Note: Descriptions are shown in the official language in which they were submitted.
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1
LAMINATED FILM OR SHEET AND
BOX-SHAPED VESSEL PREPARED THEREFROM
This is a divisional application of Canadian Patent
Application Serial No. 2,014,460, filed on April 12, 1990.
Field of the Invention
The present invention relates to a film or sheet
composed of a laminate comprising a layer of a specific resin
and a paper layer, and a box-shaped vessel (hereinafter
referred to as "carton") prepared from this film or sheet.
The subject matter of the present divisional
application relates to a film or sheet, which is composed of a
laminate comprising a layer of poly-4-methyl-1-pentene having a
melting point within a specific range and a paper layer, and to
a carton prepared from this film or sheet. The subject matter
of the parent application was restricted to a laminate
comprising a layer of ordinary poly-4-methyl-1-pentene, an
intermediate layer of a specific resin and a paper layer, and
also to a carton prepared from this film or sheet. However, it
should be understood that the expression "the invention" and
the like, encompass he subject matter of both the parent
application and this divisional application
Background of the Invention
Recently, the cooking method using an electronic oven
has made a rapid progress, and a variety of foods such as
dishes and cakes can be easily prepared by using an electronic
oven.
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la
When a food is cooked by an electronic oven, the food
to be cooked is contained in a tray-shaped vessel formed of a
laminate comprising, for example, an inner layer of a 4-methyl-
1-pentene polymer and an outer paper layer, and the food is
subjected to high-frequency heating.
Foods to be cooked include foods containing oil and
fat components such as butter and margarine, for example, pound
cakes, and foods on which a sauce containing oil and fat
components is poured to complete cooking after heating, and it
sometimes happens that
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after heating in an electronic oven or after pouring of
a sauce containing oil and fat components after side
heating, foods are preserved in a box-shaped vessel.
Since the heretofore used covering layer of a 4-
methyl-1-pentene polymer has a high rigidity, fine
cracks are sometimes formed in the covering layer.
Moreover, when oil and fat components as described above
are present, they permeate into the paper layer
constituting the vessel with the lapse of time, the
paper layer as a whole becomes oily to degrade the
appearance of the vessel, and there is a risk of
contamination of the hand or clothing with oil and fat
components at the time of handling.
Summary of the Invention
It is a primary object of the present invention to
provide a laminated film or sheet in which formation of
cracks in the covering layer is prevented so that
permeation of oil and fat components from a contained
cooked food is prevented, and a carton prepared from
this film or sheet.
Another object of the present invention is to
provide a laminated film or sheet in which by forming an
intermediate layer of a specific resin in addition to a
covering layer of a 4-methyl-1-pentene polymer,
permeation of oil and fat components from a contained
cooked food can be prevented, and a carton prepared from
this laminated film or sheet.
In accordance with one fundamental aspect of the
present invention, the foregoing objects can be attained
by providing a laminated film or sheet having at least
two layers, which comprises (A) a layer of poly-4-
methyl-1-pentene having a melting point of 190 to 230 °C
and (B) a paper layer.
In accordance with another aspect of the present
invention, there is provided a laminated film or sheet
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having at least three layers, which comprises (A) a
layer of poly-4-methyl-1-pentene, (B) an intermediate
layer of a propylene polymer and (C) a paper layer.
In this laminated film or sheet, the melting point
of the poly-4-methyl-1-pentene constituting the inner
layer is generally 190 to 245 °C and preferably 200 to
235 °C. The propylene polymer constituting the
intermediate layer is a propylene homopolymer or.
propylene/ethylene random copolymer having MFR (melt
flow rate) of 1 to 200 g/10 min, preferably 10 to
100 g/100 min.
In accordance with still another aspect of the
present invention, there is provided a laminated film or
sheet having at least three layers, which comprises (A)
a layer of poly-4-methyl-1-pentene, (B) an intermediate
layer of a polyester type polymer and (C) a paper layer.
In this laminated film or sheet comprising the
above-mentioned intermediate layer, the permeation of
oil and fat components into the paper layer is further
prevented, and a carton having an excellent oil
resistance can be prepared from this laminated film or
sheet.
In accordance with still another aspect of the
present invention, there is provided a laminated film or
sheet having at least three layers, which comprises (A).
a layer of poly-4-methyl-1-pentene having a high melting
point, (B) an intermediate layer of poly-4-methyl-1-
pentene having a low melting point and (C) a paper
layer.
The melting point of the high-melting-point poly-4-
methyl-1-pentene constituting one layer of this
laminated film or sheet is 220 to 245 °C, and the
melting point of the low-melting-point poly-4-methyl-1-
pentene constituting the intermediate layer is 190 to
230 °C.
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If the covering layer is divided into two layers
composed of poly-4-methyl-1-pentenes differing in the
characteristics and the intermediate layer is formed of
poly-4-methyl-1-pentene having a low melting point, the
resistance to permeation of oil and fat components is
highly improved.
