DE2358153A1 - MULTI-LAYERED HOLLOW BODY, METHOD FOR MANUFACTURING A MULTI-LAYERED HOLLOW BODY AND MULTI-LAYERED PLATE-SHAPED MATERIAL - Google Patents

Description

Or. E Wiegand, D! P! .-! Ng. W. Nismsnn Dr.-Bj. Kefckr. Dip! .Ir.-. C. rainha

Hamburg £ 0 - KenlgstraSa 28

W.26 095/73 20 / Hh

Emery I. Valyi New York (V.St.A.)

Multilayer hollow body, process for the production of a multilayer hollow body as well as multilayer sheet material.

The invention relates to multilayer materials, in particular containers or hollow bodies, the properties that cannot be obtained by a single layer product.

^& Multi-layer plastic containers are highly desirable whenever it is difficult to meet all requirements and regulations by using a single plastic ..

For example, the low cost, the easy deformability, the good impact resistance and

40982Λ / 0739

- 2 - O T Γ Ί 1 ~ Λ ■ ·

I ο - "ι ■ j 1 ο 3 ι

other desirable properties of polystyrene, PVC ^and: the poly-olefins, particularly polyethylene, lead to highly desirable containers for many purposes, however, such as polyethylene does not have sufficient barrier or Lösungsiflittelwiderstand for many applications.

In cases of this nature, attempts have been made to provide an enveloped container in which the container wall consists of more than one substance in order to achieve properties that cannot be achieved by a single plastic owns. j

However, the economical production of such containers or hollow bodies has so far been extremely difficult, so difficult that an economical production was hardly possible. In addition, certain combinations of properties resulted considerable difficulty even in a composite container.

For example, it is highly desirable to have a hollow body that has resistance to has elevated temperatures, for example above 79 ° C (175 ° F) and preferably above 104 ° C (220 F) while at the same time there is increased resistance to a flowable medium, for example a gas barrier resistance or a resistance to deia passage of oxygen or carbon dioxide or a solvent. In the production of composite or multilayer hollow bodies of the aforementioned type however, it is known that when the container is exposed to elevated temperature conditions, for example when it is filled with substances at such temperatures the barrier material tends to melt, thereby reducing the integrity baw < the applicability of the container is destroyed.

Accordingly, the main purpose of the invention is to produce a multilayer plastic material, in particular a hollow plastic container.

4 f JH β 2 UI U / 3 9-

ORIGINAL INSPECTED

- 3- \. . 235R153

A particular purpose of the invention is to provide a plate-shaped plastic material and a / container, as described above, to produce the opposite increased Temperatures are resistant and have a barrier resistance. ' stand.

An additional purpose of the invention is to to create a container as described above, which has its barrier resistance compared to a flowable one. Medium retains when repeatedly elevated temperatures is exposed. ,

Another purpose of the invention is ^ n, a Container, as described above, to produce, which can be prepared or produced in a simple and expedient manner according to the invention. ,.

According to the invention, a multilayer plastic hollow body is created, which is resistant to elevated temperatures and has a barrier resistance, which has an outer first part of a material which is resistant to temperatures of up to about 80 ° C, preferably 104 ° C (± 75 or 220 ° F), and further comprises an inner second portion of a material that is resistant to temperatures above about 80 ° C, preferably 104 ° C (175 or 220 ° F), with the container having a third portion or respectively has a third barrier layer made of a thermoplastic material between the first and second sections. Preferably, an inner fourth part of a material is provided which can withstand temperatures of above approximately 80 ° C., the fourth part being arranged between the first and the third part. \

The container or hollow body according to the present invention offers a variety of highly desirable benefits. Accordingly, the new container faces elevated temperatures Resilience and also has a bar barrier resistance, in particular a barrier resistance to flowable media, for example a gas

A0982A7G739 '

ORIGINAL INSPECTED

2 3 F ^ 1 5

barrier resistance, the barrier resistance being upright is retained even if the hollow body is repeatedly exposed to elevated temperatures.

