プラスチックにおける水酸化マグネシウムの適用

プラスチックにおける水酸化マグネシウムの適用

1. 難燃機能: プラスチックの防火性を強化する

• 難燃機構:
  水酸化マグネシウムは高温で分解します (2mg(おお)₂ → MgO + 2H₂O↑). この過程で大量の熱が吸収されます, プラスチックの表面温度を下げ、熱分解を遅らせることができます。; 分解によって発生する水蒸気は、プラスチックの周囲の酸素と可燃性ガスを希釈する可能性があります。, 燃焼を抑制する; 生成された酸化マグネシウム (MGO) プラスチック表面に緻密な断熱層を形成します。, 熱と酸素をさらに遮断, ～の連鎖効果を達成する “難燃性 – 燃焼抑制 – 自己消火性”.
• 適用可能なプラスチックの種類:
  ポリエチレンなどの各種プラスチックに適しています。 (PE), ポリプロピレン (pp), ポリ塩化ビニル (PVC), ABS樹脂, そしてエポキシ樹脂. 例えば, PE ケーブル材料に水酸化マグネシウムを添加すると、ケーブルが低煙およびハロゲンフリーの難燃性基準を満たすようになります。; PPシートに使用することで、建築・家電分野の耐火性を向上させることができます。.
• 利点:
  従来のハロゲン系難燃剤との比較, 水酸化マグネシウムには次のような特徴があります。 ハロゲンフリー, 低煙, そして毒性が低い. 腐食性ガスを発生しません (ハロゲン化水素など) 燃焼中, EU RoHSに準拠, REACH およびその他の環境規制, のコアマテリアルの 1 つです。 “グリーン難燃性”.

2. 煙の抑制と毒性の軽減: 火災の危険を軽減する

• プラスチックの燃焼中, 水酸化マグネシウムは煙の発生を抑制します, 煙の濃度と有毒ガスの放出を減らす (such as carbon monoxide and nitrogen oxides). This characteristic makes it particularly important in indoor plastics (such as home appliance shells and indoor decorative materials), which can reduce secondary injuries caused by smoke asphyxiation or impaired visibility in fires.

3. Material Modification: Optimizing the Mechanical and Physicochemical Properties of Plastics

• Enhancing Mechanical Properties:
  As an inorganic filler, magnesium hydroxide can combine with the plastic matrix to improve the material’s hardness, rigidity, impact resistance, そして耐摩耗性. 例えば, adding an appropriate amount of surface-modified (such as treated with coupling agents) magnesium hydroxide to PP can improve its flexural strength and heat distortion resistance.
• Improving Heat Resistance and Aging Resistance:
  Magnesium hydroxide has good high-temperature resistance and chemical stability, which can increase the thermal deformation temperature of plastics, delay their aging rate in light, humidity, and heat environments, and extend the service life of products. 例えば, adding it to outdoor plastic pipes and sun visors can enhance their weather resistance.
• Reducing Costs:
  フィラーとして, magnesium hydroxide is relatively low in price. On the premise of not significantly affecting plastic performance, it can partially replace resin, reducing raw material costs.

4. Customized Applications in Specific Fields

• Wire and Cable Industry: In low-smoke and halogen-free cable materials, magnesium hydroxide is the core flame retardant, which can meet the requirements of high flame retardancy and low smoke toxicity of cables, and is widely used in construction, 鉄道輸送, ships and other fields.
• Electronic and Electrical Field: In plastic shells, connectors and other components, magnesium hydroxide can improve the flame retardant grade of materials (UL94Vなど-0), while avoiding corrosion of electronic components by traditional flame retardants.
• Packaging Materials: In plastics for food and pharmaceutical packaging, the non-toxicity and environmental friendliness of magnesium hydroxide make it a preferred additive, which can enhance the safety and heat resistance of packaging materials.

Application Notes

• Surface Modification: Magnesium hydroxide has strong polarity and poor compatibility with non-polar plastics (such as PE and PP). It needs to be surface-treated with silane, titanate and other coupling agents to improve dispersibility and interface bonding force.
• Addition Amount Control: The flame retardant effect increases with the addition amount, but excessive addition will lead to a decrease in the mechanical properties (such as toughness) of plastics. It is necessary to balance flame retardancy and processability according to specific needs.
• Particle Size Selection: Ultra-fine or nano-sized magnesium hydroxide can reduce the negative impact on plastic performance and improve flame retardant efficiency, but the cost is higher, so it should be selected according to the application scenario.

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