Unsaturated polyester compositions comprising carboxylated cellulose ester

An unsaturated polyester composition which comprises

• (A) an unsaturated polyester which comprises the reaction product of
• (i) a diacid component which comprises about 60 to 80% by weight of an ethylenically unsaturated dicarboxylic acid comprising maleic acid, fumaric acid, or a mixture thereof and correspondingly about 20 to 40% by weight of an additional diacid comprising isophthalic acid, phthalic acid, adipic acid, or a mixture thereof, and
• (ii) a diol comprising ethylene glycol, propylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 2,2,4-trimethyl-1,3-pentanediol, or a mixture thereof;
• (B) a quantity of styrene which is sufficient to solvate said unsaturated polyester;
• and
• (C) at least about 0.5 percent by weight, based upon the total weight of the composition, of a carboxylated cellulose ester selected from carboxylated cellulose acetate, carboxylated cellulose propionate, carboxylated cellulose butyrate, carboxylated cellulose acetate propionate, carboxylated cellulose acetate butyrate, or a mixture thereof.

A process for the preparation of a cured unsaturated polyester composition which comprises the steps of:

• (a) reacting (i) a diacid component which comprises at least about 50% by weight of an ethylenically unsaturated carboxylic diacid with (ii) a diol component so as to form an unsaturated polyester resin;
• (b) dissolving said unsaturated polyester resin in a solvating quantity of a reactive solvent, the resulting solution further comprising at least about 0.5% by weight, based upon the total weight of said solution, of a carboxylated cellulose ester selected from carboxylated cellulose acetate, carboxylated cellulose propionate, carboxylated cellulose butyrate;
• carboxylated cellulose acetate propionate, carboxylated cellulose acetate butyrate, or a mixture thereof;
• and
• (c) curing said solution in the substantial absence of additional initiator so as to form a substantially clear, solid unsaturated polyester composition.

A process for the preparation of a cured unsaturated polyester composition which comprises the steps of:

• (a) reacting
• (i) a diacid component which comprises about 60 to 80% by weight of an ethylenically unsaturated dicarboxylic acid comprising maleic acid, fumaric acid, or a mixture thereof and correspondingly about 20 to 40% by weight of an additional diacid comprising isophthalic acid, phthalic acid, adipic acid, or a mixture thereof
• with
• (ii) a diol comprising ethylene glycol, propylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 2,2,4-trimethyl-1,3-pentanediol, or a mixture thereof
• so as to form an unsaturated polyester resin;
• (b) dissolving said unsaturated polyester resin in a solvating quantity of a reactive solvent comprising styrene, the resulting solution further comprising at least about 0.5% by weight, based upon the total weight of said solution, of a carboxylated cellulose ester selected from carboxylated cellulose acetate, carboxylated cellulose propionate, carboxylated cellulose butyrate, carboxylated cellulose acetate propionate, carboxylated cellulose acetate butyrate, or a mixture thereof;
• (c) curing said solution at a temperature of 60.degree. to 80.degree. C. until a substantially clear, solid unsaturated polyester composition is obtained.