一批电子外壳送UL实验室测试，离火后继续燃烧，V-0等级没拿到。北美客户的订单直接黄了，研发总监在实验室坐了一整夜——溴系阻燃剂加了12%，但三氧化二锑协效剂只加了2%，比例不对，自由基捕捉不充分，等于防火墙只砌了一半。
塑料不阻燃，就像纸房子里点蜡烛，验收那天UL94一把火全露馅。
本文由长期经营塑料原料及助剂的宁波市科隆新材料有限公司整理，牌号与批次信息以实际供货渠道为准。
阻燃剂速查总表：溴系磷系氮系无卤四条路线
阻燃剂按化学路线分四大类：溴系高效成熟、磷系氮系走无卤、金属氢氧化物无卤但要高填充。选型先定路线——要不要无卤、做哪种基材、阻燃等级要求多少，再回头选具体品种。
| 体系 | 代表品种 | 阻燃机理 | 典型制品 | 添加比例 |
|---|
| 溴系+协效 | 十溴二苯乙烷+Sb2O3 | 气相捕捉自由基 | 电子电器、玻纤增强 | 8%-15% |
| 磷系 | 红磷、聚磷酸铵、次磷酸铝 | 凝聚区成炭 | PP、PA、PET阻燃 | 10%-20% |
| 氮系 | 三聚氰胺及其盐 | 气相稀释、成炭 | PA、PP膨胀型 | 10%-20% |
| 无卤协效 | 磷系+氮系+氢氧化铝/镁 | 气相+凝聚区协同 | 无卤电缆、新能源 | 15%-30% |
| 金属氢氧化物 | 氢氧化铝、氢氧化镁 | 吸热、稀释、成炭 | 无卤低烟、建材 | 30%-60% |
注：以上阻燃等级和添加量为行业参考，实际阻燃效果以UL官方黄卡和第三方检测为准。阻燃剂添加量大，是成本敏感项，且常导致力学下降，配方要刚韧阻燃一起算。
图1 阻燃剂——塑料表面的防火屏障
阻燃剂就是塑料身上的防火墙，烧起来替你挡那一下
这位主角，是塑料的防火墙。宁波市科隆新材料有限公司长期经营各类塑料助剂及改性原料，覆盖国内外多个品牌货源，在溴系、磷系、氮系及无卤协效阻燃体系上有稳定供货。阻燃剂这个品类，本质上是塑料的“防火墙”。塑料遇火会分解出可燃气体、维持链式燃烧，阻燃剂的作用就是打断这个链条，要么在气相里捕捉自由基、把火压下去，要么在材料表面成炭、把氧气和热量挡在外头。
阻燃不是加得越多越安全，协效比例和分散到位，真烧起来它才替你挡得住那一下。
拿溴系+三氧化二锑（Sb2O3）协效来说，十溴二苯乙烷受热释放出溴化氢等气体，Sb2O3和它反应生成更高效的气相阻燃物种，两者1+1大于2，这就是“协效”。无卤路线则靠磷系在凝聚区催化成炭、氮系在气相稀释可燃气体、金属氢氧化物吸热降温和释放水汽，几路一起下手。机理上各有侧重，不是随便堆。
溴系阻燃剂受热释放出捕捉自由基的气体，像在火焰外面织了一张看不见的灭火网。
一个常见误区：阻燃剂加得越多等级越高。实际上阻燃剂过量会严重牺牲力学、流动和耐候，还可能析出；而不加协效剂，单靠溴系或单靠磷系，效率大打折扣。行业里的共识是：复配协效，用更小的添加量达到同样等级，才是真功夫。
哦，你说“阻燃”？离火就着、离火还烧，那叫烧得挺旺，不叫阻燃。
逐品种速查：溴系配Sb2O3，无卤走磷氮氢氧化物
阻燃剂牌号众多，抓住四条主线即可。下面逐个讲清定位和注意事项。
选阻燃路线像选消防通道：无卤还是溴系，开工前就得定，烧到一半再改方向，来不及了。
十溴二苯乙烷+三氧化二锑：溴系阻燃的经典组合，效率高、成本相对可控，广泛用于玻纤增强PP/PA和电子电器件。溴锑比例常见约3:1。选它的信号：对成本敏感、基材允许用卤系、要稳定过UL94 V-0。注意：含卤，出口和无卤要求件不能用；Sb2O3有一定使用限制，要查法规。
供货提示：溴系、磷系、氮系阻燃剂科隆新材可配套供货，每批附阻燃等级参考数据，公斤级试样支持先做UL预测试。
磷系阻燃剂（红磷、聚磷酸铵、次磷酸铝）：走无卤路线的主力，靠凝聚区成炭。红磷阻燃效率高但要注意颜色和安全；聚磷酸铵多用于膨胀型；次磷酸铝适合PA、PBT等玻纤增强体系。选它的信号：无卤要求、需要较高阻燃等级。注意：磷系对加工温度和水解敏感，PA/PB要充分干燥。
无卤不是少加点溴那么简单，它是气相、凝聚区、吸热三路兵马一起上，缺一路就漏风。
氮系阻燃剂（三聚氰胺及其盐）：主要用于PA和PP，靠气相释放不燃气体和膨胀成炭。常和磷系组成膨胀型阻燃体系。选它的信号：无卤、PA/PP阻燃。注意：氮系高温可能分解放氨，加工和气味要评估。
金属氢氧化物（氢氧化铝、氢氧化镁）：真正无卤低烟，但阻燃效率低，要加到30%-60%才够，会显著增加密度、牺牲力学和流动。适合对烟密度、无卤要求高的电缆、建材。选它的信号：无卤低烟电缆、建材。注意：高填充，必须配偶联剂改善界面。
