U.S. patent application number 12/632174 was filed with the patent office on 2010-04-08 for oxygen-absorbing resin, oxygen-absorbing resin composition and oxygen-absorbing container.
This patent application is currently assigned to TOYO SEIKAN KAISHA, LTD.. Invention is credited to Yoichi Ishizaki, YOSHIHIRO OHTA.
Application Number | 20100087619 12/632174 |
Document ID | / |
Family ID | 38048695 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100087619 |
Kind Code |
A1 |
OHTA; YOSHIHIRO ; et
al. |
April 8, 2010 |
Oxygen-Absorbing Resin, Oxygen-Absorbing Resin Composition and
Oxygen-Absorbing Container
Abstract
Disclosed is an oxygen-absorbing resin which exhibits excellent
oxygen absorption performance even in the absence of a transition
metal catalyst. Specifically disclosed is an oxygen-absorbing resin
which is composed of a copolyester obtained by copolymerizing at
least the following monomers (A)-(C). Monomer (A): a dicarboxylic
acid or a derivative thereof having a carbon atom bonded to both
the structures (a) and (b) below and also bonded to one or two
hydrogen atoms, wherein the carbon atom is contained in an
alicyclic structure (a) a carbon-carbon double bond group (b) any
one of a functional group containing a heteroatom or a linking
group derived from such a functional group, a carbon-carbon double
bond group and an aromatic ring Monomer (B): at least one selected
from the group'consisting of a dicarboxylic acid having an aromatic
ring or a derivative thereof, and a hydroxycarboxylic acid having
an aromatic ring or a derivative thereof Monomer (C): a diol
Inventors: |
OHTA; YOSHIHIRO; (Kanagawa,
JP) ; Ishizaki; Yoichi; (Kanagawa, JP) |
Correspondence
Address: |
HOFFMANN & BARON, LLP
6900 JERICHO TURNPIKE
SYOSSET
NY
11791
US
|
Assignee: |
TOYO SEIKAN KAISHA, LTD.
Tokyo
JP
|
Family ID: |
38048695 |
Appl. No.: |
12/632174 |
Filed: |
December 7, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12123569 |
May 20, 2008 |
|
|
|
12632174 |
|
|
|
|
PCT/JP2006/322994 |
Nov 17, 2006 |
|
|
|
12123569 |
|
|
|
|
Current U.S.
Class: |
528/361 ;
528/271 |
Current CPC
Class: |
C08G 63/60 20130101;
B32B 27/36 20130101; Y10T 428/1341 20150115; Y10T 428/31786
20150401; C08G 63/553 20130101; Y10T 428/1352 20150115 |
Class at
Publication: |
528/361 ;
528/271 |
International
Class: |
C08G 63/06 20060101
C08G063/06; C08G 63/00 20060101 C08G063/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 21, 2005 |
JP |
2005336123 |
Jun 1, 2006 |
JP |
2006153644 |
Jul 11, 2006 |
JP |
2006190568 |
Claims
1-14. (canceled)
15. An oxygen-absorbing resin which is obtainable by copolymerizing
at least the following monomers (A') and (B') and has a glass
transition temperature in the range of -8 to 15.degree. C.: monomer
(A'): a monomer comprising a carbon atom bonded to both of the
following structures (a) and (b) and further bonded to one or two
hydrogen atoms, the carbon atom being contained in an alicyclic
structure: (a) a carbon-carbon double bond group; and (b) either a
heteroatom-containing functional group, a bonding group derived
therefrom, a carbon-carbon double bond group, or an aromatic ring;
and monomer (B'): a monomer comprising an aromatic ring.
16. The oxygen-absorbing resin according to claim 15, wherein the
monomer (A) is a dicarboxylic acid or a derivative thereof.
17. The oxygen-absorbing resin according to claim 15, wherein the
monomer (B') is at least one of a dicarboxylic acid comprising an
aromatic ring, a derivative thereof, a hydroxycarboxylic acid
comprising an aromatic ring, or a derivative thereof.
18-24. (canceled)
25. The oxygen-absorbing resin according to claim 17, wherein the
rate of the alicyclic structure derived from monomer (A') in the
oxygen-absorbing resin is 0.6 to 7.0 meq/g.
Description
TECHNICAL FIELD
[0001] The present invention relates to an oxygen-absorbing resin,
an oxygen-absorbing resin composition containing the same and an
oxygen-absorbing resin container prepared using the resin.
BACKGROUND ART
[0002] Presently, various plastic containers are used for packaging
because of their advantages such as light weight, transparency and
easiness of molding.
[0003] However, because an oxygen barrier property of the plastic
containers is lower than those of metal containers and glass
containers, the plastic containers have problems in that the
contents of the containers deteriorate due to chemical oxidation
and the action of aerobic bacteria.
[0004] For preventing these problems the plastic container walls
have a multi-layer structure in which at least one layer is made of
a resin having an excellent oxygen barrier property such as an
ethylene-vinyl alcohol copolymer. In addition, there are other
kinds of containers having an oxygen-absorbing layer for absorbing
oxygen remaining in the containers and also oxygen penetrating into
the containers from the outside. Oxygen absorbers (deoxidizers)
used for the oxygen-absorbing layer include, for example, those
mainly containing a reducing substance such as iron powder (see,
for example, Japanese Examined Patent Publication (JP KOKOKU) No.
Sho 62-1824).
[0005] A method in which an oxygen absorber such as iron powder is
incorporated into a resin and the resulting resin composition is
used as a material for the wall of a container used as a packaging
material shows a sufficiently high ability to absorb oxygen, but
the resulting resin composition has a color hue peculiar to the
iron powder. Therefore, said method is limited in its application
and cannot be used in the field of packaging in which transparency
is required.
[0006] Further, there have been disclosed, as a resin-based
oxygen-absorbing material, an oxygen-absorbing resin composition
comprising a resin having a carbon-carbon unsaturated bond and a
transition metal catalyst (see, for example, Japanese Un-Examined
Patent Publication (JP KOKAI) No. 2001-39475, Japanese Un-Examined
Patent Publication (JP KOHYO) No. Hei 8-502306 and Japanese Patent
No. 3,183,704) and an oxygen-absorbing resin composition comprising
a resin having a cyclic olefin (cyclohexene) structure and a
transition metal catalyst (in particular, a Co salt) (see, for
example, Japanese Un-Examined Patent Publication (JP KOHYO) No.
2003-521552 and Japanese Un-Examined Patent Publication (JP KOKAI)
No. 2003-253131). However, the former composition has a problem in
that the molecular chain of the resin is cleaved as the resin
absorbs oxygen and thus low molecular weight organic components are
generated as an odor component. On the other hand, the latter
composition comprises ring structures as the oxygen-absorbing
sites, and thus it could somewhat inhibit the generation of such
low molecular weight organic (odor) components, but there is a
tendency that the use of such a transition metal catalyst (a Co
salt) may easily result in the occurrence of reactions at sites
other than the expected oxygen-absorbing sites and this in turn
leads to the formation of decomposition products.
DISCLOSURE OF THE INVENTION
Problems that the Invention is to Solve
[0007] Accordingly, it is an object of the present invention to
provide an oxygen-absorbing resin which shows an excellent ability
to absorb oxygen even in the absence of any transition metal
catalyst.
Means for the Solution of the Problems
[0008] The present invention provides an oxygen-absorbing resin
which is a copolyester obtainable by copolymerizing at least the
following monomers (A)-(C):
monomer (A): a dicarboxylic acid or derivative thereof comprising a
carbon atom bonded to both of the following structures (a) and (b)
and further bonded to one or two hydrogen atoms, the carbon atom
being contained in an alicyclic structure:
[0009] (a) a carbon-carbon double bond group; and
[0010] (b) either a heteroatom-containing functional group, a
bonding group derived therefrom, a carbon-carbon double bond group,
or an aromatic ring;
monomer (B): at least one member selected from the group consisting
of dicarboxylic acids comprising an aromatic ring, derivatives
thereof, hydroxycarboxylic acids comprising an aromatic ring and
derivatives thereof; and monomer (C): diol.
[0011] The present invention also provides an oxygen-absorbing
resin which is obtainable by copolymerizing at least the following
monomers (A') and (B') and has a glass transition temperature in
the range of -8 to 15.degree. C.:
monomer (A'): a monomer comprising a carbon atom bonded to both of
the following structures (a) and (b) and further bonded to one or
two hydrogen atoms, the carbon atom being contained in an alicyclic
structure:
[0012] (a) a carbon-carbon double bond group; and
[0013] (b) either a heteroatom-containing functional group, a
bonding group derived therefrom, a carbon-carbon double bond group,
or an aromatic ring; and
monomer (B'): a monomer comprising an aromatic ring.
[0014] The present invention also provides an oxygen-absorbing
resin composition comprising the foregoing oxygen-absorbing
resin.
[0015] The present invention also provides an oxygen-absorbing
container comprising an oxygen-absorbing layer consisting of the
foregoing oxygen-absorbing resin or the foregoing oxygen-absorbing
resin composition.
EFFECTS OF THE INVENTION
[0016] The oxygen-absorbing resin and oxygen-absorbing resin
composition according to the present invention show an excellent
ability to absorb oxygen even in the absence of any transition
metal catalyst, and thus they could enable the realization of
oxygen-absorbing materials showing practically acceptable
oxygen-absorbing ability while effectively inhibiting the
generation of any low molecular weight odor component.
