Intumescent coating composition

Abstract

A liquid intumescent coating composition comprising the following components: (a) 25.0-75.0 volume % of one or more organic thermosetting polymer(s) and one or more curing agent(s) for the organic thermosetting polymer(s), (b) 1.0-70.0 volume % of a source of phosphoric or sulphonic acid, (c) 6.0-60.0 volume % of a source of boric acid, (d) 0-2.0 volume % of melamine or melamine derivatives, (e) 0-1.0 volume % of one or more isocyanurate derivatives, wherein the volume % of components (a), (b), (c), (d) and (e) is calculated on the total volume of the non volatile components in the coating composition. The thermosetting intumescent coating composition is suitable for protecting substrates against hydrocarbon fires, for example jet fires. The coating composition can be used without a supporting mesh. The present invention also relates to substrates coated the intumescent coating composition, and a method of protecting structures from fire.

Claims

1. A liquid intumescent coating composition comprising: (a) 25.0-75.0 volume % of one or more organic thermosetting polymer(s) and one or more curing agent(s) for the organic thermosetting polymer(s), and (b) 5.0-25.0 volume % of a source of phosphoric or sulphonic acid selected from one or more of sodium, potassium or ammonium phosphate or sulphate salts, and para-toluene sulphonic acid, (c) 10.0-50.0 volume % of a source of boric acid selected from one or more of boric acid, borate salts, and borosilicates, (d) 0 volume % of melamine or melamine derivatives, and (e) 0 volume % of one or more isocyanurate derivatives, wherein the organic thermosetting polymers do not comprise a polysiloxane, and wherein volume % is calculated on the total volume of the non-volatile components in the coating composition.

2. The intumescent coating composition of claim 1, wherein the borate salts are selected from one or more of the following: ammonium pentaborate, zinc borate, sodium borate, lithium borate, aluminium borate and magnesium borate.

3. The intumescent coating composition of claim 1 comprising 35.0-65.0 volume % of (a).

4. The intumescent coating composition of claim 1 further comprising 0-2.0 volume % of one or more amine functional blowing agents selected from dicyandiamide, urea and derivatives thereof (f).

5. The intumescent coating composition of claim 4 further comprising a total of 0-2.0 volume % of (i) said amine functional blowing agents selected from dicyandiamide, urea and derivatives thereof (f) and other blowing agents (g), wherein said other blowing agents (g) are selected from expandable graphite, sulfamic acid and tungstanate salts, and derivatives thereof.

6. The intumescent coating composition of claim 1 comprising glass fibres.

7. A coated substrate, wherein the substrate is coated with the intumescent coating composition of claim 1.

8. The coated substrate according to claim 7, wherein the coated substrate does not comprise a reinforcing mesh.

9. A method of protecting a structure from fire, the method comprising coating the structure with the intumescent coating composition of claim 1, and allowing the coating composition to cure.

10. The method of claim 9, wherein the coating is done without a reinforcing mesh, and the curing is done at ambient temperature.

11. The intumescent coating composition of claim 1 comprising 50.0-65.0 volume % of (a).

12. The intumescent coating composition of claim 1 comprising 10.0-25.0 volume % of (c).

Description

EXAMPLES

(1) Sample Preparation of Compositions 1-3 and Test Procedure

(2) Compositions 1, 2 and 3 comprising the components shown in Table 1 were made by first mixing all components except for the curing agent into the resin base by high speed dispermat. The polyamido amine curing agent was then added.

(3) TABLE-US-00001 TABLE 1 Sample Coating Composition # Component (Vol %) 1 2* 3* Epoxy Resin, 42.3 41.1 41.1 D.E.R.331 (DOW) (epoxy resin) Polyamido amine 22.7 22.0 22.0 Curing Agent having an amine equivalent weight of 93 g/mol Boric Acid 25.6 24.8 24.8 Ammonium 6.4 6.2 6.2 Polyphosphate Glass Fibre 3.0 2.9 2.9 THEIC 0 0 3.0 Melamine 0 3.0 0 *Comparative Examples

(4) Each test coating composition was then applied to 150 mm?100 mm?10 mm primed panels to a dry film thickness of 5 mm on both panel sides and panel edges. The samples were placed in a muffle furnace at a temperature of 1100? C. After 20 minutes the paints had fully intumesced to form a solid char. The integrity and expansion of each sample was assessed at this point.

(5) Test Results

(6) Sample 1) with no added melamine or THEIC formed an expanded, intumesced char with no visible cracking through to the metal substrate on the edges or sides.

(7) Sample 2) containing melamine showed early cracking and splitting along the edges of the panel. These splits were made worse as intumescence proceeded eventually causing char detachment.

(8) Sample 3) containing THEIC showed a number of cracks, extending down to the metal substrate. The expanded char remained on the substrate, but the cracks provided a clear route for breaching the thermal barrier of the char.