无卤协效复配体系：把磷系、氮系、金属氢氧化物按比例复配，兼顾效率与无卤，是新能源、无卤电缆的方向。选它的信号：无卤+较高阻燃+力学可接受。注意：复配体系要按厂家推荐比例，自己乱配容易阻燃不达标。
阻燃剂加进去，料性会降、成本会涨，这是它的脾气，提前有心理准备就不慌。
替代对照：进口阻燃体系换国产，先过UL94
采购常问：进口阻燃剂能不能国产替代？答案是通用溴系和无卤体系差距已小，但阻燃等级测试和法规合规是硬门槛，必须实测。阻燃剂关键是有效成分含量和协效比例，国产主流品牌已能对标。下面这张表列出常见替代方向和切换前提。
| 原用进口方向 | 典型应用 | 可对标方案 | 切换前提 |
|---|
| 进口溴系阻燃剂 | 电子电器、玻纤增强 | 国产十溴二苯乙烷+Sb2O3 | 对比UL94等级、力学、析出 |
| 进口红磷/磷系 | PA/PET无卤阻燃 | 国产磷系阻燃剂 | 对比阻燃等级、水解、颜色 |
| 进口膨胀型氮磷体系 | PP无卤 | 国产磷氮协效 | 对比成炭、烟密度、加工窗口 |
| 进口无卤协效体系 | 新能源、无卤电缆 | 国产磷氮+氢氧化物复配 | 对比UL94、GWIT、力学保留 |
| 进口氢氧化镁/铝 | 低烟无卤电缆 | 国产金属氢氧化物 | 对比氧指数、密度、界面 |
表中为应用方向参考，不代表性能完全等同。替代顺序：小试→UL94平行测试→客户书面确认→小批量→放量。
阻燃剂替代必须过UL预测试，科隆新材寄送公斤级试样时可配套提供阻燃等级参考和卤素合规文件，客户先做内部燃烧测试再送第三方，节省认证周期。
为了省阻燃剂多加两三成填料，结果阻燃等级不达标、整批退货，这买卖亏到姥姥家。
行业场景速查：阻燃等级跟着安规走
同样是阻燃剂，做电子连接器和做无卤电缆，体系和法规完全不同。下面这张表按行业拆解。
| 行业 | 典型制品 | 客户最先问的参数 | 推荐方案 | 认证要求 |
|---|
| 电子电器 | 连接器、开关、线圈骨架 | UL94等级、GWIT、CTI | 溴系+Sb2O3或无卤磷系 | UL黄卡、RoHS |
| 汽车 | 内饰、线束、电池周边 | 低烟、无卤、热老化 | 无卤磷氮协效 | IATF 16949、ECE R118 |
| 电缆 | 建筑线、控制线、光伏线 | 氧指数、烟密度、无卤 | 氢氧化物/无卤协效 | GB/T 19666、IEC |
| 新能源 | 电池包结构件、支架 | 无卤、阻燃、低毒 | 无卤磷系+协效 | UL94、整车厂规范 |
| 建材 | 管材、装饰板 | 阻燃、烟密度 | 氢氧化物/膨胀型 | GB 8624 |
| 家电 | 外壳、内部件 | UL94、耐热 | 溴系或无卤 | UL、RoHS |
举个具体场景：做新能源电池包周边无卤支架，要求UL94 V-0、无卤、低烟。这时走磷系+氮系+少量金属氢氧化物复配，添加量约15%-25%，同时配POE类增韧剂补回阻燃剂拉低的冲击，阻燃和刚韧一起调。
添加量与搭配要点：复配协效，别单点堆料
阻燃剂是助剂里用量最大的，复配协效能用更小添加量达到目标等级。下面四个配方覆盖主流路线。
无卤趋势下，早把磷氮协效体系摸熟，比临时换配方从容得多。
◆ 溴系玻纤增强：十溴二苯乙烷12%-14%+Sb2O3约3%-5%，用于PP/PA电子件，目标UL94 V-0。
◆ PA无卤：次磷酸铝/磷系10%-15%，PA充分干燥，注意水解和析出。
◆ PP无卤膨胀型：磷系+氮系复配15%-20%，靠成炭阻燃，注意加工温度窗口。
◆ 无卤低烟电缆：氢氧化铝/镁30%-60%，配偶联剂改善界面，配增韧剂补冲击。
搭配要点三条：一是阻燃剂常和增韧剂一起用，因为阻燃剂会降冲击，POE类补回来；二是溴系阻燃剂在高温下可能消耗抗氧剂，要适当补抗氧；三是玻纤增强件做阻燃要注意，玻纤会“烛芯效应”助长燃烧，阻燃剂用量要比无玻纤体系更多。
阻燃剂最怕采购只看价格不看UL黄卡，烧起来才想起合规那本账。
阻燃：复配协效。
加工与合规红线：析出、水解、UL黄卡
阻燃剂用不好，不是析出就是阻燃不达标。下面这张表把关键参数和做错的后果列出来。
| 环节 | 参考值 | 做错的后果 |
|---|
| 阻燃剂分散 | 高速混合均匀、必要时造粒母粒 | 分散不均→局部阻燃不达标 |
| 含磷体系烘干 | PA/PBT 80-120℃×4-8h | 未烘干→水解、阻燃效率下降 |
| 加工温度 | 按基材，避免阻燃剂过早分解 | 温度过高→阻燃剂分解、气味 |
| 协效比例 | 溴:锑约3:1，按厂家推荐 | 比例失衡→阻燃效率低、成本高 |
| 合规归档 | UL黄卡、RoHS、REACH、烟密度 | 无文件→客户不认、出货卡壳 |
