Olefin resin-based articles having gas barrier properties

An olefin resin-based article having gas barrier properties, comprising a crystalline olefin copolymer having an inorganic oxide thin film layer formed thereon where the crystalline olefin copolymer comprises ethylene or an .alpha.-olefin having from 3 to 12 carbon atoms and a diene and having a diene unit content of from 0.05 to 20 mol %, wherein the article suffers from no reduction in gas barrier properties even when heat or stress is applied during fabrication or use and is useful as a wrapping or packaging material for making pouch-packed foods or IC packages.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to olefin resin-based articles having 
excellent gas barrier properties which are useful in packaging 
applications, such as in the protection of foods and electronic 
components. 
2. Discussion of the Background 
Packaging foods, electronic components, and other oxygen sensitive entities 
in a film or a container which suppresses oxygen permeation has been 
proposed for protecting the package contents from oxidation, thereby 
maintaining the quality of the contents for prolonged periods of time. 
For example, JP-B-53-12953 (the term "JP-B" as used herein means an 
"examined published Japanese patent application") discloses a transparent 
flexible plastic film with low permeability to gases and moisture. This 
film comprises a flexible plastic film, such as polyethylene 
terephthalate, cellophane, nylon, polypropylene, or polyethylene, having a 
thickness of from 5 to 300 .mu.m and have a transparent thin layer of a 
silicon compound represented by the general formula Si.sub.x O.sub.y 
(wherein x is 1 or 2; and y is 0, 1, 2 or 3) formed on at least one side 
thereof to a thickness of from 100 to 3,000 .ANG.. 
JP-A-63-237940 (the term "JP-A" as used herein means an "unexamined 
published Japanese patent application") discloses a transparent film 
having gas barrier properties comprising the above-mentioned flexible 
plastic film and having a metal oxide layer comprising an oxide of at 
least one of the following elements In, Sn, Zn, Zr or Ti formed on at 
least one side thereof by sputtering. Additionally a transparent 
heat-sealable resin film is coated thereon. 
When a film material made of a polar resin, such as polyethylene 
terephthalate, nylon or cellophane, is used in the above process, 
sufficient adhesion to an inorganic oxide film and satisfactory gas 
barrier properties are obtained. 
However, when the above-mentioned inorganic oxide is deposited on the 
surface of a resin-based article comprising a non-polar resin, the 
inorganic oxide layer tends to become detached from the non-polar resin 
relatively easily, upon the application of external stress or heat to the 
molded article. This detachment is primarily due to inadequate adhesion 
between the non-polar resin-based article and the deposited inorganic 
oxide. This situation occurs particularly in cases where a heat sealable 
layer is laminated on the oxide-deposited non-polar resin molded article, 
when the article is used, when the laminated article (having a heat 
sealable layer) is fabricated into final form for bag making a cover 
sealing, when the container is filled, or when the container and contents 
are sterilized, such as in the production of pouch-packed foods. When 
detachment of the oxide layer occurs, the gas permeability increases and 
the practical utility of the article is severely decreased. 
Therefore, it is desirable to provide a resin-based article having good gas 
barrier properties, which does not undergo detachment of the inorganic 
oxide layer from the resin-based article and thus retains its gas barrier 
properties during fabrication and use. 
SUMMARY OF THE INVENTION 
Accordingly, one object of the present invention is to provide a 
resin-based article having good gas barrier properties comprising a 
polyolefin resin-based article and an inorganic oxide deposited thereon, 
wherein, the inorganic oxide deposit is prevented from detachment during 
fabrication or use, thereby retaining good gas barrier properties. 
A further object of the present invention is to provide an olefin 
resin-based article with improved gas barrier properties comprised of a 
crystalline olefin copolymer having an inorganic oxide thin layer 
deposited thereon, and a further layer of a thermoplastic resin laminated 
or coated thereon. 
These and other objects of the present invention have been satisfied by the 
discovery of an olefin resin-based article having gas barrier properties 
comprising a crystalline olefin copolymer having formed thereon an 
inorganic oxide thin layer, wherein the crystalline olefin copolymer 
comprises repeat units obtained from ethylene or an .alpha.-olefin having 
from 3 to 12 carbon atoms and from 0.05 to 20 mol % of a diene. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates to an olefin resin-based article having good 
gas barrier properties comprising a crystalline olefin copolymer having 
formed thereon an inorganic metal oxide thin layer, wherein the 
crystalline olefin copolymer comprises repeat units obtained from ethylene 
or an .alpha.-olefin having 3 to 12 carbon atoms and from 0.05 to 20 mol % 
of a diene. 
