JPH0796627B2 - Polyolefin microporous membrane - Google Patents
Polyolefin microporous membraneInfo
- Publication number
- JPH0796627B2 JPH0796627B2 JP62297248A JP29724887A JPH0796627B2 JP H0796627 B2 JPH0796627 B2 JP H0796627B2 JP 62297248 A JP62297248 A JP 62297248A JP 29724887 A JP29724887 A JP 29724887A JP H0796627 B2 JPH0796627 B2 JP H0796627B2
- Authority
- JP
- Japan
- Prior art keywords
- microporous membrane
- polyolefin
- antioxidant
- film
- present
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、電池、電解コンデンサ、電気２重層コンデン
サ等のセパレータ、あるいはミクロフィルターとして用
いられるポリオレフィン微孔性フィルムに関するもので
ある。TECHNICAL FIELD The present invention relates to a polyolefin microporous film used as a separator for batteries, electrolytic capacitors, electric double layer capacitors, or the like, or as a microfilter.
［従来の技術］ 電池、電解コンデンサ、電気２重層コンデンサ等では、
空孔の均一性に優れ、機械強度にも優れるポリオレフィ
ン微孔膜の使用が進められている（例えば特開昭51-188
51号、特開昭61-13614号、実開昭59-140429号等）。[Prior Art] For batteries, electrolytic capacitors, electric double layer capacitors, etc.,
The use of polyolefin microporous membranes, which have excellent pore uniformity and mechanical strength, is being promoted (for example, JP-A-51-188).
51, JP-A-61-13614, JP-A-59-140429, etc.).
［発明が解決しようとする問題点］ しかしながら、こうした微孔膜の使用において問題視さ
れていることとして、素子内に含まれる酸素、あるいは
過酸化物・ラジカルの発生のために、長時間での高温使
用により、該ポリオレフィン樹脂がしばしば酸化劣化を
生じ、低分子量化し機械的に脆くショート等を生じるこ
とがある。[Problems to be Solved by the Invention] However, it is regarded as a problem in the use of such a microporous film that oxygen and / or peroxide / radicals contained in the device are generated, so that a long time is required. When used at high temperatures, the polyolefin resin often undergoes oxidative deterioration, has a low molecular weight, and is mechanically fragile and may cause a short circuit or the like.
本発明は該状況を鑑み、素子中での酸化劣化等による機
械強度の低下を防止し長期信頼性を付与せんとするもの
である。In view of the above situation, the present invention is intended to prevent deterioration of mechanical strength due to oxidative deterioration in an element and to provide long-term reliability.
［問題点を解決するための手段］ 本発明は、表面空孔径0.01〜５μｍ、空孔率30〜90％で
あるポリオレフィン微孔膜において、該微孔膜10gあた
り0.001〜0.5gのポリオレフィン用酸化防止剤を塗布し
てなるポリオレフィン微孔膜に関するものである。[Means for Solving Problems] The present invention relates to a polyolefin microporous membrane having a surface pore diameter of 0.01 to 5 μm and a porosity of 30 to 90%, and 0.001 to 0.5 g of oxidation for polyolefin per 10 g of the microporous membrane. The present invention relates to a polyolefin microporous membrane coated with an inhibitor.
本発明において、ポリオレフィンとはポリエチレン、ポ
リプロピレン、ポリ４メチルペンテン１、ポリブテン等
のαオレフィンのホモポリマー、コポリマー、あるいは
これらのブレンド物であり、この中でも耐溶剤性・機械
特性に優れる高密度ポリエチレン、ポリプロピレンが好
ましい。In the present invention, the polyolefin is a homopolymer or copolymer of α-olefin such as polyethylene, polypropylene, poly-4-methylpentene 1, polybutene, or a blend thereof, among which high-density polyethylene having excellent solvent resistance and mechanical properties, Polypropylene is preferred.
特に、ポリプロピレンである場合、機械特性、耐溶剤性
の点で極限粘度（［η］）が1.8〜3.3dl/gのものが好ま
しく、より好ましくは2.1〜3.3dl/g、さらに好ましくは
2.7〜3.2dl/gである。アイソタクチックインデックス
（II）も同様の理由で93％以上が好ましく、より好まし
くは96％以上である。Particularly, in the case of polypropylene, it is preferable that the intrinsic viscosity ([η]) is 1.8 to 3.3 dl / g, more preferably 2.1 to 3.3 dl / g, and further preferably, from the viewpoint of mechanical properties and solvent resistance.
It is 2.7 to 3.2 dl / g. The isotactic index (II) is also preferably 93% or more, and more preferably 96% or more for the same reason.
