GB2341186A - Fire protection composition - Google Patents

Abstract

A fire resistant formulation for application to a metal substrate, especially a structural element used in construction, comprises a first polymeric material and an intumescent formulation. The first polymeric material is preferably rubber, PVC, polyurethane, polyester, or phenolic resin. The intumescent formulation preferably comprises a phosphate polymer (e.g. ammonium polyphosphate), a blowing agent (e.g. melamine) and a carbon source (e.g. pentaerythritol and/or di-pentaerythritol). The first polymeric material has a Young's modulus of less than 50 GNm<SP>-2</SP>.

Description

2341186 FIRE PROTECTION The present invention relates to fire protection

and particularly, although not exclusively, provides a fire resistant formulation and methods of preparing and using the same.

It is known to use fire resistant paints to protect steel structures. Such fire resistant paints usually comprise either an organic solvent base or a water base and an intumescent material and are generally known as intumescent paints.

Intumescent paints are commonly painted onto steel structures after construction. There are three stages for application of intumescent coatings to steel structures. Firstly, the steel is pre-coated with a primer. Secondly, a layer of intumescent paint is applied on top of the primer, and thirdly, because of the soft nature of the intumescent paint, a third protective top coat or sealer is applied.

There are many disadvantages associated with intumescent paints. Firstly, the organic solvent base presents health and safety problems. In order to avoid the use of solvent based carriers, water based paints have been developed.

However, it is difficult to remove the water from the paint after application and before the top coat is applied. For paints applied after construction this is done by air drying the paint and can take a considerable length of time. Furthermore,' before the top coat is applied the paint is water soluble. Accordingly, for outside applications, the top coat must be applied before any rain can start to dissolve the paint.

Secondly, it is very time consuming applying three layers of paint to the structure. Furthermore, the degree of protection afforded by application of the paint after construction is dependent upon the diligence of the person applying the,paint. It is important that the layers of coating are applied evenly over the whole surface area.

Small omissions in the coating can drastically reduce the effectiveness of the paints in terms of the length of time for which the underlying steel structure is protected from the heat of the fire. Application of the fire resistant paint including primer and top coat before delivery of the steel components to the construction site has not been found to be an effective solution to this problem. The brittle nature of the three layer fire resistant paint system means that handling during storage and transportation of the coated structures frequently rdults in significant damage to the coating. This means that the coating needs to be patched up after construction and effectively results in the steel being coated twice.

A further use of fire resistant materials is for protection of electrical cables. Electrical cables often run between rooms and even between floors of buildings. In the event of a fire, not only is it important that electrical cables are not burned through so that electrical equipment continues to work, but fire can spread easily along cables from room to room and floor to floor. This is particularly true when the cables are surrounded by a rubber based coating or other highly flammable material.

Attempts to overcome this problem involve wrapping the cables in a ceramic material. The ceramic material insulates the cables against the heat of the fire and helps to keep them working. However, this method does not reduce the flammability of the PVC or rubber sheath around the conductive part of the cable and, accordingly, if the cable temperature rises too high, the sheath may bum in any event.

1 It is an object of preferred embodiments of the present invention to provide a fire resistant formulation which overcomes at least some of the problems associated with prior art fire resistant materials.

According to a first aspect of the invention, there is provided a fire resistant formulation comprising a first polymeric material and an intumescent formulation, wherein said first polymeric material has a Young's Modulus of less than 50GNin' or is vulcanisable to have a Young's Modulus of less than 50GNM-2.

Said Young's Modulus may be less than 25GNni-1, is suitably less than 15GNm2, is preferably less than 1OGNm', is more preferably less than 5GNnil and, especially, is 1GNM-2 or less.

Said Young's Modulus may be 0.001GNnrl or greater.

The tensile strength of said first polymeric material may be at least 5MNM-2, preferably at least 1OMNM-2, more preferably at least 14MNnil.

Said tensile sength may be less than 6OMNni', preferably less than SOMNni-1, more preferably 40MNni -2 or less.

