JPH11286077A - Packaging material covered with functional resin and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a function such as an antifouling properties, low adsorptivity, alkali resistant cleanability or the like by covering a surface with a functional resin layer. SOLUTION: Either an inner surface or an outer surface or both surfaces of a container is covered with a functional resin layer. As the functional resin, a silicone or fluorine resin having an alkali resistant cleanability, low adsorptivity, antifouling properties, a liquid crystal polymer having an alkali resistant cleanability, low adsorptivity, gas barrier properties, a polyolefin resin or a resin such as a polyethylene naphthalate having an alkali resistant cleanability is used. They are laminated to incorporate a function such as the anti-fouling properties, alkali resistant cleanability, low adsorptivity or the like in the container. Since the functional improvement of the container is different depending upon the resin to be formed, characteristics of the resin are utilized to design the container. Thus, the function such as the anti-fouling properties, alkali resistant cleanability, low adsorptivity or the like can be simply incorporated in the container at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a returnable plastic container, and more particularly to a container which is reused by washing with alkali after use.

[0002]

2. Description of the Related Art Generally, glass bottles are used as returnable containers. However, use of plastic containers has been considered for reasons such as heavy weight, breakage and danger.

In addition, PET bottles are generally used as plastic containers for many beverages such as carbonated beverages in terms of transparency, barrier properties, and internal pressure resistance of carbonated beverages.

[0004] When reused as a returnable container, the PET bottle is not suitable for such a field because the PET resin is hydrolyzed in an alkali washing step, resulting in a decrease in strength and discoloration.

[0005] In order to solve such a problem, a method of coating the surface of a PET bottle by a CVD method or the like is known, but a manufacturing technique has not yet been established.

[0006]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a packaging material having functions such as antifouling property, low adsorption property, and alkali washing resistance.

[0007]

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and the invention of claim 1 is a packaging material whose surface is covered with a functional resin layer. Claim 2
The invention according to claim 1 is the packaging material according to claim 1, wherein the functional resin layer is provided on an inner surface and an outer surface. A third aspect of the present invention is the packaging material according to the first aspect, wherein the functional resin layer is provided on an inner surface. According to a fourth aspect of the present invention, there is provided the packaging material according to the first aspect, wherein the functional resin layer is provided on an outer surface. In the invention according to claim 5, the functional resin layer has a thickness of 5%.
The packaging material covered with the functional resin layer according to any one of claims 1 to 4, wherein the thickness is 0 μm or less.
The invention according to claim 6 is the packaging material coated with the functional resin layer according to any one of claims 1 to 4, wherein the thickness of the functional resin layer is 5 μm or less. Claim 7
The packaging according to any one of claims 1 to 6, wherein the functional resin layer is one of a silicone resin and a fluorine resin. Material. The invention according to claim 8 is the packaging material covered with any one of the functional resin layers according to any one of claims 1 to 6, wherein the functional resin layer is a liquid crystal polymer. According to a ninth aspect of the present invention, the functional resin layer is any one of a polyethylene terephthalate-based resin and a polyolefin-based resin. It is a coated packaging material. According to a tenth aspect of the present invention, there is provided the packaging material according to any one of the first to ninth aspects, wherein the packaging material is a stretch blow molded product and is covered with a functional resin layer. An eleventh aspect of the present invention is the packaging material according to any one of the first to ninth aspects, wherein the packaging material is an injection molded product and is covered with a functional resin layer. A twelfth aspect of the present invention is the packaging material according to any one of the first to ninth aspects, wherein the packaging material is a vacuum molded product and is covered with a functional resin layer. According to a thirteenth aspect of the present invention, there is provided the packaging material according to any one of the first to ninth aspects, wherein the packaging material is a compressed air molded product and is covered with a functional resin layer. The invention according to claim 14 is characterized in that no adhesive resin or adhesive is present between the resin layer having a function of covering the surface and the resin layer of the core which is the main body of the container. Is a packaging material covered with a functional resin layer. The invention according to claim 15 is to produce a molded product in the shape of a final molded product in which a functional resin layer is formed on an inner surface or an outer surface by extrusion blow molding, and the molded product is formed into a core portion or a cavity of an injection mold. 12. The functional resin according to claim 11, wherein the functional resin is inserted into a part, a core part, and a cavity part so that a functional resin layer is formed on a surface in contact with the mold, and the resin is injection-molded. This is a method for producing a packaging material covered with a layer. According to a sixteenth aspect of the present invention, a test tubular parison having a functional resin layer formed on an inner surface or an outer surface is manufactured by extrusion molding or extrusion blow molding, and the parison is formed into a core portion or a cavity portion of an injection mold. Alternatively, the preform is formed by inserting a resin layer having a function on both surfaces of the core portion and the cavity portion in contact with the mold to form a preform, and the preform is stretch blow-molded. Item 11. A method for producing a packaging material covered with the functional resin layer according to Item 10.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. First, the present invention relates to the inner surface of a container,
Silicone or fluorine resin with alkali-cleaning, low-adsorption, and anti-fouling properties, liquid-crystalline polymer with alkali-cleaning, low-adsorption, and gas-barrier properties By laminating a resin layer of polyolefin resin or polyethylene naphthalate with alkali-cleaning properties, the container has functions such as antifouling property, alkali-cleaning resistance, and low adsorption property. The function of the container is different, and the container can be designed by utilizing the characteristics of the resin. With respect to the resin used in the present invention, the point that the function of the container is improved will be described below. However, any resin can be used as long as it can impart a desired function, and the resin used in the present invention is not limited.

