JP5266418B1 - Flexible polyethylene container having a deposited film layer and method for producing the same - Google Patents

Abstract

An object of the present invention is to easily give a decoration having a deposited film layer to a main body of a flexible polyethylene container.
In a flexible polyethylene container, an undercoat layer (13) and a deposited film layer (15) are transparent or semi-transparent on the treated surface of a polyethylene layer (11) having a treated surface (11a) subjected to plasma treatment. A transparent middle coat layer (17) and a transparent or translucent top coat layer (19) are formed in this order. Since the surface of the polyethylene layer is modified by the plasma treatment with oxygen gas and the adhesiveness with the undercoat layer is increased, it is possible to easily decorate with the deposited film layer.
[Selection] Figure 2

Description

  The present invention relates to a flexible polyethylene container having a deposited film layer and a method for producing the same.

  The flexible polyethylene container is widely used as a squeeze container for storing contents such as liquids or gels having relatively high viscosity, such as cosmetics, pharmaceuticals, and foods. In this squeeze container, the contents can be easily pushed out by removing the lid and pushing the body of the container with fingers, and the remaining contents can be sealed as it is when the lid is attached again. However, since the flexible container having such squeeze property is repeatedly deformed and restored every time it is used, the decoration applied to the polyethylene container itself must be able to cope with this change. Don't be.

  On the other hand, among these, the polyethylene container used for housing cosmetics does not have to be merely functional. A good-looking design is required as a product face. Furthermore, for example, design uniformity with a series of products housed in a container different from a polyethylene container such as cream or lipstick contained in a hard resin container is also required.

  Conventionally, it is said that it is difficult to form an undercoat layer on a polyethylene container. Therefore, it has been difficult to form a vapor deposition film layer. For example, there is a method of providing a primer layer between a polyethylene terephthalate (PET) film and a vapor-deposited thin film layer made of the inorganic oxide (for example, Patent Document 1). However, even if this method is applied to a polyethylene container, it is not possible to easily form an undercoat layer and thus a deposited film layer. On the other hand, for example, there is a technique for performing decoration using a transfer film in which a body layer of a flexible container having a squeeze property is laminated with a decorative layer including an adhesive layer, a metal deposition layer, and a protective film made of a synthetic resin. It has been developed (see, for example, Patent Document 2). However, according to the method using a transfer film, there is a problem that the work process becomes complicated because it requires at least the trouble of manufacturing the transfer film foil and the trouble of laminating the transfer film.

JP 2007-301878 A JP 2007-326224 A

  This invention is made | formed in view of such a situation, The flexible polyethylene container which can provide easily the decoration which has a vapor deposition film layer in the main body itself of a flexible polyethylene container, and its manufacturing method For the purpose of provision.

  In order to achieve the above object, the present invention comprises the following arrangement. It should be noted that the definitions of terms used to describe the invention described in any claim are not limited to the differences in the invention category, the description order, etc. Shall also apply.

(Characteristics of the invention of claim 1)
A flexible polyethylene container according to the invention of claim 1 (hereinafter referred to as “container of claim 1” as appropriate) has an undercoat layer and a vapor deposition film on the treated surface of the polyethylene layer having a treated surface that has been plasma treated. A layer, a transparent or translucent middle coat layer, and a transparent or translucent topcoat layer are formed in this order, and a gas barrier layer and another polyethylene layer are formed in this order on the surface of the polyethylene layer opposite to the treated surface. It is characterized by. If it is “colorless or translucent”, it does not matter whether it is colored or colorless.

According to the container of claim 1, by forming the plasma-treated surface, the adhesion (adhesion) of the polyethylene container is improved. As a result, the formation of an undercoat layer, which has been difficult in the prior art, and thus the deposited film layer Can be formed. The gas used for the plasma treatment is, for example, oxygen gas (O ₂ ), nitrogen gas (N ₂ ), air, and other gases such as argon gas (Ar) and helium gas (He) as shown in the examples described later. Can be used alone or in combination. By providing the middle coat layer and the top coat layer, for example, the deposition film layer can be more reliably protected against moisture, chemicals, and the like. By making the top coat layer colored or combining colorless or colored and translucent, the gloss of the deposited film layer itself can be changed to enhance the decorating property. Furthermore, the use range can be expanded by improving gas barrier property. In other words, if the gas barrier property is low, it becomes possible to accommodate an object that cannot be accommodated due to deterioration over time. As described above, the container according to claim 1 can sufficiently cope with, for example, a cosmetic container in which strict performance standards are required.

