint of
preventing these problems, the pressure-sensitive adhesive is
desirably one having not too high an adhesion. It is also desirable
that the pressure-sensitive adhesive has removability. Synthetic
rubber-based or ethylene-vinyl acetate-based pressure-sensitive
adhesives are more suitably used because they are of non-solvent
type and also because it is easy to select one having a proper
adhesion. Plastic films of resin having pressure-sensitive
adhesiveness are also used.
[0031] While the above-mentioned masking material is normally
composed of plastic film, paper, plate, nonwoven fabric, woven
fabric or knit, it is not particularly restricted. From the
viewpoint of effective prevention of moisture permeation, the
masking material is preferred to be of flexibility sufficient for
following unevenness of an end face of a water-soluble film roll
and to be water-impermeable. For this reason, the masking material
is preferably made of plastic film. While examples of such plastic
film include films of polyester, polyolefin, polyvinyl chloride,
cellophane or acetate, films of polyolefin are preferably used from
the flexibility point of view.
[0032] A package including the aforementioned water-soluble film
roll in a moisture-proof package is a preferred embodiment. Many
water-soluble films are highly hygroscopic. Therefore, when a
water-soluble film roll is allowed to stand for a long period of
time while being unpackaged, the film may absorb moisture in the
air, and surface film and film located at the ends of the roll may
stretch to form wrinkles or slack. It is possible to prevent these
problems by packaging a water-soluble film roll in a moisture-proof
package.
[0033] While the method of moisture-proof packaging is not
particularly restricted, it is preferable to cover a water-soluble
film roll with a moisture-proof film such as aluminum deposit film.
It may, if needed, be covered further with kraft paper or the like.
In order to prevent a roll from being damaged due to shocks during
transportation, it is desirable to mount hanging holders to both
ends of the core of the roll and package the roll while hanging
it.
[0034] Examples of the application of the water-soluble film
include unit packaging materials for packaging a unit amount of
agricultural chemicals, detergents, paints, and the like,
remoistening adhesives, temporary supports such as embroidery bases
or wig bases, agricultural seed tapes and seed cultivation sheets,
laundry bags, textile packaging materials and hydraulic transfer
base films. Among these, hydraulic transfer base films are
preferred. Use of the present invention is greatly beneficial for
hydraulic transfer base films because such films are often paid out
continuously at a high speed for a long period of time when
printing is applied thereto and, therefore rupture of a film due to
welding easily occur.
[0035] A method for paying out a water-soluble film wherein a
water-soluble film is paid out from the aforesaid water-soluble
film roll while the masking materials are held adhered to the end
faces of the water-soluble film roll is a preferable embodiment of
the present invention. By paying out a water-soluble film in such a
state, it is possible to prevent the water-soluble film from
welding caused by permeation of moisture from the end faces of the
water-soluble film roll even during the paying out of the roll. As
a result, rupture of the water-soluble film can be prevented
effectively.
[0036] In this connection, it is desirable that the paying out
speed of a water-soluble film is from 1 to 100 m/min. When it is 1
m/min or less, the production efficiency in secondary processing
decreases, and in addition, the need for adopting the constitution
of the present invention is reduced because rupture of a
water-soluble film due to welding rarely occurs. The paying out
speed is more preferably 10 m/min or more, and even more preferably
20 m/min or more. When the speed is over 100 m/min, rupture of a
film will occur easily. Moreover, the quality may not be
sufficiently maintained when a film is printed. The paying out
speed is more preferably 80 m/min or less, and even more preferably
60 m/min or less.
[0037] While the masking materials are required to be kept adhered
to the end faces of the water-soluble film roll during the paying
out of the water-soluble film from the water-soluble film roll, the
timing when the masking materials are adhered to the end faces is
not particularly restricted. For example, it may be adhered
immediately after a water-soluble film roll is produced.
Alternatively, it may also be adhered after a water-soluble film
roll is taken out from a moisture-proof package. In order to
prevent rupture of a water-soluble film effectively, it is
desirable to adhere so that the period of time when the end faces
of a water-soluble film roll are left exposed may become as short
as possible.