次の本発明において、表面空孔径は0.01〜５μｍである
ことが必要であり、好ましくは0.6〜４μｍである。空
孔径が0.01μｍ未満であると、電解液の含浸性に劣り問
題を生じる。一方空孔径が５μｍを越えると導電粒子等
の通過を遮断できずショート率が増大する。In the following invention, the surface pore diameter needs to be 0.01 to 5 μm, preferably 0.6 to 4 μm. If the pore diameter is less than 0.01 μm, impregnation with the electrolytic solution is poor and a problem occurs. On the other hand, if the pore diameter exceeds 5 μm, the passage of conductive particles cannot be blocked and the short-circuit rate increases.
また本発明微孔膜の空孔率は30〜90％であることが必要
であり、好ましくは50〜70％である。空孔率が30％より
も小さいと電解液保持量が低下し、ドライアップ等の問
題を生じる。一方空孔率が90％よりも大きいと機械強度
が不足し、ショート等の問題を生じる。Further, the porosity of the microporous membrane of the present invention is required to be 30 to 90%, preferably 50 to 70%. If the porosity is less than 30%, the amount of electrolyte retained decreases, causing problems such as dry-up. On the other hand, if the porosity is higher than 90%, the mechanical strength becomes insufficient, causing a problem such as a short circuit.
さらに該微孔膜には10gあたり0.001〜0.5gのポリオレフ
ィン用酸化防止剤が塗布されていることが必要であり、
好ましくは、0.05〜0.2gである。該酸化防止剤の塗布量
が0.001g未満である場合、長期高温使用時の劣化が著し
く問題を生じる。一方塗布量が0.5gを越えるという電気
特性上に問題を生じる。Further, the microporous membrane needs to be coated with 0.001 to 0.5 g of polyolefin antioxidant per 10 g,
It is preferably 0.05 to 0.2 g. When the coating amount of the antioxidant is less than 0.001 g, deterioration during use at high temperature for a long time causes a serious problem. On the other hand, a coating amount of more than 0.5 g causes a problem in electrical characteristics.
本発明でいう酸化防止剤とは、「酸化防止剤ハンドブッ
ク」（大成社刊）、「高分子添加剤・改質剤の評価と市
場」（CMC社刊）等に記載のポリオレフィン用酸化防止
剤を指し、2,6−ジ−ｔ−ブチル−ｐクレゾール［BH
T］、2,6−ジ−ｔ−ブチル−ｐフェノール、テトラキシ
［メチレン−３−（3,5−ジ−ｔ−ブチル−４−ヒドロ
キシフェノール）−プロピオネート］メタン［Irganox
1010］等に例示されるフェノール系酸化防止剤、N,N′
−ジフェニル−ｐ−フェニレンジアミンに例示されるア
ミン系酸化防止剤、ジラウリルチオジプロピオネートに
例示される有機硫黄系酸化防止剤、トリフェニルフォス
ファイトに例示されるフォスファイト系酸化防止剤等が
挙げられるが、これらの中でも、フェノール系酸化防止
剤から選ばれたいずれかのものあるいはこれらの組み合
わせであると低分子量化阻止効果が大きく好ましい。The antioxidant in the present invention means an antioxidant for polyolefin as described in "Antioxidant Handbook" (Taisei Publishing Co., Ltd.), "Evaluation and Market of Polymer Additives / Modifiers" (CMC Publishing), etc. 2,6-di-t-butyl-p-cresol [BH
T], 2,6-di-t-butyl-pphenol, tetraxy [methylene-3- (3,5-di-t-butyl-4-hydroxyphenol) -propionate] methane [Irganox
1010] and the like, phenolic antioxidants, N, N ′
-Amine-based antioxidants such as diphenyl-p-phenylenediamine, organic sulfur-based antioxidants such as dilaurylthiodipropionate, and phosphite-based antioxidants such as triphenyl phosphite Among them, any one selected from the phenolic antioxidants or a combination thereof is preferable because of its large effect of inhibiting lowering of the molecular weight.
さらに本発明でいう塗布とは、例えば少なくとも表裏連
続貫通している微細孔を有する微孔性膜を上述の酸化防
止剤を所定量溶解した溶媒を含浸し、該溶媒を乾燥除去
して成るものであり、この結果該微孔膜に形成された微
細孔表面にも薄く塗布されている状態が好ましい。Further, the coating in the present invention is, for example, a method in which a microporous film having at least fine holes continuously penetrating the front and back is impregnated with a solvent in which a predetermined amount of the above-mentioned antioxidant is dissolved and the solvent is dried and removed. As a result, it is preferable that the surface of the micropores formed in the microporous membrane is thinly applied.
