SE428698B

Packaging material with good permeability

Abstract

This record has no abstract on file.

SE428698B, drawing sheet 1 — Sheet 1 of 20

Term

No projected expiry on record.

10 claims: 5 independent, 5 dependent

1
Patentkrav' 1. Förpackningsmaterial med låg gaspermeabilitet, kännetecknat därav, att det innefattar minst ett skikt sammansatt av (A) en eten-vinylalkoholsampolymer med en vinylalkoholhalt av 50 till 75 molprocent och en resthalt av vinylester av upp till 4 molprocent, räknat på summan av vinylalkoholen och vinylestern, eller (B) en blandning av angiven eten-vinylalkoholsampolymer med upp till 150 viktprocent, räknat på angiven sampolymer, av minst en termoplastisk polymer av annat slag än angiven sampolymer, varvid eten-vinylalkoholsampolymeren har en endotermisk huvudtopp, som väsentligen uppfyller följande villkor:Y = 1,64X + 68,0 vari Y^ står för den endotermiska huvudtoppens temperatur (°C) vid differentialtermisk analys, och X står för vinylalkoholhalten (molprocent) i eten-vinylalkoholsampolymeren, och minst en endotermisk sekundärtopp, som väsentligen uppfyller följande villkor: 0,67X + 76,7- ä Y 2 0,40X + 40,0 företrädesvis 0,6?X + 76,7 έ Y 2 δ 0,34X + 88,0 vari Y 2 står för den endotermiska sekundärtoppens temperatur (°C) vid differentialtermisk analys och X har angiven betydelse, och att förhållandet (Rs) av ytan av den endotermiska sekundärtoppen, vilken yta representerar cal/g, till ytan av den endotermiska huvudtoppen, vilken yta representerar cal/g, är minst 2,5
2
Förpackningsmaterial enligt krav 1, kännetecknat därav, att eten-vinylalkoholsampolymeren utgöres av en förtvålad produkt, som bildats genom förtvålning av en eten-vinylacetatsarapolymer med en etenhalt av 25 till 50 molprocent och en vinylacetathalt av 75 till 50 molprocent vid en förtvålningsgrad av minst 96 %. 5. Förpackningsmaterial enligt krav 1 eller 2, kännetecknat därav, att eten-vinylalkoholsampolymeren har en gränsviskositet av 0,07 till 0,17 1/g mätt i ett blandat lösningsmedel av 85 viktprocent fenol och 15 viktprocent vatten vid J0°C. 7602548-5 46 · kännetecknat därav, att det utgöres av en film. 12. Förfarande för framställning av ett förpackningsmaterial enligt krav 1, kännetecknat därav, att det omfattar stegen:(1) att en formad struktur bildas, som omfattar minst ett skikt sammansatt av (A) en eten-vinyla.lkoholsampolymer med en vinylalkoholhalt av 50 till 75 molprocent och en resthalt vinylester av upp till 4 molprocent, räknat på summan av vinylalkoholen och vinylestern, eller (B) en blandning av angiven sampolymer med upp till 150 viktprocent, räknat på angiven sampolymer, av minst en termoplastisk polymer av annat slag än angiven sampolymer, och (2) att på så sätt bildad formad struktur hålles under temperatur- och tidsbetingelser, som tillfredsställer följande villkor: O,67X + 66,7 Up 0,40X + 30,0 företrädesvis 0,67X + 66,7 £ Y 5 ä 0,34X + 78,0 vari Yj står för värmebehandlingstemperaturen (°C) och X står för vinylalkoholhalten (molprocent) i eten-vinylalkoholsampolymeren, och t 0,5X - 20 vari t står för värmebehandlingstiden (minuter) och X har angiven betydelse, för att därvid alstra en sampolymer eller blandning med de endotermiska topparna, som anges i krav 1. 13. Förfarande enligt krav 12, kännetecknat därav, att den formade strukturen bildas genom smältformning. 7602548-5
3
4. Förpackningsmaterial enligt något av föregående krav, kännetecknat därav, att den (de) termoplastiska polymeren (-erna) av annat slag än eten-vinylalkoholsampolymeren utväljes från polyolefiner och/eller karbonylgrupphaltiga termoplastiska polymerer.
4
5- Förpackningsmaterial enligt något av föregående krav, kännetecknat därav, att det har en flerskiktsstruktur, med minst ett skikt sammansatt av (A) eller (B) och minst ett skikt sammansatt av termpolastisk sampolymer av annat slag än angiven sampolymer.
5
6. Förpackningsmaterial enligt krav 5, kännetecknat därav, att skiktet, som är sammansatt av en termoplastisk polymer av annat slag än den angivna sampolymeren, är sammansatt av en polyolefin.
6
7. Förpackningsmaterial enligt något av kraven 1 till 4, kännetecknat därav, att det omfattar en flerskiktsstruktur med ett mellanliggande skikt sammansatt av en blandning, som innehåller angivna eten-vinylalkoholsampolymer (EV), en polyolefin (PO) och en karbonylgrupphaltig termoplastisk polymer (C) i ett viktförhållande EV:PO:C från 100:25:4 till 100:100:20 och med ett skikt av en polyolefin placerad ovanpå varje huvudyta av det mellanliggande skiktet.
7
8. Förpackningsmaterial enligt krav 7, kännetecknat därav, att ett värmebeständigt och tryckhållfast skikt sammansatt av ett termoplastiskt harts bildas på det av de ovanpå placerade polyolefinskikten, som är på insidan av förpackningar, som bildats från förpackningsmaterialet i bruk.
8
9- Förpackningsmaterial enligt krav 8, kännetecknat därav, att det termoplastiska hartset i det värme- och tryckbeständiga skiktet utväljes från (i) polyestrar, (ii) polypropener, (iii) polykarbonater, (iv) metylmetakrylat-ympade akrylonitril-styrensampolymerer, metylmetakrylat-ympade akrylonitril-butadiensampolymerer och metylmetakrylat-ympade akrylonitril-styren-butadiensampolymerer, (v) akrylonitril-styrenbutadiensampolymer och (vi) polymetylmetakrylat.
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10. Förpackningsmaterial enligt något av föregående krav, kännetecknat därav, att en flaska formats genom blåsning.
10
11. Förpackningsmaterial enligt något av krav 1-9, 760254g'5 ENDOTERM —-----Δ T ----- EXOTERM

Independent claims10

759 paragraphs in 12 sections, as filed

(24) Running day

PATENT AUTHORITY (62) National application number (86) International filing date (86) Filing date for European patent application (30)

76-02-26 Application received as

£] Swedish patent application □ completed international patent application with number □ converted European patent application with number

75-03-03 GB 8809/75 (71) Applicant: Toyo Seikan Kaisha Ltd, Tokyo JP (72) Inventor: 1) M Yamada, 2) S Hirata, 3) A Kishimoto, <) S Hirata, 5) T Suzuki 6) F Canoe,

1) Ebina-shi, 2,3,4) Yokohama-shi, 5) Yokosuka-shi, 6) Mamakurashidai (74) 0mbud: AB Stockholm Patent Office (54) Name: Packaging material with low gas permeability and process for making it (56) Published publications: US 3,419,654 (264-210)

7602548-5

The present invention relates to a packaging material having extremely low gas permeability, and to a process for producing such a packaging material.

In particular, the invention relates to a low gas permeability packaging material comprising at least one layer composed of a copolymer of ethylene and vinyl alcohol or a mixture of this copolymer and at least one thermoplastic polymer, the copolymer of ethylene and vinyl alcohol having at least two thermal melting points ( at least two endothermic peaks in the curve obtained by differential thermal analysis); and a process for making such packaging material.

As can be seen from, for example, the description of US PS 3,419,654, it is known that a copolymer of ethylene and vinyl alcohol is a thermoplastic polymer which can be extruded in the molten state and which has extremely low gas permeability. When this copolymer of ethylene and vinyl alcohol is used as packaging material, e.g. in the form of a film, the distribution range of the ethylene content of the copolymer of ethylene and vinyl alcohol is narrowed and the amount of ethylene homopolymer or vinyl alcohol homopolymer present in the copolymer of ethylene and vinyl alcohol is reduced to ameliorate the defects of this polymer, e.g.

7602548-5 2 likewise the high permeability of water vapor and. the properties that are difficult to form into a film or the like, as described in GB PS 1 190 018, The simplest and most convenient way to measure the olefin distribution interval in a copolymer of an olefin and vinyl alcohol and the amount of the olefin homopolymer or vinyl alcohol homopolymer present in the copolymer by differential thermal analysis. The British patent specification discloses a copolymer of ethylene and vinyl alcohol, which copolymer has a single endothermic peak in the curve obtained by differential thermal analysis and a half value width of the endothermic peak within a specific temperature range, and this copolymer should be selected as packaging material.

The patent specification discloses that a packaging material composed of a copolymer of ethylene and vinyl alcohol, which copolymer has lower permeability to gases such as oxygen and water vapor, and which copolymer has high formability in the molten state, can be provided. However, from an industrial point of view, this material of the prior art is still insufficient, since special considerations and considerations must be made to obtain a specific copolymer of ethylene and vinyl alcohol, which copolymer has a very narrow ethylene distribution range and which copolymer contains only a very small amount of ethyl alcohol or ethyl alcohol. in the copolymer.

