做热熔胶的都知道,SEBS牌号选错,胶一撕就分层——一吨胶料没省下来,客户的退货单先到了。
SEBS是SBS加氢之后的产物,耐候、耐热、不黄变,做热熔压敏胶、密封剂、改性TPE都离不开它。可它正牌不便宜,一柜料压下来,胶厂的利润就薄了一截。
问题是SEBS副牌水更深:线性还是星型、苯乙烯含量多高、油充没充,差一点,胶的初粘、持粘、耐温全变。说白了,不是SEBS副牌不能用,是你没把它的牌号脾气摸透。
这篇把SEBS讲透:它和SBS到底差在哪,全球前三是哪几家,做胶做密封该怎么挑副牌。
把SBS加氢,胶就耐候不黄变
SEBS是苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物,本质就是把SBS中间的双键加氢饱和掉。加氢之后,耐紫外线、耐热、抗黄变能力上一个台阶,不用硫化就能用,回收也方便。做热熔胶、密封剂、塑料改性增韧、软触感TPE,都靠它。
做胶的圈子里常说:要耐候、要耐温、要不黄变,选SEBS;图便宜、室内短期用,才用SBS。
全球SEBS格局,头部集中:美国科腾(Kraton)常年领跑,手里的Kraton G系列是SBC行业的标杆;日本旭化成的Tuftec®是透明和医用级主力;中国台湾台橡(TSRC)的Taipol®在胶黏剂和改性上走量。日本可乐丽Septon®在第二梯队。三家都在非中国大陆。
副牌是同一支加氢聚合物,只是化验单某格浮动
SEBS副牌,是同一厂、同一牌号里,苯乙烯含量、门尼粘度或流动指标出厂检验小幅偏离的批次。加氢后的分子结构和正牌一致,还是原厂原生胶粒。
四条来源不变:开停车头尾料、牌号切换过渡料、工艺波动致单项超标的批次、副线尾料。
边界要分清:正牌全指标达标;副牌单项小幅浮动;回料是胶粒混炼后的边角再造粒,已经受过热历史,性能打折;再生料波动大。SEBS做胶怕苯乙烯含量和粘度飘——这俩直接决定初粘和持粘,飘了胶就分层。
副牌主题金句:SEBS副牌买错牌号,做出来的热熔胶一到冬天就脆、撕开就掉,一整批密封剂当场报废。
科腾:Kraton G,SBC行业的标杆
科腾是苯乙烯嵌段共聚物的老大哥,Kraton G系列牌号细分极细,做胶、做改性都能对上号。它的副牌多是粘度或苯乙烯含量小幅偏离的批次,基材一致。
做普通密封剂、非耐候要求的胶黏剂,挑它的精选副牌,成本能压下一块。
旭化成:Tuftec®,透明和医用级的主力
旭化成的Tuftec®在高透明、医用级SEBS上口碑很硬,做透明TPE和高要求胶黏剂用得多。它的副牌色相和透明度控制得细,做对透明要求不高的胶和改性件很稳。
台橡:Taipol®,胶黏剂市场的走量王
台橡是台湾SBC大户,Taipol® SEBS在热熔胶、沥青改性、塑料增韧上走量很大,供货稳。它的副牌批次规整,做一般工业胶、密封剂,性价比很实在。
SEBS副牌做胶,这三个坑别踩
头一条,苯乙烯含量和粘度要对号。做胶先定初粘、持粘需求,再选对应苯乙烯含量和粘度的副牌,别拿“差不多”的牌号硬凑。
再一条,耐候要求高的别硬上副牌。户外胶、需耐UV的密封,加氢牌号的耐候是配方本事,副牌单项超标先掉耐候。
还有一条,认准原厂大包装。SEBS颗粒容易吸潮、掺假,来路不明的“副牌”可能掺了SBS,做出来的胶夏天软、冬天脆。批次留样,小试一炉胶再放量。
科隆仓库现货|SEBS送货
主推品牌:科腾、旭化成、台橡
主要牌号:Kraton G系列、Tuftec系列、Taipol系列
包装规格:大包装/小包装均有备货
仓库现货通常在4000吨上下
小包副牌备货600-900吨、箱装副牌备货250-450吨、大包料/吨包料备货2650-3150吨
供应保障:检测单随货
六条口诀,胶厂对号下单
1. 户外耐候、需耐UV——走正牌或高等级
2. 室内胶、普通密封剂——原厂副牌可以上
3. 先定初粘持粘需求——再选苯乙烯含量与粘度
4. 进厂小试一炉胶——初粘、持粘实测
5. 认准原厂大包装/小包装,防掺SBS
6. 批次留样,出问题能对上号
石家庄有家做建筑密封胶的客户,之前为压成本进过一批掺了SBS的“SEBS副牌”,结果夏天胶软得往下流、冬天一掰就裂,工地验收整批退回,一年赔进去小几十万。后来换成科腾和台橡的原厂副牌,进厂先小试测初粘持粘,再按炉放量,冬夏两季的胶性都稳了,退货率从12%压到0.8%以内,单吨胶成本还降了一截。
做热熔胶的、做密封剂的、做TPE改性的,谁没被SEBS坑过?