BEST MODE FOR CARRYING OUT THE INVENTION
[0017] The oxygen-absorbing resin according to the present
invention is a copolyester obtainable by copolymerizing at least
the following monomers (A)-(C):
monomer (A): a dicarboxylic acid or derivative thereof comprising a
carbon atom bonded to both of the following structures (a) and (b)
and further bonded to one or two hydrogen atoms, the carbon atom
being contained in an alicyclic structure:
[0018] (a) a carbon-carbon double bond group; and
[0019] (b) either a heteroatom-containing functional group, a
bonding group derived therefrom, a carbon-carbon double bond group,
or an aromatic ring;
monomer (B): either a dicarboxylic acid comprising an aromatic
ring, a derivative thereof, a hydroxycarboxylic acid comprising an
aromatic ring, or a derivative thereof; and monomer (C): diol.
[0020] The alicyclic structure of monomer (A) may be a heterocyclic
structure containing a heteroatom in the ring. Alternatively, the
alicyclic structure may be either a monocyclic or polycyclic one
and if it is a polycyclic ring structure, the rings other than
those containing the foregoing carbon atom may be aromatic rings.
The alicyclic structure is preferably a 3- to 12-membered
monocyclic or polycyclic structure, more preferably a 5- or
6-membered monocyclic structure and further preferably a 6-membered
monocyclic structure. The 3- and 4-membered cyclic structures have
a high strain energy, and thus they are liable to easily cause the
opening of rings to form a linear chain structure. Regarding a 7-
or more membered cyclic structure, the synthesis thereof becomes
more and more difficult as the size of the ring increases, and thus
it would be unfavorable for industrial use. Particularly, the
6-membered cyclic structures are stable from the viewpoint of
energy and can also be easily synthesized, and thus they are
preferable. Moreover, the foregoing alicyclic structure contains a
carbon atom bonded to both of the structures (a) and (b) and
further bonded to one or two hydrogen atoms, and preferably a
carbon double bond group of the structure (a) is contained in the
alicyclic structure.
[0021] The hetero atom-containing functional group or the bonding
group derived therefrom of the structure (b) includes for example a
hydroxyl group, carboxyl group, formyl group, amido group, carbonyl
group, amino group, ether bond, ester bond, amido bond, urethane
bond and urea bond. A functional group comprising an oxygen atom as
the hetero atom or bonding group derived therefrom is preferable,
and includes for example the hydroxyl group, carboxyl group, formyl
group, amido group, carbonyl group, ether bond, ester bond, amido
bond, urethane bond and urea bond. The carboxyl group, carbonyl
group, amido group, ester bond and amido bond are more preferable.
The monomer (A) having these functional groups and bonding groups
can be prepared through relatively simple synthetic reactions, and
thus they are advantageous for industrial use.
[0022] The aromatic ring of the structure (b) includes for example
a benzene ring, naphthalene ring, anthracene ring, phenanthracene
ring and diphenyl ring. The benzene ring and naphthalene ring are
preferable, and the benzene ring is more preferable.
[0023] In addition, the carbon atom bonded to both of the
structures (a) and (b) and included in the alicyclic structure is
preferably bonded to one hydrogen atom. If one of the two hydrogen
atoms bonded to a carbon atom is replaced by for example an alkyl
group, and as a result the carbon atom is bonded to one hydrogen
atom, the resulting resin would be further improved in its ability
to absorb oxygen. In this connection, the derivative includes
esters, acid anhydrides, acid halides, substitution products and
oligomers.
[0024] The monomer (A) is preferably a derivative of
tetrahydrophthalic acid or tetrahydrophthalic anhydride, more
preferably a derivative of .DELTA..sup.3-tetrahydrophthalic acid or
.DELTA..sup.3-tetrahydrophthalic anhydride and further more
preferably 4-methyl-.DELTA..sup.3-tetrahydrophthalic acid or
4-methyl-.DELTA..sup.3-tetrahydrophthalic anhydride. The derivative
of tetrahydrophthalic anhydride can be quite easily synthesized by
the Diels-Alder reaction of maleic anhydride with a diene such as
butadiene, isoprene or piperylene. For example, products have been
manufactured by subjecting a mixture of
cis-3-methyl-.DELTA..sup.4-tetrahydrophthalic anhydride and
4-methyl-.DELTA..sup.4-tetrahydrophthalic anhydride, which are
prepared by reacting C.sub.5-cut of the naphtha mainly comprising
trans-piperylene and isoprene with maleic anhydride, to the
stereoisomerization reaction or the structural isomerization
reaction. These products are commercially available at a low price,
and thus they are preferable from the viewpoint of industrial use.
4-Methyl-.DELTA..sup.3-tetrahydrophthalic acid obtained by the
structural isomerization of
4-methyl-.DELTA..sup.4-tetrahydrophthalic acid is preferable as the
monomer (A). The other monomer (A) includes
exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride.
[0025] The diol of monomer (C) includes for example ethylene
glycol, diethylene glycol, triethylene glycol, polyethylene glycol,
propylene glycol, dipropylene glycol, polypropylene glycol,
1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,
1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol,
1,4-cyclohexane dimethanol, 2-phenylpropanediol,
2-(4-hydroxyphenyl)ethylalcohol,
.alpha.,.alpha.-dihydroxy-1,3-diisopropylbenzene, o-xylene glycol,
m-xylene glycol, p-xylene glycol,
.alpha.,.alpha.-dihydroxy-1,4-diisopropylbenzene, hydroquinone,
4,4-dihydroxydiphenyl, naphthalenediol or derivatives thereof.
Aliphatic diols such as diethylenediol, triethylenediol,
1,4-butanediol, 1,6-hexanediol are preferable, and 1,4-butanediol
is more preferable. If 1,4-butanediol is used, the resulting resin
has a high ability to absorb oxygen and a small amount of
decomposition products generated in the course of oxidation. One of
these diols or any combination of at least two of them may be
used.
[0026] If the combination of at least two of the above diols is
used, the combination of 1,4-butanediol and an aliphatic diol
having 5 or more carbon atoms is preferable, and the combination of
1,4-butanediol and 1,6-hexanediol is more preferable. A glass
transition temperature of the resulting oxygen-absorbing resin can
be easily controlled by using such combinations. If the combination
of 1,4-butanediol and an aliphatic diol having 5 or more carbon
atoms is used, the ratio of 1,4-butanediol to said aliphatic diol
is preferably 70:30 to 99:1 (mol %), and more preferably 80:20 to
95:5 (mol %).
[0027] The dicarboxylic acids comprising an aromatic ring or
derivatives thereof of monomer (B) include benzenedicarboxylic
acids such as phthalic anhydride, isophthalic acid and terephthalic
acid, naphthalenedicarboxylic acids such as
2,6-naphthalenedicarboxylic acid, anthracenedicarboxylic acids,
phenyl malonic acid, phenylenediacetic acids, phenylenedibutyric
acids, bis(p-carboxyphenyl)methane, 4,4-diphenyletherdicarboxylic
acids, p-phenylenedicarboxylic acids and derivatives thereof.
Dicarboxylic acids in which a carboxyl group is directly bonded to
an aromatic ring or derivatives thereof are preferable and include
phthalic anhydride, isophthalic acid, terephthalic acid,
2,6-naphthalenedicarboxylic acid and derivatives thereof. In this
connection, said derivatives include esters, acid anhydrides, acid
halides, substitution products and oligomers. One of these
dicarboxylic acids and derivatives thereof or any combination of at
least two of them may be used. In particular, it is preferred that
monomer (B) comprises terephthalic acid and further preferred that
monomer (B) comprises terephthalic acid and isophthalic acid.
[0028] The hydroxycarboxylic acids comprising an aromatic ring or
derivatives thereof of monomer (B) include 2-hydroxybenzoic acid,
3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,6-hydroxynaphthoic
acid, 2-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid,
4-hydroxyphenylacetic acid, 3-(4-hydroxyphenyl)butyric acid,
2-(4-hydroxyphenyl)butyric acid, 3-hydroxymethylbenzoic acid,
4-hydroxymethylbenzoic acid, 4-(hydroxymethyl) phenoxyacetic acid,
4-(4-hydroxyphenoxy)benzoic acid, (4-hydroxyphenoxy)acetic acid,
(4-hydroxyphenoxy)benzoic acid, mandelic acid, 2-phenyllactic acid,
3-phenyllactic acid and derivatives thereof. Hydroxycarboxylic
acids in which a carboxyl group and a hydroxyl group are directly
bonded to an aromatic ring or derivatives thereof are preferable
and include 3-hydroxybenzoic acid, 4-hydroxybenzoic acid and
derivatives thereof. In this connection, said derivatives include
esters, acid anhydrides, acid halides, substitution products and
oligomers. One of these dicarboxylic acids and derivatives thereof
or any combination of at least two of them may be used.
[0029] By copolymerizing monomer (B) in addition to monomers (A)
and (C), a copolyester preventing gelation and having a high degree
of polymerization can be obtained and thus extrusion moldability is
improved. In addition, the copolyester's Tg increases while its
crystallinity increases and thus the handling ability during the
molding is improved. That is, the resulting resin has a high
ability to absorb oxygen, a small amount of decomposition products,
and excellent extrusion moldability and handling ability.
[0030] The oxygen-absorbing resin according to the present
invention can be obtained by copolymerizing monomers (A) to (C).
The polymerization may be carried out according to any method known
to those skilled in the art. For example, the polymerization may be
carried out by interfacial polycondensation, solution
polycondensation, molten polycondensation or solid phase
polycondensation.
[0031] If the dicarboxylic acid comprising an aromatic ring or a
derivative thereof is used as monomer (B), the amount of monomer
(A) unit in the resulting resin is preferably 5 to 40 mol %, more
preferably 7.5 to 35 mol %, and further more preferably 10 to 30
mol % of all monomer units contained in the resin. In this case,
the amount of monomer (B) unit is preferably 10 to 45 mol %, more
preferably 15 to 42.5 mol %, and further more preferably 20 to 40
mol %. If said amounts are within the above ranges, the resulting
resin has improved handling ability and a high ability to absorb
oxygen.