Surprisingly, in the research work conducted to develop excellent packaging materials, it has been found that, contrary to the prior art, a packaging material composed of a copolymer of ethylene and vinyl alcohol, which copolymer has an endothermic head and an endothermic secondary peak within specific temperature ranges in the curve obtained by differential thermal analysis; which curve varies depending on the vinyl alcohol content of the copolymer of ethylene and vinyl alcohol, has lower gas permeability than a conventional packaging material composed of a copolymer of ethylene and vinyl alcohol, which copolymer has a single endothermic peak in the curve obtained by differential thermal analysis. The present invention is based on this discovery.

The present invention relates to a packaging material which has extremely low gas permeability, which material comprises at least one layer composed of (A) a copolymer of ethylene and vinyl alcohol, which polymer has a vinyl alcohol content of 50-75 mol4-0 percent and a residual vinyl ester. of up to 4 · mole percent calculated

7602548-5 on the sum of the vinyl alcohol and vinyl ester or (B) a mixture of this copolymer of ethylene and vinyl alcohol of up to 150 weight percent, based on the copolymer, of at least one other thermoplastic polymer, the copolymer of ethylene and vinyl alcohol having an endothermic head, which essentially meets the following conditions:

Υχ = 1.64X + 68.0 wherein Y ^ represents the temperature of the endothermic head (° C) in the differential thermal analysis, and X stands for the vinyl alcohol content (mole percent) of the copolymer of ethylene and vinyl alcohol, and at least one endothermic secondary peak, which essentially satisfies the following conditions:

0.67 x + 76.7 Y2 1 0.40 x + 40.0 preferably

0.67 X + 76.7 = Y2 = 0.34 X + 88.0 wherein Y p represents the temperature of the endothermic secondary peak (° C) in the differential thermal analysis, and X has the significance given, and the ratio (Rs) between the surface of the endothermic secondary peak and the surface of the endothermic main peak is at least 2.5

The present invention also relates to a process for producing packaging materials, forming a shaped structure comprising at least one layer composed of (A) a copolymer of ethylene and vinyl alcohol, which copolymer has a vinyl alcohol content of 50 to 75 mole percent and a residual vinyl ester of up to 4 mole percent, based on the sum of the vinyl alcohol and vinyl ester or (B) a mixture of this copolymer of up to 150 wt.% based on the copolymer; of at least one other thermoplastic polymer, and (2) maintains the thus-formed structure under temperature and time conditions which meet the following conditions:

0.67 X + 66.7 - Y - 0.40 X + 50.0 preferably

0.67 X + 66.7 = Y? = 0.34 X + 78.0 wherein Yj represents the heat treatment temperature (° C) and X stands for the vinyl alcohol content (mole percent) in the copolymer of ethylene and vinyl alcohol and t = 0.5 X - 20 where t stands for the heat treatment time (minutes) and X has the meaning given.

The invention will be described in detail below.

The copolymer of ethylene and vinyl alcohol used in the present invention may be a saponified copolymer of ethylene with a lower fatty acid vinyl ester such as vinyl formate, vinyl acetate

7602548-5 or vinyl propionate, particularly saponified copolymers of ethylene and vinyl acetate. These copolymers are described, for example, in US PS 5,185,205 and US PS 5,419,654.

It is important that the ethylene-vinyl alcohol copolymer has a vinyl alcohol content of 50 to 75 mole percent and thus an ethylene content of 25 to 50 mole percent. If the vinyl alcohol content is less than 50 mole percent, the permeability of oxygen or other gas becomes high and a low gas permeability cannot be achieved, even if the copolymer has at least two endothermic peaks. Therefore, the object of the present invention cannot be achieved if an ethylene-vinyl alcohol copolymer having such a low vinyl alcohol content is used. If the vinyl alcohol content of the copolymer exceeds -75 mol%, the hydrophilic properties of the copolymer increase and the permeability of water vapor is increased and further reduces the ability of the copolymer to form in the molten state.

The degree of saponification in the polymer is of great importance for the oxygen permeability of the finished packaging material. According to the invention, it is important that the ethylene-vinyl alcohol copolymer be obtained when saponifying at least 96, preferably at least 99 0, vinyl ester units of an ethylene-vinyl ester copolymer. In other words, in order to obtain a low gas permeability packaging material, it is important that the residual vinyl ester content of the ethylene-vinyl alcohol copolymer used according to the invention amounts to up to 4 mole percent, preferably up to 1 mole percent, based on the sum of the vinyl alcohol and vinyl ester.

The ethylene-vinyl alcohol copolymer used according to the invention may be a saponified olefin-ethylene-vinyl ester copolymer which, as a comonomer, comprises a copolymerizable olefin having three or four carbon atoms, such as propylene, butene-1 or isobutylene, in an amount which is not negative. effect on the permeability of gases, such as oxygen or carbon dioxide, in an amount up to 5 mole percent, as long as the specified conditions for the vinyl alcohol content and the degree of saponification are met.

The molecular weight is not particularly critical in the ethylene-vinyl alcohol copolymer used according to the invention, and it is usually sufficient if the copolymer has film-forming molecular weight. The intrinsic viscosity of the ethylene-vinyl alcohol copolymer is usually measured in a mixed solvent, which consists, for example, of 85% by weight of phenol and 15% by weight of water, at 50 ° C. According to the invention, it is convenient to use an ethylene-vinyl alcohol copolymer having an intrinsic viscosity [η J, measured by this method, of 0.07 to 0.17 l / g.

7602548-5

The ethylene-vinyl alcohol copolymer, which is the packaging material of the invention, is characterized in that the curve obtained in differential thermal analysis of the copolymer has an endothermic main peak and an endothermic secondary peak within specific temperature ranges, which vary depending on the copolymer's vinyl alcohol content. The ethylene-vinyl alcohol copolymer is particularly marked by the fact that the specified curve has an endothermic head peak, which satisfies the following conditions:

ϊχ = 1.64 X + 68.0 wherein Y 2 represents the temperature of the endothermic peak (° C) in the curve obtained by differential thermal analysis, and X represents the vinyl alcohol content (mole percent) of the ethylene-vinyl alcohol copolymer, and at least one endothermic secondary peak; which meets the following conditions:

0.67 X + 76.7 = Y2 θΛ0 x + 40 preferably

0.67 X + 76.7 = Y2 - ° »54 X + 88.0 wherein Yg stands for the temperature of the endothermic secondary peak (° C) in the specified curve and X has the significance given.

In order to better illustrate the indicated data, the invention will now be described with reference to the drawings, in which fig. 1 shows a curve obtained in differential thermal analysis of a shaped article of an ethylene-vinyl alcohol copolymer having a single endothermic peak (melting), which copolymer is not within the scope of the invention, and Figure 2 shows a curve obtained in differential thermal analysis. of a shaped article of an ethylene-vinyl alcohol copolymer having a plurality of endothermic peaks, which copolymer falls within the scope of the present invention.

A shaped article of an ethylene-vinyl alcohol copolymer of the invention having multiple endothermic peaks as shown in Figure 2 has much better resistance to oxygen passage (oxygen barrier) than a shaped article of an ethylene-vinyl alcohol copolymer having a single endothermic peak such as that shown in FIG. Fig. 1. This fact will be evident from Table 1 of Example 1 below. A shaped article with a single endothermic peak at 182 ° C has oxygen permeability 1.14 cc / m2»Day.atm, on the other hand, while an object having an endothermic main peak at 182 ° C and an endothermic secondary peak at 105 ° C, the oxygen permeability has 0.56 cc / m« * day «atm, which is less than half the value for the specified shaped article with a single endothermic peak (the comparison was made on samples of thickness 10 µm).

ii I <I

7602548-5 6

In the ethylene-vinyl alcohol copolymer constituting the packaging material of the invention, the endothermic peak is evidently due to melting of the ethylene-vinyl alcohol copolymer, and in view of the fact that the endothermic secondary peak is in a temperature range of lower temperature than the temperature at the rising portion of the endothermic peak. area on the low temperature side and for reasons, detailed below, it is assumed that this endothermic secondary peak is due to melting of the homopolyethylene or polymer chains of ethylene-rich segments present in the ethylene-vinyl alcohol copolymer. Accordingly, the gas permeability of the packaging material of the invention is likely to be reduced as a result of crystallization of the homopolyethylene portion or ethylene-rich segments present in the ethylene-vinyl alcohol copolymer.

The endothermic peak in the curve obtained by differential thermal analysis (DTA curve) usually corresponds to the heat needed to melt a polymer's crystals. In order to achieve good resistance to gas passage in packaging material, it is important according to the invention that the surface ratio (Rs), which can be illustrated by the following formula:

the surface of the endothermic secondary peak

Rs = ---------------------------------------- 'x 100 the surface of the endothermic main peak The ethylene-vinyl alcohol copolymer of which the packaging material is at least 2.5%, preferably within the range of 5 to 20. The critical in this condition is shown in Table 2 of Example 2 below.

The disclosure of the specified GB PS 1 190 018 shows that an endothermic peak, which is present on the low temperature side of the endothermic peak formed by melting of the ethylene-vinyl alcohol copolymer, is due to the melting of ethylene homopolymers or ethylene-rich macromolecular chains, and it is likely that this theoretical reasoning also applies to the following invention. However, the disclosed description shows that a packaging material of an ethylene-vinyl alcohol copolymer comprising such an ethylene homopolymer or ethylene-rich macromolecular chain, namely, a packaging material composed of an ethylene-vinyl alcohol copolymer having several endothermic peaks has poor resistance ). By contrast, in the packaging material of the invention, the gas permeability is further lowered compared to a packaging material composed of an ethylene-vinyl alcohol copolymer having no endothermic secondary top thereon by crystallization of such ethylene homopolymer or

7602548-5 ethylene-rich polymer chain, so that a definite endothermic secondary peak is formed in the DTA curve.