(Characteristics of the invention described in claim 2 )
The flexible polyethylene container according to the invention of claim 2 (hereinafter referred to as “the container of claim 2 ” as appropriate) is the container of claim 1 , wherein the flexible polyethylene container is a blow molded container or a tether. It is a tube container without eyes.

According to the container of Claim 2 , in addition to the effect of the container of Claim 1 , it becomes a seamless container even if it is any of a blow molded container and a tube container. If there is no joint, the design and decoration of the container can be improved. That is, the unevenness caused by the presence of joints does not look good, such as creating a shade. Furthermore, it is not preferable to print characters, designs, etc. across the irregularities, since the irregularities appear on them as well, which is not preferable because the design is damaged. However, such a problem does not occur if there is no joint.

(Characteristics of Claim 3 )
The flexible polyethylene container according to the invention described in claim 3 (hereinafter, referred to as “the container of claim 3 ” as appropriate) is the container of claim 1 or 2 , wherein the plasma treatment is performed using oxygen gas (O ₂ ). In addition to nitrogen gas (N ₂ ) and air, for example, it is performed using at least one gas selected from argon gas (Ar) and helium gas (He).

According to the container of claim 3 , the advantageous effects of the container of claim 1 or 2 can be obtained by using the gas described above alone or in combination. However, it is not intended to prevent the use of gases other than those described above alone or in combination.

(Feature of the invention of claim 4 )
The method for producing a flexible polyethylene container according to the invention described in claim 4 (hereinafter referred to as “method of claim 4 ” as appropriate) includes the other polyethylene layer in which a gas barrier layer and a polyethylene layer are sequentially formed on one surface. A process of forming a treatment surface by plasma-treating at least the other surface, and an undercoat layer, a vapor deposition film layer, a transparent or translucent middle coat layer, and a transparent or translucent topcoat layer in order on the treatment surface And a step of forming. The gas used for the plasma treatment is, for example, oxygen gas (O ₂ ), nitrogen gas (N ₂ ), air, and other gases such as argon gas (Ar) and helium gas (He) as shown in the examples described later. Can be used alone or in combination.

According to the method of claim 4 , by forming the plasma-treated surface, the adhesion of the polyethylene container is improved. As a result, formation of the undercoat layer, which has been difficult in the prior art, and consequently, the deposited film layer, Middle coat layer, top coat layer, etc. can be formed. By providing the middle coat layer and the top coat layer, for example, the deposition film layer can be more reliably protected against moisture, chemicals, and the like. By making the top coat layer colored or combining colorless or colored and translucent, the gloss of the deposited film layer itself can be changed to enhance the decorating property. Moreover, the use range can be expanded by improving gas barrier property. In other words, if the gas barrier property is low, it becomes possible to accommodate an object that cannot be accommodated due to deterioration over time. As described above, the container according to claim 1 can sufficiently cope with, for example, a cosmetic container in which strict performance standards are required.

(Feature of the invention of claim 5 )
The method for producing a flexible polyethylene container according to the invention described in claim 5 (hereinafter referred to as “method of claim 5 ” as appropriate) is the method of claim 4 , wherein the plasma treatment is performed using oxygen gas (O ₂ ), Nitrogen gas (N ₂ ), argon gas (Ar), helium gas (He), and at least one gas selected from the atmosphere.

According to the method of Claim 5, the effect of the method of Claim 4 can obtain a favorable result by using the above-mentioned gas alone or in combination. However, it is not intended to prevent the use of gases other than those described above alone or in combination.

  ADVANTAGE OF THE INVENTION According to this invention, the flexible polyethylene container which can provide easily the decoration which has a vapor deposition film layer directly on the main body of a flexible polyethylene container can be provided. As a result, the above-described flexible polyethylene container can be suitably used for, for example, a cosmetic container that requires particularly strict performance standards.

It is a schematic plan view of the polyethylene container which showed the cover part with the virtual line. It is sectional drawing which shows the laminated structure of a container main body. It is sectional drawing which shows the modification of laminated structure. It is a chart which shows the conditions of plasma processing. It is a graph which shows the reference | standard for evaluating the adhesiveness of a vapor deposition film layer. It is a graph which shows the evaluation result of Examples 1-4. It is a graph which shows the evaluation result of a comparative example.

