JP5141205B2 - Decorative plastic containers - Google Patents

Description

  The present invention relates to a decorative plastic container in which a thin film is formed on a surface of a plastic container, for example, a plastic bottle, a plastic cup, a plastic tray or the like in order to impart decorating properties.

  Conventionally, plastic containers are lightweight, easy to use, safe and relatively low in cost, and thus are used in various fields including food and pharmaceutical fields. However, since its shape is three-dimensional, it is relatively weak at providing design features that stimulate consumers' willingness to purchase compared to other packaging materials such as plastic film called paper and soft packaging. Met. Therefore, in order to improve the design of the plastic container, for example, a shrink film pre-printed on the surface of the container is used to heat-fix the body after molding the plastic container, or an ink printed in advance at the same time as the plastic container is molded. A transfer material having a release layer preliminarily printed after molding of a plastic container, a printed pattern layer exhibiting design properties, and an adhesive layer to be bonded to the container has been used. All of these are pre-printed materials that are pasted together, making it difficult to feel unity with the container. This is a technique that is likely to occur.

Furthermore, for the purpose of improving the design of the plastic container, a metal or a metal compound such as gold, silver, copper, aluminum, or chromium is vapor-deposited on the surface of the container (see, for example, Patent Document 1) or the main resin at the time of container molding There is also a method of compounding and kneading and coloring.
However, when metal or a metal compound is vapor-deposited on the surface of the container, mainly physical vapor deposition (PVD), it is extremely difficult to freely control the adhesion and peelability to the plastic container. Met. The reason is that vapor deposition particles having a composition different from that of the plastic container cannot chemically strengthen each other's adhesion. Furthermore, when using a method of compounding with the main resin and kneading and coloring when forming the container, it becomes impossible to separate the decorative substance from the plastic container, so that the applications that can be developed from the viewpoint of recyclability are limited. There is a problem. In addition, the majority of such containers are currently disposed of and disposed of in landfills.

  The present invention for the purpose of simultaneously satisfying the provision of decorating properties and the removal thereof is to solve the above-mentioned problems, and the problem is that it is attached to a plastic container using a preprinted material. When combined, in-mold labels and transfer materials that cannot be easily peeled off are improved so that they can be easily peeled off. When directly deposited on a plastic container, or when compounded with the main resin during container molding and colored. The object of the present invention is to provide a decorative plastic container that is excellent in decorating properties, recyclability and ecology, and is improved so that a decorative substance that cannot be easily peeled and separated can be easily peeled and separated.

That is, according to a first aspect of the present invention, in a plastic container having a thin film formed on the surface, a thin film decorative layer having a high refractive index for imparting decorating properties to the plastic substrate surface of the plastic container is provided. The thin film decoration layer is composed mainly of titanium oxide having a high refractive index of 2.0 or more and another substance having a high refractive index, and has a medium refractive index such as silicon oxide. It is a decorative plastic container characterized by dispersing a substance having it.

Next, in the second invention of the present invention, an easily peelable adhesive layer is formed as a single layer or a plurality of layers between the plastic substrate surface and the thin film decorative layer in order to impart recyclability. it is decorated plastic container mounting serial to the first invention, wherein.

Next, the third invention of the present invention, the peelable adhesive layer of the single layer is a titanium oxide: silicon oxide = 1: 2 composition according to the second invention, wherein it is a single layer of It is a decorative plastic container.

In the fourth invention of the present invention, the plurality of easily peelable adhesive layers are formed by laminating a single layer of silicon oxide and a single layer of titanium oxide: silicon oxide = 1: 2 composition. This is a decorative plastic container according to the second invention.

  The decorative plastic container of the present invention is excellent in the decorative property of the container because a thin film decorative layer having a high refractive index for imparting decorative properties is laminated on the plastic substrate surface by several tens of nm or more. Moreover, since an easily peelable adhesive layer or a plurality of layers can be formed between the plastic substrate surface and the thin film decorative layer, the thin film decorative layer can be easily peeled from the plastic substrate surface. Excellent recyclability and ecology.

