JPH0987119A - Plastic bottle and parison having antimicrobial function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and inexpensively obtain a plastic bottle and a parison which can always exhibit antimicrobial function in any time when the empty bottles are stored or after the bottle is filled with its content. SOLUTION: As a material for the bottle, is used a thermoplastic resin (such as nylon, polyester or polyimide) containing a powder of a soluble glass eluting an appropriate amount of silver ion into the bottle content. Particularly, the plastic bottle 1 is equipped with a screwed cap 3 and a sealing material 4 made of a thermoplastic resin containing a powder of soluble glass which can leach out an appropriate amount of silver ion into the bottle content is set to the inside of the cap contacting with the opening of the bottle. Parison 5 is also produced by using the same resin. The composition of the antimicrobial solubilizing glass is 40 mole % of B2 O3 , 40 mole % of SiO2 , 15 mole % of Na2 O, 3 mole % of CaO and 2 mole % of Ag2 O.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic bottle having an antibacterial function, and in particular, has a sterilizing function that solves the problem of high cost due to sterilization of empty bottles before filling contents and excessive sterilization of contents. Regarding plastic bottles.

[0002]

2. Description of the Related Art As a conventional resin container containing soluble glass, for example, a soluble glass capable of eluting silver ions in the innermost layer of a multi-layer resin tube described in JP-A-6-172103. There is an antibacterial / antifungal tube in which a soluble glass-containing resin layer obtained by kneading the above powder into a resin is used.

[0003]

However, since such a conventional antibacterial / antifungal tube is composed of a multi-layer resin tube, the manufacturing process is complicated, the cost is high, and the mass consumption is extremely large. There is a problem that the multi-layer resin structure is not practical as a bottle to be used.

On the other hand, the bottle-shaped container, when storing an empty container before filling the contents, particularly when it is hot and humid or when it is manufactured in a hot and humid place, dust in the air enters the container. , In some cases, fungi and mold in the dust propagated in an empty container during transportation and storage.

The present invention has been made in view of such conventional problems, and the manufacturing process is simple and can be manufactured at low cost, and the content of the contents is filled and the antibacterial function is exhibited even when the empty bottle is stored. The purpose is to provide a plastic bottle that can.

[0006]

According to the first aspect of the present invention,
A plastic bottle having an antibacterial function, which is made of a thermoplastic resin containing a soluble glass powder capable of eluting a proper amount of silver ions in the contents, and the invention according to claim 2 is the above-mentioned constitution. In addition, the plastic bottle is a bottle with a screw-in lid, and a thermoplastic resin sealing material having the antibacterial function is provided on the inner surface of the lid in contact with the opening of the bottle. It is what The invention according to claim 3 is a semi-finished bottle product characterized by comprising a thermoplastic resin containing a soluble glass powder capable of eluting an appropriate amount of silver ions in the content of the finished product bottle. It is a parison that is a semi-finished product of a bottle having an antibacterial function.

A plastic bottle having an antibacterial function according to the present invention is, for example, as shown in FIG. 1, a plastic bottle 1 formed of a thermoplastic resin containing powder of soluble glass capable of eluting silver ions. And the opening 2 at the top
The screw-in lid 3 as shown in FIG. The bottom of the screw-in lid 3 is fitted with a sealing material 4 made of a thermoplastic resin having an antibacterial function and containing the same soluble glass powder, so that the contents of the bottle adhered to the back of the lid. Prevents decay and mold. The plastic bottle 1 itself also suppresses the generation of bacteria in the contents due to the elution of silver ions due to the contents and moisture in the air.

The soluble glass capable of eluting silver ions used in the present invention has excellent sterilization ability in a glass composition having a controlled dissolution rate with respect to water in the contents filled in a plastic bottle. A silver ion having an effect of 0.4 to 1.6% by weight (converted to Ag ₂ O) is contained,
It is preferable to grind so that the particle size is 5 to 60 μm. Here, the content of silver ions in the glass is 0.4%
If it is below, it is necessary to add a large amount of soluble glass in the thermoplastic resin in order to impart sufficient antibacterial properties, which not only impairs the moldability and strength of the thermoplastic resin, but also other mechanical properties, and is economical. It is also expensive and inconvenient. Further, when the content of silver ions in the glass is 1.6% or more,
Not only is metallic silver deposited during melting of the fusible glass to damage the furnace, but it is also uneconomical. Furthermore, the grain size is 5
If it is less than μm, the dissolution rate of silver from the resin becomes extremely slow, so it is necessary to add a large amount of soluble glass, and if the particle size is more than 60 μm, it will not be visible when kneading into the thermoplastic resin. There is a risk of impairing the smoothness of the surface of the bottle as well as a scale that may cause process troubles such as clogging.

