WO2020055295A1

WO2020055295A1 - Aflame retardant composition comprising the salts ammonium sulpha, and disodium hydrogen phosphate, and a softener

Info

Publication number: WO2020055295A1
Application number: PCT/SE2019/000013
Authority: WO
Inventors: Mats Svensson
Original assignee: Mats Svensson
Priority date: 2018-09-10
Filing date: 2019-09-10
Publication date: 2020-03-19
Also published as: EP3850063A1; EP3850063A4; AU2019338080A1; ZA202104775B

Abstract

The invention regards an ecological flame retardant composition adapted to protect materials that are flammable, a method to prepare it. No bromine, or borax components are included in the composition. Its composition comprises at least one of a mixture of a predetermined amount of the salts ammonium sulpha, disodium hydrogen, and a softener phosphate and a mixture of a predetermined amount of water including a predetermined amount of the salts ammonium sulpha, disodium hydrogen phosphate and a softener.

Description

AFLAME RETARDANT COMPOSITION COMPRISING THE SALTS AMMONIUM SULPHA, AND DISODIUM HYDROGEN PHOSPHATE, AND A SOFTENER

Technical field

The present invention pertains to an ecological flame retardant composition adapted to protect materials that are flammable, and a method therefore.

Background art

The current market for flame retardants is since many years dominated by products containing different bromine compositions. Bromine is one of the most toxic existing halogens very damageable to human beings and to the environment. Inter alia flame

retardant products with bromides contain dioxins, which on a long time basis can mutate the genome (DNA) of human beings.

Since flame retardants containing bromide make that much damage a debate is on the agenda in large parts of the world. The European Union has decided that flame retardants containing bromides are to be phased out at the latest in the year 2012 to be replaced by products that are environment friendly. In Sweden alone there exist about 70 brands of flame retardants containing bromide, which all eventually will be forbidden.

Moreover, the company Apple ® is said to stop utilizing bromides at the latest in the year 2012.

Studies at the hospital’’Rigshospitalet” in Copenhagen revealed a correlation of deformations on boys genitals regarding the utilization of flame retardants.

At the Karolinska Institute in Stockholm-Solna, research has revealed a correlation between bromide and brain damages on adults and children.

Therefore there has been a long felt need for an environment friendly alternative to toxic flame retardants.

The patent document GB 2165270 A describes a flame retardant containing bromides.

Another flame retardant ingredient is compositions/compounds of borax such as boric acid, which are expensive and there is a shortage of them. Moreover, there exists a concern that borax is more toxic then what has yet been recognized. Local city authorities do not like the use of borax in flame retardant, because sooner or later it will end up in the sewers where borax can react with other chemicals.

Hence, there is an incentive to replace borax compositions from flame retardants, which are pointed out in the paper to Day, M and Wiles, D.M;” Combustibility of loose fiber fill cellulose insulation II. The role of a third chemical component in a borax: boric acid system”; Journal of Consumer Product Flammability, (Marc 1979), Vol. 6, pages 20-27. This paper discloses salts like sodium phosphate tribasic and ammonium sulphate in a mixture with borax and boric acid as a flame retardant. But the paper only discloses a partly replacement of borax compositions, but not an entire replacement of them. Furthermore, it refers to the paper“E. V. Anderson, Boric Acid Future in Insulation Uncertain. Chem. and Eng. News 56, (15) 11 (1978).".

Summary of the invention

The present invention regards a flame retardant composition which does not contain bromide or borax compositions/compounds, but only the salts ammonium sulpha, disodium hydrogen phosphate, and a softener, thus avoiding problems mentioned above. It is an improvement of the patent US 8,246, 864 B2 to Svensson.

Hence, the present invention sets forth an ecological flame retardant composition adapted to protect materials, which are flammable, it comprises:

the salts ammonium sulpha and disodium hydrogen phosphate, with a softener added to it.

In another embodiment of the present invention, the composition contains a 4 % solution of each of the salts ammonium sulpha, disodium hydrogen phosphate, which protects staining of materials, and not leaving any odour.

A further embodiment comprises that said mixture of the salts, ammonium sulpha and disodium hydrogen phosphate constitutes a solid composition.

Still a further embodiment comprises that a softener is added, in a fluid composition with the salts.

Yet another embodiment comprises that said salts and softener are mixed in water.

Yet one embodiment comprises that the softener is vinegar.

