SE468381B - MULTI-LAYER STRAIGHT POLYESTER BOTTLE AND PROCEDURES FOR PRODUCING THEREOF - Google Patents

Description

468 581 10 15 20 025 30 35 40 IXJ Summary In the manufacturing process of the stretched multilayer the polyester bottle with a base layer of a polyester and a barrier layer of an ethylene vinyl alcohol copolymer, comprising providing of a coextruded tube, cut-off thereof, melt-formed of its lower part and biaxial blow molding in the now mentioned order, a multilayer stretched polyester bottle can be provided with good coating properties, barrier layer properties for gases as well as molecular orientation. The invention further relates to improvements in this regard.

In particular, the invention relates to a multilayer stretched polymer. ester bottle comprising a neck portion with an orifice at its upper end and provided with a screw or ledge along the edge of the estuary, a lower part formed by melting a joint tubular part and a main part oriented molecularly in biaxial led by stretch blowing of the pipe part, whereby pipe material consists of a coextruded with internal and external layer of a polyester based on ethylene terephthalate units and an intermediate layer of an ethylene vinyl alcohol copolymer with an ethylene content of less than 50 mole percent.

In addition, the method mainly relates to the achievement of a method of making a multilayer polyester bottle comprising providing a multilayer tube by co-extrusion which tube comprises an ethylene vinyl alcohol copolymer with an ethylene content lower than 50 mol% in the form of an intermediate layer for the barrier layer-forming effect against gases, a inner and outer base layers of a polyester and, if required, an adhesive layer applied between the two resin layers, shortening the pipe to the desired length, closing one end of the cut pipe by melt joining so that a bottom part is formed, forming the other end of the shortened tube to a neck portion with an orifice at its upper possibly genome clamping screw closable end, preheating it thereby obtained preformed material at a stretching temperature about 85 to TZOOC as well as the practice of blow molding stretching biaxially in the axial and peripheral direction with a blow mold tools.

Detailed description of the drawings Fig. 1 shows in section a multilayer pipe according to the invention.

Pig. 2 and 5 show in section a preformed material in which 10 15 20 25 30 35 40 - 468 3-81 a lower part and a neck part are formed.

Figs. 4 and 5 show sections of a preformed material held in a blow molding tool before the respective after blow molding.

Pig. 6 shows the production of a multilayer stretched bottle according to the invention.

Detailed description of preferred embodiments In accordance with what has been mentioned above, the invention is primarily intended for the improvement of the layer properties against gases for a through a stretch bottle, wherein an ethylene vinyl alcohol copolymer with an ethylene unit content of less than 50 mol% will be used, possibly in combination with others kinds of vinyl alcohol polymers.

As is well known, the thermoplastic nature of polyvinyl alcohol can improved by modification, whereby ethylene vinyl alcohol the thermoplastic nature of the copolymer increases with increasing content food units. With increasing content of ethylene units, the polymer is reduced melting point to a corresponding degree. Then the ethylene vinyl alcohol copolymer and the polyester resin as described below is stretched under the same conditions, it will be appreciated that ethylene vinyl alcohol copolymers more with lower melting temperature and extensibility temperature to be used. According to the present invention, however, time an ethylene vinyl alcohol copolymer with a higher melting temperature and extensibility temperature for use. ' At a content of ethylene units exceeding 50 mol%, it is reduced first, the melting temperature, why simultaneous stretching can be successfully carried out with the polyester resin, however cost of quality in gas barrier layer properties and laminability.

Secondly, the process also results in ethylene vinyl alcohol polymers with a high content of vinyl alcohol units extensibility of multilayer materials incorporating polyester resin underneath for ester resin suitable temperature conditions. An ethylene vinyl alcohol copolymer with a content of ethylene units lower than 50 molar cent, i.e. a high content with respect to vinyl alcohol units, can therefore be used as the appropriate ethylene nyl alcohol copolymer in laminating a polyester resin.

As a starting material for blow molding stretching of plastic for example, polyesters, it is known to form a bottom provided preformed material of the polyester by injection molding 4-68 581 ^ 10 15 20 and this preformed material is stretched during blowing as well axial stretching by means of a tension rod, and also a procedure is known comprising stretching to a tubular joint. targets, which are fixed in a holder and stretched axially, wherein a fluid is blown in to provide stretching through the blowing.

Apply these procedures to multilayer materials with a polyester layer and an ethylene vinyl alcohol copolymer layer, serious consequences can be caused in terms of extensibility and the durability of the lamination.

First of all, according to the invention, a temperature, for example, exceeding 140 ° C, that the polyester rapidly crystallizes sera with obstructed stretching as a result; the polyester becomes white colored, so that the prepared container becomes opaque. In order to produce a multilayer preformed material by injection molding the polyester must be sprayed followed by spraying of ethylene the vinyl alcohol copolymer on the injection molded and preformed the polyester material. Because it is necessary to regulate the temperature of the preformed polyester material to a temperature value significantly lower than the above-mentioned critical temperature luck, the heat adhesion for both plastics is insufficient. in the inner surface, why delamination is caused, or also material breakage occurs in the corresponding coated parts.