It is known that the oxygen permeability coefficient (P, cirrVcm · sec · cmHg) of polyethylene can be controlled to a low level by improving the degree of crystallization, namely the density. According to Yokio Ito, Polymer Chemistry, 16, 204 (1959) and AW Myers, CE Rogers, V. Stannett & M. Szwayz, Tappi, 41, 716 (1958), the oxygen permeability coefficient (P) of polyethylene can be illustrated by the following formula:

P = PaXa11 (* = 2.2) wherein Pa represents an oxygen permeability coefficient (cnr / cm.sec'cmHg) of the polyethylene amorphous moiety, and Xa represents the volume percentage of the amorphous moiety.

According to Szwarz et al or Ito, the oxygen permeability coefficient (P02) for polyethylene as follows:

P02 · =. 1 χ 10-10 cm3/ cm · sec-cmHg (at 25 ° C).

In the present case, measurements have shown that an oxygen permeability coefficient (P02) for the ethylene-vinyl alcohol copolymer used according to the present invention (with the ethylene content of 30 mole percent) is as follows;

P02 · = β 1 x 10 cm 2 / cm · sec * cmHg (at 37 ° C in absolutely dry state).

The oxygen permeability coefficient of polyethylene is thus about 10 times higher than the corresponding coefficient of the ethylene-vinyl alcohol copolymer. Therefore, it cannot be expected at all that, although the ethylene homopolymer or the ethylene-rich polymer chain present in the ethylene-vinyl alcohol copolymer crystallizes, the resistance to oxygen permeability should be greatly improved. However, as stated above, the resistance to oxygen passage in the present packaging material can be greatly improved by using an ethylene-vinyl alcohol copolymer having a definite endothermic secondary peak as well as an endothermic main peak. This discovery is very surprising in light of the above facts.

The packaging material according to the invention may be composed of either the specified ethylene-vinyl alcohol copolymer alone or a mixture of this copolymer by up to 150, preferably up to 120% by weight, based on the copolymer, of at least one other thermoplastic polymer. Furthermore, the packaging material of the invention may either consist of a single layer consisting of the specified ethylene-vinyl alcohol copolymer or its admixture with other thermoplastic polymers, or the packaging material may be a

7602548-5 multilayer structure or a laminate structure comprising at least one layer of the copolymer or its blend and at least one layer of any other thermoplastic resin. The packaging material of the invention may, for example, be in the form of a single layer or multilayer film, a bottle, a bag, a compressible container, hose, tank or other vessel.

Any thermoplastic polymer which can be kneaded with an ethylene-vinyl alcohol copolymer and can be melt-formed into a film can be used as a thermoplastic polymer for admixture with the ethylene-vinyl alcohol copolymer used in the invention. Suitable thermoplastic polymers are, for example, olefin polymers and thermoplastic polymers containing at least one kind of polar groups consisting of carbonyl, hydroxyl or other groups and used alone or in combination. Specific examples of suitable thermoplastic polymers which can be blended with the ethylene-vinyl alcohol copolymer are mentioned below:

(1) Olefin Polymers:

Lower density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, ethylene-propylene copolymers, polybutene-1, polypenten-1 and poly-4-methylpenten-1.

(2) Thermoplastic polymers containing at least one kind of polar group consisting of carbonyl, hydroxyl or ether groups:

As carbonyl group-containing thermoplastic polymers, thermoplastic polymers containing 120 to 1400 mEq / 100 g of polymer, in particular 150 to 1200, are preferably used; carbonic acid, urea or urethane. These polymers may contain ether or hydroxyl groups in addition to the carbonyl groups. Suitable examples of such carbonyl group-containing thermoplastic copolymers are described in the specification of British Patent Application 28395/72. which are partially saponified copolymers grafted with acrylic or maleic acid, polybutene terephthalate, polybutene ephthalate / poly olyteramethylene oxide segment copolymers, polyethylene terephthalate, polylauryl lactam, polycaprolactam and the like.

According to the present invention, a mixture of the above is

7602548-5 ethylene-vinyl alcohol copolymer and at least one thermoplastic polymer, which is an olefin polymer and a carbonyl group-containing thermoplastic polymer, advantageous in that the indicated excellent low oxygen permeability attributable to the ethylene-vinyl alcohol copolymer is evident, is produced by co-extrusion of this mixture and a polyolefin obtains a bond between the mixing layer and the polyolefin layer, which bond is excellent in terms of interlaminar flaking resistance. If the ethylene-vinyl alcohol copolymer, polyolefin and carbonyl group-containing thermoplastic polymer are designated EV, PO and C, respectively, mixtures which are particularly suitable for the purpose of the invention are as follows:

(1) A mixture wherein the EV: PO weight ratio is in the range of 100: 25 to 100: 100.

(2) A mixture wherein the weight ratio EV: 0 is in the range of 100: 25 to 100: 100.

(3) A mixture in which the weight ratio EV: PO: C varies in the range of 100: 25: 4 to 100: 100: 20.

(4) A mixture wherein the weight ratio EV: (C

+ Cn) (wherein C1, Cp, .... Cn stands for different kinds of carbonyl group-containing polymers) varies in the range of 100: 2β to 100: 100.

(5) A mixture in which the weight ratio EV: (PO 2 + POp + .... + P0)ffl) (wherein POp POp, .... P0ffl stands for different kinds of polyolefins) varies in the range of 100: 25 to 100: 100.

(6) A mixture in which the weight ratio EV: (PO

+ P0ffl): (C1 + Cp + ..... + Cn) (wherein P01, POp, ... PO ^ and Cp Gp,

.... Cn have specified meanings) varies within the range of 100: 25: 4 to 100: 100: 20.

In the case that the packaging material has a multilayer structure or laminate structure, a layer of the ethylene vinyl alcohol copolymer or its mixture may be an intermediate layer or an outer or inner surface layer of the packaging material. In order to prevent moisture from adversely affecting the oxygen-blocking properties of the ethylene-vinyl alcohol copolymer, it is usually appropriate that the layer of the ethylene-vinyl alcohol copolymer or its mixture be an intermediate layer. In this case, it is advisable to use a surface layer material consisting of a thermoplastic polymer having a water absorption of less than 3.5, especially 2.5%, when the material has been allowed to stand in an atmosphere of temperature 23 ° C and a relative fuk4-0 tenure of $ 50 for five days. As an example of such a thermoplastic

76025A8-5 ίο polymer include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate or polybutylene terephthalate, polycarbonates, polyamides, and nitrile resins such as acrylonitrile-styrene-butadiene copolymers, metylmetakrylatympade acrylonitrile styrene butadiene copolymers, acrylonitrile-butadiene copolymers metylmetakrylatympade metylmetakrylatympade and acrylonitrile-styrene copolymers Since the is usually difficult to bind a layer, which is composed of only ethylene-vinyl alcohol copolymer directly to layer of such a low water absorption thermoplastic polymer, as mentioned above, e.g. a polyolefin, it is convenient to bond these two layers with an isocyanate or epoxy type binder, extrude an intermediate layer of an ethylene-acrylic acid polymer, an adhesive polyester or carbonyl group-containing thermoplastic polymer, such as an ionomer, between the two layers, when the two layers is formed upon the extrusion in the molten state, or pre-mix a small amount of carbonyl group-containing thermoplastic polymer, of, for example, in a layer of the low-water thermoplastic polymer, such as polyolefin.

When it is the question of heat-sealable multilayer films, bags or compressible containers, it is advantageous to use a structure which comprises lower density polyethylene such as the inner surface layer to be heat sealed and an outer surface layer composed of a thermoplastic polymer having a melting point exceeding the melting point of the lower density polyethylene such as polypropylene, polyesters, polyamides or the like. Suitable layer combinations in the multilayer structure or laminate structure are polyolefin / ethylene-vinyl alcohol copolymer / polyolefin, polyolefin / ethylene-vinyl alcohol copolymer blend / polyolefin, and polyolefin / blend / ethylene vinyl alcohol copolymer / blend / polyolefin.

In addition, to impart other physical and chemical properties to the multilayer structure or laminate structure with such a layer combination, such as compressive strength and heat resistance, it is possible to form a layer of a thermoplastic resin such as (1) a polyester, e.g. polyethylene terephthalate or polybutene terephthalate, (2) a polypropylene, (3) a polycarbonate, (4-) a methyl methacrylate-grafted acrylonitrile-styrene copolymer, methyl methacrylate-grafted acrylonitrile-butadiene copolymer or methylmethacrylate-grafted acrylonitrile-styrene ) a polymethylmethacrylate.

7602548-5

The packaging material; according to the invention may take the form of a multilayer structure which differs from a conventional laminate structure or a co-extruded multilayer structure formed by means of a multilayer nozzle. When a mixture of a melt of an ethylene vinyl alcohol copolymer and a melt of a polyolefin or its mixture with a carbonyl group-containing thermoplastic polymer is extruded in a molten state under such conditions that the resin melt passes through a nozzle resin passage in the form of a laminar flow and the difference the flow rate between the ethylene <vinyl alcohol copolymer melt and the polyolefin or its mixture is at least 1 cm / sec, a multilayer structure is obtained, wherein the resin composition changes in the thickness direction of the shaped structure but wherein the resin composition is substantially uniform in the planar direction of the shaped structure, as can be seen, for example, in British Patent Applications 26835/72, 28395/72, 39091/73 and 39249/73. This shaped structure is very useful for the packaging material of the invention.