The crystalline olefin copolymer having a crystallinity of at least 1%, 
preferably from 20 to 70% (as measured by X-ray means), which can be used 
as a base material is a copolymer comprising ethylene or an .alpha.-olefin 
having from 3 to 12 carbon atoms and a diene having from 4 to 20 carbon 
atoms and having a diene unit content of from 0.05 to 20 mol %, preferably 
from 1 to 10 mol %. 
The unsaturated copolymer should have a number average molecular weight, 
M.sub.N, of at least 3,000, preferably at least 5,000. The copolymer of 
the present invention has either a melting point or a glass transition 
temperature no lower than 40.degree. C., preferably between 80.degree. and 
187.degree. C., and more preferably between 120.degree. and 174.degree. C. 
One of the monomer components of the olefin copolymer is ethylene or an 
.alpha.-olefin having 3 to 12 carbon atoms, such as propylene, 1-butene, 
1-hexene, 3-methyl-1butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 
3,3-dimethyl-1butene, 4,4-dimethyl-1-pentene, 3-methyl-1-hexene, 
4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 5-methyl1-hexene, 
allylcyclopentane, allylcyclohexane, allylbenzene 3-cyclohexyl-1-butene, 
vinylcyclopropane, vinylcyclohexane, and 2-vinylbicyclo[2,2,1]heptane. 
Preferred monomers are ethylene, propylene, 1-butene, 1hexene, 
3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1pentene, and 
3-methyl1hexene, with ethylene, propylene, 1-butene, 4-methyl-1-pentene 
and 3-methyl-1-butene being most preferred. 
Ethylene and the .alpha.-olefins may be used either individually or in 
combination of two or more thereof. In particular, propylene or a 
combination of propylene with at least one other monomer from the group of 
ethylene, 1butene, 4-methyl-1-pentene, and 3-methyl-1-butene is preferred, 
with the total content of the monomers other than propylene being no more 
than 5 mol %. When the amount of the other comonomers exceeds 5 mol %, the 
resulting copolymer exhibits undesirable rubbery properties. When two or 
more .alpha.-olefins are incorporated into the copolymer of the present 
invention, the .alpha.-olefins may be distributed randomly or in blocks. 
The diene monomers which can be copolymerized with the above-mentioned 
olefin monomers include conjugated dienes, acyclic or cyclic 
non-conjugated dienes and mixtures thereof, each having from 4 to 20 
carbon atoms, preferably from 4 to 14 carbon atoms. 
Examples of conjugated dienes include 1,3-dienes, such as 1,3-butadiene, 
isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,4-hexadiene, 
2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, 
2,3-dimethyl-1,3-butadiene, 2,4-heptadiene, 3,4-dimethyl-1,3pentadiene, 
4-methyl-1,3-hexadiene, 5-methyl-1,3-hexadiene, 
2,4-dimethyl-1,3-pentadiene, 4-ethyl-1,3-hexadiene, 
7-methyl-3-methylene-1,6-octadiene (myrcene), 1,3-butadiene, 
4-phenyl-1,3-pentadiene, and 1,4-diphenyl-1,3butadiene; and 
dialkenylbenzenes, such as divinylbenzene, isopropenylstyrene, 
divinyltoluene, divinylnaphthalene, and 
1-phenyl-1-(4-vinylphenyl)ethylene. 
The acyclic non-conjugated dienes useful in the present invention may be 
any acyclic non-conjugated diene which is copolymerizable with the olefin 
component(s) of the copolymer. Suitable acyclic non-conjugated dienes 
include those represented by formula (I): 
##STR1## 
wherein n represents an integer of from 1 to 10; and R.sup.1, R.sup.2, and 
R.sup.3 each, independently, represents hydrogen or an alkyl group having 
from 1 to 8 carbon atoms 
Preferred acyclic non-conjugated dienes of formula (I) are those wherein n 
is 1 to 5; and R.sup.1, R.sup.2, and R.sup.3 are each, independently, 
hydrogen or an alkyl group having from 1 to 4 carbon atoms, provided that 
R.sup.1, R.sup.2, and R.sup.3 do no simultaneously represent hydrogen. 
