METHOD FOR MANUFACTURING A FIRE-RESISTANT MATERIAL BASED ON HOMOGENEOUS FOAM PRODUCTS
The object of the present invention is a method for producing a fire retardant on the basis of homogeneous foam products. In such a method, a glass is first reacted with an aqueous alkali metal hydroxide solution at temperatures above 50° C. The reaction product is extracted as a viscous mass, granulated, and cooled until a solid granulated product is obtained. According to the invention, the granules are furnished with a hydrophobic coating having a layer thickness of about. 20 μm to 500 μm and are particularly 50 μm to 200 μm and preferably 50 μm to 100 μm and are incorporated in a construction material as a fire retardant additive.
1 . A method comprising:
reacting a glass with an aqueous alkali metal hydroxide solution at a temperature above 50° C.,
extracting a reaction product a viscous mass, granulating and cooling the reaction product to form solid granules, and
furnishing the granules with a hydrophobic coating having a layer thickness of about 20 μm to 500 μm.
2 . A method according to claim 1 , further comprising
incorporating the granules into a foam product,
wherein the hydrophobic coating is added in a proportion of 0.5 wt % to 2 wt %, relative to the starting weight of the foam product.
3 . A method according to claim 1 , wherein the mixture of the glass and the aqueous alkali metal hydroxide solution is heated to temperatures of 120° C. to 250° C.
4 . A method according to claim 1 wherein the glass is a recycled glass, a synthetic glass, a mineral glass of natural origin, or a mixture thereof.
5 . A method according to claim 1 , wherein the glass comprises:
60 to 85 wt % SiO2,
4 to 27 wt % Na2O,
0 to 5 wt % K2O,
0 to 8 wt % CaO,
0 to 5 wt % Al2O3,
0 to 14 wt % B2O3,
0 to 20 wt % PbO,
0 to 5 wt % MgO, and
0 to 8 wt % BaO.
6 . A method according to claim 1 , wherein the hydrophobic coating comprises a non-water-dilutable silicone.
7 . A method according to claim 6 , wherein the non-water-dilutable silicone is applied as a coating and is introduced into the interior of the granules.
8 . A method according to claim 1 , wherein wollastonite, mica, or another filler or reinforcement agent is added to the mixture of the glass and the alkali metal hydroxide solution.
9 . A method according to claim 1 , further comprising:
incorporating the granules into a foam product,
wherein a starting mixture for the foam product comprises:
about 50 to 60 wt % glass;
about 15 to 20 wt % alkali metal hydroxide, dry,
about 20 to 35 wt % water, and
about 0.5 to 2 wt % of the hydrophobic coating.
10 . A method according to claim 1 , further comprising adding the granules to a polymer used as a construction material.
11 . A method according to claim 1 , further comprising incorporating the granules into a homogenous fire retardant foam product.
12 . A method according to claim 11 , further comprising incorporating the foam product into a construction product.
13 . A method according to claim 12 , wherein the construction product is a seal or a cable insulation material.
14 . A method according to claim 3 , wherein the mixture of the glass and the aqueous alkali metal hydroxide solution is heated in an autoclave under pressure of 2 to 15 bar.
15 . A method according to claim 9 , wherein the starting mixture further comprises about 5 to 10 wt % of filler and reinforcement agents.
16 . A method according to claim 10 , wherein the polymer is an elastomer.
17 . A method according to claim 10 , wherein the construction material is used to produce a seals or a cable insulation material.