METHOD OF PRODUCING SOFT TO SEMI-RIGID POLYURETHANE INTEGRAL FOAMED PLASTICS Russian patent published in 2005 - IPC

FIELD: polymer production.

SUBSTANCE: invention relates to foamed polyurethane molded products with thickened edge zone with simplified density and clearly expressed more soft cellular core. Soft to semi-rigid polyurethane integral foamed plastics are prepared by interaction of (i) organic and/or modified organic polyisocyanates or their polymeric precursors with (ii) at least one polyol component with hydroxyl number 20 to 200 and functionality 2 to 6, if necessary in combination with (iii) at least one polyol component with hydroxyl number 201 to 899 and functionality 2 to 3, and also (iv) at least one component functioning as chain extension and having hydroxyl number or amine number 600 to 1850 and functionality 2 to 4 in amount 3 to 20% based on the summary weight of (ii) and (iii), and, if necessary, (v) known additives, activators, and/or stabilizers in presence of 0.05-0.6% water (based on summary weight of (ii) and (iii)) and mixtures of pore agents containing 1,1,1,3,3-pentafluorobutane and at least one other fluoroalkane in amount 0.2-10% of the summary weight of components (ii)-(v). Thus obtained foamed plastics with integral structure are characterized by Shore hardness of edge zone 30 to 90, rigidity in compression deformation 30 and 350 kPa, and apparent density 150 to 900 kg/m³.

EFFECT: increased assortment of foamed plastics.

7 cl, 1 tbl, 9 ex