U.S. patent application number 10/499974 was filed with the patent office on 2005-02-10 for resin composition, and container packaging film, container packaging bag and container package using the resin composition.
Invention is credited to Kageyama, Yohei, Kotani, Masataka.
Application Number | 20050031815 10/499974 |
Document ID | / |
Family ID | 27348027 |
Filed Date | 2005-02-10 |
United States Patent
Application |
20050031815 |
Kind Code |
A1 |
Kageyama, Yohei ; et
al. |
February 10, 2005 |
Resin composition, and container packaging film, container
packaging bag and container package using the resin composition
Abstract
The present invention is aimed to provide a resin composition
suitable for a container packaging film that has excellent
appearance and antiblocking properties, and has no fear of
contamination into the container. The present invention relates to
resin composition comprising from 40 to 90 mass % of a
propylene-base polymer and from 10 to 60 mass % of a high-density
polyethylene (the total of the propylene-base polymer and the
high-density polyethylene is 100 mass %), the composition
substantially not containing a lubricant and not containing an
antiblocking agent, and the ratio of MFR of the propylene-base
polymer at 230.degree. C. to MFR of the high-density polyethylene
at 190.degree. C. being from 5 to 200. The present invention also
relates to a container packaging film, sealant film, laminate,
container packaging bag, and container package using the resin
composition of the present invention.
Inventors: |
Kageyama, Yohei;
(Chigasaki-shi, JP) ; Kotani, Masataka;
(Yokohama-shi, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Family ID: |
27348027 |
Appl. No.: |
10/499974 |
Filed: |
June 24, 2004 |
PCT Filed: |
December 25, 2002 |
PCT NO: |
PCT/JP02/13500 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60350030 |
Jan 23, 2002 |
|
|
|
Current U.S.
Class: |
428/35.7 |
Current CPC
Class: |
C08L 23/10 20130101;
C08L 23/142 20130101; C09J 123/142 20130101; C08L 23/16 20130101;
C08L 2666/06 20130101; C08L 2666/06 20130101; C08L 2666/06
20130101; C08L 2666/06 20130101; C08L 2666/06 20130101; C08L 23/06
20130101; C09J 123/06 20130101; C09J 123/06 20130101; C08J 2323/06
20130101; C08L 23/142 20130101; B32B 27/32 20130101; C08L 2666/06
20130101; C08L 23/06 20130101; C08J 2323/14 20130101; C09J 123/142
20130101; C08J 5/18 20130101; Y10T 428/1352 20150115; C08L 23/10
20130101 |
Class at
Publication: |
428/035.7 |
International
Class: |
B65D 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 27, 2001 |
JP |
2001-397606 |
Nov 19, 2002 |
JP |
2002-335008 |
Claims
1. (Cancelled)
2. A container packaging film made from: (a) a sealant layer made
from a composition comprising a propylene-base polymer and a
high-density polyethylene, and substantially not containing a
lubricant and not containing an antiblocking agent, and (b) a
support layer made from propylene-ethylene block copolymer; said
container packaging film having the coefficient of kinetic friction
between the container packaging films after high pressure steam
sterilization at 125.degree. C. for 30 min. being 0.4 or less.
3. A container packaging film as claimed in claim 2, wherein said
composition comprises from 40 to 90 mass % of a propylene-base
polymer and from 10 to 60 mass % of a high-density polyethylene
(the total of the propylene-base polymer and the high-density
polyethylene constitute 100 mass %), the ratio of MFR of the
propylene-base polymer at 230.degree. C. to MFR of the high-density
polyethylene at 190.degree. C. being from 5 to 200.
4. (Cancelled)
5. A laminate comprising a layer composed of the container
packaging film claimed in claim 2 or 3, and at least one layer
selected from the group consisting of a gas barrier layer, a
printing layer and a protective layer.
6. A container packaging bag comprising a container packaging film
according to claim 2 or 3, wherein the surface of the film coming
into contact with a container is the sealant layer of the container
packaging film.
7. A container package, wherein a container is housed in the
container packaging bag claimed in claim 6 and is subjected to
high-pressure steam sterilization.
8. The container package as claimed in claim 7, wherein the
high-pressure steam sterilization temperature is 121.degree. C. or
more.
9. The container package as claimed in claim 7, wherein the
container is a medical container.