  One of the important features of the present invention is to impart excellent decorating properties to the plastic container. For this reason, as shown in FIG. 1, a thin film decoration layer (3) is formed on the surface of a plastic substrate (2) of a plastic container (1). Due to the continuous thin film bonded in the shape, each wavelength of light 400 nm to 800 nm in the visible light region is shortened according to its refractive index, the speed of light is slowed down, the reflectivity is increased accordingly, and it is bonded in an amorphous form. An effect is also added, diffuse reflection becomes strong, and a very excellent decoration effect can be obtained by increasing the brightness.

  In addition, in order to produce this decoration effect, when an amorphous continuous thin film of titanium oxide having a refractive index of 2.0 or more is formed, the required minimum film thickness is effective at several tens of nm or more. Compared to the decorative effect when depositing metal or metal compounds such as gold, silver, copper, aluminum, and chromium on the surface of the container, this film thickness is on the order of ppm in the present invention. On the other hand, there is a big difference in recyclability because the conventional technology is in the order of%. The film thickness of the present invention is at a level where the influence on recyclability is not regarded as a problem.

  Also, in order to enhance the diffuse reflection effect, silicon oxide having a medium refractive index is appropriately dispersed in a three-dimensional sea-island structure in order to enhance the diffuse reflection effect, rather than forming a continuous surface with a continuous film of titanium oxide bonded in an amorphous form. In addition, by using the laminated thin film, it is possible to obtain a very strong brightness peculiar to special processing such as glass faceting.

  Thus, depending on the purpose of decoration, the dispersion state (mixing ratio of the high refractive index material in the three-dimensional sea-island structure) when using a high refractive index material and its film thickness, medium refractive index material in combination, By controlling the film thickness, it is possible to provide a decorative plastic container having an excellent decorative effect.

  Another important feature of the present invention is to provide a decorative plastic container that can be easily peeled off from a thin film decorative layer formed on the surface of a plastic substrate and is excellent in recyclability and ecology. For this reason, as shown in FIG. 2, there is resistance in the acidic and neutral regions between the thin film decorative layer (3) bonded with the high refractive index material in an amorphous form and the surface of the plastic substrate (2). By providing an intermediate easily peelable adhesive layer (4) mainly composed of silicon oxide that is not resistant to cleaning in an alkaline region, it can be easily peeled off from the intermediate easily peelable adhesive layer by alkali cleaning. is there. In addition, as shown in FIG. 2, you may provide a coat layer (5) in the surface of a thin film decoration layer (3), in order to protect a thin film decoration layer and to improve a refractive index.

  In order to bring out the function of the intermediate easily peelable adhesive layer, the composition is silicon oxide with respect to the titanium oxide component 1 for maintaining the adhesive strength with the thin-film decorative layer formed with the continuous thin film of titanium oxide. By blending the physical component at a ratio of 2, the silicon oxide component having an effect of keeping the adhesive strength with the plastic substrate surface as the other side from the acidic side to the neutral side and peeling off on the alkaline side was increased. It is blended.

  Furthermore, in order for the intermediate easily peelable adhesive layer to be easily peeled off on the alkaline side, the intermediate layer is multilayered so that the adhesion to the plastic substrate surface is extremely deteriorated on the alkaline side, but only a silicon oxide component layer. As a result, the function of the easily peelable adhesive layer can be reliably expressed.

  In this way, it is possible to provide a decorative plastic container excellent in recyclability and ecology by making it possible to easily peel the thin film decorative layer from the surface of the plastic substrate by washing in an alkaline region. It becomes.

  In addition, the method of providing the decorating property, recyclability, and ecology of the present invention described above can be applied to plastic molded products used for home appliances and electronic parts.

  First, the specific Example of the decorative plastic container of this invention which provided the decorating property to the plastic container is demonstrated.

In the actual film formation process, a dipping coat which is one of wet coatings was used. 1,3-butanediol and isopropyl alcohol IPA were added and dissolved in titanium tetraisopropoxide TTIP (Ti (Oi-pr) ₄ ), and then nitric acid was appropriately added as an acid catalyst for hydrolysis. This solution was dried at a low temperature of 40 ° C. after dipping coating in which the outer surface of the PET bottle appropriately surface-treated was immersed. Furthermore, a UV lamp was used as a process for decomposing the hydrolyzed sol-gel film. The PET bottle on which the dried sol-gel film was laminated was irradiated with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes and 60 minutes. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed.

