你家里那支护手霜瓶盖的密封圈、墙上打的耐水密封胶、汽车玻璃升降器里那根软弹的密封条——摸上去不粘手、拉不断、晒不黄。背后站着的多半是同一个东西：SEPS。
2025年全球氢化SIS（也就是SEPS）的产能，八成以上攥在五家国外跨国企业手里，国内能做到万吨级量产的掰着手指头数不出三家。这东西用量不大，门槛却高得离谱。可偏偏有一拨做胶粘剂、做热熔胶的厂，正为它的正牌价格头疼。
一只手数得过来的门槛
SEPS，全称苯乙烯-乙烯-丙烯-苯乙烯嵌段共聚物。说人话，它是SIS（苯乙烯-异戊二烯-苯乙烯）加氢之后的产物：把中间那截异戊二烯软段加氢饱和，分子链从怕氧怕热，变成了耐老化、耐臭氧、低温柔韧的材料。
它跟SEBS是同一个加氢体系出来的两种软段结构，区别在于软段——SEPS用的是乙烯-丙烯链段，回弹更柔、阻尼更宽，做胶黏剂和软触感件特别顺手。
全球格局上，按产能和市占排，国外前三把交椅基本是这三家：日本可乐丽（Kuraray，Septon系列）、美国科腾（Kraton，Kraton G系列）、日本旭化成（Asahi Kasei，Tuftec系列）。台橡（TSRC，Taipol）和西班牙Dynasol构成第二梯队，前五大厂合计占全球产能约六成。（口径：产能/市占，行业市场报告）
副牌不是废料，是加氢度飘了一格
那SEPS副牌到底是什么？说白了，跟正牌是同一批聚合产物。SEPS用锂系阴离子聚合，再走加氢工序，工艺波动大，头尾料、牌号切换过渡料、加氢度或门尼粘度小幅越线的批次，检验没踩到正牌线，就成了副牌。
关键要分清：副牌还是原厂原生粒子，分子结构和正牌一个样，只是加氢度、苯乙烯含量或门尼粘度有小幅浮动。它不是回料——回料是你挤出机边角料再造粒，已经吃过一次热历史；更不是再生料——那是废塑料洗了再拉的条子，性能飘得没边。
| 类型 | 来源 | 品质 |
|---|
| 正牌 | 原厂达标批次 | 全指标达标、批次稳 |
| 副牌 | 原厂未达标批次 | 个别指标小幅偏离 |
| 回料 | 加工边角料再造粒 | 已受一次热历史 |
| 再生料 | 废旧塑料回收造粒 | 性能波动大 |
SEPS副牌在热熔胶、密封胶、橡塑共混这些对单指标不敏感的场景，跟正牌的差距，往往就是化验表上的一两格。
可乐丽Septon：色相稳是它的看家活
先说日本可乐丽。这家是做高分子差分起家的，Septon系列在氢化苯乙烯类弹性体里是公认的招牌。它家SEPS牌号体系全，从低硬度到高阻尼都有，做热熔压敏胶和化妆品垫圈是常客。
可乐丽的副牌，多出自牌号切换过渡和加氢度微调的批次。特点是杂质低、色相稳——这对做透明胶、白色密封件的厂很关键。要说短板，就是副牌量少、出柜慢，适合敢备货的老客户。
科腾G系列：化验单敢对着下
再说美国科腾。科腾是SBC（苯乙烯嵌段共聚物）化学的开创者，Kraton G系列就是它的氢化产品招牌。它家在医用级、高端胶粘这块扎根深，SEPS占其氢化产品不小一块。
科腾副牌的特点是牌号文档全、可追溯性强。同一支料正副牌的技术参数能一一对上，采购敢对着化验单下单。它家副线尾料多集中在油含量或门尼粘度的小幅越线，做一般结构胶和橡塑增韧完全顶得住。
旭化成Tuftec：头尾料的性价比
第三家是日本旭化成。它家弹性体走Tuftec和S.O.E.两条线，SEPS也在其中，强项是树脂改性和软触感改性。旭化成的SEPS副牌，多来自装置开停车的头尾料。
这一类料分子结构没话说，就是门尼或加氢度飘一点，做PP增韧、做弹性体共混、做沥青改性这种不挑单指标的活，性价比很突出。要提醒一句：旭化成副牌包装规格杂，大包装小包装都有，下单前先跟供应商确认好料的牌号尾号。
三个坑，踩一个就赔一柜
SEPS副牌看着香，坑也不少。头一个坑，是只看价格不看加氢度。SEPS副牌首先要看的浮动项就是加氢度，加氢度掉一点，耐老化和耐热就跟着掉，做户外件的厂买回来一个夏天就黄变。
再一个坑，是把掺油料当副牌。SEPS副牌是原生粒子，不是掺了环烷油充数的油充胶——那是两个东西，手感像但耐热差一截。还有一个坑，是不留样。副牌批次间有小幅波动，进厂一定要留样打样，测门尼、测扯断、打一炉小试，量产前把配方锁死。
一句话：SEPS副牌买对了是省钱，买错了是把整柜胶往废料堆里倒。
科隆仓库现货｜SEPS全国
主推品牌：可乐丽、科腾、旭化成。
主要牌号：Septon、Kraton G、Tuftec/S.O.E.。
包装规格：小包副牌与箱装副牌走小包装，大包料/吨包料走吨袋，按车间用量分包装备货。
仓库现货：SEPS仓库现货通常在5000吨左右，其中小包副牌备货800-1000吨、箱装副牌备货300-500吨、大包料/吨包料备货3500-3900吨。
供应保障：先测后签，小样过了再走大货。
记五条，再下单
1. 做热熔胶先看门尼和初粘，别只盯硬度。
2. 做透明、白色件，色相和凝胶含量比硬度更要紧。
3. 做户外件，加氢度必须卡线，黄变是红线。
4. 副牌必留样，小试过了再上量产。
5. 大包装小包装先问清，按自己料斗尺寸下单。
九江有家做热熔压敏胶的客户，之前一直用正牌Septon，光胶料成本就占了配方的六成。后来在配方里掺了一成半可乐丽副牌，初粘和持粘测下来跟全正牌只差半个等级，一吨胶料成本压下去八百多块，一年下来省出了两套反应装置的钱。这就是选副牌的价值——不是降品质，是把用不上的那一档指标，换成真金白银。宁波市科隆新材料有限公司做进口弹性体副牌多年，类似的配方搭配每年处理几十起，说白了就是帮你在量产之前把加氢度和门尼这两道关把住。
The sealing ring on your hand cream cap, the water-resistant sealant on the wall, the soft, elastic seal in the car glass regulator—it doesn't stick to the touch, can't be pulled, and doesn't turn yellow when sunburned. Behind it is mostly the same thing: SEPS.
By 2025, over 80% of global hydrogenated SIS (SEPS) production capacity will be held by five foreign multinational companies, and you can count three domestic companies capable of mass production at the 10,000-ton level. This product isn't used in large quantities, but the threshold is ridiculously high. Yet there happens to be a group of factories making adhesives and hot melt adhesives who are struggling with their official prices.
