Formulations comprising isosorbide-modified unsaturated polyester resins and low profile additives which produce low shrinkage matrices
View Patent ↗Formulations comprising an isosorbide-modified unsaturated polyester comprising maleic acid, fumaric acid, itaconic acid or maleic anhydride and isosorbide and one or more low profile additives. The formulations exhibit better shrink control in molding compound formulations with standard low profile additives than their non-isosorbide-modified analogues. These isosorbide-modified unsaturated polyester resins may be applied in molding compounds like sheet molding compounds or bulk molding compounds and may be components of fiber reinforced composites or other composite materials.
1. A formulation comprising a) an isosorbide-modified unsaturated polyester comprising maleic acid, fumaric acid, itaconic acid, maleic anhydride or combinations thereof; isosorbide; and glycol other than isosorbide; and b) one or more low profile additives,
wherein the isosorbide is present in an amount of about 10 mole % to about 60 mole % based on the total amount of glycol in the formulation and a sheet molding compound comprising the formulation expands when processed into a molded part by placing the sheet molding compound in a machined aluminum frame and molding the compound using 15 tons of pressure at 150° C. for 2 minutes.
2. The formulation of claim 1 further comprising a copolymerizable solvent.
3. The formulation of claim 2 wherein the copolymerizable solvent is selected from the group consisting of styrene, vinyl toluene, acrylic esters, divinyl benzene, multifunctional acrylates, methacrylates, diallylphthalate and combinations thereof.
4. The formulation of claim 1 further comprising non isosorbide-modified unsaturated polyester resin, vinyl ester resin or combinations thereof.
5. The formulation of claim 1 wherein the isosorbide-modified unsaturated polyester further comprises a dicarboxylic acid selected from the group consisting of isophthalic acid, terephthalic acid, adipic acid, succinic acid and combinations thereof.
6. The formulation of claim 1 wherein the isosorbide-modified unsaturated polyester further comprises succinic anhydride or phthalic anhydride.
7. The formulation of claim 1 wherein the glycol other than isosorbide is selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, hexanediol, butanediol and combinations thereof.
8. The formulation of claim 7 wherein the glycol is incorporated into the isosorbide-modified unsaturated polyester.
9. The formulation of claim 1 wherein the low profile additive is selected from the group consisting of polystyrene, polyesters, polyacrylates, polymethacrylates, polyvinyl acetate, polyurethanes, polyepoxides, polyglycols and combinations thereof.
10. The formulation claim 1 further comprising a chain extending compound.
11. The formulation of claim 10 wherein the chain extending compound is selected from the group consisting of epoxy resin, epoxidized vegetable oil, epoxidized fatty acid, epoxidized fatty acids ester, cycloaliphatic epoxide and combinations thereof.
12. The formulation of claim 11 wherein the epoxy resin comprises glycidyl ethers of bisphenol A.
13. The formulation of claim 10 wherein the chain extending compound comprises polyisocyanate.
14. A molding compound comprising the formulation of claim 1 .
15. The molding compound of claim 14 further comprising a component selected from the group consisting of a filler, a reinforcement material, a mold release agent, a viscosity modifier, a low shrink enhancer, an impact modifier, a pigment, a dye, an accelerating agent, a plasticizer and a stabilizer.
16. The molding compound of claim 15 wherein the filler is selected from the group consisting of CaCO 3 , clay, alumina, trihydrate, talc, wallostonite, carbon black, fumed silica, glass microsphere and combinations thereof.
17. The molding compound of claim 15 wherein the reinforcement material is selected from the group consisting of glass fiber, carbon fiber, boron nitride whisker, natural fiber and combinations thereof.
18. The molding compound of claim 15 wherein the mold release agent is selected from the group consisting of calcium stearate, zinc stearate, magnesium stearate, sodium stearate and combinations thereof.
19. The molding compound of claim 14 further comprising a polymerization initiator.
20. The molding compound of claim 19 wherein the polymerization initiator is selected from the group consisting of peroxide type, azo type and combinations thereof.
21. The molding compound of claim 19 wherein the polymerization initiator is selected from the group consisting of benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, lauryl peroxide, cyclohexanone peroxide, t-butyl perbenzoate, t-butyl hydroperoxide, t-butyl benzene hydroperoxide, cumene hydroperoxide, butyl peroctoate, azobisisobutyronitrile, 2-t-butylazo-2 -cyano-4-methylpentane, 4-5-butylazo-4-cyano-valeric acid and combinations thereof.
22. A composite article prepared by a process comprising the steps of: a) providing the formulation of claim 1 and b) curing the formulation.