<Example 1>
First, 28 g of titanium tetraisopropoxide TTIP (Ti (O-i-pr) ₄ ) was hydrolyzed by adding 500 g of 1,3-butanediol, 35 ml of isopropyl alcohol IPA, 15 ml of 1N HNO ₃ nitrate and 15 ml of 60% nitric acid. A sol solution was obtained. After dipping coating in which the outer surface of the PET bottle whose surface wettability was increased by oxygen plasma treatment was immersed in this sol solution, it was dried at a low temperature of 40 ° C. to obtain a gel film. Furthermore, the decomposition state was visually confirmed by irradiating with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes for 60 minutes from the outside of the PET bottle on which the gel film was laminated. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed.

<Example 2>
First, sol liquid obtained by adding 500 g of 1,3-butanediol, 525 ml of isopropyl alcohol IPA, 15 ml of 1N HNO ₃ nitrate to 28 g of titanium tetraisopropoxide TTIP (Ti (O-i-pr) ₄ ) to obtain a sol solution. It was. After dipping coating in which the outer surface of the PET bottle whose surface wettability was increased by oxygen plasma treatment was immersed in this sol solution, it was dried at a low temperature of 40 ° C. to obtain a gel film. Furthermore, the decomposition state was visually confirmed by irradiating with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes for 60 minutes from the outside of the PET bottle on which the gel film was laminated. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed.

<Example 3>
First, sol liquid obtained by adding 250 g of 1,3-butanediol, 175 ml of isopropyl alcohol IPA, and 15 ml of 1N nitric acid HNO _{3 to} 28 g of titanium tetraisopropoxide TTIP (Ti (Oi-pr) ₄ ) is obtained. It was. After dipping coating in which the outer surface of the PET bottle whose surface wettability was increased by oxygen plasma treatment was immersed in this sol solution, it was dried at a low temperature of 40 ° C. to obtain a gel film. Furthermore, the decomposition state was visually confirmed by irradiating with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes for 60 minutes from the outside of the PET bottle on which the gel film was laminated. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed.

<Comparative Example 1>
First, 28 g of titanium tetraisopropoxide TTIP (Ti (O-i-pr) ₄ ) was hydrolyzed by adding 500 g of 1,3-butanediol, 35 ml of isopropyl alcohol IPA, 15 ml of 1N HNO ₃ nitrate and 15 ml of 60% nitric acid. A sol solution was obtained. After dipping coating in which the outer surface of the PET bottle whose surface wettability was increased by oxygen plasma treatment was immersed in this sol solution, it was dried at a low temperature of 40 ° C. to obtain a gel film. The xenon excimer UV lamp was heated for about 12 hours at 70 ° C. without decomposing the gel film by irradiation, and the change in the decoration effect was confirmed.

<Comparative example 2>
First, sol liquid obtained by adding 500 g of 1,3-butanediol, 525 ml of isopropyl alcohol IPA, 15 ml of 1N HNO ₃ nitrate to 28 g of titanium tetraisopropoxide TTIP (Ti (O-i-pr) ₄ ) to obtain a sol solution. It was. After dipping coating in which the outer surface of the PET bottle whose surface wettability was increased by oxygen plasma treatment was immersed in this sol solution, it was dried at a low temperature of 40 ° C. to obtain a gel film. The xenon excimer UV lamp was heated for about 12 hours at 70 ° C. without decomposing the gel film by irradiation, and the change in the decoration effect was confirmed.

<Comparative Example 3>
First, sol liquid obtained by adding 250 g of 1,3-butanediol, 175 ml of isopropyl alcohol IPA, and 15 ml of 1N nitric acid HNO _{3 to} 28 g of titanium tetraisopropoxide TTIP (Ti (Oi-pr) ₄ ) is obtained. It was. After dipping coating in which the outer surface of the PET bottle whose surface wettability was increased by oxygen plasma treatment was immersed in this sol solution, it was dried at a low temperature of 40 ° C. to obtain a gel film. The xenon excimer UV lamp was heated for about 12 hours at 70 ° C. without decomposing the gel film by irradiation, and the change in the decoration effect was confirmed.

  About the six types of decorative plastic containers of Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3, the decorative effect was evaluated. The results are shown in Table 1.