合规红线：电子件要UL94黄卡和GWIT/CTI；出口欧盟要REACH（部分溴系阻燃剂如多溴联苯醚类受限制）；汽车件要整车厂阻燃和低烟规范；无卤件要符合对应无卤和烟密度标准。合规文件随货索取归档。
FAQ：采购和配方工程师常问的五个问题
Q1：国产阻燃剂能不能替代进口料？
可以，但阻燃是硬测试。通用溴系和常规无卤体系，国产主流牌号和进口差距已小，批次稳定的国产品牌能替代。但在新能源无卤、高端电子UL黄卡、低烟无卤等场景，进口牌号在协效配方和批次一致性上仍有优势。正确做法是先拿公斤级样品做UL94平行测试，对比等级、GWIT和力学保留，通过后小批量再放量。测试用的对照样品，可以找科隆新材按公斤级索取，附批次数据一并比对。
Q2：阻燃剂加了为什么还过不了V-0？
先查三点：一是没加协效剂，单剂效率不够；二是玻纤的烛芯效应放大了燃烧，用量不足；三是分散不均或阻燃剂在加工中分解。复配协效、核比例、控温度，往往比单纯多加更管用。
Q3：溴系和无卤怎么选？
看客户要求和法规。允许卤系、成本敏感、要稳定V-0，溴系+Sb2O3性价比高；客户明确无卤、出口受限、新能源方向，走磷氮协效或金属氢氧化物。别在无卤件上用溴系，也别在成本敏感件硬上高填充氢氧化物。
Q4：阻燃剂会不会让材料变脆？
会，尤其无卤氢氧化物高填充体系。对策是配POE类增韧剂和偶联剂改善界面，把损失的冲击补回来，刚韧阻燃三者一起平衡。
Q5：阻燃剂什么价位？
常用价格带差异较大，溴系约15-40元/kg、磷系约20-60、氮系约20-50、氢氧化铝约5-15、氢氧化镁约10-25，随行情波动，以当期报价为准。阻燃剂添加量大，是配方成本的大头，选对协效配方比砍单价更重要。
选型三步清单：照做不踩坑
◆ 第1步·定路线：先确认要不要无卤、目标UL94等级、基材和有无玻纤，再定溴系协效还是磷氮/氢氧化物路线。
◆ 第2步·定配方：按路线定阻燃剂与协效剂比例（溴:锑约3:1等），评估对力学和流动的影响，必要时配增韧剂和偶联剂。
◆ 第3步·过测试：做UL94、GWIT、烟密度平行测试，确认等级达标，再按用途核对UL黄卡、RoHS、REACH并归档。
UL黄卡拿到手，订单才睡得着
阻燃剂选型要同时考虑阻燃等级、基材相容性、合规要求和成本。科隆新材供应溴系（十溴二苯乙烷+Sb2O3协效）、磷系（BDP/RDP）、氮系（MCA）及无卤协效体系，可提供UL黄卡参考和RoHS/REACH合规文件；不同基材（PP/ABS/PC/PA）可推荐对应体系，公斤级试样支持先做阻燃预测试再定配方。
那是去年，一家做电子连接器的厂要冲北美市场，UL94 V-0测试两次都没过。科隆吴经理看了他们的配方，溴系加了12%但Sb2O3只有2%，协效比例不对。建议调到溴系约10%+Sb2O3约4%，并补充了抗氧剂防止阻燃剂加工降解，寄了对应样品。客户第三次送测通过了V-0，拿到UL黄卡后北美订单顺利落地。研发总监说，原来不是加得越多越阻燃，是比例得对。
溴系和三氧化二锑，你的比例是几比几？
声明：本文涉及的品牌、商标及产品名称权归各自原厂所有。本文为第三方选材知识分享，文中提及的牌号、参数、价格、认证及应用案例仅供参考，具体以各生产企业官方最新资料及批次检测报告为准。本文不构成任何采购或投资建议，读者据此操作风险自担。
A batch of electronic casings was sent to UL lab for testing, but after de-ignition, it continued to burn, but did not receive V-0 rating. The North American customer's order was immediately rejected. The R&D director sat in the lab all night—bromin-based flame retardant was added, but antimony trioxide synergist only added 2%, the ratio was incorrect, free radical capture was insufficient, meaning only half the firewall was built.
Plastic is not flame-retardant, like lighting a candle in a paper house; on the day of acceptance, UL94 was completely exposed by a fire.