In preparing the present packaging material, a structure comprising at least one layer is composed of (A) an ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 50 to 75 mole percent and a residual vinyl ester of up to 4 mole percent, or (B) a mixing this copolymer by up to 150% by weight, based on the copolymer, of at least one other thermoplastic polymer, by melting or any other known forming technique. The packaging film is produced, for example, by extrusion, molding, calendar molding, molding or in some other known manner for molding. A bottle or other vessel is produced by blow molding, injection molding, extrusion, molding or by any other known molding technique. For example, a compressible container can be made by vacuum casting a shaped film or shaped sheet into the desired shape, and a bag-like container can be made by casting a shaped film or shaped sheet into bag-like shape by heat sealing or bonding.

A multi-layer structure packaging container is produced by extrusion, blow molding or injection molding by means of extrusion devices in a number corresponding to the number of resin layers and simultaneous extrusion of these resin flows from the extrusion devices using a multi-layer nozzle. Further, a multilayer structure can be formed with an extrusion device and extrusion of an ethylene-vinyl alcohol copolymer containing

76025A8-5 mixture under the specified specific conditions.

Furthermore, a multilayer laminate, especially a laminate film, can be prepared according to known lamination techniques, such as so-called dry lamination, extrusion coating, extrusion lamination and hot melt lamination.

According to the invention, the structure so formed is kept under the temperature and time conditions shown by the following formula:

0.67 X + 66.7 = Y = 0.40 X + 50.0 preferably

0.67 X + 66.7 - Yj = 0.40 X + J0.0 wherein Yj stands for the heat treatment temperature (° C) and X represents the vinyl alcohol content (mole percent) of the ethylene-vinyl alcohol copolymer, and to 0.5 X - 20 wherein t stands for the heat treatment time (minutes) and X has the specified meaning.

Through this treatment, a packaging material with improved resistance to gas passage can be obtained.

By heat treatment of the specified shaped structure, in particular a structure formed by forming in the molten state and by subjecting the structure to the specified temperature and time conditions, arises in the DTA curve of the ethylene-vinyl alcohol copolymer, of which the packaging material according to the invention is an endothermis. A secondary peak having a surface area which varies depending on the rising temperature corresponding to the heat treatment temperature and the specific heat treatment time; and because of this endothermic secondary peak, the resistance to oxygen passage in the packaging material is improved. On the specified packaging material, this specific heat treatment according to the invention is not subjected to any such endothermic secondary peak in the DTA curve of the ethylene-vinyl alcohol copolymer, and this packaging material is much worse than the packaging material according to the invention as regards the resistance to oxygen passage.

Alternative methods may be used when it comes to subjecting the packing material formed in the molten state molding to the specified heat treatment. . For example, heat treatment can be carried out during the process of cooling the molded structure to room temperature from the molten state, but it is also possible to use a method that involves cooling the shaped structure to room temperature, raising the temperature to the specified specific temperature and maintaining the shaped structure thereof

7602548-5 temperature for the prescribed time. Heat treatment is further carried out either in one step or in several steps. As the heat treatment is carried out in several steps, as shown in Table 4, a plurality of endothermic secondary peaks corresponding to the respective heat treatment temperatures arise in the DTA curve. The heat treatment can be easily carried out in any known heating furnace or any slow cooling furnace, which furnace is provided with heating means such as IR radiation, an electric heating device, a steam based heater, a hot water heater or a hot air heater. The lowest heat treatment time is intimately related to the vinyl alcohol content of the ethylene-vinyl alcohol copolymer. For example, when the vinyl alcohol content (X) is 50 mole percent, the lowest heat treatment time is 5 minutes. When X = 60 mole percent, the lowest heat treatment time is 10 minutes and when X = 70 mole percent, the lowest heat treatment time is 15 minutes. It is disadvantageous from an industrial point of view if this heat treatment time (t) exceeds 50 minutes. It is therefore convenient that the heat treatment conditions are chosen such that the heat treatment time (t) varies between the specified minimum heat treatment time to about 50 minutes and so that the lowest oxygen permeability is obtained. Instead of such a special heat treatment, it is possible to apply a method by which a liquid volume kept within the specified temperature range is filled into the molded packaging material and this temperature is maintained for the prescribed time, or a method, according to which the packing material filled with the specified volume is subjected to the heat sterilization treatment at the specified temperature for the specified time so as to achieve the same effects as the specified heat treatment. Since it is considered that this heat treatment is intended for crystallization of the homopolyethylene or ethylene-rich segments of the ethylene-vinyl alcohol copolymer, the stated effects can be achieved by UV irradiation or electron beam irradiation, in which case the treatment time can be made much shorter than the specified heat treatment time.

It is previously known that a film of an ethylene-vinyl alcohol copolymer or the like can be subjected to heat treatment. However, this known heat treatment differs from the heat treatment according to the present invention in terms of the conditions and objects subjected to the heat treatment. US PS 5,560,525 shows that a laminate film of an ethylene-vinyl alcohol copolymer and a polyolefin is heat treated under specific conditions to eliminate a defect in this film

7602548-5 namely that the boundary portion between the heat-sealed region and the non-heat-sealed region is very weak for vibration or shock. This heat treatment is carried out for a relatively short time, less than 1 minute, and the heat treatment temperature is relatively high. Under such heat treatment conditions, as shown in the tables of the embodiments, it is impossible to obtain a packaging material having lower oxygen permeability and the thermal properties which characterize the packaging material of the present invention.

Japanese published patent application 5175/74 discloses a method according to which an ethylene-vinyl alcohol copolymer is heat treated at one. specific temperature in water or a mixture of water and an additive, such as alcohol, or in an atmosphere of particular relative humidity using an additive such as alcohol. However, this publication does not show that the resistance to passage of gases, e.g. oxygen, can be improved by this heat treatment. This heat treatment requires complicated measures to control the humidity and the like and consequently this heat treatment method is industrially disadvantageous. Since it is a multi-layer structure which, as an intermediate layer, has an ethylene-vinyl alcohol copolymer, it takes an extremely long time for the copolymer to achieve the specified specific moisture and industrial use of the specified heat treatment method is practically impossible. In the heat treatment of the present invention, on the other hand, it is completely unnecessary to use water or any other additive according to the disclosed publication, and the heat treatment of the present invention can be carried out in a very simple manner.

The packaging material according to; not only does the present invention have the advantage that gas permeability, especially oxygen permeability, is very low, but it also has many other advantages associated with the production of the material. By using industrially readily available ethylene-vinyl alcohol copolymer wherein the ethylene has a relatively wide distribution, the present invention provides a packaging material with improved oxygen permeability, and this improvement of resistance to oxygen passage can be achieved with relatively simple means.

The packaging material of the present invention can be used with good results when, without weight loss and deterioration, it is desired to preserve and store liquid, paste and gelatinous foods, such as stews, such as pre-cooked curry, pre-cooked stew.

7602548-5 borscht and meat stew, sauces such as meat sauce, cooked vegetables, fish and meat dishes, such as marinated pork, sukiyaki, Chinese pasta of meat and vegetables, Chinese hotchpotch, cooked asparagus and cream-cooked tuna, sauces such as consomé, red soup, miso soup, pork miso soup and vegetable soup cooked with oil, rice dishes such as boiled rice, rice cooked with brown beans, roasted cooked rice, fried boiled rice, pilaf and rice flour, noodles such as spaghetti, vermicelli of buckwheat, wheat vermicelli, Chinese noodles and Italian noodles, spices, e.g. for roasted cooked rice or soup on Chinese noodles. delicacies, such as flavored cooked brown beans, thick bean flour soup with sugar, and sugared and cooked beans with rice cake or fruit and jam, processed fish and meat products; drinks, such as beer, sake, whiskey, distilled beverages, fruit wines such as grape wines, alcoholic beverages such as cocktails, carbonated beverages such as cola, cider and common sodas, fruit juices such as lemon juice, orange juice, plum juice, grape juice, strawberry juice and other simple juices , processed fruit drinks, such as Nector, vegetable juices, such as tomato juice, synthetic drinks, such as synthetic fruit juices, containing a saccharide, such as sugar or fructose, citric acid, a dye and a perfuming agent, and optionally «any vitamin, as well as lactic acid drinks; spices, such as soy, sauce, vinegar, sweet thing, dressin, mayonnaise, ketchup, edible oils, misooch lado; table delicacies such as jam, butter, margarine, and bean paste; liquid medicines, agricultural chemicals, cosmetics and detergents; ketones such as acetone and methyl ethyl ketone; aliphatic hydrocarbons such as n-hexane and n-heptane; aromatic hydrocarbons such as benzene, toluene and xylene; chlorine-containing compounds such as carbon tetrachloride and tetrachloroethene; higher fatty acids; gasoline, kerosene, petroleum gasoline, fuel oil, tin, grease, silicone oil, thin oil and machine oil.

The invention will now be described in detail with reference to the following exemplary embodiments wherein the differential thermal analysis is carried out with a sample of 5 to 10 mg at a temperature control rate of 10 ° C / minute by means of an apparatus for different ialthermal analysis of microprobe, which apparatus manufactured by Rigaku-Denki Co. Ltd. (Micro DTA Standard Model No, 8025). In each example, the oxygen permeability was determined by the following method:

(1) Bottles:

Nitrogen gas was introduced into an evacuated sample bottle to be tested, and the opening of the bottle was sealed with a rubber stopper. The surface parts of the bottle opening and the rubber stopper which would be brought into contact,

7602548-5 was covered with an epoxy glue and the bottle was kept for the prescribed time period in a thermostat tank maintained at a temperature of 37 ° C and a relative humidity of 15%. Then, the concentration of the oxygen which had penetrated into the bottle was determined by gas chromatography and the oxygen permeability Q0 and calculated according to the following equation.

