GB2521383A

GB2521383A - Fire retardant composition

Info

Publication number: GB2521383A
Application number: GB1322356.5A
Authority: GB
Inventors: Ehab Rida Mahmoud Habib
Original assignee: AL HAJAM ESTABLISHMENT VOLUME TRADING
Current assignee: AL HAJAM ESTABLISHMENT VOLUME TRADING
Priority date: 2013-12-18
Filing date: 2013-12-18
Publication date: 2015-06-24
Also published as: SA516371361B1; WO2015092410A1; GB201322356D0

Abstract

A composition comprises monoethylene glycol, hydrogen borate, monoammonium phosphate and water for use as a fire retardant and may be a solution or a gel. Also shown is a method of preparing said composition and a method of using said composition as a fire retardant, a method of imparting fire resistance to a substrate by applying said composition and to a fire resistant substrate. The substrate may be cellulose based e.g. paper, wood or a sponge, foam or fabric e.g. cotton, wool.

Description

Fire Retardant Composition

Field of the invention

The present invention relates to a composition comprising monoethylene glycol, hydrogen borate, monoammonium phosphate and water for use as a fire retardant.

The present invention also relates to a method of preparing said composition and a method of using said composition as a fire retardant. The present invention further relates to a method of imparting fire resistance to a substrate by applying said io composition and to a fire resistant substrate.

Background of the invention

Residential and commercial fires annually claim the lives of hundreds of people and i cause damage to property. As a result attention has focused on methods of eliminating or reducing the risk of fire by substituting combustible materials with fire resistant materials whenever possible. One approach is to treat combustible materials with a fire retardant composition, thereby rendering them less susceptible to burning. A number of such fire retardant compositions are known.

For example, US4514327 discloses a fire retardant composition for wood and fabric products, comprising ammonium sulfate, borax, boric acid, monoammonium phosphate and water. EP0146122 discloses a fire retardant composition for cellulosic substrates, comprising boric acid, an alkali metal borate, ammonium phosphate and water. US5405555 discloses a fire retardant composition for ceflulosic materials, comprising ammonium sulfate, borax, boric acid, hydrogen peroxide, water and optionally a surfactant and/or an alkyl phthalate ester. US5151127 discloses a composition which preserves or protects wood and cellulose products against detei-ioration due to mould, fungi, insects, weather, fire and flames. The composition comprises boric acid, a water-based acrylic resin, water and optionafly borax, urea, magnesium chloride, ammonium polyphosphate, ammonium thiosulfate and triethylamine. US4725382 discloses a fire retardant composition for wood products, comprising boric acid, diammonium phosphate, monoammonium phosphate and water. W0o2/1o2926 discloses a fire retardant composition for wood-based panels, comprising a tertiary amine, boric acid or a borate, a phosphate and water.

However, the known fire retardant compositions have various disadvantages. For example, many fire retardant compositions are detrimental to the physical or mechanical properties of the substrate to which they are applied, for example causing the substrate to loose strength. Often the fire retardant compositions leave an unsightly deposit or residue on the substrate making it less aestheticafly attractive.

Moreover many fire retardant compositions are acidic and/or corrosive and/or hazardous to humans, which makes them unsafe to handle and limits their

applicability.

jo Another problem is the environmental safety of the fire retardant compositions. Many fire retardant compositions comprise halogenated compounds, which are not only unsafe to handle, but can also emit toxic gases in the presence of fire. Toxic gases are frequently more dangerous to humans than the fire itself. Consequently, not only should the fire retardant compositions reduce substantially the flammability of the substrate, but they should also be safe to humans during flaming conditions.

Tt would therefore be desirable to have a fire retardant composition which does not suffer from the disadvantages of the prior art compositions. The present invention provides an improved fire retardant composition.

It is an object of the present invention to provide a composition which is halogen-free, non-acidic, non-corrosive, eco-friendly, non-hazardous and/or non-toxic. It is another object of the present invention to provide a composition which has good mechanical properties, for example, it is easy to apply, it penetrates a substrate well, it is easily absorbed by a substrate, and/or it has a good weathering performance. It is also an object of the present invention to provide a composition which renders a substrate fire resistant in the sense that the substrate burns less or more slow'y or with less heat or in the sense that the substrate emits less toxic gas during burning. It is an object of the present invention to provide a composition which imparts this fire resistance without negatively affecting the physical or mechanical properties of the substrate.