This article was compiled by Ningbo Kelong New Materials Co., Ltd., a long-term business in plastic raw materials and additives. Grade and batch information are subject to actual supply channels.
Flame Retardant Quick Reference Summary: Bromine, phosphorus, nitrogen-based, and halogen-free routes
Flame retardants are divided into four main categories by chemical route: bromine based is highly efficient maturing, phosphorus and nitrogen is halogen-free, and metal hydroxides are halogen-free but require high filling. When selecting a model, first decide the route—whether halogen-free is needed, which substrate to use, what flame retardant rating is required, and then choose the specific variety.
| System | Representative Varieties | Flame Retardant Mechanism | Typical Products | Added Ratio |
|---|
| Bromine Series + Synergistic | Decabromodiphenylethane + Sb2O3 | Vapor Phase Free Radical Capturer | Electronics and Electrical Appliances, Glass Fiber Reinforcement | 8%-15% |
| Phosphorus-based | Red phosphorus, polyammonium phosphate, aluminum hypophosphite | Coagulated zone carbon-forming | PP, PA, PET flame retardant | 10%-20% |
| Nitrogen-based | Melamine and its salts | Vapor dilution, carbon-forming | PA, PP expansion type | 10%-20% |
| halogen-free synergy | Phosphorus + nitrogen-based + aluminum hydroxide/magnesium | Vapor phase + cohesive zone synergy | halogen-free cable, new energy | 15%-30%. |
| Metal Hydroxides | Aluminum hydroxide, magnesium hydroxide | Heat absorption, dilution, carbon formation | Halogen-free and low smoke, Building materials | 30%-60% |
Note: The above flame retardant grades and additive amounts are industry references; actual flame retardant effects are subject to UL official yellow cards and third-party testing. Large amounts of flame retardants are added, making them cost-sensitive and often leading to mechanical degradation. Formulas must be tough and flame-retardant together.
