DE2331519A1 - THERMOPLASTIC CONTAINERS AND THE PROCESS FOR THEIR MANUFACTURING - Google Patents

Description

DR. BERG DIPL.-ING. STAPF

PATENT LAWYERS 2331513

8 MONKS 8O. MAUERKiRCHERSTR. 45

Dr. Berg Dipl.-Infl. Stopf, 8 MOndien M, Mouerkircherstrofl 45 Your reference Your letter Our reference Date £ Οι «ΜϋΐΙ 1973

Lawyer file? 3 Ö63
Be / Sch

Kth / 1 Corporation Hiohmoiid / USA

"Triermoplastic Containers and Processes for Their

Manufacturing ¹¹

The present invention relates to containers made from thermoplastic Materials are made. In particular, the invention relates to the manufacture of containers or ! • 'tabs with cleverly designed, formed from at least two layers, with one of the layers here as J> i: jt-bearing layer and the other as a shielding or

(ϊ:. ί: β ikio-A piua 309881/0984 -2-

H1 34

ORlQlNAL

ρ _

Barrier layer is called.

Containers and bottles of various types made from thermal plastic materials are known. Containers with unmasked walls, ie those with at least two ocriichten. Different plastic preparations are also available. In British Patent 1 233? 77 una ^r 3 hoil to Γ-see patent application 71/15611 containers are described with tnenr- layered "Vandungen. In the British patent, a layered sheet formed from a load-bearing rail and a iliissence barrier layer is subjected to a compression set. In the method of the Dutch patent application, a multi-layer plastic layer board is tnermisen. deformed, one laminate of the panel being a thermoplastic material with honing barrier properties manufactured by VxBtron Corporation and marketed under the trademark Barex 210 and the other being polystyrene.

In various other patents, containers are provided with walls made up of at least two distinct layers Have plastics described. In U.S. Patent 2,710,987 there is blow molding of plastic containers described, which have two laminates of different, unspecified plastics. In the U.S. Patent 3,140,004 are similarly cleaned.

3 0 ^f ; fi 8 1/0 0 8 4

ji, for example an inner size of isotactischeiii Polyethylene and an outer layer made of isotactic polypropylene.

Although plastic containers with layered walls, like carried out, are well known, such containers have not found particular approval. Although different Combinations of materials and processes for the production of multilayer plastic containers are available, Process and container are not used to any significant extent. The prior art containers do not seem to have the desired combination of strength and impermeability or resilience Exhibit permeation.

With the method of the present invention it is possible to produce an improved product over the previous containers to manufacture. According to the method, a container is produced by blow molding which has at least two layers in the walls, one of the layers being a load-bearing layer and the other being a wall with barrier properties is made of a thermoplastic interpolymer resin of the nitrile type, i.e. in which at least 50% by weight of nitrile is used, is produced. Between the walls no glue is necessary and this is a positive factor, as will be explained below. In a preferred Embodiment of the products of the invention is

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2331513

-A-

Benslter a narrow-necked bottle. The Benfilter are characterized by a combination of values of recognized physikaliscnen properties, including bursting or breaking strength, Fall ochlagfertigkeit / iderstami against Creep ¹ 1 or deformation, carbon dioxide, oxygen and '/ asserpermeabilität, as well as resistance to vertical loads thereby meeting performance requirements particularly required for packaging of beverages such as carbonated soft drinks and beer. The meaning and the achievable values of the physical properties described above are described in detail below.

The following materials are generally selected for the layers. For the load-bearing layer one Polystyrene and in particular is a copolymer that Contains styrene and acrylonitrile, and suitable types of polymers are discussed below. A mixed polymer with at least 50% by weight of a polymeric nitrile material is provided as a liquid barrier layer, the preferred nitrile component being acrylonitrile or methacrylonitrile. Various other unsaturated Monomers can be used as further components for the copolymers of the nitrile type, as follows will be explained in detail.

Plastic containers according to the present invention

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illustrated by the accompanying drawings, wherein Figure 1 shows a typical container with. narrow bottle neck in shows a perspective view, Figures 2 to 4 a thermoplastic container according to the invention or a Show a portion of the same in cross section and FIG. 5 shows a plastic container according to the invention in perspective Partial view shows.

