Note: Descriptions are shown in the official language in which they were submitted.
r`\ ~
~1~)4~)5~
The present invention relates to a heat-adhesive
laminated film having excellent heat resistance. ~lore particularly,
it relates to a heat-adhesive laminated film produced by laminating
a film of plastic material having excellent heat resistance,
such as a polyester, polyamide or polycarbonate film or a metal
foil, such as aluminum or copper foil, with a film of a resin `
comprising predominantly a block copolyester.
The subject matter of this specification is closely
related to that of copending Canadian patent application
Serial No. 191,606 filed on February 1, 1974, by the applicants
of this application.
Hitherto, heat resistant film such as polyester film,
polyamide film or polycarbonate film and metal foil such as
a]uminum foil or copper foil have been variously used for food
packaging? insulating material, tape or the like due to their ~ ;
excellent mechanical,electrical and chemical properties (e.g. ~;
chemical proofing, oil resistance and water proofing), heat
j,,
resistance and coldproofing. Usually, they have been used in
the form of laminates partially or wholly with each other or with
20 other plastic film or metal foil. ~owever, such plastic film `~
j
or metal foil per se has no heat-adhesive property and
therefore there have been proposed methods for giving them
such property. Among these methods laminating a thermoplastic ;
resin on the surface of the film has been preferred because such
resin can be adhered by heating under pressure for short time and
does not give rise to the problem of pot life. Due to this poor
heat resistance of the thermoplastic resin, however, when the
thermoplastic resin is laminated, the inherent heat resistance
of polyester film, polyamide film or polycarbonate film can not
be effectively utilized.
"
sz~ ~
Accordingly, there has been a need for a film (laminate)
having both of excellent heat resistance and excellent heat adhe-
sion for use in the packaging and electrical fields.
In the packaging field for medical instruments and foods,
the packaged material is usually sterilized by heating at above
100C, usually at 110 to 120C. For complete sterilization-
it is necessary to heat at about 120C for 15 or more minutes in
- la -
!~, ,,J
, ~ ' . . " ''
1C14~5;~
- a retort pouch (pressure vessel for sterilization). In addition
to the steriliza~lon step a further treatment in the retort pouch
is required for about same time before and after the sterilization.
It would therefore be desirable if the sterilization time could
be shortened in order to rationalize the retort treatment and
for reducing the cost. The heat sterilizatic.~ procedure should
be carried out at sufficiently high temperature and for enough
time to kill the spores of bacteria which have high heat
- resistance, and the relation between the temperature and time
sufficient for killing the spores is shown by the "longarithmic
rule". That is, the number of killed spores varies longarithmically
in accordance with change of temperature and the tlme. Accordingly,
when the sterillzation temperature ls raised, the sterilization
time can be largely reduced.
Conventionally, the film used for forming a retort
pouch has been a laminated (two layer) film comprising polyethylene
film and polyester film, polyamide film or polycarbonate film, ` `~
or a three layer film having aluminum foil between the two layers
of the above laminated film. In these laminated films, the
polyester film, polyamide film and polycarbonate film has been
used for the purpose of affording mechanical strength and
providing heat resistance and coldproofing of the laminate, ~he
metal foil such as aluminum foil has been used as a barrier
mainly from oxygen, steam, light and ultraviolet rays, and the
polyethylene film has been used mainly for the purpose of giving
heat-sealing characteristics to the laminate. A container made
from these laminating materials must withstand the high temperature
and high pressure in the retort sterilization step, but in fact
may barely tolerate the conventional retort sterilization
temperature of about 120C as far as the polyethylene film is
concerned. However, for rationalization of the retort treatment,
a still higher sterilization temperature is desirable, and
therefore, there has been a need to develop an improved heat
- 2 -
104~5Z0 ~
adhesive laminate capable of tolerating higher sterilization
temperatures, such as 130~C or more.
In addition, for electrical parts there have been used
laminates of a metal foil such as alumlnum foil or copper foil
with polyester film, polyamide film or polycarbonate film for
electrical heating elements and printed circuit, and the films and
; foils are required to have heat adhesion and heat resistance
properties.
These requirements are explained in detail below.