Each value given in the embodiments refers to a mean obtained when this test was performed on three samples.

tx Op x A wherein m represents an amount (cm 2) of nitrogen gas filled into the bottle, t denotes a period, (day) during which the bottle is kept in the thermostat tank, Ct refers to the oxygen concentration (volume percent) in the bottle after passage of t days, A denotes effective area (m) of the bottle and Op refers to the partial pressure (atm) of oxygen (0.209).

(2) Movies:

The oxygen permeability is fed with a test device for measuring the gas permeability, since the sample to be examined was a film. The sample was fixed * between two chambers in the sample apparatus. In one chamber (the low pressure chamber), the pressure was lowered by suction to a pressure below 10 mm Hg and the atmosphere of the other chamber (the high pressure chamber) was replaced by oxygen so that its pressure reached an atmosphere. The increase of pressure with time in the low pressure chamber was read by a recording apparatus and the oxygen permeability, Q02, was calculated using the recorded data. The measurement temperature was 37 ° C and the relative humidity in the high pressure chamber 0%.

Each value in the embodiments is an average value obtained by performing this test on three samples.

Example 1

An ethylene-vinyl alcohol copolymer having a vinyl alcohol content of

73.8 mole percent ,. a residual vinyl acetate of 0.8 mole percent, an intrinsic viscosity of 0.12 l / g as measured in a mixed solvent of 85 wt% phenol and 15 wt% water at 30 ° 0, a density of 1.19 g / cm 2 measured at 23 ° C and a melt index of 1.3 g / 10 min. measured at 19 ° C, melted at 200 ° 0, pressed with a high pressure oil pressure gauge (pressure gauge 20 kg / cm) and immediately set at room temperature to cool the formed film. In this way, a film A of thickness 103 µm was obtained. Separately and just after pressing, the sample was heat treated for 15 minutes in an atmosphere at 105 ° C and the sample was then allowed to stand at room temperature for cooling. This was obtained

7602548-5 a film B of thickness 105 Ri, In the same manner as described, samples were heat treated immediately after pressing for 15 minutes at 60, 80, 100, 120 or 140 ° C to form films C, D, E, F and G.

Each of the indicated test films A to G was subjected to differential thermal analysis, oxygen permeability measurement and water vapor permeability measurement according to JIS Z-0208 (calculated with the thickness of 104 µm), obtaining the results shown in Table 1.

7602548-5

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7602548-5

In the DSA curve for sample A, there was no endothermic secondary peak, but the endothermic peak was observed at 102 ° C. In each of samples B to G, however, there was an endothermic secondary peak, which peak varied depending on the heat treatment temperature, and an endothermic peak, which was considered to be identical to the corresponding peak for sample A within the error limits (182 + 1 ° C).

Example 2

A film prepared in the same manner as in the case of Sample A of Example 1 was heat treated for 15 minutes in an atmosphere held at 110 ° C to obtain a sample H. This film was heat treated for 5 minutes in the same atmosphere to form of a sample EH, A film was prepared in the same manner as in the case of Sample B except that the heat treatment time was shortened to 5 minutes to obtain sample EB. These examples, Η, EH, and EB, were subjected to differential thermal analysis and oxygen permeability measurement, yielding the results shown in Table 2, from which it is readily apparent that since the heat treatment time for samples EH and EB was shorter than for samples H and B, the ratio between the surface of the endothermic secondary peak and the endothermic main body of the DSA curve is smaller.

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7602548-5

Example 5

The same ethylene-vinyl alcohol copolymer used in Example 1 was formed into a film with an extruder equipped with a 25 mm diameter nylon screw and 625 mm length and a T-nozzle. The rotary speed of the feed screw was 65 per minute and the temperature of the nozzle was 250 ° C. The cooling roll used was such that the roll temperature had room temperature at the beginning of the film formation and the temperature amounted to 75 ° C when 5 hours had passed since the film formation had begun. The film was wound up and cooled on natural vague to room temperature. A film with a thickness of about 200 µm, made just after the film formation had begun, was designated as Sample I, and a film of the thickness of about 200 µm, which film was made after 5 hours had passed from the beginning of film formation, was designated as Sample J. A film was prepared under the same extrusion conditions as above using a water-cooled roll (cooling water temperature was about 18 ° C) and wound up and naturally cooled to room temperature to form a sample K of thickness about 200 µm. A film prepared under the same extrusion conditions as above was passed through a cooling roll maintained at 105 ° C and heat treated in a thermostat tank at 105 ° C for 15 minutes to obtain a sample L of thickness about 200 µm. Sample J was heat-treated at 60 ° C for 15 minutes to form Sample M, and Sample J was heat-treated at 80 ° C for 15 minutes to form Sample N. Sample J was heat-treated separately for 15 minutes to form Sample 0 and Sample J was heat-treated at 120 ° C for 15 minutes to form Sample P. Furthermore, Sample J was heat-treated at 105 ° C for 3 minutes to form Sample EJ and Sample J heat treated at 105 ° C for 15 minutes to form a sample PJ.

These samples I, J, K, L, Μ, N, 0, P, EJ and PJ were subjected to differential thermal analysis and oxygen permeability measurement to obtain the results shown in Table J »

From the results shown in Table 3 ', it can be seen that samples I, J and K, which did not undergo any heat treatment according to the invention, had no endothermic secondary peaks in their DTA curves, and that although an endothermic secondary peak was observed in the sample EJ DSA curve the ratio of the surface of the endothermic secondary peak to the endothermic main peak was low. A comparison between the data obtained with sample L and the data obtained with sample PJ further shows that data for the temperatures of the endothermic peaks, data

7602548-5 22 for the relationship between the peak surfaces and oxygen permeability data were consistent for the two samples within the error margins and the effect of the heat treatment according to the invention can be shown with good reproducibility even if the heat heaters differ.

7602548-5

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7602548-5

Example 4

Sample I prepared in Example 3 was heat-treated at 220 ° C for 15 minutes and cooled naturally to room temperature, and the treated film was further heat-treated at 105 ° C for 15 minutes to form a sample Q, Sample I was heat-treated at 120 ° C for 5 minutes, cooled naturally to room temperature and further heat treated at 105 ° C for 15 minutes to form a sample R. Sample I was heat-treated at 120 ° C for 15 minutes and immediately thereafter, the sample was heat-treated at 105 ° C for 15 minutes to form a Sample. Sample I was heat-treated at 120 ° C for 5 minutes, cooled naturally to room temperature and further heat-treated at 105 ° C for 5 minutes to form a sample EQ. Sample I was heat-treated at 120 ° C for 5 minutes and immediately thereafter it was heated at 105 ° C for 5 minutes to form a sample RS, Sample I was heat-treated at 120 ° 0 for 15 minutes, cooled naturally to room temperature, heat-treated at 100 ° C for 15 minutes, cooled naturally to room temperature and further heat treated at 100 ° C for 15 minutes, cooled naturally to room temperature and further heat treated at 80 ° C for 15 minutes to form a sample T, The sample I was heat-treated at 120 ° 0 for 15 minutes, immediately thereafter heat-treated at 100 ° C for 15 minutes, and immediately thereafter the sample was heat-treated at 80 ° C for 15 minutes to form a sample U. Sample I was heat-treated at 120 ° C for 5 minutes, cooled naturally to room temperature, heat-treated at 100 ° 0 for 5 minutes, cooled naturally to room temperature, and further heat-treated at 80 ° C for 5 minutes to form a sample ET, Sample I was heat-treated at 120 ° C for 5 minutes, heat-treated immediately at 100 ° G for 5 minutes, and then immediately heat-treated at 80 ° C for 5 minutes to form a sample RU. Sample I was melted at 200 ° C for 5 minutes, immediately heat-treated at 120 ° C for 15 minutes, heat-treated immediately at 100 ° C for 15 minutes, and further heat-treated immediately at 80 ° C for 15 minutes to form Sample V, Sample I melted at 200 ° 0 for 5 minutes, immediately heat-treated at 120 ° 0 for 5 minutes, immediately heat-treated at 100 ° C for 5 minutes, and further heat-treated immediately at 80 ° C for 5 minutes to form a sample RV.

All of the indicated film samples were subjected to differential thermal analysis and oxygen permeability measurement to obtain the results shown in Table 4.

This example shows embodiments of the heat treatment to form products with two or three endothermic secondary peaks. It is readily appreciated that the resistance to oxygen passage can be greatly improved by the heat treatment carried out under the conditions specified in the present invention, regardless of the method of the heat treatment or the number of endothermic secondary peaks;

In each of the samples indicated, the temperature of the endothermic main peak of the ethylene-vinyl alcohol copolymer was substantially the same as the temperature observed in the samples of Example 5.

7602548-5

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7602548-5

Remarks:

h: The term x - y means that treatment x was first performed and then treatment y was performed, and RT refers to cooling to room temperature.

kk: Measured under the same conditions as in Table 1.

xxx: first, second, and third refer to the first, second, and third endothermic secondary peaks calculated from the low temperature side, and in total.shows the sum of the surfaces of the first, second, and third endothermic peaks.

xssex: Calculated for the thickness of 200 µm.