One embodiment of the present invention sets forth a method to prepare an ecological flame retardant composition adapted to protect materials that are flammable, whereby the salts ammonium sulpha and disodium hydrogen phosphate, are mixed with a softener.

It is appreciated that the attached method sub claims adhere to the sub claims of the actual composition.

Brief description of the drawings

Henceforth reference is had to the attached drawings in the accompanying text of the description for a better understanding of the present invention with its embodiments and given examples, wherein:

Fig. 1 schematically illustrates a prior art cone calorimeter utilized to test specimens treated with the flame retardant of the present invention by controlled levels of radiant heating;

Fig. 2 depicts a prior art graph of heat release rate for samples A to C applying the flame retardant according to the present invention on the samples; Fig. 3 depicts a prior art graph of heat release rate for sample D applying the flame retardant according to the present invention on the sample;

Fig. 4 depicts a prior art graph of smoke production rate for samples A to C applying the flame retardant according to the present invention on the samples; and

Fig. 5 depicts a prior art graph of smoke production rate for sample D applying the flame retardant according to the present invention on the sample.

Tables

The following prior art tables are referred to throughout the present description: Table 1 depicts materials that were tested for heat release and smoke production;

Table 2 depicts measures recorded during tests on the materials in Table 1 ; Table 3 depicts further test results on the materials in Table 1 ;

Table 4 depicts test results on flame retardant treated cotton cloth; and

Table 5 depicts test results on cotton cloth, which was not treated with a flame retardant.

The tables are found at the end of the description.

Word list

In conjunction with the Tables a word list is attached, which explains the abbreviations and variables utilized in the tables.

Detailed description of preferred embodiments

The present invention is related to a flame retardant composition which does not contain bromide or borax compositions/compounds, but only the salts ammonium sulpha, disodium hydrogen phosphate, and a softener is added to the salts mentioned to as in one preferred softening of fabrics. It can also be utilized as a solid composition or as a powder.

Furthermore, the present invention is an improvement of the patent US 8,246, 864 B2 to Svensson.

The present invention salts are added a softener, and a mixture of the salts mentioned are in one embodiment of the present invention that the concentration of the salts are each one 4% in a solution of the flame retardant solution in for instance water.

Moreover, the present invention sets forth an ecological flame retardant composition adapted to protect materials, which are flammable, it comprises:

In another embodiment of the present invention, the composition contains a 4 % solution of each of the salts ammonium sulpha, disodium hydrogen phosphate, which protects staining of materials, and not leaving any odour. A further embodiment comprises that said mixture of the salts, ammonium sulpha and disodium hydrogen phosphate constitutes a solid composition.

Yet one embodiment comprises that the softener is vinegar.

After consulting a company which improves for instance chemical solutions/compounds, toxikon.com they derived that the optimal composition for a preferred embodiment of a water based composition of the salts ammonium sulpha to 4% in the solution and disodium hydrogen phosphate to 4%.

A preferred embodiment of a mixture of the salts with a softener is an example where 12 dl is mixed with 3 di 24% vinegar, and 9 dl of boiled water to be cooled. Thereafter an etheric oil as for instance Lavender is added to it, and the mixture is shaken before use for instance as it is contained in a bottle or the like. The softener shall not include phthalates, making the entire mixture of the salt, and softener environ friendly. For instance softeners utilized for clothes in washing machines include Phthalates, which can cause cancer.

Other concentrations of the mixture are possible, and not ruled out in the present invention.

In another preferred prior art embodiment, when the flame retardant of the present invention is in a solid state and/or in a powder/granular form, the amount of ammonium sulpha is between 40 to 60 % and the amount of disodium hydrogen phosphate 40 to 60 %, to make up 100 % when mixed to a composition. It is soluble in water to a maximum of 7.6% at 20 °C, and its decomposition temperature is between 240-280 °C.

Hence, it has also been determined that the Ammonium Sulfate Special Grade, production No.: 30042199 produced by BASF Antwerpen NV is especially suitable for the composition described herein. As well as the chemical product Disodium Phosphate 12 Hydrate, Disodium Monohydrogenmonophosphate, produced by the company, Chemische Fabrik Budenheim KG, Germany. The aqueous solution of Disodium Phosphate has an alkaline action. When Disodium Phosphate is heated Tetrasodium Pyrophosphate is formed. It reacts with heavy metal salts to give Phosphates of solubility. In addition Disodium Phosphate has excellent buffering qualities. Due to its physical properties, melting point appr. 35 °C, Disodium Phosphate 12-Hydrate tends to form lumps.

