Development and production of epoxy resin

In 2004, we started contract manufacturing of epoxy resin used for carbon fiber composite material (CFRP) for Boeing 787.
Taking advantage of the synthetic technology accumulated over the years with this production, we have begun to develop a wide range of epoxy resins such as electronic materials and adhesives.

About the product

We are developing highly heat-resistant epoxy resins using compounds possessing our own diphenylsulfone skeleton.
First, we succeeded in the scale-up trial of 3,3'-diaminodiphenylsulfone epoxy resin (TG3DAS) as the first step, and started sample work.


Registry No.78542-64-0
New chemical substances

TG3DAS Tetraglycidyl - 3,3' - diamino diphenyl sulfone

Basic physical properties

  Test value
appearanceYellow transparent flakes
Volatile matter0.2% or less
Epoxy equivalent136±6 g/eq.
Hydrolyzable CI1000ppm or less

Cured physical properties

  TG3DAS TGDDM Remarks
Cured product appearance TG3DAS TGDDM  
Glass transition temperature(℃) 250 260 TMA 2nd RUN
Average coefficient of linear expansion(ppm/℃)
< Tg
> Tg
Bending strength(MPa) 100 160  
Flexural modulus(GPa) 4.3 3.2  
Hardness(Shore D) 92 90  
Curing conditions Mixing ratio TG3DAS:DDS=100:40(Parts by weight) 120℃×1hr+150℃×2hr+180℃×3hr Mixing ratio TGDDM:DDS=100:45(Parts by weight) 120℃×1hr+150℃×2hr+180℃×3hr  
※TGDDM=Tetraglycidyl 4,4'diaminodiphenylmethane

What’s Benzoxazine?

Oxazine resin formed by thermal ring-opening polymerization of oxazine compounds is a new thermosetting resin that has excellent flame retardancy, dimensional stability, low water absorption, low dielectric constant and heat resistance, and does not generate by-product gas during molding. It is attracting attention.
We have succeeded in scaling up DHDPM (dihydroxydiphenylmethane) type benzoxazine, and are implementing sample work.
We are also developing a DHDPS (dihydroxydiphenylsulfone) type benzoxazine that can be cured at a lower temperature with higher heat resistance. In addition, various structural designs are possible by combining various phenols and amines, and we propose benzoxazine compounds according to customer requirements.

Heat causes the oxazine ring to open, producing a phenolic hydroxyl group and polymerizing. Heat causes the oxazine ring to open, producing a phenolic hydroxyl group and polymerizing.


  • Dimensional stability
  • Heat-resistant
  • Flame retardance
  • Electrical insulation

An excellent cured product can be obtained!

[Application example]
adhesive Printed board Matrix resin etc.

Structural formula of benzoxazine

Structural formula of benzoxazine * This is a representative skeleton and the product is a mixture.

BF-BXZ Stage:Pilot
X= CH2
Typical quality Adhesive solvent ≦ 2%
Aniline≦ 2%

BS-BXZ Stage:Laboratory
X= SO2
Typical quality Adhesive solvent ≦ 2%
Aniline≦ 2%

Solubility of benzoxazine

Solvent type BS-BXZ BF-BXZ
Halogenated hydrocarbonChloroform
Ether typePropylene glycol monomethyl ether acetate
EsterEthyl acetate
Aprotic polar solvent systemN, N-dimethylformamide
Ketone systemMethyl isobutyl ketone
Aromatic hydrocarbontoluene×
Aliphatic hydrocarbonHexane××
Method:Add 2ml of solvent to 0.5g of BXZ and confirm solubility at room temperature. Those that dissolve are marked with ○, and those that are insoluble are marked with ×.
Exothermic behavior during curing(BF-BXZ)

Exothermic behavior during curing(BF-BXZ)

Exothermic behavior during curing(BS-BXZ)

Thermogravimetric analysis(BS-BXZ)

Thermogravimetric analysis(TGA)

5% weight loss temperature(Td5)367℃337℃
Residual charcoal rate(550℃)76%54%

Measurement condition

Used equipmentTG/DTA6200
Measurement temperature30~300℃
Heating rate10℃/min
flowflow 150ml/min
After 1stRUN under this condition, naturally cool down, change the measurement temperature to 30 ~ 600℃, perform 2ndRUN, read the weight loss-5% temperature and the remaining 550℃.

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