Contributes to product weight reduction and high precision
Modified PPE Resin

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What is the XYRON™ TF Series ?

XYRON™ modified PPE resins boast a number of advantages derived from PPE—including heat resistance, low specific gravity, and flame retardance—that have made them the right choice for many vehicle-mounted batteries and peripheral components. However, resins used for battery applications must not only offer low specific gravity and flame retardance, but must also be resistant to various types of oils—a requirement that demands improvements over existing materials based on PPE, a non-crystalline resin. 

In response to this demand, Asahi Kasei has combined our proprietary compatibilizer and flame-retardance technologies to develop a new solution: the XYRON™ TF series of PP-alloy grades. These are non-halogen flame-retardant materials that deliver high-level flame retardance (UL94 V-0, 1.5mm thickness) while simultaneously achieving oil resistance thanks to alloying with PP (polypropylene), a crystalline resin. 

Battery components

Key features of the XYRON™ TF series

Excellent mechanical and electrical properties with flame retardance

XYRON™ TF701 is an oil-resistant flame-retardant PP+PPE alloy grade that exhibits flame retardance on par with that of flame-retardant PS+PPE grades together with good mechanical properties, low specific gravity, and excellent electrical properties.

Basic properties of XYRON™ TF701
Basic properties of XYRON™ TF701

Oil resistance 

To characterize oil resistance, we measure critical strain. We mount a test fragment on a bending bar designed to ensure continuously varying strain (Figure 1), coat this fragment with various oils, and measure the minimal strain at which the fragment ruptures (the critical strain).
Table 3 compares the critical strains measured for  XYRON™ TF701 and for an existing flame-retardant PS/PPE resin grade coated by three types of oil: engine oil, brake fluid, and lubricating oil. For all three oils, the critical strain measured for TF701 is significantly higher than that for the existing flame-retardant PS/PPE resin, making TF701 the right choice of material for components that may come into contact with these oils.

ザイロン™ TFシリーズ ベンディングバー
Bending bar
Critical-strain values for XYRON™ TF701
Critical-strain values for XYRON™ TF701

Good moldability

To characterize formability and ease of processing for injection molding, we conducted fluidity tests using a spiral-flow mold, and the results are shown below. At a mold temperature of 80°C and a maximum injection pressure of 50 MPa, tests at various cylinder temperatures confirmed that the fluidity of TF701 is superior to that of an existing flame-retardant PS+PPE resin. One likely application for this material will be to fabricate cell spacers for vehicle-mounted batteries; we confirmed the successful use of TF701 to form a thin-walled component mimicking such a spacer (dimensions: 100 mm × 100 mm × 0.4 mm thickness) via standard injection molding. In general, given the limited space available to house vehicle-mounted batteries, the ability to form thinner spacers is advantageous from a space-reduction perspective.

ザイロン™ TF701 スパイラルフロー金型を用いた流動性(厚み:2mm)
Results of fluidity tests using a spiral-flow mold (thickness: 2mm)

Another key imperative is to minimize warping when forming components, as materials susceptible to significant warping may yield components that cause interference problems in product assembly. The following figure quantifies the extent of warping observed in the formation of a slab of dimensions 150 mm × 150 mm × 2 mm thickness. We see that, in comparison to an existing flame-retardant PP material, TF701 exhibits significantly less warping and is thus superior for component formation.

ザイロン™ TF701 150*150*2mm 平板射出成形時の低反り性
Warping of a 150 mm × 150 mm × 2 mm slab formed by injection molding

Heat resistance: resistance to thermal aging, and robustness in warm, humid environments 

To characterize resistance to thermal aging (in an 80°C environment), we measured Charpy impact strength retention, and the results are shown in Figure 3. TF701 retains more than 80% of its strength after 3,500 hours, demonstrating the suitability of this material for applications requiring long-term retention of physical properties in high-temperature environments. 
We also measured the retention of Charpy impact strength to characterize aging properties in a warm, humid environment (85°C with 85% relative humidity). As shown in Figure 4, here again, TF701 exhibits high retention of physical properties, indicating excellent robustness in warm, humid environments. 

ザイロン™ TF701 80℃環境下での耐熱エージング性
Resistance to thermal aging in 80°C environment
ザイロン™ TF701 85℃ *85RH% 環境下での耐湿熱性
Robustness in a warm, humid environment (85°C, 85% relative humidity)

Resistance to copper contamination

PP and other olefin-based resins are known to exhibit poor resistance to copper contamination: in environments involving contact with copper or other metals, these materials suffer oxidation reactions that degrade their physical properties. To characterize resistance to copper contamination, we measured retention of tensile strength for test fragments of materials wrapped in copper foil and aged at 150°C. The results are shown in Figure 5. Whereas the tensile strength of an existing flame-retardant PP material begins to decline rapidly after 500 hours, TF701 retains more than 80% of its tensile strength after 1000 hours. This demonstrates the ability of TF701 to retain stable material properties over long periods of time in environments involving contact with copper or other metals. 
The copper-contamination resistance of TF701—in addition to its low specific gravity, tracking resistance, and flame retardance—makes this material an ideal choice for many types of components, such as busbar covers for vehicle-mounted battery systems (components that prevent electric shocks and short circuits for busbars made from copper or other metals). 