More preferred acyclic non-conjugated dienes of formula (I) are those 
wherein n is 1 to 3 carbon atoms; and R.sup.1 and R.sup.3 are each, 
independently, hydrogen or an alkyl group having 1 to 3 carbon atoms, 
provided that R.sup.2 and R.sup.3 do not simultaneously represent 
hydrogen. 
Specific examples of such acyclic non-conjugated dienes include acyclic 
1,4-dienes, such as 2-methyl-1,4pentadiene, 4-methylidene-1-hexane, 
1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 
1,4-heptadiene, 4-ethyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 
4-methyl-1,4-heptadiene, 4-ethyl-1,4-heptadiene, 5-methyl-1,4-heptadiene, 
and 5-methyl-1,4-octadiene; acyclic 1,5-dienes, such as 1,5-heptadiene, 
1,5-octadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, and 
2-methyl-1,5-hexadiene; acyclic 1,6-dienes, such as 1,6-octadiene, 
6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 2-methyl-1,6-heptadiene, 
6-methylidene1octene, 6-ethyl-1,6-octadiene, 6,7-dimethyl-1,6-octadiene, 
1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, and 
7-methyl-1,6-decadiene; acyclic 1,7-dienes, such as 1,7nonadiene, 
7-methyl-1,7-nonadiene, 8-methyl-1,7-nonadiene, and 
2-methyl-1,7-octadiene; and acyclic 1,8-dienes, such as 
8-methyl-1,8-decadiene and 9-methyl-1,8-decadiene. 
Suitable cyclic non-conjugated dienes include alkenylnorbornenes, such as 
cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, and 
5-vinyl-2-norbornene; alkylidenenorbornenes, such as 
5-ethylidene-2-norbornene, 5-methylene-2-norbornene, and 
5-isopropylidene-2-norbornene; and alkenylcyclohexenes, such as 
6-chloro-methyl-5-isopropenyl-2-norbornene, norbornadiene, and 
4-vinylcyclohexene. 
Preferred dienes for use in the copolymer of the present invention are 
acyclic non-conjugated dienes and dialkenylbenzenes, with 
4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 6-methyl-1,6-octadiene, 
7-methyl-l,6-octadiene, 1,9-octadiene, 1,13-tetradecadiene, 
isopropenylstyrene, and divinylbenzene being most preferred. When the 
article of the present invention is to be used as a packaging film for 
pouch-packed foods, 1,9-octadiene and 1,13-tetradecadiene are preferred 
because of their superior thermal stability characteristics. 
The diene monomers may be incorporated into the copolymer of the present 
invention either individually or in combinations of two or more thereof. 
For example, a combination of 4-methyl-1,4-hexadiene and 
5-methyl-1,4-hexadiene in a weight ratio of from 95:5 to 5:95 may be 
suitably used. Commercially available crude divinylbenzene, which is 
actually an isomeric mixture of m-divinylbenzene, p-divinylbenzene, 
ethylvinylbenzene, diethylbenzene, and other impurities, may be utilized 
without purification. 
The crystalline olefin copolymer can be prepared by copolymerizing ethylene 
or an .alpha.-olefin and a diene in the presence of a conventional 
Ziegler-Natta catalyst used in .alpha.-olefin polymerization. 
Additionally, conventional olefin polymerization techniques and apparatus 
can be used to prepare the copolymers of the present invention. 
The diene compound may be distributed in the olefin copolymer resin either 
at random or in blocks. 
The concentration of the repeating unit obtained from the diene monomer 
(herein referred to as diene unit content) in the olefin copolymer resin 
ranges from 0.05 to 20 mol %, preferably from 0.5 to 15 mol %, and more 
preferably from 1 to 10 mol %. When the diene unit content is less than 
0.05 mol %, the unreacted double bond content of the crystalline olefin 
copolymer resin is insufficient to obtain adequate adhesion to a deposited 
inorganic oxide layer. If the unreacted double bond content exceeds 20 mol 
%, the resulting crystalline olefin copolymer has reduced bending strength 
and reduced transparency. 
The number average molecular weight of the crystalline olefin copolymer 
must be sufficient to maintain a resinous state as previously described. 