The percentage elongation of said first polymeric material may be at least 100 %, preferably at least 300 %, more preferably at least 400 % and especially at least 600%.

The percentage elongation of said first polymeric material may be less than 1000%, preferably less than 950%, more preferably less than 900% and especially less than 800%. Suitably, the strain before fracture of the first polymeric material is at least 10 1, preferably at least 2.5, more preferably at least 4 and especially at least 5.5. Suitably, the strain before fracture of the first polymeric material is less than 12, preferably less than 10, more preferably less than 9 and especially less 15 than 8. 1 Suitably, the strain before fracture of the first polymeric material is approximately 7. 20 Suitably, the elastic limit of the first polymeric material is at least 5MNM-2, preferably at least 1OMNm-2, more preferably at least 14MNM-2, and especially at least 18MNml. Suitably, the lastic limit of the first polymeric material is less than 70MNni', 25 preferably less than 50MNmI, more preferably less than 35MNnr 2, and especially less than 25MNni.

1 Suitably, the elastic limit of the first polymeric material is approximately 20MNin-1.

Preferably, the first polymeric material is arranged such that its ratio of stress/strain increases as the temperature of the material increases.

1 Said first polymeric material is preferably an organic polymeric material.

Said first polymeric material is preferably not a thermosetting material.

Said first polymeric material is preferably a rubber. Said rubber may be natural or synthetic. Said rubber may be EDPM or neoprene.

Where said first polymeric material is vulcanisable it may comprise a non15 vulcanised or,partially vulcanised rubber. The rubber may be in the form of a powder, a water based solution or liquid rubber.

The polymeric material may be in the form of a solid or liquid. Preferably, the polymeric material is in the form of a liquid. If the polymeric material is in the form of a solid, the solid is preferably a free flowing powder.

The fire resistant formulation is preferably in the form of a liquid when applied to a substrate.

1 The fire resistant formulation may comprise at least 2wt%, preferably at least 4wt%, more preferably at least 7wt %, especially at least lOwt% of the intumescent formulation.

i 1, The fire resistant material may comprise less than 75wt%, preferably less than 60wt%, more preferably less than 5% and especially less than 45wt% of the intumescent formulation.

When applied as a coating, the fire resistant formulation may expand by at least 100%, preferably at least 600%, more preferably at least 1200%, especially at least 2000% when subjected to heating andlor burning.

When applied as a coating, the fire resistant formulation may expand by less than 5000%, preferably less than 4500%, more preferably less than 3750% especially less than 3250%.

Suitably, the intumescent formulation comprises a first component comprising a phosphate material having at least lOwt% phosphorous.

The first co ' onent is preferably a phosphate salt, for example, with an alkali Mp metal, with sodium and potassium being preferred, or especially with ammonia.

The first component is preferably a phosphate polymer, for example, it may be a polyphosphate. A preferred polyphosphate has the formula NP03)y where M represents an alkali metal, for example sodium or potassium, or NH4; and y represents an integer. Preferably, M represents NH4.

-25 y may be greater than 50, suitably greater than 200, preferably greater than 400, more preferably greater than 600 and especially greater than 800.

The first component is suitably substantially insoluble in water. The first component is preferably a solid at 250C and ambient pressure.

The phosphate material of the first component may be encapsulated by, for example, a polymer resin. Preferred encapsulation means are arranged to produce non-flammable gases when degraded by heat and/or flame, and suitably do not produce oxygen gas on degradation. Preferred encapsulation means contain nitrogen and are arranged to produce nitrogen gas when degraded. Advantageously, the nitrogen gas dilutes the oxygen available to the flame during burning. A preferred encapsulating material comprises a melamine-containing resin, especially a melamine-formaldehyde resin.

The first component may comprise at least 13wt%, suitably at least 16wt%, preferably at least 19wt%, more preferably at least 25wt%, especially at least 28wt% phosphorous.

The first component may comprise less than 50wt%, suitably less than 40wt%, preferably less than 37wt%, more preferably less than 34wt% and especially less than 32wt% phosphorous.