In addition, the extensibility, especially of the ethylene vinyl alcohol copolymer biaxial extensibility less good at the extensibility suitable for polyesters temperatures, i.e. then a coextruded multilayer pipe material of a polyester layer and an ethylene vinyl alcohol copolymer layer attached to a holding device is stretched in the axial direction, emerges significantly visible and latent cracking during subsequent stretching blowing. A phenomenon similar fibrillation is believed to be caused in the ethylene vinyl alcohol copolymer layer when stretching in the axial direction, which is why the stretch marks or cracks occur the subsequent blowing.

The invention is characterized first and foremost by a polyester and an ethylene vinyl alcohol copolymer are coextruded to a pipe. This co-extrusion is carried out by joining a molten polyester and a molten ethylene vinyl alcohol copolymer into a preformed material and extruded them through a linear nozzle. Because both plastics are fused together form during a certain contact time, good matcrial mixture occurs at the interface of each plastic, and the degree of adhesion heat is much better than in the case of multilayered 10 15 20 25 30 35 40 5 __ 468 381 haggling. This result is achieved in a similar way even then one adhesive resin material is applied between the polyester and ethylene the vinyl alcohol copolymer.

The invention is also characterized in that it is coextruded the multilayer tube is shortened to a certain length and to unite the end is closed by melt connection to provide a bottomed part. When the bottomed preformed material material is produced, it is possible to carry out blowing of the material substantially simultaneously with axial stretching by inserting a tension rod into the preheated and 7 preformed the material. About this stretching procedure in one steps used, the emergence of the visible and latent cracking car traffic is prevented, which can often be caused by a corresponding multi-step procedure.

In the process according to the invention a saponified one is used copolymer of ethylene and a vinyl ester such as vinyl acetate in the form of an ethylene vinyl alcohol copolymer. With respect to shaping the process and the gas barrier layer properties are suitably stated the ethyl ether content of ethylene vinyl alcohol copolymer to between 15 and 50 mole percent, preferably 25 to 45 mole percent at a degree of saponification of at least 96 percent. The molecular weight of the copolymer is not of major importance, provided that the copolymer has educational ability.

Polyethylene or a copolyester with a predominant ethylene terephthalate units and a small amount of others ester units can be used. The molecular weight of the polyester is smaller importance, provided that the polyester has film-forming ability.

To improve the adhesion between the polyester layer and the layer of ethylene vinyl alcohol copolymers, whichever preferably known suitable binder can be used, for example copolymers ester of etherified kind, epoxy-modified thermoplastic resin and acid-modified thermoplastic resin.

Different laminate structures can be used based on from a base layer of polyester (PET), a layer of ethylene vinyl alcohol copolymer (EVAC) and an adhesive layer (AD). As Possible examples include PET / EVAC / PET, PET / EVAC + AD / PET and PET / AD / EVAC / AD / PET in that order based on the inner surface.

The respective layer thickness can vary within a wide range intervals, but it is preferred that the relationship between 468 581 tive layer thickness for PET / EVAC is within the range 2/1 to 30/1, especially 4/1 to 15/1. Then the adhesive layer used, a layer thickness ratio for PET / AD is preferred within the range 5/1 to 100/1, especially 10/1 to 50/1. Figure 1 shows a preferred embodiment of a pipe member. multilayer material according to the invention. This pipe material in several layers comprise inner and outer layers 2 and 3 of poly- ester, an intermediate barrier layer for gases 4 of an ethylene- vinyl alcohol copolymer and applied intermediate adhesives 10 tooth layers Sa and Sb.

As previously mentioned, it is important that the pipe material produced by coextrusion. For the prevention of crystalline polymerization of the polyester, it is important that it extruded the pipe material is cured, for example by immersion in water. Thus, if the extruded multilayer tube is cured, the outer polyester layer is easily held in place its amorphous state, the density being within the range of between 1,331 and 1,339 g / cm3 (measured with an n-heptane / carbon tetrachloride-based density gradient column of ZOOC). Emeller- 20 time, the polyester on the inner wall of the tube will have a temperature higher than the outer polyester material due to the stand to the cooled outer surface. Ethyl vinyl alcohol copolymer even in the molten state, the merisate has a thermal conductivity about 1/2 or 1/4 of the polyester. Thanks to these features The ethylene vinyl alcohol copolymer will act as a heating agent. insulating layer for the laminated pipe during its cooling to solid form. For that reason comes the inner polyester layer to maintain a high temperature for a longer period of time and crystallization of the ester proceeds in the f) While the density increases to a level of about 1.355 g / cm