Detailed Description of the Preferred Embodiments
In the laminated film or sheet of the present
invention, the covering layer is formed of poly-4-
methyl-1-pentene.
The poly-4-methyl-1-pentene used in the present
invention is a homopolymer of 4-methyl-1-pentene or a
copolymer of 4-methyl-1-pentene with up to 20 mole%,
preferably up to 12 mole% of an d -olefin having 2 to 20
carbon atoms, such as ethylene, propylene, 1-butene, 1-
hexene, 1-octene, 1-decene, 2-tetradecene or 1-
octadecene. Crystalline poly-4-methyl-1-pentene having
a melting point of 190 to 230°C is preferably used.
This polymer can be prepared according to a known
process, for example, the process disclosed in Japanese
Unexamined Patent Publication No. 59-206418. MFR of the
poly-4-methyl-1-pentene is preferably 5 to 1000 g/10
min, and poly-4-methyl-1-pentene having MFR of 70 to
300 g/10 min is especially preferably used because
moldability and heat resistance are very good.
In general, increase of the amount of the d -olefin
to be copolymerized results in lowering of the melting
point, but the melting point is influenced by the kind
of the o~-olefin, the catalyst used and other
polymerization conditions. However, since the relations
of these factors to the melting point can be
experimentally determined in advance, persons skilled in
the.art will easily obtain poly-4-methyl-1-pentene
having a desired melting point.
If a layer of poly-4-methyl-1-pentene having a
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relatively low melting point of 190 to 230 °C is
laminated with a paper layer, even under heating in an
electronic oven, the above-mentioned oil and fat
components are not allowed to permeate into the paper
layer, and therefore, a laminated film or sheet suitable
as a vessel material can be provided.
Papers customarily used as the material for boxes
or cases, such as clay-coated paper and milk carton
paper, can be used as the paper constituting the paper
layer. However, use clay-coated paper is recommended
because the permeation rate of oil and fat components can
be maintained at a very low level even if pinholes or
small cracks are formed in the poly-4-methyl-1-pentene
layer by unexpected shock or rubbing or even if the oil
and fat components happen to permeate from the end face
of the laminated film or sheet. Moreover, since this
clay-coated paper is excellent in the printability, the
laminated sheet or film is suitably used as a base
material to be printed when a print layer is formed on
the surface of the vessel according to need.
The laminated film or sheet of the present
invention can be prepared by extrusion-coating poly-4-
methyl-1-pentene directly on the surface of paper, or by
extrusion-coating poly-4-methyl-mentene on the surface
of paper which has been subjected to an adhesiveness-
increasing treatment according to a known method, for
example, by coating the paper surface with an anchor
coat agent of an organic titanium, polyethyleneimine or
isocyanate type or bonding an adhesive polyolefin or
high-pressure polyethylene as the undercoat to the paper
surface. In the latter case, a laminated film or sheet
having a three-layer structure is obtained.
Formation of Laminated Film or Sheet
The poly-4-methyl-1-pentene constituting the inner
layer of the laminate of the present invention is
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excellent in the adaptability to extrusion coating at a
high speed, and therefore, the poly-4-methyl-1-pentene
can be extrusion-coated at a high speed by using an
ordinary extrusion-coating apparatus. By this extrusion
coating a laminated film or sheet having excellent
mechanical properties and interlaminar adhesiveness can
be obtained. If a gas such as air or nitrogen gas is
blown to both the ends of the extruded film or sheet at
the extrusion coating, neck-in or edge wave at both the
ends of the extruded film or sheet can be prevented, and
in this case, if blowing of the gas is effected in the
vicinity of the point of the contact of the extruded
film or sheet with the paper substrate from the side
where the extruded film or sheet is not contacted with
the paper substrate, the extrusion coating is
accomplished at a high speed more stably.
As the method for blowing a gas to the extruded
film or sheet, there can be mentioned a method in which
a metal tube such as an aluminum tube or copper tube or
a conduit tube such as a thermoplastic resin tube is
arranged downstream of a die, and a gas is blown to the
extruded film or sheet of poly-4-methyl-1-pentene at an
optional point in the course of up to the point of the
contact of the film or sheet extruded from the die with
the paper substrate, preferably in the vicinity of the
contact point where the extruded film or sheet is coated
on the paper substrate. The pressure of the gas to be
blown is appropriately determined in view of the
thickness of the extruded film or sheet to be coated.
However, the pressure of the gas is generally 0.5 to
5 kg/cm2G. The aperture of the top end of a nozzle for
blowing the gas is generally 1 to 50 mm2 and preferably
5 to 10 mm2. The distance between the top end of the
nozzle and the extruded film or sheet is generally 2 to
100 mm and preferably 5 to 20 mm. If the top end of the
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blowing nozzle is directed to the outer side of the.
extruded film or sheet from the inner side thereof, the
film or sheet is expanded by the blown gas and the
effect of further narrowing neck-in is preferably
attained.
