EP3414301A1

EP3414301A1 - Fire protection gel

Info

Publication number: EP3414301A1
Application number: EP17705010.1A
Authority: EP
Inventors: Robert SCHERF; Meinhard Langenbahn; Horst Eckard
Original assignee: Raschig GmbH
Current assignee: Raschig GmbH
Priority date: 2016-02-08
Filing date: 2017-01-30
Publication date: 2018-12-19
Also published as: WO2017137148A1

Abstract

The invention relates to fire protection gels containing a polymer produced from one or more sulphonated derivatives of unsaturated aliphatic carboxylic acids as monomers and water. The invention also relates to a method for producing the fire protection gel, comprising the following steps: providing one or more sulphonated derivatives of unsaturated aliphatic carboxylic acids as monomers; mixing with water; and polymerising the monomer/s. The invention further relates to the use of the fire protection gels for producing fire protection glass, wherein the fire protection gel is produced by polymerising the monomers between two glass panes.

Description

firefighting gel

The present invention relates to a fire protection gel, its preparation and its use in fire-resistant glass.

It has been known for some time to produce fire-resistant glass by embedding hydrogel layers between glass panes. See, e.g. DE 27 13 849 A1 and DE 35 30 968 C2. These hydro- or fire protection gels contain polymers based on acrylic acid derivatives, usually acrylamide, and water. Most are also salts, especially chlorides, included. Thermal insulation is achieved in the event of fire by the embedded gel layers, firstly by evaporating the water contained in the gel and secondly by crusting from the polymer and the salts contained therein. There are already different ones

Proposals for improved gels based on acrylic acid derivatives, for example in DE 102 37 395 B4 and DE 10 2005 018 842 A1.

A disadvantage of the known acrylic acid derivative-based gels is the toxicity of the monomers which are classified as mutagenic, carcinogenic and / or reprotoxic. It was therefore the object to provide a fire protection gel which is just as effective but less toxic.

Alternatives to the acrylate-based gels have already been described, for example dialdehyde-crosslinked polyvinyl alcohols in DE 38 38 806 C2 and organically modified alkali water glass DE 10 2006 035 262 A1. However, dialdehydes are also toxicologically problematic and organically modified

Alkali water glass requires special UV protection.

Furthermore, for example WO 00/65143 A1 and WO 2007/007115 A2 disclose hydrogels for medical applications which describe sulfonated carboxylic acid derivatives as monomers of hydrogels. Surprisingly, it has now been found that a fire protection gel based on a polymer containing sulfonated derivatives of unsaturated aliphatic

Carboxylic acids as monomers solves the task. These monomers and the polymers thereof are readily water soluble and the monomers become

predominantly classified neither as mutagen, nor as carcinogenic or reprotoxic. The gels work just as well as the known gels. Because the

Sulfonic acid groups not as acid but e.g. are present as salt or ester, the gels are not corrosive and corrosion inhibitors can and will preferably be omitted.

The invention therefore relates to fire protection gels comprising a polymer of one or more sulfonated derivatives of unsaturated aliphatic

Carboxylic acids as monomers and water. The invention further relates to a method for producing a fire protection gel, comprising the steps

Providing one or more sulfonated derivatives of unsaturated aliphatic carboxylic acids as monomers, mixing with water and

Polymerizing the monomer (s). Moreover, the invention relates to

Use of the fire protection gels for the production of fire protection glass, wherein the fire protection gel is obtained by polymerization between two glass panes. According to the invention only sulfonated derivatives of

unsaturated aliphatic carboxylic acids used as monomers.

Preferably, the monomers are esters or amides of aliphatic, unsaturated carboxylic acids substituted with an alkylsulfonic acid group. The carboxylic acid is in particular acrylic acid, methacrylic acid or itaconic acid. The monomers therefore preferably correspond to the formula 1 R ¹ -C (= QC (= O ⁾ -O-R ² -SO ₃ ^" or the formula 2 R ¹ -C (= C) -C (= O) -NH-R ² -S0 ₃ ^" in which R is H, a possibly branched and / or substituted Ci to C ₅ alkyl group or -CH ₂ -C (= 0) -O-R ² -S0 ₃ ^" and R ^{2 is} an optionally. is branched and / or substituted d to C ₅ alkylene group or -CH ₂ -CH 2 -N (CH 3) ₂ ⁺ -CH 2 CH ₂ -CH _second More preferably R ^{1 is} H, methyl, ethyl, iso-propyl, n-propyl or 2-hydroxy-propyl, most preferably H and methyl. The preferred radicals R ² are methylene, ethylene or -CH ₂ -CH ₂ -CH ₂ -, -CH (CH ₃ ) -CH ₂ -,