Example 5

An ethylene-vinyl alcohol copolymer having a vinyl alcohol content of 50.6 mol%, a residual vinyl acetate of 5.7 mol% and an intrinsic viscosity of 0.09 l / g as measured in a mixed solvent of 85% by weight phenol and 15% by weight water at 50 ° C, was pressed at 180 ° C for 5 minutes with a high pressure oil pressure gauge (the pressure gauge was 50 kg / cm) and then cooled naturally to room temperature to form a film of about 100 µm thickness. The film was labeled as sample W. This sample W was heat-treated at 70 ° G for 7 minutes to form a sample X and the sample W was heat-treated at 100 ° 0 for 7 minutes separately to form a sample Y. The sample W was heat-treated at 120 ° C for 7 minutes to form a sample X. Sample Z, and Sample W were heat treated at 100 ° 0 for 4 minutes to form Sample EY. These samples W, X, Y, Z and EY were subjected to differential thermal analysis and oxygen permeability measurement to obtain the results shown in Table 5.

No endothermic secondary peak was observed in the DTA curve for sample W, but only one endothermic main peak at about 150 ° G. For each of samples X, Y, Z and EY, an endothermic secondary peak corresponding to the heat treatment temperature was observed except for the endothermic main peak at about 150 ° C, but in the case of sample EY, the ratio of the surface of the endothermic secondary peak to the endothermic main peak was not so high. so as to obtain the effects which it is intended to achieve with the present invention.

7602548-5

7602548-5

Example 6

An ethylene-vinyl alcohol copolymer (A) having the same physical properties as the copolymer used in Example 1, LD polyethylene (B) having a density of 0.924 g / cm 2 (ASTM D-1505) and a melt index of 0.5 g / min. (ASTM D-12J8) and Surlyn® A of Na+ion type (Du Font ionomer) (C) with density 0.942 g / cm 2 (ASTM D-1505), a melt index of 1.2 g / min (ASTM D-12J8) and a carbonyl concentration of 170 meq / 100 g of the polymer is used in a mixture weight ratio A: B: C of 50: 40: 10 and formed as shown in British Patent Applications 268J5 / 72 and 28595/72, to a polymer blend film of about 200 mm thickness with a laminar structure wherein the composition of the copolymer, LD polyethylene and ionomer were different in film thickness direction but substantially identical in film direction. . The thus prepared, untreated film was designated as sample BA. This sample BA was heat treated at 60 ° G for 20 minutes to form a sample BB and separately the sample BA was heated at 80 ° C for 20 minutes to form a sample BC. The sample BA was heat treated at 100 ° C for 20 minutes to form a sample BD. The sample BA was heat-treated at 105 ° C for 20 minutes to form the sample BE and the sample BA heat-treated at 120 ° C for 20 minutes to form a sample BE. The sample BA was heat treated at 100QC for 5 minutes to form a sample EBD and the sample BA was heat treated at 105 ° C for 5 minutes to form a sample EBE. Sample pieces were taken from the respective samples so that in each piece the entire thickness direction of the sample was included and these pieces were subjected to differential thermal analysis and oxygen permeability measurement, obtaining the results shown in Table

6th The ratio of Rs between the surface of the endothermic secondary peak and the surface of the endothermic main peak was determined in relation to the surface of the peak of the ethylene-vinyl alcohol copolymer alone. In the event that the surface of the endothermic secondary peak due to LD polyethylene or Surlyn®A was recorded in a temperature range approximately consistent with the temperature range of the endothermic secondary peak surface due to the ethylene-vinyl alcohol copolymer, the top surface was determined. produced by the copolymer as follows: Å (L ·)

The LD polyethylene and Surlyn ™ A in exactly the same amounts as in the indicated sample were heat-treated separately under respective conditions to determine the surfaces of the endothermic peaks of LD polyethylene and ionomer and these surfaces of the peaks were subtracted from the endothermic secondary peak of the sample to determine the surface of the endothermic secondary peak produced by the ethylene-vinyl alcohol copolymer.

7602548-5

3θ

The temperature of the endothermic main peak of the ethylene-vinyl alcohol copolymer and the temperature of the endothermic secondary peak of the copolymer, which temperature varies depending on the heat treatment temperature, substantially corresponded to the values shown in Table 1 and any deviations fall within the error margins of the experiments.

As can be seen from the results in Table 6, the required heat treatment time in this example was slightly longer than for samples composed of only ethylene-vinyl alcohol copolymer of Examples 1 to 4. It is likely that this is due to the additional heat required to heat the crystals. LD polyethylene and Surlyn® ® A.

Table 6

Heat treatment Heat heating Oxygen treatment actionability xx

Sample temp (° C) time (min) Rs x ($) (cm5 / m2'day * atm Remarks · 200 pm)

<td>BA</td><td>not heat treated</td><td> 0</td><td> 0</td><td> 1,47</td>

<td>BP</td><td> 120</td><td> 20</td><td> 4,2</td><td>shrinkage up-</td>

<td>NB:</td><td>x: same as xx: same as</td><td>in Table 1 in Table 4</td><td></td><td>stood at the heat treatment</td>

Example 7

A sandwich structure laminate film with a thickness of about 150 µπι was prepared by blow molding into a multilayer material, using as a medium film a blend film (A) composed of the same ethylene-vinyl alcohol copolymer, LD polyethylene and Surlyrr.J A, used in Example 6 in a weight ratio of 5: 4: 1 and as the outer and inner film layers (B) the same LD polyethylene used in Example 6. The weight ratio of inner layer B, intermediate layer A and outer layer B was 1: 1: 1. The film thus prepared was designated as sample LA. Sample LA was heat-treated at 80 ° C for 50 minutes to form Sample LB and Sample LA was heat-treated separately at

7602548-5

100 ° C for 30 minutes to form sample LO. Sample LA was heat treated at 105 ° C for 30 minutes to form a sample LD, and the sample LA was heat treated at 120 ° C for 30 minutes to form a sample LE. Sample LA was heat treated at 105 ° C for 10 minutes to form a sample ELD. These samples were subjected to differential thermal analysis and oxygen permeability measurement to obtain the results shown in Table 7.

In Table 7, the data for the surface of the endothermic main peak and the endothermic secondary peak are those elicited by the ethylene-vinyl alcohol copolymer.

In this example, the differential thermal analysis was performed as follows:

Part of each sample (after the heat treatment in the case of heat treated samples) was immersed for 2 to 3 minutes in an organic solvent of tetrahydrofuran, and the outer and inner layers were peeled off from the sample and the intermediate layer was subjected to differential thermal analysis. The subsequent treatments were performed in the same manner as in Example 6.

In each sample, the temperature of the endothermic main peak of the ethylene-vinyl alcohol copolymer and the temperature of the endothermic secondary peak of the ethylene-vinyl alcohol copolymer, which varies depending on the heat treatment temperature, were consistent with the data shown in Table 1 (the deviations are within the error margins allowed during the trials).

Table 7

<td>Sample</td><td>Heat treatment temp. (° C)</td><td>Heat treatment time (min)</td><td>Rs x (fy)</td><td>Acid permeability joe (cm5 / m2 -day · atm * 150 µm)</td><td>Remarks</td>

<td>LA</td><td>not heat treated</td><td> 0</td><td> 0</td><td> 5,91</td><td></td>

<td>SMILE</td><td> 120</td><td> 50</td><td> 4,5</td><td></td><td>Shrinkage occurred during the heat treatment</td>

NB:

K: as in Table 1 kh: as in Table 4

7602548-5

Example 8

In the same manner as described in Example 6, a blend film of about 200 µm in thickness was prepared having a layer structure wherein the polymer composition was different in the thickness of the film but substantially identical in planar direction, using the same ethylene-vinyl alcohol copolymer (A), LD polymer (B ), and Surlyn'—J A, used in Example 6 at a weight ratio (A / B): C of (70/30): 10. This film was designated as sample BO. Samples BH, BI, BJ, BK, BL and EBK were prepared from this sample BG by heat treatment of the sample BG under the conditions shown in Table 8. These samples were subjected to differential thermal analysis, oxygen permeability measurement and water vapor permeability feed according to JIS Z-0208, shown in Table 8 was obtained. The endothermic secondary peak induced by the ethylene-vinyl alcohol copolymer was determined in the same manner as in Example 6. The temperature of the endothermic main peak of the ethylene-vinyl alcohol copolymer and the temperature of the endothermic secondary peak of the copolymer, which peak varied depending on the heat treatment temperature, were consistent with the data, which is shown in Table 1 (any deviations fall within the error margins of the experiment).