When the poly-4-methyl-1-pentene constituting the
inner layer is extrusion-coated, the extrusion
temperature is ordinarily 250 to 370 °C and preferably
290 to 340 °C. The extrusion-coating speed (the take-up
speed of the covering material) is generally at least
100 m/min and preferably 150 to 500 m/min. The
thickness of the poly-4-methyl-1-pentene layer and paper
are not particularly critical, but the thickness of the
poly-4-methyl-1-pentene and paper layers are generally 1
to 2000 um and 5 to 5000 Vim, respectively, and
preferably 5 to 50 hum and 100 to 600 Vim, respectively.
Known additives such as a weathering stabilizer, a
heat stabilizer, an antistatic agent, an antifogging
agent, an antiblocking agent, a slip agent and a
colorant can be incorporated into the poly-4-methyl-1-
pentene used in the present invention, so far as the
intended objects of the present invention can be attained.
_Film or Sheet Comprising Intermediate Layer
In the case where a resin layer of a propylene
polymer or polyester type polymer is formed as the
intermediate layer, poly-4-methyl-1-pentene having an
ordinary melting point, for example, a melting point of
190 to 245 °C is used. The kinds of the poly-4-methyl-
1-pentene and comonomer are the same as described above.
The same paper layer as described above is used.
(1) Intermediate Layer of Propylene Polymer
The propylene polymer constituting the intermediate
layer in the present invention includes a crystalline
homopolymer having MFR of 1 to 200 g/10 rnin, preferably
10 to 100 g/10 min, and a crystalline copolymer of
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propylene with up to 15 mole% of other olefin such as
ethylene, 1-butene, 1-hexene, 4 -methyl-1-pentene or 1-
octene.
Since the poly-4-methyl-1-pentene and propylene
polymer constituting the outer layer (covering layer)
and intermediate layer in the present invention have an
excellent adaptability to the extrusion coating at a
high speed, the extrusion coating can be performed at a
high speed, as described hereinbefore.
Furthermore, as described hereinbefore, neck-in or
edge wave on both the ends of the extruded film or sheet
can be prevented by blowing a gas such as air or nitrogen
gas to both the ends of the extruded film or sheet.
The above-mentioned method can be similarly adopted
for blowing the gas to the extruded film or sheet, and
the extrusion temperature for extrusion-coating the
poly-4-methyl-1-pentene and propylene polymer is the
same as the above-mentioned extrusion temperature
adopted for the two-layer film or sheet.
In the laminated film or sheet of the present
embodiment, the thicknesses of the poly-4-methyl-1-
pentene layer, propylene polymer layer and paper layer
can be optionally selected, but the thicknesses of the
poly-4-methyl-1-pentene layer, propylene polymer layer.
and paper layer are generally 1 to 2000,~m, 1 to 2000 ~m
and 5 to 5000 Vim, respectively, and preferably 5 to 50
um, 5 to 50 ~m and 100 to 600 Vim, respectively.
Known additives such as a weathering stabilizer, a
heat stabilizer, an antistatic agent, an antifogging
agent, an antiblocking agent, a slip agent and a
colorant can be incorporated in each of the poly-4-
methyl-1-pentene and propylene polymer used in the
present invention, so far as the attainment of the
intended objects of the present invention is not
inhibited.
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According to this embodiment of the present
invention, by adopting a laminate structure of poly-4-
methyl-1-pentene layer/propylene polymer layer/paper
layer for the laminated film or sheet, even if oil and
fat components fall in contact with the poly-4-methyl
-1-pentene layer, the permeation of these components can
be completely prevented. A carton prepared from this
laminated film or sheet shows an excellent oil
resistance, and therefore, this carton can be
advantageously used as a tray to be used for cooking in
an electronic oven, a carton for a food containing oil
and fat components, such as a cake or a bun, and other
packaging vessels.
(2) Intermediate Layer of Polyester Type Polymer
The polyester type polymer constituting the
intermediate layer in the present invention is a
thermoplastic polyester resin comprising main recurring
units of ethylene terephthalate or butylene
terephthalate and having an intrinsic viscosity ~~~ of
0.4 to 1.5 d~/g, preferably 0.5 to 1.2 d~/g, and a
melting point of 210 to 265 °C, preferably 220 to 260
°C, which is derived from terephthalic acid as the main
acid component and a diol such as ethylene glycol or
1,4-butane-diol as the main polyhydric alcohol
component. Polyethylene terephthalate is preferably
used since this polyester has an excellent extrusion
lamination processability.w
The laminated film or sheet of the present
embodiment can be prepared by extrusion-coating poly-4-
methyl-1- ._pentene and an intermediate layer-forming
polyester directly on paper by co-extrusion.