Generally, for providing excellent heat adhesion proper~ies in
a film, the heat adhesive resin layer of the Pilm should:
(1) be able to be liquefied by heating and thereby
flowed every nook and corner of the surface of the ob~ect to which
it is to be adhered,
(2) have good affinity with the object to which it is
to be adhered, exhibit good thermodynamic wetting, and stimulate
the intermolecular forces between the resin and the object,
(3) capable of being solidified rapidly,
(4) have a small residual stress, and
(5) have such good flexibility that stress concentration
does not occur when the layer is destroyed, and simultaneously
exhibit a good enough cohesive force to resist to destruction. ;
The property to resist to desctruction means that after the
laminated film is adhered or heat-sealed, the film must satisfy
the condition mentioned in item t5) at high temperature when
it is treated at high temperature. Moreover, the laminated film
is generally used over a wide range of temperature from high
temperatures to room temperature, and therefore the resin must
have such good dynamlc property as to satisfy the condition
mentioned in item (5) over a wide range of temperatures from high
temperatures such as 130C or more to low temperatures such as
room or lower temperature.
Thus, among the above-mentioned conditions (1) to (5),
the condition (5),
104~)~Z(~
i.e. the dynamic property, plays a most important role in giving
to the laminated film excellen~ adhesion strength and heat-seal
;: .:.,
strength over a wide range of temperature and the dynamic property
is effected largely by the thermic property of the adhesive resin.
That is, the adhesive resin layer preferably has a glass transition
~: .: .:
point of less than room temperature and also a melting point of
more than 130C as thermic properties, for affording the laminated
ilm such excellent adhesion strength or heat-seal strength over
a wide range of temperature. ~ -
It has now been found that for obtaining a film having
the desired excellent adhesion strength and heat-seal strength `
over the indicated temperature range, the dynamic properties of
the adhesive resln layer must satisfy the fol1owing conditlons -
at 20C and 130C. That is, when measured at a crosshead speed
of 30 cm/minute, it has a Young's modulus ~ satisfying the -
relationship: ~
. .
107 (dyne/cm2) < ~ < 101 (dyne/cm2)
and a breaking elongation (~/Qo) X 100 (a rate of elongation to
the initial length):
(~/Qo) X 100 > 40 (%)
When the adhesive resin layer has a Young's modulus :
of 10 dyne/cm2 or more, the adhesive resin layer becomes hard
and glass-like, and thereby surface stress concentration can
occur to give a product having poor adhesion strength or heat- -
seal strength. On the other hand, when the adhesive resin layer
has a Young's modulus of 107 dyne/cm2 or less, the layer becomes
soft and can not retain sufficiently good cohesive force to
resist to destruction and does not show excellent adhesion
strength or heat-seal strength even if the breaking elongation
is more than 40 %. In addition, when the adhesive resin layer
has a breaking elongation of 40 % or less, the layer is not
tough enough to resist ~o destruction and does not have excellent ~-
adhesion strength or heat-seal strength either, even if the Young~s
.
- 4 -
~i4~15ZO ~
modulus is in a range of 10 (dyne/cm ) ~ ~ ~ 10 (dyne/cm2).
It is preferable that the adhesive resin layer should
show a Young's modulus and breaking elongation in the above range
even at temperatures above 130C.
Accordingly, the invention provides a heat-adhesive
laminated film comprising a base film formed of a plastic film
formed of a polyester, polyamide, or polycarbonate or a metal
foil selected from aluminum and copper foils, and a film of
a resin laminated to one or both sides thereof said resin com-
prising predominantly a block copolyester comprising (1) acrystalline polyester segment having a melting point of at
least 200C. and a molecular weight of from 400 to 10,000,
and (2) a polymer segment of either a polyether or a polyester,
having a low melting point, a molecular weight of from 400
to 6,000 and present in a proportion of 5 to 80 percent by
weight of the block copolymer, said resin having a melting
point higher than 180C but lower than the temperature at
which the characteristics of the base film deteriorate and
having a Young's modulus ~(dyne/cm2) and a breaking elongation
(~Q/Qo) X 100 (%) when measured at 20C and 130C which satisfy,
respectively, the Eollowing relationships:
107 (dyne/cm2) ~ ~ < 101 (dyne/cm2) and
(~Q/Qo) X 100 > 40 (%).