-CH ₂ -CH (OH) -CH ₂ - and -C (CH ₃ ) ₂ -CH ₂ -, most preferred

-CH ₂ -CH ₂ -CH ₂ - and -C (CH ₃ ) ₂ -CH ₂ -.

The sulphonic acid group is present, except for betaines, as salt or ester, preferably as salt. Preferred salts are the alkali metal salts, especially the sodium salts and the potassium salts. The esters are short chain esters, i. Methyl, ethyl, propyl or butyl ester, preferably methyl or ethyl ester, to ensure the water solubility of the polymers. In principle, longer-chain esters would also be useful if the polymers are water-soluble.

Particularly preferred monomers are acrylic acid (3-sulfopropyl) esters,

Potassium salt (available under the name Ralumer SPA from Raschig GmbH, DE) and 2-acrylamido-2-methylpropanesulfonic acid, sodium salt. In addition, the sulfonated methacrylic acid derivatives are methacrylic acid (3-sulfopropyl) ester, potassium salt (available under the name Ralumer SPM from Raschig GmbH, DE) and N, N-dimethyl-N- (2-methacryloxyethyl) -N- (3-sulfopropyl ) ammonium betaine (available under the name Ralumer SPE from Raschig GmbH, DE) advantageous. In addition, the use of itaconic acid bis (3-sulfopropyl) ester, dipotassium salt (available under the name Ralumer SPI from Raschig GmbH, DE) is possible. The monomers mentioned, insofar as they are not betaine, can each be in the form of sodium or potassium salt.

Another group of monomers whose use as monomers or preferably as comonomers is possible are sulfonated ethers or polyethers based on allyl alcohol, for example sodium 3- (allyloxy) -2-hydroxypropanesulfonate (available under the name Ralumer SPAE from Raschig GmbH, DE) and Polyethylene glycol allyl (3-sulfopropyl) diether, potassium salt (available under the name Ralumer SPPE from Raschig GmbH, DE).

As a rule, various of the listed compounds can and will be used together as comonomers. Useful gels contain from 5 to 30% by weight, preferably from 7.5 to 20% by weight and in particular from 10 to 15% by weight of polymerized monomers, based on the total weight of the fire protection gel.

In order to obtain non-flowable products despite low monomer concentrations, it is preferable to additionally add crosslinking agents, for example poly (ethylene glycol) diacrylate (PEGDA), to the reaction solution. Preference is given to using a poly (ethylene glycol) diacrylate having about 3 to 15 ethylene oxide units on average, in particular having about 10 ethylene oxide units in the middle. The amount of crosslinker is preferably in the range of 0.1 to 1 wt .-%.

The fire protection gels according to the invention preferably contain, like the known fire protection gels, one or more salts. These are usually chlorides, especially sodium chloride and magnesium chloride. These can be introduced according to the invention up to a total salt concentration of about 20% by weight, calculated as anhydrous salts. The optimal concentration depends on the ratio of the amounts of salt to each other. Other chlorides such as potassium chloride, calcium chloride or zinc chloride can also be used.

Furthermore, the fire protection gel can also contain water-miscible alcohols, for example ethylene glycol, glycerol and / or isopropyl alcohol, which are known as typical antifreeze additives. A concentration of at most 10% by weight of alcohol is expedient. It is also the use of optical brighteners, UV protectants and / or dyes conceivable. As an optical brightener is about Tinopal CBS-X (BASF SE, DE) in question. UV protectants can be selected from known groups such as, for example, the salicylates, the hydroxybenzophenones, the

Hydroxyphenylbenzotriazolen or hydroxyphenyltriazines are selected, provided that sufficient water solubility and no staining or turbidity of the gel occurs. The use of multiple UV protection agents is conceivable.

Furthermore, the fire-retardant gel may have adhesion promoter, e.g. Silane coupling agent, contained in the usual amounts.