表１から、目視による加飾効果が良く得られた条件は、実施例１、２、３のキセノンエキシマＵＶランプ照射を１０分以上照射させ、さらに７０℃で約１２時間加温したものであった。キセノンエキシマＵＶランプ照射を行わなかった条件である比較例１、２、３はいづれもその効果が得られなかった。また、７０℃で約１２時間加温していないものは加温したものほどの効果は得られなかった。

From Table 1, the conditions under which the visual decoration effect was well obtained were those in which the xenon excimer UV lamp irradiation of Examples 1, 2, and 3 was irradiated for 10 minutes or more and further heated at 70 ° C. for about 12 hours. It was. In Comparative Examples 1, 2, and 3, which were conditions in which xenon excimer UV lamp irradiation was not performed, the effect was not obtained. Moreover, what was not heated at 70 degreeC for about 12 hours was not as effective as what was heated.

  Next, specific examples of the decorative plastic container of the present invention in which the decorativeness, recyclability, and ecology are imparted to the plastic container will be described.

In the actual film formation process of the easily peelable adhesive layer on the outer surface of the PET bottle, a dipping coat which is one of wet coatings was used. Tetraethoxysilane TEOS (Si (OC ₂ H ₅ ) ₄ ) was hydrolyzed by adding water, isopropyl alcohol IPA, and hydrochloric acid as an acid catalyst as appropriate. Or the dipping liquid used for the film-forming of the thin film decoration layer shown below is mixed uniformly, and the composition after drying is the main component SiO ₂ of the easily peelable adhesive layer in terms of mole: the main component TiO ₂ of the thin film decoration layer = Prepared to be 2: 1. After dipping coating in which the outer surface of the PET bottle was immersed in this solution, it was dried at 70 ° C.

The film forming process of the next thin film decorative layer used a dipping coat which is one of the wet coatings. 1,3-butanediol and isopropyl alcohol IPA were added and dissolved in titanium tetraisopropoxide TTIP (Ti (Oi-pr) ₄ ), and then nitric acid was appropriately added as an acid catalyst for hydrolysis. After dipping coating in which the outer surface of the PET bottle was immersed in this solution, it was dried at a low temperature of 40 ° C. Furthermore, a UV lamp was used as a process for decomposing the hydrolyzed sol-gel film. The PET bottle on which the dried sol-gel film was laminated was irradiated with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed.

<Example 4>
First, sol solution A was obtained by adding 60 g of water, 1 ml of isopropyl alcohol IPA, and 1 ml of HCl HCl of 0.1N to 21 g of tetraethoxysilane TEOS (Si ₂ OC ₅ H ₄ ) ₄ ). Next, sol which was hydrolyzed by adding 500 g of 1,3-butanediol, 35 ml of isopropyl alcohol IPA, 15 ml of 1N HNO3 nitrate and 15 ml of 60% nitric acid to 28 g of titanium tetraisopropoxide TTIP (TiO-i-pr) ₄ ) Liquid B was obtained. Next, these sol liquid A and sol liquid B were mixed at a molar ratio of 2: 1 to obtain this sol liquid C. Next, the sol solution C was dipped for dipping the outer surface of the PET bottle and then dried at 100 ° C. to obtain a gel film. This was the first layer immediately after the plastic substrate surface. Next, dipping coating in which the outer surface of the PET bottle was immersed in the sol solution B was performed, and then dried at 100 ° C. to obtain a gel film. This was the second layer laminated next to the first layer. Furthermore, the decomposition state was visually confirmed by irradiating with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes for 60 minutes from the outside of the PET bottle on which the gel film was laminated. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed. Finally, it was washed with an alkaline solution (PH9 to 10) for 1 hour, and the change in the decorative effect by visual observation was confirmed.

<Example 5>
First, sol solution A was obtained by adding 60 g of water, 1 ml of isopropyl alcohol IPA, and 1 ml of HCl HCl of 0.1N to 21 g of tetraethoxysilane TEOS (Si ₂ OC ₅ H ₄ ) ₄ ). Next, titanium tetraisopropoxide TTIP (Ti (Oi-pr) 4)
28 g of 1,3-butanediol (500 g), isopropyl alcohol IPA (35 ml), 1N nitric acid HNO3 (15 ml) and 60% nitric acid (15 ml) were hydrolyzed to obtain a sol solution B. Next, these sol liquid A and sol liquid B were mixed at a molar ratio of 2: 1 to obtain this sol liquid C. Next, the sol solution A was dipped for dipping the outer surface of the PET bottle and then dried at 100 ° C. to obtain a gel film. This was the first layer immediately after the plastic substrate surface. Next, the sol solution C was dipped for dipping the outer surface of the PET bottle and then dried at 100 ° C. to obtain a gel film. This was the second layer laminated next to the first layer. Next, the sol solution B was subjected to dipping coating in which the outer surface of the PET bottle was immersed, and then dried at 100 ° C. to obtain a gel film. This was the third layer laminated next to the second layer. Furthermore, the decomposition state was visually confirmed by irradiating with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes for 60 minutes from the outside of the PET bottle on which the gel film was laminated. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed. Finally, it was washed with an alkaline solution (PH9 to 10) for 1 hour, and the change in the decorative effect by visual observation was confirmed.