The laminated film of the invention can be produced
by laminating a block copolyester film on a base film comprising
a plastic film or a metal foil.
The plastic film used as the base film may be formed
of polyester (e.g. polyethylene terephthalate, poly(ethylene
terephthalate/ethylene isophthalate), polytetramethylene tere- ;
phthalate, or polyethylene-1,?-diphenoxyethane~4,4'-dicarboxylate),
a polyamide (e.g. nylon 6, nylon 66, nylon 6/10, or polyxylylene
~ - 5 -
104052~
.
adipamide), a polycarbonate (e.g. 4~4'-dihydroxydiphenyl-2,2-
propane, i.e. bisphenol A), a copolymer formed predominantly
from the monomers of any of the above polymers, or a mixture
of any of these polymers or copolymers with another polymer
having similarly excellent or superior heat resistance. The
plastic film may be non-oriented film, uniaxially oriented film,
or biaxially oriented film, but biaxially oriented film is
particularly preferred. The plastic film may include one or
more other additives such as an antistatic agent, a lubricant,
: ' ' '
"' ':.
,
- 5a -
' . '.
:.
104~S2~
a haze preventing agent, a plasticizer, a stabi~izer, an anti-
blocking agent, or a colorant. Suitable metal foils include
aluminum and copper foils. The base film used in the present
invention preferably has a melting point of 200C or more.
The block copolyester to be laminated on the base
film comprises a crystalline polyest~r segment having
a high melting point and a polymer segment having a low melting
point and a molecular weight of 400 or more. As mentioned above,
the block copolyester has a melting point higher than 180C but
lower than the temperature at which the characteristics of the
base film deteriorate, and further has the dynamic properties
(when it is distorted at 20C and 130C at a crosshead speed
of 30 cm/minute) of Young's modulus E (dyne/cm2) and a breaking
elongatlon (~Q/Qo) X 100 (%) whlch satisfy the following
relationships:
(dyne/cm ) < E < 10 (dyne/cm ) and
(QQ/Qo) X 100 > 40 (%)
The temperature at which the characteristlcs of the base fllm
deteriorate means the temperature at which the dynamic properties
of the base film deteriorate, when the base film comprises a
polymer havlng excellent heat reslstance such as a polyester,
polyamide or polycarbonate, and this temperature will usually
be about 20C lower than the meltlng point of the polymer (base
film). When the base film comprises a metal foil, the temperature
will be about 300C, since the characteristics of metal foil
only change at higher temperature.
The component of the crystalline polyester segment may
be one which would have a melting point of 200C or more if a --~
polymer having fiber-forming properties were to be produced
from the component alone. An example of such a crystalline
polyester segment is one comprising an aromatic polyester unit -
having a bond in the para position, such as an ethylene tere-
, ~. . .
phthalate unit, tetramethyle~e terephthalate unit or the like as
"~ ~
,' .
~4~52 [)
the main compo`nent, preferably 70 or more % by weight of ethylene
terephthalate unit or tetramethylene tetraphthalate unit. It
may partially contain a dibasic acid component, such as isophthalic
acid, adipic acid, sebacic acid, or dodecanoic acid. The
crystalline polyester segment having a high melting point
has a molecular weight of 400 to 10,000.
The polymer segment having a low melting poin~ may
be substantially amorphous in the block copolyester. Examples
of polymer segments having a low melting point include polyethers,
aliphatic polyesters and polylactones. The polymer segment
usually has a molecular weight of 400 to 6,000, preferably
700 to 3,000. The ratio of the amount of polymer segment having
a low melting point in the block copolyester is preferably in
the range of 5 to 30 % by weight, more preferably from 10 to
60 % by weight, and most preferably from 20 to 50 % by weight.
Examples of suitable polymer segments having a low
melting point include polyethylene oxide glycol, polytetramethylene
oxide glycol, polyethylene adipate, polyethylene dodecanoate,
polyneopentyl adipate, polyneopentyl sebacate, polyneopentyl
dodecanoate, poly(e-caprolactone) and polypivalolactone.