Figure 1 Flame retardants — the fire barrier on plastic surfaces
Flame retardants are the firewall on plastics; when they burn, they shield you from that attack.
The protagonist is the firewall of plastics. Ningbo Kelong New Materials Co., Ltd. has long operated various plastic additives and modified raw materials, covering multiple domestic and international brands, with stable supply in bromine-based, phosphorus-based, nitrogen-based, and halogen-free synergistic flame retardant systems. Flame retardants are essentially the "firewall" of plastics. Plastic decomposes into combustible gases when exposed to fire, maintaining chain combustion. The function of flame retardants is to break this chain—either trapping free radicals in the gas phase to suppress the flame, or carbonizing the material surface to keep oxygen and heat out.
Flame retardant isn't just about adding more to get safer. When the synergistic ratio and dispersion are in place, only when it really burns can it withstand that moment.
Take brominated + antimony trioxide (Sb2O3) synergy: when decabromodiphenylethane is heated, it releases gases like hydrogen bromide. Sb2O3 reacts with it to form more efficient gas-phase flame-retardant species. The ratio of 1+1 is greater than 2—that's 'synergy.' The halogen-free route relies on phosphorus-based catalytic carbonization in the cohesive zone, nitrogen-based gas dilution in the gas-phase phase, metal hydroxides absorbing heat for cooling, and releasing water vapor—working on multiple approaches simultaneously. Each mechanism has its own focus; it's not just random stacking.
Bromine-based flame retardants release gases that trap free radicals when heated, like weaving an invisible fire net outside the flame.
A common misconception: the more flame retardants added, the higher the grade. In fact, excessive flame retardants seriously sacrifice mechanics, flow, and weather resistance, and may even precipitate; Without adding synergists, relying solely on bromine-based or phosphorus-based systems greatly reduces efficiency. The industry consensus is: blending synergy—achieving the same grade with a smaller amount is the real skill.
Oh, you mean "flame retardant"? If you burn as soon as you leave the flame, or burn after leaving the flame, that's called burning quite strong, not flame retardant.
Quick product search: bromine-based with Sb2O3, halogen-free with phosphorus, nitrogen, and hydroxide
There are many types of flame retardants; just focus on the four main lines. Next, I'll explain the positioning and precautions one by one.
Choosing a flame-retardant route is like choosing a fire lane: whether halogen-free or bromine-based must be decided before work starts, and changing direction halfway through burning is too late.
Decabromodiphenylethane + antimony trioxide: A classic bromine-based flame-retardant combination, high efficiency and relatively controllable cost, widely used in glass fiber reinforced PP/PA and electronic electrical devices. The bromide antimony ratio is commonly about 3:1. Signal for choosing it: Cost-sensitive, halide-based substrates allowed, must be stable above UL94 V-0. Note: Halogen-containing and halogen-free parts must not be used; Sb2O3 has certain usage restrictions, so please check regulations.
Supply Tip: Bromine-based, phosphorus-based, and nitrogen-based flame retardants Kelon New Materials can supply supporting supply. Each batch includes reference data for flame retardant ratings, and kilogram-level samples support UL pre-testing first.
Phosphorus-based flame retardants (red phosphorus, polyammonium phosphate, aluminum hypophosphite): The main product for halogen-free routes, relying on coagulation zone carbonization. Red phosphorus has high flame retardant efficiency but must pay attention to color and safety; Polyammonium phosphate is mostly used for expansion types; Aluminum hypophosphite is suitable for glass fiber reinforced systems such as PA and PBT. Choose its signal: halogen-free and require a high flame retardant rating. Note: Phosphorus-based products are sensitive to processing temperature and hydrolysis; PA/PB must be thoroughly dried.
Halogen-free is not just about adding a little bromine; it involves the vapor phase, condensation zone, and heat absorption all working together; any one will leak air.