本発明においては、この「塗布」という要件が必須であ
り、かつ、重要な要件となる。たとえば、酸化防止剤を
樹脂に含有させた状態では、ポリオレフィン微孔膜の有
効な酸化劣化防止効果が得られず、「塗布」することに
よって初めて、所望の効果が得られるようになる。In the present invention, this requirement of "coating" is essential and an important requirement. For example, when an antioxidant is contained in the resin, the effective effect of preventing the oxidative deterioration of the polyolefin microporous membrane cannot be obtained, and the desired effect can be obtained only by "coating".
本発明において、熱収縮率は６％以下であることが好ま
しく、さらに好ましくは、４％以下としておくと、素子
を形成した際の経時変化が小さくなり好ましい。In the present invention, the heat shrinkage ratio is preferably 6% or less, and more preferably 4% or less, which is preferable because the change with time when the element is formed is small.
本発明フィルムの厚みは、特にセパレータとして使用す
る際には、50μｍ未満、特に10〜45μｍの範囲のもの
が、電気特性、機械特性共に良好になるので好ましい。The thickness of the film of the present invention, particularly when used as a separator, is preferably less than 50 μm, and particularly preferably in the range of 10 to 45 μm, since both electric properties and mechanical properties are improved.
さらに、本発明微孔性フィルムには電解液との親和性を
良好とする上で、親水化処理を施しておくことが好まし
く、処理方法としては、界面活性剤、コロナ・プラズマ
等の放電処理、グラフト処理、紫外線処理あるいはこれ
らの組み合わせが挙げられる。これらの中でも、界面活
性剤処理が得られる品質及びコスト性に優れよく使用さ
れ、特に該酸化防止剤を所定量界面活性処理液にブレン
ドしておくと良い。Further, the microporous film of the present invention is preferably subjected to a hydrophilization treatment in order to improve the affinity with an electrolytic solution, and the treatment method includes a discharge treatment using a surfactant, corona plasma, or the like. , Graft treatment, ultraviolet treatment, or a combination thereof. Among these, the surfactant treatment is often used because of its excellent quality and cost performance, and it is particularly preferable to blend a predetermined amount of the antioxidant with the surfactant treatment liquid.
また、本発明フィルムには、必要に応じ酸化防止剤だけ
でなく、熱安定剤、滑り剤等を目的に反しない範囲で添
加しても良い。また、製造工程上必然的に、あるいは、
親水化処理を目的として、シリカ、炭酸カルシウム等の
無機微粒子を添加しても良いが、しばしば、こうした無
機微粒子は電解液中での長期使用中に溶解し、電気特性
に悪影響を与えることがあり、添加する場合でも必要最
少限にとどめるか、極力添加しないことが好ましい。Further, not only an antioxidant but also a heat stabilizer, a slipping agent and the like may be added to the film of the present invention as long as it does not contradict the purpose. Also, inevitably in the manufacturing process, or
Inorganic fine particles such as silica and calcium carbonate may be added for the purpose of hydrophilic treatment, but such inorganic fine particles often dissolve during long-term use in an electrolytic solution and may adversely affect the electrical characteristics. Even when added, it is preferable to keep the amount to the minimum necessary or not add it as much as possible.
次に、本発明微孔性フィルムの製造法について述べる
が、もちろんこれに限定されるものではない。Next, a method for producing the microporous film of the present invention will be described, but of course the invention is not limited thereto.
ポリオレフィン粉末と後述する常温有機固体とを溶融ブ
レンドしＴダイ、円形ダイ等よりシートあるいはチュー
ブ状に成形し冷却固化する。The polyolefin powder is melt-blended with an organic solid at room temperature, which will be described later, and molded into a sheet or tube with a T die, a circular die or the like, and then cooled and solidified.
ここで述べる有機固体とは、ポリオレフィンとのブレン
ド性、抽出性の点で、融点が35〜100℃、分子量200〜10
00であることが好ましく、さらに該有機固体の分子構造
中には分極性及び極性基を含有していることが好まし
い。ここで、分極性の基とは芳香族環を指し、極性基と
は、理科学辞典（岩波書店）に示されているような有極
性分子を含む基であって、例えばカルボニル基、アミノ
基、水酸基等を指す。以上のような特性を有する有機固
体の中でも、塩化ビニル等の可塑剤として使用されてい
るフタル酸エステル、リン酸エステル等が優れており、
特にジシクロヘキシルフタレート（DCHP）、トリフェニ
ルフォスフェイト（TPP）から選ばれた少なくとも１種
であることが好ましい。The organic solid described here has a melting point of 35 to 100 ° C. and a molecular weight of 200 to 10 in terms of blendability with polyolefin and extractability.