For example, the molecular weight of a copolymer comprising predominantly 
propylene as an .alpha.-olefin sufficient to maintain a resinous state, 
corresponds to a melt flow rate (MFR) of from 0.01 to 100 g/10 min, and 
preferably from 0.02 to 50 g/10 min, as measured in accordance with JIS K 
6758 (230.degree. C., 2.16 kg load). Such an olefin copolymer resin has a 
modulus of elasticity of from 800 to 45,000 kg/cm.sup.2, and preferably 
from 1,000 to 35;000 kg/cm.sup.2, as measured in accordance with JIS K 
7203. 
The preferred types of olefin copolymer resin are divided, on the basis of 
molecular structure, into (1) random copolymers comprising repeat units 
obtained from one or more monomers selected from ethylene and the 
.alpha.-olefins and one or more dienes, (2) block copolymers comprising 
polymer blocks of repeat units obtained from one or more monomers selected 
from ethylene and the .alpha.-olefins and random copolymer blocks 
comprising repeat units obtained from one or more monomers selected from 
ethylene and the .alpha.-olefins and one or more dienes (the monomer 
identities of the ethylene or .alpha.-olefins in the ethylene or 
.alpha.-olefin polymer blocks and their proportions may be the same as or 
different from those of the ethylene or .alpha.-olefins in the random 
copolymer blocks), and (3) block copolymers comprising random copolymer 
blocks comprising repeat units obtained from one or more monomers selected 
from ethylene and the .alpha.-olefins and one or more dienes (hereafter 
referred to as block a) and random copolymer blocks comprising repeat 
units obtained from one or more monomers selected from ethylene and the 
.alpha.-olefins and one or more dienes (hereinafter referred to as block 
b), blocks a and b differing in at least one of the monomer identities, 
number of monomers, and proportions of monomers of the ethylene or 
.alpha.-olefins and the monomer identities, number of monomers, and 
proportions of monomers of the dienes. 
The terminology "block copolymer" as used herein has the following 
meanings: 
(1) A "block copolymer comprising homopolymer blocks of monomer A and 
random copolymer blocks of monomer A and monomer B" includes not only a 
block copolymer built up through chemical bonding of homopolymer blocks of 
monomer A and random copolymer blocks of monomers A and B to form a 
structure of A. . . AAABABAAAAB . . . but a blend of polymers containing 
(i) a copolymer built up through chemical bonding of homopolymer blocks of 
monomer A and random copolymer blocks of monomers A and B and (ii) a 
homopolymer of monomer A or (iii) a random copolymer of monomers A and B 
or a combination of (ii) and (iii). 
(2) A "block copolymer comprising polymer blocks a and b" includes not only 
polymers with blocks a and b chemically bonded to each other but a polymer 
blend containing (i) a block copolymer comprising chemically bound polymer 
blocks a and b, and (ii) a polymer solely comprising polymer blocks a 
and/or (iii) a polymer solely comprising polymer blocks b. 
Therefore the terminology "block copolymer" has the same general meaning as 
when referring to polymers synthesized with a Ziegler-Natta catalyst. 
Specific and preferred examples of the crystalline olefin copolymer include 
(1) a propylene/4-methyl-1,4hexadiene/5-methyl-1,4-hexadiene random 
copolymer, (2) a block copolymer comprising propylene homopolymer blocks 
and ethylene/4-methyl-1,4-hexadiene/5-methyl-1,4,hexadiene random 
copolymer blocks, (3) an 
ethylene/4-methyl-1,4-hexadiene/5-methyl-1,4-hexadiene random copolymer, 
(4) a propylene/ethylene/4-methyl-1,4-hexadiene/5-methyl-1,4-hexadiene 
random copolymer, (5) a block copolymer comprising 
ethylene/4-methyl-1,4-hexadiene/5-methyl-1,4-hexadiene random copolymer 
blocks and propylene/4-methyl-1,4-hexadiene/5-methyl-1,4-hexadiene random 
copolymer blocks, (6) a propylene/7-methyl-1,6-octadiene random copolymer, 
(7) a block copolymer comprising propylene homopolymer blocks and 
ethylene/propylene/7-methyl-1,6-octadiene random copolymer blocks, (8) a 
block copolymer comprising propylene homopolymer blocks and 
propylene/7-methyl-1,6-octadiene random copolymer blocks, (9) an 
ethylene/propylene/7-methyl-1,6-octadiene random copolymer, (10) a block 
copolymer comprising ethylene/propylene random copolymer blocks and 
propylene/7-methyl1,6-octadiene random copolymer blocks, (11) a block 
copolymer comprising ethylene/propylene random copolymer blocks and 
ethylene/propylene/7-methyl-1,6-octadiene random copolymer blocks, (12) a 
3-methyl1butene/7-methyl-1,6-octadiene random copolymer, (13) a 
propylene/divinylbenzene random copolymer, (14) an ethylene/divinylbenzene 
random copolymer, (15) a propylene/ethylene/divinylbenzene random 
copolymer, (16) a block copolymer comprising propylene homopolymer blocks 
and ethylene/divinylbenzene random copolymer blocks, (17) a block 
copolymer comprising propylene homopolymer blocks and 
propylene/ethylene/divinylbenzene random copolymer blocks, (18) a block 
copolymer comprising propylene/divinylbenzene random copolymer blocks and 
ethylene/divinylbenzene random copolymer blocks, (19) a block copolymer 
comprising propylene/divinylbenzene random copolymer blocks and 
propylene/ethylene/divinylbenzene random copolymer blocks, and (20) a 
3-methyl-1-butene/divinylbenzene random copolymer. 