10. The container package as claimed in claim 9, wherein the outer
surface of the container, coming into contact with the container
packaging bag is composed of a propylene-based polymer.
11. The container package as claimed in claim 7, wherein the inside
of the container package is depressurized.
12. The container package as claimed in claim 11, wherein the
container is a medical container.
13. The container package as claimed in claim 11, wherein the outer
surface of the container coming into contact with the container
packaging bag is composed of a propylene-base polymer.
14. The container package as claimed in claim 8, wherein the
container is a medical container.
15. The container package as claimed in claim 14, wherein the outer
surface of the container coming into contact with the container
packaging bag is composed of a propylene-based polymer.
16. The container package as claimed in claim 8, wherein the inside
of the container package is depressurized.
17. The container package as claimed in claim 16, wherein the
container is a medical container.
18. The container package as claimed in claim 16, wherein the outer
surface of the container coming into contact with the container
packaging bag is composed of a propylene-base polymer.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit pursuant to 35 U.S.C.
119(e)(1) of U.S. Provisional Application, No. 60/350,030 filed
Jan. 23, 2002; and the benefit pursuant to the priority of the
Paris Convention of Japanese Patent Applications, JP-2001-397606,
filed on Dec. 27, 2001, and JP-2002-335008, filed on Nov. 19,
2002.
TECHNICAL FIELD
[0002] The present invention relates to a resin composition and to
a container packaging film and the like used in a container
packaging bag for housing a container filled with a food or a
medicament. More specifically, the present invention relates to a
container packaging film ensuring excellent appearance and
excellent antiblocking property between a container and a container
packaging bag after high-pressure steam sterilization, and also a
sealant film, a laminate, a container packaging bag and a container
package using the container packaging film.
BACKGROUND ART
[0003] Conventionally, packaging of housing a container filled with
a food, a medicament or the like in a container packaging bag has
been performed. The purpose of packaging varies depending on use
and the container packaging bag is being used for various purposes,
for example, for the purpose of mainly protecting the contents from
deterioration, such as prevention of scratches on the container
surface, prevention of mechanical damage of the container itself
and prevention of permeation of oxygen or ultraviolet light, and
for the purpose of describing the contents in the container, such
as clarification of contents or handling standard by printing or
the like.
[0004] The problem often encountered in packaging a container in a
container packaging bag is that the container and the container
packaging bag undergo blocking during storage of the packaged
container in a storehouse or the like and the container cannot be
easily taken out from the container packaging bag on use. From the
aspect of safety and hygiene, the case of subjecting a container
package obtained by packaging a container in a container packaging
bag to high-pressure steam sterilization before use is recently
increasing. Furthermore, for increasing productivity, the
high-pressure steam sterilization temperature is sometimes more
elevated to shorten the high-pressure steam sterilization time. The
blocking is more liable to occur as the temperature increases and
therefore, it is a great technical subject demanded for the
container package to solve this problem of blocking. In the case
where the container is a medical container, for more stably
maintaining constant the quality of the contents in the container,
the high-pressure steam sterilization is performed by
depressurizing the container package to reduce the volume between
the medical container and the container packaging bag and to
provide a state in which the container packaging bag and the
medical container are in tight contact. In the container package
used under such conditions, blocking is readily generated.
[0005] As one method for preventing the blocking, there has been
employed a method of selecting the materials for the contact
surface between the container and the container packaging bag to be
of different materials or to use a construction material having a
high melting point or glass transition temperature and having high
heat resistance. This method is effective, but on the other hand,
the construction material, constitution and the like of the
container or film are disadvantageously limited. For example,
heat-sealing is generally acknowledged as a most inexpensive method
for forming a container packaging film into a bag to obtain a
container packaging bag and the materials widely used for the
container packaging bag suitable for the heat-seal are
propylene-base or ethylene-base polymers, so-called polyolefins. If
these are limited, it raises a great problem in profitability and
this is not preferred.
[0006] As another method for preventing the blocking, there is
known a method of physically roughening the surface of the
heat-seal layer of film to reduce the contact area with the
container as in the case of wrapping a polyolefin-base container
with a film having a heat-seal layer composed of a polyolefin-base
resin. Specific examples of this method include a method of
imparting a roughness to the film by roughening treatment (e.g.