As a result, the inner polyester layer becomes white, through the appearance is lost, and stretching of the objected surface the layer is made more difficult. The invention accelerates polyester materials. cooling of the material by the passage of a cooling medium through the The density tube, whereby the density of the finished multilayer the material can be adjusted to a level corresponding to or up to 0.015 g / cmš higher than the density of the polyester at outer surface, thereby whitewashing the inner polyester surface is prevented, while the extensibility of the inner poly- 40 ester layers are improved. 10 '15 20 25 30 40 7 468 381 The pipe material is shortened to the desired length and one end of the truncated tube material is heated and melted and formed. pressed in a form made up of male and female parts that correspond to desired design of the bottom section, for example a hemispherical one shape, corresponding to the bottom portion 6 according to figure 2.

Then the other end of the pipe material is heated 1 and subjected to pressing, stretching and blow molding in forming tool, thereby obtaining a preformed material 10 with a mouth 7 in its upper end which is provided with a screw fastening or fastening device, such as a thread 8 or a ledge along the periphery of Fig. 5.

The order of the various sub-steps in production of the aforementioned preformed material is not critical, that is say the various steps can be performed in the order now mentioned or conversely.

In addition, according to the aforementioned methodology, the amount of plastic, which must be discarded at the time of manufacture, lower.

At subsequent steps, the preformed material is heated. through hot air, infrared heating or high-frequency electrical heating by induction to a for stretching of the preform made the multilayer material the appropriate temperature, ie the pre- made the material is heated to a stretching temperature for the polyester resin, usually between 85 and 120 ° C, preferably 95 to 110 ° C.

According to Figs. 4 and S, where the stretch blow molding illustrated, a casting core 11 is placed in the mouth thereof preformed material 10, and the mouth is fixed with two mold halves 1Za and 12b. A vertically movable stretching rod 13 is mounted in the middle of the casting core 11 and a ring shaped gap 14 for the blowing is arranged between the stretching the rod 13 and the casting core 11.

According to the invention, the outer part 15 of the stretching ningsstaven 13 affixed \ üd.bottendelens invändiga yta 6 av the preformed material 10, and the stretching bar 13 is passed downwards, the preformed material 10 being stretched in axial led. A fluid is simultaneously blown into the preformed material Through the gap 14, whereby the preformed material expands and is stretched peripherally by the pressure in the fluid.

According to the production procedure, it is possible to perform stretching in the axial and peripheral direction substantially 468 381 10 15 20 25 30 40 simultaneously, with even layers of ethylene vinyl alcohol copolymers with a high content of vinyl alcohol units can be stretched at a comparatively low temperature.

This result is completely unexpected considering that stretching of an ethylene vinyl alcohol copolymer is associated with great difficulty, and even if a film of this copolymer stretched in several steps biaxially at the appropriate temperature for this, the aforementioned ruptures occur in the material.

In addition, the ethylene vinyl alcohol copolymer in the multilayer the structure is only stretched at a relatively high temperature if 140 to 165 ° C at the blow molding stretch of the multilayer the tubular material of a polypropylene layer and an ethylene vinyl alcohol copolymer layer. It can therefore be considered completely unexpected, that the ethylene vinyl alcohol copolymer of the invention can be stretched biaxially at the stretching temperature of the polyester, i.e. between 85 and 120 ° C, especially 95 to 110 ° C.

This is probably due to the fact that co-extrusion is carried out in such a way that the layer of ethylene vinyl alcohol copolymer is applied applied to the polyester layer, while the delamination is prevented at a simultaneous biaxial stretch.

This provides a stretched polyester bottle 16 with several layers, as shown in Fig. 6. At the stretched of several layered bottle according to the invention, the layers are molecular oriented, so that the density of the polyester layer corresponding to the external surface is at least 1.345 g / cms, preferably at least 1.348 g / cmš, similar to one in the usual way stretched polyester bottle.

According to the invention, the polyester bottle is external and internal surfaces are molecularly oriented, the inner surface being at least 1.345 g / cm 2, preferably at least 1.348 g / cm 2.

In addition, the bottle is characterized in that also ethylene vinyl alcohol the hollow copolymer in the intermediate layer is biaxial molecularly oriented so that the orientation coefficient 05) i axial joint and the coefficient of orientation (m) in the peripheral joint determined by polarized fluoremetry, meets the following condition: the value of {+ m is at least 0.2, preferably at least 0.3, and the value of | {”- ml is less than 0,1, preferably vis 0.07.

The two-dimensional orientation of the vessel wall (orientation tering in the plane of the vessel wall) can be determined according to the aforementioned 10 15 20 25 30 35 9 468 381 polarized fluoremetry.

