METHOD FOR PREPARING POLYURETHANE PREPOLYMER FOR PROTECTIVE COVER Russian patent published in 2004 - IPC

FIELD: polymers.

SUBSTANCE: invention relates to methods for preparing polyurethane prepolymers that are designated for making covers used for protection of metallic, concrete, wood, glass surfaces against effect of different atmosphere and corrosion media, corrosion, static electricity, abrasive wear and can be used as protective internal and external cover of pipelines, capacities and cisterns, engineering and hydrotechnical buildings, energetic units, port buildings, roofing iron and rood tiles and as a decorative cover also. Method is carried out by mixing hydroxyl-containing component with hydroxyl number 32-37 KOH/g Laprol 5003 or Laprol 4503 with white spirit followed by addition to the prepared mixture polyisocyanate based on 4,4'-diphenylmethanediisocyanate with the content of NCO-groups 29.5 g/100 g, not less, and synthesis is carried out at stirring up to the content of mass part of isocyanate NCO-groups in prepolymer 7.5-11.5%. Invention provides preparing prepolymer with stable indices (for a year, not less).

EFFECT: improved preparing method, valuable properties of prepolymer.

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