Flame retardant composition

1. A flame retardant composition comprising: 30-50% by weight of a rubber; 5-10% by weight of an intumescent composition comprising a phosphate and a melamine polymer formed by combining melamine, formaldehyde, dicyandiamide, and aluminum hydroxide thereby forming the intumescent composition; 10-50% by weight of a ceramic forming mixture comprising CaO, Na 2 CO 3 , and Al(OH) 3 ; or the ceramic forming mixture comprises Na 2 CO 3 , Al(OH) 3 , and silica; 2-10% by weight of at least one glass additive selected from glass frit, glass fiber, and glass powder; and 15-35% by weight of layered silicate nanoparticles, wherein the rubber is optionally crosslinked, the flame retardant composition optionally comprises between 1-2% by weight of an antioxidant, and the weight percentages of the rubber, the intumescent composition, the ceramic forming mixture, the at least one glass additive, the layered silicate nanoparticles, and optionally the antioxidant are based on the total weight of the rubber, the intumescent composition, the ceramic forming mixture, the at least one glass additive, the layered silicate nanoparticles, and optionally the antioxidant in the flame retardant composition.

2. The flame retardant composition of claim 1 , wherein the rubber is selected from the group consisting of silicone, ethylene vinyl acetate, a thermoplastic polyurethane, natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, polybutadiene rubber, ethylene-propylene-conjugated diene terpolymer rubber, butyl rubber, halogenated butyl rubber, fluorine rubber, epichlorohydrin rubber, acrylonitrile-butadiene rubber, and a terpolymer of ethylene, propylene and a diene elastomer.

3. The flame retardant composition of claim 1 , wherein the rubber is crosslinked with a trialkenyl isocyanurate, an alkenyl alkoxy silane, or an aminoalkyl alkoxy silane, wherein the crosslinker is present at 0.5-3% by weight based on the total weight of the crosslinked rubber, the intumescent composition, the ceramic forming mixture, the at least one glass additive, the layered silicate nanoparticles, and optionally the antioxidant in the flame retardant composition.

4. The flame retardant composition of claim 1 , wherein the intumescent composition is prepared by combining 10-20% by weight of melamine, 15-20% by weight of dicyandiamide, 45-55% by weight of formaldehyde, 10-20% by weight of ammonium phosphate, and 1-2% by weight of aluminum hydroxide based on the total weight of the melamine, dicyandiamide, formaldehyde, ammonium phosphate, and aluminum hydroxide used to prepare the intumescent composition.

5. The flame retardant composition of claim 1 , wherein the ceramic forming mixture comprises 5-10% by weight of CaO, 10-15% by weight of Na 2 CO 3 , and 5-10% by weight of Al(OH) 3 based on the total weight of the rubber, the intumescent composition, the ceramic forming mixture, the at least one glass additive, the layered silicate nanoparticles, and optionally the antioxidant in the flame retardant composition; or the ceramic forming mixture comprises 5-15% by weight of Na 2 CO 3 , 3-7% by weight of Al(OH) 3 , and 3-7% by weight of silica based on the total weight of the rubber, the intumescent composition, the ceramic forming mixture, the at least one glass additive, the layered silicate nanoparticles, and optionally the antioxidant in the flame retardant composition.

6. The flame retardant composition of claim 1 , wherein the layered silicate nanoparticles comprises at least one material selected from the group consisting of mica, montmorillonite and wollastonite.

7. The flame retardant composition of claim 1 , wherein the flame retardant composition comprises: 30-50% by weight of a rubber selected from the group consisting of silicone, ethylene vinyl acetate, and a thermoplastic polyurethane, wherein the rubber is crosslinked with 1-2% by weight of triallyl isocyanurate; 5-10% by weight of an intumescent composition, wherein the intumescent composition comprises 10-20% by weight of ammonium phosphate and a melamine polymer prepared by combining 10-20% by weight of melamine, 15-20% by weight of dicyandiamide, 45-55% by weight of formaldehyde, and 1-2% by weight of aluminum hydroxide based on the total weight of the melamine, dicyandiamide, formaldehyde, and aluminum hydroxide used to prepare the intumescent composition; 11-35% by weight of a ceramic forming mixture comprising 5-10% by weight of CaO, 10-15% by weight of Na 2 CO 3 , and 5-10% by weight of Al(OH) 3 ; or the ceramic forming mixture comprises 5-15% by weight of Na 2 CO 3 , 3-7% by weight of Al(OH) 3 , and 3-7% by weight of silica; 2-10% by weight of glass frit; and 15-35% by weight of a layered silicate nanoparticles selected from the group consisting of montmorillonite and wollastonite, wherein the weight percentages of the rubber, triallyl isocyanurate, the intumescent composition, the ceramic forming mixture, glass fit, and the layered silicate nanoparticles are based on the total weight of the rubber, triallyl isocyanurate, the intumescent composition, the ceramic forming mixture, glass frit, and the layered silicate nanoparticles in the flame retardant composition.

8. The flame retardant composition of claim 7 , further comprising 1-2% by weight of a phenolic antioxidant based on the total weight of the rubber, triallyl isocyanurate, the intumescent composition, the ceramic forming mixture, glass frit, the layered silicate nanoparticles, and the phenolic antioxidant in the flame retardant composition.