Japanese Unexamined Patent Application, First Publication No. Hei
5-309124), a method of imparting a physical deformation to the film
by crimping, embossing, or the like. Other method using a resin
composition includes a method in which a polymer composition
comprising polybutene-1 and polypropylene and/or
poly-4-metylpentene-1 is used for inner surfaces of a container
packaging bag(e.g., Japanese Unexamined Patent Application, First
Publication No. Hei 5-31156). Furthermore, a method of adding an
additive to the polyolefin constituting the heat-seal surface of
film can be used. The additive used here includes an inorganic
filler such as silica and talc, an organic antiblocking agent such
as spherical crosslinked methyl methacrylate, a metallic soap-base
lubricant such as calcium stearate, and a fatty acid amide-base
lubricant often used as a slipping agent of film, such as erucic
acid amide.
[0007] However, these methods have a problem in that the film
appearance becomes poor or the additive bleeds and adheres to the
container. Furthermore, if the temperature for high-pressure
steralization exceeds 121.degree. C., then sufficient antiblocking
cannot be achieved. In particular, depending on the construction
material of the container, the additive contained in the container
packaging bag may pass through the wall of the container by the
operation such as high-pressure steam sterilization performed in
the state of the container being in tight contact with the
container packaging bag and this causes mingling of a foreign
matter or deterioration of the contents. Therefore, a container
packaging bag using substantially no additive, having excellent
appearance and also exhibiting antiblocking property is being
demanded.
[0008] Under these circumstances, the present invention has been
made and the main object of the present invention is to provide a
resin composition comprising a polyolefin-base material and
suitable for a container packaging film having excellent appearance
and antiblocking property and free from fear of mingling of a
foreign matter into the contents of the container. Also, the object
of the present invention is to provide a container packaging film
comprising the resin composition of the present invention; a
sealant film, a laminate, a container packaging bag and a container
package using the container packaging film. The reason why these
preferred properties are imparted is not clearly known but it is
presumed that by using a resin composition comprising specific
polyolefin-base materials, the surface is uniformly roughened and
the contact area with a container is reduced, as a result, the
blocking property is decreased even if an antiblocking agent is not
substantially used.
DISCLOSURE OF THE INVENTION
[0009] As a result of extensive investigations to attain the
above-described objects, the present inventors have found that
these objects can be attained by forming a resin composition
comprising a combination of specific polyolefin-base resins into a
container packaging film and using the film for the surface to come
into contact with a container. The present invention has been
accomplished based on this finding. More specifically, the present
invention relates to a resin composition and a container packaging
film, a sealant film, a laminate, a container packaging bag and a
container package using the resin composition, shown in the
following (1) to (10).
[0010] (1) A resin composition comprising from 40 to 90 mass % of a
propylene-base polymer and from 10 to 60 mass % of a high-density
polyethylene (the total of the propylene-base polymer and the
high-density polyethylene is 100 mass %), and substantially not
containing a lubricant and not containing an antiblocking agent,
and the ratio of MFR of the propylene-base polymer at 230.degree.
C. to MFR of the high-density polyethylene at 190.degree. C. being
from 5 to 200.
[0011] (2) A container packaging film made from a composition
comprising a propylene-base polymer and a high-density
polyethylene, the coefficient of kinetic friction between the
container packaging films after high pressure steam sterilization
at 125.degree. C. for 30 min. being 0.4 or less, and substantially
not containing a lubricant and not containing an antiblocking
agent.
[0012] (3) A container packaging film made from a composition
comprising from 40 to 90 mass % of a propylene-base polymer and
from 10 to 60 mass % of a high-density polyethylene (the total of
the propylene-base polymer and the high-density polyethylene is 100
mass %), the ratio of MFR of the propylene-base polymer at
230.degree. C. to MFR of the high-density polyethylene at
190.degree. C. being from 5 to 200, and substantially not
containing a lubricant and not containing an antiblocking
agent.
[0013] (4) A sealant film comprising a support layer and a sealant
layer, wherein the sealant layer is the container packaging film
described in (2) or (3).
[0014] (5) A laminate comprising a layer composed of the container
packaging film described in (2) or (3), or the sealant film
described in (4), and at least one layer selected from the group
consisting of a gas barrier layer, a printing layer and a
protective layer.
[0015] (6) A container packaging bag, wherein the surface coming
into contact with a container is the container packaging film
described in (2) or (3).
