JPH0639906A - Multi-layer molded container and its manufacture - Google Patents

Abstract

PURPOSE:To reduce contact of contents with atmosphere by making a multi- layer molded container of a composite parison consisting of a closed parison for an outer layer and the other closed parison for an inner layer which fits into the form layer, and by displacing the inner layer at the top within the outer layer to open and close a vent between the layers. CONSTITUTION:A closed parison 1 which is made of thermoplastic resin such as polyester, polyvinyl chloride, polypropylene etc., with male threads 17 and a collar 18 at the top opening for making an outer layer, and another closed parison 2 which is made of a layer of a polymer of the thermoplastic resin with or without polyester or a layer consisting of a thermoplastic resin without polyester, having a flange 3a at an outer brim of the top opening for making an inner layer are provided. A composite parison consisting of the parison 2 fit into the parison 1 is blow-formed by biaxial orientation to make a multi- layer molded container, and a vent between the layers may be closed or opened by post-molding rotation or moving up and down of the top portion of the inner layer 2 within the outer layer 1.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an interlayer easily peelable multilayer molding container made of a thermoplastic resin having polyester, polyvinyl chloride, polypropylene, polyacrylonitrile, polystyrene or the like as an outer layer, and more specifically,
While maintaining the outer shape of the container and selectively responding to pressure resistance, rigidity, transparency, gas barrier property, shrinkability, etc., preventing contact with the outside air due to intake from the mouth and filling the necessary container It is possible to pour out substances, for example, carbonated gas-containing drinking water, ordinary drinking water, liquor, seasonings, chemicals such as eye drops,
The present invention relates to a multilayer molded container by a biaxial stretching blow method suitable for filling a developing solution and the like and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, containers for filling carbonated gas-containing drinking water, ordinary drinking water, liquors such as beer, chemicals such as eye drops, and cosmetics have been made by a biaxial stretching blow mainly composed of polyethylene terephthalate. Layered containers are widely used. In addition, there are some containers which are made by blending or sandwiching polyethylene terephthalate with another resin having a gas barrier property to improve the gas barrier property by biaxial stretching blow.
A container made of polyethylene terephthalate can be molded by a biaxial stretching method, for example, US Pat. No. 3,733,309.
As shown in the specification of the publication, the container wall excluding the head is molecularly oriented and has not only excellent pressure resistance, rigidity and transparency but also various performances such as low gas permeability of oxygen and carbon dioxide gas. It is possible to obtain a container. Polyvinyl chloride is also used for cosmetics, detergents, chemicals, drinking water, alcohols, etc. due to its rigidity, transparency and gas barrier property. Further, polypropylene is effective in a field where a function of high heat resistance is required, and polyacrylonitrile is used as an industrial chemical container due to its rigidity and gas barrier property. Further, polystyrene is used as a beverage or food container.

However, the container described in the preceding paragraph exhibits a desired desired performance in a state where the filling substance in the container is hermetically sealed. However, in any case, once the container is opened and unsealed, the filling substance is used. It is difficult to avoid contact between the filling substance and the outside air unless the filling substance in the container is used up at once with the intake of the used amount. Oxidation by inflowing outside air and bacteria and other foreign substances mixed with it, diffusion of useful components,
It was not possible to deal with moisture absorption, deterioration, and changes in concentration due to dew condensation on the inner surface of the wall.

[0004]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In a large-sized container for a beverage, particularly a carbonated gas-containing beverage, the amount of each person who drinks at one time is limited even if there is an individual difference. In the meantime, by the action of correcting the imbalance between the inflowing air pressure and the beverage injecting gas in the container and the interaction with the mouth leakage,
This is a so-called unconscious state. The same applies to small and medium-sized containers, although there are some differences. In products such as soft drinks and beer where carbon dioxide or the presence of carbon dioxide and alcohol are important, the gas pressure and the reduction of volatile components are fatal, and they are discarded when they become stagnant. There are things. Further, the air contact, which initially existed only in a narrow area of the head, expands rapidly on the wall surface and the liquid surface due to the inflowing outside air, causing oxidation and deterioration, which causes a change in taste.

Further, in a container filled with foods such as edible oil and soy sauce, and a seasoning, an outside air inflow and an agitating action occur each time the content is used, so that not only the liquid level but the entire inner wall surface adhering layer of the container is caused. As a result, the quality is deteriorated due to oxidation and deterioration. Further, not only liquid substances but also viscous substances, such as sauces, are inhaled from the mouth due to the elasticity of the container each time they are used, and suffer deterioration due to oxidative deterioration in the same manner as described above.

Further, in the case of a container filled with a drug such as eye drops, dew condensation occurs on the inner wall surface due to the temperature difference between the inside and the outside of the container. Therefore, as the content volume decreases, the concentration of the drug solution increases and reused. Since it is sometimes used while absorbing dew condensation, the concentration of the chemical liquid is unevenly distributed. In addition, if the tip of the container touches the eyelids or eyelashes, etc., the drug solution may become contaminated or turbid due to eyes and other bacteria, and it is always stated in the precautionary statement for use. one of.

Further, it is known that when the content substance is filled in a heated state, for example, sauces and the like, when the container wall is heated to 70 ° C. or higher, wall contraction or deformation due to it occurs. This is likely to occur in parts other than the unstretched part of the head and the stretched part of the body, and there is a difficulty in filling the contents after heat sterilization or in the heated state without cooling. Further, there is a container in which the stretch ratio of the portion that easily undergoes heat shrinkage is increased, but even if the heat shrinkability is improved, it is unavoidable that the inflow of outside air when using the filler is unprotected.