Referring to Figures 1 and 2, the container 10 has a narrow neck portion and a screwed-on closure. FIG. 2 shows in section the load-bearing, relatively thick-walled layer and an inner barrier layer 12. Screw threads 15 are provided for the engaging closure 14.

Tn figure ^ is the upper one. Part of a narrow-necked bottle container shown in section, which differs in the design compared to that of Figure 2 in that it has a. z \ i enables · ..

T-! ; - ' ^: ■■ "■ 4 int a container 20 partially shown in section, where üie:; pr has three layers, rrimlich 11, 12 and 13. In this particular embodiment there is a liquid barrier layer 12 between the load-bearing layers 11 and 1 ^. As in the embodiment of the container of Figure .-. 3 ν, the bottle neck has a fulls tr and 19, in which a cap engages.

3 (J · i "i 8 1/0 9 8 / * 'S ^ D ORKHNAL -6-

The process used to make the plastic container is commonly referred to as blow molding and various changes to this general procedure are known. The injection blow molding process, as described in U.3.-Patent 3 011 216, is suitable. Another particularly desirable method is blow molding, by means of extrusion Preform or blank is formed, which is then blow-molded in a multi-part molding tool, namely a such a mold that has two halves on v / e, each has one half of the exterior of the container as recesses. These halves are pressed around the molding and it Air pressure is used from the inside to force the hot molding into the shape of the mold formed in this way

Blow molding is a particularly valuable process, as it enables narrow-necked bottles to be produced, as required by the beverage industry, especially for such beverages; packaged under pressure, such as carbonated soft drinks, beer and the like.

To illustrate the process and product of the invention, a number of containers or bottles were used as follows described, manufactured and thereafter in terms of the required strength and physical properties

examined.

30ΜΠ81 / 0984

To produce the containers, two different extrusion presses were connected to form a coaxially working pipe-drawing mold suitable for producing the blank. The load bearing laminate of st / rol acrylonitrile copolymer was extruded through a 6.3 cm (2 1/2 inch) Prodex extruder (Prodex Corporation) at a length to diameter ratio of 24: 1. A single stage screw press with a 2.2: 1 compression ratio was used. The Prodex press cylinder was operated to create four temperature zones. Zone no. 1 had a temperature of 199 ⁰ C (39O ⁰ P) _1, zone 2 had a temperature of 20 4 ° C (400 ⁰ P), zone 3 had a temperature of 221 ⁰ C (43O ⁰ P) and zone 4 had a temperature of 215 ° C (420 P). A fitting on the die was used to connect the extruder outlet of the Prodex extruder (6.3 cm) to the 19 mm die inlet of the coaxial die. The connector was maintained at a temperature of 232 ⁰ C (45O ⁰ P) and the coaxial die was also kept at 215 ⁰ C (420 ⁰ P) · The temperatures of the zones referred to advance and the fastening varied during the course of the process by about 6 to 12 ⁰ C (10 to 2Q ⁰ P).,

The fluid barrier was made using a 38 mm NHM extruder extruded with a length to diameter ratio of 20: 1. The NSM extruder had a single stage Screw press and a compression ratio of 3: 1 · Der

3 0; 881 / 098A

- ο -

NRK cylinder of the extruder was operated so that two temperature zones were formed, the first 171 ° C (34O ⁰ P) and the second 188 ° C (370 ⁰ F) was obtained. A fitting was used to connect the 38 mm nozzle outlet of the IiRIu extruder to the 19 mm nozzle inlet of the coaxial nozzle. The connector was held at a temperature of 204 ⁰ C (40O ⁰ F).