As shown by, for example, Yasunoru Nishijima, Polymers, f15, No. 175, page 868 (Japanese Polymer Association 1966) kan_ the two-dimensional coefficient of orientation is determined according to a method, in which the degree or nature of molecular orientation for thermoplastic resin, such as a polymer at solid deformation or by liquid formation of a solution or melt is determined quantitatively or qualitatively by the use of optical anisotropy for a fluorescent polymer.

About the two-dimensional orientation in the vessel wall to a stretched container according to the present invention is considered taking into account what is taught by the aforementioned technical report, the two-dimensional orientation can be quantitative expressed according to the following formula: msin4Q; + å n) IHÉU) = Queue (fcosñv + wherein Inüu) refers to the intensity of the polarized component at the fluorescence of the thermoplastic system, H states that the direction of vibration of the incident polarized light is parallel to the direction of the measured polarized light, OJ denotes the direction of rotation of the sample in relation to fluorescence vibration direction, K refers to the maximum the probability of excitation when the molecular axis of the sample is parallel to the direction of vibration of the excited fluorescent cence, ø denotes the molecular fluorescence contraction, ¿Nw corresponds to the proportion of the molecular orientation in axial direction in the vessel wall plane of the finished container, m corresponds to the proportion of molecular orientation in the rectangular direction in relation to the axial direction (ie the peripheral) direction), n refers to the proportion of non-oriented share in the plane, and - @ + m + n is 1.

The above value for {7+ m means that ethylene vinyl alcohol the copolymer is efficiently molecularly oriented biaxially.

Due to this in-plane molecular orientation, the bottle is the invention has been improved with respect to the barrier layer properties for oxygen and transparency, compared to a bottle containing ethylene the vinyl alcohol copolymer is not oriented.

The absolute value of the difference between the value of I-6 - m f, has a relationship to the molecular orientation Å and m, ie axial and peripheral direction in ethylene / vinyl 11-68 10 15 20 25 30 35 40 10 381 the copolymers.

In the vessel of the invention, the molecular orientation is the ring in the axial direction well balanced against the molecular one the orientation in the peripheral direction, where the value of l {-: ni is less than 0.1.

According to the invention, a bottle is provided in which the intermediate the lying layer in the main part of the bottle corresponds to a value for ¿+ m 0.1, i.e. by the formation of a tube by coextruding of at least 0.2 while the value of LÉ-n fl is less than inner and outer layers of polyethylene terephthalate and an intermediate layer of an ethylene vinyl alcohol copolymer, it has been made possible to perform blow molding stretch so that a value for {7+ m amounts to at least 2 and by stretching it preformed material in substantially simultaneous peripheral direction axial extension, it has been made possible to maintain the balance in orientation Lä - ml below 0.1, each in the occurrence of cracks and fissures and minor holes can be avoided folded into the ethylene vinyl alcohol copolymer.

By a biaxial stretch blowing process in several steps, in which a multilayer tubular material is stretched in the axial direction, the value of the orientation coefficient increases ({) in the axial direction, while the value of the orientation coefficient either (m) in the peripheral direction clearly decreases and results in reducing impact strength and oxygen permeability.

According to the invention, the intermediate is also oriented the layer of ethylene vinyl alcohol copolymer molecularly in a balanced manner ratio in the axial and peripheral direction, and oxygen the permeability coefficient is maintained at a very low level while also improving transparency.

According to a further feature of the invention, polyethylene terephthalate was inverted as the outer surface of the bottle or the tubular material for its production, while a copolymer ester, containing a predominant amount of ethylene terephthalate units and which has a lower crystallization rate than ethylene terephthalate, was used for the interior surface.

This design addresses the above-mentioned shortcomings heat transfer, which is caused by an ethylene vinyl alcohol copolymer with good barrier layer properties for gases was used as an intermediate layer in the multi-layer built polyester bottle, ie by using instead of the usual k! 10 15 20 25 35 40 468 381 11 polyethylene terephthalate (PET) uses a lower copolyester crystallization rate than for the corresponding PET-based layers, crystallization of the resin in the inner resin the layer caused by the forming step is largely prevented as far as possible, while the adaptation of the internal resin the tensioning torque bearing improves the transparency of the bottle and in addition, additional material properties can be improved upon the tensile moment.

Known types of polyethylene terephthalate can be used, and a basic conditions are their film-making ability. Polyethylene terephthalate with an intrinsic viscosity of at least 0.8, especially 1.0, can preferably be used.

A copolyester consisting essentially of ethylene terephthalate lat units, which contain ester units in which at least either the acid or alcohol component is an acid other than terephthalic acid or an alcohol other than ethylene glycol can be used for the construction of the polyester layer of the inner layer resin. Because this copolyester is essentially made up of ethylene terephthalate units, the copolyester can be stretched through blow molding under the same conditions as when PET forms the exterior the layer and also the inner layer will be oriented in this case molecularly in the biaxial direction. In addition, one can be beneficial effective reduction of the crystallization rate it is achieved for PET, thanks to the fact that the polyester contains ester units of a different structure from ethylene terephthalate the devices.