The first component may comprise at least 5wt%, suitably at least 8wt%, preferably at least 11 wt %, more preferably at least 14wt % and especially at least 15wt% nitrogen.

The first component may comprise less than 40wt%, suitably less than 30wt%, prefrably less than 25wt%, more preferably less than 21wt% and especially less than 18wt% nitrogen.

I Suitably, the inturnescent formulation comprises a second component which second component comprises a blowing agent.

The second component suitably produces a gas when heated and/or burned.

Preferably, the second component produces a non-flammable gas. The gas is suitably nitrogen and/or hydrogen. Preferably, the second component does not produce oxygen.

Suitably, the second component comprises at least 50wt%, preferably at least 55wt%, more preferably at least 60wt % and especially at least 66wt% nitrogen.

The second component suitably comprises less than 90wt%, preferably less than 84wt%, more preferably less than 78wt%, and especially less than 70wt % nitrogen.

I The second component may comprise at least 15wt%, suitably at least 18wt%, preferably at least 23wt%, more preferably at least 26wt% and especially at least 28wt% carbon.

The second component suitably comprises less than 80wt%, preferably less than 65wt%, more preferably less than 50wt% and especially less than 45wt% carbon.

The second component may comprise at least 2wt%, preferably at least 3wt%, more preferaly at least 4wt% and especially at least 5wt% hydrogen.

Suitably, the second component comprises less than 20wt%, preferably less than 15wt%, more preferably less than 12wt% and especially less than hydrogen.

Suitably, the second component comprises only carbon, nitrogen and hydrogen atoms.

Suitably, the second component is substantially non-flammable. The second component is suitably a solid at 250C and ambient pressure.

Preferably, the second component is a melamine. Optionally, the second component comprises substituted melamine. Preferably, the second component comprises melamine which has not been substituted.

Suitably, the intumescent formulation comprises a third component comprising a carbon source.

A The third component is suitably present to promote production of a stable and carbonaceous char when the fire resistant material is heated and/or burned.

Suitably, the third component is a polyhydric alcohol. The polyhydric alcohol preferably comprises at least four hydroxyl groups. Suitably, the polyhydric alcohol may comprise at least five or preferably at least six hydroxyl groups.

Suitably, the polyhydric alcohol comprises less than 20, preferably less than 14, more preferably less than 10 and especially less than 8 hydroxyl groups.

A The third component is suitably solid at 25'C and ambient pressure.

The third component preferably comprises pentaerythritol, dipentaerythriol or a mixture thereof.

The ratio of the first component to the second component is suitably within the range 03-20: 0.05-10, preferably in the range of 1-15: 0.1-5, more preferably in the range of 1-10: 0.54 and especially in the range of 1-5: 03 2.

The ratio of the first component to the third component is suitably within the range 03-20: 0.05-10, preferably in the range of 1-15: 0.1-5, more preferably in the range of 1-10: 0.54 and especially in the range of P5: 03-2.

Suitably, the ratio of the second component to the third component is in the range of 9-1: 9-1, more preferably in the range of 8-2: 8-2, especially in the range of 6-4: 6-4.

Suitably, the ratio of the first, second and third components is in the range of 03-20: 0.05-10: 0.05-10, preferably in the range of 1-15: 0.13: 0.13, more preferably in the range of 1-10: 0.54: 0.54 and especially in the range of 1 5: 03-2.

The intumescent formulation suitably includes at least 30wt%, suitably at least 35wt%, preferably at least 40wt%, more preferably at least 44wt% and especially at least 46wt% of the first component.

The intumescent formulation suitably includes less than 80wt%, preferably less than 70wt%, more preferably less than 60wt% and especially less than 50wt% of the first component.

1 - 11 The intumescent formulation suitably comprises at least lOwt%, suitably at least 15wt%, preferably at least 1.9wt%, more preferably at least 2% and especially at least 27wt% of the second component.

The intumescent formulation suitably comprises less than 50wt%, preferably less than 40wt%, more preferably less than 35wt% and especially less than 30wt% of the second component.