Further, the polyethylene terephthalate biaxially stretch blow molded container has a weak point that the internal volume decreases with time immediately after molding. This means that the tightly sealed filling is pressurized, which causes deterioration of the appearance and contents of the product. In addition, the higher the ambient temperature, the greater the shrinkability and the risk of the contents blowing out when the cap is opened. Furthermore, due to the carbon dioxide permeability and absorbency of the container wall, small containers are extremely uncommercial for carbon dioxide-containing beverages. To improve this, whether a gas barrier resin is coated or sandwiched between layers. However, it is vulnerable to the inflow of outside air into the container.

Further, even in the containers made of polyvinyl chloride, polypropylene, polyacrylonitrile, and polystyrene, the protective performance against the filling material is excellent, but the container is not susceptible to oxidation, moisture absorption, and deterioration due to inflow of outside air into the container. On the other hand, it is also defenseless.

As described above, the physical properties of the above-described container inevitably cause an inflow phenomenon into the outside air as the filling material decreases due to the use of the filling material, and the protective strength against the filling material and the external barrier property are gas permeability and gas permeability. Except for absorbability and contractility, it is almost satisfied before opening and opening, but the internal barrier property after opening and opening will deteriorate, or rather protection against internal inflowing outside air and its contaminated substances and miscellaneous bacteria. It is obvious that the property is equal to zero, and it must be said that it is vulnerable to oxidation, gas diffusion, moisture absorption, deterioration, etc. The present invention aims to solve the above-mentioned problems, and the content protection strength from the time of filling of the content substance and the barrier property against various gases and liquids are the same as or better than conventional ones, and this excellent Even if the barrier property is reduced by the use of the filling material, it is possible to provide a multilayer molded container capable of continuously performing desired performance until the end of use of the filling material by keeping the intake air from the mouth to a minimum. To do.

[0011]

A container according to the present invention comprises a multi-layer wall formed by biaxial stretch blow molding of a composite bottomed parison of a thermoplastic resin, and the inner and outer layers are easily peeled off. External ventilation is performed from the interlayer ventilation holes that appear due to the rotation or vertical movement of the inner layer of the head between the separated layers, and the appearance of the container is always retained and restored depending on the elasticity of the outer layer. In the outer layer container, the inner layer container is generated and shrinks along the center line of the container according to the usage amount of the contents, thereby consistently protecting the external environment from the beginning to the end of use of the container filling material. And

The multi-layer container of the present invention comprises polyester, polyvinyl chloride, polypropylene, polyacrylonitrile,
A bottomed parison made of polystyrene etc. and a single layer of polyester or other thermoplastic resin, or gas barrier resin such as polyester and polyamide, polyolefin such as polypropylene and gas barrier such as ethylene / vinyl alcohol copolymer resin. Polyethylene isophthalate is polymerized with resin, polyethylene terephthalate, and a glycol component such as polypropylene glycol is added to lower the resin molding temperature to form a multi-layered inner layer by combining with ethylene / vinyl alcohol copolymer resin. A bottomed parison is separately molded, and the parison is fitted to obtain a composite parison. When the resin molding temperatures are the same, a composite parison obtained by integral molding is obtained.

Next, the composite parison is heated to a stretching temperature,
A stretched plastic container is obtained by biaxial stretch blow molding in a split mold. After molding, the bottomed parison as the outer layer becomes a container wall having conventional pressure resistance, rigidity, transparency, gas barrier property, and the like. The bottomed parison that is the inner layer has a layer thickness design that can be stretched into a film after molding,
It is not necessary to have pressure resistance, rigidity and transparency in the outer layer, but rather the resin design should focus on flexibility and gas barrier properties. The inner layer after stretching directly protects the filling material, and due to the interlayer ventilation function of the head portion and the interlayer easy peeling initiation function, the inner layer shrinks in the outer layer container following the volume reduction due to the use of the filling material.

The interlayer ventilation holes of the multi-layer container of the present invention are obtained by the dynamic shape or static shape of the container head, depending on the required function such as the viscosity of the filling material. That is, there is an air-bleeding continuous groove having a low inclination toward the bottom from the mouth to the bottom on the outer surface of the inner layer of the parison before stretching and / or the inner surface of the outer layer. After the working stretch forming, the body part disappears by stretching, and the head part becomes a vent groove communicating with the vent hole of the mouth part or the head wall part. The inner layer of the inner and outer parison of the unstretched portion, the inner layer is rotatable or vertically movable in the outer layer, the upper end concave portion of the mouth outer layer, the outer portion of the mouth inner layer or the convex portion below the inner layer flange is fitted, It is possible to prevent the excessive rotation of the inner layer and to obtain an openable / closable interlayer ventilation hole that communicates with the interlayer gap below the uneven portion as the head inner layer rotates. Further, the peripheral ventilation hole is obtained by moving up and down by the rotary force of the lid being passively passed by the flange of the inner layer and the circumferential step provided on the outer surface of the inner layer and the circumferential step provided on the inner surface of the outer layer being screwed or beaten. You can also Further, it can be communicated with the ventilation hole of the head wall portion by the rotation.

In the case of a highly fluid filling material, if the container is erected upright after pouring, it will fall rapidly and will be adhered to the upper end of the inner layer or the upper end of the inner layer flange or the upper end of the inner layer flange in order to prevent the accompanying outside air suction action. Intake into the inner layer container is prevented by providing a valve body or a pouring amount adjusting lid part that is adhered or fitted to the fixed ring to prevent inhalation into the container, and the contact of outside air with the filling substance is minimized. It will be possible to be blocked.