The reason why different polyesters were used for the exterior and the inner layer according to the invention consists in that because the polyethylene terephthalate for the outer layer is rapidly cooled by the external cooling according to the aforesaid reasoning and the resin layer is cured, the crystallization will be inhibited also in the polyethylene terephthalate whose crystallization time is short while maintaining transparency, while the copolyester for the inner layer on the inner side of the intermediate the layer does not crystallize due to long crystallization time even if the cooling rate is low, why transparency is maintained.

In the copolyester, according to the invention, in addition to the acid components other than terephthalic acid include isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, 2,2-his (4-carboxylic acid 12 4-68 381 OUT 10 15 20 25 30 40 oxyphenyl) propane, bis (4-carboxyphenyl) methane, cyclohexane dicarbyl oxylic acid (hexahydroterephthalic acid and hexahydroisophthalic acid), adipic acid, sebacic acid, succinic acid and dodecane-dicarboxylic acid acid. As alcohol components other than ethylene glycol, propylene glycol, butanediol, neopentyl glycol, hexanediol, glycerol, diethylene glycol, triethylene glycol, tetraethylene glycol, dibutylene glycol and tributylene glycol.These acid components and / or or alcohol components may be used singly or in admixture two or more.

Preferred examples of copolyesters can be mentioned polyethylene terephthalate / isophthalate, polyethylene terephthalate / adipate, polyethylene / butylene terephthalate, polyethylene / butylene terephthalate / in sof tal at, polyethylene / neopentylene terephthalate and polyethylene / neo- pentylene terephthalate / isophthalate. Copolyesters that can be used according to the invention, however, are not limited to those now listed example.

Preferably, the copolyester of the invention should contain ethylene terephthalate units in an amount of 85 to 96 molar cents, especially 90 to 94 mole percent, where the remainder consists of other ester units. Of course, that is implied that the copolyester should have a molecular weight that allows film properties.

In the design of the present invention, given, that the outer PET layer / inner copolyester layer thickness ratio is in the range 1/1 to 5/1, preferably 2/1 to 3/1. In doing so, it must not be overlooked that The present invention encompasses the eventuality of the exterior the layer increases in thickness and the thickness of the inner layer decreases, whereby cooling of the inner layer is further To advantage.

The bottle according to the invention has, in addition to high transparency, significantly improved barrier layer properties than other plastics bottles or flasks, consisting solely of polyesters (stretched PET bottle). In addition, the barrier layer properties of gases may be regulated, and the bottle also has a high firmness to pressure. Therefore, the storage life of carbonated beverages such as beer, cola and cider are improved. Its- except that the bottle is excellent from an environmental point of view because its production only produces harmless gas in the form of coal oxide and water vapor. For this reason, the bottle is excellent at u 10 15 20 25 30 JU 468 381 13 destruction by incineration. In addition, the bottle offers a The present invention provides comparable advantages to a gas bottle in terms of transparency, barrier layer properties for gases and pressure resistance in combination with low weight and high resistance resistance to breakage.

The invention will now be described in more detail with reference to to the following examples, which are not intended in any respect to constitute a limitation of possible embodiments.

Example 1. By using extruder devices for the inner ones and outer layers, which are provided with a complete screw with diameters meter 65 mm and an effective length of 1430 mm, extruder intermediate layers and adhesive layers that are fitted with a complete screw with a diameter of 50 mm and an tive length of 1100 mm and an annular nozzle for five layer, a three-component tubular laminate was extruded with inner and outer layer of polyethylene terephthalate (PET) with an intrinsic viscosity 1.0, an intermediate layer of an ethylene vinyl alcohol copolymer (EVAC) with a vinyl alcohol content of 70 molar cents and in between applied adhesive layers of modified high density polyethylene grafted with maleic anhydride in 10,000 ppm epoxidized octyl oleate had been incorporated into from the nozzle to cool the tube nitrogen gas was blown inside the gendm tube part. This tube had an outer diameter meters of 22 mm and the thickness of the inner layer, the outer layer, the adhesive layer and the intermediate layer were respectively 1.4 mm, 2.0 mm, 0.05 mm and 0.5 mm. The tube was shortened to desired size (length was 129 mm and weight 55 g). One end of the tube was heated to ZZOC and sealed by melting to give coming from a hemispherical bottom. The other end of the tube is heated. to 150 ° C to initiate crystallization in the neck portion and an annular ledge is provided on the neck portion, thereby providing held a preformed material with a total height of 148 mm.