The salts utilized in the present invention must not stain materials or leave any odour in accordance with the salts from the companies mentioned above.

The objective of a flame retardant is to prevent and/or delay the upcoming of a fire. A flame retardant should be able to prevent the upcoming of fire in 12 to 15 min. Utilized conventional flame retardants are the so called bromide flame retardants. Bromide flame retardants are currently one of the most damageable to the environment, and in longer terms can cause mutations of a person’s DNA.

Every day approximately 550000 persons perish in fires all over the world. This is the fourth most common cause to accidents. Hence, the demand on taking fire preventive measures increase and the industry is under pressure to change to environmental fire protections.

The present invention flame retardant is very environment friendly. It is even possible to drink, as it is based on two salts, ammonium sulpha and disodium hydrogen phosphate as well as a softener, such as vinegar, that are classified as food.

A large number of tests on the present invention salts as flame retardants have been administrated at the accredited laboratory, SP Technical Research Institute of Sweden ( Statens Provningsansatalt) in Boras Sweden. All the tests included testing booth fabrics and surface materials such as building materials with excellent results, which are further elaborated in the following description. One result of the test was that the flame retardant of the present invention fulfilled the Swedish regulations for building materials, which apply as guidelines for constructors when choosing building materials. The present invention flame retardant is non toxic, and thereby friendly to the environment.

When a material impregnated with the present invention flame retardant is heated a powerful reaction with the salts contained arises. A carbon layer is created, which suppresses the oxygen, and as is well known without oxygen no fire. Test on different materials such as paper tissues to fabrics showed that it is almost impossible to create fire on the materials treated with the present invention flame retardant.

SP has conducted multiple tests, which all ended with excellent results. The fabrics that were tested and had the flame retardant applied underwent six fire tests, i.a., according to tests under the regulations of SIS 65 00 82, and no fire arose which made SP classify the materials as hard to set on fire.

Other materials that underwent tests were wood, soft board, particle board, and plywood so called surface materials. Normally those materials should be pressure

impregnated with the flame retardant of the present invention for maximum resistance against fire. But those materials were only soaked during the tests at SP, and although passed the tests according to the Swedish building regulations.

Currently numerous test with the flame retardant are conducted on plastics. These tests are supposed to end in 2010, and will form a basis for the utilization of the flame retardant at global manufactures of plastics. In year 2007 104 persons perished during fires in Sweden, and approximately 1.5 schools a day are exposed to fire. Due to the current increased utilization of plastics, the time for a fire to start has decreased from 15 min. to 3 min. in the past fifty years.

In its powder/granular form the flame retardant of the present invention will be mixed with plastic materials during the manufacture of plastic items, thus being embedded in the plastic product manufactured to act as a flame retardant.

Fig. 1 schematically illustrates a cone calorimeter 10 utilized to test specimens treated with the flame retardant of the present invention by controlled levels of radiant heating at SP. Specimens or samples utilized during testing are depicted in the attached Table 1. With the cone calorimeter 10, ISO 5660-1 , the specimens of 0.1 by 0.1 m are exposed to controlled levels of radiant heating. The specimen surface is therefore heated up and an external spark ignitor16 ignites pyrolysis gases from the specimen. Gases are collected by a hood 20 an extracted by an exhaust fan 26.

The cone calorimeter itself is made up of a load cell 12, and a sample 14 is positioned on it. From the spark igniter 16 a cone heater 18 leads gases to the exhaust hood 20, and reference numeral 22 indicates were gas samples are taken. The calorimeter has a laser extinction beam 24 including temperature measurements, and at 28 temperature and differential pressure measurements are taken.

Heat release rate (HRR) is determined by measurements of the oxygen consumption derived from the oxygen concentration and the flow rate in the exhaust duct. As mentioned the specimen 14 is placed on the load cell 12 during testing. A retainer flame covers the periphery of the specimen 14, and smoke rate is measured by the laser system 24.

Now with reference to Table 2 only one test on each material, soft board (sample A), Article board, light (sample B), plywood (sample C), and particle board, dark (D), were carried out, instead of the three stipulated in the standard. It can thus not be used as the sole basis for a classification or an approval. A ConeTools (software) simulation is not part of the accreditation referred to.

