Flame retardant radiation curable compositions
The invention relates to a flame retardant composition comprising at least one radiation curable polymer precursor and at least one halogenated flame retardant which is soluble in the composition and their use to make fire resistant glass laminates.
1. A radiation curable flame retardant composition comprising
(i) at least one polymer precursor comprising one or more oligomers having one or more (meth)acryl or vinyl groups, and
(ii) at least one aliphatic halogenated flame retardant additive which is soluble in said composition and which has a solubility in n-butylacrylate at 20° C. of at least 10 g/l,
wherein aliphatic halogenated flame retardant additives in the composition are present in a total amount of from 20 to 80% by weight, and
wherein at least one of the aliphatic halogenated flame retardant additives is a brominated flame retardant having a bromine content of at least 40% by weight.
2. The radiation curable composition according to claim 1 , wherein the one or more oligomers are selected from the group consisting of urethane (meth)acrylates, polyester (meth)acrylates and epoxy (meth)acrylates.
3. The radiation curable composition according to claim 1 , wherein the at least one aliphatic halogenated flame retardant additive is further characterized by having a solubility in acrylic acid at 20° C. of at least 10 g/l.
4. The radiation curable composition according to claim 1 , wherein the at least one aliphatic halogenated flame retardant additive is a halogenated alcohol.
5. The radiation curable composition according to claim 1 , wherein all of the aliphatic halogenated flame retardant additives in the composition are brominated flame retardants having a bromine content of at least 40% by weight.
6. The radiation curable composition according to claim 5 , wherein the brominated flame retardant is tribromoneopentyl alcohol.
7. The radiation curable composition according to claim 1 comprising (i) at least one polymer precursor comprising (ia) one or more oligomers having one or more (meth)acryl groups and/or (ib) one or more monomers having one or more (meth)acryl groups,
wherein the total amount of the polymer precursors in the composition is from 20 to 80% by weight.
8. The radiation curable composition according to claim 7 , wherein the at least one polymer precursor comprises at least 20% by weight of one or more (meth)acrylated monomers selected from the group consisting of mono-, di-, tri- and tetra-(meth)acrylates.
9. The radiation curable composition according to claim 7 , wherein the at least one polymer precursor comprises at least 5% by weight of one or more oligomers selected from the group consisting of urethane(meth)acrylates, polyester (meth)acrylates and epoxy (meth)acrylates.
10. The radiation curable composition according to claim 9 , wherein the oligomer is selected from the group consisting of urethane (meth)acrylates and epoxy (meth)acrylates, and
wherein the oligomer has an elongation break of 10 to 500%.
11. The radiation curable composition according to claim 9 , wherein the oligomer is an aliphatic urethane acrylate having a molecular weight of 1000 to 10000.
12. The radiation curable composition according to claim 1 , wherein no phosphorus containing flame retardant additives are present.
13. The radiation curable composition according to claim 1 , wherein aliphatic halogenated flame retardant additives in the composition are present in a total amount of from 30 to 70% by weight.
14. The radiation curable composition according to claim 1 , wherein the composition contains the at least one aliphatic halogenated flame retardant additive and at least one aromatic halogenated flame retardant additive.