1 The intumescent formulation suitably comprises at least lOwt%, suitably at least 15wt%, preferably at least 19wt%, more preferably at least 24wt% and especially at least 27wt% of the third component.

The intumescent formulation suitably comprises less than 5Owt%, preferably less than 40wt%, more preferably less than 35wt% and especially less than 30wt% of the third component.

The ratio of intumescent formulation to polymeric material is suitably in the range of 0. 053:1-9, preferably in the range of 0. P3: 1 -5 and more preferably in the range of 0. 1-11-3.

The fire resistant formulation suitably comprises at least 5wt%, preferably at least lOwt%, more preferably at least 20wt% and especially at least 30wt% intumescent formulation.

The fire resistant formulation suitably comprises less than 60wt%, preferably less than 50wt%, more preferably less than 45wt% and especially less than 40wt% intumescent formulation.

1 12- The fire resistant formulation suitably comprises at least 40wt%, preferably at least 5Owt%, more preferably at least 6Owt% and especially at least 70wt% of the first polymeric material.

The fire resistant formulation suitably comprises less than 95wt%, preferably less than 85wt%, more preferably less than 80wt% and especially less than 75wt% of the first polymeric material.

The fire resistant formulation may optionally comprise a minor amount of silica. Suitably, the silica is in the form of a powder. The silica is suitably fused silica.

Addition of a proportion of silica to the fire resistant formulation may produce a more stable char. However, the amount of silica should be limited otherwise its inclusion may increase the stiffness of the material to too high a level.

The fire resistant formulation may optionally comprise a minor amount of aluminium trihydrate. Addition of a minor amount of aluminium trihydrate to the formulation may effect a suppression of surface flame.

According to a second aspect of the invention, there is provided a fire resistant formulation comprising a first polymeric material and an intumescent formulation, wherein said first polymeric material is a rubber.

Said rubber may be non-vulcanised, partially vulcanised or substantially fully vulcanised.

1 Said first polymeric material of the second aspect and/or said intumescent formulation may have any feature of the first polymeric material and/or said intumescent formulation of said first aspect.

According to a third aspect of the invention, there is provided a fire resistant formulation comprising a first polymeric material, for example selected from the group comprising PVC, polyurethane, polyester and phenolic-resins, and an intumescent formulation.

1 According to a fourth aspect of the invention there is provided a method of manufacturing a fire resistant formulation wherein a first polymeric material and an intumescent formulation are contacted, for example blended, with one another.

The polymeric material may be in the form of a solid or a liquid. If the material is in the form of a solid, it may be in the form of a free flowing powder. Preferably, the intumescent formulation is in the form of a solid, more preferably, in the form of a free flowing powder.

1 A fifth aspect of the invention provides an intumescent formulation comprising first, second and third components, wherein said first component comprises a phosphate material having at least lOwt% phosphorous, said second component comprises a blowing agent and said third component comprises a carbon source.

Each of the first, second or third components may be in the form of a solid or liquid. Preferably each of the first, second and third components is in the form of a solid, more preferably in the form of a free flowing powder.

1 A sixth aspect of the invention provides a method of manufacturing an intumescent formulation, wherein first, second and third components are blended together, said first component comprising a phosphate material comprising at least lOwt% phosphate, said second component comprising a blowing agent and said third component comprising a carbon source.

Whilst each of the first second and third components may be in the form of a solid or liquid, each of the components is preferably in the form of a solid, more preferably in the form of a free flowing powder.

1 Blending of the first, second and third components may be achieved by feeding all of the components, either separately or simultaneously, to a rotary blender; preferably, a rotary dram blender. Advantageously, blending is carried out for sufficient time to provide a substantially homogenous mixture of the three components.

Use of a fire resistant formulation in accordance with the first and/or second and/or third aspects of the present invention is particularly advantageous for all applications where a flexible fire resistant material is required or where a shock absorbing material is required. A fire resistant formulation in accordance with the present invention may be used, for example, as a coating for metal, as a cover for electrical cables, as an adhesive and/or sealant for holding sheets of glass in windows and doors and as a sealant around door frames.