  Next, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment” as appropriate) will be described with reference to the drawings. In addition, in this embodiment, although the container for cosmetics with the high demand of a flexible polyethylene container is assumed, it differs in the structure of a container, and a manufacturing method only by a different container also about a pharmaceutical, a foodstuff, etc.

(Structure of polyethylene container)
FIG. 1 shows a flexible polyethylene container (hereinafter referred to as “poly container” as appropriate) according to the present embodiment. Here, the poly container 1 is, for example, a tube container containing a cream among cosmetics. In FIG. 1, a polycontainer 1 basically comprises a flexible polyethylene container body 3, an extrusion port 5 of the container body 3, and a lid body 7. A female screw (not shown) corresponding to a male screw portion 5 a formed on the outer periphery of the extrusion port 5 is formed inside the lid body 7, and this female screw is screwed into the male screw portion 5 a of the extrusion port 5. Thus, the contents can be sealed. On the other hand, the contents can be pushed out by removing the lid 7 and pressing the trunk of the container body 3 with a finger. In addition, although not shown in figure, it replaces with the extrusion port 5 and the cover body 7, and does not prevent adoption of the hinge cap which has these functions and can be opened and closed, and other various cover bodies.

  In this embodiment, the tube used as the container main body 3 is manufactured by the extrusion laminating method. The thickness of the body part of the container body 3 is around 0.4 mm. For example, the thickness may be appropriately changed from the viewpoint of the viscosity and barrier properties of the cosmetic. As shown in FIG. 2, the container body 3 includes polyethylene (PE) layers 11 and 23 each having a thickness of, for example, 0.160 mm and 0.187 mm, and, for example, ethylene having a thickness of 0.029 mm, for example. A gas barrier layer 21 made of a material such as vinyl alcohol copolymer (EVOH) is laminated. Next, the shoulder 6 including the extrusion port 5 is integrated with one end of the container body 3 by insert molding. The other end of the tube remains in an open state (not shown in FIG. 1), but this is performed by performing the following laminating process to fill the contents, and then using a dedicated mold or jig (not shown) ) Etc. to heat-seal and close. In addition, there is thermal fusion using ultrasonic waves, and the closing method is not questioned. In addition, although the main body container 3 of the present embodiment has a three-layer structure in which the gas barrier layer 21 is laminated between the polyethylene layers 11 and 13, it does not hinder the increase or decrease in the number of layers. That is, although illustration is omitted, a single-layer structure consisting of only a polyethylene layer may be used depending on the application, or a total of three or more polyethylene layers may be formed, and a gas barrier layer may be laminated between each polyethylene layer. If considered unnecessary, the gas barrier layer can be omitted.

(Lamination of container body)
First, plasma processing is performed in the plasma processing apparatus for the entire outer periphery (hereinafter simply referred to as “outer periphery”) excluding the male threaded portion 5 a of the container body 3. This is because the surface of the polyethylene is modified to improve the adhesion with the undercoat layer 13 described below. When the plasma treatment is finished, an undercoat layer 13 (for example, a thickness of 11.90 μm) is laminated on the entire outer periphery of the container body 3. Further, a vapor deposition film layer 15 (for example, thickness 0.05 μm) is formed thereon by discontinuous vapor deposition (In indium), and further, a transparent (or translucent) middle coat layer 17 (for example 6. 80 μm) is formed, and then a transparent (or translucent) top coat layer 19 (for example, a thickness of 7.30 μm) is laminated. In this way, a flexible polyethylene container 1 (container body 3) whose surface is decorated with a metallic feeling can be obtained. The gas used for the plasma treatment is oxygen gas (O ₂ ), nitrogen gas (N ₂ ), air, as well as, for example, argon gas (Ar), helium gas (He), and the like, as shown in the examples described later. Arbitrary mixed gas etc. can be used.

  Since the middle coat 17 and the top coat layer 19 are colorless and transparent, a metallic feeling derived from indium in the vapor deposition coating layer 15 can be observed from the outside of the container body 3. This is in order not to disturb the external observation of the metal feeling. In addition, each site | part shown in FIG. 2 is represented typically, and actual thickness may differ (FIG. 5 is also the same).