According to the invention, a multilayer sheet-like plastic material is also created, which has the same highly desirable properties as the hollow body, the sheet material a first component of a material which is resistant to temperatures above approximately 80 ° C is a second component of a material that is resistant to temperatures above approximately 80 C, and a third barrier layer of thermoplastic between the first and second components, which extends in substantially the same manner as the first and second components, all of which Components are attached or adhered to one another substantially over their entire contact surface, and although in accordance with the hollow body according to the invention.

The principle of the present invention is based on the inclusion of the barrier layer between the two layers made of heat-resistant plastic, so that the barrier layer gradually softens or even melts and after exposure or application to an elevated temperature and subsequent cooling to ambient temperatures resumes its shape on the spot.

For example, a heat resistant container could easily be molded from a material such as polycarbonate, polypropylene, phenolic resin, or polysulfone. In a corresponding manner, a plastic barrier shell according to patent application P 21 hk 478.0-16 can be produced by using, for example, polyvinylidene chloride, polyvinyl acetate, Barex (an acrylonitrile-styrene copolymer) or Lopak (a methacrylonitrile polymer), but the barrier materials are used a softening or melting point which is below those temperatures which the container

U Ü 9 Ü2 UI 0 7 3 9

ORfGINAL INSPECTED

_5-235 9153

should withstand or which the containers should withstand. This obviously leads to a completely unsatisfactory situation.

According to the invention is a. Shell made of a layer structure or a sandwich made so that in the container produced the barrier layer is between two layers is enclosed from a heat-resistant plastic. In use when the container according to the invention is exposed to elevated temperatures, that is the low melting point Layer trapped between the refractory layers and can and likely will be frequent to be softened, if not melted, which goes without saying depends on the application of the temperature. Because the low-melting layer is included and essentially is arranged in conformity with the surrounding protective layers, it lacks mobility and must Remain in place. Accordingly, the lower melting layer becomes normal upon cooling with no change Returned state. For example, the lower melting layer cannot shrink and can thereby does not form cavities, it cannot tear away, agglomerate or otherwise deform with exception in the way that it is enforced by the outer protective layers. As the lower melting ingredient one Thermoplastic material is, according to its properties, with repeated softening, melting or cooling down.

The invention is illustrated below with reference to the drawing, for example explained. ;

Fig. 1 shows a longitudinal section of a more or multilayered shell that can surround a blown core.

Fig. 1A is an enlarged cross-sectional view along the line 1-la according to FIG . multi-layered

', Ul) UUlU / 07 3 9

-6- 23-9153

Sheath shows or according to the alternative solution according to the present invention showing components of a plastic sheet according to the invention.
Fig. 2 is a longitudinal sectional view of a spray

form showing a blow core covered by a shell.

Fig. 3 is a corresponding view showing the blow- shows the core withdrawn from the injection mold, with the preform resting on the blow core is located.

Fig. 4 is a corresponding view showing the blowing core in the blow position within the blow mold and within the hollow object according to FIG Invention shows in the blow mold cavity. Fig. 5 shows the multilayer plastic hollow body

according to the invention.
6 is a perspective view showing a

Figure 9 shows another alternative embodiment of the preformed envelopes.

Figure 7 is an enlarged cross-sectional view taken along line 7-7a of Figure 6 showing a multi-layer web of two layers. In Fig. 1, a multi-layer shell 1 for a blow core is shown, which is used in the subsequent deformation process when forming the hollow body according to the invention, the shell having an inner surface which is formed very closely approximated to the outer surface of the blow core. The thickness of the shell can vary, depending, for example, on the materials used and the final, desired hollow body. Accordingly, sidewalls 2 can be thin, for example about 0.025 to about 0.05 mm (0.001 "to 0.020"), while their bottom section j can be two to ten times the thickness of the wall and can be of a shape suitable for ura with

