Toughened composition
The instant invention relates to epoxy resin compositions comprising an epoxy resin, a block copolymer having at least one block predominantly composed of methyl methacrylate units or a core shell component and a hardener of the polyoxyalkyleneamine type. The epoxy materials cured from these compositions have high impact resistance.
1. Epoxy resin composition consisting of:
(a) 30 to 94.5% by weight, based on the amount of components (a), (b) and (c) of an epoxy resin liquid at room temperature having on average more than one 1,2-epoxide group in the molecule;
(b) a hardener-accelerator system consisting of a polyoxyalkylenediamine type hardener or a combination of a polyoxyalkylenediamine type hardener and a non-polyoxyalkyleneamine type hardener selected from a cycloaliphatic amine and an aromatic amine;
(c) an impact modifier consisting of an S-B-M block copolymer, an M-B-M block copolymer, a combination of an S-B-M block copolymer and at least one second polymer, or a combination of an M-B-M block copolymer and at least one second polymer, wherein the at least one second polymer is selected from the group consisting of an S-B block copolymer, an amine terminated butadiene acrylonitrile copolymer, a carboxyl terminated butadiene acrylonitrile, and combinations thereof; and
(d) optional additives selected from the group consisting of a degassing agent, fillers, pigments, dyes, flame retardant substances, antistatics, adhesion promoters, flow control agents, antioxidants, light stabilizers, fibers and combinations thereof.
2. Epoxy resin composition according to claim 1 wherein (a) is an aromatic epoxy resin.
3. Epoxy resin composition according to claim 1 wherein (b) is employed in amounts of 5 to 50% by weight, based on the amount of components (a), (b) and (c).
4. Epoxy resin composition according to claim 1 wherein (c) is employed in amounts of 0.5 to 20% by weight, based on the amount of components (a), (b) and (c).
5. Epoxy resin composition according to claim 1 wherein, per 100 parts by weight of the composition of (a), (b) and (c), components (a) and (b) are present in amounts of 70-99.5 parts by weight and component (c) in amounts of 0.5-30 parts by weight.
6. Epoxy resin composition according to claim 1 wherein an additive is present.
7. A method of preparing an epoxy resin composition according to claim 1 comprising the steps of:
blending an epoxy resin liquid having on average more than one 1,2-epoxide group in the molecule with an impact modifier consisting of an S-B-M, an M-B-M block copolymer, a combination of an S-B-M block copolymer and at least one second polymer, or a combination of an M-B-M block copolymer and at least one second polymer, wherein the at least one second polymer is selected from the group consisting of an S-B block copolymer, an amine terminated butadiene acrylonitrile copolymer, a carboxyl terminated butadiene acrylonitrile and combinations thereof at a temperature sufficient to fluidize the impact modifier until it has completely dissolved;
adding a hardener-accelerator system consisting of a polyoxyalkylenediamine type hardener or a combination of a polyoxyalkylenediamine type hardener and a non-polyoxyalkyleneamine type hardener selected from a cycloaliphatic amine and an aromatic amine and optionally adding additives selected from the group consisting of a degassing agent, fillers, pigments, dyes, flame retardant substances, antistatics, adhesion promoters, flow control agents, antioxidants, light stabilizers, fibers and combinations thereof to the resulting blend to obtain a homogeneous blend and to form the epoxy resin composition.
8. A method of preparing and curing an epoxy resin composition according to claim 1 comprising the steps of:
(a) blending an epoxy resin liquid having on average more than one 1,2-epoxide group in the molecule with an impact modifier consisting of an S-B-M block copolymer, an M-B-M block copolymer, a combination of an S-B-M block copolymer and at least one second polymer, or a combination of an M-B-M block copolymer and at least one second polymer, wherein the at least one second polymer is selected from the group consisting of an S-B block copolymer, an amine terminated butadiene acrylonitrile copolymer, a carboxyl terminated butadiene acrylonitrile and combinations thereof at a temperature sufficient to fluidize the impact modifier until it has completely dissolved;
(b) adding a hardener-accelerator system consisting of a polyoxyalkylenediamine type hardener or a combination of a polyoxyalkylenediamine type hardener and a non-polyoxyalkyleneamine type hardener selected from a cycloaliphatic amine and an aromatic amine and optionally adding additives selected from the group consisting of a degassing agent, fillers, pigments, dyes, flame retardant substances, antistatics, adhesion promoters, flow control agents, antioxidants, light stabilizers, fibers and combinations thereof to the resulting blend to obtain a homogeneous blend and to form the epoxy resin composition;
(c) applying the epoxy resin composition to a substrate or casting the epoxy resin composition in a mould; and
(d) applying heat to the epoxy resin composition to cure the epoxy resin composition.