全球每三支新冠抗原检测卡的透明外壳,就有一支藏着这种塑料的副牌

产品中心 发布时间: 2026-09-15 3773 阅读

Let's start with a number.

In the 2024 global medical diagnostic consumables market, the factories making antigen detection cards, ELISA microplates, and pre-filled syringe piston rods all rely on a type of transparent plastic. It's not called PC, not PMMA, nor PS, but it's called COC, a cycloolefin copolymer.

The total global production capacity for this thing is only 80,000 to 90,000 tons per year. It doesn't sound like much, but it combines transparency, low precipitation, sterilization resistance, and biocompatibility. If PC and PMMA want to be medical-grade, they have to make way for it.

Here's the problem: genuine COC sells for over 200,000 yuan per ton, and small manufacturers don't dare touch it; Many of the "cheap COCs" circulating on the market are made from recycled materials; if the precipitated material exceeds the standard, the entire batch of diagnostic cards goes straight into hazardous waste.

Genuine products are expensive, recycled materials are risky—where is the middle path? The answer is sub-brands from major manufacturers. Today's article explains the global landscape of COC, the three leading manufacturers, and whether sub-brands can actually be used, all at once. What kind of material is

COC, and why is the medical community rushing to use it?

To put it plainly, COC is a transparent engineering plastic formed by copolymerizing ethylene and cyclic monomers (like bornoleene) into the same polymer system.

It has three hidden abilities. First, its transmittance is on par with PMMA, but its birefringence is low, so it doesn't fade in optical and diagnostic devices. Second, it's resistant to gamma rays and ethylene oxide. PC turns yellow after a single gamma test, but COC doesn't. Third, the precipitates are extremely low, making it a consumable for in vitro diagnostics and won't mix with reagents.

So the transparent covers for antigen test cards, PCR octa-tube tubes, and pre-filled syringes are increasingly made with COC.

But it's expensive. It's not because of cutting corners, but because there are factories that can make these products on one hand in the world.

The global COC companies are basically these three major foreign companies .

is ranked by capacity, and global COC/capacity is monopolized by a few Japanese and German companies, with CR3 accounting for over 90%. The following three companies are the main suppliers you can't avoid.

First, TOPAS Advanced Polymers. The origin of this factory needs to be clarified: it was originally a team from Ticona, a subsidiary of Celanese, working on COC in Germany, under the brand TOPAS. Around 2020, Japan's Polyplastics brought this COC business under its umbrella. Now, TOPAS Advanced Polymers GmbH is a wholly-owned subsidiary of TOPAS Plastics, with its production base in Germany. Its COC capacity is about 35,000 tons per year, accounting for about 40% of the global market, and it is recognized as the global leader in COC routes. In medical prefilled syringes and diagnostic consumables, TOPAS is widely recognized.

The second company, Mitsui Chemicals. Japan's Mitsui Chemicals takes a different copolymerization route, with a brand called APEL. The APEL series is characterized by a wide variety of grades, ranging from low heat resistance to high heat resistance, with corresponding grades for lenses and medical packaging. Mitsui accounts for about 7% to 10% of the COC/COC family's capacity. Not a large but full range, and high-end optics and medical devices are often mentioned.

The third company, JSR (Japan Synthetic Rubber). JSR originally made synthetic rubber and photoresist, and its COC/COP material made using the open-loop polymerization route is called Arton. Arton is characterized by transparency, heat resistance, and chemical resistance, and is skilled in making optical films and precision medical devices. Its production capacity is not large, about 5,000 tons per year, but it is highly recognizable in high-end film materials and microstructural components.

Zeon's Zeonex/Zeonor set is, strictly speaking, an open-loop polymerization followed by hydrogenation via the COP route. It is closely related to COC but not on the same process; the article will focus on COP in detail later.

Subbrand, let's break down the concept first

When many people hear "subbrand," they think of defective products, scraps, recycled and re-pelletized materials. This is a big misunderstanding.

The precise definition of a secondary brand is: in polymerized products from the same manufacturer and grade, some technical indicators during factory inspection do not fully match the lower edge of the genuine brand. It's not another batch of material, but the part of the same batch that has been tested for a breath of the same quality.

Where does it come from? There are just four gaps. First, the tail material at the end of the unit when it starts and stops; the polymerization reaction should be stable at the start and close when it is about to end, so the material indicators at both ends are floating. Second, the transition material at grade switching, where the previous grade has just been cut, and remnants from the previous grade remain in the barrel. Third, the batches in normal production where certain indicators such as melting finger, hue, light transmission, and ash content have slight shifts. Fourth, the tail material from the secondary line.

Key properties: They are still original original polymer particles, with molecular structure identical to genuine ones, only minor fluctuations in some indicators. They are not pelletized from waste plastic and have not experienced a second heat cycle.

Boundaries must be clear: genuine brands meet all indicators and have stable batches; secondary brands have slight deviations in certain indicators and coexisting base materials; recycled or sprue material is recycled scraps from the product and have already experienced one heat history; recycled materials are recycled waste plastics with large performance fluctuations. These four are completely different in price and usage.