It is preferably 00, and it is preferable that the molecular structure of the organic solid contains polarizable and polar groups. Here, the polarizable group refers to an aromatic ring, and the polar group is a group containing a polar molecule as shown in the RIKEN Science Dictionary (Iwanami Shoten), such as a carbonyl group or an amino group. , Hydroxyl group, etc. Among the organic solids having the above characteristics, phthalic acid esters, phosphoric acid esters and the like used as plasticizers such as vinyl chloride are excellent,
Particularly, at least one selected from dicyclohexyl phthalate (DCHP) and triphenyl phosphate (TPP) is preferable.
該有機固体の添加量は、ポリオレフィン樹脂100重量部
に対し、80〜250重量部、好ましくは90〜200重量部であ
ると製膜性が良好となり、均一性、連続性に優れた微細
孔が形成されるので好ましい。The addition amount of the organic solid is 80 to 250 parts by weight, preferably 90 to 200 parts by weight, with respect to 100 parts by weight of the polyolefin resin, the film forming property becomes good, and the fine pores having excellent uniformity and continuity are formed. It is preferable because it is formed.
以上のようにして得られた有機固体を含有するポリオレ
フィンシートを該有機固体の添加量の少なくとも95％以
上を抽出することにより得られる。The polyolefin sheet containing the organic solid obtained as described above is obtained by extracting at least 95% or more of the added amount of the organic solid.
ここで、さらに少なくとも一軸に10倍未満延伸すると微
孔膜の均一性に優れているので好ましく、トータル延伸
倍率２〜15倍であると好ましい。さらに、該延伸温度
は、未延伸シートの走査型熱量計（DSC）で観測される
該ポリオレフィンに起因する融点［複数ピークが観測さ
れる場合、それらの平均値］（Tm）−60℃〜Tm-10℃の
範囲であると好ましい。Here, further stretching at least uniaxially less than 10 times is preferable because the uniformity of the microporous membrane is excellent, and a total stretching ratio of 2 to 15 times is preferable. Further, the stretching temperature is a melting point observed by a scanning calorimeter (DSC) of an unstretched sheet due to the polyolefin [when a plurality of peaks are observed, their average value] (Tm) -60 ° C to Tm. It is preferably in the range of -10 ° C.
また、抽出工程と延伸工程とは、適宜組み合わせて良
く、上述した延伸→抽出、抽出→延伸以外に、部分抽出
を行ない延伸後完全に抽出しても良い。Further, the extraction step and the stretching step may be appropriately combined, and in addition to the above-mentioned stretching-extraction and extraction-stretching, partial extraction may be carried out to completely extract after stretching.
以上のようにして得られた微孔性フィルムは、酸化防止
剤を溶解した溶媒槽中に含浸の後、オーブン中で乾燥
し、本発明フィルムを得る。The microporous film obtained as described above is impregnated in a solvent bath in which an antioxidant is dissolved and then dried in an oven to obtain the film of the present invention.
また、上述のように有機固体を抽出する製法の場合、抽
出溶媒にあらかじめ添加しておく方法が可能であり、更
に延伸する場合には、延伸工程の前工程で、もしくは延
伸中に塗布することができる。Further, in the case of the production method of extracting the organic solid as described above, a method of adding it to the extraction solvent in advance is possible, and in the case of further stretching, it may be applied before the stretching step or during the stretching. You can
［発明の効果］ 本発明では、表面空孔径0.01〜５μｍ、空孔率30〜90％
であるポリオレフィン微孔膜といった通常のポリオレフ
ィンフィルムと異なり、極めて表面積が大きいために、
酸素・ラジカル等との反応が促進され易いフィルムにお
いて、表層に該微孔膜10gあたり0.001〜0.5gのポリオレ
フィン用酸化防止剤を塗布することにより、長期高温使
用においても酸化劣化による低分子量化を抑え機械強度
の低下を極力抑えるものであり、特に長期信頼性の要求
される電池、電解コンデンサ、電気２重層コンデンサ等
のセパレータとして極めて優れた特性を発揮できる。[Effect of the Invention] In the present invention, the surface pore diameter is 0.01 to 5 μm, and the porosity is 30 to 90%.
Unlike ordinary polyolefin films such as polyolefin microporous membrane, which has an extremely large surface area,
In the film where the reaction with oxygen and radicals is easily promoted, by coating the surface layer with the antioxidant for polyolefin of 0.001 to 0.5 g per 10 g of the microporous film, the molecular weight reduction due to oxidative deterioration can be achieved even in long-term high temperature use. It suppresses a decrease in mechanical strength as much as possible, and can exhibit extremely excellent characteristics as a separator for batteries, electrolytic capacitors, electric double layer capacitors, etc., which require long-term reliability.