Surprisingly, it has been found that when rubber is incorporated in a fire resistant material in accordance with the present invention the rubber does not bum with its characteristic black smoke. Rather, the presence of the I intumescent formulation renders the rubber resistant to combustion. Furthermore, the presence of the char acts as a filter so that when the underlying rubber material eventually burns, the characteristic black smoke is filtered through the char.

A seventh aspect of the invention provides a substrate coated with a fire resistant formulation, which fire resistant formulation comprises a polymer and an intumescent formulation which polymer has a Young's Modulus of less than 50GNm-1.

1 An eighth aspect of the present invention provides a method of manufacturing a fire resistant material, wherein a surface of a substrate is coated with a fire resistant formulation to provide a fire resistant material, said fire resistant formulation comprising a polymer and an intumescent formulation said polymer having a Young's modulus of less than 5OGNmI.

A plurality of layers of fire resistant formulation may be applied to the substrate to provide a fire resistant coating. Suitably, each layer is cured before application of the subsequent layer. Suitable methods of curing included heaiing in an oven and air drying at ambient temperature and humidity.

Suitably, the dry film thickness of the fire resistant coating on the substrate is at least lmm, is more preferably at least 2mm, and especially is at least 3mm.

Suitably, the, thickness of the fire resistant coating is less than l0mm, preferably less than 8mm, more preferably less than 6mm and suitably less than 5mm thick.

The substrate may be a metal substrate. Suitably, a metal substrate comprises a metal which is conventionally used in construction, for example of buildings. Advantageously, the metal is steel.

Suitably, the metal substrate is treated to clean and/or roughen the surface before application of the fire resistant formulation. Suitable treatment methods inclde shot blasting. The fire resistant material may be applied to the metal substrate by either brushing, rolling or spraying the material onto the substrate. The substrate could also be dipped into the fire resistant material. If the fire resistant material is sprayed onto the substrate, the 15 material is preferably applied by means of a low pressure air spray.

The metal substrate may be in the form of structural elements, which elements may be coated with the fire resistant coating following manufacture before being transferred to the building site. The structural elements may be 20 partially or wholly coated with the fire resistant formulation.

An advantage of using rubber in the fire resistant formulation means that handling of the metal after application of the fire resistant coating, for example during storage and transfer to the building site as well as during 25 construction, is less likely to result in damage to the fire resistant coating.

The fire resistant formulation is suitably applied to a substrate to provide a fire resistant coating. When the coating is subjected to heating and/or burning I the thickness of the coating increases and an insulation layer is formed on the surface of the coating. The insulation layer is generally known as the "char". The char is non-combustible and therefore, will not support a flame and win hence restrict the spread of the flame. The thickness of the coating after heating and/or burning is important because the distance between the char and the underlying substrate affects the degree of insulation of the substrate from the heat and therefore the time period for which the substrate is protected from the heat. The formulation of the char is also important. Firstly, it is important that the char is stable when subjected to the vortex created during the fire. Secondly, the char suitably provides a firm, regular carbonaceous crust, which crust is of uniform height and without fissures, voids or cracks. Any breaks or gaps in the carbonaceous crust could reduce the insulating effect of the insulating layer.

The invention will now be described by way of example and with reference to Figure 1, which illustrates a sample of a coated metal substrate as tested for fire resistance.

The following products are referred to hereinafter:

Exolit AP 462 (Trade Mark) - ammonium polyphosphate ((NH4P03)ywhen y > 1000) microencapsulated with melamine-formaldehyde resin. The product is a white powder and is understood to contain 1.0% (max) water and has a maximum acid value of 0.5 mg KOH/g measured on a 10% aqueous suspension. The product was obtained from Clariant Specialities Ltd of Hounslow, U.K.

A Melamine was provided by BASF of Cheshire, U.K. The melamine was in the form of 4 white, odourless powder. The solubility of the melamine at 200C is 3.2 g/1 and the density of the melamine at 201C is 1.574g/cm3.

