Cyclic Carbodiimide Compound

New Hydrolysis-resistant Agent Generating No Toxic Isocyanate Gas

Teijin's cyclic carbodiimide compound


The durability of resin changes according to various conditions such as temperature, UV rays, and oxygen. In particular, it is significantly affected by the hydrolysis caused by humidity, rain, and dew condensation. This has been a challenge faced by resin, and carbodiimide compounds are used in general to enhance the hydrolysis-resistant property of polyester and other resins.

However, these carbodiimide compounds are known to generate toxic isocyanate gas when they react with resin. It has been reported that the exposure to a very low concentration of the isocyanate gas stimulates the skin, the eye, or the airway, and the exposure limit in the working environment at manufacture settings is established.

Against this backdrop, Teijin has used the cyclic carbodiimide compound with an aim to render hydrolysis-resistant property to our highly heat-resistant bioplastic BIOFRONT. As its similar effects on other many resins have been confirmed, we will launch the agent in the market.

Highly Safe Cyclic Carbodiimide Compound Generating No Isocyanate Gas.

 Comparative data of isocyanate gas generated at the time of adding to polylactic acid


Since the new hydrolysis-resistant agent developed by Teijin is a carbodiimide compound having cyclic structure, it generates no toxic isocyanate gas when it reacts with resin. Therefore, it can be manufactured and used safely in any working environment in manufacturing settings.

This cyclic carbodiimide compound also complies with the Act on the Evaluation of Chemical Substances and Regulation of Their Manufacture, etc. and the Industrial Safety and Health Act in Japan and REACH in Europe. It is in the process of complying with TSCA in the USA and the Act on the Evaluation of Chemical Substances in China.


Applicable to Various General-purpose Resins, Giving High Hydrolysis-resistant Properties with a Small Amount

As with the conventional carbodiimide compound, this cyclic carbodiimide compound can be applied to a broad range of general-purpose resins, including polyesters, polyamides, polyurethane, and polylactic acid, without adversely affecting the performance of these resins. A smaller amount of this cyclic carbodiimide can render higher hydrolysis-resisitant properties than the conventional products.

Hydrolysis of PLLA

Hydrolysis of PBT

Comparative data of hydrolysis properties at the time of adding to polylactic acid (left) and polybutylene terephthalate resin


Millable urethane elastomer
(including carbon black, cross-linking agent, etc.)

Millable urethane elastomer
(including carbon black, cross-linking agent, etc.)
+  Cyclic carbodiimide compound

Millable urethane elastomer
(including carbon black, cross-linking agent, etc.)
+ Conventional carbodiimide

Cross-linking property after vulcanization (at 155°C , tc (90) + 10 min)
Hardness Hs(JIS-A) 81 81 79
Intermediate tensile stress(MPa) M100 7.3 7.3 6.4
M200 20.6 20.9 18.7
M300 29.6 30.2 28
Breaking stress TB(MPa) 30.8 31.2 30
Bleed (Air, rt, after 336 hours) Absence Absence Presence
Cross-linking properties after hot water test (after 336 hours of hot water test at 80°C )

Hardness  Hs (JIS-A)
(An amount of change)

Intermediate tensile stress竊뉾Pa竊?/th> M100
(Rate of change (%))
(Rate of change (%))
(Rate of change (%))
Breaking stress TB(MPa)
(Rate of change (%))

Comparative data of the performance of polyurethane resin to which the same amount is added

Use of Cyclic Carbodiimide Compound in Broader Applications

With the heat-resistance to higher than 300 degree C rendered by its unique molecular design, the agent can be mixed with resins at highest-ever temperature around 300 degree C.  This hydrolysis-resistant agent has a wide array of applications, including the use as a cross-linking agent to harden or adjust the viscosity of paint and coating agents.

Tm (°C) 1% weight reduction temperature (°C) 5% weight reduction temperature (°C)
230 365 397

Thermophysical property of cyclic carbodiimide compound

Inquiry about cyclic carbodiimide compound