Nitrogen-based flame retardants (melamine and its salts): mainly used for PA and PP, releasing non-combustible gases and expanding into carbon in the gas phase. They often form intumescent flame-retardant systems with phosphorus-based systems. Signal when selecting: halogen-free, PA/PP flame-retardant. Note: Nitrogen-based flame retardants may be separated from ammonia at high temperatures; processing and odor must be evaluated.
Metal Hydroxides (aluminum hydroxide, magnesium hydroxide): Truly halogen-free with low smoke, but low flame retardancy efficiency, requiring 30%-60% to be sufficient, significantly increasing density, sacrificing mechanics and flow. Suitable for cables and building materials with high requirements for smoke density and halogen-free. Choose its signal: halogen-free, low-smoke cables and building materials. Note: High filling, must be coupling to improve interface.
Halogen-free synergistic blending system: Mix phosphorus, nitrogen, and metal hydroxides in proportion, balancing efficiency and halogen-free, which is the direction for new energy and halogen-free cables. Choose its signal: halogen-free + higher flame retardancy + mechanically acceptable. Note: The blending system should follow the manufacturer's recommended ratio; random mixing may cause flame retardancy and substandard standards.
Adding flame retardants reduces material properties and increases costs. This is their temperament; if you are mentally prepared in advance, you won't panic.
Substitution Comparison: Switching from imported flame retardant systems to domestic ones first passes UL94
Procurement FAQ: Can imported flame retardants be replaced domestically? The answer is that the gap between general bromine and halogen-free systems has narrowed, but flame retardant rating testing and regulatory compliance are hard hurdles and must be tested. The key to flame retardants is the content of active ingredients and the synergistic ratio, which mainstream domestic brands can already match. The table below lists common substitution directions and switching prerequisites.
| Original imported direction | Typical applications | Benchmarkable solutions | Switching prerequisites |
|---|
| Imported brominated flame retardants | Electronics and electrical appliances, glass fiber reinforcement | Domestic decabromodiphenylethane + Sb2O3 | Comparison of UL94 rating, mechanical properties, and precipitation |
| Imported red phosphorus/phosphorus-based | PA/PET Halogen-Free Flame Retardant | Domestic phosphorus-based flame retardant | Compare flame retardant grade, hydrolysis, color |
| Imported expandable nitrogen-phosphorus system | PP halogen-free | Domestic phosphorus-nitrogen synergistic effect | Comparison of carbonization, smoke density, and processing window |
| Imported halogen-free synergistic system | New energy, halogen-free cables | Domestic phosphonitride hydroxide compound | Comparison of UL94, GWIT, and mechanical retention |
| Imported magnesium/aluminum hydroxide | Low-smoke halogen-free cable | Domestic metal hydroxide | Comparison of oxygen index, density, and interface |
The table is for application reference and does not imply complete equivalence in performance. Replacement sequence: lab scale → UL94 parallel testing → customer written confirmation → small batch → mass production.
Flame retardant substitutes must pass UL pre-testing. When Cologne New Materials sends kilogram-scale samples, they can provide flame retardant grade references and halogen compliance documents. Customers can first conduct internal burn tests before sending to a third party, saving certification time.
In order to save on flame retardant, they added 20–30% more filler, but as a result, the flame retardant level didn't meet the standard, and the whole batch was returned. This deal ended up being a complete loss.
Industry Scenario Quick Lookup: Flame Retardant Ratings Follow Safety Standards
Even though they are both flame retardants, the systems and regulations are completely different for electronic connectors and halogen-free cables. The table below breaks this down by industry.
| Industry | Typical products | The parameters the customer asked about first | Recommended plan | Certification requirements |
|---|
| Electronics and electrical appliances | Connectors, switches, coil cores | UL94 rating, GWIT, CTI | Bromine-based Sb2O3 or halogen-free phosphorus-based | UL Yellow Card, RoHS |
| Car | Interior, wiring harness, battery perimeter | Low smoke, halogen-free, thermal aging | Halogen-free phosphorus-nitrogen synergism | IATF 16949, ECE R118 |
| Cable | Building lines, control lines, photovoltaic lines | Oxygen index, smoke density, halogen-free | Hydroxide/halogen-free synergistic effect | GB/T 19666, IEC |
| new energy | Battery pack structural components, brackets | Halogen-free, flame-retardant, low-toxicity | Halogen-free phosphorus-based synergist | UL94, OEM specifications |
| Building materials | Pipes and decorative panels | Flame retardant, smoke density | Hydroxide/Expandable | GB 8624 |
| Home appliances | Shell, internal components | UL94, heat resistance | Brominated or halogen-free | UL, RoHS |
Here's a specific scenario: making halogen-free brackets around new energy battery packs, requiring UL94 V-0, halogen-free, and low smoke. At this point, phosphorus-based, nitrogen-based, and a small amount of metal hydroxides are used in a compound, with an addition of about 15%-25%. At the same time, POE-type toughening agents are added to compensate for the impact reduction caused by the flame retardants, adjusting flame retardancy and rigidity-toughness together.
