PURPOSE: To obtain the subject antifogging agent having low bleeding tendency and excellent heat-resistance, transparency and antifogging property and useful for packaging film, etc., by using a polyglycerol fatty acid ester containing oleic acid, lauric acid and a specific amount of diester.
CONSTITUTION: This antifogging agent for a styrene resin film is a polyglycerol fatty acid ester produced by the dehydration reaction of oleic acid, lauric acid, capric acid, stearic acid and a polyglycerol (e.g. diglycerol) in nitrogen stream at 200°C for 3 hr and thereafter at 230-250°C until the acid value reaches ≤0.5. The agent is a polyglycerol ester of a mixed fatty acid composed of oleic acid and lauric acid at a molar ratio of (2-8):(8-2) and the diester content in the polyglycerol ester is ≥30wt.%. A film having durable antifogging property and excellent heat-resistance and transparency can be produced by compounding 0.5-8.0 pts.wt. of the antifogging agent to a styrene resin, pelletizing the composition with a pelletizer and forming in the form of a film with an inflation- forming machine.
NAKAJIMA AKIO
OGAWA TAKASHI
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