Alternatively, there can be adopted a method in which in
order to further increase the adhesion strength between
the paper and intermediate layer, according to a known
method, the paper surface is coated with an anchor coat
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agent of an organic titanium, polyethyleneimine or
isocyanate type or an adhesive polyethylene or high-
pressure polyethylene is coated as the undercoat on the
paper surface, and the poly-4-methyl-1-pentene and
polyester type polymer are extrusion-coated on the
treated paper surface. In the latter case, a laminated
film or sheet having a four-layer structure is obtained.
In the present embodiment, the poly-4-methyl-1-
pentene and polyester type polymer are extrusion-coated
by the same extrusion-coating method as adopted in the
above embodiment using the propylene type polymer for
the intermediate layer, and the gas-blowing conditions
and extrusion temperature are substantially the same as
adopted in the above-mentioned embodiment using the
propylene polymer.
In the laminated film or sheet of the present
embodiment, the thickness of the poly-4-methyl-1-pentene
layer, polyester polymer layer and paper layer can be
optionally selected, but the thickness of the poly-4-
methyl-1-pentene layer, polyester polymer layer and
paper layer are generally 1 to 2000 Vim, 1 to 2000 ~m and
5 to 5000,y~m, respectively, and preferably 5 to 50 Vim, 5
to 50 ~m and 100 to 600 Vim, respectively.
Known additives such as a weathering stabilizer, a
heat stabilizer, an antistatic agent, an antifogging
agent, an antiblocking agent, a slip agent and a
colorant can be incorporated in each of the poly-4-
methyl-1-pentene and polyester polymer used in the
present invention, so far as the attainment of the
intended objects of the present invention is not
inhibited.
According to this embodiment of the present
invention, by ad~optitxJ a laminate structure of poly-4-
methyl-1-pentene layer/polyester polymer layer/paper
layer for the laminated film or sheet, even if oil and
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fat components fall in contact with the poly-4-methyl-1-
pentene layer, the permeation of these components can be
completely prevented. A carton prepared from this
laminated film or sheet shows an excellent oil
resistance, and therefore, this carton can be
advantageously used as a tray to be used for cooking in
an electronic oven, a carton for a food containing oil
and fat components, such as a cake or a bun, and. other
packaging vessels.
(3) Laminate Comprising Two Poly-4-methyl-1-pentene
Layers
In this embodiment, a crystalline homopolymer of 4-
methyl-1-pentene or a crystalline copolymer of 4-methyl-
1-pentene with up to 20 mole%, preferably up to 12
mole%, of other o(-olefin such as ethylene, propylene,
1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene or
1-octadecene, which has a melting point of 220 to 245
°C, especially 225 to 240 °C, is preferably used as the
high-melting-point poly-4-methyl-1-pentene. This
polymer can be prepared according to a known process, for
example, the process disclosed in Japanese Unexamined
Patent Publication No. 59-206418. MFR of the hiQh-
melting-point poly-4-methyl-1-pentene is preferably 5 to
1000 g/10 min, and poly-4-methyl-1-pentene having MFR of
70 to 300 g/10 min is especially preferably used since
the moldability and heat resistance are very good.
MFR of the low-melting-point poly-4-methyl-1-
pentene is within the same range as that of the above-
mentioned high-melting-point of poly-4-methyl-1-pentene,
but the melting point is 190 to 230 °C, preferably 200
to 230 °C. Also this polymer can be prepared according
to the process disclosed in Japanese Unexamined Patent
Publication No. 59-206418. A polymer having a melting
point within the above-mentioned range can be obtained
by increasing the amount copolymerized of thee(-olefin
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over the amount of the comonomer used for the production
of the high-melting-point poly-4-methyl-1-pentene.
In general, increase of the amount of theo~-olefin
to be copolymerized results in lowering of the melting
point, but the melting point is influenced by the kind
of the d-olefin, the catalyst used other polymerization
conditions. However, since the relations of these
factors to the melting point can be experimentally
determined in advance, persons skilled in the art will
easily obtain poly-4-methyl-1-pentene having a desired
melting point.
As is apparent from the foregoing description,
there is a substantial difference of the melting point
between the high-melting-point and low-melting-point
poly-4-methyl-1-pentenes used in this embodiment of the
present invention. The melting point ranges of both the
polymers partially overlap each other, but it is
indispensable that the high-melting-point poly-4-methyl-
1-pentene should have a melting point higher than the
melting point of the low-melting-point poly-4-methyl-1-
pentene constituting the intermediate layer.
In the present embodiment, by forming one layer of
high-melting-point poly-4-methyl-1-pentene having a
higher rigidity and an intermediate layer of poly-4-
methyl-1-pentene having a lower melting point and a
lower rigidity, even if the laminated film or sheet is
heated in an electronic oven, oil and fat components as
mentioned above are not allowed to permeate into another
layer, that is, the paper layer, through these two
layers, and therefore, the laminated film or sheet is
very suitable as a material for a vessel.