[0032] If the hydroxycarboxylic acid comprising an aromatic ring or
a derivative thereof is used as monomer (B), the relative
proportions of monomers (A) and (B) may be appropriately selected
by those skilled in the art.
[0033] In addition to the above monomers (A) to (C), a monomer
selected from the group consisting of aliphatic dicarboxylic acids,
aliphatic hydroxycarboxylic acids, polyalcohols, polycarboxylic
acids and derivatives thereof may be copolymerized. Among them, in
particular, it is preferred that in addition to the above monomers
(A) to (C), monomer (D) selected from the group consisting of
aliphatic dicarboxylic acids, aliphatic hydroxycarboxylic acids and
derivatives thereof be copolymerized. One of these monomers or any
combination of at least two of them may be used. By copolymerizing
monomer (D), a glass transition temperature of the resulting
oxygen-absorbing resin can be easily controlled.
[0034] The aliphatic dicarboxylic acids and derivatives thereof
include oxalic acid, malonic acid, succinic acid, glutaric acid,
adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic
acid, undecane diacid, dodecane diacid, 3,3-dimethylpentane diacid
and derivatives thereof. Among them, adipic acid and succinic acid
are preferable, and adipic acid is particularly preferable.
[0035] The aliphatic hydroxycarboxylic acids and derivatives
thereof include glycolic acid, lactic acid, hydroxypivalic acid,
hydroxycaproic acid, hydroxyhexanoic acid and derivatives
thereof.
[0036] The polyalcohols and derivatives thereof include
1,2,3-propanetriol, sorbitol, 1,3,5-pentanetriol,
1,5,8-heptanetriol, trimethylolpropane, pentaerythritol, neopentyl
glycol, 3,5-dihydroxybenzyl alcohol and derivatives thereof.
[0037] The polycarboxylic acids and derivatives thereof include
1,2,3-propanetricarboxylic acid,
meso-butane-1,2,3,4-tetracarboxylic acid, citric acid, trimellitic
acid, pyromellitic acid and derivatives thereof.
[0038] The oxygen-absorbing resin according to the present
invention can be obtained as copolyester by copolymerizing monomers
(A) to (D). In this case, the amount of monomer (D) unit in the
resulting resin is preferably 1 to 25 mol %, more preferably 1 to
15 mol %, and further more preferably 2 to 10 mol % of all monomer
units contained in the resin.
[0039] A glass transition temperature of the oxygen-absorbing resin
according to the present invention obtained by copolymerizing
monomers (A) to (C) or monomers (A) to (D) is preferably in the
range of -8.degree. C. to 15.degree. C., more preferably in the
range of -8.degree. C. to 10.degree. C., and further more
preferably in the range of -5.degree. C. to 8.degree. C. If said
glass transition temperature is within the above range, the
oxygen-absorbing resin according to the present invention has an
excellent ability to absorb oxygen, especially in the early
stage.
[0040] The oxygen-absorbing resin according to the present
invention is an oxygen-absorbing resin which is obtainable by
copolymerizing at least the following monomers (A') and (B') and
has a glass transition temperature in the range of -8 to 15.degree.
C.:
monomer (A'): a monomer comprising a carbon atom bonded to both of
the following structures (a) and (b) and further bonded to one or
two hydrogen atoms, the carbon atom being contained in an alicyclic
structure:
[0041] (a) a carbon-carbon double bond group; and
[0042] (b) either a heteroatom-containing functional group, a
bonding group derived therefrom, a carbon-carbon double bond group,
or an aromatic ring; and
monomer (B'): a monomer comprising an aromatic ring.
[0043] Compounds having a polymerizable functional group or a
functional group which can be bonded to a polymer main chain and
the like can be used as monomer (A'). The polymerizable functional
group and functional group which can be bonded to a polymer main
chain include a hydroxyl group, carboxyl group, amido group, formyl
group, isocyanate group, epoxy group, vinyl group, acryl group,
methacryl group, halogen group and derivatives thereof. In
particular, monomer (A') is preferably dicarboxylic acids or
derivatives thereof. The dicarboxylic acids and derivatives thereof
can easily be polymerized as a raw material monomer of polyester,
polyamide or the like. In this case, the above-mentioned monomer
(A) can preferably be used as monomer (A').
[0044] Compounds having a polymerizable functional group or a
functional group which can be bonded to a polymer main chain and
the like can be used as a monomer comprising an aromatic ring of
monomer (A'). The polymerizable functional group and functional
group which can be bonded to a polymer main chain include a
hydroxyl group, carboxyl group, amido group, formyl group,
isocyanate group, epoxy group, vinyl group, acryl group, methacryl
group, halogen group and derivatives thereof. In particular,
monomer (B') is preferably dicarboxylic acids, derivatives thereof,
hydroxycarboxylic acids or derivatives thereof, and more preferably
dicarboxylic acids or derivatives thereof. The dicarboxylic acids
and derivatives thereof can be easily polymerized as a raw material
monomer of polyester, polyamide. In this case, the above-mentioned
monomer (B) can preferably be used as monomer (B').
[0045] The oxygen-absorbing resin according to the present
invention which can be obtained by at least copolymerizing monomers
(A') and (B') includes for example a resin in which a monomer (A')
unit and a monomer (B') unit are linked with each other through any
bonding group, a pendant type resin in which a monomer (B') unit is
linked with a polymer main chain comprising a monomer (A') unit
through any bonding group, a pendant type resin in which a monomer
(A') unit is linked with a polymer main chain comprising a monomer
(B') unit through any bonding group, and a pendant type resin in
which a monomer (B') unit and a monomer (A') unit are linked with
any polymer main chain through any bonding group.
[0046] The resin in which at least a monomer (A') unit and a
monomer (B') unit are linked with each other through any bonding
group includes polyesters, polyamides, polyethers and
polyurethane.
[0047] For example, by using monomers (B') in addition to (A') to
polymerize polyester, a resin preventing gelation during the
polycondensation and having high degree of polymerization can be
obtained and thus extrusion moldability is improved. In addition,
the resin's crystallinity increases while the blocking of resin
pellets is prevented and thus its handling ability during the
molding is improved. Furthermore, the resin has an improved
mechanical strength. That is, the resulting resin has a high
ability to absorb oxygen, a small amount of decomposition products,
excellent extrusion moldability, excellent handling ability and
excellent mechanical strength.
[0048] A glass transition temperature of the oxygen-absorbing resin
according to the present invention which can be obtained by
polymerizing at least monomers (A') and (B') is preferably in the
range of -8.degree. C. to 15.degree. C., more preferably in the
range of -8.degree. C. to 10.degree. C., and further more
preferably in the range of -5.degree. C. to 8.degree. C. If said
glass transition temperature is within the above range, the
oxygen-absorbing resin according to the present invention has an
excellent ability to absorb oxygen, especially in the early
stage.
[0049] When the oxygen-absorbing resin according to the present
invention is synthesized, a polymerization catalyst is not
necessarily used, but for example if the oxygen-absorbing resin
according to the present invention is polyester, it is possible to
use usual polyester polymerization catalysts such as
titanium-containing, germanium-containing, antimony-containing,
tin-containing and aluminum-containing polymerization catalysts. In
addition, it is also possible to use any known polymerization
catalysts such as nitrogen atom-containing basic compounds, boric
acid, boric acid esters, and organic sulfonic acid type
compounds.
[0050] Moreover, when polymerizing the foregoing monomers, various
kinds of additives such as coloration-inhibitory agents and/or
antioxidants such as phosphate-containing compounds can be used.
The addition of an antioxidant would permit the control of any
absorption of oxygen during the polymerization of the monomers and
the subsequent molding steps and this in turn permits the
inhibition of any quality-deterioration of the resulting
oxygen-absorbing resin.
[0051] The resin according to the present invention which can be
obtained by polymerizing raw materials including monomer (A) or
(A') possesses quite high reactivity with oxygen and thus the resin
can show actually acceptable oxygen-absorbing ability in the
absence of any transition metal catalyst without having been
exposed to any radiation. The rate of the alicyclic structure
derived from monomer (A) or (A') in the oxygen-absorbing resin
according to the present invention is preferably 0.4 to 10 meq/g.
The rate is more preferably 0.5 to 8.0 meq/g, further more
preferably 0.6 to 7.0 meq/g, and especially preferably 0.7 to 6.0
meq/g. If the rate is within the above ranges, the resulting
oxygen-absorbing resin has a practically acceptable ability to
absorb oxygen; the gelation of the resin during the polymerization
and molding is prevented; and the resin does not show any
significant hue change nor any significant strength reduction even
after the absorption of oxygen.
[0052] The number average molecular weight of the oxygen-absorbing
resin according to the present invention is preferably 1,000 to
1,000,000, and more preferably 20,000 to 200,000. If the number
average molecular weight is within the above ranges, it is possible
to form a film having an excellent processability and
durability.
[0053] One of the oxygen-absorbing resins according to the present
invention or any combination of at least two of them may be
used.
[0054] The oxygen-absorbing resin according to the present
invention can be used not only as starting resins for the melt
processing such as the extrusion molding and the injection molding,
but also as a paint after they are dissolved in a proper solvent.
When using the oxygen-absorbing resin as a paint, a curing agent
such as an isocyanate type one may be incorporated into the resin
to give a two-pack type adhesive for dry lamination.
