JPH1016158A - Antibacterial biaxially oriented polypropylene film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain high antibacterial effect without impairing the fundamental characteristics of this film by a method wherein an antibacterial layer is prepared by compounding solver-containing crystalline zirconium phosphate with propylene-ethylene copolymer, the percentage of the single polymer of propylene or of ethylene in which is below the specified value. SOLUTION: This antibacterial biaxially oriented polypropylene film is prepared by laminating an inorganic antibacterial layer onto at least one side of a polypropylene base material layer. An antibacterial layer is prepared by compounding silver-containing crystalline zirconium phosphate with propylene- ethylene copolymer, the percentage of the single polymer of propylene or of ethylene in which is below 2.5%. The more the percentage of the ethylene in the copolymer becomes, the better the wettability of the surface of the silver- containing zirconium phosphate particle used as the antibacterial layer with the polypropylene resin becomes, resulting in making the exposure of antibacterial agent to the surface of the film difficult under the state being formed into film and, even when the same quantity of the antibacterial agent, with which the antibacterial properties have been obtained, is compounded, no antibacterial properties of the film becomes impossible to obtain.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【産業上の利用分野】本発明は、抗菌剤として銀含有結
晶質リン酸ジルコニウムを含む二軸延伸ポリプロピレン
（以下ＯＰＰ）フィルムであり、フィルムの基本的性能
を損なわず、高い抗菌効果を効率良く得ることのできる
抗菌性ＯＰＰフィルムに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxially oriented polypropylene (OPP) film containing silver-containing crystalline zirconium phosphate as an antibacterial agent, which efficiently enhances a high antibacterial effect without impairing the basic performance of the film. It relates to the antibacterial OPP film obtainable.

【０００２】[0002]

【従来の技術】従来より、ポリエチレン、ポリプロピレ
ン等の高分子材料に無機系の抗菌性物質を配合し、それ
をフィルム状に成形することによって、細菌の増殖を防
止する抗菌性フィルムを得る技術がよく知られている。
無機系の抗菌剤としては銀等の抗菌性を有する金属を担
持させた活性炭、ゼオライト等があり、これらは有機系
の抗菌剤と比較して抗菌効果が長期間持続し、耐熱性に
優れ、また安全性が高いために、各種高分子材料に配合
され、これを用いてフィルム等に成形され包装材料等、
各種衛生性を必要とする用途に用いられている。2. Description of the Related Art Conventionally, a technique has been known in which an inorganic antibacterial substance is blended with a polymer material such as polyethylene or polypropylene and then formed into a film to obtain an antibacterial film which prevents bacterial growth. well known.
As an inorganic antibacterial agent, there are activated carbon, zeolite, etc. carrying a metal having antibacterial properties such as silver, and these have a long-lasting antibacterial effect as compared with organic antibacterial agents, and have excellent heat resistance, In addition, because of its high safety, it is blended with various polymer materials and formed into a film etc. using this, and packaging materials etc.
It is used for applications requiring various sanitary properties.

【０００３】[0003]

【発明が解決しようとする課題】無機系の抗菌剤を樹脂
に配合してフィルム成形する場合、粒子状の抗菌剤がフ
ィルムの表面に露出していないと抗菌効果が得られな
い。しかし、単に無機系抗菌剤を公知の方法で樹脂に配
合して成型したのでは、樹脂を押し出す工程で、抗菌剤
が樹脂中に埋没してしまうため、フィルム表面に抗菌剤
を効果的に露出させることは困難である。When a film is formed by blending an inorganic antibacterial agent with a resin, an antibacterial effect cannot be obtained unless the particulate antibacterial agent is exposed on the surface of the film. However, simply blending an inorganic antimicrobial agent into a resin by a known method and molding it would cause the antimicrobial agent to be buried in the resin during the process of extruding the resin, thus effectively exposing the antimicrobial agent to the film surface. It is difficult to do that.

【０００４】抗菌剤が表面に露出し易くするために、抗
菌剤の配合量を多くしたり、また、抗菌剤の粒径を大き
くしたりすることは考えられるが、このような手段で
は、抗菌剤が多量に必要となるため不経済であるばかり
でなく、成型されたフィルムの基本的性能、即ち強度や
加工適性、透明性等を著しく損なってしまう。そのた
め、少ない抗菌剤を効率よくフィルム表面に露出した効
果的に抗菌効果を得られる抗菌性フィルム、特に単独ま
たは紙等に積層することによって包装材料、本等の表紙
など幅広い用途が考えられる抗菌性ＯＰＰフィルムが必
要とされていた。It is conceivable to increase the amount of the antibacterial agent or to increase the particle size of the antibacterial agent in order to make the antibacterial agent more easily exposed to the surface. Not only is it uneconomical since a large amount of the agent is required, but also the basic properties of the formed film, that is, the strength, processability, transparency, etc. are significantly impaired. Therefore, antimicrobial films that can effectively obtain an antimicrobial effect by effectively exposing a small amount of antimicrobial agent to the film surface, especially antibacterial properties that can be used in a wide variety of applications, such as packaging materials and book covers, when used alone or laminated on paper etc. An OPP film was needed.