A plastic bottle is usually molded by blow molding (also called hollow molding or blow molding), and as the molding resin, nylon, polyester (PET),
Any thermoplastic synthetic resin can be used as long as it is used in a flexible container such as polyimide, polyethylene, polypropylene, polyvinyl chloride, or polyvinylidene chloride.

The amount of the soluble glass added to the thermoplastic resin varies depending on the particle size thereof, the type of the thermoplastic resin and the expected antibacterial effect, but is generally 0.3 to 10.0%.
Good results are obtained by adding (wt%). 0.3
%, Sufficient antibacterial properties cannot be obtained, while 10.0%
The above addition may impair the properties of the resin, particularly the moldability.

Furthermore, since the amount of silver ions eluted from a bottle made of a thermoplastic resin containing soluble glass has the greatest effect on the antibacterial property, which is the object of the present invention, the amount was experimentally determined. It was confirmed that it was preferable that the elution rate of silver ions from the inner surface of the bottle was 1 to 500 ng / cm ² / day. If the dissolution rate of silver ions is lower than this range, a sufficient antibacterial effect cannot be obtained. On the contrary, if the dissolution rate of silver ions exceeds this range, more than necessary silver ions are eluted and the sustainability of the effect is reduced. If water containing chlorine, such as tap water, is put in a container, the water may be slightly clouded or the inner surface of the plastic bottle may be discolored due to the reaction between silver and chlorine even if the elution rate of silver ions is properly selected. However, by containing 1% or less of the hydrotalcite compound in the resin, the transparency of the plastic bottle can be further improved, and the transparency of the food can be improved when it is used for food such as drinking water. It is convenient because there is no risk of damage.

The components of the soluble glass used in the present invention include network-forming oxides such as SiO ₂ , B ₂ O ₃ and P ₂ O ₅ , or Na ₂ O, K ₂ O, CaO and Mg.
When it comes into contact with water, the soluble glass dissolves little by little when it comes into contact with water, which consists of network-modified oxides such as O, BaO, Al ₂ O ₃ , TiO ₂ , and ZnO, and elutes silver ions contained in the glass composition. What is done can be used without particular limitation.

In the plastic bottle having an antibacterial function of the present invention, silver ions eluted from the soluble glass-containing thermoplastic resin constituting the bottle exerts an antibacterial effect, so that a mineral water or an emergency product requiring an antibacterial effect is used. It can be widely used in various fields such as foods such as drinking water, milk, beer, jam, marmalade and juice, cosmetics such as hair tonic, hair liquid, after shave lotion and other medical products. And for such applications, plastic bottles are commonly used as screw-on lidded bottles. At that time, if a thermoplastic resin sealing material containing a soluble glass powder capable of eluting silver ions as described above is attached to the surface of the back surface of the lid in contact with the mouth of the bottle, the antibacterial effect can be more effectively exhibited. be able to.

[0014]

EXAMPLES The present invention will now be described in more detail by way of examples. Example 1 B ₂ O ₃ 40 mol%, SiO ₂ 40 mol%, Na ₂
An antibacterial soluble glass having a composition of 15 mol% O, 3 mol% CaO and 2 mol% Ag ₂ O is used in an amount of 5 to 25%.
It was ground to a particle size of μm. Next, this soluble glass powder was added to polyethylene terephthalate (PET) in a weight ratio of 1 ·.
After adding 5% and sufficiently kneading, the injection molding method was used to obtain the results shown in FIG.
The test tube-shaped parison 5 shown in (1) was molded, and a plastic bottle for mineral water having an internal capacity of 2 liters was molded by blow molding using this parison as a raw material.
At the time of molding the parison 5, an annular polycarbonate lid seat 6 having a screw adapted to the screw-in lid 3 is put on the outer periphery of the portion to be the opening 2 of the bottle. Distilled water was put in this bottle, and after 30 days, the pH of the eluate and the elution amount of silver ion of glass as the glass dissolution amount were measured. The pH of the eluate was 8.1 and the elution amount of silver ions was 5.5 ng /
cm ² . As an antibacterial test, E. coli was 10,000
Distilled water present at 0 / ml was added, and the number of viable cells after 24 hours was measured. Viable count is 10 or less / ml after 24 hours
And it decreased significantly.