Examples of the block copolyester include polyethylene
terephthalate/polyethylene oxide block copolymer, polytetramethylene
terephthalate/polyethylene oxide block copolymer, polyethylene
terephthalate/polytetramethylene oxide block copolymer,
polytetramethylene terephthalate/polytetramethylene oxide block
copolymer, polyethylene terephthalate/poly--caprolactone block
copolymer, polytetramethylene terephthalate/poly-~-caprolactone
block copolymer polyethylene terephthalate/polypivalolactone
block copolymer, polyethylene terephthalate/polyethylene adipate
block copolymer, polyethylene terephthalate/polyneopentyl sebacate
block copolymer, polytetramethylene terephthalate/polyethylene
dodecanoate block copolymer, polytetramethylene terephthalatet
polyneopentyl dodecanoate block copolymer polyethylene terephthalate~
, , ~ . ..
104~52~
isophthalate/polytetramethylene oxide block copolymer and
polytetramethylene terephthalate-isophthalate/polytetramethylene
oxide block copolymer.
The laminated film of the in~entlon may be produced
by an extrusion lamination method, i.e. by melt-extruding the
block copolyester and laminating it on the base Eilm, or by a
dry lamination method, i.e. by applying an adhesive to either
the base film or the block copolyester film, drying it and then
laminating the two together. When the extrusion lamination
method is used, the block copolyester film may be directly
extruded and laminated on the base film, or optionally an
adhesive may be applied to the base film and dried before the
extrusion and lamination of the block copolyester fil~m. The
laminated film may be also produced by applying a block copoly-
ester solution on the base film by gravure roll coating,
reverse~roll coating, rod coating or spray coating, and drying
to remove the solvent.
The base film and the block copolyester may each have
various thicknesses. The suitable thickness of each thereof
~ay be chosen according to the intended utility of the laminated
Pilm and the conditions of use thereof. However, the thickness
of the base film is preferably 10 ~ or more, particularly 10 to ,;~
500 ~, more particularly 10 to 30 ~ and that of the block
-: .
copolyester film is preferably 30 ~ or more, particularly 30
. .
to 500 ~, more particularly 30 to 100 ~.
In the laminated film of the invention, other plastic `~
; film or metal foil may be optionally laminated on the outside
of the base film or between the base film and the block copoly-
ester film, or any other resin may be optionally coated thereon,
or further there may be printed thereon.
The laminated film of the present invention can be
heat-sealed without losing its dynamic properties. It presents
' ', . .:
- 8 -
.,
.. , . ~ .. . . . . .... . . . . . .
S20
an attractive appearance and has excellent heat-seal strength
over a wide range of temperature from below room temperature
to high temperature such as more than 130C.
Moreover, the laminated film of the invention has
excellent tear strength, pinhole resistance, impact strength,
wear resistance, blocking resistance and oil resistance, and is
furthermore nontoxic.
The present inveniton is illustrated by the following
Examples in which parts are by weight, and the tests were
carried out as follows:
~1) Young's modulus and breaking elongation
The text material was melted, made into film and allowed
to cool. The test film thus produced was cut into strips 1 cm
in width and then allowed to stand at a prescribed temperature
J~ r~
for 5 minutes using Tensilon (UTM-III type, made by Toyo Seiki
K.K.). The load-elongation diagram was drawn at a gauge length
of 1.5 cm and at a rate to pulling of 30 cm/minute, and thereby
the Young's modulus (dyne/cm2) and the breaking elongation
(~Q/Qo) X 100 (%) were calculated.
(2) Melting point
~y using a micromelting point apparatus (made by
Yanagimoto Seisakusho), the temperature was raised at a rate
of 1C/minute and the point was checked when the film became dark
when observed by a polarmicroscope.
(3) Heat-seal strength of hhe laminated film
Tensilon (UTM-III type, made by Toyo Seiki K.K.) was
used. The heat-sealed laminated film was allowed to stand at
a prescribed temperature for 5 minutes and then subjected to
T-peel at a crosshead speed of 30 cm/minute.
Example 1
A stainless steel reactor was charged with dlmethyl
terephthalate (10,000 parts), 1,4-butanediol (5,~00 parts) and
titanlum tetrabutoxide (6 parts) and the mixture was subjected
9 ~
.... . ...
.. .
1(~4~5ZO
to ester exchange reaction at 140 to 230C in nitrogen gas.