The preform was heated to 105 ° C and that preformed material was exposed mainly simultaneously biaxial stretch blow molding in a blow molding tool by stretching the preformed material at stretching ratio of 1.0 in the longitudinal direction and stretch blowing of the preformed material at a stretching ratio of which water externally and simultaneously to cool its interior of 30 mm and an inner diameter 3.0 in the lateral direction, with a multilayer stretched bottle with 10 -15 ZO 25 35 40 14 an internal volume of 1550 cms was prepared.

At the main body of the bottle, the density of PET was at that the layer 1.355 g / cmà and the density of PET at the inner layer outer was 1.365 g / cm °, and in intermediate EVAC layers the and 0.38. Bottle Z4 hours.atm the ring coefficients {and m and 0.34, respectively the acid permeability of the can was about 1.5 cm3 / m2- (37OC), and the bottle had excellent transparency. concrete floor from a After dropping height of 120 cm no delamination was caused. After- of the bottle on one the bottle was intact and as the neck portion of this bottle was crystallized in significant extent, no deformation of the neck part also occurred after filling with a liquid with a temperature of 93OC and closure of the bottle.

Example 2. extruded a two-component three-layer laminate with an inner and an outer layer of polyethylene terephthalate with an intrinsic viscosity 0.9 and an intermediate layer of an ethylene vinyl alcohol copolymer (EVAC) with a vinyl alcohol content of 58 mol% Using the same apparatus as in Example 1, through water for cooling the outer part of the pipe, and at the same time air was blown inside to cool its inner part. The pipe had an outer diameter of 22 mm and an inner diameter of 16 mm.

The thickness of the outer layer, the inner layer and the intermediate The layers were 1.6 mm, 1.2 mm and 0.2 mm, respectively. The pipe shortened to the desired size (length was 85 mm and the weight to 20 g). One end of the tube was heated to about 230 ° C and sealed by melting to give a spherical bottom. To prevent crystallization in the neck part the other end of the part was initially heated at 110 ° C, and a threaded portion and an annular neck ledge are provided for the formation of a preformed material.

The preform was heated to 100 ° C and precipitated. was set for a substantially biaxial stretch blow molding at one stretch ratio of 1.8 in the longitudinal direction and a stretch 215 in the lateral direction, whereby a stretched bottle in several layers with an internal volume of 500 cms was obtained.

In the main part of the bottle, the density of PET was at the outside layer 1.352 g / cmš while the density of the inner layer was 1.357 g / cmš, and the orientation coefficients <5 and m for EVAC were 0.31 and 0.35, respectively. The acid permeability of the flask ..- O .- "'7 was 2.0 cm) / m "'34 h-atm (3. L). When the bottle was dropped on 10 15 20 25 40 ¿5 4es 381 concrete floor from a height of 120 cm did not occur anything breakage.

Example 3. in the same manner as in Example 1, except that only A 3-component 5-layer tube laminate was prepared the outside was cooled. _ The tube was subjected to a substantially simultaneous biaxial stretch blow molding under the same conditions as included in Example 1, to provide a multilayer stretched bottle with an internal volume of 1550 cms.

The inner layer of the bottle was white and opaque and the bottle had slightly worse transparency than the bottle according to Example 1.

Example 4. A tubular laminate and a preformed material under the same conditions as in Example 1. the material was heated to IOSOC, and stretched at one tensile ratio of 1.7 in the longitudinal direction. Hereafter the preform was stretched at a stretching ratio 3.0 in the lateral direction in a blow molding tool. One multilayer stretched bottle with an internal volume of 1550 cm was obtained by this subsequent stretch blow molding.

Cracks formed in the intermediate EVAC layer, and the oxygen permeability of the bottle was 3.1 cm 3 / m2-24 h.atm (37 ° C) and the appearance was not comparable to the bottle of Example 1.

Example 5. By using extruders for those outer and inner layers provided with a complete screw with a diameter of 65 mm and an effective length of 1430 mm, extruders for an intermediate layer and widening adhesive layers, which are provided with a complete screw with a diameter of 50 mm and an effective length of 1100 mm and one annular die for five layers was co-extruded into a 4- 5-layer tubular laminate comprising an outer layer of polyethylene terephthalate (PET) with an intrinsic viscosity of 1.0, an inner layer of an ethylene terephthalate copolymer having a isophthalic acid content of 8 mole percent and an intrinsic viscosity of 1.1, an intermediate layer of an ethylene vinyl alcohol copolymer (EVAC) with a content of vinyl alcohol copolymer units of 70 mol percent and adhesive layer of a polyester ether copolymer applied between the inner and outer layers and the intermediate the layer in a water-cooled tank from the multilayer nozzle.