The crystalline olefin copolymer of the present invention may be diluted 
with polypropylene, polyethylene, a propylene/ethylene copolymer, an 
ethylene/butene-1 copolymer, an ethylene/octene-1 copolymer, an ethylene/ 
hexane-1 copolymer, a propylene/butene-1 copolymer, a 
propylene/ethylene/butene-1 copolymer, a propylene/4-methylpentene-1 
copolymer, or similar polymers. However, in diluting the copolymer the 
resultant resin mixture should contain from 1.times.10.sup.-4 to 
2.times.10.sup.-2 carbon-to-carbon double bonds per 100 g of the total 
resin content. 
Articles which can be formed from the crystalline olefin copolymer include 
films, sheets, containers, and cases. These articles may be obtained by 
conventional processes, such as extrusion, injection molding, vacuum 
forming, and blow molding. The molded articles may have a laminate 
structure composed of the crystalline olefin copolymer and a thermoplastic 
resin, such as polyethylene, polypropylene, an ethylene-vinyl acetate 
copolymer, polyamide, polybutylene terephthalate, polyethylene 
terephthalate, polyphenylene sulfide, polyphenylene ether, polycarbonate, 
polyvinylidene chloride, polyvinylidene fluoride, and polyethylvinyl 
alcohol. The films or sheets may be subjected to stretching. 
The films preferably have a thickness of from 5 to 200 .mu.m. The sheets 
preferably have a thickness of from 200 to 1,500 .mu.m. Small containers 
or cases preferably have a wall thickness of from 300 to 2,500 .mu.m. 
Tanks or 20 l-volume chemical storage vessels preferably have a wall 
thickness of from 1 to 10 mm. 
If desired, the molded articles may be subjected to an oxidation treatment, 
such as a corona discharge treatment, an ozone treatment, a glow discharge 
treatment, a plasma treatment, or a treatment with a chemical. However, 
since, in many cases, subsequent deposition of an inorganic oxide is 
usually accompanied by such an oxidation treatment, there is no particular 
need of such an oxidation treatment during or after molding. 
The inorganic oxide thin layer can be any metal oxide thin layer. Suitable 
oxides include deposits of SiO.sub.x, SnO.sub.x, ZnO.sub.x, or IrO.sub.x 
wherein x is a number from 1 to 2. The deposit thickness may be any 
thickness which provides sufficient transparency, deposition rate, gas 
barrier properties and take-up properties of the film, with thicknesses of 
from 200 to 4,000 .ANG. being preferred and from 300 to 3,000 .ANG. being 
more preferred. 
Deposition methods include a method in which an inorganic oxide is 
deposited on a molded article in vacuo (1.times.10.sup.-3 to 
1.times.10.sup.-6 Torr) in a vacuum deposition apparatus utilizing 
radiofrequency induction heating system (see JP-B-53-12953) and a method 
in which a gas stream containing an organosilicone compound, oxygen and an 
inert gas is generated in a vacuum deposition apparatus previously 
evacuated and a plasma is then generated in the gas stream by a magnetron 
glow discharge, depositing SiO.sub.x on a molded article in the vacuum 
deposition apparatus (see JP-A-64-87772 and U.S. Pat. Nos. 4,557,946 and 
4,599,678). Additionally, various deposition methods which may be used in 
the preparation of the article of the present invention are described in 
KOGYO ZAIRYO, Vol. 38, No. 14, pp. 104-105 (November, 1990) under the 
classifications of ion plating, high-frequency plasma CVD, electron beam 
(EB) deposition, and sputtering.