The reaction mixture was added to a mixture of polytetramethylene
oxide h,aving molecular weight of 1,000 (3,800 parts) and Irganox
V 'I )'d l ~ hl D ~
: A . lolo (antioxidant, made by Ciba-Geigy; 30 parts) which was
preheated at 230C. The pressure in the reactor was gradually
reduced with increasing temperature, and then the mixture was
subjected to polycondensatlon reaction at 245C, at reduced -~
pressure of about 0.1 mmHg for 2 hours with agitation. The
polytetramethylene terephthalate/polytetramethylene oxide block
~- 10 copolymer thus obtained was cooled with water and then pelleti~ed
to give a cylindrical pellet having 3 mm in diameter and 3 mm
in length which was dried at 80C, at about 0.1 mmHg for 5 hours.
The reduced viscosity of the copolymer thus obtalned was 1.7~ dl/g,
which was measured at a concentration of 0.2 g/dl in phenol/
tetrachloroethane: 6/4 by weight and at 30C. The melting point
thereof was 215C.
The block copolyester was heat-pressed at 230C,
4 kg/cm2 for 30 seconds using a iron plate coated with poly-
! tetrafluoroethylene and then allowed to cool to give a film.
', 20 The dynamic properties of the film thus obtained were measured ` - ;~
at room temperature (20C), 130C and 160C.
~ s a base film there was used a biaxially oriented
polyethylene terephthalats film of 19 ~ in thickness, and as
an ad~esive there was used a 15 % (solids) solution of Vylon
,~
300 (made by Toyo Boseki K.K.)/Collonate L (made by Nippon
Polyurethane K.K.): 95/5 by weight solids in ethyl acetate``.
The adhesive was applied to the base film by gravure coater
,
(100 mesh X 40 ~), and the resultant product was passed through
a 2 m dryer at a rate of 30 m/mlnute, and a non-oriented block
copolyester film of 40 ~ in thickness was laminated thereon at
a nip temperature of 90 to 95C and a nip pressure of 5 kg/cm
by the dry lamination method. Two sheets of the lamlnatecl film
thus obtained were put togatller with the non-oriented block
...
. . , : .: .
4¢)52(;~
copolyester sides of both films facing each other, and then lt
was heat-sealed at 250C, 2 kg/cm for one second. The dynamic
properties of the block copolyester resin layer are shown in
Table 1, and the heat-seal strength of the laminated film are
shown in Table 2. For comparison, the dynamic properties and
heat-seal strength of polyethylene and random copolyester which
had similar melting point to-that of the present block copolyester
were measured. The results are also shown in Table 1 and Table 2,
respectively.
Comparative Examp].e 1
Example 1 was repeated except that the following
random copolyester was used instead of block copolyester.
The random copolyester was polyethylene terephthalate/
dodecane dicarboxylate: 80/20 by molar ratio produced by a
conventional ester exchange method from dimethyl terephthalate,
ethylene glycol and dodecanedicarboxylic acid. It has an
intrinsic viscosity of 0.695 dl/g which was measured in phenol/
1,1,2,2-tetrachloroethane: 6/4 by weight at 30C.
Comparative Example 2 -
,
Example 1 was repeated except that a high viscosity
'rrdde ~
A~ polyethylene (Hizex # 5600F, made by Mitsui Toatsu Chemicals
Inc.) lnstead of block copolyester.
Comparative Example 3
Example 1 was repeated except that a low viscosity
"~r~ "~
polyethylene (Sumikasen #F 702-2, made by Sumitomo Chemical
Co., Ltd.) instead of block copolyester.
The heat-sealing of the random copolyester of Comparative
Example 1 was carried out in the same manner as that of the
present block copolyester. The polyethylenes of Comparative
Examples 2 and 3 were heat-sealed as follows: Polyethylene
was melt-extruded and laminated in the thickness of 40 ~ on
biaxially oriented polyetllylene terephthalate film of 12 ~l in
thickness. Two sheets of the laminated film thus obtainecl werc
~O~S2~
put together with the polyethylene layer sides of both films
facing each other, and t.hen heat-sealed at 250C, 2 kg/cm2 for
one second.