  The undercoat layer 13 is made of an undercoat resin composition containing an acrylic resin as a main component. Alternatively, a general undercoat resin composition such as urethane can be used instead. And although the thickness is based also on the raw material to laminate | stack, about 10 micrometers is preferable like this embodiment. In addition, a main component means the component which occupies the majority of the whole, and also means the case where the whole consists only of a main component.

  The vapor deposition film layer 15 can be obtained by performing discontinuous vapor deposition using indium as a metal material as described above. By using indium, it is possible to obtain a high-class metallic feeling, and in combination with discontinuous vapor deposition, even if the container body 3 is repeatedly squeezed, cracks are generated or peeled off. No durable decoration can be realized. For example, tin or gold may be used instead of indium.

  Further, the top coat layer 19 is formed by applying a colorless and transparent acrylic paint, but other top coat paints may be used instead. If necessary, the various coating materials forming the top coat layer 19 may contain a colorant to produce a color tone. In this case, the range of the design and the color tone is further expanded depending on the combination with the metal feeling of the deposited film layer 15. The top coat layer 19 has functions of a protective film such as oxidation prevention of the vapor deposition film layer 15 and prevention of corrosion and wear, and realizes improvement in durability of the container body 3. In order to prevent this, a UV-cutting agent or the like may be added to the above various topcoat paints. The thickness is preferably about 10 μm as an example.

  According to the above laminating process, the conventional two-step process of first transferring and transferring a transfer film including a vapor deposition film layer or the like is unnecessary, and the vapor deposition film is efficiently applied to the surface of the polyethylene container 1 (container body 3). Layer 15 can be formed. In addition, since the top coat layer 19 is transparent, the metal feeling of the deposited film layer 15 can be observed externally. As a result, conventionally, a vapor deposition film layer could not be formed on polyethylene (PE), but it has become possible to create the same or similar appearance as other containers such as PET, PP, and glass. Furthermore, unlike decorating with a transfer film, no deviation or peeling occurs, and a beautiful appearance can be maintained for a long period of time. In addition, since the surface of the polyethylene layer 11 is plasma-treated, the adhesion with the undercoat layer 13 becomes strong, and this allows the container body 3 to follow the bending.

  Therefore, even if the body part of the container body 3 is pushed with the belly of the finger each time it is used and pressure is applied only to that part, the vapor-deposited film layer 15 is not cracked or peeled off. Appearance can be maintained for a long time. Further, since the outermost surface of the container main body 1 is protected by the top coat layer 19, it is possible to prevent the vapor deposition film layer 15 from being scratched, peeled off, and worn, and to have a beautiful appearance and a longer life. The durability of 3 itself can also be enhanced.

  Moreover, although the container main body 3 of this embodiment is a tube container, the blow molded container (blow tube) etc. which were formed by blow molding may be sufficient.

  In addition, although the polyethylene container 1 which concerns on this embodiment is applied to the tube container for cosmetics, the object which gives a metal feeling is not restricted to such a tube container. It can be applied to various types of flexible resin molded products, or molded products in which other members are combined with flexible resin molded products. For example, the present invention can be widely applied to squeeze bottles containing food and drink (mayonnaise, sports drinks, etc.), laminated tubes containing toothpaste and the like.

  Next, examples of the present invention will be described together with comparative examples. However, it goes without saying that the present invention is not limited to these examples. Here, first, a poly container having a three-layer structure was manufactured by an extrusion laminating method. The innermost polyethylene (LDPE) layer had a thickness of 0.187 mm, the outer gas barrier layer had a thickness of around 0.029 mm, and the outer polyethylene layer had a thickness of 0.160 mm. Next, a shoulder including an extrusion port at one end of the container body was integrated by insert molding to obtain a poly container.

(Examples 1-4)
The surface of the polyethylene layer which is the outermost layer of the plastic container was subjected to plasma treatment to form a treated surface. Thereafter, an undercoat layer was formed by applying an undercoat resin composition mainly composed of an acrylic resin to the treated surface. Further, indium was discontinuously deposited on the undercoat layer to form a deposited film layer. A middle coat layer made of urethane-based paint was formed on the deposited film layer. Finally, a top container layer made of an acrylic paint was formed to obtain a plastic container according to each example. There are four types of gases used for the plasma treatment: oxygen gas (O ₂ Example 1), nitrogen gas (N ₂ Example 2), air (Example 3), and argon gas (Ar Example 4). At this time, the thickness of each layer was 11.90 μm for the undercoat layer, 0.05 μm for the deposited film layer, 0.80 μm for the middle coat layer, and 7.30 μm for the topcoat layer. The conditions of the input gas and the like related to the plasma processing are as shown in FIG.