［特性の評価方法及び効果の評価方法］ 次にこの発明に関する特性の測定方法及び効果の評価方
法をまとめて示す。[Characteristic Evaluation Method and Effect Evaluation Method] Next, the characteristic measurement method and effect evaluation method relating to the present invention will be summarized.
（１） 極限粘度（［η］） ASTM-D-1601に準じ、使用0.1gを135℃のテトラリン100m
lに完全溶解させ、この溶液を粘度計で135℃の恒温槽中
で測定して、比粘度Ｓより次式に従って求める。(1) Intrinsic viscosity ([η]) According to ASTM-D-1601, use 0.1g of tetralin 100m at 135 ℃.
It is completely dissolved in 1 and this solution is measured with a viscometer in a constant temperature bath at 135 ° C. and determined from the specific viscosity S according to the following formula.
［η］＝S/｛0.1×（１＋0.22×Ｓ）｝ （２） アイソタクチックインデックス（II） 試料を130℃で２時間真空乾燥する。これから重量Ｗ（m
g）の試料を取り、ソックスレー抽出器に入れ、沸騰ｎ
−ヘプタンで12時間抽出する。[Η] = S / {0.1 × (1 + 0.22 × S)} (2) Isotactic Index (II) The sample is vacuum dried at 130 ° C. for 2 hours. From now on, weight W (m
Take the sample of g), put it in a Soxhlet extractor, and boil it n
-Extract for 12 hours with heptane.
次に、この試料を取出し、アセトンで十分洗浄した後、
130℃６時間真空乾燥し、その後重量Ｗ′（mg）を測定
し、次式で求める。Next, after taking out this sample and thoroughly washing with acetone,
After vacuum drying at 130 ° C. for 6 hours, the weight W ′ (mg) is measured and determined by the following formula.
II（％）＝（Ｗ′/W）×100 （３） 表面空孔径（ａ） サンプル表面の走査型電子顕微鏡（SEM）観察により孔
径の長軸（ax）及び短軸（ay）を測定し、次式に示す相
乗平均を表面空孔径とする。II (%) = (W '/ W) x 100 (3) Surface pore diameter (a) The long axis (a x ) and short axis (a y ) of the pore diameter can be determined by observing the sample surface with a scanning electron microscope (SEM). It is measured, and the geometric mean shown in the following formula is defined as the surface pore diameter.
（４） 空孔率（Ｐ） 試料（10×10cm）流動パラフィンに24時間浸漬し、表層
の流動パラフィンを十分に拭き取った後の重量（W2）を
測定し、該試料の浸漬前の重量（W1）及び流動パラフィ
ンの密度（ρ）より次式で求める。 (4) Porosity (P) The sample (10 × 10 cm) was immersed in liquid paraffin for 24 hours, and the weight (W 2 ) after the surface liquid paraffin was sufficiently wiped off was measured. (W 1 ) and the density (ρ) of liquid paraffin are calculated by the following formula.
Ｐ＝（W2-W1）／（Ｖ×ρ） ここで、Ｖは試料の見かけ体積（厚み、寸法より計算さ
れる値）である。P = (W 2 −W 1 ) / (V × ρ) Here, V is the apparent volume (value calculated from thickness and size) of the sample.
（５） 劣化テスト方法 試料（10×10cm）をプロピレンカーボネート浴中（200c
c）に浸漬し、空気雰囲気中で（85℃10時間＋室温放令1
4時間）のサイクルを３回繰り返した後、エチルアルコ
ールで十分にプロピレンカーボネートを除去し、空気中
で乾燥する。(5) Degradation test method A sample (10 x 10 cm) was placed in a propylene carbonate bath (200 c
c), and in an air atmosphere (85 ° C for 10 hours + room temperature release 1
After repeating the cycle of 4 hours) three times, the propylene carbonate is sufficiently removed with ethyl alcohol and dried in air.
この時、試料の劣化度は浸漬前後での長手方向の破断強
度を測定し次式で求める。At this time, the degree of deterioration of the sample is determined by the following formula by measuring the breaking strength in the longitudinal direction before and after the immersion.
（劣化度）＝（S1-S2）／S1×100（％） S1：浸漬前の強度 S2：浸漬後の強度 強度はJISK6782に準拠し測定する。(Degradation degree) = (S 1 -S 2 ) / S 1 × 100 (%) S 1 : Strength before immersion S 2 : Strength after immersion Strength is measured according to JIS K6782.