是胶一撕就分层、客户整批退回?还是冬天脆裂、夏天流淌?或者买着买着买到掺SBS的料,胶性忽高忽低?
Anyone who makes hot melt adhesive knows that if the SEBS grade is chosen incorrectly, the glue will delaminate as soon as it is peeled — not saving a ton of material, and the customer's return order arrives first.
SEBS is the product of hydrogenating SBS. It is weather-resistant, heat-resistant, and does not yellow. It is essential for making hot-melt pressure-sensitive adhesives, sealants, and modified TPE. However, the genuine product is not cheap; when a container of material is purchased, the profit margin for adhesive factories becomes considerably thinner.
The problem is that SEBS sub-brands are trickier: whether they are linear or star-shaped, how high the styrene content is, whether the oil is fully blended — even a slight difference can change the initial tack, holding tack, and temperature resistance of the rubber. To put it bluntly, it's not that SEBS sub-brands can't be used, it's that you haven't fully understood the characteristics of their grades.
This article explains SEBS thoroughly: how it really differs from SBS, which are the top three companies in the world, and how to choose secondary brands for making glue and sealants.
Hydrogenate SBS, and the adhesive will be weather-resistant and non-yellowing
SEBS is a styrene-ethylene-butylene-styrene block copolymer, which essentially means hydrogenating the double bonds in the middle of SBS. After hydrogenation, it improves UV resistance, heat resistance, and anti-yellowing performance, can be used without vulcanization, and is also easy to recycle. It is relied on for making hot melt adhesives, sealants, plastic modification for toughening, and soft-touch TPE.
In the adhesive industry, it is often said: for weather resistance, temperature resistance, and no yellowing, choose SEBS; if you want cheap and only for short-term indoor use, then use SBS.
The global SEBS landscape is top-heavy: U.S. company Kraton consistently leads, with its Kraton G series being the benchmark in the SBC industry; Japan's Asahi Kasei's Tuftec® is the main choice for transparent and medical-grade applications; Taiwan's TSRC's Taipol® moves large volumes in adhesives and modification. Japan's Kuraray Septon® is in the second tier. All three are outside mainland China.
The secondary batch is the same hydrogenated polymer, it's just that a certain value on the lab report is fluctuating.
SEBS sub-brand refers to batches from the same factory and same grade, where the styrene content, Mooney viscosity, or flow index slightly deviates in the factory inspection. The molecular structure after hydrogenation is consistent with the main brand, and it is still the original factory's native rubber pellets.
Four sources remain unchanged: material left at the beginning and end of parking, transition material during grade switching, batches exceeding individual standards due to process fluctuations, and leftover material from secondary lines.
Boundaries must be clear: the main brand fully meets all standards; the secondary brand has minor fluctuations in individual items; reprocessed material is made from leftover rubber particles mixed and granulated, having already undergone thermal history, with discounted performance; recycled material fluctuates greatly. When making rubber with SEBS, beware of variations in styrene content and viscosity—these two directly determine initial tack and holding tack, and if they fluctuate, the rubber will delaminate.