Dipentaerythritol was supplied by Perstorp Specialty Chemicals of Perstorp, Sweden. The dipentaerythritol was in the form of a fine, white, crystalline powder. The material has a solubility of 0.2wt% at 25oC. The dipentaerythrotol has a di-pentaerythritol content of 90-100%, a pentaerythritol contnet of 1-10% and a tri-pentaerythritol contnet of 03%.

Ejample 1 - Preparation of an intumescent formulation 1 Exolit AP 462 (46g, 46wt%), melamine (27g, 26wt%) and di-pentaerythriol (27g,27wt%) were placed in a horizontally mounted rotary drum blender.

Blending was carried out at approximately 30 revolutions per minute for 2 hours. A fully homogenous mixture was obtained to provide an intumescent formulation in the form of a powder.

ExaLnple, 2- EMaration of a fire resistant formulation 20 The intumescent powder of Example 1 was added to a water-based prevulcanised rubber solution by means of a low speed, low shear mixer. Alternatively, the intumescent powder could be added to powdered rubber at the compounding stage of the rubber treatment by means of a blending mixer.

Three different formulations of material were produced comprising respectively, 100, 200 and 300 parts by weight of intumescent material per 1000 parts by weight of rubber solution.

- 19 ExMle 3 - Application of a fire resistant formulation to a steel substrate.

Universal steel sections type 203 x 203 (Hp/A of 200) and weight 293kg were shot blasted to provide a roughened surface and to remove any rust, debris, dust or grease.

A coating of the fire resistant material of Example 2 comprising 300 parts by weight of intumescent material per 1000 parts by weight of rubber solution was applied to four steel sections. The formulation was applied to the shot blasted surface of the steel sections by means of a brush. A total of three coats were applied over 14 days, thereby allowing time for each coat to dry before the subsequent coat was applied. The sample was air cured for 21 days after the final coating was applied. The coating thickness was measured using a digital Elcometer type 345 at a mean thickness of 1.27mm with a standard deviation of 0.31 on a total of 40 measurements. The measurements were random measurements on all four sections.

ExgjLaple 4 - Testing the fire resistance of the coated steel sections of Ex"le 3.

A plurality of type K thermocouple (mineral insulated) were located in the steel section of the four test sections by drilling a hole in the section and inserting the thermocouple.

The coated steel sections of Example 3 were loaded into a 1.3m x 1.3m x 1.Om gas fired furnace. The sections (1,2) were arranged in a cylinder of square cross-section, as illustrated in Figure 1. The base of the furnace was built to a height which restricted any direct impingement on the test sample 1 -20from the burner flame. The steel sections were also insulated at the base and top using rockwool slabs (4,5).

1 Further type K thermocouples (mineral insulated) were located in the furnace to measure the temperature profile of the kiln. Location of the kiln thermocouples were as follows: 1. Oven roof. 2.Front of kiln, top left. 10 3.Back of kiln, top right. 4.Front of kiln, top right. S.Back of kiln, top left. 6. Adjacent td section base. 7.Adjacent to section base. 15 8. On face (2) (indicated by arrow A on Figure 1). 9. On face (1) (indicated by arrow B on Figure 1). 10.On face (3) (indicated by arrow C on Figure 1). The section was fired in accordance with the requirements of BS476:Part 20: 20 1987.