The outer and load-bearing layer was a copolymer of styrene and acrylonitrile (SAN). The styrene / Aerylnitril-Kischpolymerisat used in the following examples contained about 30 wt. Fa acrylonitrile and the balance styrene. The styrene-acrylonitrile copolymer used here was manufactured by Dow Chemical Co. and marketed under the trademark "Tyril 880". '

The liquid barrier layer was a preparation obtained by polymerizing in an aqueous medium 100 parts by weight of a mixture of (a) 70 to 95 parts by weight of acrylonitrile and (b) 30 to 5 parts by weight of methyl acrylate in the presence of 1 to 20 parts by weight parts by weight of (c) a copolymer of butadiene and acrylonitrile obtained, wherein the copolymer 60 to 80 wt. io polymerized butadiene and 40 to 20 wt. ^ contains polymerized acrylonitrile, under the trademark "Barex 210" manufactured by standard Oil of Ohio and is described in U.S. Patent 3,426,102.

Two-layer blanks with an outside diameter of approximately 3 0: 1081/090 ^ ■ -9-

2.5 cm was extruded from the coaxial nozzle. The inner liquid barrier layer had a thickness of about 0.30 to _r O mm and 35 mm, the outer layer of about 1,650. The blanks consisted of an inner cylinder of a liquid barrier layer, which is coated or laminated with an outer cylinder made of a copolymer of styrene and acrylonitrile. The blanks were allowed to cool to room temperature and then reheated to the temperature given in the examples.

All the bottles in the row were 171 mra high and had one Diameter of 60.3 rom and they were standardized .283 large, smooth-walled bottles for soft drinks and beer. The bottles could hold about 0.311 1, however, it is common with this type of bottle for about 0.028 liters to remain empty. All bottles were see-through.

During the manufacture of the bottles, the blank was provided with a bottom closure, stretched lengthways and he received a neck-end treatment prior to the end-blow treatment. The bottom seal was attached by sliding the hot blank down into a cylindrical recess with a hemispherical bottom pushes until a lock is made. Through this working process the end walls are uniformly bent towards the center so that changes in the wall thickness in the subsequent

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Blow deformation can be reduced and compensated for.

The neck end treatment is carried out on the opposite side opposite the Bodenversohluß in the Veise that the halves of a multi-part mold, which have the desired outer shapes of the neck and the .Vulrandes, are pressed around the end of the blank. The stretched, sealed, and necked blank was then placed between a pair of mold halves which were sealed. Air pressure of 5.2 to 8.0 kg / cm '(60 to 100 psig) was used as needed through the neck opening to form the bottles. The molds were then opened and the resulting bottle cooled. These working methods were, of course, carried out at elevated temperatures in order to enable the thermoplastic shaping of the bottles. Typical temperatures were in the range of 120 to 15O ⁰ C (250 to 300 ⁰ F).

A number of bottles were made using different blank weights according to the procedure described above produced and tested for the various desired behavioral properties. The results are in the The following tables TT to TV are given. Other flaocnen were produced according to the previously described generally customary processes, except that the external load-bearing Layer was polystyrene. In this series, the barrier layer in the blank was about 0.76 mm and the outer polystyrene, load-

-.11-3s ^; H8 1/098 /,

load-bearing layer about 2.54 mm thick. In the finished container, the layers had a thickness of 0.15 to 0.20 ¹ OZW. 0.43 to 0.51 mm.

Dine arbitrarily selected empty bottle has been used several times 4? Dropped cm high with only occasional insignificant cracks in the polystyrene. Other empty bottles were allowed to fall from 0.9, 1.8 and 2.4 m, splintering and breaking with each fall, however the liquid barrier did not break and. therefore any liquids would not have leaked from the bottle can. A number of sample bottles, blow molded at different temperatures, were cut open. The two layers were separated and the following physical properties were determined

tells.

Table I.

Liquid barrier - yield strength

Strength module kg / cm

psi

modulus of elasticity

Polystyrene yield strength

Strength module kg / cm

psi

modulus of elasticity

Blow molding temperatures

* 120 ° C

150 ⁰ C

(3ÖÖÖP

1100 (15700)

65800 (936000)

728 10360

633 (9000)

49600 (705000)

653 9290

45500 50800 (648000) (723000)

633 (9000)

45700 (650000)

641 9120

39300 (559000)

The temperatures given in Table I give the. 3ü -, 881/0984 -12-

Temperatures at which the various bottles were subjected to compression molding.