The tube had an outer diameter of 50.0 mm and a thickness of 468 10 15 20 125 35 16 381 3.8 mm, and the thickness ratio of the outer layer / width adhesive layer / intermediate layer / adhesive layer / the inner layer was 100/5/15/5/40. The lower part of it is The transparent tube material was sealed by melting to form a hemispherical bottom and the upper part of the pipe material were formed g as a threaded neck part. The preformed material thus obtained was heated first at 98 ° C and first exposed to simultaneous biaxial stretch blow molding at a stretch longitudinal ratio of 1.9 in the longitudinal direction and a ratio of 3.0 in the lateral direction to obtain a multi- layer stretched polyester bottle with an internal volume of 1550 cms.

The density of PET amounted to the majority of this obtained the bottle to 1,360 g / cms and the orientation coefficient The values for EVAC were 0.32 and 0.35, respectively. Ljusdif- the fusion for the body of the bottle was 10 to 12. When the bottle was lowered was dropped on a concrete floor from a height of 120 cm occurred no breakage. The acid permeability of the bottle was 1.7 cms / m2 -24 h.atm measured at 37 ° C at a relative humidity inside the bottle can about 100 percent and 20 percent on its outside. Acid permeabi- the size of a bottle consisting only of polyethylene terephthalate with the same weight and shape as the aforementioned was 9.8 cms / m2 -24 h.atm, ie the oxygen permeability of a bottle according to the finding was about 1/5 of the oxygen permeability of a bottle consisting exclusively of PET.

Example 6. was extruded in water with a 4-component 5-layer tube laminate an outer layer of polyethylene terephthalate (PET) with a boundary viscosity of 0.9, an inner layer of an ethylene terephthalate composition Using the same apparatus as in Example 5 polymer with an isophthalic acid content of 8 mol% and a limit viscosity of 1.1, an intermediate layer of an ethylene vinyl alcohol copolymer (EVAC) with a content units of vinyl alcohol of 70 mole percent and an adhesive layer of modified density polyethylene grafted with maleic anhydride, in which 10,000 ppm of epoxidized octyl oleate had been incorporated, the material from the nozzle was kept cooled. The pipe material had an outer diameter of 30 mm and an inner diameter of 22 mm, and 40 the thickness of the inner layer, the outer layer, the adhesive layer and the intermediate layer were 1.4 mm, 3.0 mm, respectively, 0.05 mm and 0.5 mm. The tube material was shortened to the desired size. play (length was 129 mm and weight was 55 g), and one end 10 15 20 10 17 4es 381 of the pipe material was heated to about ZZOOC and sealed by melting to form a hemispherical bottom portion. Pipe- the other end of the material was heated to 1SOOC for starting of crystallization in the neck part and a threaded part and a ring shaped ledge is provided at the neck portion to obtain a preformed material with a total height of 148 mm.

The preform was heated to 105 ° C and was set for a substantially simultaneous biaxial stretching blowing by stretching the preformed material into one I 1.9 in the longitudinal direction and the preformed material in a stretch lateral direction, whereby one was obtained stretching ratio if blow molding of it 3.0 ratio of 3.0 i multilayer stretched bottle with an internal volume of 1550 cms.

The density of PET was 1.355 g / cm 3 at the bottle main part, and the orientation coefficients -5 and m amounted to for EVAC to 0.34 and 0.38, respectively. The light diffusion of the bottle was 9 and the oxygen permeability was about 1.5 cm 3 / m2-24 h.atm (37OC). No breakage or delamination occurred when the bottle can be dropped on a concrete floor from a height of 120 cm.

Since the neck portion of the bottle was substantially crystallized did not hit any deformation when the bottle was filled with one liquid at 93 ° C and sealed.

Example 7. A 4-component pipe material in 5 layers with an outer layer of polyethylene terephthalate (PET) with an intrinsic viscosity of 1.0 and an intermediate layer of an ethylene terephthalate copolymer more (Kodar PETG5 763), in which part of the glycol component is was made of 1,4-cyclohexane-dimethanol and an intermediate layer of an ethylene vinyl alcohol copolymer (EVAC) with a vinyl alcohol content of 70 mol% and adhesive layers of maleic acid anhydride-grafted polyethylene (maleic acid content was 0.8 weight percent) applied between the outer and the intermediate layer, and between the inner and intermediate layers extruded were cooled and cooled in water using the same apparatus as in Example 5. _ The tube had an outer diameter of 22 mm and an inner diameter about 16 mm and the thickness of the outer layer, the inner layer and the intermediate layer was 1.6 mm and 1.2 mm, respectively and 0.2 mm. The pipe material was shortened to the desired size (length it amounted to 85 mm and the weight was 20 g). One of the pipe material end was heated to about 2300 C and sealed by melting f seen neck portion is provided to obtain a preformed material. 10 15 is 3 'l e- to provide a hemispherical bottom. To prevent CO crystallization in the neck portion was heated the other end first to a temperature of about 10 ° C and a threaded and ledge The preform was heated to 100 DEG C. and evaporated. was set for substantially simultaneous biaxial stretch blow molding at a stretching ratio of 1.8 in the longitudinal direction and a stretch ratio of 255 in the lateral direction to obtain landing of a multilayer stretched bottle with an internal volume of 500 cms. In the main part of the bottle, the density of PET was 1,353 g / cm3 and the coefficients of orientation «foch m for EVAC amounted to 0.32 and 0.33, respectively. Plasma light diffusion amounted to 8 and the oxygen permeability was 2.0 cm 2 / m2 ° 24 h.atm (37OC). If the bottle was dropped on a concrete floor from a height about 120 cm no breakage occurred.

