METHOD OF PRODUCING POLYISOCYANATE BLOCKED WITH ε-CAPROLACTAM Russian patent published in 2012 - IPC C07C263/18 C07C265/12 C07C265/14 C08G18/80 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing polyisocyanate blocked with ε-caprolactam, whose melt can be used in tyre and rubber industry to increase adhesion of rubber to synthetic fibre. The method involves reaction in molten state of di- and polyisocyanate with ε-caprolactam, where the additional blocking agents used are the product of reaction of adipic and terephthalic acid in form of a melt obtained beforehand in ε-caprolactam at temperature 150-160°C under a vacuum for 4 hours, with the following ratio of ingredients, pts.wt: 80,00 - ε-caprolactam, 9,40 - adipic acid and 10.60 - terephthalic acid, where the blocking reaction takes place in a homogeneous melt at temperature 90-100°C for 10 minutes, followed by thermostatic control at 100°C for 50 minutes, with the following quantitative ratio of blocking ingredients, pts.wt: 42.00-52.01 - di- and polyisocyanate, 41.54-56.50 - ε-caprolactam and 1.50-6.99 - said product of reaction of adipic and terephthalic acid in form of a melt obtained beforehand in ε-caprolactam.

EFFECT: obtaining polyisocyanate blocked with ε-caprolactam, with improved adhesion characteristics.

3 ex, 3 tbl