The containers and bottles formed in accordance with the present invention have high and satisfactory values certain behavioral characteristics. The ones in question Factors are considered important in the beverage industry in terms of overall behavior. The following Table gives further behavioral properties, with the respective Reason for interest in this particular variable

len is specified.

Rapid burst
or breaking strength

Drop impact resistance

Creep or
Deform

Carbon dioxide permeability

A measure of the absolute resistance of a container to Breakage caused by internal pressure at a given temperature

A measure of a container's ability to withstand shock loads

A measure of the deformation of a container when it is filled with a standard liquid a controlled temperature is filled

In soft drinks and beer and some wines, which are under carbon dioxide pressure, this may be applied or formed itself, the resistance of a container with respect to loss by permeation of this component importance yon

^ 81/0984

Desired height

at least
8 kg / cm
(100 psig)

at least 0.6 m (2 ft.)

less than $ 10 at 37.8OC (100 ⁰ F), at 6.25 kg / cm (75 psig) for 168 hours

Less than 15 $ vol in 45 days at 2.4 kg / cm ^ (20 psig) and 24 C (75 ⁰ F)

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'- 13 -

Oxygen permeability

Water permeability

Resistance to vertical loads

The resistance to oxygen permeability is often important, because the ingress or egress of this gaseous element is possible the taste characteristics can change.

Important as a measure of general resilience versus loss

This is necessary as the physical one required in the given case Strength, a measure of a bottle's ability to withstand vertical loads to withstand that sometimes occur in stacking. It continues to be a measure of resilience against stresses that occur during the filling of a bottle and the closing with a gas-tight ^ closure occur.

less than 1 VoI, Ji in 45 days at one atmosphere pressure and 24 ⁰ C (75 P)

less than 1 vol. ^c / o in 45 days when the container is exposed to ^{50% relative humidity at 23 °} C (73 ^{° F).}

159 kg (350 lb).

The following procedures were used to determine the behavior of the bottles:

Bursting or breaking strength - the container was completely filled with water and connected to a pressurized water pipe by means of a tight connection. A registration device with readings up to

at 22 kg / cm (300 psig) with increments of 0.14 kg / <

cm

3 C '.: H 8 1 / Π 9 8 L

-14-

was used in the line. In carrying out the experiment, the pressure became uniform at one speed of 7 kg / cm (100 psig) per minute until the container ruptures and the pressure obtained at that point is that Test result.

Impact Resistance to Falling - This "falling" factor is determined by filling a container to its normal level with water, applying a gas pressure of 4.5 kg / cm (50 psig) and sealing it. The sealed container is dropped onto a hard surface from progressively greater heights until it breaks. The height increments are usually 0.3 m per change.

Creep test - This measurement of small volume changes at elevated temperatures is carried out with the bottle or bottles in a closed chamber equipped with a thermostatically controlled heating device and a fan. The bottle under test is filled to the top with water and weighed, the bottle itself having been weighed beforehand. The filled bottles are then attached to an air line. After the interior of the chamber and the contents of the bottle have been brought to the desired examination temperature, a standard pressure is applied to the contents of the bottle via the air line. After a certain duration of the experiment, the bottles are removed, refilled with water and weighed.

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The increase enables an immediate calculation the increase in volume caused by any deformation of the container at the test temperature

Carbon Dioxide Loss - Bottles are filled to normal level with water · Sulfuric acid and sodium bicarbonate are added in a prescribed amount to make the desired volume of carbon dioxide percentage.

The bottles are connected to a pressure measuring device and sealed tightly. The pressure is applied to the measuring device periodically read and the percentage pressure loss calculated.

Water loss - The bottles were first filled with water to the prescribed level. When the bottles are to be checked for carbon dioxide pressure, a small amount of acid and sodium bicarbonate are added to produce the desired carbon dioxide pressure. The bottles are then capped and weighed. The bottles are weighed from time to time and the percentage of content lost is calculated. The experiment was conducted under a controlled atmosphere of 23 ° C (73 ^° F) and 50% relative humidity.