[0016] (7) A container package, wherein a container is housed in
the container packaging bag described in (6) and subjected to
high-pressure steam sterilization.
[0017] (8) The container package as described in (7), wherein the
high-pressure steam sterilization temperature is 121.degree. C. or
more.
[0018] (9) The container package as described in (7) or (8),
wherein the container is a medical container.
[0019] (10) The container package as described in any one of (7) to
(9), wherein the outer surface of the container, coming into
contact with the container packaging bag is composed of a
propylene-base polymer.
BEST MODE FOR CARRYING OUT THE INVENTION
[0020] The present invention is described in detail below.
[0021] The propylene-base polymer for use in the present invention
is a propylene homopolymer or a propylene..alpha.-olefin copolymer
containing a propylene and an .alpha.-olefin having from 2 to 20
carbon atoms except for propylene. Examples of the .alpha.-olefin
include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methylpentene-1,
1-octene, 1-decene and 1-dodecene. These are used individually or
in combination of two or more thereof. Among these .alpha.-olefins,
preferred are ethylene, 1-butene, 1-pentene, 1-hexene,
4-methylpentene-1 and 1-octene, more preferred is ethylene. As for
the kind of the copolymer, examples thereof include a random
copolymer and a so-called block copolymer commonly called
high-impact polypropylene. Among these, a block copolymer is
preferred because when a sealant film described later is formed,
the interlayer adhesive strength with the support layer and the
flexibility are excellent. The catalyst used at the production of
the propylene-base polymer is not particularly limited, and a
metallocene-base catalyst other than a conventional Ziegler.Natta
catalyst can be used. These can be produced by various production
processes such as bulk process, solution process, slurry process
and gas-phase process.
[0022] The MFR (melt flow rate) of the propylene-base polymer
measured in accordance with JIS K 7210 under the conditions of a
temperature of 230.degree. C. and a load of 21.18N is preferably
from 0.1 to 50 g/10 min. If the MFR is less than this range, the
moldability is liable to decrease, whereas if the MFR exceeds this
range, the strength and the heat-seal property are liable to
decrease. The MFR is more preferably from 0.1 to 20 g/10 min, still
more preferably from 0.25 to 20 g/10 min.
[0023] The high-density polyethylene for use in the present
invention is an ethylene homopolymer or an ethylene..alpha.-olefin
copolymer containing an ethylene and an .alpha.-olefin having from
3 to 20 carbon atoms. Preferable examples of the .alpha.-olefin
include propylene, 1-butene, 1-pentene, 1-hexene,
4-methylpentene-1, 1-octene, 1-decene and 1-dodecene. These are
used individually or in combination of two or more thereof. Among
these, preferred are 1-butene, 1-pentene, 1-hexene,
4-methylpentene-1 and 1-octene.
[0024] The density of the high-density polyethylene used in the
present invention is usually 0.940 g/cm.sup.3 or more, preferably
0.945 g/cm.sup.3 or more, more preferably 0.950 g/cm.sup.3 or more.
The upper limit is not particularly limited but is about 0.965
g/cm.sup.3. If the density is less than 0.940 g/cm.sup.3, poor
antiblocking property is liable to result and particularly when
sterilization is performed at a temperature exceeding 121.degree.
C., the antiblocking property is liable to greatly decrease.
[0025] The MFR of the high-density polyethylene measured in
accordance with JIS K 7210 under the conditions of a temperature of
190.degree. C. and a load of 21.18N is preferably from 0.05 to 50
g/10 min. With MFR in this range, the resin composition can have a
melt tension in an appropriate range and a film can be easily
molded. The MFR is more preferably from 0.05 to 20 g/10 min, still
more preferably from 0.1 to 10 g/10 min.
[0026] As for the blending ratio of the propylene-base polymer and
the high-density polyethylene in the resin composition of the
present invention, assuming that the total of the propylene-base
polymer and the high-density polyethylene is 100 mass %, the
propylene-base polymer is from 40 to 90 mass %, preferably from 60
to 80 mass %. If the ratio of the propylene-base polymer blended is
less than 40 mass %, the appearance of the container packaging film
is worsened or the heat resistance is disadvantageously
insufficient, whereas if the ratio of the propylene-base polymer
blended exceeds 90 mass %, the antiblocking property
deteriorates.