A preferred fire protection gel contains:

10-15% by weight of polymerized sulfonated derivatives of unsaturated

carboxylic acids

0.2 to 0, 6 wt .-% of copolymerized crosslinker

10 to 20% by weight of salts (anhydrous)

The remainder of water and, if necessary, water-soluble alcohol (s) and the low required

Amounts of free radical generator and, if necessary, polymerization accelerator or their

Reaction products. A particularly preferred fire protection gel contains:

From 2 to 5% by weight of acrylic acid (3-sulfopropyl) ester and

7 to 12% by weight of 2-acrylamido-2-methylpropanesulfonic acid,

both as sodium or potassium salt and in polymerized form with

0.3 to 0.5 wt .-% crosslinked polymerized poly (ethylene glycol) diacrylate with about 10 ethylene oxide units

2 to 3 wt .-% NaCl

12 to 16 wt .-% MgCl ₂

Balance water and the reaction products or radicals of radical generator and polymerization accelerator. It is also the use of optical brighteners, UV protectants and / or dyes conceivable. The preparation according to the invention typically comprises, as a first step, the admixture of an aqueous solution containing from 20 to 60% by weight, preferably from 30 to 55% by weight and in particular about 50% by weight, of sulphonated derivatives of unsaturated carboxylic acids. If desired, the further components crosslinker and / or salt (s) are then added to the solution.

Thereafter, the dilution with water and / or alcohol and then the addition of the radical generator, so that the proportion of monomers from 5 to 30 wt .-%, preferably from 7.5 to 20 wt .-% and in particular from 10 to 15 wt .-% is.

The initiation of the polymerization is possible by typical free-radical initiators such as sodium persulfate. The amount of radical generator is e.g. in case of

Sodium persulfate 0.005 to 0.1% by weight, preferably 0.02 to 0.06 wt .-%.

In addition, a polymerization accelerator such as triethanolamine (TEA) can be used. Amounts of 0.01 to 0.5% by weight, especially 0.02 to 0.2% by weight, are useful. If no polymerization accelerator is used, temperatures of 50-70 ° C., preferably 55-65 ° C., are required. In the presence of a polymerization accelerator, the reaction can also be carried out at room temperature.

It is preferable to degas the solution before adding the radical generator. This can e.g. by applying a negative pressure. At temperatures of 10 to 35 ° C, a reduction of the pressure to 20 to 100 mbar for 0.5 to 2 hours is sufficient.

The polymerization is started by addition of the radical generator, if appropriate in admixture with the polymerization accelerator or after its addition, wherein the required temperature is to be observed. The polymerization usually takes a few minutes to a few hours, often from 15 to 60 minutes. To prevent premature polymerization during the preparation, transport or storage of the still containing no initiator

Monomer solution is preferably added an inhibitor. A particularly preferred inhibitor is 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, but also some aromatic compounds such as derivatives of phenol or hydroquinone have a stabilizing effect. In addition, several inhibitors can be used. The amounts are usually from 1 to 100 ppm, preferably 10 to 30 ppm per inhibitor. It should be noted that the

Transparency of the gels must be ensured, as well as no coloration may result. Addition of an inhibitor slows down the polymerization, i. the time to loss of fluidity, from the addition of the initiator depending on the selected inhibitor.

The fire protection gel according to the invention comes as the known

Fire protection gels usually as a filling between at least two

Glass panes used. For this purpose, the solution containing all components is introduced into a space between glass panes. Only there is the polymerization, the speed of which must be adjusted accordingly.

In addition to the simplest structure with two slices and a gel layer, structures with three, four or even more slices and accordingly two, three or even more gel layers are possible. The glass sheets may also be known per se, special, high-temperature resistant discs. The thickness of the panes and the fire protection gel layer corresponds to the usual dimensions of the respective fire resistance class. In case of fire, the gel cools the side of the pane facing away from the fire by evaporating water and also forms an insulating crust, at the latest when the pane facing the fire is no longer intact.

When using a crosslinker, which is usually the case, that is

Brandschutzgel a covalent network and no longer flows when it once formed. Therefore, the solution must be placed between the discs prior to gelling. The time until the insertion of the

Gelation must be sufficient here and can be adjusted by varying the amount of initiator and accelerator if necessary, taking into account the inhibitor used.