The behavior information of the bottles for those described above Tests are given in Tables II to IV below. Specimens were examined with different Total weights as indicated, this being by

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3 0 i Μ 81/09 0 ^

different overall wall thicknesses occurred. At this· Investigations was the load-bearing layer the 3t, / rol-acrylonitril-LIißchpolymerisat, as previously stated, and the leakage lock "Barex 210" as previously stated.

-17-3 «J i P, 8 1/0 9 8 t>.

Weight
(δ) At-
za / il
ge
checks deformation Tabel TT Bursting 0
100
100 by- .as s er loss Ver 25th
33
40 5
4th Number of plascaes that 1.5m fixed.
12.2 kg /
cm scnn. / Ό ητο 'ΐ * after tical passed the attempt jia-batZ 30th
50
0 Burst
firm—
speed ρ
kg / a Llonat 90 days
gene loading
burden
159 kg
'ß> be
stood 1 week 1 day 1 tax
38®C 49 ° C 60 ⁰ C
6.25 kg / 7.3 kg / a, 3 ₂ kg
cm * cm cß case 8.0
14.0
16.3 0.33 0.9 100 at
game
No. 5 3 1
4 44 0.9m passed 1
2
3 100
80
67 p'all

The deformation was less than 10, ό

NJ CjJ

U)

CO

to CD

material Table ITT Avg COp rate of loss
in -μ per month example
No'. SAIT / Barex 210 weight
(δ) 3.8 4th ti 33 3.8 5 ■ •1 33 4.3 6th η 33 2.8 7th rr 35 8th 33 cut ^ .2

Initial pressure = 4.5 kg / cm (50 psi ^;)
Corrected with regard to sealing leakage

N) U) U) *

Example
No. weight
(C) Temperature of
Blow molding (300) Table IV Percentage ζ passed 7th 34 149 (275) anyway
: n 1.5 m
height from Bernten ₀
12.2 kW
(160 nsis) 8th 34 135 (260) ?Alles
0.9
height 0 67 9 34. 127 (250) 67 8th 83 - co 10 34 121 75 67 100 33 33 100 to
OD 67 O
OD
CO

IV) O

cn co

_ 20 - 2331513

It can be seen from Table TT int that, in the case of bottles in eggs , the sizes used in the tests, the 25 g weight bottles were insufficient to fail the creep (deformation) test. In contrast, passed bottles with 33 or 40 g per container, the Verforrnungsuntersuchung at 100 and with όΟρ (being less than 10 / ^ strength Volumveränderung at 37.3 ⁰ C (10O ⁰ F), 6.25 kg / cm ² (75 psig) and weekly exposure). It is also of particular interest that the 33 g bottles were more successful in terms of the number that passed the 0.9 m drop test versus the 40 g bottles. It should be noted, however, that the test results were made with a fall height of 0.9 m, so that all samples in Table II showed a high percentage of effectiveness with regard to a fall test with a height of 0.6 m. The water permeability test was quite good for the 33 g bottles, as the percentage loss after 90 days was less than 1 volume. In addition, the vertical load tests on 33 g bottles showed that they could withstand a vertical load of 159 kg per bottle. Further investigations on the 33 g bottles can be found in Table IV and the following tables, it being seen that the loss of carbon dioxide in

an initial pressure of 3.5 kg / cm for the first five examinations was only 3.20 per month.

A particular object of the process is that

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the physical. Properties are promoted by the formation of a biaxial orientation of the two layers of the container walls. In general, this orientation is achieved by pulling the polymer material "at a suitable intermediate temperature at which the thermoplastic material is resistant to deformation but is sufficiently flexible to allow the necessary change in proportions without breaking, V / ie through the Angar.cn. ·· {., <-vu ·· <> !. ». / er 'jnnter Temy.f raturboi'oic-'i ■ for the formation of the planchen and the pole _f ; nerin- .:. t 1? 0 to 150 ⁰ C (250 to 300 ⁰ P), although different bottle sizes or shapes or different specific layer materials may require a setting above or below this range.

, lic stated above, the liquid barrier layer should contain at least 50/5 polymeric nitrile monomer component represented by the general formula

GH ₀ = C - CN
² I.