[0055] The oxygen-absorbing resin according to the present
invention possesses quite high reactivity with oxygen, and thus the
resin can show actually acceptable oxygen-absorbing ability in, the
absence of any transition metal catalyst without having been
exposed to any radiation. The reactivity of the oxygen-absorbing
resin according to the present invention is initiated by heating
the resin during the synthesis of resin and/or the molding process
and the like. It is possible to increase the reactivity by
aggressively providing the resin heat or inhibit the reaction by
preventing the resin from being heated. For example, if the
reaction is inhibited, it is possible to increase the reactivity by
exposing the resin to radiation.
[0056] The radiation exposed to the oxygen-absorbing resin
according to the present invention includes particle beams such as
electron beams, proton beams and neutron beams, and electromagnetic
waves such as .gamma.-rays, X-rays, visible light rays and
ultraviolet light rays. Among them, light rays such as visible
light rays and ultraviolet light rays which are low energy
radiation are particularly preferable, and ultraviolet light rays
are more preferable. Conditions for the irradiation of the resin
with ultraviolet rays are preferably, for example, as follows:
UV-A, and an integral quantity of light ranging from 100 to 10000
mJ/cm.sup.2. The best time for the irradiation of the resin with
ultraviolet rays is not specifically restricted, but when using the
resin as a material for an oxygen-absorbing container, the
irradiation of the resin with ultraviolet rays is preferably
carried out after the molding of the resin into a container and the
charging of contents into the same, and immediately before the
airtight sealing of the container, to make effective use of the
oxygen-absorbing properties thereof.
[0057] The oxygen-absorbing resin of the present invention is
preferably free of any allyl hydrogen atoms other than those
present on the alicyclic structure. The allyl hydrogen atoms are
relatively easily eliminated and thus quite susceptible to oxygen
attack. If the resin has allyl hydrogen atoms on the linear chain
structures other than the alicyclic structure, low molecular weight
decomposition products are easily formed through the molecular
cleavage as the oxidation of the allyl-positions with oxygen
proceeds.
[0058] The resin of the present invention may comprise alicyclic
structures other than alicyclic structures which have high
reactivity and are derived from monomer (A) or (A'). In addition,
the above resin may comprise, in the other alicyclic structures,
relatively low reactive allyl hydrogen atoms which are not included
in the structures derived from monomer (A) or (A'). In the case of
these resins having the foregoing other structures, the allyl
hydrogen atoms present in the alicyclic structures having
relatively low reactivity are activated due to the chain transfer
of the radicals generated in the alicyclic structures which have
high reactivity and are derived from monomer (A) or (A'), and thus
this case is preferable since the oxygen-absorbing ability of the
resin is often improved.
[0059] Further, another type of thermoplastic resin may be
incorporated into the oxygen-absorbing resin of the present
invention to thus form an oxygen-absorbing resin composition. As
the thermoplastic resin, any type of thermoplastic resin may be
used. The thermoplastic resin includes for example low-density
polyethylene, medium-density polyethylene, high-density
polyethylene, linear low-density polyethylene, linear very
low-density polyethylene, polypropylene, poly-1-butene,
poly-4-methyl-1-pentene, polyolefins such as random or block
copolymers of .alpha.-olefins (such as ethylene, propylene,
1-butene and 4-methyl-1-pentene), cyclic olefin polymer (COP) and
cyclic olefin copolymer (COC), acid-modified polyolefins such as
maleic anhydride-grafted polyethylene and maleic anhydride-grafted
polypropylene, ethylene-vinyl compound copolymers such as
ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer,
ethylene-vinyl chloride copolymer, ethylene-(meth)acrylic acid
copolymer, ionic crosslinked products thereof (ionomers) and
ethylene-methyl methacrylate copolymer, styrenic resins such as
polystyrene, acrylonitrile-styrene copolymer and
.alpha.-methylstyrene-styrene copolymer, polyvinyl compounds such
as poly(methyl acrylate) and poly(methyl methacrylate), polyamides
such as nylon 6, nylon 66, nylon 610, nylon 12 and poly(m-xylylene
adipamide) (MXD6), polyesters such as polyethylene terephthalate
(PET), polybutylene terephthalate (PBT), poly(trimethylene
terephthalate) (PTT), polyethylene naphthalate (PEN),
glycol-modified polyethylene terephthalate (PETG), polyethylene
succinate (PES), polybutylene succinate (PBS), poly(lactic acid),
poly(glycolic acid), poly(caprolactone) and poly(hydroxy
alkanoate), polycarbonates, polyethers such as polyethylene oxide,
and mixtures thereof.
[0060] The thermoplastic resin is preferably polyethylene, and
especially preferably low-density polyethylene. The linear
low-density polyethylene which is a copolymer of ethylene and
1-alkene is more preferable. A film and sheet formed by blending
the oxygen-absorbing resin and the linear low-density polyethylene
have an excellent impact resistance. 1-propylene, 1-butene,
1-pentene, 1-hexene, 1-octene and mixtures thereof can be used as
the 1-alkene. The amount of 1-alkene in the copolymer is preferably
2 to 30 wt %, and more preferably 2 to 20 wt %.
[0061] Regarding the polymerization of ethylene and 1-alkene, the
resulting polymer may properly be selected from those prepared
using the conventional Ziegler-Natta catalyst or those prepared
using a single site catalyst so long as they possess the desired
molecular structures, but the polymerization which is carried out
through the use of a single-site catalyst would be able to prevent
the compositional ratio for copolymerization from varying
throughout all of the molecular weight components. As a result, the
resulting copolymer has a uniform molecular structure and thus if
the oxidation of the thermoplastic resin is induced by the chain
transfer of the radicals of the oxygen-absorbing resin, the
molecular chains constituting the copolymer are uniformly oxidized.
Therefore, this polymerization carried out in such a way is
preferable because the formation of any decomposition product due
to molecular breakage can be inhibited. A preferable catalyst
includes metallocene type ones. The other catalyst includes those
for the polymerization of olefins which are recognized to be
post-metallocene catalysts and, in particular, phenoxyimine
catalysts (FI Catalyst) are preferable.
[0062] It is preferred that the aforementioned linear low density
polyethylene is for example copolymers of ethylene and 1-olefin
prepared using a metallocene type catalyst as a polymerization
catalyst, such as copolymers of ethylene and 1-butene, copolymers
of ethylene and 1-hexene and copolymers of ethylene and 1-octene.
One of these resins or any combination of at least two of them may
be used.
[0063] The preparation of the foregoing resin through the
polymerization using a single-site catalyst may be carried out
using any industrially acceptable method, but it is preferably
carried out according to the liquid phase technique since this
technique has been most widely employed in this field.
[0064] One of the foregoing thermoplastic resins or any combination
of at least two of them may be used.
[0065] The foregoing oxygen-absorbing resin may comprise a filler,
a coloring agent, a heat stabilizer, a weathering agent, an
antioxidant, an age resister, a light stabilizer, a UV absorber, an
antistatic agent, a lubricating agent such as a metal soap or a
wax, and/or an additive such as a modifier resin or rubber.
However, if the foregoing oxygen-absorbing resin comprises an
antioxidant, the addition amount thereof is preferably restricted
to a small amount because the antioxidant may inhibit the oxygen
absorption reaction of the oxygen-absorbing resin. The amount of
the antioxidant in the oxygen-absorbing resin is preferably 100 ppm
or less, more preferably 10 ppm or less and especially preferably 0
ppm.
[0066] The amount of the oxygen-absorbing resin of the
oxygen-absorbing resin composition is preferably 3 to 80 wt %, more
preferably 10 to 60 wt % and further more preferably 20 to 50 wt %.
If the amount falls within the above ranges, the resulting
oxygen-absorbing resin composition has a practically acceptable
ability to absorb oxygen and the resin does not show any
significant hue change or any significant strength reduction even
after the absorption of oxygen.
[0067] The rate of the alicyclic structures present in the
oxygen-absorbing resin is preferably 0.1 to 10 meq/g and more
preferably 0.2 to 7 meq/g. If the rate falls within the above
ranges, the resulting oxygen-absorbing resin composition has a
practically acceptable ability to absorb oxygen and the resin does
not show any significant hue change or any significant strength
reduction even after the absorption of oxygen.
[0068] The oxygen-absorbing resin and the oxygen-absorbing resin
composition according to the present invention may further comprise
a plasticizer. The plasticizer defined herein includes all of those
which are compatible with the oxygen-absorbing resin according to
the present invention and have a property decreasing a glass
transition temperature.
[0069] The plasticizer includes phthalate ester plasticizers,
adipate ester plasticizers, azelate ester plasticizers, sebacate
ester plasticizers, phosphate ester plasticizers, trimellitate
ester plasticizers, citrate ester plasticizers, epoxy ester
plasticizers, polyester ester plasticizers and chlorinated paraffin
plasticizers. Specifically, the plasticizer includes dimethyl
phthalate, diethyl phthalate, dibutyl phthalate, di-2-ethylhexyl
phthalate, tributyl acetylcitrate, methyl acetylricinoleate,
di-2-ethylhexyl adipate, diisodecyl adipate, ethanediolmontanate,
1,3-butanediolmontanate, isobutyl stearate, poly(1,3-butylene
glycol adipic acid) ester, poly(propylene glycol adipic
acid-co-lauric acid)ester, poly(1,3-butylene glycol-co-1,4-butylene
glycol adipic acid)ester terminated with octyl alcohol. The amount
of the plasticizer in the oxygen-absorbing resin and the
oxygen-absorbing resin composition is preferably 0.2 to 20 wt %,
more preferably 0.5 to 10 wt %, and especially preferably 1 to 5 wt
%.
[0070] The oxygen-absorbing resin and the oxygen-absorbing resin
composition of the present invention may further comprise a variety
of additives such as a radical polymerization initiator and a
photosensitizer.