［実施例］ 次にこの発明の実施例及び比較例を示し、この発明の効
果をより具体的に説明する。[Examples] Next, examples and comparative examples of the present invention will be shown to more specifically describe the effects of the present invention.
実施例１及び比較例１ ポリオレフィン樹脂として、ポリプロピレンパウダー
（三井東圧ノーブレンJSタイプ）を容易し、ジシクロヘ
キシルフタレート（DCHP）をPP100重量部に対し150重量
部を溶融ブレンドし、Ｔダイを用いシート状の押出し冷
却固化した。引き続き該シートに含まれるDCHPの98％以
上を１−１−１トリクロルエタンで抽出除去した後にIr
ganox 1010（テトラキシ［メチレン−３−（3,5−ジ−
ｔ−ブチル−４−ヒドロキシフェノール）−プロピオネ
ート］メタン）の１−１−１トリクロルエタン溶液バス
を通し乾燥を行なった。引き続き130℃にて3.5倍長手方
向に延伸しさらに横方向に140℃にて1.4倍延伸し巻き取
った。Example 1 and Comparative Example 1 As a polyolefin resin, polypropylene powder (Mitsui Toatsu Noblen JS type) was prepared, and 150 parts by weight of dicyclohexyl phthalate (DCHP) was melt-blended with 100 parts by weight of PP, and a sheet was formed using a T-die. Was extruded, cooled and solidified. Subsequently, 98% or more of DCHP contained in the sheet was extracted and removed with 1-1-1 trichloroethane, and then Ir was removed.
ganox 1010 (tetraxy [methylene-3- (3,5-di-
t-Butyl-4-hydroxyphenol) -propionate] methane) was dried through a 1-1-1 trichloroethane solution bath. Subsequently, the film was stretched 3.5 times in the longitudinal direction at 130 ° C., further drawn 1.4 times in the transverse direction at 140 ° C. and wound up.
以上の様にして得られた微孔膜にはIrganox 1010がフィ
ルム10gあたり0.05g塗布された。又、膜厚は30μｍであ
った。（実施例１） また、実施例１において、Irganox 1010とBHT（2,6−ジ
−ｔ−ブチル−ｐクレゾール）とを3:1の重量比で１−
１−１トリクロルエタンに溶解し同様に塗布した。この
結果、全酸化防止剤量が0.02g/10g塗布された。（実施
例２） 以上の酸化防止剤を塗布した微孔膜と上述の製造工程に
おいて塗布を行なわなかった微孔膜（比較例１）に関し
劣化テストを行なった結果、塗布を行なった実施例1,2
では、比較例１に比べ機械強度の低下（劣化度）が小さ
く優れている。Irganox 1010 was applied to the microporous membrane obtained as described above in an amount of 0.05 g per 10 g of the film. The film thickness was 30 μm. (Example 1) Further, in Example 1, Irganox 1010 and BHT (2,6-di-t-butyl-p-cresol) were mixed at a weight ratio of 3: 1 of 1-.
It was dissolved in 1-1 trichloroethane and coated in the same manner. As a result, the total amount of antioxidant was 0.02 g / 10 g. (Example 2) As a result of performing a deterioration test on the above-described microporous film coated with an antioxidant and a microporous film not coated in the above manufacturing process (Comparative Example 1), Example 1 was coated. , 2
In comparison, as compared with Comparative Example 1, the decrease in mechanical strength (deterioration degree) is small and it is excellent.