Summary of the invention

As used herein throughout the specification and claims, the term "fire retardant" composition refers to a composition which, when applied to a substrate, renders the substrate fire resistant. The term "fire resistant" substrate refers to a substrate which, when it is snbjected to a flame or fire, burns less or more s1owy or with less heat or emits less toxic gas, compared to the same substrate to which the composition has not been applied. In other words, a "fire resistant" snbstrate is less susceptible to burning and/or tess likely to emit toxic gas when it does burn, compared to the same substrate to which the composition has not been applied.

A first aspect of the present invention provides a composition comprising monoethylene glycol, hydrogen borate, monoammonium phosphate and water. The composition is preferably a fire retardant composition.

Preferably the composition isa solution or a geL If the composition is a gel, it preferably further comprises a gelling agent such as carboxymethyl cellulose.

Tf the composition is a solution, it preferably comprises or consists essentially of or consists of: (a) 1-20% by weight monoethylene glycol, (b) 1-30% by weight hydrogen borate, (c) 8-40% by weight monoammonium phosphate, and (d) 35-90% by weight water.

More preferably, if the composition is a solution, it comprises or consists essentially of or consists of: (a) 2-15% by weight monoethylene glycol, (b) 2-25% by weight hydrogen borate, (c) 10-40% by weight monoammonium phosphate, and (d) 35-85% by weight water.

Preferably the composition does not comprise any halogenated compounds.

Preferably the composition has a pH of about 4-7.

Preferably the composition is suitable for nse as a fire retardant.

A second aspect of the present invention provides a method of preparing a composition according to the first aspect of the present invention, wherein the method comprises mixing monoethylene glycol, hydrogen borate, monoammonium phosphate and water in any order.

Preferably the monoethylene glycol, hydrogen borate, monoammonium phosphate and water are mixed to form a solution or a gel.

Preferably the method is carried out at room temperature. Optionally the reaction o mixture may be heated tip to 50°C.

Preferably the method comprises the steps of: (a) dissolving hydrogen borate in water, (b) adding monoammonium phosphate to the solution obtained in step (a), and (c) adding monoethylene glycol to the solution obtained in step (b).

A third aspect of the present invention provides a method of using a composition according to the first aspect of the present invention as a fire retardant, the method comprising the step of applying the composition to a substrate.

The third aspect of the present invention also provides a method of imparting fire resistance to a substrate, the method comprising the step of applying a composition according to the first aspect of the present invention to the substrate.

Preferably the treated substrate has a substrate: composition weight ratio of from i: to 15o:1 after drying, preferably from 1:1 to 100:1, preferably from 1:1 to 8o:i.

Preferably the composition is applied to the substrate in order to render it less susceptible to burning and/or less likely to emit toxic gas when it does burn.

Preferably the substrate is a cellulose based substrate (such as paper, carton, timber, wood, MDF, HDF or laminated flooring), a sponge, a foam or a fabric (such as cotton, The composition may be applied to the substrate by any suitable method, including but not limited to dipping, soaking, coating, spraying, brushing, rolling, pouring, immersing, submerging, impregnating or pressure impregnating. Preferably the composition is applied to the substrate, followed by drying the substrate.

A fourth aspect of the present invention provides a substrate to which a composition according to the first aspect of the present invention has been applied.

Preferably the substrate is a cellulose based substrate (such as paper, carton, timber, wood, MDF, HDF or laminated flooring), a sponge, a foam or a fabric (such as cotton, The composition may be appfled to the substrate by any suitable method, including but not limited to dipping, soaking, coating, spraying, brushing, roBing, pouring, immersing, submerging, impregnating or pressure impregnating. Preferably the composition is applied to the substrate, followed by drying the substrate.

Preferably applying the composition to the substrate has rendered the substrate less susceptible to burning and/or less likely to emit toxic gas when it does burn. Preferably when the substrate is subjected to fire, the substrate burns less or more slowly or with less heat or emits less toxic gas, compared to the same substrate to which the composition has not been applied.