The threshold you can count on one hand
SEPS is Styrene-Ethylene-Propylene-Styrene Block Copolymer. Simply put, it is the product of hydrogenating SIS (Styrene-Isoprene-Styrene): the middle segment of isoprene is saturated with hydrogenation, and the molecular chain changes from being resistant to oxygen and heat to aging-resistant, ozone-resistant, and low-temperature flexible.
It and SEBS are two soft segment structures born from the same hydrogenation system. The difference lies in the soft segment—SEPS uses ethylene-propylene chain segments, which have softer rebound and wider damping, making them especially suitable for making adhesives and soft tactile components.
In terms of global landscape, by capacity and market share, the top three foreign companies are basically these three: Japan's Kuraray (Septon series), America's Kraton (Kraton G series), and Japan's Asahi Kasei (Tuftec series). TSRC (Taipol) and Spain's Dynasol form the second tier, with the top five companies together accounting for about 60% of global capacity. (Basis: capacity/market share, industry market report)
Sub-brand isn't scrap, it's just a level of hydrogen inflated
So what exactly is SEPS sub-brand? To put it bluntly, it's the same batch of polymer products as the real brand. SEPS uses lithium-based anion polymerization followed by hydrogenation processes, which fluctuates greatly. Batches with transition materials, hydrogen content, or Mooney viscosity slightly crossing the line between the head and tail materials and grades fail to meet the genuine brand line become secondary brands.
The key is to distinguish: secondary brands are still original original particles, with molecular structures identical to genuine ones, only slight fluctuations in hydrogenation, styrene content, or Mooney viscosity. It's not recycled material—recycled material is extruded scraps from the extruder edge and repelled, already experiencing a heat history; Nor is it recycled material—that's strips of waste plastic washed and pulled, with poor performance.
| Type | Source | Quality |
|---|
| Genuine Brand | Original Factory Standard Batch | All Indicators Compliant, Batch Stable |
| Subbrand | Original Factory Non-compliant Batch | Slight Deviation in Individual Indicators |
| Recycled Material | Processing Scraps Repelled | Previously Heat-Exposed Past |
| Recycled Material | Recycled Plastic Pelletizing | Large Performance Fluctuations |
SEPS Sub-brands in scenarios where hot melt adhesives, sealants, and rubber-plastic blends are not sensitive to single indicators. The difference from genuine brands is often just one or two bars on the test form.