Λ.

can be represented v / orin X is hydrogen, an Ilalogen or a lower alkyl group with up to 4 carbon atoms. With regard to the monomers polymerizable with such a nitrile monomer, suitable types are esters, vinyl olefins, aromatic olefins, vinyl ethers, halogenated alpha-olefins or vinyl esters. As an accessory

-22-30ί; 881 / 098Α BAOORlQtNAL

A variety of such Nischpol.verrierisate can therefore be given: Acrylonitrile, copolymerized with inletnyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl metriacrylate, alpha, methyl acrylate, vinyl acetate, vinyl acrylate, vinyl acrylate, vinyl acrylate, vinyl acrylate, vinyl acrylate, vinyl acrylate, vinyl acrylate, vinyl acrylate, vinyl acrylate, vinyl acrylate 'Tnylene, propylene, isobutylene, 1-pentene, 3-I-ethyl-1-pentene, 4 --'-fitayl-1-pentene, vinyl chloride, vinyl bromide, vinylidene chloride, styrene, alpha-r.iethyl3f.yrol, Vinylethylätfier, Yinylpropyläther, Vinylhexyläther, Vinylc / clohexylöther, Vinylben? ;; /! ätner, 4-C "chlorotyrol, 4-r5ro:! is; ^r rol or? .4-dimethylotyrol.

7 / If the nitrile mono-methyl ether nitrile irt, it can be present in the I-inch polymer in a no high proportion such as 98 or 99 Iol> i, while if acrylonitrile is used, the proportion bic to 90 Ποί, ϊ concerns.

In another variant of the copolymers of the nitrile type, the proportion of up to 50% by weight of the nitrile monomer is a dicyanobutene monomer, such as 1,3-dicyano-1-butene, 1,4-dicyano-1-butene or 2,4-dicyano-1-butene or a mixture of two or more diene isomers. A typical polymer of this type is, for example, acrylonitrile / 1,4-dicyano-ibuteny-ethyl acrylate or methacrylonitrile / 4-dicyano-1-butene / propylene.

Are as another kind of useful riperrschichtmaterialien

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3 0 ^ 881/090 ^

to mention the graft polymers in which the preceding nitrile monomer or the monomer mixtures and the coraonomer are polymerized in the presence of a rubbery or elastomeric substrate, whereby a grafting takes place. A variety of such polymeric materials are described in U.S. Patents 3,426,102, 3,451,538, 3,540,577, 3,580,974, and 3,615,710.

Adhesives can be used to bond the various layers. In general, and particularly in the manufacture of narrow neck bottles, adhesives are undesirable for various reasons. First, of course, the use of an adhesive is more expensive. Second is the lack of an adhesive in terms of that. repeated use of the container is advantageous. It has been found that the bottles of the present invention can be readily ruptured mechanically to reveal the outer load bearing layer as fragments, with the inner layer remaining essentially intact. The fragments are easily separated from the barrier layer, allowing the two streams of the different polymer resins to be produced. Since both materials are thermoplastic, they can be individually melted and reused to make new bottles or other useful items.

Splitting by breaking has particular value in

-24-309881 / 0984

narrow-necked beverage bottles. With such forms, da serves the layers are not glued together, the shape of the body, i.e. the conicity in the neck part, to hold back the inner layer tightly.

Although the splints are not necessarily adhesive to one another are connected, it has been found that due to the manufacturing steps there is no visible connection area can be seen between the splints at least during normal visual observation. The visual and aesthetic Appearance of a container, especially of course a transparent container, is preserved.

-Patent claims-

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3 0: ■: P 8 1/0 9 8 /,

Claims (11)