Since the inner layer shrinks due to the use of the filling substance, the inner layer becomes suspended along the center line of the container in the outer layer container each time the easy peeling is repeated. It is supported by the ridges or flanges and does not fall off. In addition, the bottom is not necessarily required depending on the shape of the container, but from the viewpoint of securing the flow path when pouring the filling substance and aesthetics, it is connected to the interlayer bottom via an adhesive layer when the bottomed parison is fitted. The layers can be joined together or when the parison is formed.

Providing a protrusion on the inner layer outer protrusion of the container mouth or on the outer periphery of the inner layer flange or on the outer periphery of the flange joining ring,
By contacting the protrusion provided on the inner circumference of the lid, it becomes possible to automatically open and / or close the interlayer ventilation hole when opening and closing the lid when using the filler.

A ring provided with a mouth flange on a bottomed parison as an inner layer and an interlayer vent hole or a vent valve body when fitted with a bottomed parison having a flat upper end on the outer layer as a ring or a hollow having the function. It is also possible to attach or apply a ring or a sealing ring body and, after biaxial stretching, to impart interlayer sealability when closing and interlayer breathability when opening.

As described above, the multilayer molded container of the present invention includes a container having an outer layer made of other similar thermoplastic resin, such as polyester having ethylene terephthalate as a main unit, which exhibits properties by being biaxially stretched. Since they are formed, they have different properties, but in addition to having excellent pressure resistance, rigidity, and transparency, a container with a high external barrier property that has low gas permeability such as oxygen and carbon dioxide gas is also obtained. , In the outer layer container, a film-shaped inner layer container having a barrier property is formed by easy peeling between layers, and oxidation and diffusion of the container filling material by preventing external air from flowing into the inner layer container by providing interlayer breathability, Moisture absorption, deterioration,
Provided is a stretched plastic container having extremely few adverse effects such as changes in concentration due to dew condensation on the inner surface of a wall.

The easily peelable multi-layer molded container according to the present invention is manufactured by paying attention to the temperature range in which it can be stretched while utilizing the inability to melt the resin below the melting point. That is, polyester having ethylene terephthalate as a main unit, polyvinyl chloride, polypropylene, polyacrylonitrile,
An upper end that is an inner layer that consists of a bottomed parison made of a resin such as polystyrene that is an outer layer with an opening, and a polyester or a polyester or other thermoplastic resin polymerization layer or a multilayer or a thermoplastic resin constituent layer that does not contain polyester After forming the bottomed parison of the opening on one and / or both sides with inter-layer evacuable space, these are fitted to form a composite bottomed parison, or the top end formed by Ikkyu where the inner and outer layers are in close contact A composite parison with an open bottom. The composite parison is heated to an appropriate temperature at which it can be stretched, placed in a split mold, and the parts other than the head are biaxially stretched by a blow molding method to form a container wall.

In the unstretched head portion of the container, the inner layer can rotate or move up and down in the outer layer, and the inner layer is fixed as long as external force is not applied because it is connected to the stretched portion. Further, the interlayer ventilation holes can be opened when the parison is fitted and when the biaxial stretch molding is performed.

What is important in the method for producing a multilayer molded container of the present invention is the strength stability and interlayer residual air of the outer container wall formed due to the composite parison. In the normal constant heating of the body, the expansion rate of the inner layer is constant and the air bleeding between the composite parisons becomes partial, and residual stress and residual strain left in the outer layer due to residual air, and polyethylene terephthalate or other resin. Even if it is present, it will lead to non-uniformity of the degree of orientation of molecular chains. Therefore, as an interlayer degassing method, by giving a high gradient temperature at the bottom of the parison, especially at the bottom of the parison, which is the inner layer, and a low gradient temperature toward the lower end of the head, the difference in molecular motion in the material is obtained, and The pressure causes the container wall to expand in the order of higher molecular motion, and the interlayer air is exhausted from the interlayer ventilation hole, resulting in the strength stability of the outer layer.

Further, when the container filling material is used, the interlayer vent holes are opened and closed by the rotation or vertical movement of the inner layer of the head, so that the delamination which is started at the same time can be clearly progressed. Since the inner layer of the portion relatively thicker than the outer layer is less flexible than the body wall, the air bleeding groove is adhered to the inner surface of the outer layer according to the stretching ratio to leave substantial unevenness and the inner layer of the head rotates or It is possible to increase the strength of easy peeling due to vertical movement. Furthermore, as the inner layer peels off, the inner layer contracts along the center line of the container and becomes suspended from the head, and the inner and outer layers are connected at the bottom of the container in order to secure a flow path for the fluid filling material and to ensure stability. By doing so, the filling substance can be stably poured out.

Furthermore, when a relatively ductile material such as polyethylene is used for the parison which is the inner layer, and when a gripping tool is inserted from the mouth to increase the buckling property and the strength of the container shoulder, biaxial stretching is performed. Prevents the inner layer from falling off and the accuracy of the mouth to be inconsistent,
Moreover, it becomes possible to further enhance the molecular orientation from the lower end of the head to the shoulder.