ACJ ¹ Jb iu ' U, / j 9

Align the mold. The edge, k of the shell 1 can be in accordance with the upper region of the hollow body to be produced. As mentioned above, such casings can consist of many layers, as shown in FIG. 1A, of which the middle layer - the barrier layer, can consist, for example, of polyvinylidene chloride, polyvinyl acetate, acrylonitrile polymers or of methacrylonitrile polymers. The outer layers shown in FIG. 1A, layers b and c, can consist of any heat-resistant plastic, preferably a thermoplastic, for example polycarbonate, polypropylene or copolymers of these thermoplastics. Of course, the outer layers can consist of the same plastic or, as desired, of different plastics. Such casings can be made from a variety of plastics at reasonable cost by known processes, for example by hot forming, deep drawing, powder coating processes, casting processes, these processes being described in the Modern Plastics Encyclopedia, published by McGraw-Hill, Inc. 1969 and 1970, respectively pages 53 **, 59 ^ and 602 have been described. Other known methods of making thin-walled plastic molded articles can also be used.

The casings shown in Fig. I are in a spray- Molding device according to FIG. 2 used, which consists of a blow core 5, an injection mold 6 and a tool for molding the open end of a hollow body, the neck ring 7, ordered. A passage 8 connects the injection mold 6 with a feed device for hot plastic, which is in a cylinder 9 is kept from which the melted plastic into the injection mold 6 by means of a piston 10 sufficient pressure can be pressed in to achieve rapid Filling the space between the blow core 5 and the Injection mold 6 and the space between the blow core

A 0.9-8>: 47 U 73 9

ORIGINAL INSPECTED

and the neck ring 7 »which is connected to the injection mold 6 stands to bring about.

The preform ii formed in the device shown in FIG. 2 can be removed from the injection mold 6 together with the blow core 5 and the neck ring 7, as shown in FIG. 3, and introduced into a blow mold 12. The pressure medium obtained from a source (not shown) can be introduced into the interior of the preform 11 through pressure medium passages 13. The blow mold 12 has a mold cavity Ik which corresponds to the shape of the hollow body to be produced, and the blow mold 12 can be made of two halves which can be separated in order to facilitate the removal of the hollow body completed in the blow mold 12.

The above-mentioned movements of the blow core can be carried out, for example, by a device those in U.S. Patents 2,298,716, 3,100,913, 3,183,551 and 3,029,468. In each of these devices One or more blow cores can be used at the same time, and they can be used from one job another individually or in groups of several blow cores.

When working according to this method, casings according to FIG. 1 can be produced by any method, independent of the injection blow molding process described here. Optionally, the casings can be manufactured on site, for example by repackaging the plastic layers and wrapping the layered plastic film tape tightly around the blow core 5. The material of the casing must have deforming properties which correspond to or exceed those of the material of the preform, and at the temperature normally maintained for expanding or inflating the preform into the cavity 1h of the blow mold 12. The same plastic material is therefore preferred for the outer first section

409824/0739

ORIGINALINSPECTED

as selected for the inner second part.

If a three-layer cover is used, can it may be desirable to pre-treat the casing for adhesion the shell on the preform when normally used for Injection molds to ensure the temperature used. For example can be the outer surface of the shell 1, which is in contact with the injected plastic of the preform 11 come, are pretreated by known processes, which bring about adhesion of plastic surfaces or support financially. For example, if the envelope is made of polypropylene, its outer surface can be exposed to a flame be treated. In any case, the shell must be made with the material of the preform and the function do not affect the hollow body to be produced.

The sheath 1, which fits flush over the blow core 5, is done by hand or by mechanical means, which.not are shown before the blow core is introduced into the injection mold 6 is pushed over this. With the blow core in place within the injection mold, can the tip of the blow core, which is surrounded by the bottom part 3 of the shell, is held firmly against the inner wall of the injection mold be, and if it is desired, the blow- to stabilize the core.