[0027] In the resin composition of the present invention, the ratio
[MFR(PP)/MFR(HD)] of MFR of the propylene-base polymer [MFR(PP)] to
MFR of the high-density polyethylene [MFR(HD)] is from 5 to 200,
preferably from 10 to 100, more preferably from 15 to 50. If the
MFR(PP)/MFR(HD) is less than 5, the antiblocking property may not
be sufficiently high, whereas if it exceeds 200, problems
disadvantageously arise in the moldability or in the film
appearance, for example, gel, fish eye or the like is readily
generated on the container packaging film.
[0028] The container packaging film of the present invention is
made from a resin composition comprising a propylene-base polymer
and a high-density polyethylene, and not substantially containing
lubricant and not containing antiblocking agent, wherein the
coefficient of kinetic friction between the container packaging
films after high pressure steam sterilization at 125.degree. C. for
30 min. is 0.4 or less, Herein, the coefficient of kinetic friction
is a value obtained according to JIS K 7125. If the coefficient of
kinetic friction is 0.4 or less, then ease of opening of a
container packaging film ameliorates and container can be more
easily taken out of the container package. Furthermore, the
coefficient of kinetic friction tends to be decreased if the
blending ratio of the high-density polyethylene is decreased.
Moreover, the container packaging film made from the resin
composition of the present invention has excellent heat resistance
and antiblocking properties.
[0029] The method for obtaining the container packaging film of the
present invention is not particularly limited and this film can be
obtained, for example, by mixing respective components for use in
the resin composition of the present invention in a mixer such as
mixing roll, Banbury mixer, Henschel, tumbler and ribbon blender,
once forming the mixture into pellets using an extruder or the
like, and thereafter molding a film according to various film
molding methods. Examples of the film molding method include a
method of producing a film by a water cooling or air cooling
extrusion inflation method or a T-die casting method. The thickness
of the container packaging film of the present invention is from 30
to 300 .mu.m, preferably from 30 to 200 .mu.m.
[0030] The container packaging film of the present invention can be
used as a single layer sealant film but can also be used as a
sealant film where a sealant layer and a support layer are
laminated using the container packaging film as the sealant layer.
By laminating with a support layer, a sealant film having high
transparency and having high smoothness in the support layer side
can be obtained. The support layer is not particularly limited but
general polyolefins such as ethylene-base polymer and
propylene-base polymer can be used. Among these, a propylene-base
polymer is preferred because of its high heat resistance. Examples
of the propylene-base polymer include homopolypropylene,
propylene.ethylene random copolymer and propylene.ethylene block
copolymer. Among these, propylene.ethylene block copolymer is
preferred because of high impact resistance. The ratio in the
thickness between the support layer and the sealant layer is
preferably support layer/sealant layer =50 to 95/5 to 50.
[0031] The laminate of the present invention comprises a layer
composed of the container packaging film or sealant film of the
present invention, and at least one layer selected from the group
consisting of a gas barrier layer, a printing layer and a
protective layer. The material for use in the gas barrier layer,
printing layer and protective layer is not particularly limited but
specific examples thereof include polyethylene, polypropylene,
ethylne.vinyl acetate copolymer saponification product (EVOH),
aluminum foil, biaxially stretched or non-stretched polyamide,
biaxially stretched or non-stretched polyethylene terephthalate
(PET) or polyethylene naphthalate (PEN), aluminum oxide-deposited
PET and silica-deposited PET.
[0032] For obtaining the laminate of the present invention various
known molding methods can be used. Specific examples thereof
include a method of simultaneously molding a plurality of layers by
melt molding, such as water cooling or air cooling (co)extrusion
(multilayer) inflation method and (co)extrusion (multilayer) T-die
casting method, a method of molding single layer films or sheets
and laminating these films or sheets using an adhesive or the like,
such as dry lamination method, and a method of previously molding
one part film or sheet and melt-laminating the other part film or
sheet thereon, such as extrusion lamination method. Among these, a
water cooling or air cooling (co)extrusion (multilayer) inflation
method and a (co)extrusion (multilayer) T-die method are
preferred.
[0033] The container packaging bag of the present invention is
obtained by forming the container packaging film or sealant film of
the present invention into a bag using heat-seal. For the surface
to come into contact with a container, the container packaging film
composed of the resin composition of the present invention is used.