(Comparative example)
FIG. 4 shows a comparative example. The difference between the plastic container according to the comparative example and the plastic container according to Examples 1 to 4 shown in FIG. 2 is that the latter has a middle coat layer that does not exist in the former. For ease of comparison, the same reference numerals as those used in FIG. 2 are used in FIG. The manufacturing method is the same as the manufacturing method according to Examples 1 to 4 except that the middle coat layer is not provided. At this time, the thickness of each layer is not different.

(Adhesion evaluation of plastic containers)
About the Examples 1-4 and the comparative example which were mentioned above, the adhesiveness of the vapor deposition film layer in a plastic container was evaluated. This adhesion evaluation is divided into two types. The first evaluation is an evaluation by the cross-cut method, and the next evaluation is an evaluation performed by the same method as the cross-cut method after the immersion test. The reason why the immersion test is adopted is to determine whether the target plastic container can be used as a cosmetic container to which the strictest usage standards are applied. This is because if it can be used as a cosmetic container, it will be known that it can be used for other purposes (for example, food). Here, in the cross-cut method, a right-angle lattice pattern (25 squares) is cut into the coating film, and the coating film resistance to peeling from the substrate when penetrating to the substrate is divided into six stages of classification 0 to 5 This is an evaluation method and is defined in JIS K5600-5-6 (adhesiveness (cross-cut method)). As shown in FIG. 5, “0 (zero)” is the best for this criterion, and the evaluation becomes worse as the number increases. FIG. 6 shows the evaluation results of Examples 1 to 4, and FIG. 7 shows the evaluation results of the comparative example.

  As is apparent from FIGS. 6 and 7, as long as the initial adhesion state is not performed, all of Examples 1 to 4 (with a middle coat layer) and Comparative example (without a middle coat layer) are classified as 0 ( It was found that the adhesion of the deposited film layer was good regardless of the presence or absence of the middle coat layer. On the other hand, when the immersion test was performed, almost no peeling was observed in Examples 1 to 4, but the adhesiveness was clearly deteriorated in Comparative Examples. From the above, it has been found that any plastic container that has been subjected to plasma treatment and has a middle coat layer can be used as a container for containing any liquid or gel-like contents including cosmetic containers.

  The present invention is suitable for a flexible polyethylene container suitable for containing a liquid or gel-like content such as cosmetics and extruding the content.

DESCRIPTION OF SYMBOLS 1 Poly container 3 Container body 5 Extrusion port 5a Male thread part 6 Shoulder part 7 Cover body 11 Polyethylene layer 11a Processed surface 11b Opposite surface 13 Undercoat layer 15 Deposition film layer 17 Middle coat layer 19 Topcoat layer 21 Gas barrier layer 23 Other polyethylene layer

Claims (5)

An undercoat layer, a vapor deposition film layer, a transparent or translucent middle coat layer, and a transparent or translucent topcoat layer are sequentially formed on the treated surface of the polyethylene layer having a plasma-treated treated surface .
A flexible polyethylene container , wherein a gas barrier layer and another polyethylene layer are sequentially formed on a surface of the polyethylene layer opposite to the treated surface . The flexible polyethylene container according to claim 1 , wherein the flexible polyethylene container is a blow molded container or a seamless tube container. The flexible polyethylene container according to claim 1 or 2 , wherein the plasma treatment is performed using at least one gas selected from oxygen gas, nitrogen gas, argon gas, helium gas, and air. A process of forming a treated surface by plasma-treating the other surface of the other polyethylene layer in which a gas barrier layer and a polyethylene layer are sequentially formed on one surface;
A flexible polyethylene container comprising: an undercoat layer, a vapor deposition film layer, a transparent or semi-transparent middle coat layer, and a transparent or semi-transparent top coat layer sequentially formed on the treated surface. Manufacturing method. The method for producing a flexible polyethylene container according to claim 4 , wherein the plasma treatment is performed using at least one gas selected from oxygen gas, nitrogen gas, argon gas, helium gas, and air. .

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