All products were tested with an irradiance of 35 kW/m². The simulation software ConeTools indicates the classification according to EN 13501 -1 based on ISO 5660 test results. In Table 2 a summary of the test results are given including the FIGRA value and classification. It should be noted that the final classification according to EN 13501 -1 is based also on smoke production and burning droplets/debris, which is not taken to account by ConeTools.

According to Swedish building regulations walls and ceiling surface materials in buildings of class Br2 and Br3 shall have properties C-s2, dO or D-s2, dO. In escape ways in buildings of class Br1 properties B-s1 , dO and C-s2, dO are asked for.

The test results in Table 3 were achieved in accordance with ISO 5660-1 : 2002 and ISO 5660-2:2002. The tested product was a water based flame retardant according to the present invention. All materials in Table 2 were soaked for 48 hours in the flame retardant, and the tests were performed with the test specifications irradiance level: 35 kW/m², calibration constant (C): 0.042221 m^1/2 g^1/2 K^1/2, orientation: horizontal, backing: no other than the non-combustible required in the standard, fastening: the product was loosely put on the backing, and note: a retainer frame was used. It should be noted that the symbol * indicates no ignition and the symbol ** no heat release data is given since the tested specimen did not ignite. Smoke production for sample specimen A and D is slightly under estimated due to a measurement error. See Fig. 4 and 5.

Fig. 2 depicts a graph of heat release rate for samples A to C applying the flame retardant according to the present invention on the samples specimen in a single test at irradiance 35 kW/m².

Fig. 3 depicts a graph of heat release rate for sample D applying the flame retardant according to the present invention on the sample specimen in a single test at irradiance 35 kW/m².

Fig. 4 depicts a graph of smoke production rate for samples A to C applying the flame retardant according to the present invention on the samples specimen in a single test at irradiance 35 kW/m².

Fig. 5 depicts a graph of smoke production rate for sample D applying the flame retardant according to the present invention on the sample specimen in a single test at irradiance 35 W/V/m².

In Table 4 is depicted how the flame retardant of the present invention reacts when cotton cloth was applied with the flame retardant through spraying. Non treated cotton cloth has a nominal area weight of 155 g/m² and the cotton cloth treated with the flame retardant has a nominal area weight of 175 g/m² (dry weight). According to Swedish rules, issued by The national Board of Housing, Building and Planning (Boverket), common advices 1993:2, the test with the worst result should be ignored when calculating an average value, thus test no. 3 was excluded when the average values were calculated. The test was performed with a specimen of approximately 0.4 mm and an area weight of approximately 175 g/m² at the conditions temperature (20 +5/-2) °C, and a relative humidity of (65 ± 2) %. It was not pre-treated with laundry or dry-cleaning prior to the test. Finally, cotton cloth that was not treated with the flame retardant of the present invention was tested, under the same conditions, and the result is depicted in Table 5. As it was not sprayed with flame retardant the weight of the cloth was 155 g/m2.

As can be seen when comparing the results of Table 4 and Table 5, the present invention flame retardant provides a very good flame protection without the use of bromine or borax compositions.

The present invention is not restricted to the examples and given embodiments presented above. A person skilled in the art is able to derive further possible embodiments by the attached set of claims.

Word list

Test results explanation - ISO 5660

Parameter Explanation

Test start The test specimen is subjected to the irradiance and the clock is started. tflasti Time from test start until flames with shorter duration than 1 s. tign Time from test start until sustained flaming with duration more than 10 s. "Text Time from test start until the flames have died out.

End of test Defined as the time when both, the product has been extinguished for 2 minutes, and the mass loss is less than 150 g/m² during 1 minute.

Ttest Test time. From test start until end of test.

9max Peak heat release rate during the entire test.

9180 Average heat release rate during 3 minutes from ignition. If the test is terminated before, the heat release rate is taken as 0 from the end of test.

9300 Average heat release rate during 5 minutes from ignition. If the test is terminated before, the heat release rate is taken as 0 from the end of test.

THR Total Heat Released from test start until end of test.

SPRmax Peak Smoke Production Rate from test start until end of test.

TSP Total Smoke Produced from test start until end of test.

MO Mass of specimen.

Ms Mass of specimen at sustained flaming.

Mf Mass of specimen at the end of the test.

MLR_jg_n-encj Mass Loss Rate. Average mass loss rate from ignition until end of test. MLR | o-9o Mass Loss Rate. Average mass loss rate between 10% and 90% of mass loss.

TML Total mass loss from ignition until end of test.