X TEST RESULTS TIME Thermo- Thermo- Thermo- Thermo- Thermo,- ThermoThermo- Thermo- Thermo- Thermo couple couple couple couple couple couple couple couple couple couple No. I No.2 No.3 No.4 No.5 No.6 No.7 No.8 No.9 No. 10 0 20 18 17.7 17.8 17.9 17.8 17.7 16.1 16.3 16.1 1 349 420.3 265.8 280.3 354.1 277 329.7 21.8 21.5 22.8 2 445 581.4 491.7 518.4 553.3 499.1 488.9 51.2 59.4 56.7 3 502 605.6 527.2 546.4 580.7 525.9 514.9 87.8 93.9 92.3 4 544 631.7 555.8 576 608.8 552.7 541.9 123.3 126.9 126.8 576 640.7565.7 584.7 619.6 562.8 555.8 151.3 153.7 154.3 6 603 666.2 588.2 604.9 639.9 575 563.2 180 180 181.5 7 626 678 603 624.3 655.5 590.5 581.5 204.9 204.9 206.1 8 645 683.2 615.7 634.6 662.9 599.4 594.3 227.4 226.8 228.8 9 663 700 636.9 650.8 -681.1 625.7 619.2 245.2. 245.8 248 678 710.2 649.9 666.3 693.8 640.5 633.6 259.2 261.4 264.2 11 693 719.9 664.5 678.1 702.4 653.7 649.1 270.5 274.7 277.5 12 705 734 680.2 692.5 716 671.5 666.6 280.6 286.4 289.4 13 717 739.8 688.4 702.6 722.6 681.9 677.6 290.3 297 300.9 14 728 752.1 697.9 711 734 688.1 690.1 299.8 307.3 312 739 749.6 707.4 726.1 737.7 697.3 697 309.4 317.3 321.6 16 748 767.8 717.9 732.2 753.8 709.3 712.6 318.9 327 331.5 17 757 776.1 727 745.3 761.9 715.5 722.3 328.1 336.4 340.6 18 766 785 738.8 753.3 770.8 727.2 735.4 337 405.2 349.8 19 774 779.3 742.2 757.7 769.5 730.3 737.3 345 518.3 358.8 781 792.2 748.7 768.2 779 734.8 746 352.7 566.1 368.2 21 789 805.6 759.7 776.1 793.8 746.7 760.8 360 - 595.9 377.8 22 796 813.4 768.1 782.4 803 753.6 770.9 365.9 483.4 389.1 23 802 815 777.7 791.5 804.6 763.4 777.9 371.4 521.3 397.5 24 809 823.6 777.6 794.2 811 764.2 784.4 377.3 436.1 409.2 815 830.6 790 806.4 819 776.2 797.6 383.1 515.7 419.3 26 820 831.3 793.2 814.1 819.6 784.4 800.1 389.9 627.5 428.4 27 826 845.9 809.4 820.7 833.3 795 813.2 397.3 683.3 437.6 28 832 842.2 804.1 820 830.1 791.9 812.3 405.1 713.4 444.7 29 837 854.5 816.1 833.1 842.7 811 823.7 412.6 720.8 452.9 842 857.6 820 830.5 846.4 813.2 828.3 420.1 717.5 461.3 847 865 828.2 837.2 854.5 821.6 836.8 428 718 469.3 32 851 875.2 832.8 839.3 861.9 825.7 844.2 436 722.6 477.7 33 856 885 835.6 840.3 -872.1 830 851.1 444.6- 772.8 486 34 860 891.7 841.8 849.4 878.8 836 859.1 452.9 725.8 494.6 865 878.9 833.8 838.4 868.8 827.2 852.2 461.3 486.9 503.6 36 869 846 823 825.8 843.6 815.9 837.5 469.8 495.5 511.6 37 873 872.4 836.6 842 864.8 829.7 852.3 478.6 504.7 520.7 38 877 858.8 836.8 838.6 856.2 828.3 850.2 486.8 514.5 528.6 39 881 871.9 845.1 848 867.9 838.5 860.7 495.2 523.8 537.3 885 878.4 852.7 856.1 875.5 845 86,6.4 503.5 533 546 41 888 877 854.1 856.6 874.4 847.2 867 511.3 542.3 555 42 892 881.9 857.9 860.7 879.2 850.8 872.1 519.2 551.6 563.5 896 893.5 868.2 869.7 890.2 860.2 881 527.1 560.9 572.3 44 899 915.1 878.4 883.1 907.1 872.4 895 534.9 569.9 580.9 902 908.9 873.7 877.2 - 901.9 868.3 888.8 542.5 578.1 589.6 1 46 906 895.6 873.3 873.1 893.7 866.7 886.6 550 587.5 597 -26Conclusion

The post test study revealed an error with thermocouple 9.