Having generally described this invention, a further understanding can be 
obtained by reference to certain specific examples which are provided 
herein for purposes of illustration only and are not intended to be 
limiting unless otherwise specified. All the percents are by weight unless 
otherwise specified. 
SYNTHESIS EXAMPLE 
Preparation of Catalyst-on-Carrier: 
In a flask thoroughly purged with nitrogen was put 100 ml of dehydrated and 
deoxidized n-heptane, and 0.1 mol of magnesium chloride and 0.20 mol of 
titanium tetrabutoxide were added thereto, followed by allowing the 
mixture to react at 100.degree. C. for 2 hours. The temperature was 
lowered to 40.degree. C., and 15 ml of methyl hydrogen polysiloxane was 
added thereto and reacted for 3 hours. After completion of the reaction, 
the solid component produced was washed with n-heptane. Composition 
analysis on an aliquot of the solid component revealed a Ti content of 
15.2% and an Mg content of 4.2%. 
In a flask thoroughly purged with nitrogen was charged 100 ml of dehydrated 
and deoxidized n-heptane, and 0.03 mol of the above-prepared solid 
component was added thereto. To the flask was further introduced 0.05 mol 
of silicon tetrachloride at 30.degree. C. over a period of 15 minutes, and 
the mixture was allowed to react at 90.degree. C. for 2 hours. After 
completion of the reaction, the reaction mixture was washed with purified 
n-heptane. A mixture of 25 ml of n-heptane and 0.004 mol of o-C.sub.6 
H.sub.4 (COCl).sub.2 was added to the reaction mixture at 50.degree. C. 
and 0.05 mol of silicon tetrachloride was then added thereto, followed by 
allowing the mixture to react at 90.degree. C. for 2 hours. After 
complexion of the reaction, the reaction mixture was washed with n-heptane 
to obtain a catalyst component having a Ti content of 2.05%. 
Preparation of Olefin Copolymer (1): 
In a 10 l autoclave thoroughly purged with propylene were charged 3.3 l of 
n-heptane, and 1.0 g of triethylaluminum, 0.44 g of 
diphenyldimethoxysilane, and 0.7 g of the above-prepared 
catalyst-on-carrier were added thereto in this order. To the autoclave was 
fed 800 ml of hydrogen, and propylene was then introduced under pressure 
to an inner pressure of 0.5 kg/cm.sup.2 G. The mixture was stirred at 
50.degree. C. at that pressure. Thereafter, 1200 ml of 1,4-hexadiene was 
added thereto, the temperature was elevated while introducing propylene 
under pressure to an inner pressure of 5.5 kg/ cm.sup.2 G, and the mixture 
was kept at 65.degree. C. under that pressure for 5 hours to conduct 
polymerization. The catalyst was inactivated with n-butanol, the residual 
catalyst was extracted with water, and the copolymer was recovered by 
centrifugation and dried to obtain 1940 g a dry powder having a bulk 
density of 0.50 g/cc and an amorphous polymer content of 54 g. The 
copolymer had an MFR (230.degree. C., 2.16 kg load; hereinafter the same) 
of 2 g/10 min, a density of 0.895 g/cm.sup.3, crystallinity of 37%, and a 
modulus of elasticity of 5,500 kg/cm.sup.2. The 1,4-hexadiene unit content 
was 3.3 mol % as analyzed by H.sup.1 -NMR, and had a 1,2-addition 
structure. 
Preparation of Olefin Copolymer (2): 
A random copolymer comprising 99.95 mol % of propylene and 0.05 mol % of 
1,4-hexadiene was prepared in the same manner as the olefin copolymer (1), 
except for changing the amount of 1,4-hexadiene. Olefin copolymer (2) had 
an MFR of 2 g/10 min, a density of 0.903 g/cm.sup.3, a crystallinity of 
60%, and a modulus of elasticity of 11,000 kg/cm.sup.2. 