As described above, the multilayer molded container of the present invention comprises a polyester having ethylene terephthalate as a main unit, polyvinyl chloride, polypropylene, polyacrylonitrile, polystyrene and the like, and a bottomed parison as an outer layer and a polyester. Or, a bottomed parison with an opening at the upper end, which is an inner layer made of a polymerized layer of polyester and another thermoplastic resin or a multilayer or a constituent layer of a thermoplastic resin that does not contain polyester, and / or both of which can be degassed between layers. In the step of forming and forming a composite bottomed parison after molding, and in the step of heating the composite parison to an appropriate temperature, from the bottom of the inner and outer layer parisons, especially the inner layer parison before or after the parison is fitted. The stretching heating temperature reaching the head is increased in the bottom and the lower part and is gradually decreased in the upper part, and the composite heating is performed. Place the Lison in the split mold, and use the blow molding method to perform biaxial stretching while degassing the layers other than the head part, and leave a substantial unevenness while adhering the degassing groove to the lower surface of the head part with the inner surface of the outer layer. In the outer layer of unstretched head portion, the layer of the unstretched head portion is rotated or moved up and down by an external force to clearly separate the layers, and the interlayer ventilation holes are opened and closed easily. A method for producing a multilayer molded container is provided.

[0026]

The multi-layered molded container according to the present invention has an inner layer having both barrier property and flexibility, and an outer layer having gas barrier property, pressure resistance, rigidity, transparency, etc., which is separated by easy peeling. In the part, the ventilation part communicating with the upper and lower layers between the inner and outer layers and the interlayer ventilation from the arbitrarily openable and closable interlayer ventilation hole generated by the rotation or vertical movement of the inner layer opening part, the outside air equivalent to the use of the filling material of the container Will be aerated between the layers without contacting the filling material. It is possible to easily install a valve element on the inner layer of the mouth or the flange of the inner layer in order to more sufficiently prevent the intake action other than the head space required during the use of the container filling material. You can choose. As the container filling material decreases, the inner layer gradually loses its complementarity due to the adhesiveness with the outer layer and becomes a suspended state from the head, so it is supported by the mouth outer protrusion or the mouth inner layer flange at the container head. At the bottom of the container, it is also possible to stop the inner bottom at the narrowed portion of the outer layer of the container by joining by bonding an adhesive resin or the inner and outer layers or by the shape of the container. By either method, the inner layer shrinks vertically as a flexible container inside the container along the centerline of the container, and the container filling material is at the bottom of the container during storage, so it always stabilizes the container and fills it. A flow path is secured when using the substance.

As described above, the shape of the container has a function of maintaining and restoring the filling material from the beginning to the end of use, and
By minimizing the external air contact with the filling material in the container by interlayer ventilation, the filling material in the container has a function of preventing oxidation, moisture absorption, deterioration, diffusion of active ingredient, condensation on the inner wall, etc. from the start to the end of use. The quality is remarkably improved, and the quality can be maintained for a longer period than ever before.

[0028]

Embodiments of the multilayer molded container according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a central longitudinal side view showing an embodiment of the multilayer molded container of the present invention, and FIG. 2 is a central longitudinal cross section showing an embodiment of a bottomed parison with an upper end opening serving as an outer layer of the multilayer molded container of the present invention. FIG. 3 is a side view, and FIG. 3 is a central longitudinal side view showing an embodiment of a bottomed parison having an upper end opening which is an inner layer of the multilayer molded container of the present invention. FIG. 5 is a central longitudinal side view showing an embodiment when placed in a mold, FIG. 5 is a central longitudinal side view showing an embodiment when biaxially stretching the multilayer molded container of the present invention, FIG.
FIG. 7 is a front view showing an embodiment of the multilayer molded container according to the present invention when a head vent hole is opened, and FIG. 7 is a cross-sectional view of a head I-I in FIG. In FIG. 1, reference numeral 11 is a multilayer molding container in which a composite parison having an upper end opening is biaxially stretched except for the head portion by a biaxial stretching blow molding method, and reference numeral 5 is a spout. The outer layer indicated by reference numeral 1 is made of polyethylene terephthalate having high pressure resistance, rigidity, transparency, moisture resistance, water resistance and gas barrier property, and the inner layer indicated by reference numeral 2 is also made of polyethylene terephthalate. In the inner layer, from the viewpoint of gas barrier properties, polyethylene terephthalate is sandwiched with an aliphatic polyamide having an aromatic ring, and polyolefin such as polypropylene is sandwiched and laminated with an ethylene / vinyl alcohol copolymer resin to form a multilayer structure. It can also be a functional film. In the outer layer, it is possible to use a thermoplastic resin such as polyvinyl chloride, polypropylene, polyacrylonitrile, etc., which can be improved in strength, gas barrier property, and transparency by biaxially stretching. The resin can be selected according to the function, and in the inner layer, the resin is selected only according to the function of protecting the content and maintaining flexibility. An adhesive layer is not interposed between the inner and outer layers of reference numerals 1 and 2, and has an easy peeling property that peels with a small external force.

In FIGS. 2, 3 and 4, the bottomed parison of the upper end opening, which is the inner layer of reference numeral 2, is
It is fitted in the bottomed parison of the upper end opening which is the outer layer of reference numeral 1. At the time of fitting, the spaces for degassing shown by reference numerals 7 and 7a are provided, so that the fitting can be easily performed. By molding the inner and outer layers separately when there is a difference in molding temperature between the resins to be the inner layer and the outer layer, and noting that there is a coincident point in the region of biaxial stretching temperature, By paying attention to the property that the same resin does not adhere even if it sticks below its melting temperature, it is possible to form a composite parison and obtain a multi-layer molded container with easy peeling by biaxial stretch blow molding. is there. Further, when there is a coincidence point in molding temperature even between different kinds of resins, it is possible to obtain a multi-layer molded container having a layer easily peelable by a single parison. By utilizing such easy peeling property between layers, the suctioned outside air into the container can be separately housed in the container, and the contact of the substance filled in the container with the outside air can be minimized.

