| 摘要 |
Parent patent discloses non-flammable acrylic glass consisting of a mixt. contg., by wt., (1) 60-97% copolymer of (a) 50-87% Me methacrylate or its mixt. with one Br-free radically polymerisable monomer, (b) 10-40% polymerisable Br cpd., and (2) 40-3% H3PO4 or its esters or an organic phosphonic acid and opt. standard additives. In present modification, Br cpd. (1b) is tribromoneopentyl acrylate (I) or-methacrylate (I'), opT. in addn. to cpds. having general formula CH2=CR-(COO)n-ArBrm (where R is H or lower alkyl, Ar is opt. substd. Ph, n=O or 1 and m is 1 to 5). The vicat softening temps. of the copolymers of (I) or (I') with Me methacrylate are lowered only slightly (2); (ii) the flame-resistance of acrylic glass is improved by the synergetic action of (I) or (I') with (2); (iii) (I) and (I') are soluble in Me methacrylate and do not deviate appreciably therefrom w.r.T. polymn. behaviour; and (iv) No HBr is formed on working at 150-250 degrees C. |