9. The flame retardant composition of claim 8 , wherein the phenolic antioxidant is pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).

10. The flame retardant composition of claim 7 , wherein the flame retardant composition is halogen-free; has a tensile strength between 7-8.5 MPa; an elongation at break between 230-310%; and the gas that is generated when the flame retardant composition is burned has a pH between 6.4-6.6.

11. A method of preparing the flame retardant composition of claim 1 , the method of comprising:

providing an intumescent composition comprising a phosphate and a melamine polymer formed by combining melamine formaldehyde, dicyandiamide, and aluminum hydroxide;

combining 5-10% by weight of the intumescent composition with 30-50% by weight of a rubber, 10-50% by weight of a ceramic forming mixture comprising CaO, Na 2 CO 3 , and Al(OH) 3 ; or the ceramic forming mixture comprises Na 2 CO 3 , Al(OH) 3 , and silica; 2-10% by weight of at least one glass additive selected from glass fit, glass fiber, and glass powder; and 15-35% by weight of layered silicate nanoparticles; and optionally 0.5-3% by weight of a crosslinking agent and 0.1-5% by weight of a radical initiator thereby forming a flame retardant precursor composition, wherein the weight percentages of the intumescent composition, the rubber, the ceramic forming mixture, the at least one glass additive, the layered silicate nanoparticles, optionally crosslinking agent, and optionally the radical initiator are based on the total weight of the intumescent composition, rubber, the ceramic forming mixture, the at least one glass additive, the layered silicate nanoparticles, optionally crosslinking agent, and optionally the radical initiator in the flame retardant precursor composition; and

curing the flame retardant precursor composition thereby forming the flame retardant composition.

12. The method of claim 11 , wherein rubber is selected from the group consisting of silicone, ethylene vinyl acetate, a thermoplastic polyurethane, natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, polybutadiene rubber, ethylene-propylene-conjugated diene terpolymer rubber, butyl rubber, halogenated butyl rubber, fluorine rubber, epichlorohydrin rubber, acrylonitrile-butadiene rubber, and a terpolymer of ethylene, propylene and a diene elastomer.

13. The method of claim 11 , wherein the crosslinking agent is selected from the group consisting of a trialkenyl isocyanurate, an alkenyl alkoxy silane, and an aminoalkyl alkoxy silane; and the radical initiator is present at 0.5-3% by weight and the radical initiator is an organic peroxide.

14. The method of claim 11 , wherein the intumescent composition is prepared by combining 10-20% by weight of melamine, 15-20% by weight of dicyandiamide, 45-55% by weight of formaldehyde, 10-20% by weight of ammonium phosphate, and 1-2% by weight of aluminum hydroxide in the presence of water at a temperature between 40-100° C. thereby forming the intumescent composition.

15. The method of claim 13 , wherein the ceramic forming mixture comprises 5-10% by weight CaO, 10-15% by weight Na 2 CO 3 , and 5-10% by weight of Al(OH) 3 relative to the weight of the flame retardant composition; or ceramic forming mixture comprises 5-15% by weight of Na 2 CO 3 , 3-7% by weight of Al(OH) 3 , and 3-7% by weight of silica relative to the weight of the flame retardant precursor composition.

16. The method of claim 11 , wherein the layered silicate nanoparticles comprise at least one material selected from the group consisting of mica, montmorillonite and wollastonite.

17. The method of claim 11 , wherein the method comprises:

providing an intumescent composition comprising 15-20% by weight of ammonium phosphate and a melamine polymer prepared by combining 13-17% by weight of melamine, 15-20% by weight of dicyandiamide, 47-53% by weight of formaldehyde, and 1-1.5% by weight of aluminum hydroxide in the presence of water at a temperature between 40-100° C.;

combining 5-10% by weight of the intumescent composition with 30-50% by weight of a rubber selected from the group consisting of silicone, ethylene vinyl acetate, and a thermoplastic polyurethane, 11-35% by weight of a ceramic forming mixture comprising 5-10% by weight of CaO, 10-15% by weight of Na 2 CO 3 , and 5-10% by weight of Al(OH) 3 ; or the ceramic forming mixture comprises 5-15% by weight of Na 2 CO 3 , 3-7% by weight of Al(OH) 3 , and 3-7% by weight of silica; 2-10% by weight of glass fit; and 15-35% by weight of layered silicate nanoparticles selected from the group consisting of montmorillonite and wollastonite; and optionally 1-2% by weight of triallyl isocyanurate; 0.3-5% by weight of di(tert-butylperoxyisopropyl)benzene; and 1-2% by weight of pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) thereby forming a flame retardant precursor composition, wherein the weight percentages of the intumescent composition, the rubber, the ceramic forming mixture, the glass frit, the layered silicate nanoparticles, optionally the triallyl isocyanurate, the di(tert-butylperoxyisopropyl)benzene, and the pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) are based on the total weight of the intumescent composition, the rubber, the ceramic forming mixture, the glass frit, the layered silicate nanoparticles, optionally the triallyl isocyanurate, the di(tert-butylperoxyisopropyl)benzene, and the pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) in the flame retardant precursor composition; and

curing the flame retardant precursor composition at a temperature of 100-200° C. thereby forming the flame retardant composition.

18. The method of claim 17 , wherein the step of curing the flame retardant precursor composition is conducted in a mold.