The interlayer ventilation holes of the easily peelable multilayer container of the present invention are obtained by rotating or vertically moving the inner layer of the head. Reference numeral 3a in FIG. 6 is a mouth flange of the inner layer, and reference numeral 3b is an outer protrusion of the mouth portion of the inner layer, which fits closely with the recessed portion 3c of the outer layer. The tip of the reference numeral 3b is shallowly fitted with the reference numeral 3d to prevent over-rotation of the inner layer. When the ventilation hole is closed, the reference numerals 3d and 3e are in close contact with each other. The concavo-convex portion is separated by twisting the inner layer or the inner layer flange or the inner layer joined body, and the ventilation hole of reference numeral 8 is generated and sealed by turning or vertical movement due to twisting. Also, although not shown, a ring or a sealing ring body having a vent hole or a vent valve body is attached or applied between the upper end of the outer layer and the lower end of the inner layer flange, and the inner or outer layer is rotated by rotating or vertically moving the inner layer of the head. It is also possible to provide the interlayer breathability and the sealing property by the elasticity of the intermittent screw-shaped or circumferential protrusions, the elasticity of the ring itself, or the like.

The interlayer ventilation hole of the present invention can be obtained by rotating or vertically moving the inner layer of the head, and the opened ventilation hole of reference numeral 8 penetrates from the outer end of the mouth to the lower end of the head and is denoted by reference numeral 7 in FIG. Although not shown in the drawing, or not shown, a communication groove having a straight shape, a curved shape, a screw shape, or the like which should form the opening is provided, and air can be ventilated from the reference numeral 8 between the inner and outer layers of the body portion that are easily peeled off. Further, it is also possible to provide a circumferential step that abuts against each other between the inner and outer layers of the head, and open and close the circumferential vent hole by vertically engaging and separating the step. or,
Vents drilled in the head wall of the outer layer are also possible.

At the upper end of the outer layer of the container mouth, reference numeral 3c in FIG.
Further, as shown in 3d, the convex portion of the reference numeral 3b of the inner layer is fitted only with the reference numeral 3d when the ventilation hole is opened, and is closely fitted with the reference numeral 3c when the ventilation hole is closed. The inner layer outer protrusion of reference numeral 3b is continuous with the inner layer outer surface protrusion shown by reference numeral 6 of FIG. 7, and interlayer ventilation is alternately performed with the rotation of the inner layer. 3d is fitted to prevent excessive rotation of the inner layer.

In FIG. 6, reference numeral 10 is a valve body for preventing air intake into the container, which is adhered to the inner layer flange portion. The semicircle of the container mouth is fixed, and the remaining semicircle is a movable part. A movable groove 12 is provided in the diametrical direction, so that the filling material for the container can be easily poured out and the air intake space is not required as in the conventional case. Therefore, the semicircle can be closed without any problem, depending on the nature of the filling material. It is possible to adjust the pouring amount by increasing or decreasing the fixed part. It is also possible to provide a falling pressure receiving piece for the filling below the movable portion of the valve element to immediately seal the valve element.

When fitting the inner and outer layer parisons, it is necessary to evacuate the layers, and the inner surface of the parison as the inner layer and / or the inner surface of the parison as the outer layer extends from the mouth portion to the bottom portion as indicated by reference numeral 7a in FIG. The inner and outer layer parisons are fitted by providing a gap formed by the air vent communication groove having a high and low slope. It should be noted that air bleeding is possible even if the inner layer body portion is elliptical or has a different diameter instead of the air bleeding communicating groove, and can be freely selected within a range that does not impair the formation of the container wall such as stretching and residual air between layers. The ventilation groove in the body disappears as it stretches, and becomes the interlayer ventilation groove shown by reference numeral 7 in the head after molding.

Since the inner layer of the multi-layer molded container of the present invention has a structure that naturally shrinks with the use of the filling material, the inner layer flange of reference numeral 3a is provided at the container opening portion, and the inner layer of reference numeral 3b is provided when there is no flange. When the flange portion does not have rigidity at the outer protruding portion, the flange portion is prevented from falling and dropping by joining with the flange joining ring or the inner lid. Further, in the bottom of the container, the inner and outer layers are joined by interposing an adhesive layer therebetween, and in the case of a single parison integrally molded, the inner and outer layers are joined in advance at the time of molding to prevent the inner layer from falling off.

In the method for producing a multi-layer molded container of the present invention, which comprises a thermoplastic resin as a constituent layer and is easily peeled off, a thermoplastic resin such as polyester, polyvinyl chloride, polypropylene, polyacrylonitrile or polystyrene, which is an outer layer after molding, is formed. The bottomed parison shown by the reference numeral 1 of the upper end opening and the polymerization and multilayer of polyester or polyester and another resin, or the upper layer of the upper end opening which is an inner layer made of a constituent layer of thermoplastic resin not containing polyester A composite bottomed parison can be obtained by molding the bottomed parison with one and / or both of them having a function of generating a space capable of degassing layers and then fitting the parison. Examples of the present invention include:
Composite parison that is fitted after injection molding of polyethylene terephthalate for both inner and outer layers. A multi-layer container was obtained by biaxial stretching by using a parison as an outer layer made of polyethylene terephthalate and a parison as an inner layer made of polyester obtained by polymerizing polyethylene terephthalate with 20% polyethylene isophthalate after injection molding. .