When a container is housed and packaged therein, blocking with the
container is not generated and the appearance is good. The
container packaging bag can be obtained by using the container
packaging film, sealant film or laminate of the present invention
and heat-sealing it into a bag form by means of heat,
high-frequency wave, ultrasonic wave or the like. A method of
obtaining the container after vacuum molding may also be used.
Furthermore, the resin composition of the present invention can be
also formed into a container from the beginning by a hollow molding
method or the like. Needless to say, a surface of the container
packaging film can be subjected to roughening treatment, depending
on the use.
[0034] The container package of the present invention is obtained
by housing a container in the container packaging bag of the
present invention and subjecting it to high-pressure steam
sterilization. For the high-pressure steam sterilization, a method
such as submerging system and spray system commonly used in the
retort field and medical field is used. Particularly, from the
standpoint of, for example, elevating the productivity, keeping the
taste of food or improving the sterilization property, the
high-pressure steam sterilization temperature which has been
heretofore on the order from 100 to 115.degree. C. is recently
elevated and a high-pressure steam sterilization temperature of
121.degree. C. or more is employed. The construction material of
the container is also changing from polyethylene, vinyl chloride
and the like to propylene-base polymer and the like having high
heat resistance and the high-pressure steam sterilization is
performed after packaging a container. The container includes a
single layer container composed of a single material and a
multilayer container composed of various materials. In either case,
an adhesive layer may be provided, if desired. In view of
moldability and profitability, polyolefin-base resins are used as
the container material in many cases. The container package housing
such a container exhibits superior heat resistance and very
excellent antiblocking property after the high-pressure steam
sterilization at 121.degree. C. or more, and also exhibits
excellent antiblocking property after high pressure steralization
at 125.degree. C. Particularly, in the case where the container is
composed of a polyolefin-base resin-made flexible sheet or film,
the container is tightly contacted with the container packaging bag
to readily generate blocking. However, even in such a case, the
container package of the present invention scarcely undergoes
blocking. Furthermore, in the case of a film bag, a blow bag, a
blow bottle and the like used as a medical container for high
calorie infusion, peritoneal dialysis infusion (CAPD) or the like,
the container package of the present invention free from fear of
bleeding of an antiblocking agent is advantageous.
[0035] When a propylene-base polymer is used for the surface of a
container coming into direct contact with the container packaging
bag of the present invention, namely, the outer surface of the
container, a propylene-base copolymer comprising ethylene or
butene-1 as a copolymerization component, or a propylene-base
polymer having added thereto an elastomer component such as
styrene-base elastomer and olefin-base elastomer is sometimes used
so as to impart flexibility to the container. The propylene-base
copolymer or propylene-base polymer containing an elastomer
component readily undergoes blocking as compared with a propylene
homopolymer and therefore, the effect of the container package of
the present invention having excellent antiblocking property is
more clearly exerted.
[0036] In the resin composition comprising a specific
propylene-base polymer and a specific high-density polyethylene of
the present invention, other polymers can of course be blended
within a range so as not to impair the object of the present
invention. Specific examples of such a polymer include a so-called
high-pressure low-density polyethylene, a linear low-density
polyethylene, an ethylene..alpha.-olefin elastomer, various
styrene-base elastomers such as styrene.butadiene elastomer, an
ethylene.vinyl acetate copolymer, an ethylene.(meth)acrylic acid
ester copolymer, an ethylene.(meth)acrylic acid copolymer and its
ionomer; however, the present invention is not limited thereto. The
blending ratio of the other polymers to the whole resin composition
of the present invention is less than 40 mass %, and preferably
less than 20 mass %. In particular, if an amount of the other
polymers except polyolefin, such as styrene-base elastomers is
increased, then a heat seal strength of a portion to be heat-sealed
in the container packaging tends to deteriorate.