[0071] The radical polymerization initiator and photosensitizer
include those currently known as photopolymerization initiators
such as benzoins and their alkyl ethers such as benzoin, benzoin
methyl ether, benzoin ethyl ether and benzoin propyl ether;
acetophenones such as acetophenone,
2,2-dimethoxy-2-phenylacetophenone,
2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone,
1-hydroxycyclohexylphenylketone, 2-hydroxycyclohexylphenylketone
and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one;
anthraquinones such as 2-methylanthraquinone and
2-amylanthraquinone; thioxanthones such as
2,4-dimethylthioxanthone, 2,4-diethylthioxanthone,
2-chlorothioxanthone and 2,4-diisopropylthioxanthone; ketals such
as acetophenonedimethylketal and benzyldimethylketal; benzophenones
such as benzophenone; and xanthones. Such photo- and
radical-polymerization initiators may be used in combination with
one or at least two conventionally known and currently used
photopolymerization accelerator such as benzoic acid initiators or
tertiary amine initiators.
[0072] The other additives include fillers, coloring agents, heat
stabilizers, weatherable stabilizers, antioxidants, age resistors,
light stabilizers, ultraviolet light absorbers, antistatic agents,
lubricants such as metallic soaps and waxes, modifier resins or
rubber and these additives may be incorporated into the resin or
the resin composition according to any formulation known per se.
For example, the blending a lubricant into the resin or the resin
composition would improve the ability of a screw to bite the resin.
The lubricants generally used herein are metallic soaps such as
magnesium stearate and calcium stearate; those mainly comprising
hydrocarbons such as liquid paraffin, naturally occurring and
synthetic paraffin, microwaxes, polyethylene waxes and chlorinated
polyethylene waxes; aliphatic acid lubricants such as stearic acid
and lauric acid; aliphatic acid monoamide and bisamide lubricants
such as stearic acid amide, palmitic acid amide, oleic acid amide,
esilic acid amide, methylene bis-stearamide and ethylene
bis-stearamide; ester lubricants such as butyl stearate, hardened
castor oil and ethylene glycol monostearate; and mixtures thereof.
If the antioxidants is incorporated into the resin or the resin
composition, as mentioned above, it is preferred that the
incorporating amount of the antioxidants is restricted to the small
amount.
[0073] The oxygen-absorbing resin and the oxygen-absorbing resin
composition according to the present invention may be used for
absorbing oxygen present in an airtightly sealed package, in the
form of, for example, powder, granules or a sheet. Moreover, they
may be incorporated into a resin or rubber for forming a liner, a
gasket or a coating film in order to absorb the oxygen remaining in
a package. In particular, the oxygen-absorbing resin and the
oxygen-absorbing resin composition according to the present
invention are preferably used as an oxygen-absorbing container made
of a laminate which comprises at least one layer containing the
resin or the resin composition and one or a plurality of layers of
other resins.
[0074] The oxygen-absorbing container of the present invention
comprises at least one layer (hereunder referred to as an
"oxygen-absorbing layer") consisting of the foregoing
oxygen-absorbing resin and oxygen-absorbing resin composition.
[0075] The materials for forming the layers other than the
oxygen-absorbing layer, which constitute the oxygen-absorbing
container of the present invention, may appropriately be selected
from the group consisting of thermoplastic resins, thermosetting
resins, and inorganic materials such as metals and paper while
taking into consideration the modes of applications and required
functions thereof. For example, the thermoplastic resins listed
above in connection with the thermoplastic resins capable of being
incorporated into the oxygen-absorbing resin according to the
present invention, metal foils and inorganic vapor deposition films
can be mentioned.
[0076] Regarding the oxygen-absorbing container of the present
invention, an oxygen-barrier layer is preferably arranged at least
on the outer side of the oxygen-absorbing layer for the further
improvement of the effect of the oxygen-absorbing resin or the
oxygen-absorbing resin composition. Such a construction of the
container would allow the effective absorption of the external
oxygen possibly penetrating into the container and the oxygen
remaining in the container to thus control the oxygen concentration
in the container to a considerably low level over a long period of
time.
[0077] The oxygen-barrier layer may be prepared using a resin
having oxygen-barrier characteristic properties (oxygen-barrier
resin). Such an oxygen-barrier resin may be, for instance,
ethylene-vinyl alcohol copolymers (EVOH). Also usable herein as an
oxygen-barrier resin may be, for example, a saponified copolymer
obtained by the saponification of an ethylene-vinyl acetate
copolymer having an ethylene content ranging from 20 to 60 mole %
and preferably 25 to 50 mole % to a degree of saponification of not
less than 96 mole % and preferably not less than 99 mole %. Other
examples of such oxygen-barrier resins are
poly(m-xylyleneadipamide) (MXD6) and poly(glycolic acid). In
addition, a nanocomposite material formed by incorporating an
inorganic layered compound such as montmorillonite and the like
into the above oxygen-barrier resin, the other polyamide resin and
the like is preferably used.
[0078] In a case where the oxygen-absorbing container of the
present invention is, in particular, a film container such as a
pouch, usable as such an oxygen-barrier layer may be, for example,
a foil of a light metal such as aluminum; a metal foil such as an
iron foil, a tin plate foil, a surface-treated steel foil; a metal
thin film or a metal oxide thin film formed on a substrate such as
a biaxially oriented PET film by the evaporation method; or a
diamond-like carbon thin film. It is also possible to use a
barrier-coating film obtained by applying an oxygen-barrier coating
layer onto a substrate film such as a biaxially oriented PET
film.
[0079] A material constituting such metal thin films includes iron,
aluminum, zinc, titanium, magnesium, tin, copper and silicon, with
aluminum being particularly preferred.
[0080] A material constituting such metal oxide thin films includes
silica, alumina, zirconium oxide, titanium oxide and magnesium
oxide, with silica and alumina being particularly preferred. In
this connection, one of these materials or any combination of at
least two of them may be used and further a film of each material
may be laminated with that of a material identical to or different
from the former material.
[0081] The vapor deposition of such a thin film may be carried out
according to any known method, for example, a physical vapor
deposition technique (PVD technique) such as the vacuum deposition
technique, the sputtering technique, the ion plating technique or
the laser ablazion technique; or a chemical vapor deposition
technique (CVD technique) such as the plasma chemical vapor
deposition technique, the thermal chemical vapor deposition
technique or the optical chemical vapor deposition technique.
[0082] A material constituting the oxygen-barrier coating includes
resins having a high ability to form hydrogen bonds such as
polyvinyl alcohol, ethylene-vinyl alcohol copolymers,
poly(meth)acrylic acids, poly(allyl-amine), polyacrylamide and
polysaccharides, vinylidene chloride resins, and epoxy-amines. In
addition, it is also preferred to incorporate an inorganic compound
having a lamellar structure such as montmorillonite into these
materials.
[0083] Moreover, containers having an oxygen-absorbing barrier
layer which comprises the foregoing oxygen-barrier resin containing
the oxygen-absorbing resin and the oxygen-absorbing resin
composition incorporated into the same are preferred as the
oxygen-absorbing container of the present invention. In this case,
a separate oxygen barrier layer and a separate oxygen-absorbing
layer are not necessarily used, and therefore this would permit the
simplification of the layer structure of the oxygen-absorbing
container.
[0084] The oxygen-absorbing container may be produced by any
molding method known per se.
[0085] For example, extrusion molding operations can be carried out
using a number of extruders corresponding to the kinds of the
resins used and a multilayered and multiple die to thus form a
multi-layer film, a multi-layer sheet, a multi-layer parison or a
multi-layer pipe. Alternatively, a multi-layer preform for molding
bottles may be prepared according to a co-injection molding
technique such as the simultaneous injection method or the
sequential injection method using a number of extruders
corresponding to the kinds of the resins used. Such a multi-layer
film, parison or preform can be further processed to thus form an
oxygen-absorbing multilayered container.
[0086] The packaging material such as a film may be used as pouches
having a variety of shapes, and a capping material for trays and
cups. Examples of such pouches include three sided seal or four
sided seal flat pouches, gusseted pouches, standing pouches and
pillow-shaped packaging bags. These bags may be prepared by any
known bag-manufacturing method. Moreover, a film or a sheet can be
subjected to a molding means such as the vacuum forming technique,
the pressure forming technique, the stretch forming technique and
the plug-assist forming technique to thus obtain a packaging
container having a cup-like or tray-like shape.
[0087] A multi-layer film or a multi-layer sheet may be prepared
using, for instance, the extrusion coating technique or the
sandwich-lamination technique. In addition, single-layer and
multi-layer films, which have been formed in advance, can be
laminated together by the dry-lamination technique. Such methods
specifically include, for example, a method in which a transparent
vapor deposited film can be laminated with a co-extruded film
having a three-layer structure--a thermoplastic resin layer/an
oxygen-absorbing layer/a thermoplastic resin (sealant)
layer--through the dry-lamination technique; a method in which two
layers--an oxygen-absorbing layer/a sealant layer--can be
extrusion-coated, through an anchoring agent, with a two-layer film
comprising biaxially oriented PET film/aluminum foil laminated
together by the dry-lamination technique; or a method in which a
polyethylene single-layer film is sandwich-laminated, through a
polyethylene-based oxygen-absorbing resin composition, with a
two-layer film comprising barrier coating film/polyethylene film
which are laminated by the dry-lamination technique, but the
present invention is not restricted to these specific methods at
all.
[0088] Furthermore, a bottle or a tube may easily be formed by
pinching off a parison, a pipe or a preform by using a pair of
split molds and then blowing a fluid through the interior thereof.