A coating ofthe test sample to a nominal thickness of 1.27mm on a steel section gave a fire protection of 40 minutes before the steel reached a temperature of 5501C. The coating had swelled to a thickness of 50mm. There were no indications of slumping or of the coating falling off the steel sections.

The test shows that the fire resistant formulation provides the required fire protection.

27

Claims (27)

1. A fire resistant formulation comprising a first polymeric material and an intumescent formulation, wherein said first polymeric material has a Young's S Modulus of less than 5OGNm or is vulcanisable to have a Young's Modulus of less than 50GNM-2.

2. A formulation according to claim 1, wherein said Young's Modulus is less than SGNm-'.

3. A formulation according to claim 1 or claim 2, wherein the elastic limit of the first polymeric material is at least SMNm -2.

4. A formulation according to any preceding claim, wherein said first is polymeric material is a rubber.

5. A formulation according to any preceding claim, wherein said intumescent formulation comprises a first component comprising a phosphate material having at least 10 wt% phosphorous.

6. A formulation according to claim 5, wherein said first component is a phosphate polymer.

7. A formulation according to claim 5 or claim 6, wherein said phosphate 25 material of the first component is encapsulated by a polymer resin.

8. A formulation according to claim 7, wherein encapsulation means is arranged to produce non-flammable gases when degraded by heat andlor a flame and do not produce oxygen gas on degradation.

28

9. A formulation according to any of claims 5 to 8, wherein the first component comprises 13wt% to 50wt% phosphorous and 5wt% to 40wt% nitrogen.

10. A formulation according to any preceding claim, wherein said intumescent formulation comprises a second component comprising a blowing agent which produces a gas when heated and/or burned.

11. A formulation according to claim 10, wherein said second component comprises 50wt% to 90wt% nitrogen and 15wt% to 80wt% carbon.

12. A formulation according to claim 10 or claim 11, wherein said second component comprises only carbon, nitrogen and hydrogen atoms.

is

13. A formulation according to any of claims 10 to 12, wherein said second component is a melamine.

14. A formulation according to any preceding claim, wherein said intumescent formulation comprises a third component which promotes production of a stable and carbonaceous char when the fire resistant formulation is heated and/or burned.

15. A formulation according to claim 14, wherein the third component is a 25 polyhydric alcohol.

16. A fire resistant formulation comprising a first polymeric material and an intumescent formulation, wherein said first polymeric material is a rubber.

29

17. A fire resistant formulation comprising a first polymeric material, for example selected from the group comprising PVC, polyurethane, polyester and phenolic-resins, and an intumescent formulation.

S

18. An intumescent formulation comprising first, second and third components, wherein said first component comprises a phosphate material having at least lOwt% phosphorous, said second component comprises a blowing agent and said third component comprises a carbon source.

19. A substrate coated with a fire resistant formulation, wherein said fire resistant formulation comprises a polymer and an intumescent formulation which polymer has a Young's Modulus of less than 50GNm.

20. A substrate according to claim 19, wherein said fire resistant formulation is is arranged to expand by at least 100% when subjected to heating and/or burning.

21. A method of manufacturing a fire resistant material, wherein a surface of a substrate is coated with a fire resistant formulation to provide a fire resistant 20 material, said fire resistant formulation comprising a polymer and an intumescent formulation, said polymer having a Young's Modulus of less than 50GNM-2.

22. An invention according to any of claims 19 to 21, wherein said substrate 25 is a metal substrate.

23. An invention according to any of claims 19 to 22, wherein said substrate is in the form of a structural element used in construction.

24. A fire resistant formulation substantially as hereinbefore described with, reference to the Examples.

25. An intumescent formulation substantially as hereinbefore described with 5 reference to the Examples.

26. A substrate substantially as hereinbefore described with reference to the Examples.

27. A method substantially as hereinbefore described with reference to the Examples.