[0037] Also, in the sealant film, laminate and container packaging
bag of the present invention, an organic or inorganic filler and
other commonly used known additives such as antistatic agent,
antioxidant, anticlouding agent, organic or inorganic pigment,
ultraviolet absorbent and dispersant may be appropriately blended,
if desired, so as to, for example, improve the strength, reduce the
volume or lower the calorie at the burning for disposal, within the
range of not seriously impairing the effect of the present
invention. However, in the resin composition and container
packaging film of the present invention, a lubricant and an
antiblocking agent are necessary to be substantially absent to such
an extent of not causing bleeding. Herein, "substantially absent"
means that a lubricant and antiblocking may be present to such an
extent that they do not bleed. More specifically, it is preferable
for an antiblocking agent to be present at 4000 ppm or less, and
for a lubricant to be 4000 ppm or less. It is more preferable for
the antiblocking agent to be 1000 ppm or less, and for the
lubricant to be 1000 ppm or less. Most preferably, they are not
contained at all.
EXAMPLES
[0038] The present invention is described in greater detail below
by referring to Examples and Comparative Examples, however, the
present invention is not limited to the Examples.
[0039] The propylene-base polymer and high-density poly-ethylene
used are described below. The MFR of propylene-base polymer was
measured in accordance with JIS K 7210 at a temperature of
230.degree. C. under a load of 21.18N. The MFR of high-density
polyethylene was measured in accordance with JIS K 7210 at a
temperature of 190.degree. C. under a load of 21.18N.
[0040] (Propylene-Base Polymer)
[0041] A1: Propylene homopolymer having an MFR of 15 g/10 min.
[0042] A2: Propylene.ethylene random copolymer having an MFR of 5
g/10 min, ethylene content: 4.3 mass %.
[0043] A3: Propylene.ethylene block copolymer having an MFR of 2.2
g/10 min.
[0044] (High-Density Polyethylene)
[0045] B1: MFR: 1 g/10 min, density: 0.960 g/cm.sup.3
[0046] B2: MFR: 0.6 g/10 min, density: 0.955 g/cm.sup.3
[0047] (Additives)
[0048] C1: Aluminosilicate (Silica-base antiblocking agent)
[0049] C2: Polymethyl methacrylate (PMMA)-base antiblocking
agent
[0050] A method for measuring physical properties is described
below.
[0051] (Coefficient of Kinetic Friction)
[0052] 1000 mL of water was put into a container packaging bag
having an inner dimension of 30.times.30 cm, with three edges were
heat-sealed, and then remaining one edge was heat-sealed to prepare
a container packaging bag containing water. The water-containing
container packaging bag was subjected to sterilization treatment at
125.degree. C. for 30 min using a spray-system high-pressure steam
sterilizer, and then the bag was opened to discard the water.
Coefficients of kinetic friction of the inner surfaces of the bag
that was air-dried was measured according to JIS K 7125, under the
conditions of 23.degree. C..times.50% RH and using a measuring
device, Friction Tester Type TR (manufactured by Toyo Precision
Machine, Ltd.).
[0053] The method of preparing samples is describe below.
[0054] (Container)
[0055] The propylene-ethylene random copolymer of A2 was molded at
a temperature of 230.degree. C. using a T-die film casting machine
to obtain a film having a thickness of 200 .mu.m. This film was cut
into 20 cm.times.20 cm square, two films were combined and three
edges of one film were heat-sealed with three edges of another
film, respectively, at temperature of 180.degree. C. and pressure
of 0.2 MPa, for 1 second with heat-sealing width being 10 mm, to
obtain a container. After filling 1 liter of distilled water in
this container, the remaining one edge and another part one edge
were heat-sealed and this was used as a container sample.
[0056] (Container Packaging Film, Container Packaging Bag,
Container Package and High-Pressure Steam Sterilization)
[0057] A propylene-base polymer, a high-density polyethylene and an
additive were mixed by a Henschel mixer to give a composition shown
in Table 1. The obtained composition was cast at a temperature of
230.degree. C. by a T-die casting machine to obtain a container
packaging film of 70 .mu.m. This film was cut into a 35 cm square,
two films were combined, and three edges of one film were
heat-sealed with three edges of another film, respectively, at
temperature of 180.degree. C. and pressure of 0.2 MPa, for 1 second
with heat-sealing width being 10 mm, to manufacture a container
packaging bag. In this bag, the container sample prepared above was
housed. Then, while depressurizing the inside by a vacuum pump, the
remaining one edge and another part one edge of films were
heat-sealed to obtain a container package.
[0058] This sample was subjected to a sterilization treatment at
125.degree. C. for 30 minutes using a spray-system high-pressure
steam sterilizer.
[0059] The evaluation methods are described blow.