実施例３及び比較例２ ポリオレフィン樹脂として、PPペレット（住友化学
（株）製WF900タイプ）を230℃で溶融押出し、ドラフト
比50にて65℃の水槽中で冷却固化した。こうして得られ
たキャストフィルムを150℃２分間熱処理した結果、特
公昭50-2176に記載の弾性回復率が92％のフィルムが得
られた。次いで、該熱処理フィルムを60℃、延伸速度10
0％／分にて２倍に延伸し、さらに130℃にて1.5倍延伸
の後、Ionox 330（1,3,5−トリメチル−2,4,6−トリ
（3,5−ジ−ｔ−ブチル−４−ヒドロキシ−ベンジル）
ベンゼン）のベンゼン溶液に浸漬しベンゼンを乾燥し最
後に150℃にて５分間熱処理し巻取った。この結果Ionox
が微孔膜重量10gあたり0.07g塗布された。また膜厚は25
μｍであった。（実施例３） これと塗布を行なわなかったもの（比較例２）と比較し
劣化テストを行なった結果、表１のごとくなり塗布の効
果により著しく劣化度が低減されていることが判る。Example 3 and Comparative Example 2 As a polyolefin resin, PP pellets (WF900 type manufactured by Sumitomo Chemical Co., Ltd.) were melt extruded at 230 ° C. and cooled and solidified in a water tank at 65 ° C. with a draft ratio of 50. The cast film thus obtained was heat-treated at 150 ° C. for 2 minutes, and as a result, a film having an elastic recovery rate of 92% described in JP-B-50-2176 was obtained. Then, the heat-treated film is stretched at 60 ° C. at a stretching speed of 10
The film was stretched 2 times at 0% / min and further stretched 1.5 times at 130 ° C., and then Ionox 330 (1,3,5-trimethyl-2,4,6-tri (3,5-di-t- Butyl-4-hydroxy-benzyl)
(Benzene) was dipped in a benzene solution to dry the benzene, and finally heat-treated at 150 ° C. for 5 minutes and wound. This result in Ionox
Was applied at 0.07 g per 10 g of microporous membrane. The film thickness is 25
was μm. (Example 3) As a result of performing a deterioration test by comparing this with the one not applied (Comparative Example 2), it is found that the deterioration is remarkably reduced due to the effect of application as shown in Table 1.
実施例４及び比較例３ ポリオレフィン樹脂として高密度ポリエチレン（“ハイ
ゼックス"3300F）を用い、実施例１と同様にDCHPと溶融
ブレンドし、Ｔダイより50μｍのシートを押出した。該
シートを１−１−１トリクロルエタンで抽出の後、空孔
径0.5μｍ、空孔率54％の微孔膜を得た。こうして得ら
れた微孔膜を実施例３と同様にIonoxのベンゼン溶液に
浸漬し、Ionoxを0.03g/10g塗布したもの（実施例４）と
しないもの（比較例３）とで劣化テストを行なった。こ
の結果表１に示すように実施例４では著しく劣化度が小
さい。Example 4 and Comparative Example 3 High density polyethylene (“HIZEX” 3300F) was used as a polyolefin resin, melt-blended with DCHP in the same manner as in Example 1, and a sheet of 50 μm was extruded from a T-die. After extracting the sheet with 1-1-1 trichloroethane, a microporous membrane having a pore size of 0.5 μm and a porosity of 54% was obtained. The microporous membrane thus obtained was immersed in a benzene solution of Ionox in the same manner as in Example 3, and a deterioration test was carried out with those coated with 0.03 g / 10 g of Ionox (Example 4) and those not coated (Comparative Example 3). It was As a result, as shown in Table 1, the deterioration degree is remarkably small in Example 4.
比較例４ ポリオレフィン樹脂として、ポリプロピレンパウダー
（三井東圧ノーブレンJSタイプ）に酸化防止剤としてIr
ganox1010を0.05重量％添加したものを用意した。この
酸化防止剤含有ポリオレフィン樹脂原料を用いて、比較
例１と同様に微孔膜を製造した。得られた微孔膜の特性
を表１に示す。Comparative Example 4 Polypropylene powder (Mitsui Toatsu Nobren JS type) was used as the polyolefin resin, and Ir was used as the antioxidant.
The thing which added 0.05% of the weight of ganox1010 was prepared. Using this antioxidant-containing polyolefin resin raw material, a microporous membrane was produced in the same manner as in Comparative Example 1. The characteristics of the obtained microporous membrane are shown in Table 1.
表１に示すように、酸化防止剤を、「塗布」によらず、
樹脂中に含有させる方法では、劣化度改善の効果が得ら
れなかった。As shown in Table 1, an antioxidant was used regardless of "application".
The effect of improving the degree of deterioration could not be obtained by the method of incorporating it in the resin.
すなわち、樹脂に酸化防止剤を入れても、1,1,1−トリ
クロルエタンの抽出時に、実質的に酸化防止剤も一緒に
抽出されるので、効果的には比較例１と同様の結果とな
る。That is, even if the antioxidant is added to the resin, the antioxidant is substantially extracted together with the extraction of 1,1,1-trichloroethane, so that the same results as in Comparative Example 1 are obtained. Become.