[0009] The characteristics of laminating a fluorine-based resin include hydrophobicity, oleophobicity, non-adhesion, improvement in antifouling property,
Improvements in chemical resistance such as alkali resistance and organic solvent resistance, as well as improvement in low adsorption of contents to containers, etc. can be given.

The characteristics of laminating a silicone-based resin include improvement of antifouling property, improvement of chemical resistance such as improvement of alkali resistance, and improvement of low adsorption of contents to a container. Can be

The characteristics of the lamination of the liquid crystal polymer include gas barrier properties such as oxygen barrier and water vapor barrier, chemical resistance such as alkali resistance, and the like.
For example, it is possible to improve the low adsorptivity of the contents to the container.

Examples of the liquid crystal polymer include those obtained by polycondensation of a lower aliphatic ester of an acyloxy aromatic carboxylic acid and an aromatic diol and an aromatic dicarboxylic acid as main components.

The characteristics of laminating polyethylene naphthalate include gas barrier properties such as oxygen barrier and water vapor barrier, chemical resistance such as alkali resistance, and low adsorption of contents to containers. And so on.

As a characteristic of laminating a polyolefin-based resin, improvement in chemical resistance such as alkali resistance is raised.

The resin that comes to the core layer may be any resin that can be formed and processed, and there are no particular limitations such as polyolefin resins such as PP, polyester resins such as PET and PEN, and polyamide.

In order to adhere the resin of the skin layer covering the surface and the resin of the core layer for the purpose of maintaining strength, an adhesive resin,
An adhesive or the like may be used, and an adhesive resin or an adhesive may not be used from the viewpoint of separation when not in use.

When the adhesive or adhesive resin is not used from the viewpoint of separation when not in use, when it is no longer needed, it can be easily ground by centrifugation or the like to separate the resin and the core of the skin layer easily. The resin in the layers can be separated.

<Production Method 1> A method for producing a container covered with the functional resin of the present invention will be described below by way of example, but the production method is not limited thereto. A test tubular parison having a functional resin layer formed on the inner surface or outer surface by extrusion molding or extrusion blow molding is manufactured.

The parison is inserted into one or both of the core portion and the cavity portion of the injection mold so that a functional resin layer is formed on the surface in contact with the mold, and the stretchable resin is stretchable. To form a stretch blow molding precursor called a preform.

As described above, a thin resin layer can be formed by forming a preform by combining extrusion molding or extrusion blow molding with injection molding. Such a method can be applied not only to preforms but also to general injection molded products. The preform thus formed is stretch blow-molded to obtain a container of the present invention whose surface is covered with a functional resin layer. By stretching blow molding, a thinner resin layer can be formed.

As an example, a manufacturing method characterized by a combination of extrusion molding or extrusion blow molding and injection molding has been described. However, the present invention is not limited to this method, and extrusion molding, extrusion blow molding, injection molding, and stretching. A preform or a final molded product may be manufactured by blow molding alone, or a molten resin may be applied to a container not covered with a resin layer to obtain a final molded product.

<Function> By forming a resin layer having a function on one or both of the inner surface and the outer surface of the container, the container has functions such as antifouling property, alkali washing resistance and low adsorption property. Was able to have. Hereinafter, examples of the present invention will be described.

[0023]

EXAMPLES The container covered with the functional resin of the present invention will be described in detail with reference to examples.