In the biaxially stretch-blow molding of the parison in the first step 1, 100 parts of the outer part of the parison other than the head part are used.
Heated to a uniform temperature of ℃, the part other than the head of the parison as the inner layer is 120 ℃ for the bottom, and 1 for the bottom of the head.
The inner and outer layer parisons are heated while being heated to a vertical inclination temperature of up to 00 ° C., and fitted together while degassing the layers. Next, the split mold upper members shown in FIG. 4 are held by the reference numerals 21a and 21b and moved to a biaxial stretch blow molding zone, and then the split mold lower members 22a and 22b.
Is closed to form a cavity 20 therein. Next, the stretch bar support member 14 shown in FIG. 5 descends to come into close contact with the inner surface of the inner layer of the head, and then the stretch bar 15 descends to contact the bottom of the composite parison and extend the composite parison. Simultaneously with the lowering of the stretching rod, the fluid is blown from the fluid passage indicated by reference numeral 16 and the parison is stretched in the axial direction and in the circumferential direction at the same time. Due to the pressure of the injected fluid, the inner layer parison is stretched from the high heat distribution portion at different stretching speeds and stretched to make immediate contact with the outer layer, and interlayer residual air when the parison is fitted is discharged from the head ventilation holes. Further, the air-bleeding communication groove of the body portion disappears as it is stretched, and the groove at the lower end of the head remains substantially depending on the stretching ratio. Further, in the inner-outer layer composite portion of the head, which is an unstretched portion, the inner layer can be rotated or moved up and down by an external force in the outer layer.

In the biaxially stretch blow molding of the parison in the second stage before the second stage, in addition to the same method as in the first stage, the resin temperature characteristic of the inner layer can be stretched at a temperature lower than the temperature of the outer layer. Taking advantage of the fact that the layers are heated to a gradient temperature and the stretching speed is different even at the same temperature as the inner and outer layers, the layers are sequentially degassed while degassing the layers. The inner layer of the head can be rotated or moved up and down by an external force in the outer layer as in the previous stage.

Next, in the composite parison of the present invention, which is a biaxially stretched and easily peelable multi-layer container, the composite parison other than the above-mentioned method is required, for example, by rapidly cooling a composite tubular pipe by coextrusion to form the container. After cutting into various lengths, both ends are reheated, and one end can rotate or vertically move the inner layer with which the one end is closely attached to create an interlayer vent hole. From the inner and / or outer mouth to the lower end of the head. A composite parison can be obtained by providing a protrusion or an intermittent male screw which communicates with, and a flange portion if necessary, and making the other end bottom by compression molding. In this composite parison, there is no need for degassing between layers, and it is possible to easily form multiple layers of inner layers. Furthermore, since a highly gas-barrier resin such as ethylene or vinyl alcohol can be easily used, the parison to be the inner layer is manufactured by this method and is fitted with the parison to be the outer layer formed by injection molding or extrusion molding. By carrying out biaxial stretch blow molding by the above-mentioned method, a multi-layer molded container having high rigidity, transparency, gas barrier property and easy peeling between layers can be obtained.

In the biaxial stretching blow of each parison described above, the strength of the container is enhanced and the shrinkability is improved by stretching the shoulder portion of the container.
When a flexible resin is used for the parison head as the inner layer, a support member having an inner layer gripping mechanism is added to the outer periphery of the stretch rod support member shown by reference numeral 14 in FIG. 5 to grip the inner layer partially or entirely. By biaxially stretching blow molding, the stretching ratio of the shoulder portion of the container is increased, and the strength, shrinkability and transparency are improved. Further, the inner layer gripping mechanism allows the flexible resin to release the downward attraction force due to the biaxial stretching in the head portion, so that the accuracy of the head portion of the inner layer can be maintained.

In the multi-layered container of the present invention, the layers are aerated in proportion to the amount of the filling material used in the container, and the inner layer shrinks vertically along the center line of the container, and the inner layer is suspended inside the container. In the section, the inner flange portion of the reference numeral 3a, the reference numeral 3
The inner layer outer convex portion of b, the flange joint ring, and the head are prevented from falling and dropping by an intermittent male screw or the like, and at the bottom of the container, an adhesive resin is applied or applied when the inner and outer parisons of reference numerals 1 and 2 are fitted. After the bottom forming, the bottom inner and outer layers are joined together. When joining the bottom part, it is possible to alternate the inner and outer layers at the time of compression molding of the parison, and it is also possible to pierce the bottom part of the outer layer parison and fit the sprue of the inner layer parison to connect by compression molding. Is.

