Pigmentable low-shrinkage unsaturated polyester resin composition
AssigneesTokyo Shibaura Electric Co., Ltd., Toshiba Chemical Products Co., Ltd.
InventorsMoriyasu Wada, Katuya Kumagai, Takashi Kamo
Life of this patent
Estimating the term…
Abstract
An unsaturated polyester resin composition comprises a mixture of a particular unsaturated polyester, an unsaturated monomer copolymerizable with the unsaturated polyester and polystyrene having a certain particle size in specific amounts. The unsaturated polyester is a reaction product of a dicarboxylic acid component containing .alpha.,.beta.-unsaturated dicarboxylic acid with a glycol component containing certain amounts of neopentyl glycol and 2,2-bis(4-hydroxycyclohexyl) propane. The resin composition exhibits favorable properties such as low shrinkage upon curing, good colorability and good storage stability, and is useful particularly in formulating premixed molding compounds.
Claims9
A pigmentable low-shrinkage unsaturated polyester resin composition comprising a mixture of:
- 25 to 70% by weight of unsaturated polyester based on a reaction product of a dicarboxylic acid component comprising .alpha.,.beta.-unsaturated dicarboxylic acid with a glycol component comprising, on the basis of the total amount of the glycol component, 15 to 70 mol% of neopentyl glycol and 10 to 30 mol% of 2,2-bis(4-hydroxycyclohexyl) propane;
- 60 to 18% by weight of unsaturated monomer copolymerizable with the unsaturated polyester;
- and
- 45 to 4% by weight of polystyrene or a butadiene modified polystyrene having such a particle size as to pass through a 50-mesh screen.
A bulk molding compound comprising 18 to 35% by weight of composition of claim 7 and 5 to 30% by weight of glass fibers.
A sheet molding compound comprising 25 to 40% by weight of composition of claim 7 and 20 to 40% by weight of glass fibers.
Dependencies are inferred from the claim text.