Mar-resistant polyesters

1,138,323. Unsaturated polyester-glycol diacrytate or dimethacrylate blends. AMERICAN CYANAMID CO. 14 April, 1966 [27 May, 1965; 22 July, 1965; 27 Sept., 1965; 21 Oct., 1965], No. 16460/66. Heading C3P. An unsaturated polyester blend comprises (1) the esterification reaction product of fumaric acid, or a mixture of fumaric and succinic acids in molar ratios of 3 : 1 to 1 : 3, and a polypropylene glycol, said reaction product having an acid number below 30 and (2) a glycol diacrylate or dimethacrylate in amount of from 10 to 40% by weight, based on the total weight of (1) and (2). The polypropylene glycol is preferably the secondary isomer of a C 6 to C 39 - polypropylene glycol. The glycol diester is derived from, e.g. a C 4 to C 8 -polyglycol or a C 2 to C 4 -monoglycol. The blend may also contain 1 to 5% by weight of a styrene, e.g. a methyl- or halo-styrene. The blend may comprise a small amount of another acid, e.g. phthalic, adipic, acetic or methacrylic acid. The blend is applied to plastic substrates and cured. In Examples 1 to 10, a blend comprising (1) a fumaric acid-tripropylene glycol polyester and ethylene glycol dimethacrylate, (2) a fuamaric acid-sec-sec-isomer of dipropylene glycol polyester and triethylene glycol dimethacrylate, (3) a fumaric acid-octapropylene glycol polyester, tetraethylene glycol dimethacrylate and styrene, (4) a fumaric aciddipropylene glycol polyester, tetraethylene glycol dimethacrylate and methacrylic acid, (5) a fumaric acid-decapropylene glycol polyester and triethylene glycol dimethacrylate, (6) a fumaric acid-tridecapropylene glycol polyester, polyethylene glycol dimethacrylate and alpha-methyl styrene, (7) a fumaric acidsec.-sec.-isomer of tripropylene glycol polyester and triethylene glycol diacrylate, (8) a fumaric acid-sec.-sec.-isomer of tetrapropylene glycol polyester and ethylene glycol dimethacrylate, (9) a fumaric acid-tripropylene glycolneopentyl glycol polyester and diethylene glycol diacrylate or (10) a fumaric acid/1,2-hexanediol/ sec.-sec.-isomer of dipropylene glycol polyester and polyethylene glycol diacrylate is mixed with benzoyl peroxide, applied to a polymethyl methacrylate sheet and cured by heating. A polyester derived from fumaric acid, succinic acid and dipropylene glycol is blended in Examples 11, 13 and 14 with ethylene glycol dimethacrylate, optionally styrene, and benzoyl peroxide, and cured to form a cast sheet. In Example 12, a fumaric acid-succinic acidtripropylene glycol polyester