【０００５】[0005]

【課題を解決するための手段】本発明者らは、上記課題
を解決するために鋭意検討した結果、本発明を以下のよ
うに完成させた。即ち、本発明は、ポリプロピレンフィ
ルム基材層の少なくとも片面に無機系抗菌剤を含有する
抗菌層が積層されている複合ポリプロピレンフィルムに
おいて、前記抗菌層がプロピレンの単独重合体、又はエ
チレンの比率が２.５％以下であるプロピレン・エチレ
ン共重合体に銀含有結晶質リン酸ジルコニウムを配合し
たものからなることを特徴とする抗菌性ＯＰＰフィルム
である。Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, completed the present invention as follows. That is, the present invention provides a composite polypropylene film in which an antibacterial layer containing an inorganic antibacterial agent is laminated on at least one surface of a polypropylene film base layer, wherein the antibacterial layer has a propylene homopolymer or ethylene ratio of 2 An antibacterial OPP film comprising a propylene / ethylene copolymer having a content of 0.5% or less and silver-containing crystalline zirconium phosphate.

【０００６】さらに本発明は、抗菌層に含まれる銀含有
結晶質リン酸ジルコニウムの平均粒子径が０.５〜１.３
μｍであり、抗菌層の膜厚が０.５〜２.０μｍであるこ
とを特徴とする抗菌性ＯＰＰフィルムである。本発明の
抗菌性ＯＰＰフィルムは、基材層を構成するポリプロピ
レンフィルムに、抗菌剤である銀含有結晶質リン酸ジル
コニウムを、プロピレンの単独重合体、もしくはエチレ
ンの比率が２.５％以下のプロピレン・エチレン共重合
体であるポリプロピレンに０.２〜２.５％、好ましくは
０.５〜１.５％配合したものを積層し、公知の方法で二
軸延伸することによって得ることが出来る。Further, according to the present invention, the silver-containing crystalline zirconium phosphate contained in the antibacterial layer has an average particle size of 0.5 to 1.3.
μm, and the thickness of the antibacterial layer is 0.5 to 2.0 μm. The antibacterial OPP film of the present invention is obtained by adding a silver-containing crystalline zirconium phosphate as an antibacterial agent to a polypropylene film constituting a base material layer, a propylene homopolymer or a propylene having an ethylene ratio of 2.5% or less. It can be obtained by laminating a blend of 0.2 to 2.5%, preferably 0.5 to 1.5% with polypropylene which is an ethylene copolymer, and biaxially stretching the laminate by a known method.

【０００７】抗菌層を構成するポリプロピレン樹脂とし
て単独重合体、もしくはエチレンの比率が２.５％以下
の共重合体を使用するのは、共重合体におけるエチレン
の比率が増えるほど、抗菌剤として使用する銀含有結晶
質リン酸ジルコニウムの粒子表面のポリプロピレン樹脂
に対する濡れ性が良くなるため、フィルムに製膜した場
合に、抗菌剤がフィルム表面に露出しにくくなり、その
ため同じ量の抗菌剤を配合しても、フィルムの抗菌性が
得られなくなってしまうためである。A homopolymer or a copolymer having an ethylene ratio of 2.5% or less is used as the polypropylene resin constituting the antibacterial layer. The more the ratio of ethylene in the copolymer increases, the more the polymer is used as an antibacterial agent. Since the wettability of the silver-containing crystalline zirconium phosphate particles on the polypropylene resin is improved, the antibacterial agent is less likely to be exposed on the film surface when formed into a film. However, this is because the antibacterial property of the film cannot be obtained.