Preparation of Olefin Copolymer (3): 
A random copolymer comprising 99.99 mol % of propylene and 0.01 mol % of 
1,4-hexadiene was prepared in the same manner as for olefin copolymer (1), 
except for changing the amount of 1,4-hexadiene. Olefin copolymer (3) had 
an MFR of 2 g/10 min, a density of 0.904 g/cm.sup.3, a crystallinity of 
67%, and a modulus of elasticity of 12,000 kg/cm.sup.2. 
Preparation of Olefin Copolymer (4): 
A random copolymer comprising 90.0 mol % of propylene and 10 mol % of 
1,4-hexadiene was prepared in the same manner as for olefin copolymer (1), 
except for changing the amount of 1,4-hexadiene. Olefin copolymer (4) had 
an MFR of 2 g/10 min, a density of 0.904 g/cm.sup.3 crystallinity of 21%, 
and a modulus of elasticity of 1,000 kg/cm.sup.2. 
Preparation of Olefin Copolymer (5): 
In a 10 l autoclave thoroughly purged with propylene were charged 3.3 l of 
n-heptane, and 1.0 g of triethylaluminum, 10.44 g of 
diphenyldimethoxysilane, and 0.7 g of the above-prepared 
catalyst-on-carrier were added thereto in this order. To the autoclave was 
fed 800 Nml of hydrogen, and propylene was then introduced under pressure 
to an inner pressure of 0.5 kg/cm.sup.2 G. The mixture was stirred at 
50.degree. C. at that pressure. Thereafter, 750 ml of 
7-methyl-1,6-octadiene was added to the reaction mixture, the temperature 
was elevated while introducing propylene under pressure to an inner 
pressure of 5.5 kg/cm.sup.2 G, and the mixture was kept at 65.degree. C. 
under that pressure for 5 hours to conduct polymerization. The catalyst 
was inactivated with n-butanol, the residual catalyst was extracted with 
water, and the copolymer produced was recovered by centrifugation and 
dried to obtain 1940 g a dry powder having a bulk density of 0.50 g/cc and 
an amorphous polymer content of 54 g. Copolymer (5) had an MFR of 1.4 g/10 
min, a crystallinity of 42%, and a modulus of elasticity of 8,100 
kg/cm.sup.2 and showed a melting peak at 149.degree. C. in DSC 
measurement. The 7-methyl-1,6-octadiene unit content was 2.7 mol % as 
analyzed by H.sup.1 -NMR, and had a 1,2-addition structure. 
EXAMPLE 1 
Olefin copolymer (1) (propylene content: 96.7 mol %; 1,4-hexadiene content: 
3.3 mol %) was melt-kneaded in an extruder at 230.degree. C. and extruded 
through a T-die at 220.degree. C. The extruded sheet was cooled on a 
metallic roll to obtain a 1 mm thick sheet. 
The sheet was heated to 120.degree. C. and stretched 5-fold in the 
longitudinal direction (or machine direction) by making use of a 
difference in the peripheral speed of rolls. 
The stretched film was then re-heated to 151.degree. C. in a tentering oven 
and 10-fold stretched in the cross (or transverse) direction using a 
tenter frame. The biaxially stretched film was subjected to annealing at 
167.degree. C. and then to a corona discharge treatment to obtain a 
biaxially stretched film having a thickness of 20 .mu.m (haze: 2.5%). 
The biaxially stretched film was placed in a plasma deposition apparatus. 
After evacuating the apparatus to 1.times.10.sup.-6 Torr, a mixed gas 
consisting of 35 parts by volume of hexamethyldisiloxane, 35 parts by 
volume of oxygen, 46 parts by volume of helium, and 35 parts by volume of 
argon was introduced into the apparatus and subjected to a glow discharge 
by a non-equilibrium magnetron to generate plasma. A SiO.sub.2 thin layer 
was thus deposited on the biaxially stretched film to a thickness of 1,000 
.ANG.. The discharge conditions were set so that the SiO.sub.2 -deposited 
film might have an oxygen permeability of 5.0 cc/m.sup.2.atm.day as 
measured in accordance with JIS 1707-75. 