Dosage and matching points: synergistic blending, avoid piling ingredients at a single point
Flame retardants are the additives used in the largest amounts, and synergistic formulations can achieve the target level with even smaller additions. The following four formulations cover the mainstream routes.
Under the halogen-free trend, it's much better to become familiar with the phosphorus-nitrogen synergistic system early rather than switching formulas at the last minute.
◆ Brominated glass fiber reinforced: Decabromodiphenyl ethane 12%-14% Sb2O3 about 3%-5%, used for PP/PA electronic parts, target UL94 V-0.
◆ Halogen-free PA: Aluminum hypophosphite/phosphorus-based 10%-15%, PA should be thoroughly dried, pay attention to hydrolysis and precipitation.
◆ Halogen-free expandable PP: Phosphorus-based and nitrogen-based compounds 15%-20%, flame retardancy relies on char formation, pay attention to processing temperature window.
◆ Halogen-free low-smoke cable: 30%-60% aluminum/magnesium hydroxide, with a coupling agent to improve the interface, and with an impact modifier to enhance toughness.
Three key points for formulation: First, flame retardants are often used together with toughening agents because flame retardants reduce impact strength, which POE-type agents can compensate for; second, brominated flame retardants may consume antioxidants at high temperatures, so appropriate antioxidant supplementation is needed; third, for glass fiber reinforced parts, special attention is needed when making them flame retardant, as glass fibers can create a 'wick effect' that promotes burning, so the amount of flame retardant needs to be higher than in non-glass fiber systems.
Flame retardants fear procurement that only looks at price and ignores the UL yellow card; only when it catches fire do they remember the compliance account.
Flame retardant: compounded synergistic effect.
Processing and Compliance Red Lines: Precipitation, Hydrolysis, UL Yellow Card
If flame retardants are not used properly, they either precipitate or fail to meet the flame retardancy standards. The table below lists the key parameters and the consequences of mistakes.
| link; segment; part | Reference value | The consequences of doing wrong |
|---|
| Flame retardant dispersion | High-speed mixing until uniform, granulate masterbatch if necessary | Uneven dispersion → Local flame retardancy not up to standard |
| Phosphorus-containing system drying | PA/PBT 80-120℃ × 4-8h | Not dried → decreased hydrolysis and flame retardant efficiency |
| Processing temperature | According to the substrate, avoid premature decomposition of the flame retardant | Excessive temperature → flame retardant decomposition, odor |
| synergy ratio | Bromine:antimony about 3:1, according to the manufacturer's recommendation | Imbalanced ratio → low flame retardant efficiency, high cost |
| Compliance Archiving | UL Yellow Card, RoHS, REACH, Smoke Density | No documents → Customer does not acknowledge, shipping stalls |
Compliance Red Lines: Electronic parts must have UL94 yellow card and GWIT/CTI; exports to the EU require REACH (some brominated flame retardants such as polybrominated biphenyl ethers are restricted); automotive parts must meet the vehicle manufacturer's flame retardant and low smoke standards; halogen-free parts must comply with the corresponding halogen-free and smoke density standards. Compliance documents should be requested with the goods for filing.
FAQ: Five Common Questions Asked by Procurement and Formulation Engineers
Q1: Can domestic flame retardants replace imported materials?
It's possible, but flame retardancy is a strict test. For general brominated and conventional halogen-free systems, the gap between mainstream domestic brands and imported ones is already small, and stable domestic brands can be used as replacements. However, in scenarios like new energy halogen-free materials, high-end electronic UL yellow card, and low-smoke halogen-free materials, imported grades still have advantages in synergistic formulation and batch consistency. The correct approach is to first perform parallel UL94 testing with kilogram-level samples, comparing ratings, GWIT, and mechanical property retention, and after passing, scale up with small batches. For reference samples for testing, you can request kilogram-level samples from Cologne New Materials and compare them along with the batch data.