[0038] A method for producing a printed film in which printing is
applied to a water-soluble film while the water-soluble film is
paid out by the aforementioned method for paying out a
water-soluble film is also a preferred embodiment. During the
production of a printed film, a water-soluble film is often
required to be paid out continuously at a high speed for a long
period of time and rupture caused by welding of the water-soluble
film tends to occur. Therefore, the benefit from the adoption of
the paying out method described above is great. The printing to a
water-soluble film is performed by a conventional method. For
example, gravure printing, screen printing, offset printing, roll
coating, and the like are adopted. A method in which printing is
applied directly to a water-soluble film and a method in which
printing is applied to another film temporarily and then
transferred to a water-soluble film are available. The ink used for
the printing is not particularly restricted and conventional inks
may be used.
[0039] The printed film prepared by the production method described
above can be used suitably in a hydraulic transfer method as a
printed film for hydraulic transfer in which a print layer has been
formed on a water-soluble film. Print layers on water-soluble films
are normally water-insoluble and, end portions of a film where no
print layer has been formed are often cut away after printing. In
many cases, therefore, at end portions of a roll of a wound printed
film for hydraulic transfer, a water-soluble film is not in direct
contact with itself. For this reason, when a printed film for
hydraulic transfer is paid out again from such a roll, the film
will hardly be welded with itself. Therefore, it becomes
unnecessary to provide a roll of a printed film for hydraulic
transfer with masking materials for preventing rupture of the
film.
[0040] The above-mentioned printed film for hydraulic transfer is
used for forming a print layer on the surfaces of various shaped
articles and the like. The surfaces of the shaped articles and the
like may be flat, rough or uneven. The film can suitably be used
mainly for forming a print layer on the surface of a shaped article
having an uneven three-dimensional surface or a curved surface.
EXAMPLES
[0041] The present invention is described concretely below with
reference to Examples. It is noted that each of the water-soluble
film rolls used in Examples was stored in a moisture-proof package
at room temperature, 20 to 25.degree. C., until immediately before
a masking material was adhered to an end face of a roll.
Example 1
[0042] As shown in FIG. 1, to each of both end faces 4 of a
water-soluble film roll 3 prepared by winding up a polyvinyl
alcohol film (VF-H Series manufactured by Kuraray Co., Ltd.,
thickness: 30 .mu.m, width: 300 mm, length: 1000 m, water content:
2.8%, Young's modulus: 200 MPa), which is a water-soluble film 1,
around a paper tube 2 (paper cylinder with an inner diameter of 75
mm and an outer diameter of 90 mm), a "protect tape #6314-B"
(polyolefin film having a special synthetic rubber-based
pressure-sensitive adhesive layer on one side; overall thickness:
60 .mu.m, adhesion: 0.9 N/cm) manufactured by Sekisui Chemical Co.,
Ltd., which had been cut into a doughnut shape in conformity with
the outer diameter of the paper tube 2 and the winding diameter of
the water-soluble film roll 3, as a masking material 5, was adhered
with avoidance of air bubble formation. In a room
humidification-conditioned to a temperature of 20.degree. C. and a
relative humidity of 60% from the outdoor conditions, i.e. a
temperature of 10.degree. C. and a relative humidity of 50%, the
water-soluble film roll 3 was loaded into a paying-out machine. The
polyvinyl alcohol film was then continuously paid out from the
water-soluble film roll 3 at a rate of 30 m/min and printing was
applied to one side of the water-soluble film 1. In this operation,
the generation of peeling sound of the polyvinyl alcohol film at
the end portions of the water-soluble film roll 3 was checked and
the number of ruptures of the polyvinyl alcohol film was counted.
When this evaluation procedure was repeated for five rolls, none of
the five rolls generated peeling sound or rupture. The results are
summarized in Table 1.
Example 2
[0043] Operations the same as those in Example 1 were repeated
except using as masking materials 5, "protect tape #622-B"
(polyolefin film having an ethylene vinyl acetate (EVA)-based
pressure-sensitive adhesive layer on one side; overall thickness:
55 .mu.m adhesion: 0.02 N/cm) manufactured by Sekisui Chemical Co.
Ltd. which had been cut into a doughnut shape in conformity with
the outer diameter of the paper tube 2 and the winding diameter of
the water-soluble film roll 3. In this operation, the generation of
peeling sound of the polyvinyl alcohol film at the end portions of
the water-soluble film roll 3 was checked and the number of
ruptures of the polyvinyl alcohol film was counted. When this
evaluation procedure was repeated for five rolls, no peeling sound
and no rupture were generated in three rolls. In two rolls,
however, the polyvinyl alcohol films peeled off partly from the end
faces 4 of the rolls and came to produce peeling sound during the
paying out of the films. In addition, each film ruptured only once.