As described above, the feature of the biaxially stretched interlayer easily peelable multilayer container of the present invention is that the sucked outside air is separated and stored, so that the container filling material does not come into contact with the outside air as much as possible. Where it is. That is, as shown in FIG. 1, when the content substance filled in the inner layer of reference numeral 2 is taken out, as shown in FIGS. The interlayer ventilation holes are opened, and by the generation of this ventilation function, the outside air corresponding to the extraction volume of the content substance is separated and filled between the inner and outer layers without touching the filled content substance. The vent hole of reference numeral 8 can be arbitrarily opened and closed at various points of time such as production of containers, cleaning, filling of contents, transportation, and sale. While maintaining the same convenience, the protection function can be continued even after opening and opening the stopper. The ventilation hole of the reference numeral 8 of the biaxially stretched multi-layered container of the present invention is automatically or by twisting or pulling up the lid portion with fingers at the stage when the consumer consumes the filling material. Open and close easily in conjunction. The inner layer of the reference numeral 2 stretched by interlayer ventilation from the ventilation holes shrinks following the decrease of the filler, while the outer layer of the stretched reference numeral 1 always maintains its original shape due to its elasticity.
It will be restored. Also, the outer protrusion of the inner flange of reference numeral 13, the partial extension of the outer protrusion of reference numeral 3b or 3e, the outer protrusion of the flange joint ring and the protrusion provided on the inner circumference of the fitting lid are in contact with each other. By opening and / or closing by opening and / or closing, it is possible to freely select the opening and closing of the ventilation hole by contacting or joining, and it can be used properly according to the viscosity of the filling material and the convenience of pouring by intake and exhaust. Is. Further, in the case where the viscosity of the container filling is accompanied by intake air in the inner layer after use, the filling shut-off valve shown by reference numeral 10 or a pouring amount limiting middle lid without a movable part is provided at the pouring outlet of the filling portion. Will be protected from outside air contact. Furthermore, in the case of thermoplastic resins such as polyester, polyvinyl chloride, polypropylene, polyacrylonitrile, polystyrene, etc., biaxially stretch blow molding dramatically increases the strength of the container and the transparency of transparent resins. Has been found to improve further.

[0041]

INDUSTRIAL APPLICABILITY As described above, the biaxially stretched multilayer container of the present invention is provided with a thermoplastic resin in which the interface between the inner and outer layers is in an easily peelable state, or even if the thermoplastic resin is between the resins, the condition is set below the melting point. The interface becomes easily peeled by adopting, and the inner layer has film-like flexibility by stretching, and the unstretched part of the container head is rotated by external force from fingers or fitting lid part. Alternatively, the interlayer ventilation holes can be opened and closed by moving up and down. Delamination clearly progresses when the inner layer of the head rotates or moves up and down, and the outside air corresponding to the amount of the container filling material is separated and filled between the inner and outer layers without touching the filling. In this way, the container filling material can be continuously protected from the external environment even after opening and opening until the end of use. In addition, protection of the filling substance is further improved by providing an intake cutoff valve or a lid for adjusting the pouring amount at the pouring outlet, and the filling substance of the container is consistently exposed to the outside air even after opening and unsealing. Therefore, the quality can be maintained without being subjected to the conventional oxidation, moisture absorption, deterioration, diffusion, dew condensation, etc. that accompany intake from the mouth. Furthermore, since the vents and spouts are concentrated on the head, hygiene at each stage of production, distribution, and consumption can be obtained as before, and the lid can be simply fitted. The filling workability before fitting the lid can be obtained as in the conventional case. In terms of the appearance of the container, the original shape is always maintained and restored regardless of the increase or decrease of the filling substance, so that it is possible to maintain a constant shape despite the shrinkage of the inner layer that adheres to the filling in the container. is there. The vent hole of the multi-layer container of the present invention is opened or closed or communicated by the rotation or vertical movement of the inner layer of the mouth portion or the joined body thereof, and the timing of the rotation or vertical movement depends on the viscosity of the container filling material and / or the convenience of pouring. It can be freely selected, and the protection of the contents and the air permeability between layers can be further improved by using the mouth valve body or the lid for adjusting the pouring amount in combination.

[Brief description of drawings]

FIG. 1 is a central longitudinal side view showing an embodiment of a multilayer molded container according to the present invention.

FIG. 2 is a central longitudinal side view showing an embodiment of a bottomed parison having an upper end opening serving as an outer layer of the multilayer molded container of the present invention.

FIG. 3 is a central longitudinal side view showing an embodiment of a bottomed parison having an upper end opening which is an inner layer of the multilayer molded container of the present invention.

FIG. 4 is a central longitudinal side view showing an embodiment when the composite parison of the multilayer molded container of the present invention is installed in a mold.

FIG. 5 is a central longitudinal side view showing an embodiment of the multilayer molded container of the present invention during biaxial stretch blow molding.

FIG. 6 is an enlarged front view showing an embodiment of the multilayer molded container according to the present invention when a vent hole is opened in the head.

FIG. 7 is the head II of FIG. 6 of the multilayer molded container of the present invention.
FIG.

[Explanation of symbols]

 1 Outer Layer 2 Inner Layer 3a Inner Layer Flange 3b Inner Layer Flange Outer Convex 3c Mouth Outer Layer Recessed 3d Mouth Outer Layer Over-rotation Prevention Recess 3e Mouth Inner Layer Over-rotation Prevention Convex 5 Outlet 6 Head Inner Layer Protrusion 7 Head Interlayer void 7a Interlayer air bleed groove 8 Vent hole 10 Valve body 11 Container body 12 Joint part of valve body movable part 13 Inner layer flange outward protrusion 14 Stretch rod support member 15 Stretch rod 16 Fluid passage 17 Male screw 18 Collar Part 20 Cavity 21a Split mold upper member 21b Split mold upper member 22a Split mold lower member 23b Split mold lower member

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area B29L 24:00 4F

Claims (14)