Claims (7)

10 15 20 -25 30 35 40/7 468 381 Claim 1. A multilayer stretched polyester bottle - characterized by a neck portion with a mouth, provided at its upper end with a thread or ledge along the periphery, a bottom portion made by melt joining and closing a tubular material and having a main portion in the vacuum suction joint. biaxially molecularly oriented in the longitudinal and lateral directions by stretch blowing the tubular material, the tubular material being composed of a coextruded inner and outer surface primer layer of a polyester, consisting essentially of ethylene terephthalate units and an intermediate layer of an ethylene-ethylene polymer with an ethylene vinyl alcohol units less than 50 mole percent, with adhesive material applied between polyester layers and copolymer layers and the inner and outer surface base layers of polyester being biaxially molecularly oriented so that the density (20 ° C) at the middle part of the main portion of the bottle for each inner and outer surface base layer is at least 1.345 g / cm 3, and the intermediate layer of an ethylene vinyl alcohol copolymer is biaxially molecularly oriented so that the coefficient of orientation (E) in the longitudinal direction of the bottle and the coefficient of orientation (m) in the peripheral direction of the bottle are individually determined by polarized fluorometry, satisfying the condition that 2 + m is greater 0.2 and the value [Z - m | is less than 0.1. A multilayer stretched polyester bottle according to claim 1, characterized in that the outer surface primer layer comprises polyethylene terephthalate and that the inner surface primer layer comprises a copolymer with ethylene terephthalate units which has a lower crystallization rate than polyethylene terephthalate. in A multilayer stretched polyester bottle according to claim 2, characterized in that the copolyester comprises 85 to 96 mol% of ethylene terephthalate units, the remainder being ester units other than ethylene terephthalate units. A process for producing a multilayer polyester bottle comprising molding by co-extrusion into a multilayer tubular material characterized by the use of an ethylene vinyl alcohol copolymer having an ethylene unit content of less than SO mole percent as an intermediate layer acting as a resin barrier layer for gases and a polyester resin h% V "dS“ k1i9e “Öeåïåe fl de HV Gtylene tereitalate units as inner 30 35 40 46 trunk” w and outer surface primer layer as well as applying an adhesive layer between the two resin layers, shortening the pipe material to a predetermined length, one end of the tube and pressing the heated end of the cut tube with concave and convex shapes with cavities and corresponding to the design of the bottom so that by melting one end of the cut tube a bottom part is obtained, forming the other end of the shortened tube material to a neck portion with an orifice at its upper end and provided with a thread or ledge l meadow periphery, preheating the thus obtained preformed material to a stretching temperature of 85 to 120 ° C and treating the preformed material by biaxial stretching blow molding in the longitudinal direction almost simultaneously with the peripheral direction in a blow molding tool. Process according to Claim 4, characterized in that the outer surface of the outer polyester layer has a density (20 ° C) of 1.331 to 1.339 g / cm 3 and the inner surface of the inner polyester layer has a density (20 ° C) equal to or exceeding the density of the outer surface of the outer polyester layer by up to 0.015 g / cm3. 6. A method according to claim 4, characterized in that a stretching rod exerts pressure at the bottom part of the preheated preformed material, wherein the preformed material is stretched in the axial direction and that stretching blow molding of the preformed material is carried out substantially at the same time as the said stretch in the axial direction. Process for the production of a multilayer polyester bottle according to Claims 4 to 6, characterized in that a multilayer tube is produced by co-extrusion on the basis of an ethylene-vinyl alcohol copolymer with an ethylene content of less than 50 mol% in the form of an intermediate layer which acts as a resin barrier layer for gases and a polyester resin as inner and outer base layers and that an adhesive layer is incorporated between the two resin layers, the outer polyester resin layer of the coextruded tube being cooled by immersion in water and vigorous cooling of the inner polyester resin layer thereby that a cold medium is allowed to flow through the co-extruded tube internally, the tube is cut 10 W 463 381 to a predetermined length, one end of the cut tube is closed by melt joining so that a bottom part is obtained, the other end of the cut tube is formed into a neck portion end and provided with ledge or thread along the periphery, the preform thus obtained is preheated at the stretching temperature 85 to 120 ° and the preform is subjected to stretch blow molding biaxially in the axial direction and peripheral direction in a blow molding tool.