Moreover, a pipe or a preform is cooled, then heated to an
orientation temperature and oriented in the axial direction while
blow-orientating the same in the circumferential direction by the
action of a fluid pressure to thus form a stretch blow-molded
bottle.
[0089] The oxygen-absorbing container of the present invention can
effectively inhibit any penetration of external oxygen into the
container through the wall thereof and can absorb the oxygen
remaining in the container. For this reason, the container is quite
useful since it permits the maintenance of the internal oxygen
concentration at a quite low level over a long period of time, the
prevention of any quality deterioration of the content thereof due
to the action of oxygen present therein and the prolonging of the
shelf life of the content.
[0090] The oxygen-absorbing resin or composition of the present
invention can thus be used for the packaging of contents quite
susceptible to deterioration in the presence of oxygen, in
particular, foods such as coffee beans, tea leaves (green tea),
snacks, baked confectionery prepared from rice, Japanese unbaked
and semi-baked cakes, fruits, nuts, vegetables, fish and meat
products, pasted products, dried fish and meat, smoked fish and
meat, foods boiled in soy sauce, uncooked and cooked rice products,
infant foods, jam, mayonnaise, ketchup, edible fats and oils,
dressings, sauces and dairy products; beverages such as beer, wine,
fruit juices, green tea, and coffee; and other products such as
pharmaceutical preparations, cosmetic products and electronic
parts, but the present invention is not restricted to these
specific ones at all.
EXAMPLES
[0091] The present invention will hereunder be described in more
detail with reference to the following Examples. In the following
Examples, each numerical value was determined according to the
method specified below:
(1) Number Average Molecular Weight (Mn) and Molecular Weight
distribution (Mw/Mn)
[0092] This was determined by the gel permeation chromatography
(GPC) technique (HLC-8120 Model GPC available from Tosoh
Corporation) and expressed in terms of the value relative to that
of the polystyrene. In this case, chloroform was used as the
solvent.
(2) Relative Proportions of the Monomer Units in the Copolyester
Resin
[0093] Using a nuclear magnetic resonance spectroscopy
(.sup.1H-NMR, EX270 available from JEOL DATUM LTD.), relative
proportions of the acid components contained in the resin were
calculated. The relative proportions of the acid components were
calculated from area ratio of signals of proton of benzene ring
from terephthalic acid (8.1 ppm), proton of benzene ring from
isophthalic acid (8.7 ppm), methylene proton adjacent to ester
groups from terephthalic acid and isophthalic acid (4.3-4.4 ppm),
methylene proton adjacent to ester groups from
methyltetrahydrophthalic anhydride, succinic acid and adipic acid
(4.1-4.2 ppm), methylene proton from succinic acid (2.6 ppm) and
methylene proton from adipic acid (2.3 ppm). The solvent used
herein was deuterochloroform containing tetramethylsilane as a
reference material.
[0094] In this connection, it was confirmed that the relative
proportions in the copolyester resins were substantially identical
to the amounts (mole ratio) of monomers used in the
polymerization.
(3) Glass Transition Point (Tg)
[0095] This was determined in a nitrogen gas stream at a rate of
temperature rise of 10.degree. C./min using a differential scanning
calorimeter (DSC6220 available from Seiko Instruments Inc.).
(4) Handling Ability
[0096] The presence of blocking by resin sticking to a hopper was
evaluated as follows. The resin was cut into about 5 mm dice and
the resulting dice was placed in a vacuum drier at 50.degree. C.
for about 8 hours to crystallize it. If a blocking of the resulting
crystallized pellet occurred in a hopper of an extruder, said
evaluation was x; if a blocking of the resulting crystallized
pellet did not occur in a hopper of an extruder, said evaluation
was .smallcircle.; and if a blocking of the resulting crystallized
pellet occurred slightly in a hopper of an extruder, said
evaluation was .DELTA.
(5) Amount of Oxygen Absorbed
[0097] A specimen cut out was introduced into an oxygen-impermeable
steel foil-laminated cup having an inner volume of 85 cm.sup.3,
then the cup was heat sealed with an aluminum foil-laminated film
cap and stored within an atmosphere maintained at 22.degree. C.
After storage of the cup for a predetermined time period, the
oxygen gas concentration within the cup was determined by a
micro-gas chromatograph (M-200 available from Agirent Technology
Co., Ltd.) to thus calculate the amount of oxygen absorbed per 1
cm.sup.2 of the resin.
(6) Amount of Volatile Decomposition Products
[0098] A specimen cut out was encapsulated in a vial for headspace
gas chromatography having an inner volume of 22 cm.sup.3, and then
the vial was stored within an atmosphere maintained at 22.degree.
C. After storage of the vial for a predetermined time period, the
amount of volatile decomposition products within the vial was
determined by a gas chromatography equipment (6890 series available
from Agirent Technology Co., Ltd., column HP-5) equipped with
headspace sampler (HP7694 available from Hewlett Packard Co.) to
thus calculate the amount of volatile decomposition products per 1
ml of the absorbed oxygen.
Example 1
[0099] To a 300 ml volume separable flask equipped with a stirring
machine, a nitrogen gas-introduction tube and a Dean-Stark type
water separator, were added 66.5 g of methyl tetrahydro-phthalic
anhydride (available from Hitachi Chemical Co., Ltd.; HN-2200)
containing about 45% by mass of
4-methyl-.DELTA..sup.3-tetrahydrophthalic anhydride as monomer (A),
99.7 g of terephthalic acid (available from Wako Pure Chemical
Industries, Ltd.) as monomer (B), 180.2 g of 1,4-butanediol
(available from Wako Pure Chemical Industries, Ltd.) as monomer
(C), 0.103 g of isopropyl titanate (available from Kishida Chemical
Co., Ltd.) and 20 ml of toluene, and the reaction of these
components was continued at a temperature ranging from 150 to
200.degree. C. in a nitrogen gas atmosphere over about 6 hours,
while removing the water generated. Subsequently, the toluene was
removed from the reaction system, and finally the polymerization
was carried out under a reduced pressure of 0.1 kPa at 200.degree.
C. for about 6 hours to obtain rubber-like polyester E having
11.9.degree. C. of Tg. Mn and Mw/Mn of polyester E were about 8,600
and 6.5, respectively.
[0100] The resulting polyester E was formed into a sheet having an
average thickness of about 270 .mu.m using a hot press maintained
at 200.degree. C., and then a specimen of 20 cm.sup.2 was cut off
from the sheet and used for the evaluation of the amount of
absorbed oxygen. The results thus obtained are summarized in Table
1.
Example 2
[0101] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester F having 10.0.degree. C. of Tg.
monomer (A): HN-2200 83.1; monomer (B): TPA 83.1 g; and monomer
(C): BG 180.2 g.
[0102] Mn and Mw/Mn of the resulting polyester F were about 8,800
and 9.3, respectively.
[0103] The resulting polyester F was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 3
[0104] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester G having 9.3.degree. C. of Tg.
monomer (A): HN-2200 99.7 g; monomer (B): TPA 66.5 g; and monomer
(C): BG 180.2 g.
[0105] Mn and Mw/Mn of the resulting polyester G were about 6,000
and 7.7, respectively.
[0106] The resulting polyester G was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 4
[0107] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester H having 10.4.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 74.8 g and
isophthalic acid (available from Wako Pure Chemical Industries,
Ltd.; IPA) 8.3 g; and monomer (C): BG 180.2 g.
[0108] Mn and Mw/Mn of the resulting polyester H were about 8,200
and 9.5, respectively.
[0109] The resulting polyester H was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 5
[0110] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester I having 9.9.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 66.5 g and
isophthalic acid (available from Wako Pure Chemical Industries,
Ltd.; IPA) 16.6 g; and monomer (C): BG 180.2 g.
[0111] Mn and Mw/Mn of the resulting polyester I were about 7,900
and 10.3, respectively.
[0112] The resulting polyester I was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 6
[0113] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester J having 13.0.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 83.1 g; and monomer
(C): BG 126.2 g and ethylene glycol (available from Kishida
Chemical Co., Ltd.; EG) 37.2 g.
[0114] Mn and Mw/Mn of the resulting polyester J were about 6,400
and 7.5, respectively.
[0115] The resulting polyester J was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 7
[0116] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester K having 7.0.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 83.1 g; and monomer
(C): BG 162.2 g and 1,6-hexanediol (available from Wako Pure
Chemical Industries, Ltd.; HG) 23.6 g.
[0117] Mn and Mw/Mn of the resulting polyester K were about 7,800
and 8.9, respectively.
[0118] The resulting polyester K was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 8
[0119] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester L having 4.1.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 83.1 g; and monomer
(C): BG 144.2 g and HG 47.3 g.
[0120] Mn and Mw/Mn of the resulting polyester K were about 7,800
and 8.9, respectively.
[0121] The resulting polyester K was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus, obtained are summarized in Table 1.
Example 9
[0122] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester M having 6.6.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 74.8 g; monomer (C):
BG 180.2 g; and monomer (D): succinic acid (available from Wako
Pure Chemical Industries, Ltd.; SA) 5.9 g.
[0123] Mn and Mw/Mn of the resulting polyester M were about 7,700
and 13.2, respectively.
[0124] The resulting polyester M was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 10
[0125] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester N having 2.7.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 66.5 g; monomer (C):
BG 180.2 g; and monomer (D): SA 11.8 g.
[0126] Mn and Mw/Mn of the resulting polyester N were about 8,000
and 13.3, respectively.
[0127] The resulting polyester N was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 11
[0128] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester O having 3.3.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 74.8 g; monomer (C):
BG 180.2 g; and monomer (D): adipic acid (available from Wako Pure
Chemical Industries, Ltd.; AA) 7.3 g.