[Claims] 1. An easily peelable multi-layered molding container having a thermoplastic resin as a constituent layer, which is an outer layer of an upper end opening made of a thermoplastic resin such as polyester, polyvinyl chloride, polypropylene, polyacrylonitrile, or polystyrene. The bottom parison and the bottomed parison, which is the inner layer of the opening at the upper end and is composed of a polyester or a polymer layer of polyester or other thermoplastic resin or a multilayer or a constituent layer of a thermoplastic resin not containing polyester, is molded and then fitted together. A parison or a bottomed parison with an integrally formed upper end opening in which the inner and outer layers are in close contact is formed into a multi-layer molded container by the biaxial stretching blow method, and the inner layer of the head after molding is rotated or moved up and down in the outer layer. A multi-layer molded container characterized by opening and closing the interlayer ventilation hole when moved. 2. In the container head, the inner or outer layer is provided with a straight or intermittent screw-shaped groove to be an air gap or an air gap that penetrates from the outer end of the mouth or the lower part of the mouth to the lower end of the head. The multi-layered molded container according to claim 1, which is capable of communicating with the ventilation holes of the head or head wall. 3. The container head, wherein a circumferential step is provided on the outer surface of the inner layer and the inner surface of the outer layer, and the circumferential vent hole is opened and closed by vertically engaging the step. The multilayer molded container described. 4. At the mouth of the container, the upper concave portion of the outer layer and the convex portion of the inner layer or the lower portion of the inner layer flange are fitted to each other to prevent the inner layer from over-rotating and to communicate with the void below the uneven portion as the inner layer rotates. The multi-layer molded container according to claim 1, wherein the vent hole is opened and closed. 5. At the mouth of the container, there is provided a valve body or a pouring amount adjusting inner lid for preventing air intake into the container by adhering or fitting an inner layer or an inner layer flange or a fixing ring adhered to the inner layer portion. The multilayer molded container according to claim 1, wherein 6. The outer surface of the parison as the inner layer and / or the inner surface of the parison as the outer layer is provided with an air-bleeding continuous groove having a high and low slope from the mouth to the bottom, and the body is stretched after stretching. The multi-layer molded container according to claim 1, wherein the multi-layered molded container is eliminated by the above and becomes a ventilation groove on the head. 7. The inner layer outer protruding portion or the inner layer flange or the ring for flange joining is at the container mouth portion at the outer layer end portion or the upper end of the outer layer flange, and at the container bottom portion with an adhesive layer between the inner and outer layers, or parison molding. 2. The multilayer molded container according to claim 1, wherein the inner layer sprue in the outer layer hole is sometimes crushed or the bottom portion is folded to prevent the inner layer from falling off after molding. 8. At the mouth of the container, a protrusion is provided on the outer periphery of the inner layer outer protrusion, the inner layer flange or the flange joint ring, and abuts on the protrusion provided on the inner periphery of the lid.
The multi-layer molded container according to claim 1, wherein the vent hole can be automatically opened and closed by rotating or vertically moving the inner layer when the cap is opened or closed. 9. A ring having a vent hole or a vent valve body or a sealing ring body is attached or applied between the inner and outer layers of the mouth of the parison to impart sealing property and interlayer breathability when closing and / or opening after molding. The multi-layer molded container according to claim 1, wherein 10. An easily peelable multi-layered molding container having a thermoplastic resin as a constituent layer, which is made of a thermoplastic resin such as polyester, polyvinyl chloride, polypropylene, polyacrylonitrile, or polystyrene, which is an outer layer after molding, and has an upper end opening. The bottomed parison at the upper end opening, which is an inner layer consisting of a polymerized layer of polyester or polyester and other resin or a multilayer or a constituent layer of a thermoplastic resin not containing polyester, is delaminated on one and / or both sides. A composite bottomed parison that was fitted after being formed with an air-permeable space,
Alternatively, a step of forming a bottomed parison with an integrally formed upper end opening in which the inner and outer layers are in close contact with each other, and heating the parison to a proper temperature, installing this in a split mold, and heading by a blow molding method. A method for producing a biaxially stretched multi-layer molded container, characterized in that the other parts are biaxially stretched to form a container wall, and the inner layer can be rotated or moved up and down in the unstretched head outer layer. 11. The container head and the lower end of the head to the shoulder portion, the air vent groove of the unstretched portion of the inner layer in the head communicates with the vent hole of the post-molding portion, and the stretching ratio from the lower end of the head to the shoulder portion. 11. The method for producing a multi-layer molded container according to claim 10, characterized in that, in a region having a low degree of expansion, the peeling strength associated with rotation of the inner layer is increased by leaving substantial unevenness while adhering to the inner surface of the outer layer according to the stretching ratio. . 12. An inner layer parison and / or an outer layer parison is heated at a stretching temperature from a bottom portion to a head portion in the bottom portion and the lower portion is high in the upper portion and is inclined in a low temperature at the upper portion, and the interlayer degassing is performed by utilizing a difference in stretching speed. 11. The method according to claim 10,
A method for producing the multilayer molded container described. 13. When the inner and outer layer parisons are fitted, an adhesive resin is applied to the outer surface bottom of the inner layer or the inner surface bottom of the outer layer, or the parison bottom is joined and the inner and outer layers are joined at the container bottom after stretch molding. The method for producing a multi-layer molded container according to claim 10, wherein the multi-layer molded container is combined. 14. A grasping tool inserted at the lower end of the head that does not impair the interlayer ventilation groove from the mouth of the parison as the inner layer and projects outward to maintain the interlayer venting function or airtightness according to the parison. The method for producing a multilayer molded container according to claim 10, wherein the downward attraction to the upper end of the head due to the stretching is canceled while the stretching ratio of the shoulder portion can be adjusted according to the necessity of the function of the container.