Septon: Color stability is their specialty .
Let's start with Kuraray Japan. This company started out in polymer differential products, and the Septon series is recognized as a flagship among hydrated styrene elastomers. They have a full SEPS grade system, ranging from low hardness to high damping, and are regulars in hot melt pressure-sensitive adhesives and cosmetic gaskets.
Kuraray's secondary brands mostly come from batch switching, transition, and hydrogen adjustment. The features are low impurities and stable color—this is crucial for factories making transparent adhesives and white seals. The weakness is the small quantity and slow turnout, suitable for long-time customers who dare to stock.
Keteng G Series: Testing reports are straightforward
Let's talk about Keteng from the US. Keton is the pioneer of SBC (Styrene Block Copolymer) chemistry, and the Kraton G series is its flagship hydrogenated product. They have deep roots in medical-grade, high-end adhesives, and SEPS accounts for a significant portion of their hydrogenated products.
Keten's sub-brand features complete grade documentation and strong traceability. The technical parameters of the same raw material and sub-brand can be matched one by one, allowing buyers to place orders directly against the lab reports. Their secondary line tailings are mostly concentrated in oil content or slight deviations in Mooney viscosity, which can withstand general structural adhesives and rubber-plastic toughening.
Asahi Kasei Tuftec: Cost-performance ratio of first and rear materials
The third is Asahi Kasei Japan. Their elastomers follow the Tuftex and S.O.E. lines, including SEPS, with strengths in resin modification and soft touch modification. Asahi Kasei's SEPS sub-brand mostly comes from the start and end materials used in the plant and shutdown.
This type of material has a solid molecular structure, just a bit of moonny or hydrogenation, making PP toughening, elastomer blending, asphalt modification—tasks that don't pick single indicators, but offer outstanding cost-performance. A reminder: Asahi Kasei's secondary packaging specifications vary widely, including large and small packages. Before ordering, confirm the grade and tail number of the quality material with the supplier.
Three pitfalls: step on one and lose an entire cabinet
SEPS The sub-brand looks appealing, but there are plenty of pitfalls. The first pitfall is only looking at price, not hydrogen content. The first thing to check for SEPS sub-brands is hydrogen content. If hydrogen content drops a bit, aging and heat resistance drop, and outdoor goods factories buy it and yellow after just one summer.
Another pitfall is treating oil-doped materials as sub-brands. SEPS sub-brands use virgin particles, not oil-filled glue mixed with naphthenic oil—those are two things, feel similar but have poor heat resistance. There's another pitfall: they don't leave any samples. If there are slight fluctuations between sub-brand batches, you must keep samples for sample testing before entering the factory, testing the meni, testing for tear breakage, and running a batch for a small trial. Before mass production, lock in the formula.
In a nutshell: buying the right SEPS sub-brand saves money; buying the wrong one is dumping the whole container of glue into the waste pile.
Cologne warehouse stock | SEPS nationwide
Main recommended brands: Kuraray, Keteng, Asahi Kasei.
Main brands: Septon, Kraton G, Tuftec/S.O.E.
Packaging specifications: Small sub-brand and boxed sub-brand use small packaging; large package/ton packaging is sold in ton bags, packaged and stocked according to workshop usage.
Warehouse Stock: SEPS warehouse stock is usually around 5,000 tons, with 800-1,000 tons for small packages and sub-brands, 300-500 tons for containerized sub-labels, and 3,500-3,900 tons for large packages/tons.
Supply Assurance: Test before signing, and only after passing small samples do you send out bulk goods.
Note five items before placing an order
1. When making hot melt adhesives, first check the Moonny and initial tack, don't focus only on hardness.
2. For transparent and white products, hue and gel content matter more than hardness.
3. For outdoor products, the hydrogen content must be set up; yellowing is the red line.
4. Sub-brands must keep samples; after small trials, they can be mass-produced.
5. Ask about both large and small packages first, and place orders according to your hopper size.
Jiujiang has a client who makes hot melt pressure-sensitive adhesives. Previously, they always used genuine Septon, and the cost alone accounted for 60% of the formula. Later, they added 15% of the sub-brand to the formula. Initial and long-standing tack tests showed it was only half a level below the full brand, reducing the cost per ton of compound to over 800 yuan, saving the cost of two reaction units in a year. This is the value of choosing a secondary brand—not to lower quality, but to replace the unused standard with real money. Ningbo Kelong New Materials Co., Ltd. has been making imported elastomer sub-brands for many years. Similar formulations handle dozens of cases annually. In short, they help you control hydrogenation and moonny levels before mass production