【０００８】このとき、抗菌剤の平均粒径は０.５〜１.
３μｍの範囲が好ましい。０.５μｍ以下であると、フ
ィルムの表面に抗菌剤を露出させることが困難になる。
また１.３μｍを越えると、透明度等のフィルムの表面
性が低下する。また、抗菌層の膜厚は０.５〜２.０μｍ
であることが好ましい。０.５μｍを下回ると，延伸時
に積層膜が破れる可能性があり、抗菌性のバラツキの一
因となる。また、膜厚が２.０μを越えると、通常使用
する粒径の抗菌剤のフィルム表面への露出が困難とな
り、抗菌効果が低下する。フィルムの延伸は、通常の二
軸延伸と同様の方法で必要に応じて適宜の倍率で行う。At this time, the average particle size of the antibacterial agent is 0.5 to 1.5.
A range of 3 μm is preferred. When the thickness is less than 0.5 μm, it becomes difficult to expose the antibacterial agent on the surface of the film.
On the other hand, if it exceeds 1.3 μm, the surface properties of the film, such as transparency, decrease. The thickness of the antibacterial layer is 0.5 to 2.0 μm.
It is preferred that When the thickness is less than 0.5 μm, the laminated film may be broken at the time of stretching, which contributes to variation in antibacterial properties. On the other hand, when the thickness exceeds 2.0 μm, it becomes difficult to expose the normally used particle size antibacterial agent to the film surface, and the antibacterial effect is reduced. The stretching of the film is carried out in the same manner as in ordinary biaxial stretching at an appropriate magnification as required.

【０００９】[0009]

【実施例】本発明を以下の実施例、及び比較例によりさ
らに詳細に説明する。但し本発明の内容は実施例に限ら
れるものではない。The present invention will be described in more detail with reference to the following examples and comparative examples. However, the contents of the present invention are not limited to the embodiments.

【００１０】（実施例１〜３）基材層として、通常のＯ
ＰＰ用樹脂（ＭＦＩ ２.５ｇ／minのプロピレン単独重
合体）に、プロピレン単独重合体よりなるポリプロピレ
ン樹脂に銀含有結晶質リン酸ジルコニウム抗菌剤を各々
１.５％、１.０％、０.５％配合した樹脂を積層し、一
般的な二軸延伸フィルムを製膜する方法で、縦延伸倍率
４.５倍、横延伸倍率１０倍で全体厚さ２０μ、抗菌層
膜厚１.５μのフィルムを製膜したものを実施例１〜３
とした。(Examples 1 to 3) As a substrate layer, ordinary O
PP resin (MFI 2.5 g / min propylene homopolymer), polypropylene resin composed of propylene homopolymer, silver-containing crystalline zirconium phosphate antibacterial agent 1.5%, 1.0%, 0.1%, respectively. A method of forming a general biaxially stretched film by laminating a resin blended with 5% of the total thickness of 20 μm and a thickness of antibacterial layer of 1.5 μm at a longitudinal stretch ratio of 4.5 times and a transverse stretch ratio of 10 times. Examples 1 to 3 were obtained by forming films.
And

【００１１】（実施例４〜６）実施例１〜３と同様の基
材層に、エチレンの比率が２.５％であるポリプロピレ
ン樹脂に銀含有結晶質リン酸ジルコニウム抗菌剤を各々
１.５％、１.０％、０.５％配合した樹脂を積層し、実
施例１〜３と同様にフィルムを製膜したものを実施例４
〜６とした。(Examples 4 to 6) In the same base material layer as in Examples 1 to 3, a silver-containing crystalline zirconium phosphate antibacterial agent was added to a polypropylene resin having an ethylene ratio of 2.5% in amounts of 1.5% each. %, 1.0% and 0.5% were laminated, and a film was formed in the same manner as in Examples 1-3.
To 6.

【００１２】（比較例１〜３）抗菌層としてエチレンの
比率が４.５％であるポリプロピレン樹脂に、銀含有結
晶質リン酸ジルコニウム抗菌剤を各々１.５％、１.０
％、０.５％配合した樹脂を使用する以外は実施例と同
様にして比較例１〜３とした。(Comparative Examples 1 to 3) A silver-containing crystalline zirconium phosphate antibacterial agent was added to a polypropylene resin having an ethylene ratio of 4.5% as an antibacterial layer at 1.5% and 1.0% respectively.
%, And Comparative Examples 1 to 3 in the same manner as in Example except that a resin containing 0.5% and 0.5% was used.

【００１３】（比較例４）抗菌剤を配合せず実施例と同
様にフィルムを成膜し、比較例４とした実施例１〜６、
比較例１〜４の結果を表１に示す。(Comparative Example 4) A film was formed in the same manner as in Example without blending an antibacterial agent.
Table 1 shows the results of Comparative Examples 1 to 4.