The extrusion temperature adopted for extrusion-
coating two poly-4-methyl-I-pentenes constituting the
inner and intermediate layers on the paper substrate is
generally 250 to 370 °C and preferably 290 to 340 °C.
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The extrusion-coating speed (the take-up speed of the
covering material) is generally at least 100 m/min and
preferably 150 to 500 m/min.
In the laminated film or sheet of the present
embodiment, the thickness of the high-melting-point
poly-4-methyl-1-pentane layer, low-melting-point poly-4-
methyl-1-pentane layer and paper layer can be optionally
selected, but the thickness of the high-melting-point
poly-4-methyl-1-pentane layer, low-melting-point poly-4-
methyl-1-pentane layer and paper layer are generally 1
to 2000 Vim, 1 to 2000 yim and 5 to 5000 Vim, respectively,
and preferably 5 to 50 yam, 5 to 50 yim and 100 to 600 yam,
respectively.
Known additives such as a weathering stabilizer, a
heat stabilizer, an antistatic agent, an antifogging
agent, an antiblocking agent, a slip agent and a
colorant can be incorporated in each of the two poly-4-
methyl-1-pentanes used in the present invention, so far
as the attainment of the intended objects of the present
invention is not inhibited.
According to this embodiment of the present
invention, by adopting a laminate structure of high-
melting-point poly-4-methyl-1-pentane layer/low-melting-
point poly-4-methyl-1-pentane layer/paper layer for the
laminated film or sheet, even if oil and fat components
fall in content with the high-melting-point poly-4-
methyl-1-pentane layer, the carton prepared from this
laminate film or sheet shows an excellent oil
resistance, and therefore, this carbon can be
advantageously used as a tray to be used for cooking in
an electronic oven, a carton for a food containing oil
and fat components, such as a cake or a bun, and other
packaging vessels.
Since the laminated film or sheet of the present
invention has excellent oil resistance and heat
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resistance, the laminated film or sheet can be
advantageously used as release paper for the production
of an artificial leather. More specifically, the
laminated film or sheet is passed through between a nip
roll and an embossing roll to form a convexity-concavity
embossed pattern or grain pattern on the surface of the
poly-4-methyl-1-pentene layer, and the patterned surface
of the poly-4-methyl-1-pentene layer is coated with a
PVC sol or polyurethane solution as the starting
material of an artificial leather. The obtained three-
layer laminate is heated in an oven to cure the PVC or
polyurethane layer. Then, the release paper comprising
the poly-4-methyl-1-pentene and paper is peeled from the
obtained three-layer cured body, whereby an artificial
leather member composed of PVC or polyurethane, which
has the embossed pattern or grain pattern transferred on
the surface thereof, can be obtained.
Since this release paper for an artificial leather
is heated for curing the PVC or polyurethane layer
coated on the surface thereof, the release paper should
have an excellent heat resistance. Since the poly-4-
methyl-1-pentene constituting the outer layer of the
laminated film or sheet of the present invention has a
high melting point, a high heat resistance can be
manifested.
When the PVC or polyurethane layer having the
embossed or grain pattern 'transferred thereon is
separated by peeling, there is a risk of the pattern-
forming outer layer of the poly-4-methyl-1-pentene
together with the PVC or polyurethane layer. However,
in the present invention, since the outer layer and
paper layer are tightly bonded to each other through the
intermediate layer of the low-melting-point poly-4-
methyl-1-pentene, peeling of the outer layer together
with the PVC or polyurethane layer can be prevented.
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Accordingly, the laminated film or sheet of the present
invention can be used as an excellent release paper for
an artificial leather.
The present invention will now be described in
detail with reference to the following examples that by
no means limit the scope of the invention.
In the examples, the melting point, MFR and initial
modulus of elasticity were measured according to. the
following methods.
Melting Point
8y using a differential scanning calorimeter (model
DSC-II supplied by Perkin-Elmar), a sample was melting
at 260 °C for 5 minutes, cooled to room temperature at a
rate of 20 °C/min to effect crystallization and
maintained at room temperature, an endothermic curve was
determined at a temperature-elevating rate of 10 °C/min,
and the peak temperature was designated as the melting
point. The poly-4-methyl-1-pentene used in the present
invention shows one endothermic peak or a plurality of
endothermic peaks. When a plurality of leaks were
observed, the highest peaks. When a plurality of peaks
were observed, the highest peak temperature was
designated as the melting point.
MFR
The MFR value was measured under a load of 5 kg at
260 °C according to ASTM D-1238.
Initial Modulus of Elasticity
The initial modulus of elasticity was measured
according to ASTM S-790 (the test speed was adjusted to
5 mm/min).
MFR of Polypropylene
MFR of polypropylene was measured under a load of
2.16 kg at 230 °C according to ASTM D-1238.