TABLE 8

<td colspan="2">Heat Treatment Test Temp. (¾)</td><td>Heat treatment time (min)</td><td>Rs (%)</td><td>Acid permeability x (cm5 / mc «Day · atm» 200 pm)</td><td>Remarks</td>

<td>BG</td><td>not heat treated</td><td> 0</td><td> 0</td><td> 0,66</td><td>WVTRxx = 18, L</td>

<td>BH</td><td> 60</td><td> 18</td><td> 2,9</td><td> 0,54</td><td>WVTRxx = 15.9</td>

<td>BJ</td><td> 100</td><td> 18</td><td> 5,1</td><td> 0,39</td><td>WVTRxx = 13.4</td>

<td>BL</td><td> 120</td><td> 18</td><td> 4,1</td><td></td><td>Shrinkage occurred during the heat treatment</td>

NB:

x: same as in Table 4 o

xx: permeability (g / m »day · 200 µm) for water vapor measured according to JIS Z-0208

For comparative purposes, a film composed of the same ethylene-vinyl alcohol copolymer used in this example (composed of 100% copolymer) was heat treated under the same conditions as in the case of the specimens BG, BH, BK or BL. obtained

7602548-5 samples SG, SH, SK and SL were subjected to strength measurement at 20 ° 0, a relative humidity of 65% and velocity 300 mm / min using a strength measuring device for examining the strength in the extrusion direction. The results are shown in Table 9. Each of the values shown in Table 9 is an average obtained by performing the test on 10 samples. From the results in Table 9, it can be seen that - in the case of mixed films (samples from the B series) - the tensile fracture limit and the elongation at break of samples heat treated under the conditions specified in the present invention (samples BH and BK) did not differ significantly from the results obtained with the untreated sample (sample BG) and that the elongation at break for the mixed films (samples from the B series) was much higher than with films; composed of only the ethylene-vinyl alcohol copolymer (samples from the S series):

TABLE 9

<td>Sample</td><td>Heat treatment temp. (° C)</td><td>Heat treatment time (min)</td><td>Tensile breaks than so (ke / cnr)</td><td>Brotttöjning (0)</td>

<td>BG</td><td>not heat treated</td><td> 0</td><td> 205</td><td> 850</td>

<td>SG</td><td>not heat treated</td><td> 0</td><td> 300</td><td> 200</td>

<td></td><td></td><td colspan="2">Example 9</td><td></td>

<td></td><td colspan="4">A flat bottle with a wall of a symmetrical three-layer laminate</td>

structure was prepared according to known extrusion and blowing technique using a mixed laminate such as interlayer, which laminate formed from the same ethylene-vinyl alcohol copolymer (A), LD polyethylene (B) and Surlyn® A (C) in weight ratio (A / B): C of (45/55) · 10 in the same manner as in Example 6, The same LD polyethylene used in Example 6 was used as the outer and inner layers of the bottle wall. The average thickness of the bottle wall was 600 µm and the thickness ratio outer layer: middle layer: inner layer was 4.5: 1: 4.5. The bottle contained 280 ml. This bottle was designated as sample IF.

7602548-5

Samples LG, LH, II, EJ as well. ELI was prepared from this sample EF by heat treatment of the sample LP under the conditions shown in Table 10.

Each sample was subjected to differential thermal analysis, oxygen permeability measurement and water vapor permeability measurement performed on a portion cut away from the sample vial to obtain the results shown in Table 10. The surface of the endothermic secondary peak formed by the heat treatment of the ethylene-vinyl alcohol copolymer, as described in Example 7.

The temperature of the endothermic main peak of the ethylene-vinyl alcohol copolymer and the temperature of the endothermic secondary peak, which temperature varies depending on the heat treatment temperature, were substantially consistent with the data shown in Table 1.

Table 10

<td>Sample</td><td>Heat treatment temp. (° C)</td><td>Heat treatment time (min)</td><td>Rs (¼)</td><td>Oxygen permeability ä (cm2 / m2 «day • atm)</td><td>Remarks</td>

<td>LP</td><td>non heat</td><td> - 0</td><td> 0</td><td> 57,2</td><td>WVTRsä = 1.25</td>

<td></td><td>acted</td><td></td><td></td><td></td><td></td>

<td>LI</td><td> 105</td><td> 30</td><td> 4,9</td><td> 25,3</td><td>WVTRkä = 1.18</td>

<td>NOT</td><td> 120</td><td> 30</td><td> 4,3</td><td> -</td><td>the bottle deformed</td>

was eliminated during the heat treatment

NB:

x: the atmosphere in the sample bottle was replaced with nitrogen gas, the opening was sealed with a rubber stopper and oxygen permeability was measured according to the method described earlier in the text: water vapor permeability (g / m-day · 600 µm) was measured according to JIS Z-0208.

The indicated laminate bottles LE, LG and LI, samples BB of the same shape, thickness and volume described above, which were prepared from a resin blend of the same composition as the composition of the blend used in Example 8, and samples SB of the same shape, thickness and volumes described above, which were made of only ethylene-vinyl alcohol copolymer used in this example (sample composed of 100% ethylene-vinyl alcohol copolymer), were subjected to case tests to examine the material's ability to withstand impact stress. In this case, 5% salt water was filled into the sample bottle

7602548-5 and the bottle was sealed. The test bottle was allowed to stand still for two days and nights in a cold chamber, which was held at -2 ° C and the bottle was then allowed to fall on a concrete floor from the height 120 cm so that the bottle fell against the concrete floor. When the sample was not crushed, it had to fall again from the same height. The test was repeated a maximum of 10 times. Ten bottles were examined for a sample. The crushing ratio was calculated according to the following formula:

number of non-crushed bottles Crush ratio = 100 χ (1 - ^ i2 £ _lÖ_fall ------------)

The results are shown in Table 11. Of the laminate bottles (samples LF, LG and DI), no bottle was crushed even when the specified case sample was repeated 10 times, but of the bottles composed only of the ethylene-vinyl alcohol copolymer (samples SBF, SBG and SBI). all were crushed as the fall test was repeated 10 times.

TABLE · 11

Sample

Heat treatment temp, (° C)

Heat treatment time (minutes)

Crushing ratio (#)

<td>LF</td><td>not heat treated</td><td> 0</td><td> 0</td>

<td>BBF</td><td>not heat treated</td><td> 0</td><td> 50</td>

<td>SBF</td><td>not heat treated</td><td> 0</td><td> 100</td>

Example 10

A flat bottle of symmetrical three-laminate structure was prepared with an intermediate layer of the same resin blend used in Example 6, except that instead of Surlyn of 80 mole percent, a degree of saponification of 50%, an acrylic acid graft ratio of 1 a carbonyl concentration of 660 mEq / 100 g of the polymer, a melt index of 15 g / 10 min (ASTM D-12J8) and a density of 0.96 g / cm 2, and the ethylene-vinyl alcohol copolymer (A) and LD polyethylene (B), which were the same as used in Example 6, and the indicated copolymer (C) was mixed in a weight ratio (A / B): C of (45/55): 10, and the same LD polyethylene (B) as used in Example 6 was used as outer and inner layers.

7602548-5

The extrusion and blowing techniques used, the shape and average thickness of the bottle, the ratio of outer layer, intermediate layer and inner layer and the space of the bottle were the same as described in Example 9. The bottle thus prepared was designated as sample LM. This sample LM was heat treated at 80 ° C for 30 min to obtain a sample LMG ·. Both samples were subjected to differential thermal analysis and oxygen permeability measurement according to the methods described previously, obtaining the results shown in Table

12th The surface of the endothermic secondary peak of the ethylene-vinyl alcohol copolymer, which was induced by the heat treatment, was determined in the same manner as in Example 7.

The endothermic head peak temperature of the ethylene-vinyl alcohol copolymer and the temperature of the copolymer secondary endothermic peak at the heat treatment were consistent with the data shown in Table 1 and any deviations fall within the error margins of the experiment (+ 1 ° C).

<td rowspan="2">Sample</td><td rowspan="2">Heat Treatment temperature (° c5</td><td colspan="3">TABLE 12</td>

<td>Heat treatment time (min)</td><td>Rs (0)</td><td>Acid permeability (cm5 / m2 · day · atm)</td>

<td>LM</td><td>not heat treated</td><td> 0</td><td> 0</td><td> 35,5</td>

<td></td><td>These two bottles</td><td colspan="3">were subjected to case trials in the same manner as</td>

in Example 9. For each of the bottles, the crushing ratio was 0.

Example 11

A flat bottle of symmetrical three-laminate structure was prepared with an intermediate layer of the same resin blend used in Example 6 except that instead of Surlyn7 A used a block copolymer of polyester / polyether (polybutene terephthalate / polytetramethylene oxide) (C) with an initial temperature of melting 170 ° G (measured with constant pressure extrusion viscometer and a load of 10 kg), a density of 1.07 g / cm 2 (JIS K-6911) and a carbonyl concentration of 680 meq / 100 g of the polymer and mixing the ethylene-vinyl alcohol copolymer (A) and LD polyethylene (B), which were the same as used in Example 6, and the indicated block copolymer (C) in a weight ratio (A / B): C of (45/55): 10, using as the outer and inner layers the same LD polyethylene used in Example 6. The extrusion and blowing procedures, as used, the shape of the bottle and the average thickness, the ratio of the thickness of the outer layer, the intermediate layer and the inner layer 57 7602548-5 as well as the volume of the bottle were the same as in Example 9. This bottle was designated as sample LT. This sample LT was heat treated at 80 ° C for 30 min to obtain the LTG sample. Both samples were subjected to differential thermal analysis and oxygen permeability measurement according to the methods described in the present text, obtaining the results shown in Table 13. The surface of the endothermic secondary peak formed in the heat treatment of the ethylene-vinyl alcohol copolymer was determined in the same manner as described in Example 7.

The temperature of the endothermic peak of the ethylene-vinyl alcohol copolymer and the temperature of the endothermic secondary peak of the copolymer, which peak is induced by the heat treatment, were consistent with the data shown in Table 1 and any deviations fall within the error margins of the experiment (+ 1 ° C).