After the blow core is in its place, hot plastic is injected into the injection mold through the opening 8 under the action of the piston 10, which is shown in FIG a pressure cylinder 9 works. After the injection, the hot plastic surrounds the shell 1 under pressure. As a result the intimate contact between the hot plastic and the exposed area of the shell exists, the The envelope is heated rapidly until its temperature approaches that of the injected plastic. At this The adhesion or gluing of the two materials occurs at temperature easily, and the material of the cover becomes beyond that further heated sufficiently to keep the casing -

4 098 IkI 0 739

ORIGINAL INSt ³ ECTED

-ίο-- 23 ^ 153

at the same speed as that of the injected To make plastic deformable. United accordingly the shell with the injected plastic and connects with this in order to form the composite or multilayer preform 11.

After the preform has been formed by injection, the blow core 5 is removed from the injection mold together with the neck ring 7 and with the preform 11 located on it, as shown in FIG. 3. Next, it is inserted into the k in Fig. Tuyere shown 12th

For a more precise arrangement of the blow core 5 in the blow mold 12, the blow core can be pressed against the bottom part of the blow mold are pressed, the bottom part 3 of the shell being located between the blow core and the bottom part of the blow mold. Accordingly, the blow core is aligned in the blow mold in the same manner as in the injection mold held. The next stage is pressure medium, usually compressed air, into the preform by means of pressure medium Passages 13 are introduced and the preform is placed in the blow mold 12 expanded into it to the shape of the cavity 14 of the Assume blow mold 'as indicated by broken lines in Fig.. Working medium pressure is maintained until the blown object cools sufficiently in contact with the wall or the walls of the blow mold 12 so that it can be removed from the blow mold.

The multilayer plastic hollow body according to the invention is shown in Fig. 5 as removed from the blow mold.

Although the aforementioned preferred method has been found to be capable of achieving one in the highest To obtain dimensions of advantageous hollow body in a simple and expedient manner, the person skilled in the art also offer other methods to obtain the container or hollow body according to the invention.

¥ ie has already been stated above, the hollow body according to the invention retains surprisingly

409824/0739

ORIGINAL INSPECTED

Way its resistance to elevated temperatures and also its barrier resistance to flowable media, for example its gas barrier resistance, its resistance to the passage of Oxygen and carbon dioxide or its solvent resistance.

A modified embodiment of envelopes is shown in FIG. 6, in which dome-shaped envelopes 20 are carried on a web 21 which are carried by non-deformed portions of the web 22. Of course, the casings 20 are separated prior to use in the method according to the invention. If desired, the casings can be stacked in this form in an expedient manner and each conveyed one after the other to the blow core. As shown in FIG. 7, the shell can have only two layers, layer a ^{1 representing} the barrier layer and layer b ^{1 representing} the heat-resistant layer.

The present invention also relates to a multilayer plastic sheet material, as shown in Fig. 1A, which has properties which correspond to those of the aforementioned hollow body. The plate material can be prepared or produced by any desired method, for example by joining by means of an adhesive material, by joining the Edge parts, for example through edge welding or connection with an adhesive or through joint extrusion, Of course, the plate-shaped material can be prepared or manufactured in shorter lengths or in longer lengths will. If long lengths are provided, the plate-shaped material according to the invention can expediently be supplied in the form of rolls.

It can be used for both, for the plate and the hollow body be advantageous according to the present invention, the bar- barrier layer to be easily removed or removed from an exposed edge. ~.

409824/0739

ORIGINAL INSPECTED

- ¹² - 2 3 5 Ό 5 3

The Plattennimaterial according to the invention naturally has a wide variety of uses, usually whenever resistance at increased Temperature and a barrier resistance are required. For example, cooking containers or Cooking bags obviously have a resistance to elevated temperature and require one in storage Barrier or blocking resistance. This is also the case, for example, with products that are filled in hot or pasteurized in the container.