<Example 1> A fluororesin, specifically an ethylene tetrafluoride / perfluoroalkoxyethylene copolymer resin, was used for the outer surface layer by extrusion blow molding, and an adhesive resin of the fluororesin and PET was used for the intermediate layer. A PET tube was extruded into the inner surface layer to produce a test tube-shaped parison. As the thickness of each layer, a fluororesin layer; 500 μm, an adhesive layer;
PET layer: 500 μm, parison having an outer diameter of 25 mm. After the parison was inserted into a mold of an injection mold for producing a preform, a PET resin was injected to obtain a preform made of an outer surface fluororesin. The preform was stretch blow-molded at a plane stretch ratio of about 10 times, and the capacity was 900 ml.
Was obtained. The container thus obtained had a fluororesin layer having a thickness of 50 μm formed on the outer surface of the container, and was excellent in alkali washing resistance, stain resistance and the like. Table 1 shows the results of the alkali washing resistance.

Example 2 A liquid crystal polymer obtained by polymerizing an acyloxy aromatic carboxylic acid, an aromatic dicarboxylic acid, and ethylene diol as main components on an inner surface layer by extrusion blow molding, and an intermediate layer of the liquid crystal polymer and PET on an intermediate layer. A test tube parison was prepared by extruding a PET resin onto the adhesive resin and the outer surface layer. The thickness of each layer is as follows: liquid crystal polymer layer; 10 μm, adhesive layer; 5 μm, PET layer;
And a parison having an inner diameter of 20 mm. Similarly, the outer surface layer is formed by extrusion blow molding;
m, middle layer; adhesive 5 μm, inner layer; PET 500 μm
A test tube parison having an outer shape of 25 mm was prepared. Insert the parison of the inner surface liquid crystal polymer into the core of the injection mold for producing the preform, insert the parison of the outer surface liquid crystal polymer into the mold of the mold for producing the preform, and then inject the PET resin to obtain the preform composed of the inner and outer surface liquid crystal polymer. Was. The preform was stretch blow-molded at an area stretching ratio of about 10 to obtain a circular container having a capacity of 900 ml. The container thus obtained had a liquid crystal polymer layer having a thickness of 5 μm on the outer surface of the container and a thickness of 1 μm on the inner surface, and was excellent in alkali washing resistance, gas barrier properties, adsorptivity and the like.
Table 1 shows the results of alkali cleaning resistance and gas barrier properties.

Example 3 Extrusion molding of an alkyl-modified silicone resin for the inner surface layer, an adhesive resin of the alkyl-modified silicone resin and PET for the intermediate layer, and extrusion of the PET resin for the outer surface layer. Produced. As the thickness of each layer, an alkyl-modified silicone resin layer; 100
μm, adhesive layer; 5 μm, PET layer; 500 μm,
The parison had an inner diameter of 20 mm. Similarly, the outer surface layer is formed by extrusion blow molding;
And PET adhesive 5 μm, inner layer; PET 500 μm,
A test tube parison having an outer shape of 25 mm was prepared. Inserting the parison of the inner surface alkyl-modified silicone resin layer into the core of the injection mold for producing the preform, inserting the parison of the outer surface PP into the mold of the mold for producing the preform, and then injecting the PET resin to the inner surface; the alkyl-modified silicone resin layer , Outer surface;
A preform made of PP was obtained. The preform was stretch blow-molded at a plane stretch ratio of about 10 times to obtain a capacity of 900.
A circular container of ml was obtained. The container thus obtained has a thickness of 50 μm on the outer surface of the container and a thickness of 1 on the inner surface.
An alkyl-modified silicone layer having a thickness of 0 μm was formed. Table 1 shows the results of the alkali washing resistance.

Example 4 Polyethylene naphthalate was extruded on the inner surface layer and PET resin was extruded on the outer surface layer by extrusion blow molding to prepare a test tubular parison. The thickness of each layer is as follows: liquid crystal polymer layer; 50 μm, PET layer;
The parison had a diameter of 0 μm and an inner diameter of 20 mm. Similarly, by extrusion blow molding, an outer surface layer: polyethylene naphthalate 100 μm, an inner layer: PET 500 μm,
A test tube parison having an outer shape of 25 mm was prepared. After inserting the inner polyethylene naphthalate parison into the core of the preform fabrication injection mold and the outer polyethylene naphthalate parison into the mold of the preform fabrication mold,
A PET resin was injected to obtain a preform made of polyethylene naphthalate on the inner and outer surfaces. The preform was stretch blow-molded at a plane stretch ratio of about 10 times, and the capacity was 900 m.
1 circular container was obtained. The container obtained in this way is
A liquid crystal polymer layer having a thickness of 10 μm was formed on the outer surface of the container and a thickness of 5 μm was formed on the inner surface. Table 1 shows the results of alkali cleaning resistance and gas barrier properties.