COMATIVE EXAMPLE 1 
An SiO.sub.2 -deposited biaxially stretched film (deposit thickness: 1,000 
.ANG.) was prepared in the same manner as in Example 1, except for 
replacing the propylene/1,4-hexadiene random copolymer with a propylene 
homopolymer (MFR: 2.0 g/10 min; density: 0.905 g/cm.sup.3 ; melting point: 
167.degree. C.). 
EXAMPLE 2 
Olefin copolymer (1) (referred to as A) and the same propylene homopolymer 
as used in Comparative Example 1 (referred to as B) were melt-kneaded in 
separate extruders at 230.degree. C., fed to one die, laminated together 
in the die, and co-extruded at 220.degree. C. to obtain a 1 mm thick 
sheet. 
The sheet was stretched in the same manner as in Example 1 to obtain a 
biaxially stretched film composed of 2 .mu.m thick layer (A) and 18 .mu.m 
thick layer (B). 
The layer (A) side of the laminate film was subjected to a corona discharge 
treatment, and SiO.sub.2 was deposited thereon to a deposit thickness of 
1,000 .ANG. in the same manner as in Example 1. 
EXAMPLES 3 TO 5 AND COMATIVE EXAMPLE 2 
An SiO.sub.2 -deposited stretched film was prepared in the same manner as 
in Example 1, except for replacing olefin copolymer (1) with olefin 
copolymer (2) (Example 3), olefin copolymer (3) (Comparative Example 2), 
olefin copolymer(4) (Example 4) or olefin copolymer (5) (Example 5). 
The glow discharge conditions were varied for each stretched film so that 
all the stretched films might have an oxygen permeation of 5.0 
cc/m.sup.2.atm.day. 
Each of the SiO.sub.2 -deposited stretched films obtained in Examples 1 to 
5 and Comparative Examples 1 to 2 was evaluated as follows. The results of 
evaluation are shown in Table 1 below. 
1) Permeation Change with External Stress: 
A repeated torsion tester "Gelbo Flex Tester" manufactured by Meiritsu 
Keiki K.K. (Military specifications: MIL B 132) was used. The film was 
rolled into a cylindrical form, and the ends of the cylinder, in the 
longitudinal direction, were fixed to the clamps of the tester. Torsion 
from 0.degree. to 440.degree. was repeated ten times while compressing the 
cylinder in the longitudinal direction to 3/4of its original length, and 
oxygen permeability was then determined. 
2) Change on Fabrication: 
Low-density polyethylene having a melt index of 5 (g/10 min) and a density 
of 0.922 g/cm.sup.3 was extruded from a T-die at a resin temperature of 
320.degree. C. into a 20 .mu.m thick film and laminated on the SiO.sub.2 
deposit side of the film using a laminator. The oxygen permeability and 
haze of the resulting laminated film were measured. 
TABLE 1 
__________________________________________________________________________ 
After After 
Diene 
Initial External Stress 
Laminating 
Unit Oxygen Oxygen Oxygen 
Content 
Permeability 
Haze 
Permeability 
Permeability 
Haze 
Example No. 
(mol %) 
(cc/g .multidot. m.sup.2 .multidot. day) 
(%) (cc/g .multidot. m.sup.2 .multidot. day) 
(cc/g .multidot. m.sup.2 .multidot. 
day) (%) 
__________________________________________________________________________ 
Example 1 
3.3 5.0 3.5 7.0 5.0 6.5 
Example 2* 
3.3 5.0 3.0 7.0 5.0 6.2 
Example 3 
0.05 5.0 2.9 9.0 6.0 6.0 
Example 4 
10 5.0 4.0 8.5 5.5 7.2 
Example 5 
2.7 5.0 3.0 6.8 5.0 6.0 
Comparative 
0 5.0 2.7 340 27 9.8 
Example 1 
Comparative 
0.01 5.0 2.8 280 18 9.9 
Example 2 
__________________________________________________________________________ 
Note: *Laminated film. 
As described and demonstrated above, the crystalline olefin copolymer 
molded article with an inorganic oxide deposit suffers no reduction in gas 
barrier properties even when heat or stress is applied thereto. 
Accordingly, it is more useful as a wrapping or packaging material in the 
production of pouch-packed foods, IC packages, and other devices requiring 
enhanced barrier protection. 
Obviously, numerous modifications and variations of the present invention 
are possible in light of the above teachings. It is therefore to be 
understood that within the scope of the appended claims the invention may 
be practiced otherwise than as specifically described herein.