AH_C Effective heat of combustion calculated as the ratio between total energy released and total mass loss calculated from ignition until end of test.

SEA Specific Extinction Area defined as the ratio between total smoke released and total mass loss calculated from test start until end of test.

MARHE Maximum Average Rate of Heat Emission defined as the maximum of the function (cumulative heat release between t = 0 and time = t) divided by (time = t).

V Volume flow rate in exhaust duct. Average during the test. Table 1

Table 2

* NI = No ignition

Table 3

Test results

Name of

Property variable Sample A Sample B Sample C Sample D

Flashing (min:s) blush

Ignition (min:s) bgn NI* 01 :06 01 :27 02:37

All flaming ceased (minis) bxl 15:49 19:54 05:23

Test time (minis) best 10:00 17:49 21 :54 07:23

Heat release rate (kW/m²) q See figure 2 See figure 3

Peak heat release rate (kW/m²) q<nax 203 103 89

Average heat release, 3 min (kW/m²) quo

126 51 40

Average heat release, 5 min (kW/m²) q₃oo _* * 102 49 27

Total heat produced (MJ/m²) THR _* * 88.7 54.4 8.1

Smoke production rate (m²/m²s) SPR See figure 4 See figure 5

Peak smoke production (m²/m²s) SPR_max 0,8 1.6 0.4 1.0

Total smoke production over the nonflaming phase (m²/m²) TSP_no„_fl 21.1 12.7 34.7

Total smoke production over the flaming

phase (m²/m²) TSP„ 289 170 44

Total smoke production (m²/m²) TSP 310 183 79

Sample mass before test (g) M₀ 60.0 86.7 61.9 104.4

Sample mass at sustained flaming (g) M_s 85.7 59.3 99.5 Sample mass after test (g) M_r 37.2 18.6 13.0 83.1

Average mass loss rate (g/m²s) MLRi ign-end 7.5 4.3 6.4

Average mass loss rate (g/m²s) MLR|0-90 4.4 8.9 5.7 6.4

Total mass loss (g/m²) TML 7588 5233 1855

Effective heat of combustion (MJ/kg) AH_C

1 1.7 10.4 4.4 Specific smoke production (m²/kg) SEA 41 35 43

Max average rate of heat emission

(kW/m²) MARHE 1 1.5 96.0 52.8 23.1

Volume flow in exhaust duct (1/s) V 24 24 24 24

*NI = no ignition

** No heat release data is given since the specimen did not ignite.

Note

Smoke production for product A and D is slightly under-estimated due to a measurement error

Table 4

Test results

Test no 1 2 (3) 4 5 6 Average value of 5 tests

Direction † † (t) ®

After flame time, s 0 0 (0) 0 0 0 0

After glow time, s 0 0 (0) 0 0 0 0

Damaged length, mm 68 70 (79) 67 72 69 69

Burning drops No No (No) No No No

Table 5

Test results

Test no 1 2 3 4 5 6 Average value of 5 tests

Direction t † t ®

After flame time, s 17 - - 18

After glow time, s 0 - - 0

Damaged length, mm 300 - - 300

Burning drops No - - No

Claims

Claims:

1. An ecological flame-retardant composition adapted to protect materials, which are flammable, characterized in that it comprises:

the salts ammonium sulpha and disodium hydrogen phosphate, with a softener added to it, wherein the composition contains a 4 % solution each of said salts ammonium sulpha, disodium hydrogen phosphate, which protects a staining of materials, and not leaving any odour.

2. A flame retardant according to claim 1 , wherein said mixture of the salts, and ammonium sulpha and disodium hydrogen phosphate constitutes a solid composition.

3. A flame retardant according to claim 5, wherein said mixture includes, the salts ammonium sulpha, disodium hydrogen phosphate and a softener, constitutituting a fluid composition.

4. A method to prepare an ecological flame retardant composition adapted to protect materials that are flameable, characterized as comprising:

the salts ammonium sulpha and disodium hydrogen phosphate including 4% each of said salts ammonium sulpha, disodium hydrogen phosphate, with a softener added to it.

5. A method according to claim 5, wherein said mixture of the salts ammonium sulpha and disodium hydrogen phosphate constitute a solid composition in water.

6. A method according to claim 5method solution of the salts ammonium sulpha and disodium hydrogen phosphate,

7. A method according to claim 5, wherein said mixture of water including the salts ammonium sulpha, disodium hydrogen phosphate constitutes a fluid composition.