. Example _ _ ~ reak~.n~
nu~ber of Melting Young's ~odulus E ~dyne/cm ) ~longatlon
adhesive point . (~ o)X 100 (~)
. resin (C) I .
la~yer 20C 130C 160C 20C1130CI160C
Ex. 1 215 2.0 X 109 5.0 X 10~ ~,0 X 10~ 400 400 300
Ex. i 215 7,6 X 10~' ~.0 X 10~ 2.7 X 10~5o 20 10
Comp. 132 2.7 X 109 2.0 X 10~ * 200 100 * ~ :
Comp 110 3.3 X 109 . * 3 * i
'~ .
.*~ Impossible to me~sure because the material had melted, :
Table 2 ~ :
,:
. . _ . ,:
Heat-seal streneth (~/cm)
Example number o~ . ..
la~inated film 20C 160C
. _ ' " ~,
~xample 1 4000 500
Comp. ~xample 1 . 1000 50
Comp. ~xample 2 2400 0 . .
Comp, Example ~ 1500 _ _
;
. ..
As will be clear from the above results, the laminated
film having the block copolyester resin layer of the present .-~
invention showed excellent heat-seal strength not only at room .
temperature but also at the high temperature of 160C, while on
the other hand, the laminated film of the Comparative Examples
did not show such excellent heat-seal strength at high
temperature. ~ 2
:
~ 1~4~35ZO
_xample 2 ;;
To biaxially oriented polyethylene terephthalate film
of 12 ~ in thickness was applied isocyanate anchoring agent
(EL 250, made by Toyo Ink K.K.; concentration: 4 %) by miller
roll method, and the resultant was passed through 2 m dryer
wherein it was dried by hot-air of 110C. On the coating layer
the block copolyester of Example 1 was melt-extruded at resin
temperature of 230C and laminated in thickness of 40 ~ at a
:- rate of 40 m/minute. The laminated film thus obtained was
heat-sealed, of which the heat-seal strength was measured in
the same manner as described in Example 1. The heat-seal
strength was 3600 g/cm at room temperature and 550 g/cm at 160C.
;~ Example 3
; A stninless steel reactor was charged with dimethyl
terephthalate (6,200 parts), 1,4-butanediol (4,000 parts) and
tltanium tetrabutoxide (5.5 parts) and the mixture was subjected
to ester exchange reaction at 140 to 230C in nitrogen gas. The
reaction mixture was added to a mixture of polytetramethylene
` oxide having a molecular weight of 1,000 (5,000 parts) and
d ~r/~ " ~
O Sumilizer BHT (antioxidant, made by Sumitomo Chemical Co., Ltd.;23 parts) which was preheated at 230C. The pressure in the
reactor was gradually reduced while raising the temperature,
and then the mixture was subjected top~ycondensation reaction
at 245C, at reduced pressure of about 0.1 mmHg for 2 hours ~
with agitation to give polytetramethylene terephthalate/poly- r
tetramethylene oxide block copolymer. The block copolymer thus
obtained was dried at 80C, at reduced pressure of about 0.1 mmHg
for 5 hours. The reduced viscosity (nsp/C) of the copolymer was
1.99 dl/g, which was measured at a concentration of 0.2 g/dl
in phenol/tetrachloroethane: 6/4 by weight and at 30~C. The
melting point thereof was 205C.
Tlle block copolyester was heat~p~essed at 230C,
4 kg/cm2 for 30 seconds by using an iron plate coated with
~3 ~:~
sz~
polytetrafluoroethylene and the allowed to cool to give a film.
The dynamic properties of the film thus obtained were measured
at room temperature (20C), 130C and 150C. The results are
shown in Table 3.
. ~.- .
: .:
Tabl e ~ ~ .
- , 2~reak~n~ elon~ation
Young~s modullls E (dyne/cm ) (~leO)x 100 (~o)
- - - - ~ ~ ~
20C 130C 150C 2~C 130~ 1 150C
_ _ _ .- ~:
1.0 X 109 3.5 X 10~ 2.0 X 108 500 400 300 ~
_ _ _ _ `, :' '.