[0129] Mn and Mw/Mn of the resulting polyester O were about 7,300
and 8.9, respectively.
[0130] The resulting polyester O was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 12
[0131] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester P having 2.0.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 70.6 g; monomer (C):
BG 180.2 g; and monomer (D): AA 11.0 g.
[0132] Mn and Mw/Mn of the resulting polyester P were about 7,300
and 13.6, respectively.
[0133] The resulting polyester P was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 13
[0134] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester Q having -0.3.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 66.5 g; monomer (C):
BG 180.2 g; and monomer (D): AA 14.6 g.
[0135] Mn and Mw/Mn of the resulting polyester Q were about 7,500
and 13.5, respectively.
[0136] The resulting polyester Q was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 14
[0137] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester R having -6.1.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 58.1 g; monomer (C):
BG 180.2 g; and monomer (D): AA 21.9 g.
[0138] Mn and Mw/Mn of the resulting polyester R were about 6,800
and 10.2, respectively.
[0139] The resulting polyester R was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 15
[0140] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester S having 2.9.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 74.8 g; monomer (C):
BG 171.2 g and HG 11.8 g; and monomer (D): AA 7.3 g.
[0141] Mn and Mw/Mn of the resulting polyester S were about 7,300
and 11.7, respectively.
[0142] The resulting polyester S was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 16
[0143] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester T having 1.6.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 74.8 g; monomer (C):
BG 162.2 g and HG 23.6 g; and monomer (D): AA 7.3 g.
[0144] Mn and Mw/Mn of the resulting polyester T were about 8,000
and 10.4, respectively.
[0145] The resulting polyester T was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 17
[0146] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester U having -1.9.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 66.5 g; monomer (C):
BG 171.2 g and HG 11.8 g; and monomer (D): AA 14.6 g.
[0147] Mn and Mw/Mn of the resulting polyester U were about 8,100
and 12.6, respectively.
[0148] The resulting polyester U was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Example 18
[0149] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester V having -2.3.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (B): TPA 66.5 g; monomer (C):
BG 162.2 g and HG 23.6 g; and monomer (D): AA 14.6 g.
[0150] Mn and Mw/Mn of the resulting polyester V were about 8,000
and 15.1, respectively.
[0151] The resulting polyester V was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Comparative Example 1
[0152] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester W having 2.0.degree. C. of Tg.
monomer (A): HN-2200 166.2 g; and monomer (C): BG 180.2 g.
[0153] Mn of the resulting polyester W was about 5,200 while Mw/Mn
of polyester W''was 27 which are very large. In addition, the resin
contained a small amount of gel.
[0154] Although the resulting polyester W was treated in a vacuum
dryer at 50.degree. C. for about 8 hours, the appearance thereof
was not especially changed and also the polyester W was not
crystallized. In addition, polyester W has a sticky surface and
thus has a poor handling ability because of a tendency to block.
Although polyester W was tried to form a sheet using a hot press,
it could not be done.
Comparative Example 2
[0155] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester X having -22.3.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (C): BG 180.2 g; and monomer
(D): SA 59.1 g.
[0156] Mn and Mw/Mn of the resulting polyester X were about 4,800
and 10.1, respectively.
[0157] The resulting polyester X was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
Comparative Example 3
[0158] The same polymerization as that of Example 1 was repeated,
except that the following composition of monomers was used, to
obtain rubber-like polyester Y having -35.5.degree. C. of Tg.
monomer (A): HN-2200 83.1 g; monomer (C): BG 180.2 g; and monomer
(D): AA 73.1 g.
[0159] Mn and Mw/Mn of the resulting polyester Y were about 5,300
and 34.8, respectively.
[0160] The resulting polyester Y was used for the evaluation of the
amount of absorbed oxygen using the same way as that of Example 1.
The results thus obtained are summarized in Table 1.
TABLE-US-00001 TABLE 1 Oxygen- Relative proportions of monomers
(mol %) absorbing B C D Example resin A TPA IPA EG BG HG CHDM AA SA
1 E 18 60 -- -- 100 -- -- -- -- 2 F 23 50 -- -- 100 -- -- -- -- 3 G
27 40 -- -- -- -- -- -- -- 4 H 23 45 5 -- 100 -- -- -- -- 5 I 23 40
10 -- 100 -- -- -- -- 6 J 23 50 -- 30 70 -- -- -- -- 7 K 23 50 --
-- 90 10 -- -- -- 8 L 23 50 -- -- 80 20 -- -- -- 9 M 23 45 -- --
100 -- -- -- 5 10 N 23 40 -- -- 100 -- -- -- 10 11 0 23 45 -- --
100 -- -- 5 -- 12 P 23 42.5 -- -- 100 -- -- 7.5 -- 13 Q 23 40 -- --
100 -- -- 10 -- 14 R 23 35 -- -- 100 -- -- 15 -- 15 S 23 45 -- --
95 5 -- 5 -- 16 T 23 45 -- -- 90 10 -- 5 -- 17 U 23 40 -- -- 95 5
-- 10 -- 18 V 23 40 -- -- 90 10 -- 10 -- *1 W 45 -- -- -- -- 100 --
-- -- *2 X 23 -- -- -- 100 -- -- -- 50 *3 Y 23 -- -- -- 100 -- --
50 -- Amount of oxygen Absorbed Tg Handling (ml/cm.sup.2) Overall
(.degree. C.) ability After 3 days After 14 days judgment 1 11.9
.largecircle. 0.031 0.116 .largecircle. 2 10.0 .largecircle. 0.052
0.176 .largecircle. 3 9.3 .largecircle. 0.061 0.190 .largecircle. 4
10.4 .largecircle. 0.055 0.228 .largecircle. 5 9.9 .largecircle.
0.054 0.223 .largecircle. 6 13.0 .largecircle. 0.036 0.139
.largecircle. 7 7.0 .largecircle. 0.075 0.200 .largecircle. 8 4.1
.DELTA. 0.087 0.280 .largecircle. 9 6.6 .largecircle. 0.070 0.208
.largecircle. 10 2.7 .DELTA. 0.082 0.230 .largecircle. 11 3.3
.largecircle. 0.065 0.214 .largecircle. 12 2.0 .largecircle. 0.100
0.254 .circleincircle. 13 -0.3 .DELTA. 0.090 0.271 .largecircle. 14
-6.1 .DELTA. 0.045 0.312 .largecircle. 15 2.9 .largecircle. 0.083
0.232 .largecircle. 16 1.6 .largecircle. 0.088 0.253 .largecircle.
17 -1.9 .DELTA. 0.090 0.279 .largecircle. 18 -2.3 .DELTA. 0.077
0.281 .largecircle. *1 2.0 X A sheet could A sheet could X not be
formed. not be formed. *2 -22.3 X 0.001 0.087 X *3 -35.5 X 0.005
0.326 X *Comparative Example
Example 19
[0161] Oxygen-absorbing resin F (50 parts by mass) and
metallocene-catalyzed linear low-density polyethylene (m-LLDPE,
EVOLUE SP0511 available from Prime Polymer Co., Ltd., 50 parts by
mass) as a thermoplastic resin were melt-blended, in a laboratory
mixing extruder (CS-194AV available from Toyo Seiki Co., Ltd.) at a
temperature of 200.degree. C. to obtain resin composition 1.
[0162] The resulting resin composition 1 was formed into a sheet
having an average thickness of about 270 .mu.m using a hot press
maintained at 200.degree. C., and specimens of 20 cm.sup.2 and 5
cm.sup.2 were cut off from the sheet and used for the evaluations
of the amount of absorbed oxygen and volatile decomposition
products. The results thus obtained are summarized in Table 2.
Example 20
[0163] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin F (50 parts by mass) and low-density
polyethylene (LDPE Sumikathene L-705 available from Sumitomo
Chemical Co., Ltd., 50 parts by mass) as a thermoplastic resin were
used, to obtain resin composition 2.
[0164] The resulting resin composition 2 was used for the
evaluation using the same way as that of Example 19. The results
thus obtained are summarized in Table 2.
Example 21
[0165] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin H (50 parts by mass) and m-LLDPE
(EVOLUE SP0511, 50 parts by mass) as a thermoplastic resin were
used, to obtain resin composition 3.
[0166] The resulting resin composition 3 was used for the
evaluation using the same way as that of Example 19. The results
thus obtained are summarized in Table 2.
Example 22
[0167] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin H (50 parts by mass) and LDPE
(Sumikathene L-705, 50 parts by mass) as a thermoplastic resin were
used, to obtain resin composition 4.
[0168] The resulting resin composition 4 was used for the
evaluation using the same way as that of Example 19. The results
thus obtained are summarized in Table 2.
Example 23
[0169] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin H (50 parts by mass) and polybutylene
terephthalate copolymer (PBT, DURANEX 600LP available from
Polyplastics Co., Ltd., 50 parts by mass) as a thermoplastic resin
were used, to obtain resin composition 5.
[0170] The resulting resin composition 5 was used for the
evaluation using the same way as that of Example 19. The results
thus obtained are summarized in Table 2.
Example 24
[0171] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin H (50 parts by mass) and polybutylene
succinate (PBS, GS-pla AZ91T available from Mitsubishi Chemical
Corporation, 50 parts by mass) as a thermoplastic resin were used,
to obtain resin composition 6.
[0172] The resulting resin composition 6 was used for the
evaluation using the same way as that of Example 19. The results
thus obtained are summarized in Table 2.