Patent claims: Blow-molded plastic container with layer walls (laminate), of which at least one of the layers is polystyrene or a copolymer of styrene and acrylonitrile and another layer is a liquid barrier, characterized in that the container has a rapid bursting or breaking strength of at least about 8 kg / cm (100 psig), a case-ätoßfestigkeit of at least about 0.6 m, a volume change of less than about $ 10 has when it kg a temperature of 37.8 ⁰ C (10O ⁰ F) and a pressure of 6.25 / cm (75 psig) 168 hours, a carbon dioxide permeability of less than about 15 volume $ in 45 days, an oxygen permeability of less than about 1 volume $ in 45 days, and a water permeability of less than about 1 volume $ in 45 days. 2. Container according to claim 1, characterized in that the container is transparent. 3. Container according to claim 1, characterized in that the layer is composed of a copolymer is formed containing from about 50 to about 85 wt. $ styrene. 4. Container according to one of the preceding claims, characterized in that the liquid barrier layer is a copolymer which is at least 50 30H881 / 0984 ~ ²⁶ " polymeric nitrile material, the nitrile monomer has the general formula below CH ₉ - C CN, wherein X is hydrogen, a halogen or a lower alkyl group with up to 4 carbon atoms. 5. Container according to one of claims 1 to 4 d a d u r ch marked i without t- that the liquid barrier layer is a luaterial that is produced by! folynerization in an aqueous medium of 100 parts by weight of a mixture of (a) about 70 to about 95% by weight of acrylonitrile and (b) about 30 to about 5% by weight of i, iethyle, acrylate in the presence of about 1 to about 20 parts by weight of (c) a polymerizate of butadiene and acrylonitrile is available, the iuischpolymerisat about 60 to about 80% by weight of polymerized butadiene and about 40 to about 20 wt.> o polymerized acrylonitrile contains. 6. A method of making a container having a quick burst strength of at least about 8 kg / cm (100 psig), a fail break strength of at least about 0.6 m, a volume change of less than about 10, a has, when subjected to a temperature of 37.8 ⁰ C (100 ⁰ F) and a pressure of 6.25 kg / cm (75 psig) for 168 hours is subjected to a carbon dioxide permeability of less than about 15 by volume _{α ψ} in -27- 3 (J: ₃ β 8 1/0 9 S U Days, an oxygen permeability lower than about 1 vol. $ In 45 days and a lower water permeability than about 1 vol. "Yes in 45 days, the container having a load-bearing layer made of polystyrene or a copolymer of styrene and acrylonitrile and a liquid barrier layer, a copolymer which is of wenigstens.50 wt. ^c fo a nitrile of the general formula CH ₀ = C - CN ² I X wherein X is hydrogen, a halogen or a lower alkyl group with up to 4 carbon atoms, thereby characterized in that one has a layered blank with the load-bearing and the fluid barrier layer forms, the blank is stretched in the shape of a container and blow molded and thus a biaxial one Orientation causes. 7. The method according to claim 6, characterized in that the load-bearing layer of the blank about 4 to 40 times the thickness of the liquid barrier layer. 8. The method according to claim 6, characterized in that the load-bearing layer on the Outside of the container and the liquid barrier used on the inside of the container. 309881/0984 - 28 - 9. Thermoplastic container, characterized in that the container is made by blow molding and its walls consist of at least one layer made of polystyrene or a copolymer of styrene and acrylonitrile and another layer which is a liquid barrier layer, the container having a rapid breakage strength of at least about 8 kg / cm (100 psig), has a drop impact strength of at least about 0.6 m, a volume change of less than about 10 $ when exposed to a temperature of 3718 ⁰ O (100 ⁰ F) and 6, Subjects to 25 kg / om (75 psig) 168 hours, a carbon dioxide permeability of less than about 15 vol. # In 45 days, an oxygen permeability of less than about 1 vol. # In 45 days, a water permeability of less than about 1 vol. # in 45 days and has a vertical load strength of at least 159 kg (350 pounds). 10 »A method for forming ron containers according to claim 9, characterized in that the container is formed from a blank, the layers of a polystyrene or a copolymer of styrene and acrylonitrile and a liquid barrier layer, which is a copolymer of at least 50 wt. ^ I nitrile monomers formula CH ₂ = C 0Ή, I X wherein X is hydrogen, halogen or a lower alkyl group -29- 309881/0984 with up to 4 carbon atoms, forms, with the formation takes place by means of blow molding and biaxial orientation. 11. Packaging method for beverages, which make it necessary to maintain the gas pressure in the container, characterized in that a container according to claim 9 normally fills and seals. 309881/0984 Blank page