As a base film there was used a biaxially oriented ~ ;
polyethylene terephthalate film of 19 ~ in thickness, nylon 66
.: . .
film of 20 ~ in thickness or polycarbonate film of 20 ~ in
thickness, and as an ad,hesive there was used a 15 % (solids) ,
~ r~
solution of Vylon 300 (made by Toyo Boseki K.K.)/Collonate L
"~d"~ar~'
(made by Nippon Polyurethane K.K.): 95/5 by weight solids in
ethyl acetate. The adhesive was applied to the base film by
- gravure coater (100 mesh X 40 ~), the resultant was passed
through 2 m dryer at a rate of 30 m/minute, and thereon a non-
oriented block copolyester film of 40 ~ in thickness was
laminated at nip temperature of 90 to 95C and at nip pressure
of 5 kg/cm2 by dry lamination method. Two sheets of the ~
laminated film thus obtained were put together with the non- -
oriented block copolyester sides of both films facing each other~
and then it was heat-sealed under the following conditions:
When polyethylene terephthalate film was used as the ,'
base film: ;~
Temperature: 250C, Pressure: 2 kg/cm2/second ~
When nylon 66 film was used as the base film: ,~,
Temperature: 240C, Pressure: 2 kg/cm2/second
When polycarbonate obtained from bisphenol A was used '
34~5;~0
as the base film: ~-
Temperature: 220C, Pressure: 2 kg/cm2/second
- The heat seal strength in each case are shown in
Table 4.
~L `! ; ;
_ _ _'. .
Temperature :
Base f ilm 20~C j 150C
_ ~' '
iolyethylene terephthalate ~000 (,~/cm) 500 (g/cm)
Nylon 66 2000 ~00
Polyc~rh onat e 2 800 '300
. . _ . ' .
Example 4
A stainless steel reactor was charged with dimethyl
terephthalate (6,200 parts), ethylene glycol (5,000 parts), zinc
acetate (5 parts) and antimony trioxide (3 parts) and the mixture
was subjected to ester exchange reaction at 140 to 230C in
nitrogen gas. The reaction mixture was added to a mixture of
polytetramethylene oxide having molecular weight of 1,000
` ~/ra~J~ "
(5,000 parts) and Irganox 1010 (antioxidant, made by Ciba-Geigy;
23 parts) which was preheated at 230C. The pressure in the
reactor was gradually reduced while raising the temperature, -~
and then the mixture was subjected to polycondensation reaction
at 245C, at reduced pressure of about 0.1 mmHg for 2 hours with
agltation. The reaction product was dried at 80C, at reduced ;`
pressure of about 0.1 mmHg for 2 hours. The reduced viscosity ;
(nsp/C) of the copolymer thus obtained was 1.59 dl/g, which was
measured at concentration of 0.2 g/dl in phenol/tetrachloroethane:
6/4 by weight and at 30C. The melting point thereof was 200C.
The block copolyester was heat-pressed at 230C,
4 kg/cm for 30 second by using an iron plate coated with
polytetrafluoroethylene and then allowed to cool to give a film.
52~
The dynamic properties of the film thus obtained were measured
at 20C, 130C and 150C. The results are shown in Table 5.
q~a~le ~ .
~:
_ . .
Young's modulus E (dyne/c~2) Break~ng elongatlon
l _
i 20~C 130C I 150C 20C1~0C I 150C
:~ ~ . ..
6.0 X 108 l2.5 X 10~ 1l.O ~ 10~ 600 400 300
. .
~s a base film there was used a biaxially oriented
-
~polyethylene terephthalate f ilm of 19 ~ in thickness, and as an
adhesive there was used a 15 % (solids) solution of Vylon 300
~ rd C/~ r~
d~ ~made by Toyo Boseki K.K.)/Collonate L (made by Nippon Poly- I
urethane K.K.): 9S/5 by weight solids in ethyl acetate. The
adhesive was applled to the base film by gravure coater (100 mesh
X 40 ~), the resultant was passed through 2 m dryer at a rate
of 30 m/minute, and a non-oriented block copolyester film of
40 ~ in thickness was laminated thereon at a nip temperature of
90 to 95C and nip pressure of 5 kg/cm by dry lamination method.
Two sheets of the laminated film thus obtained were put together
with the non-oriented block copolyester sides of both f ilms
facing each other, and then it was heat-sealed at 250C, 2 kg/cm2
for one second. The heat-seal strength of the film was 2,800 g/cm
: -.,: .
at room temperature and 200 g/cm at 150C.
Example 5 ;
:~ ~, , .