Detailed description of the invention

The composition of the present invention comprises monoethylene glycol (HOCH2CH2OH), hydrogen borate (H3B03), monoammonium phosphate (NH4 H2P04) and water. Without wishing to be bound by theory, it is believed that when a substrate treated with a composition according to the present invention, is subjected to a flame or fire, the monoammonium phosphate reduces the amount of oxygen on the surface of the substrate and prevents oxygen from penetrating the substrate, such that the substrate only carbonizes but does not burn. The high heat resistance of hydrogen borate is believed to slow down heat transfer and to delay the substrate from reaching burning temperature. Hydrogen borate is also believed to increase the heat resistance of substrates and to suspend water molecules in cellulose based substrates. It is further believed that the presence of the monoethylene glycol in the composition of the present invention provides the composition with its good mechanical properties and weathering performance.

Example 1

Hydrogen borate (300g) was dissolved in water (io,oooml) with stirring. Then monoammonium phosphate (2,000g) was added to the solution under stirring. Finally monoethylene glycol (300ml) was added to the solution under stirring to obtain a final solution. The process was carried out at room temperature.

Example 2

Hydrogen borate (200g) was dissolved in water (500ml) with stirring. Then monoammonium phosphate (200g) was added to the solution under stirring. Finally monoethylene glycol (9oml) was added to the solution under stirring to obtain a final solution. The process was carried out at room temperature.

Example

An ecru woven fabric (80% cotton) was dipped into the solution obtained in example 1.

1kg of fabric absorbed about oog of the solution of example 1. The fabric was dried at room temperature for 24 hours. Then the fabric was subjected to a naked flame. The emitted gas was tested for the presence of tris(2,3-dibromopropyl) phosphate (TRIS), polybrominated biphenyl (PBB), tris(i-aziridinyl) phosphine oxide (TEPA), pentabromo diphenyl ether (pentaBDE), octabromo diphenyl ether (octaBDE), hexabromocylcododecane (HBCDD), decabromo diphenyl ether (decaBDE), tris(2-chloroethyl) phosphate (TCEP) and short-chained chlorinated paraffins (Clo-C13).

None of these compounds were detected (detection limit 5ppm).

Example 4

Oak was dipped into the solution obtained in example 1 for 12 hours. oog of oak absorbed about 75 of the solution of example 1. The oak was dried at room temperature for 24 hours. Then treated and untreated oak samples were subjected to a burning test using a gas-fired radiant heat panel with pilot flame ignition. The results of this burning test are summarised in Table 1.

Parameter Unireated oak Treated oak (average of 3 specimens) (average of 3 specimens) Critical flux at 6.74 18.20 extinguislunent, CFE (kW/m2) Heat for sustained burning, o.8i 4.70 Q (MJ/ni) Total heat release, Qt (MJ) 0.48 0.38 Peak heat release, qp (kW) 1.94 1.37 Burning droplets no no

Table 1

ExamT5le 5 Fabric (80% cotton) was dipped into the solution obtained in example 1. 1kg of fabric absorbed about 2oog of the solution of example 1. The fabric was dried at room temperature for 24 hours. Then treated and untreated fabric samples were subjected to a burning test using a gas-fired radiant heat panel with pilot flame ignition. The resuks of this burning test are summarised in TaNe 2.

Parameter Untreated fabric Treated fabric (average of 3 specimens) (average of specimens) Critical flux at 2.86 12.36 extinguishment, CFE (kW/m2) Heat for sustained burning, 0.91 0.61 Qst, (M,J/n12) Total heat release, Qt (MJ) o.o8 0.07 Peak heat release, q1 (kW) 1.51 1.37 Burning droplets no iio

Table 2

Examule 6 i Oak was dipped into the sohition obtained in example 1 for 12 hours. oog of oak absorbed about of the solution of example 1. The oak was dried at room temperature for 24 hours. Then the treated oak was tested according to BS 476 Part 7 "Surface spread of flames". The treated oak was dassified as class 2.

ExamDle 7 A composite of upholstery foam and fabric (80% cotton) was dipped into the s&ution obtained in example 1. The composite was dried at room temperature for 24 hours.

Then treated and untreated composite samples were tested according to BS 5852 Crib 5 Test. The weight of the tested composites (after drying) is summarised in TaNe 3. The o untreated composite failed the test, the treated composite passed the test.

Parameter Untreated composite Treated composite Size(mmxmm) 300X450 450X450 300X450 450X450 Weight (g) 244.58 348.80 346.37 591.74

Table 3

Example 8

Fabric (8o% cotton) was dipped into the solution obtained in example 1. 1kg of fabric absorbed about oog of the solution of examp'e 1. The fabric was dried at room temperature for 24 hours. Then treated and untreated fabric samples were tested according to BS 5438: 1989 Test 2A "Limited flame spread: face ignition". The results of this test are summarised in Table 4.