Sub-brand key phrase: SEBS sub-brand purchased the wrong grade, the hot melt adhesive produced became brittle in winter and fell apart when torn, causing an entire batch of sealant to be scrapped on the spot.
Kraton: Kraton G, a benchmark in the SBC industry
Kraton is the big brother of styrene block copolymers. The Kraton G series has very fine grade distinctions, allowing you to match it for adhesives or modifications. Its subsidiary grades are mostly batches with slight deviations in viscosity or styrene content, but the base material is consistent.
For making ordinary sealants and adhesives that do not require weather resistance, choosing its selected secondary brand can reduce the cost by one yuan.
Asahi Kasei: Tuftec®, the mainstay of transparent and medical-grade products
Asahi Kasei's Tuftec® has a strong reputation for high transparency and medical-grade SEBS, and is widely used for transparent TPE and high-demand adhesives. Its sub-brand controls color and transparency finely, making it reliable for adhesives and modified parts that do not require high transparency.
Taiwan Rubber: Taipol®, the volume leader in the adhesive market
Taiwan Rubber is a major SBC supplier in Taiwan. Taipol® SEBS has a large volume in hot melt adhesives, asphalt modification, and plastic toughening, with stable supply. Its secondary brand has uniform batches, suitable for general industrial adhesives and sealants, with a very reasonable cost-performance ratio.
SEBS sub-brand in rubber making, avoid these three pitfalls
First point, the styrene content and viscosity must match. When making adhesive, first determine the initial tack and holding tack requirements, then select the corresponding grade with the appropriate styrene content and viscosity. Don't forcefully use a 'similar' grade.
One more thing, don’t force secondary brands if high weather resistance is required. For outdoor adhesives and seals that need UV resistance, the weather resistance of a hydrogenated grade depends on the formulation itself; if a secondary brand exceeds an individual standard, it will first fail in weather resistance.
There's one more thing: make sure to choose the original manufacturer's large packaging. SEBS granules easily absorb moisture and can be adulterated, and unknown 'secondary brands' may contain SBS, resulting in rubber that is soft in summer and brittle in winter. Keep samples from each batch and test a small amount before scaling up.
Cologne Warehouse Stock | SEBS Delivery
Main promoted brands: Coteng, Asahi Kasei, Taiwan Rubber
Main grades: Kraton G series, Tuftec series, Taipol series
Packaging specifications: Both large and small packages are available in stock
The warehouse spot goods are usually around 4,000 tons.
Small package secondary brand stock 600-900 tons, box-packed secondary brand stock 250-450 tons, large package material/ton package material stock 2650-3150 tons
Supply Assurance: Test Report Accompanies Goods
Six formulas, the glue factory places orders according to the numbers
1. Outdoor weather-resistant, needs UV resistance — go for a reputable brand or high grade
2. Indoor adhesives, general sealants – original brand's secondary line can be used
3. First determine the initial tack and holding tack requirements — then choose the styrene content and viscosity
4. Pilot test of one batch of glue in the factory — initial tack and holding tack measurement
5. Make sure to choose the original factory large/small packaging to prevent adulteration with SBS.
6. Retain samples from each batch so that any problems can be traced.
There is a client in Shijiazhuang that produces construction sealant. Previously, to reduce costs, they purchased a batch of 'SEBS secondary brand' mixed with SBS. As a result, in summer the sealant was so soft that it flowed down, and in winter it cracked as soon as it was bent. When inspected at the construction site, the entire batch was returned, resulting in a loss of nearly several hundred thousand yuan over the year. Later, they switched to original secondary brands from Ketten and Taiwan Rubber. The factory first conducted small-scale tests to measure initial adhesion and cohesive strength, then increased the quantity according to batch production. The properties of the sealant remained stable in both winter and summer, the return rate dropped from 12% to less than 0.8%, and the cost per ton of sealant also decreased.
Those who make hot melt adhesives, sealants, or TPE-modified products—who hasn't been screwed over by SEBS?
Does the glue separate into layers as soon as you peel it off, causing the entire batch to be returned by customers? Or does it crack in winter and flow in summer? Or do you end up buying material mixed with SBS, with the stickiness sometimes high and sometimes low?