Intrinsic Viscosity t~j of polyethylene Terephthalate
Resin
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The intrinsic viscosity of a polyethylene
terephthalate resin was measured at a temperature of
23°C in a phenol/tetrachloroethane mixed solvent (weight
ratio = 1/1).
Example 1
A crystalline copolymer of 4-methyl-1-pentene with
1-octadecene (1-octadecene content of 6% by weight)
(hereinafter referred to as "PMP (1)"~ having a melting
point of 226°C, MFR of 26 g/10 min and an initial
flexural modulus of elasticity of 5000 kg/cm2 was melted
in an extruder having a screw diameter of 65 mm and
laminated on a milk carton paper having a base weight of
290 g/m2. xhe coating thickness of PMP (1) was 20 Vim.
A case having a size of 10 cm x 10 cm x 5 cm (depth) was
prepared from the laminated paper so that the coating
layer was located on the inner surface.
Then, weighed 40 g of commercially available
margarine.(supplied by Yukijirushi Nyugyo) was placed in
the case and heated for 30 seconds by an electronic oven
(Type NE-A740 supplied by Matsushita Denki Sangyo).
After the heating, the case was allowed to stand still
at room temperature, and the number of days required for
the margarine to exude to the outer surface of the paper
layer was determined by the visual inspection. .
A case prepared in the same manner as described
above was charged with a starting powder of a chocolate
*.
cake (House Range Gourmet supplied by House Shokuhin)
and water, and cooking was carried out for 3 minutes and
seconds by using the same electronic oven as
30 described above. After the cooking, exudation~of the
content to the outer surface was examined without taking
out the content from the case.
Similarly, a case prepared in the same manner as
described above was charged with a starting powder of
butter cake (House Range Gourmef~supplied by House
*Trade-mark
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Shokuhin) and water, and cooking was carried out at a
set temperature of 190°C for 20 minutes in an oven.
After the cooking, exudation of the content to the outer
surface was examined without taking out the content from
the case.
The obtained results are shown in Table 1.
Example 2
The procedures of Example 1 were repeated i.n the
same manner except that a crystalline copolymer of 4
methyl-1-pentene with decene (decene content = 8% by
weight) ~ hereinafter referred to as "PMP (II)"~ having a
melting point of 221°C, MFR of 26 g/l0 min and an
initial flexural modulus of elasticity of 400 kg/cm2 was
used instead of PMP (I) used in Example 1.
The obtained results are shown in Table 1.
Comparative Example 1
The procedures of Example 1 were repeated in the
same manner except that a homopolymer of 4-methyl-1-
pentene (,hereinafter referred to as "PMP (H)"~ having a
melting point of 242°C, MFR of 26 g/10 min and an
initial flexural modulus of elasticity of 19000 kg/cm2
was used instead of PMP (I) used in Example 1.
The obtained results are shown in Table 1.
Comparative Example 2 .
The procedures of Example 1 were repeated in the
same manner except that a crystalline copolymer of 4-
methyl-1-pentene with 1-d~cene (1-decene content of 2.5%
by weight) ( hereinafter referred to as "PMP (III) having a
melting point of 237°C, MFR of 180 g/10 min and an
initial flexural modulus of elasticity of 13000 kg/cm2
was used instead of PMP (I) used in Example 1.
The obtained results are shown in Table 1.
CA 02311753 2000-07-13
18
y
ri N H
.4~ H
H E
Ga H C ~ M M
~ ~ N
E ~.
0
o x
UW
O
>
L1,
N
E p, N
O x
UW
C G C
ri .-i rl e-~ rl .~
.
N ~
y H E c0 ~ cri c0 ~
~
x
p, O E O
E
~ N
.. ~W W WW
x 0
W
~r
O
O
3
~ 3
"C
O ~
b
~ O O
H ~
,~ i~ G1 N ~ J-~
O N
(y, id U GLri .~
N a~
~ 'C
p.. N O 1~ O
C~
'O
x O +~
O C
a~ c ~n
w co
c
.r.,
a~
c
a~
m .., o
eo eo c
cu
M ri O 00 O C7 O
.Y, ~
~ w c~ w o w +~
U c U
v c ~
0 0 m E ~ m
~ > '
U U O M ~
~ ~
~ w w w
'C O 'O O 'd O ~
U +-~
ri U C
w C w c w c a~
c a~
O O O ~
'i C, M O O
j.1 C~ J~ ~: +d ~r ~d
J-1 v v
V 1 ' ~ b
T3 U C7 d7 G
~ N
E c c c a~ E c
~-.~ .x .x
x a~ ~ x > c x
~ at
~n z a~ z a~ o z a~
-- U U
CA 02311753 2000-07-13
67616-176
- 19 -
Example 3
PMP (III) in Comparative Example 2 and a propylene
homopolymer ~ hereinafter referred to as "PP (1)"~ having
MFR of 30 g/10 min were independently melted in
extruders having a screw diameter of 65 mm, and the melts
were laminated on a milk carton paper having a base
weight of 290 g/mm2 by using a coextrusion two-layer
die. The total coating thickness was 30 yam and each of
the coating layers had a thickness of 15 yam. A case
having a size of 10 cm x 10 cm x 5 cm (depth) was
prepared from the obtained laminated paper so that the
coating layer was located on the inner surface.