Both samples were subjected to the fall test in the same manner as described in Example 9. For each of the bottles, the crushing ratio was 0

TABLE 13

Heat treatment- Heat treatment- Oxygen permeability

Sample ling temp, (° C) ling time (min) Rs ($) (cm3 / m2 * Day »atm)

LT not heat treated 0 0 38.6

LTG 80 30 3.0 29.6

Example 12

A cylindrical bottle with a four-layer structure was formed according to known extrusion and blowing technique. A mixture prepared by mixing the same ethylene-vinyl alcohol copolymer (A), LD polyethylene (B) and Sprlyn9 A (C) used in Example 6 in a weight ratio (A / B): C of (70/50): 10 was used as the intermediate layer, and the same LD polyethylene used in Example 6 was used as outer and inner layers. . A mixture prepared by blending isotactic polypropylene (E) with a melt index of 1.2 g / 10 min and a density of 0.90 g / cm 2 and an ethylene-propylene copolymer (?) Having a melt index of 0.4 g / 10 min in a weight ratio E: F of 80:20 (hereinafter referred to as polypropylene) was formed into an innermost layer using another extrusion device. The cylindrical bottle thus produced was 500 ml and the average thickness of the bottle was about 0.8 mm. The ratio of the thickness of the outer layer, the intermediate layer (the blend layer), the inner layer and the inner layer (polypropylene layer) was 3.1: 1: 3.0: 13.5. The bottle thus obtained was designated as sample 4LP.

490 ml of city water was filled into the sample bottle 4LP and the opening of the bottle

7602548-5 was heat sealed with an aluminum foil laminated film and then provided with a lid. The sealed bottle was allowed to stand in an autoclave at 100 ° C and 1.5 kp / οπΛ for 50 minutes. The 4LP sample was subjected to heat resistance and compressive strength tests but no deformation, roasting or delamination was observed. The bottle subjected to the test specified was designated as the sample 4LPJ.

The city water was removed from the sample 4-LPJ and the bottle dried. Thereafter, the oxygen permeability was measured according to the method described above. Similarly, the untested vial was subjected to 4LP oxygen permeability measurement. The results are shown in Table 14 ·.

The samples are 4-DP as well. Further, 4-LPJ was subjected to differential thermal analysis according to the method described above, obtaining the results shown in Table 14-,

From the results shown in Table 14-, it is readily apparent that also in the indicated test, the endothermic secondary peak of the ethylene vinyl alcohol copolymer is formed and the oxygen permeability reduced.

TABLE 14-

<td></td><td>testing</td><td>testing</td><td>Temperature</td><td>Temperature</td><td></td><td>Syreper-</td>

<td></td><td>temneratur</td><td>time</td><td>for endothelial</td><td>for endothelial</td><td></td><td>meabili-</td>

<td>Sample</td><td>(° C)</td><td>(my)</td><td colspan="2">misk head peak misk secondary</td><td></td><td>tet (cm? /</td>

<td></td><td></td><td></td><td></td><td>därtopp (° C)</td><td>RSO)</td><td>im <day. atm)</td>

<td>4-LP</td><td>not tested</td><td> 0</td><td> 182</td><td>not detected</td><td> 0</td><td> 3,62</td>

Example 15

A flat bottle with symmetrical three-layer laminate structure (thickness ratio for outer layer: middle layer: inner layer = 10: 1: 10) was prepared according to the same extrusion and blow molding methods used in Example 9. A mixture formed by mixing an ethylene-vinyl alcohol copolymer (A) with the vinyl alcohol content of 74-, 3 mole percent, a residual vinyl acetate of 1.0 mole percent, ethylene content 24-, 5 mole percent, and propylene content 1.2 mole percent, nylon 6 (cp a relative viscosity of 3,4-measured at 20 ° C in a 98% sulfuric acid solution containing 10 g / l of the polymer and a carbonyl concentration of 890 meq / 100 g of the polymer, the same SurlynJ A (C ^) used in Example 6 in a weight ratio (A / C ^): Cg of (7O / 3O): 10 was used as an intermediate layer (the ethylene-vinyl alcohol copolymer (A) was characterized by an intrinsic viscosity of 0.15 L / g, a melt index of 1.07 g / 10 min and a density of 1.20 g / cm 2). An HD polyethylene

7602548-5 with. a melt index of 0.5 g / 10 min (ASTM D-1238) and a density of 0.945 g / cm 2 (ASTM D-1505) were used as outer and inner layers. The shape, average thickness and volume of the bottle were the same as in Example 9. This bottle was designated as sample YK.

The sample YK was heat treated at 120 ° C for 20 minutes to form a sample bottle of YKL. Both samples were subjected to differential thermal analysis and oxygen permeability measurement according to the methods described above. The results are shown in Table 15.

Furthermore, these bottles were subjected to the fall test according to the same method as described in Example 9 «The crushing ratio was 20% for the sample YK and the crushing ratio was 10% for the sample YKL. delamination was observed in the laminated interface between the outer layer and the intermediate layer or between the intermediate layer and the inner layer.

7602548-5 ¢0

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7602548-5

Example 14

A cylindrical bottle with four-layer laminate structure was prepared according to the method described in Example 12. The same IZD polyethylene used in Example 12 was used for the outer and inner layers and the same mixture used in Example 12 for the intermediate layer was also used in this example for interlayer. A polyester resin selected from the following three polyester resins was used for the innermost layer instead of the polypropylene used in Example 12:

(1) Polyethylene terephthalate having a reduced viscosity (specific viscosity / concentration) of 1.52 dl / g measured at 50 ° C relative to a 1% (wt.%) Solution of the polymer in a mixed solvent of 50: 50 phenol weight ratio : tetrachloroethane.

(2) Polybutene terephthalate (polytetramethylene terephthalate) having a reduced viscosity of 0.95 cc / g measured under the same conditions as in (1) above.

(5) Polycarbonate with a reduced viscosity of 0.82 dl / g measured at 20 ° C relative to a 0.5% (wt.%) Solution of the polymer in methylene chloride.

The extrusion and blowing were performed in the same manner as described in Example 12.

The three bottles thus prepared had a cylindrical shape and contained about 1000 ml. Each bottle had an average thickness of about 1.4 mm and the thickness ratio of the outer layer: the middle layer: the inner layer: the inner layer was 2: 1: 2: 56.

These three vials were designated as 4LPET (polyethylene terephthalate used as innermost layer), 4LPBT (polybutene terephthalate used as innermost layer), respectively. 4LPC (the polycarbonate is used as the innermost layer).

For comparison purposes, a 4LHD comparison bottle was prepared in the same manner as described above, however, HD polyethylene having a melt index of 0.2 g / 10 min (ASTM D-1258) and a density of 0.960 g / cm 2 (ASTM D-1505 ) was used for the innermost layer. The average thickness and thickness ratio of this bottle was the same as described above.

Each of these bottles 4LPT, 4LPBT, 4LPC and 4LHD was filled with 900 ml of urban water and each bottle was subjected to heat resistance and compressive strength testing according to the methods described in Example 12 under the same test conditions as in Example 12. The results are shown in Table 16, wherein the designation 90 "means that deformation, crushing or delamination could not be observed and

7602548-5 designation X indicates that such a defect was developed. TABLE · 16

<td>Bottle</td><td>Deformation</td><td>crushing</td><td>Delamination</td>

<td>x:</td><td>expansion of the bottle</td><td>the bottom was extreme</td><td>and the bottle</td>

could not stand straight on a table.

The urban water was removed from the bottles, which were subjected to the indicated tests for heat resistance and compressive strength, and the bottles were dried in vacuo at 25 ° C for seven days. Oxygen permeability was measured according to the method described above on all of these bottles. For comparative purposes, the oxygen permeability of the bottles was measured prior to testing for heat resistance and compressive strength. The results are shown in Table 17.

Each bottle was then subjected to differential thermal analysis. The results are also shown in Table 17 »

From the results reported in Table 17, it is seen that the endothermic secondary peak was formed in the ethylene-vinyl alcohol copolymer and that oxygen permeability was reduced.

7602548-5

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76J2548-5

Contents12

22 members in 13 offices

This recordMember, by publication datePriority claim3 more offices are in the list below

Priority claims4

Priority claims
Document	Office	Kind	Date
880975	United Kingdom	A	1975-03-03
880975	United Kingdom	A	1975-03-03
880975	–	–	–
GB19750008809	–	–	–

Members22

Family members, oldest first
Document	Office	Kind
BE839152A	Belgium	A	1976-07-01
SE7602548L	Sweden	L	1976-09-04
FR2302933A1	France	A1	1976-10-01
JPS51112694A	Japan	A	1976-10-05
AU8528675A	Australia	A	1977-04-07
GB1489635A	United Kingdom	A	1977-10-26
ZA761293B	South Africa	B	1977-10-26
US4082854A	United States of America	A	1978-04-04
CH610570A5	Switzerland	A5	1979-04-30
SU664541A3	Soviet Union (until 1991)	A3	1979-05-25
JPS55156579A	Japan	A	1980-12-05
CA1091848A	Canada	A	1980-12-16
JPS5679130A	Japan	A	1981-06-29
FR2302933B1	France	B1	1981-11-13
IT1055983B	Italy	B	1982-01-11
JPS5748459B2	Japan	B2	1982-10-16
JPS5748460B2	Japan	B2	1982-10-16
HK45282A	Hong Kong, China	A	1982-11-05
SE428698BThis record	Sweden	B	1983-07-18
JPS5995874A	Japan	A	1984-06-02
JPS6327182B2	Japan	B2	1988-06-02
JPH0678459B2	Japan	B2	1994-10-05

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	Event	Code
1996-05-13	Patent has lapsedLapsedNUG	NUG
1995-01-31	Patent in forceNAL	NAL

Packaging material with good permeability

Abstract

Term

TO3 09

IN

WE WE

NB:

TABLE 8

NB:

TABLE 9

NB:

TABLE 13

LTG 80 30 3.0 29.6

TABLE 14-

76J2548-5

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