[0060] (Appearance)
[0061] The container after the high-pressure steam sterilization is
taken out of the container packaging bag, and a region of 30
cm.times.30 cm of the container package was divided into 9 sections
each in a size of 10 cm.times.10 cm and the roughened state of the
inner and outer surfaces was observed with an eye. The number of
sections in a uniform ground glass state and having a good
appearance and the number of sections having a non-uniformly
roughened surface and a poor appearance were counted and the
evaluation was performed according to the following criteria:
[0062] .smallcircle.: The number of sections having a good
appearance is from 7 to 9.
[0063] .DELTA.: The number of sections having a good appearance is
from 4 to 6.
[0064] X: The number of sections having a good appearance is from 0
to 3.
[0065] (Antiblocking Property)
[0066] The container package after the high-pressure steam
sterilization was opened and the container was taken out with a
hand from the container package. The evaluation was performed
according to the following criteria:
[0067] .smallcircle.: The container can be easily taken out without
causing any catch or resistance.
[0068] .DELTA.: Blocking is weakly generated between a part of the
container and a part of the container packaging bag but the
container can be easily taken out.
[0069] X: Strong blocking is generated between a part of the
container and the container packaging bag and the container is
taken out with difficulty.
[0070] (Film Impact)
[0071] Using the films that were obtained by division of the
container packaging bag prepared by high pressure steam
sterilization as for the measurement of coefficient of kinetic
friction, the film impact was measure according to JIS P8184 under
the conditions of 23.degree. C. and 50% RH.
Examples 1 to 5 and Comparative Examples 1 to 5
[0072] Using a resin composition of the kind and blending amount
shown in Table 1, a container packaging film, a container packaging
bag and a container package were manufactured. The appearance and
antiblocking property were evaluated and the results obtained are
shown in Table 1.
Examples 6 and 7
[0073] Two-layers sealant film having, as a sealant layer, a resin
composition with the same kind and blending amount as in Example 1,
and, as support layer, propylene-base polymer as shown in Table 2
was subjected to cast using a multi-layer T-die casting machine at
230.degree. C. Evaluation of the film impact is shown in Table
2.
1 TABLE 1 Propylene- Additive MFR Coefficeint Base High-Density
(parts (PP)/ of Kinetic Appear- Anti- Polymer Polyethylene by MFR
Friction ance blocking (mass %).sup.1) (mass %).sup.1) mass).sup.2)
(HD) (N/N) of Film Property Ex. 1 A1 (70) B1 (30) 0 15 0.28
.largecircle. .largecircle. Ex. 2 A1 (50) B1 (50) 0 15 0.29 .DELTA.
.largecircle. Ex. 3 A2 (80) B2 (20) 0 8 0.30 .largecircle. .DELTA.
Ex. 4 A1 (70) B2 (30) 0 25 0.29 .largecircle. .largecircle. Ex. 5
A1 (30) B1 (70) 0 15 0.36 X .largecircle. Comp. A1 (100) 0 C1 --
0.45 X .DELTA. Ex. 1 (0.5) Comp. A2 (100) 0 C2 -- 0.48 X X Ex. 2
(0.5) Comp. 0 B1 (100) 0 -- 0.45 .largecircle. X Ex. 3 Comp. A1
(95) B1 (5) 0 15 0.55 .largecircle. X Ex. 4 .sup.1)Blending ratio
assuming that the total of propylene-base polymer + high-density
polyethylene is 100 mass %. .sup.2)Parts by mass per 100 parts by
mass in total of propylene-base polymer + high-density
polyethylene
[0074]
2 TABLE 2 Thickness (Support Support Layer/Sealant Film Impact
(unit Layer (mass %) Layer) (.mu.m/.mu.m) kg*cm/mm) Ex. 6 A1 (100)
40/10 120 Ex. 7 A3 (100) 40/10 260
Industrial Applicability
[0075] As described in detail in the foregoing pages, the container
packaging film comprising the resin composition of the present
invention uses an inexpensive polyolefin and therefore, costs low.
The film has excellent appearance and antiblocking property and
therefore, when formed into a container packaging bag, the
container can be easily taken out. Furthermore, the film does not
substantially contain a lubricant and not contain an antiblocking
agent and free of fear of contamination of the container and
therefore, can be used in the field of container packaging such as
medical container packaging. Thus, the present invention is
useful.
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