German Technical Background VOK-S 740 Styrene Volatilization Inhibitors Used in Unsaturated Polyester Resins Replaces BYK-S 740

German technical backgroundVOK®-S 740 styrene monomer volatilization inhibitor for unsaturated polyester resin

VOK®-S 740 Styrene volatilization inhibitor for unsaturated polyester resins. Reduces the volatilization of styrene monomer in phthalate resin, up to 90%. Does not affect the interlayer adhesion of laminated polyester resin. 

Product Information 

Chemical composition of paraffin-containing hydroxyl polyester solution 

Typical materialized data 

The data presented on this data page are typical values only and are not technical indicators of the product. 

Acid value:<7 mg KOH/g 

Density (40 °C): 0.86 g/ml 

Refractive index (40 °C): 1.456 

Flash point: 66 °C 

Purchase form: paste 

Storage and transportation 

Delamination or turbidity may occur during storage and transportation. Disperse evenly before use. 

Application areas 

Room-temperature curing resin system 

Product features and benefits

VOK®-S 740 is a highly effective additive for reducing styrene monomer volatilization in phthalate resins for use in mold opening processes. The use of this product does not affect interlayer adhesion. Recommended Use: VOK®-S 740 is particularly recommended for phthalate resins and can also be used in isophthalic acid resins.

Recommended dosage 

0.5-1% additive dosage (purchased form) is based on total formulation. 

The above recommended addition amount is for reference, and the suitable addition amount needs to be determined by a series of tests.

Incorporation method and processing guidance 

Under continuous agitation, VOK®-S 740 should be added to the resin before other formulation components are added. For easier addition, it is recommended to melt the product (not to exceed 40°C) and stir liquid VOK®-S 740 into the resin. If it does not melt, add 5-20% styrene monomer to make an ointment, and then dissolve into the resin. The storage time of VOK®-S 740 and styrene monomer mixture should not exceed 24h, and the dispersion is uniform before processing. 

Special considerations 

In non-thixotropic resins, VOK®-S 740 has a tendency to flocculate during storage and precipitate on the resin surface. In the case of delamination, the resin must be stirred before processing. Among non-thixotropic resins, VOK®-S 740 can be used with 0.2-0.5 % VOK®-LP W 6236 for good storage stability.