The components of the plate material are as stated above. Accordingly, it is evident that a variety of materials are used for both the container and the plate material according to the invention can be. The barrier material can be a barrier material to a flowable medium with high temperature properties that are inferior to the temperature resistance of the temperature-resistant component or the temperature resistant layer, i.e. which are at least about 28 degrees (50 F) lower. Accordingly, should the temperature-resistant layer its structural. Maintain integrity at the desired temperature, while the barrier layer becomes liquid or flowable at this temperature. Accordingly, any one can Variety of temperature-resistant layers selected The choice depends on the inner layer and the properties desired. For example, can Acetate polymers, polycarbonates, phenolic resins, polysulfones, Polyolefins, polyimides, ionomer resins and the like can be used. The outer layers can be of the temperature resistant Layer may be different or, if desired, consist of the same material.

h 0 y 8 2 U l U 7 3 9

ORIGINAL INSPECTED

Claims (14)

235S153, Claims f V I i.! Multi-layered hollow body that is resistant to increased temperatures and has a barrier resistance with an outer first part of a material which can withstand temperatures above approximately 80 ° C (i75 ° F) is resistant to, and with an inner second part of a material which has temperatures up to is resistant to above about 80 ° C (175 ° F), thereby characterized in that the hollow body has a third barrier layer (a) of a thermoplastic material between the first and the second part (b, c). , 2. Hollow body according to claim 1, characterized in that that the first and second parts (b, c) are made of thermoplastic material and are resistant to temperatures up to about 104 ° C (220 ° F) and that the third part (a) is a barrier layer against one is flowable medium. 3. Hollow body according to claim 2, characterized in that that the first part is made by injection molding. 4. Container according to claim 2, characterized in that that the second part is made by drawing or deep drawing. 5. Container according to claim 2, characterized in that that the material of the first and the second part independently of one another from the group of polyolefins, polycarbonates, Polysulfones; Phenolic resins, polyimides, ionomeric resins and the acetate polymers. 6. Container according to claim 2, characterized in that that the "third. ~ Te.-il, the barrier layer, is made of one material from the group of polyvinylidene chlorides, polyvinyl acetates, Acrylonitrile polymers and the methacrylonitrile polymers are selected is. .- ■ ' 7. Container according to claim 2, characterized by a fourth part made of thermoplastic material, which 409824 / Ü739 INSPECTED Temperatures up to above about 80 ° C (175 ° F) is resistant and is arranged between the first and the third part. 8. A container according to claim 1, characterized in that the first part is substantially in conformity with the first and second part is formed. 9. A method of manufacturing a hollow body or container with a barrier resistor and a resistor against elevated temperatures, characterized by the layering of a barrier layer made of a thermoplastic material material between two layers of a material which Withstand temperatures in excess of about 80 ° C (175 ° F), and by forming the layered material in a multi-layered plastic hollow body. 10. The method according to claim 9, characterized by use a material for the barrier layer, which is a barrier or barrier to a flowable medium forms. 11. Multi-layer sheet material with a Resistance to elevated temperatures and a barrier resistance with a first part of a material which Temperatures up to above about 80 C (175 ° F) is resistant, and with a second part of a material which can withstand temperatures above about 80 C (175 ° F), characterized by a third part (a) between the first and second parts (b, c), which is located essentially in the same extent to the first and the second part, and a barrier layer from a thermoplastic plastic material, the parts essentially over their entire contact or areas of contact stick to one another. 12. Plate material according to claim 11, characterized in that the barrier layer is a barrier or barrier— layer is opposite to a flowable medium. 13. Plate material according to claim 12, characterized 40 9.824 / 0739 235 0 draws that the materials of the first and the second Partly independently of one another from the group of polyolefins, polycarbonates, polysulfones, phenolic resins, polyimides, ionomer resins and acetate polymers are selected. 14. Plate material according to claim 12, characterized in that that the material of the barrier layer from the group of polyvinylidene chlorides, polyvinyl acetates, acrylic nitrile polymers and methacrylonitrile polymers. £ 0982 ^ / 0739 ORIGINAL INSPECTED Blank page