<Comparative example 4>
First, 28 g of titanium tetraisopropoxide TTIP (Ti (O-i-pr) ₄ ) was hydrolyzed by adding 500 g of 1,3-butanediol, 35 ml of isopropyl alcohol IPA, 15 ml of 1N HNO3 nitrate and 15 ml of 60% nitric acid. Sol solution B was obtained. Next, dipping coating in which the outer surface of the PET bottle was immersed in the sol solution B was performed, and then dried at 100 ° C. to obtain a gel film. This was the first layer. Furthermore, the decomposition state was visually confirmed by irradiating with a xenon excimer UV lamp (172 nm, about 10 mW / cm ² ) for 10 minutes for 60 minutes from the outside of the PET bottle on which the gel film was laminated. Then, it heated for about 12 hours at 70 degreeC, and the change of the decorating effect by visual observation was confirmed. Finally, it was washed with an alkaline solution (PH9 to 10) for 1 hour, and the change in the decorative effect by visual observation was confirmed.

  About the three types of decorative plastic containers of Examples 4 and 5 and Comparative Example 4, the decorative effect after the alkali cleaning was evaluated. The results are shown in Table 2.

表２から、加飾効果のあるＰＥＴボトル外面をアルカリ溶液（ＰＨ９〜１０）で１時間洗浄し、その後の加飾効果の変化を目視確認した。アルカリ溶液洗浄で加飾効果を消すのに効果があった、すなわち薄膜加飾層の剥離ができたのは実施例４，５であり、特に実施例５が効果があった。また、比較例４のように易接着易剥離層が存在しないものはアルカリ洗浄後でも一部、目視で加飾効果が見られることから薄膜加飾層の剥離が不十分であることが判明した。

From Table 2, the outer surface of the PET bottle having a decorative effect was washed with an alkaline solution (PH9 to 10) for 1 hour, and the subsequent change in the decorative effect was visually confirmed. Examples 4 and 5 were effective in eliminating the decoration effect by washing with an alkaline solution, that is, the thin film decoration layer was peeled off, and Example 5 was particularly effective. In addition, it was found that the thin film decorative layer was insufficiently peeled because some decorative effects were visually observed even after alkali washing, as in Comparative Example 4, where there was no easy-adhesion easy-peeling layer. .

It is sectional drawing which shows the structure of the outer wall of the decorative plastic container of one Embodiment of this invention. It is sectional drawing which shows the structure of the outer wall of the decorative plastic container of other one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plastic container 2 ... Plastic base material 3 ... Thin film decoration layer 4 ... Easy peeling adhesive layer 5 ... Coat layer

Claims (4)

In plastic containers thin film is formed on the surface, the plastic base surface of the plastic container, the thin decorative layer having a high refractive index for imparting decorative properties, are stacked several 10nm or more, the thin film decorative The layer is mainly composed of titanium oxide having a high refractive index of 2.0 or more and another substance having a high refractive index, and a substance having a medium refractive index such as silicon oxide is dispersed therein. Decorated plastic container. Between the plastic substrate surface and the thin decorative layer, to impart recyclability, easy peel adhesion layer, characterized in that it is formed single layer or plural layers according to claim 1 Symbol placement pressurized Decorated plastic container. The decorative plastic container according to claim 2, wherein the single-layer easy-release adhesive layer is a single layer having a composition of titanium oxide: silicon oxide = 1: 2. 3. The additive according to claim 2, wherein the plurality of easily peelable adhesive layers are formed by laminating a single layer of silicon oxide and a single layer of titanium oxide: silicon oxide = 1: 2. Decorated plastic container.

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