Q2: Why does it still fail to pass V-0 even after adding flame retardant?
Check three points first: one, no synergist was added, so the efficiency of a single agent is insufficient; two, the candlewick effect of the glass fiber amplifies burning, and the amount is insufficient; three, uneven dispersion or decomposition of the flame retardant during processing. Using a compounded synergist, adjusting the core ratio, and controlling the temperature are often more effective than simply adding more.
Q3: How to choose between brominated and halogen-free?
Look at customer requirements and regulations. If halogenated materials are allowed, cost-sensitive, and need stable V-0, brominated Sb2O3 has a high cost-performance ratio; if the customer explicitly requires halogen-free, has export restrictions, or is in the new energy sector, use phosphorus-nitrogen synergistic or metal hydroxides. Do not use brominated materials in halogen-free parts, and do not force high-filled hydroxides in cost-sensitive parts.
Q4: Will flame retardants make the material brittle?
Yes, especially in halogen-free highly filled hydroxide systems. The strategy is to use POE-type toughening agents and coupling agents to improve the interface, compensating for the lost impact, and balance rigidity, toughness, and flame retardancy together.
Q5: What is the price range of flame retardants?
Common price ranges vary greatly: brominated around 15-40 yuan/kg, phosphorus-based around 20-60, nitrogen-based around 20-50, aluminum hydroxide around 5-15, magnesium hydroxide around 10-25, fluctuating with market conditions and subject to current quotations. The amount of flame retardant added is large, making it a major part of the formulation cost; choosing the right synergistic formulation is more important than cutting the unit price.
Three-Step Selection Checklist: Follow It Without Pitfalls
◆ Step 1 · Set the route: First confirm whether it should be halogen-free, the target UL94 rating, the substrate, and whether it contains fiberglass, then decide on a bromine-based synergistic approach or a phosphorus-nitrogen/hydroxide route.
◆ Step 2 · Formulate: Determine the ratio of flame retardant to synergist according to the route (bromine:antimony about 3:1, etc.), evaluate the impact on mechanical properties and flow, and add toughening agents and coupling agents if necessary.
◆ Step 3·Pass Testing: Conduct UL94, GWIT, and smoke density parallel tests to confirm that the rating meets the standard, then verify the UL Yellow Card, RoHS, and REACH according to the intended use and file the records.
I can only sleep after I get the UL yellow card in hand and the order confirmed.
The selection of flame retardants should simultaneously consider the flame retardant level, substrate compatibility, compliance requirements, and cost. Kolon New Materials supplies brominated systems (decabromodiphenyl ethane with Sb2O3 synergist), phosphorus-based systems (BDP/RDP), nitrogen-based systems (MCA), and halogen-free synergistic systems, and can provide UL Yellow Card references as well as RoHS/REACH compliance documents. Different substrates (PP/ABS/PC/PA) can be recommended with corresponding systems, and kilogram-scale samples are supported for preliminary flame retardant testing before finalizing the formulation.
That was last year. A factory producing electronic connectors wanted to enter the North American market, but their UL94 V-0 test failed twice. Manager Wu from Cologne looked at their formula and saw that they had added 12% brominated compounds, but only 2% Sb2O3, so the synergistic ratio was incorrect. He suggested adjusting it to about 10% brominated compounds and about 4% Sb2O3, and added antioxidants to prevent degradation of the flame retardants during processing, and sent the corresponding samples. On the third test, the client passed V-0. After receiving the UL yellow card, their North American orders went through smoothly. The R&D director said that it turns out that more is not always better for flame retardancy; the proportion has to be right.
For bromine compounds and antimony trioxide, what is your ratio?
Statement: The brands, trademarks, and product names mentioned in this article are owned by their respective original manufacturers. This article is a third-party material selection knowledge sharing; the grades, parameters, prices, certifications, and application cases mentioned are for reference only. Specific information should be based on the latest official data and batch inspection reports from the respective manufacturers. This article does not constitute any procurement or investment advice, and readers bear the risks of any actions taken based on it.