Parameter Untreated fabric Treated fabric (average of 3 specimens) (average of 3 specimens) Flame application time 10 seconds in 10 seconds in 10 seconds in 10 seconds in warp direction weft direction warp direction weft direction Duration of flaming after 79.7 64.7 73.3 114.7 removal of ignition source (sec) ________________ ________________ ________________ ________________ Duration of afterglow (sec) N/A N/A N/A No Cowing reaches upper N/A N/A No No edge or one of vertical edges ________________ ________________ ________________ ________________ Occurrence of any flaming Yes Yes No Yes debris

Table 4

Parameter Untreated fabric Treated fabric (average of 3 specimens) (average of 3 specimens) Flame reaches upper edge Yes Yes Yes Yes Flame reaches vertical Yes Yes Yes Yes edge ________________ ________________ ________________ ________________ Hole develops which Yes Yes Yes Yes extends to upper edge or one of vertical edges ________________ ________________ ________________ ________________ Maximum extent of ally iôo i6o iôo iôo hole in horizontal direction (nuii) Maximum extent of ally 200 200 200 200 hok in vertical direction (mm) Maximum damaged length 200 200 200 200 (ignoring any surface effects such as scorching or smoke deposition)

Table 4 (cont)

Example g

Oak was dipped into the solution obtained in example 1 for 12 hours. 2oog of oak absorbed about 75 of the solution of example 1. The oak was dried at room temperature for 24 hours. Upholsteiy foam was dipped into the solution obtained in example 1. oog of foam absorbed about oog of the solution of example 1. The foam o was dried at room temperature for 24 hours. Corrugated cardboard was sprayed with the solution obtained in example 1. l5og of cardboard absorbed about log of the solution of example 1. The cardboard was dried at room temperature for 24 hours.

Then the treated and untreated materials were tested according to TS EN 60695-11-10 (Fire hazard testing -Part n-b: Test flames -oW horizontal and vertical flame test methods). The results of this test are summarised in Table 5. -10-

Material Vertical burning Horizontal burning classification classification (average of 5 specimens) (average of 3 specimens) Untreated oak None not tested Untreated cardboard V-2 not tested Untreated foam ignited immediately and melted and iited immediately and melted and burned completely within a few burned completely within a few seconds sends Treated oak V-o not tested Treated cardboard V-i not tested Treated foam None HB40

Table 5

The treated and untreated materials were also tested according to DIN 4102-i (Fire behaviour of building materials and elements -Classification of building materials -Requirements and testing -Subclause 6.2 Class B2 Materials). The results of the edge ignition test are summarised in Table 6 and the results of the surface ignition test are summarised in Table 7.

Observation Untreated Untreated Untreated Treated Treated Treated oak cardboard foam oak cardboard foam Numberof 5 5 5 0 0 0 specimens flamed Numberof 0 0 0 5 5 5 specimens not flamed Span time -15-25 <5 --- (sec) ________________ ________________ ________________ ________________ ________________ ________________ Did molten no yes yes no no no dripping occur? Did filter no yes yes no no no paper get flamed?

Table 6

-11 -Observation Untreated Untreated Untreated Treated Treated Treated oak cardboard foam oak cardboard foam Numberof 5 5 5 0 0 0 specimens flamed Numberof 0 0 0 5 5 5 specimens not flanwd Span time -15-25 <5 --- (see) ______________ _______________ _______________ ______________ _______________ _______________ Did molten no no yes no no no dripping occur? Did filter no no yes no no no paper get flamed?

Table 7

The results shown in Tables 6 and 7 indicate that the DIN 4102-1 fire classes of the untreated materials are B2 or worse and that treatment with the composition of the present invention improved their fire classes to better than B2.

The tests according to TS EN 60695-11-10 and DTN 4102-1 both showed that application of the composition of the present invention improved the resistance of all io three materia's to ignition and flame spread.

Tt will be understood that the present invention has been described above by way of examp'e only. The examples are not intended to Umit the scope of the invention.

Various modifications and embodiments can be made without depardng from the scope i and spirit of the invention, which is defined by the following claims on'y.