[0028]

[Table 1]

Example 5 A liquid crystal polymer obtained by polymerizing an acyloxy aromatic carboxylic acid, an aromatic dicarboxylic acid, an aromatic diol, and ethylene diol as main components on an inner surface layer by extrusion blow molding. The PC resin was extruded to produce a cup-shaped molded body. The thickness of each layer is as follows: liquid crystal polymer layer; 5 μm, PC layer; 500 μm
And the molded article had an inner diameter of 70 mm. After inserting the molded product of the inner surface liquid crystal polymer into the core of the injection mold for producing a cup, a PC resin was injected to obtain a cup made of the inner surface liquid crystal polymer having a thickness of 800 μm and a capacity of 80 ml. The cup thus obtained had a liquid crystal polymer layer having a thickness of 5 μm formed on the inner surface of the container, and the inner surface of the container was excellent in alkali washing resistance, gas barrier properties, adsorptivity and the like. In addition, after use, they were pulverized and discarded without reuse. At the time of pulverization, the PC and the liquid crystal polymer layer were easily separated, easily separated into respective resins by a specific gravity separator or the like, and could be recycled. . Table 1 shows the results of alkali cleaning resistance and gas barrier properties.

<Comparative Example 1> A PET single-piece preform was molded using the same preform injection mold as in Example 1, and the preform was stretch blow-molded.
A circular container having a capacity of 900 ml and the same shape as in 2, 3, and 4 was obtained. Table 1 shows the results of the alkali resistance and gas barrier properties of the container.

<Comparative Example 2> A single PC cup was molded using the same injection mold as in Example 5 to obtain a cup having the same shape as in Example 4 and a thickness of 800 μm and a capacity of 80 ml.

[0032]

According to the present invention, a functional resin is laminated on one or both of the inner surface and the outer surface of the container of the present invention, so that the container has functions such as antifouling property, alkali washing resistance, and low adsorption property. Can be easily and inexpensively. In addition, a test tubular parison having a functional resin layer formed on an inner surface or an outer surface is manufactured by extrusion molding or extrusion blow molding, which is the manufacturing method of the present invention, and the parison is formed into a core portion of an injection molding die or Insert one or both of the mold parts so that a functional resin layer is formed on the surface that comes into contact with the mold, and injection-mold stretch-blow moldable resin.
A method of forming a stretch blow molding precursor called a preform and performing stretch blow molding is economical because the resin layer of the surface layer can be formed thin.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B65D 1/09 B65D 1/00 B

Claims (16)

[Claims] 1. A packaging material having a surface coated with a functional resin layer. 2. The packaging material according to claim 1, wherein said functional resin layer is provided on an inner surface and an outer surface. 3. The packaging material according to claim 1, wherein said functional resin layer is provided on an inner surface. 4. The packaging material according to claim 1, wherein the functional resin layer is provided on an outer surface. 5. The packaging material covered with any one of the functional resin layers according to claim 1, wherein the thickness of the functional resin layer is 50 μm or less. 6. The packaging material covered with any one of the functional resin layers according to claim 1, wherein the thickness of the functional resin layer is 5 μm or less. 7. The functional resin layer according to claim 1, wherein the functional resin layer is one of a silicone resin and a fluorine resin. Packaging material. 8. The packaging material covered with any one of the functional resin layers according to claim 1, wherein the functional resin layer is a liquid crystal polymer. 9. The functional resin layer according to claim 1, wherein the functional resin layer is a resin selected from the group consisting of a polyethylene terephthalate resin and a polyolefin resin. Packaging material. 10. The packaging material according to claim 1, wherein the packaging material is a stretch blow molded product and is covered with a functional resin layer. 11. The packaging material according to claim 1, wherein the packaging material is an injection molded product and is covered with a functional resin layer. 12. The packaging material according to claim 1, wherein the packaging material is a vacuum molded product and is covered with a functional resin layer. 13. The packaging material according to claim 1, wherein the packaging material is a compressed air product and is covered with a functional resin layer. 14. An adhesive resin or an adhesive does not exist between a resin layer having a function of covering the surface and a resin layer of a core serving as a main body of a container.
A packaging material covered with the functional resin layer as described above. 15. A molded article in the form of a final molded article in which a functional resin layer is formed on an inner surface or an outer surface by extrusion blow molding, and the molded article is molded into a core or a cavity of an injection mold. The resin is injected into both the core portion and the cavity portion so that a functional resin layer is formed on a surface in contact with the mold, and the resin is injection-molded.
A method for producing a packaging material covered with the functional resin layer as described above. 16. A test tubular parison having a functional resin layer formed on an inner surface or an outer surface by extrusion molding or extrusion blow molding, and the parison is formed into a core portion, a cavity portion or a core portion of an injection mold. A preform is formed by inserting a functional resin layer on a surface that contacts the mold in both the portion and the cavity portion to form a preform, and the preform is stretch blow-molded. 1
0. A method for producing a packaging material covered with the functional resin layer according to 0.