Therefore, the number of ruptures was 0.4 times per roll in
average. The results are summarized in Table 1.
Example 3
[0044] Operations the same as those in Example 1 were repeated
except using, as masking materials 5, "Elep masking tape N-300"
(polyester film having an acryl-based pressure-sensitive adhesive
layer on one side; overall thickness: 100 .mu.m, adhesion: 2.8
N/cm) manufactured by Nitto Denko Corp. in this operation, the
generation of peeling sound of the polyvinyl alcohol film at the
end portions of the water-soluble film roll 3 was checked and the
number of ruptures of the polyvinyl alcohol film was counted. The
results of evaluations for only one roll are summarized in Table
1
Comparative Example 1
[0045] Operations the same as those of Example 1 were repeated
except using no masking material 5. In this operation, the
generation of peeling sound of the polyvinyl alcohol film at the
end portions of the water-soluble film roll 3 was checked and the
number of ruptures of the polyvinyl alcohol film was counted. The
results of evaluations for only one roll are summarized in Table
1.
Comparative Example 2
[0046] Operations the same as those of Example 1 were repeated
except using corrugated cardboards (thickness: 2 .mu.m) as masking
materials 5 and bringing them into close contact with the end faces
4 of a roll without using pressure-sensitive adhesive. In this
operation, the generation of peeling sound of the polyvinyl alcohol
film at the end portions of the water-soluble film roll 3 was
checked and the number of ruptures of the polyvinyl alcohol film
was counted. The results of evaluations for only one roll are
summarized in Table 1.
TABLE-US-00001 TABLE 1 Gener- ation Number of Constitution of
Adhesion of peeling ruptures masking material (N/cm) sound (time)
Example 1 Polyolefin film 0.9 No 0 having a special synthetic
rubber-based pressure-sensitive adhesive layer on one side Example
2 Polyolefin film 0.02 Yes/ 0.4 having an EVA-based No *1)
pressure-sensitive adhesive layer on one side Example 3 Polyester
film 2.8 Yes 0 having an acryl-based pressure-sensitive adhesive
layer on one side Comparative None -- Yes 10 Example 1 Comparative
Corrugates -- Yes 2 Example 2 cardboard *1) Peeling sounds were
generated in two of the five rolls.
[0047] As shown in Table 1, when masking materials 5 with an
adhesion of 0.9 N/cm were adhered to end faces 4 of a water-soluble
film roll 3 (Example 1), no peeling sounds were generated and no
rupture of a polyvinyl alcohol film occurred in all of the five
rolls tested. When low-bonding masking materials 5 with an adhesion
of 0.02 N/cm were adhered to end faces 4 of a water-soluble film
roll 3 (Example 2), in two of the five rolls tested, a peeling
sound was generated and rupture occurred only once in each roll. In
the remaining three rolls, however no peeling sound was generated
and no rupture occurred. When high-bonding masking materials 5 with
an adhesion of 2.8 N/cm were adhered to end faces 4 of a
water-soluble film roll 3 (Example 3), peeling sounds were
generated, but no rupture of a polyvinyl alcohol film occurred. The
peeling sounds seem to be sounds generated when the polyvinyl
alcohol film and the adhesive on the masking materials 5 peel off
from each other. When no masking material 5 was used (Comparative
Example 1), peeling sounds due to welding of the polyvinyl alcohol
film were generated and rupture of the polyvinyl alcohol film
frequently occurred. When corrugated cardboards were used as
masking materials 5 and they were brought into close contact with
end faces 4 of a water-soluble film roll 3 (Comparative Example 2),
many peeling sounds due to welding of the polyvinyl alcohol film
were generated in an early stage of the paying out, and rupture of
the polyvinyl alcohol film occurred at the outer peripheral
portions of the water-soluble film roll 3. It is assumed that
permeation of moisture was not prevented at the outer peripheral
portions of the end faces 4 of the water-soluble film roll 3
leading to welding of the polyvinyl alcohol film and resulting in
occurrence of the rupture.
* * * * *