Example 2 B ₂ O ₃ 60 mol%, SiO ₂ 30 mol%, Na ₂
The antibacterial soluble glass having a composition of O 8 mol% and Ag ₂ O 2 mol% was crushed to a particle size of 10 to 40 μm. Next, 3% by weight of this soluble glass powder was added to polypropylene and mixed well, and a plastic bottle for orange juice having an inner volume of 1 liter was molded by the injection molding method and the blow molding method as in Example 1. did. With respect to this bottle, the pH of the eluate, the amount of silver ion eluted, and the viable cell count of Escherichia coli were measured in the same manner as in Example 1. The pH of the eluate was 7.8, the amount of silver ions eluted was 51 ng / cm ² , and the viable cell count was 10 or less / ml.

[0016]

According to the invention described in claim 1, a soluble glass powder capable of eluting a proper amount of silver ions in water, which is the main component of the contents of the bottle, in the thermoplastic resin constituting the plastic bottle. Since it was made into a bottle by blow molding containing
The manufacturing process is simple and inexpensive, and due to the sterilizing effect of silver ions, it suppresses the growth of various bacteria in the bottle during storage of the empty bottle and after filling the contents, and keeps it extremely clean for a long time. can do.

According to the second aspect of the invention, since the sealing material containing the powder of the soluble glass capable of eluting silver ions is also provided on the surface of the back surface of the screw-in lid which is in contact with the mouth of the bottle. In addition, the antibacterial effect can be more effectively exerted, and the hygiene effect can be further enhanced especially in an emergency such as a disaster.

According to the third aspect of the invention, the semi-finished parison in the plastic bottle manufacturing process contains a soluble glass capable of eluting silver ions. Therefore, the parison is used in a special process. A plastic bottle having an antibacterial function can be easily manufactured without adding.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a plastic bottle according to the present invention.

2 is a cross-sectional view of the screw-on lid of the plastic bottle of FIG.

FIG. 3 is a partially cutaway front view of a parison which is a semi-finished product in the manufacturing process of the plastic bottle of FIG.

[Explanation of symbols]

 1 Plastic bottle 3 Screw-in lid 4 Sealant 5 Parison

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[Procedure amendment]

[Submission date] November 9, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

The present invention has been made in view of such conventional problems, and the manufacturing process is simple and can be manufactured at low cost, and the antibacterial function is exhibited even when the empty bottle is stored and after the contents are filled. The purpose is to provide a plastic bottle that can.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

According to the first aspect of the present invention,
A plastic bottle having an antibacterial function, which is made of a thermoplastic resin containing a soluble glass powder capable of eluting a proper amount of silver ions in the contents, and the invention according to claim 2 is the above-mentioned constitution. In addition, the plastic bottle is a bottle with a screw-on lid, and the opening of the bottle
Elute a suitable amount of silver ions in the content on the inner surface of the lid that is in contact with
Made of thermoplastic resin containing soluble glass powder
The sealing material is provided. The invention as set forth in claim 3 is characterized in that it is made of a thermoplastic resin containing a soluble glass powder capable of eluting an appropriate amount of silver ions in the content of the finished bottle.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

[0014]

EXAMPLES The present invention will now be described in more detail by way of examples. Example 1 B ₂ O ₃ 40 mol%, SiO ₂ 40 mol%, Na ₂ O
The antibacterial soluble glass having a composition of 15 mol%, CaO 3 mol% and Ag ₂ O 2 mol% is 5 to 25 μm.
It was crushed to a particle size of. Next, this soluble glass powder was added to polyethylene terephthalate (PET) in a weight ratio of 1 . 5%
After adding and thoroughly kneading, the test tube parison 5 shown in FIG. 3 is molded by injection molding, and further, a plastic bottle for mineral water having an internal volume of 2 liters is molded by blow molding using this parison as a raw material. did. At the time of molding the parison 5, an annular polycarbonate lid seat 6 having a screw adapted to the screw-on lid 3 is put on the outer periphery of the opening 2 of the bottle. Distilled water was put in this bottle, and after 30 days, the pH of the eluate and the elution amount of silver ion of glass as the glass dissolution amount were measured. The pH of the eluate was 8.1 and the elution amount of silver ions was 5.5 ng / c.
It was m ^2. As an antibacterial test, E. coli was 10,000
The number of viable bacteria after 24 hours was measured by adding distilled water present in the number of cells / ml. The number of viable bacteria is 10 or less / ml after 24 hours,
Significantly reduced.

Claims (3)

[Claims] 1. A plastic bottle having an antibacterial function, comprising a thermoplastic resin containing a soluble glass powder capable of eluting a proper amount of silver ions in the content. 2. The plastic bottle is a bottle with a screw-in lid, and the thermoplastic resin sealing material having the antibacterial function is provided on the inner surface of the lid in contact with the opening of the bottle. The plastic bottle having an antibacterial function according to claim 1. 3. A parison having an antibacterial function, comprising a thermoplastic resin containing a soluble glass powder capable of eluting an appropriate amount of silver ions in the content.