TOPAS secondary brands are suitable for what kind of

TOPAS secondary brands mainly float on two indicators: first, light transmittance is slightly lower than the genuine brand; second, the hue and yellowness index slightly fluctuate.

This kind of secondary brand can't be used for optical lenses requiring high transmittance, but it's more than enough for the transparent cover plate of antigen test cards, the frame of ELISA plates, and non-critical components of reagent tubes. Think carefully — these items need to be "visible, non-precipitated, sterilizable," not to compare resolution with lenses.

TOPAS secondary brands mostly come in large packages, entering the silos of modification and product factories. When poured out, they are almost indistinguishable from the genuine brand, only the secondary label on the original packaging.

Mitsui APEL secondary brand, how to choose

Mitsui APEL secondary brand, characterized by multiple grades and a bit of fluttering and variation. Some grades have slightly floating melt fingers, while others withstand temperatures about 35 degrees lower.

When choosing APEL secondary brands, first look at which indicators your parts are sensitive to. For injection-molded thin-walled parts, check if the melt fingers match the mold flow; For parts requiring temperature resistance, check where the lower edge of the thermal deformation temperature lies. The advantage of APEL secondary brands is that their molecular chains share the same origin as the genuine brand, so you don't need to change the formula after switching, just test the sensitive indicators once more.

JSR Arton's secondary brand is small in quantity but refined

Arton Its production capacity is small, and its outflow is even more limited, so it's not widely available on the market. Its secondary brand is mostly used for internal coatings of optical films and non-critical layers of micro flow control components. When encountering Arton secondary brands, first ask which brand it is, whether it's light-transmitting or heat-resistant, and don't use it to target high-end lenses.

Secondary brand buying pitfalls: Don't skimp on these three things

First, recognize the brand, not the "brand." For the same factory, sub-brands of different grades cannot be mixed; you want the grade corresponding to the original formula.

Second, inspect the indicators before signing. COC especially requires attention on light transmittance, yellowness, and precipitates. These three must be sampled before entering the factory, not just the seller's verbal guarantees.

Third, packaging comes in different sizes. COC sub-brands come in both large and small packages on the market. Small packages are suitable for sampling and small batch trial production, while large packages are suitable for mass production to dilute costs. Don't compare small packaging materials by the price of large packages, and don't do the opposite.

Cologne Warehouse In Stock | COC Temperature and Humidity

Main Brands: TOPAS Advanced Polymers (under Baoli), Mitsui Chemicals Japan, JSR

Main Grades: TOPAS, APEL, Arton

Packaging Specifications: Original factory packaging, available in large and small packaging; Small sub-brand, boxed sub-brand, large package/ton material sorted and stacked, stocked by batch

warehouse stock: COC sub-brand warehouse stock about 5000 tons

spot details: small sub-brand stock 800-1000 tons, containerized sub-brand stock 300-500 tons, large package/ton material stocking 3500-3900 tons

Supply guarantee: test before signing, test key indicators before entering the factory, then sign a contract

selection formula and a real case

Ultimately, COC sub-brand is the same production line for genuine brands—the same set of metallocene catalytic polymerization devices is only slightly different from the light transmittance report card.

When selecting COC secondary brands, remember these five points: first, check if the application is sensitive; second, check which brand and brand correspond; third, check the three items for light transmission and yellowness; fourth, select large or small packages by batch; fifth, keep batch samples for traceability.

Let me share a case. There is a factory in Anshan that makes in vitro diagnostic consumables. Previously, they made transparent covers for antigen test cards but always used genuine TOPAS, costing over 200,000 yuan per ton, which cost couldn't be lowered. After replacing a batch of domestic transparent material, it was returned due to excessive precipitates. Later, we paired it with a sub-brand of the same TOPAS grade, with light transmittance differing by a few fractions and yellowness within controllable range. The precipitates and sterilization adaptability were consistent with the genuine brand. After switching to the sub-brand, the cost per material dropped significantly, and the cover plate passed customer acceptance on the first try, with a yield rate stable above 95%.

This is the value of the sub-brand—not buying cheaply, but about "same-origin, sufficient, traceable." Ningbo Kelong New Materials Co., Ltd. has been doing imported sub-brands for many years. For niche high-transparency materials like COC and COP, similar cases are handled every year. Basically, it's to help you lock in light transmission and precipitation before mass production.

Who in medical consumables, optical components, or diagnostic cards hasn't been driven down by COC's high prices? Is it that genuine brands don't dare to pay over 200,000 per ton? Or are they trying to buy cheaper but have excessively precipitated material after entering the product? Or do they find the grade is wrong and get confused when using the secondary brand?

Data and Data Sources

China Chemical Information Weekly "COC/COP Domestic Substitution Strengthens, Market Space Expands" (2025-12)

TOPAS Advanced Polymers Official Announcement and Polyplastics Production Capacity Disclosure

Shanghai Securities News · Wuxi Acoli 2024 Annual Report Summary (COC/COP Competitive Landscape)

Dataintelo "Cyclic Olefin Copolymer Market" Market Research Report (2026)

Original Document "Development Opportunities in the Plastics Industry under the Background of New Quality Productive Forces" (COC/COP Capacity Table)

Data

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