Example 25
[0173] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin. F (50 parts by mass) and
metallocene-catalyzed linear low-density polyethylene (m-LLDPE,
UMERIT 140HK available from UBE-MARUZEN POLYETHYLENE Co., Ltd., 50
parts by mass) as a thermoplastic resin were used, to obtain resin
composition 7.
[0174] The resulting resin composition 7 was formed into a film
having an average thickness of about 60 .mu.m using a hot press
maintained at 200.degree. C., and specimen of 20 cm.sup.2 was cut
off from the film and used for the evaluation of the amount of
absorbed oxygen. The results thus obtained are summarized in Table
2.
Example 26
[0175] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin F (50 parts by mass) and
metallocene-catalyzed low-density polyethylene (m-LDPE, EXCELLEN
GMH CB5002 available from SUMITOMO CHEMICAL Co., Ltd., 50 parts by
mass) as a thermoplastic resin were used, to obtain resin
composition 8.
[0176] The resulting resin composition 8 was used for the
evaluation using the same way as that of Example 25. The results
thus obtained are summarized in Table 2.
Example 27
[0177] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin P (50 parts by mass) and m-LLDPE
(UMERIT 140HK, 50 parts by mass) as a thermoplastic resin were
used, to obtain resin composition 9.
[0178] The resulting resin composition 9 was used for the
evaluation using the same way as that of Example 25. The results
thus obtained are summarized in Table 2.
Example 28
[0179] The same process as that of Example 19 was repeated, except
that oxygen-absorbing resin P (30 parts by mass) and m-LLDPE
(UMERIT 140HK, 70 parts by mass) as a thermoplastic resin were
used, to obtain resin composition 10.
[0180] The resulting resin composition 10 was used for the
evaluation using the same way as that of Example 25. The results
thus obtained are summarized in Table 2.
Example 29
[0181] Oxygen-absorbing resin F (50 parts by mass), low-density
polyethylene (LDPE, L-719 available from UBE-MARUZEN POLYETHYLENE
Co., Ltd., 50 parts by mass) as a thermoplastic resin and acetyl
tributyl citrate (ATBC, available from ASAHI KASEI FINECHEM CO.,
LTD., 2.5 parts by mass) as a plasticizer were melt-blended, in a
laboratory mixing extruder at a temperature of 200.degree. C. to
obtain resin composition 11. Resin composition 11 had 4.6.degree.
C. of Tg from the oxygen-absorbing resin.
[0182] The resulting resin composition 11 was used for the
evaluation using the same way as that of Example 25. The results
thus obtained are summarized in Table 2.
TABLE-US-00002 TABLE 2 Amount of Oxygen- Oxygen- absorbing
Thermoplastic absorbing Thickness Example resin resin Plasticizer
resin (wt %) (.mu.m) 19 F m-LLDPE -- 50 270 20 F LDPE -- 50 270 21
H m-LLDPE -- 50 270 22 H LDPE -- 50 270 23 H PBT -- 50 270 24 H PBS
-- 50 270 25 F m-LLDPE -- 50 60 26 F m-LDPE -- 50 60 27 P m-LLDPE
-- 50 60 28 P m-LLDPE -- 30 60 29 F LDPE ATBC 49 60 Amount of
oxygen Absorbed Amount of volatile (ml/cm.sup.2) decomposition
After 3 After 7 After 14 products Overall Example days days days
(pA*s/ml/14 days) judgment 19 -- -- 0.208 120.8 .circleincircle. 20
-- -- 0.203 203.5 .largecircle. 21 -- -- 0.216 92.4
.circleincircle. 22 -- -- 0.219 231.2 .largecircle. 23 -- -- 0.064
542 .largecircle. 24 -- -- 0.076 252.3 .largecircle. 25 0.022 0.054
0.076 -- .largecircle. 26 0.012 0.036 0.062 -- .largecircle. 27
0.070 0.119 0.151 -- .circleincircle. 28 0.037 0.074 0.098 --
.largecircle. 29 0.065 0.120 0.161 -- .circleincircle.
Example 30
[0183] 1 kg of resin F was prepared and then dried under vacuum of
0.1 kPa or less at 50.degree. C. for 8 hours to crystallize it. The
resulting crystals (50 parts by mass) were ground and then T die
method was applied to the ground product by using LABO PLASTOMILL
(Toyo Seiki Seisaku-sho, LTD.) at a forming temperature of
200.degree. C. to form a film. Finally, a three-layer coextrusion
film (EMAA (15 .mu.m)/resin F (60 .mu.m)/EMAA (15 .mu.m), thickness
is shown in parentheses.) of said film and an ethylene methacrylic
acid resin (EMSS, Nucrel N1035 available from DU PONT-MITSUI
POLYCHEMICALS) was obtained.
[0184] In addition, A 12 .mu.m thick transparent, vapor deposited,
biaxially oriented polyethylene terephthalate (PET) film (GL-AEH
available from Toppan Printing Co., Ltd.) was adhered to a 30 .mu.m
thick LDPE film (V-1 available from Tama Poly Company) which was
previously corona-treated on one side using a two-pack type
urethane adhesive (TAKELACK A-315+TAKENATE A-50 available from
Takeda Chemical Industries, Ltd.) in such a manner that the
vapor-deposited surface of the vapor-deposited film faced the
corona-discharged surface of the LDPE film and then the adhesive
was cured at 50.degree. C. for 3 days to thus prepare a two-layer
film of transparent vapor-deposited PET/LDPE. The above three-layer
coextrusion film was thermally laminated with the resulting
two-layer film on the LDPE side of the resulting two-layer film to
form an oxygen absorbing laminate film.
[0185] The resulting laminate films were put on top of each other
so that the three-layer coextrusion films were opposed to one
another and the 4 sides thereof were heat-sealed to obtain a
transparent flat pouch having an effective area of 80 cm.sup.2 and
an inner volume of 15 ml. This flat pouch was stored at 22.degree.
C. and then the oxygen concentration within the pouch was monitored
using a micro-gas chromatograph (M200 available from Agilent
Technologies, Inc.). The results thus obtained are listed in the
Table 3.
Example 31
[0186] 1 kg of resin F was prepared and then dried under vacuum of
0.1 kPa or less at 50.degree. C. for 8 hours to crystallize it. The
resulting crystals (50 parts by mass) were ground, and then the
resulting ground product and m-LLDPE (UMERIT 140HK, 50 parts by
mass) as a thermoplastic resin were melt-blended at a blade
rotational number of 100 rpm and a forming temperature of
200.degree. C. while being evacuated to a high vacuum through a
vent using a twin-screw extruder (TEM-35B available from Toshiba
Machine Co., Ltd.) equipped with a strand die at the outlet portion
thereof to obtain resin composition 12. This resin composition had
a high melt viscosity and thus an excellent extrusion
moldability.
[0187] In addition, T die method was applied to the resin
composition 12 by using LABO PLASTOMILL (Toyo Seiki Seisaku-sho,
LTD.) at a forming temperature of 200.degree. C. to form a film,
and finally a three-layer coextrusion film (m-LLDPE (15
.mu.m)/resin composition 12 (60 .mu.m)/m-LLDPE (15 .mu.m),
thickness is shown in parentheses.) of said film and m-LLDPE was
obtained.
[0188] Like in Example 30, the two-layer film of transparent
vapor-deposited PET/LDPE was laminated with the resulting
coextrusion film to form a flat pouch and then the oxygen
concentration within the pouch was monitored. The results thus
obtained are listed in the Table 3.
Example 32
[0189] Like in Example 31, a flat pouch was formed and then the
oxygen concentration within the pouch was monitored except that 1
kg of resin H instead of resin F was prepared. The results thus
obtained are listed in the Table 3.
Example 33
[0190] Like Example 31, a flat pouch was formed and then the oxygen
concentration within the pouch was monitored except that 1 kg of
resin P instead of resin F was prepared. The results thus obtained
are listed in the Table 3.
Example 34
[0191] 1 kg of resin F was prepared and then dried under vacuum of
0.1 kPa or less at 50.degree. C. for 8 hours to crystallize it. The
resulting crystals (50 parts by mass) were ground, and then the
resulting ground product, LDPE (L719, 50 parts by mass) as a
thermoplastic resin and ATBC (2 parts by mass) as a plasticizer
were melt-blended at a blade rotational number of 100 rpm and a
forming temperature of 200.degree. C. while being evacuated to a
high vacuum through a vent using a twin-screw extruder (TEM-35B
available from Toshiba Machine Co., Ltd.) equipped with a strand
die at the outlet portion thereof to obtain resin composition 13.
This resin composition had a high melt viscosity and thus an
excellent extrusion moldability.
[0192] In addition, T die method was applied to the resin
composition 13 by using LABO PLASTOMILL at a forming temperature of
200.degree. C. to form a film, and finally a three-layer
coextrusion film (LDPE (15 .mu.m)/resin composition 13 (60
.mu.m)/LDPE (15 .mu.m), thickness is shown in parentheses.) of said
film and a LDPE resin was obtained.
[0193] Like in Example 30, the two-layer film of transparent
vapor-deposited PET/LDPE was laminated with the resulting
coextrusion film to form a flat pouch and then the oxygen
concentration within the pouch was monitored. The results thus
obtained are listed in the Table 3.
TABLE-US-00003 TABLE 3 Oxygen concentration within the pouch (%)
After 0 After 1 After 2 After 4 After 7 After 10 Example day day
days days days days 30 20.9 19.0 14.5 3.4 0.2 0 31 20.9 19.8 16.4
7.8 2.1 0.4 32 20.9 19.7 16.1 5.8 1.2 0.0 33 20.9 20.2 17.6 4.4 0.7
0.0 34 20.9 19.4 16.0 4.0 0.5 0.0
* * * * *