実施例５及び比較例５ 実施例１で得られた微孔膜と比較例１で得られた微孔膜
に界面活性剤として、“ノニポール95"（三洋化成
（株）製、ポリオキシエチレンノニルフェニルエーテ
ル）を用い親水化処理した後、平均粒径2.5μｍの活性
炭を両極に配し、30重量％の希硫酸を含浸させ、電気２
重層コンデンサのセルを作成した（電子通信学会技術研
究報告CPM81-77等） こうして得られたセルを85℃で500時間エージングし、
解体後用いた微孔膜の機械強度を測定し、劣化度を求め
た結果下表のようになりIrganox 1010を塗布した微孔膜
を使用した実施例５ではほとんど機械強度が低下してお
らず信頼性が高いことが判る。 Example 5 and Comparative Example 5 "Nonipol 95" (manufactured by Sanyo Kasei Co., Ltd., polyoxyethylene nonyl) was used as a surfactant in the microporous membrane obtained in Example 1 and the microporous membrane obtained in Comparative Example 1. (Phenyl ether), then activated carbon with an average particle size of 2.5 μm is placed on both electrodes and impregnated with 30% by weight of dilute sulfuric acid.
A cell of a multilayer capacitor was created (Technical Report of the Institute of Electronics and Communication Engineers CPM81-77 etc.) The cell thus obtained was aged at 85 ° C for 500 hours,
The mechanical strength of the microporous membrane used after dismantling was measured, and the degree of deterioration was determined. The result is as shown in the table below. In Example 5 using the microporous membrane coated with Irganox 1010, the mechanical strength was hardly reduced. It turns out that it is highly reliable.
以上のように本発明微孔膜及びこれを用いたセパレータ
では、長時間高温で電解液等の溶媒に浸漬された場合で
も機械強度の変化が小さいことが判る。 As described above, it is understood that the microporous membrane of the present invention and the separator using the same have a small change in mechanical strength even when immersed in a solvent such as an electrolytic solution at high temperature for a long time.
フロントページの続き (56)参考文献 特開 昭50−34335（ＪＰ，Ａ) 特開 昭61−253361（ＪＰ，Ａ) 特開 昭56−159128（ＪＰ，Ａ)Continuation of the front page (56) Reference JP-A-50-34335 (JP, A) JP-A-61-253361 (JP, A) JP-A-56-159128 (JP, A)
Claims (1)
であるポリオレフィン微孔膜において、該微孔膜10gあ
たり0.001〜0.5gのポリオレフィン用酸化防止剤を塗布
してなるポリオレフィン微孔膜。1. Surface pore diameter 0.01 to 5 μm, porosity 30 to 90%
The polyolefin microporous membrane, wherein 0.001 to 0.5 g of the antioxidant for polyolefin is applied per 10 g of the polyolefin microporous membrane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62297248A JPH0796627B2 (en) | 1987-11-24 | 1987-11-24 | Polyolefin microporous membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62297248A JPH0796627B2 (en) | 1987-11-24 | 1987-11-24 | Polyolefin microporous membrane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01138245A JPH01138245A (en) | 1989-05-31 |
| JPH0796627B2 true JPH0796627B2 (en) | 1995-10-18 |
Family
ID=17844077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62297248A Expired - Fee Related JPH0796627B2 (en) | 1987-11-24 | 1987-11-24 | Polyolefin microporous membrane |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0796627B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013091059A (en) * | 2011-10-06 | 2013-05-16 | Mitsubishi Rayon Co Ltd | Polyolefin porous hollow fiber membrane and method for producing the same |
| US9660290B2 (en) * | 2003-02-21 | 2017-05-23 | Celgard, Llc | Oxidation resistant separator for a battery |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013054932A1 (en) * | 2011-10-14 | 2013-04-18 | 東レ株式会社 | Porous polypropylene film, layered porous film, and electricity-storage device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1471665A (en) * | 1973-07-03 | 1977-04-27 | Ici Ltd | Dry strippable wall-coverings |
| JPS56159128A (en) * | 1980-05-15 | 1981-12-08 | Asahi Chem Ind Co Ltd | Thermoplastic resin porous film and production thereof |
| JPS61253361A (en) * | 1985-04-15 | 1986-11-11 | Mitsubishi Petrochem Co Ltd | Manufacture of biaxially stretched polypropylene film having vapor-deposited metal |
-
1987
- 1987-11-24 JP JP62297248A patent/JPH0796627B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9660290B2 (en) * | 2003-02-21 | 2017-05-23 | Celgard, Llc | Oxidation resistant separator for a battery |
| US10326121B2 (en) | 2003-02-21 | 2019-06-18 | Celgard, Llc | Oxidation resistant separator for a battery |
| US11482759B2 (en) | 2003-02-21 | 2022-10-25 | Celgard, Llc | Oxidation resistant separator for a battery |
| JP2013091059A (en) * | 2011-10-06 | 2013-05-16 | Mitsubishi Rayon Co Ltd | Polyolefin porous hollow fiber membrane and method for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01138245A (en) | 1989-05-31 |
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