A stainless steel reactor was charged with dimethyl
terephthalate (6,000 parts), dimethyl isophthalate (2,000 parts),
1,4-butanediol (4,600 parts) and titanium tetrabutoxide (4.5
parts) and the mixture was subjected to ester exchange reaction
, at 140 to 230C in nitrogen gas. The reaction mixture was added
. .
to a mixture of polytetramethylene oxide having molecular weight
of 1,000 (3,000 parts) and Irganox 1010 (antioxidant, made by
Ciba-Geigy; 24 parts) whlch was p~reheated at 230C. The pressure
~ .
~146~5ZO
in the reactor was gradually reduced while raising the temperature,
and then the mixture was subjected to polycondensation reaction at
245C, at reduced pressure of about 0.1 mmHg for 2 hours with
agitation to give polytetramethylene terephthalate-isophthalate/
polytetramethylene oxide block copolymer. The reaction product
was dried at 80C, at reduced pressure of about 0.1 mmHg for
2 hours. The reduced viscosity (~sp/C) of the copolymer thus
obtained was 1.70 dl/g, which was measured at concentration of
0.2 g/dl in phenol/tetrachloroethane: 6/4 by weight and at 30C.
The melting point thereof was 185C.
The block copolyester was heat-pressed at 230C,
4 kg/cm for 30 seconds by using an iron plate coated with
polytetrafluoroethylene and then allowed to cool to give a film. ~
The dynamic properties of the film thus obtalned were measured ;
at room temperature, 130C and 160C. The results are shown
in Table 6.
Table 6
_ _ :~
2~eakin~ elonga-tion
Youn~ls ~odulus E (dyne/cm ) (~/eo~Y~ 100 (~)
_ .
20~ 130C 160C20C I 130C ~ 160~
_ .
2.0 X lo8 3,0 X 108 ~.0 X 107 600 3-oo 200
.
As a base film there was used a biaxially oriented
polyetllylene terephthalate film of 19 ~ in thickness, and as an
adhesive there was used a 15 % (solids) olution of Vylon 300
'`~r~d~l~a r~ " ~Sr~ "
(made by Toyo Boseki K.K.)/Collonate ~ (made by Nippon Poly-
urethane K.K.): 95/5 by weight solids in ethyl acetate. The
adhesive was applied to the base film by gravure coater (100 mesh
X 40 ~), the resultant was passed through 2 m dryer at a rate of
30 m/minute, and a non-oriented block copolyester fllm having
40 ~ in thickness was laminated thereon at a nip temperature
of 90 to 95C and at a nip pressure of 5 k~/cm by dry laminntion
~7
.~
. . .
: ~4~S2~) ~
method. Two sheets of the lamlnated film thus obtained were
put together with the non-oriented block copolyester sides of
both films facing each other, and then it was heat-sealed at 250C,
2 kg/cm2 for one second. The heat-seal strength of the film was
3,400 g/cm at room temperature and 200 g/cm at 160C.
Example 6
The block copolyester produced by Example 1 was melt-
extruded and laminated to a thickness of 50 ~ at a resin tempera-
ture of 235C and at a rate of 40 m~minute on a copper foil of
;
35 ~ thickness treated by electrolysis. Two sheets of the
laminated film thus obtained were put together with the resin
side of both films facing each other, and then it was heat-sealed
at 250C, 4 kg/cm2 for one second. The heat-seal strength of
the film was 3,500 g/cm at room temperature (20C) and 1,200
g/cm at 160C.
Example 7
~ On both sides of a biaxially oriented polyethylene
-~ terephthalate film of l9 ~ thickness was laminated the non-
:, :
oriented block copolyester of 30 ~ thickness produced in Example l
in the same manner as described in Example 1 by using the same -
adheslve as in Example 1 to give a three layer laminated film
comprising non-oriented block copolyester film (30 ~ in thickness),
biaxially oriented polyethylene terephthalate film (l9 ~ in
thickness) and non-oriented block copolyester film (30 ~ in
thickness). Two sheets of the film thus obtained were put together
and then heat-sealed at 250C, 4 kg/cm for one second. The
heat-seal strength of the film was 3,200 g/cm at room temperature
(20C) and 350 g/cm at 160C.
,"":
~8 `~:
:'
..
.; . .
.~. .- , .