ザイロン™ TF701 150℃環境下での耐銅害性
Resistance to copper contamination in a 150°C environment

Application Cases

Inter-cell spacer


An insulating component that separates the cells of an EV battery.
Thin walls, light weight, flame resistance, etc. are required.

Related articles


TF701, 340Z


  • Flame resistance (V-0, non-halogen)
  • Acid / alkali resistance
  • Thin-wall moldability
  • Oil and chemical resistance (TF701)

Bus bar cover


An insulated protective cover for the conductor through which high voltage and large current of an EV battery flows.
In addition to requiring electrical tracking ability, flame resistance and heat resistance are also required.

Related articles



440Z, 443Z



  • High strength
  • Long-term heat resistance (RTI Elec. 130°C)
  • Flame resistance (V-0, non-halogen)
  • Tracking resistance (CTI PLC 0, 600V)


  • Dimensional stability 
  • Low specific gravity (weight reduction through reduced material usage)
  • Flame resistance (V-0, non-halogen)
  • Tracking resistance

Related Contents

Product Data/Tips for Use *Handling Precautions

Precautions when handling XYRON™ (modified polyphenylene ether resin)

The content of this document is based on currently available materials, information and data, and may be revised based on new findings. In addition, since the precautions are intended for normal handling, in the case of special handling, please use after implementing safety measures suitable for the application and usage.

1. Handling Precautions

The following are important points for handling XYRON™. Please use it for safe handling of XYRON™. A separate safety data sheet has been created for handling precautions for each grade of XYRON™. Please read the safety data sheet before use. Please investigate the safety of the additives your company uses other than XYRON™.

A. Notes on work
When working with XYRON™, be careful to avoid contact with or inhalation of pellets, molten resin, and gases generated during melting. In the unlikely event of contact or inhalation, first aid measures are listed below.

  • ・If it gets into your eyes
    If it gets in your eyes, rubbing it may cause irritation or damage the cornea, so wash thoroughly with clean water for at least 15 minutes without rubbing, and if there are any abnormalities, seek medical attention.
  • ・If it adheres to the skin
    In general, wash with water or soap, and if molten material adheres, immediately cool with clean water. Do not forcibly peel off the hardened resin on the skin, and seek medical attention.
  • ・If inhaled
    Normally, there is no direct effect on the human body, but if you inhale dust, etc., gargle well with clean water. If breathing fumes from the melt makes you sick, move to fresh air and wait for recovery. If it does not recover, get medical attention.
  • ・If swallowed
    Spit it out as much as possible, and if there are any abnormalities, seek medical attention.

B. Safety and health precautions
Please be careful to avoid contact with eyes or skin or inhalation of the gas generated when XYRON™ dries or melts. Also, avoid touching the hot resin directly. During drying and melting operations, it is necessary to install a local exhaust system and wear protective equipment (safety glasses, protective gloves, etc.).

  • ・Equipment measures
    In the molding work, there is a risk that gas may be generated by heating and melting, so please install an effective local exhaust system etc.
  • ・Respiratory protective equipment
    Wear a mask for organic gas when working in a place where there is a possibility of inhaling generated gas or fume. Wear a dust mask when working with resin products, sanding, or other work that generates dust.
  • ・Protective glasses
    When working, wear resin safety glasses with side seals, resin goggles, etc.
  • ・Protective gloves
    Wear as needed. In particular, when handling molten resin, use gloves with good heat insulation to prevent burns.
  • ・Protective clothing
    Regular work clothes are fine, but especially when handling molten resin, wear long-sleeved clothing to prevent burns.
  • C. Precautions regarding combustion
    XYRON™ is flammable and should be handled, transported, and stored away from heat and ignition sources. In the event of a fire, strong heat, black smoke, carbon dioxide gas, carbon monoxide gas, and other toxic gases may be generated. To extinguish the fire, you can use the same extinguishing agents as for general fires, such as water, fire extinguishing foam, and powder extinguishing agent. Wear fire retardant clothing and breathing equipment when extinguishing a fire.

    D. Precautions for transportation
    Avoid getting wet and rough handling to prevent the packing bag from tearing. In the unlikely event that the bag is broken and the pellets are scattered, take special care not to slip and fall, and quickly sweep up and collect or dispose of them. Take measures to prevent static electricity disasters during pneumatic transportation.

    E. Precautions for storage
    Please store XYRON™ away from direct sunlight and places with high temperature and humidity. Store it away from heat and ignition sources, and take measures to prevent static electricity hazards.

    F. Disposal precautions
    XYRON™ can be disposed of by landfill or incineration. When disposing of waste in a landfill, please entrust the disposal to a certified industrial waste disposal company or a local government if that organization is doing so, in accordance with the "Waste Disposal and Public Cleansing Act." When incinerating, please use incineration equipment and process in accordance with various laws and regulations such as the Air Pollution Control Act.

    2.Regarding conforming standards

    There are grades XYRON™ that comply with the self-regulatory standards for food containers and packaging made of polyolefin and other synthetic resins, Ministry of Health and Welfare Notification No. 370, UL, CSA, and Electricity Control Law. Please contact our office for details.


    Please be aware of industrial property rights when using this product.

    The data in the catalog are representative values obtained based on the specified test methods and are not guaranteed values. Please refer to them as a guide to select optimal suitable grade for your individual application. Please note that these values may be changed in order to improve the physical properties.

Please contact us to ask any questions, discuss any concerns, and request samples.

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