【００１４】[0014]

【表１】 [Table 1]

【００１５】（実施例７〜１０）抗菌層にはエチレン比
率２.５％のポリプロピレン樹脂（ＭＦＩ ９.０ｇ／１
０分）を用い、フィルムの全体厚さは２０μｍのまま、
抗菌層の膜厚を各々０.５μｍ、１.０μｍ．１.５μ
ｍ、２.０μｍと変えた他は実施例と同様にフィルムを
成膜したものを実施例７〜１０とした。(Examples 7 to 10) A polypropylene resin having an ethylene ratio of 2.5% (MFI 9.0 g / 1) was used for the antibacterial layer.
0 minutes) and the overall thickness of the film remains at 20 μm,
The thicknesses of the antimicrobial layers were 0.5 μm and 1.0 μm, respectively. 1.5μ
Examples 7 to 10 were films formed in the same manner as in the example except that m was changed to 2.0 μm.

【００１６】（比較例５）抗菌層の膜厚を３.０μｍと
した他は、実施例７〜１０と同様にフィルムを製膜した
ものを比較例５とした。Comparative Example 5 A film was formed in the same manner as in Examples 7 to 10 except that the film thickness of the antibacterial layer was 3.0 μm.

【００１７】（比較例６）抗菌層の膜厚を０.２μｍと
した他は、実施例７〜１０と同様にフィルムを製膜した
ものを比較例６とした。このようにして得られたフィル
ムは、抗菌層が破れ表面の外観が斑状となっていた。実
施例７〜１０、比較例５〜６の結果を表２に示す。Comparative Example 6 A film was formed in the same manner as in Examples 7 to 10 except that the film thickness of the antibacterial layer was 0.2 μm. In the film thus obtained, the antibacterial layer was broken, and the surface appearance was patchy. Table 2 shows the results of Examples 7 to 10 and Comparative Examples 5 to 6.

【００１８】[0018]

【表２】 [Table 2]

【００１９】なお、実施例及び比較例で使用した抗菌剤
はノバロンＭＺ７１００（東亜合成製）である。抗菌剤
の平均粒径は１.３μｍである。また、抗菌剤の配合率
は重量％で示す。又、抗菌性の評価方法は以下の通りで
ある。 ＜抗菌性評価方法＞得られたＯＰＰフィルムを細かく裁
断して試料とし、試料０.５ｇをリン酸緩衝液５mlに入
れて大腸菌の懸濁液を５ml加え、２７℃で２４時間振と
う後、生菌数を測定した。The antibacterial agent used in Examples and Comparative Examples is Novalon MZ7100 (manufactured by Toagosei Co., Ltd.). The average particle size of the antimicrobial is 1.3 μm. The compounding ratio of the antibacterial agent is shown by weight%. The method for evaluating antibacterial properties is as follows. <Antibacterial evaluation method> The obtained OPP film was finely cut into a sample, and 0.5 g of the sample was placed in 5 ml of a phosphate buffer, 5 ml of a suspension of Escherichia coli was added, and the mixture was shaken at 27 ° C for 24 hours. The number of viable bacteria was measured.

【００２０】[0020]

【発明の効果】本発明により得られた抗菌性ＯＰＰフィ
ルムは、フィルムの基本的性能を損なわず、高い抗菌効
果を効率良く得ることのできる抗菌性ＯＰＰフィルムを
得ることができる。According to the antibacterial OPP film obtained by the present invention, an antibacterial OPP film capable of efficiently obtaining a high antibacterial effect without impairing the basic performance of the film can be obtained.

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 ポリプロピレンフィルム基材層の少なく
とも片面に無機系抗菌剤を含有する抗菌層が積層されて
いる複合ポリプロピレンフィルムにおいて、前記抗菌層
がプロピレンの単独重合体、又はエチレンの比率が２.
５％以下であるプロピレン・エチレン共重合体に銀含有
結晶質リン酸ジルコニウムを配合したものからなること
を特徴とする抗菌性二軸延伸ポリプロピレンフィルム。1. A composite polypropylene film in which an antibacterial layer containing an inorganic antibacterial agent is laminated on at least one surface of a polypropylene film base layer, wherein the antibacterial layer has a propylene homopolymer or ethylene ratio of 2.
An antibacterial biaxially stretched polypropylene film comprising a propylene / ethylene copolymer containing 5% or less and silver-containing crystalline zirconium phosphate. 【請求項２】 銀含有結晶質リン酸ジルコニウムの平均
粒子径が０.５〜１.３μｍであり、抗菌層の膜厚が０.
５〜２.０μｍであることを特徴とする請求項１記載の
抗菌性二軸延伸ポリプロピレンフィルム。2. The silver-containing crystalline zirconium phosphate has an average particle size of 0.5 to 1.3 μm and a thickness of the antibacterial layer of 0.5.
The antibacterial biaxially stretched polypropylene film according to claim 1, wherein the thickness is 5 to 2.0 µm.