Then, weighed 40 g of commercially available
margarine (supplied by Yukijirushi Nyugyo) was placed in
I5 the case and heated for 30 seconds by an electronic oven
(Type NE-A740 supplied by Matsushita Denki Sangyo).
After the heating, the case was allowed to stand still
at room temperature, and the number of days required for
the margarine to exude to the outer surface of the paper
layer was determined by the visual inspection.
A case prepared in the same manner as described
above was charged with a starting powder of a chocolate
cake (House Range Gourmet supplied by House Shokuhin)
and water, and cooking was carried out for 3 minutes and
30 seconds by using the same electronic oven as
described above. After the cooking, exudation of the
content to the outer surface was examined without taking
out the content from the case.
Similarly, a case prepared in the same manner as
described above was charged with a starting powder of
butter cake (House Range Gourmet supplied by House
Shokuhin) and water, and cooking was carried out at a
set temperature of 190°C for 20 minutes in an oven.
After the cooking, exudation of the content to the outer
surface was examined without taking out the content from
*Trade-mark -
CA 02311753 2000-07-13
- 20 -
the case.
The obtained results are shown in Table 2.
Example 4
The procedures of Example 3 were repeated in the
same manner except that the coating thickness of PMP
(III) used in Example 2 was changed to 10 yim and the
coating thickness of PP (I) was changed to 20 um. The
obtained results are shown in Table 2.
Example 5
The procedures of Example 3 were repeated in the
same manner except that ethylene/propylene random
copolymer having ethylene content of 5% by weight
thereinafter referred to as "PP (II)"~ was used instead
of PP (I) used in Example 3. The obtained results are
shown in Table 2.
Comparative Example 3
The procedures of Example 3 were repeated in the
same manner except that a resin mixture comprising PMP
(III) and PP (I) at a ratio of 3/1 was used instead of PP
(I) used in Example 3. The obtained results are shown
in Table 2.
Comparative Example 4
The procedures of Example 3 were repeated in the
same manner except that a resin mixture comprising PMP ,
(III) and PP (I) at a ratio of 1/1 was used instead of PP
(I) used in Example 3, whereby a product having a total
coating thickness of 30,yim was obtained.
The exudation test was carried out in the same
manner as described in Example 3. The obtained results
are shown in Table 2.
Comparative Example 5
By using a single-layer die instead of the coextru-
sion two-layer die used in Example 3, PMP (III) was
laminated in a coating thickness of 15 Vim. Then, PMP
(III) was laminated again in a thickness of 15 yam while
CA 02311753 2000-07-13
- 21 -
opening a roll of the semi-finished product once wound
to obtain a product having a total coating thickness of
30 ylm. Also this product was subjected to the exudation
test in the same manner as described in Example 3. The
obtained results are shown in Table 2.
15
25
35
CA 02311753 2000-07-13 '
- 22 -
c
0
~ c~
cb H ~
G7
tr H ~ U
ri ~ ~ '~ M Lf~
H ~ x ~ a ~ ~
e- e
n, a: '''~
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0 0
~
d
H
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Q
GO H ~
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U
H H H ~ tr lf~ l.f~ O N M tf1
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W
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y
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;,c~ c~ m s~ a s~ c. ~c c~ c~o. ca
s~ a~ cu cu
c.y a~ a~ raa~ a~ a~a~ o v c o ~ o U a~
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a~c ~ ~ ~ ~ ~ ~ as
'
+~c c ~ o c c c cc~ c. x c, -~a ~ o
c~ x ~e
o x ~ .~ r,o a~ a~ d o a~ a~ z
co a~ a~
o ~ ~ ~
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.
a
H
z 4.. z v z p
E 4 c.,
CA 02311753 2000-07-13
67616-176
- 23 -
Example 6
PMP (III) snd polyethylene terephthalate
[hereinafter referred to as "PET (I)"]having an intrinsic
viscosity [rt] of 0.6 were independently melted in
extruders having a screw diameter of 65 mm and the melts
were laminated on milk carton paper having a base weight
of 290 g/mm2 by using a coextrusion two-layer die. The
total coating thickness was 30 Vim, and each of the
laminated layers had a thickness of 15 Vim. A case
having a size of 10 cm x 10 cm x 5 cm (depth) was
prepared from the obtained laminated paper so that the
coating layer was located on the inner surface.
Then, weighed 40 g of commercially available
margarine (supplied by Yukijirushi Nyugyo) was placed in
the case and heated for 30 seconds by an electronic oven
(Type NE-A740 supplied by Matsushita Denki Sangyo).
