Paint composition
Fire retardant paint compositions and coatings containing acrylic modified polysiloxane, polyphosphate salt, expandable graphite, and fire retardant additives are provided. The paint compositions find use in protecting a substrate against fire and exhibit excellent adhesion to substrates and long term weather resistance.
1 . A fire retardant paint composition comprising:
a) about 20 wt. % to about 40 wt. % of one or more acrylic modified polysiloxane binders, wherein the one or more acrylic modified polysiloxane binders comprise a siloxane backbone functionalized with about 0.5 wt. % to about 10 wt. % acrylic groups;
b) about 5 wt. % to about 20 wt. % expandable graphite;
c) about 5 wt. % to about 20 wt. % of one or both of ammonium polyphosphate or melamine polyphosphate having a solubility in water of less than 2 wt. % at 20° C.;
d) about 5 wt. % to about 15 wt. % of aluminium trihydrate; and
e) about 10 wt. % to about 30 wt. % water.
2 . The fire retardant paint composition according to claim 1 comprising:
a) about 20 wt. % to about 40 wt. % one or more acrylic modified polysiloxane binders;
b) about 10 wt. % to about 20 wt. % expandable graphite;
c) about 5 wt. % to about 20 wt. % of one or both of ammonium polyphosphate or melamine polyphosphate having a solubility in water of less than 2 wt. % at 20° C.;
d) about 5 wt. % to about 15% wt. % of aluminium trihydrate; and
e) about 10 wt. % to about 30 wt. % water.
3 . The fire retardant paint composition according to claim 1 , wherein the one or more acrylic modified polysiloxane binders comprise one or more of acrylic modified polydimethylsiloxane, acrylic modified polymethylhydrogensiloxane, acrylic modified polydiethylsiloxane, acrylic modified polyphenylmethylsiloxane, and acrylic modified polydiphenylsiloxane.
4 . The fire retardant paint composition according to claim 1 , wherein the one or more acrylic modified polysiloxane binders comprise acrylic modified polydimethylsiloxane.
5 . The fire retardant paint composition according to claim 1 , wherein one or both of ammonium polyphosphate or melamine polyphosphate comprise a particulate polyphosphate having an average particle size (D50) of 5 to 50 micron.
6 . The fire retardant paint composition according to claim 1 , further comprising one or more auxiliaries selected from pigments, UV resistance additives, wetting agents, dispersing agents, biocides, rheology modifiers, coalescents, defoamers, and thickeners.
7 . The fire retardant paint composition according to claim 1 , wherein (e) comprises about 15 wt. % to about 25 wt. % water.
8 . A method of protecting a substrate or a coated substrate against fire comprising the step of coating the substrate or the coated substrate with the fire retardant paint composition according to claim 1 .
9 . The method according to claim 8 , wherein the substrate or the coated substrate is coated with the fire retardant paint composition by means of spraying or brushing.