After the heating, the case was allowed to stand still at
room temperature, and the number of days required for
the margarine to exude to the outer surface of the paper
layer was determined by the visual inspection.
A case prepared in the same manner as described
above was charged with a starting powder of a chocolate
cake (House Range Gourmet supplied by House Shokuhin)
and water, and cooking was carried out for 3 minutes and
30 seconds by using the same electronic oven as
described above. After the cooking, exudation of
the content to the outer surface was examined without
taking out the content from the case.
Similarly, a case prepared in the same manner as
described above was charged with a starting powder of
butter cake (House Range Gourmet*supplied by House
Shokuhin) and water, and cooking was carried out at a
set temperature of 190'C for 20 minutes in an oven. After
the cooking, exudation of the content to the outer
surface was examined without taking out the content from
'Trade-mark
CA 02311753 2000-07-13
- 24 -
the case.
The obtained results are shown in Table 3.
Example 7
The procedures of Example 6 were repeated in the
same manner except that the coating thickness of PMP
(III) used in Example 6 was changed to 20 yam and the
thickness of the coating layer of PET (I) was changed to
Vim. The obtained results are shown in Table 3.
15
25
35
CA 02311753 2000-07-13
- 25 -
Table
Example 6 Example 7
Structure
inner layer PMP(III)(15) PMP(III)(20)
intermediate PET(I) (15) PET(I) (10)
layer
outer layer milk carton milk carton
paper (300) paper (300)
Number of days for exudation was same as in
exudation of not caused for Example 6
margarine 20 days, and
test was stopped
Number of days for same as in
exudation of ditto Example 6
chocolate cake
(electronic oven)
Number of days for ditto same as in
exudation of Example 6
butter cake (oven)
Note Unit of each parenthesized value is jam.
CA 02311753 2000-07-13
67616-176 _-
- 26 -
Example 8
PMP (III) in Comparative Example 2 and PMP (I) in
Example 1 were independently melted in extruders having
a screw diameter of 65 mm, and the melts were laminated
on a milk carton paper having a base weight of 290 g/mm2
by using a coextrusion two-layer die. The total coating
thickness was 30 Vim, and each of the coating layers had
a thickness of 15 Vim. A case having a size of 10 cm x
cm x 5 cm (depth) was prepared from the obtained
10_ laminated paper so that the coating layer was located on
the inner surface.
Then, weighed 40 g of commercially available
margarine (supplied by Yukijirushi Nyugyo) was placed in
the case and heated for 30 seconds by an electronic oven
(Type NE-A740 supplied by Matsushita Denki Sangyo).
After the heating, the case was allowed to stand still
at room temperature, and the number of days required for
the margarine to exude to the outer surface of the paper
layer was determined by the visual inspection.
A case prepared in the same manner as described
above was changed with a starting powder of a chocolate
cake (House Range Gourmet supplied by House Shokuhin)
and water, and cooking was carried out for 3 minutes and
seconds by using the same electronic oven as
25 described above. After the cooking, exudation of the
content to the outer surface was examined without taking
out the content from the case.
Similarly, a case prepared in the same manner as
described above was charged with a starting powder of
30 butter cake (House Range Gourmet*supplied by House
Shokuhin) and water, and cooking was carried out at a
set temperature of 190°C for 20 minutes in an oven.
After the cooking, exudation of the content to the outer
surface was examined without taking out the content from
the case.
*Trade-mark
CA 02311753 2000-07-13
- 27 -
The obtained results are shown in Table 4.
Example 9
The procedures of Example 8 were repeated in the
same manner except that a crystalline copolymer of 4-
methyl-1-pentene with octadecene (octadecene content of
4 % by weight) hereinafter referred to as "PMP (III)"1
having a melting point of 229°C, MFR of 10 min and an
initial flexural modulus of elasticity of 8000 kg/cm2
was used instead of PMP (I) used in Example 1. The
obtained results are shown in Table 4.
Comparative Example 6
The procedures of Example 8 were repeated in the
same manner except that PMP (III) used in Example 2 was
used for both of the coextruded layers. The obtained
results are shown in Table 4.
25
35
CA 02311753 2000-07-13
- 28 -
Table 4
Example 8 Example 9 Comparative
Example 6
Structure
inner layer PMP(III) PMP(I) PMP(III)
( i 5 pm ) ( 15 ( 15 ;gym
;~m )
)
intermediate PMP(I) PMP(IV) PMP(I)
layer ( 15 ~.un ( 15 ( 15 run
) ;am )
)
paper
Number of days exudation same in
was as
for exudation not caused Example 8
of
margarine for 20 days,
and test was
stopped
Number of days ditto same in 3
as
for exudation Example 8
of
chocolate cake
(electronic oven)
Number of days ditto same in 5
as
for exudation Example 8
of
butter cake
(oven)
Note Unit of each parenthesized value is jxm.