The invention will be explained with reference to the following examples, but without being limited to the specifically described embodiments. Unless otherwise stated or necessarily different from the context, percentages are based on weight, in case of doubt on the total weight of the mixture.

The invention also relates to all combinations of preferred embodiments, as far as these are not mutually exclusive. The information "about" or "approx." in conjunction with a numerical indication, means that at least 10% higher or lower values or 5% higher or lower values and in any case 1% higher or lower values are included.

example 1

In a 400 ml beaker, 66.54 g of 2-acrylamido-2-methylpropanesulphonic acid (AMPS) were dissolved in 94.27 g of demineralized water (demineralized water). With stirring, cooling in the ice-water bath to 0 ° C and introduction of compressed air then 12.84 g of sodium hydroxide were added gradually and the pH was adjusted to 9.7 with another 2.41 g of 1 M sodium hydroxide solution. The yellowish-colored solution was then decolorized with 1.75 g of activated carbon ("1 wt .-% based on the solution) and stirred vigorously for one hour. The subsequent filtration caused a mass loss of 8.63 g, but the solution had only a slight yellowish hue. The pH was now 4.0, so again 0.98 g of 1 M sodium hydroxide solution were added until a pH of 9.6. The total mass of the solution was 168.63 g. Finally, 22.54 g of acrylic acid (3-sulfopropyl) ester, potassium salt (SPA) and 3.03 g of polyethylene were added. glycol) diacrylate (PEGDA) with vigorous stirring and the pH adjusted to 9.5 with 8 drops of 1 M sodium hydroxide again.

The composition of the solution according to the weighings and taking into account the filtration loss was: 11, 6 wt .-% SPA, 1, 56 wt .-% PEGDA and 36.1 wt .-% Na-AMPS. As a result of the used

In addition, raw materials usually result in a content of the inhibitor

Hydroquinone monomethyl ether in the range of 10 to 15 ppm.

In 25.84 g of this solution were dissolved 30.01 g of magnesium chloride hexahydrate (MgC-b × 6H ₂ O) and 2.49 g of sodium chloride (NaCl), and the solution was diluted with 34.99 g of deionized water. After subsequent filtering, with a loss of 2.73%, the solution was degassed for about one hour in a vacuum oven at room temperature and a pressure of about 50 mbar. Thereafter, an initiator solution of 0.104 g of triethanolamine (TEA) and 0.0345 g of sodium persulfate in 6.33 g of demineralized water was added and stirred briefly. Between 17 and 20 minutes after the addition of the initiator solution, the appearance of a gel phase could be observed.

The solution contained, according to the initial weight taking into account the filter loss: 3.0% by weight SPA, 0.4% by weight PEGDA, 9.3% by weight Na-AMPS, 2.5% by weight NaCl and 14 , 1 wt .-% MgCl ₂ (anhydrous).

Example 2

In a 10 L flat-bottomed flask, 3992.4 g AMPS were dissolved in 4878 g demineralized water with stirring and introduction of compressed air. Subsequently, the

Neutralization with 1545.6 g of a 49.8% sodium hydroxide solution, wherein a temperature of 30 ° C in the solution was not exceeded. With a further 28.6 g of a 25% sodium hydroxide solution, the pH was adjusted to 9.2. This was followed by the addition of 1395.6 g SPA. The associated renewed reduction of the pH was compensated with 5.9 g of 25% sodium hydroxide solution, so that a slightly alkaline solution. From this, 521.7 g were sampled. The remaining solution was mixed with 58 g of activated carbon, stirred at a temperature of about 30 ° C for about 3 hours and then filtered. There were 11275 g of solution obtained from the further 500 g were sampled. 169.2 g of PEGDA were added to the remaining 10775 g and the now slightly acidic solution was brought to a pH of 7.6 with 8.6 g of the 25% sodium hydroxide solution.

The composition of the solution according to the weights and taking into account the filtration loss and the samples taken were: 11, 6 wt .-% SPA, 1, 55 wt .-% PEGDA, 36.7 wt .-% Na-AMPS. As a result of the raw materials used, there was also a content of 13 ppm of the inhibitor hydroquinone monomethyl ether.

In 25.84 g of this solution 29.97 g of MgCl ₂ -6 ₂ 0 and 2.53 g NaCl dissolved H and the solution is diluted with 34.99 g of deionized water. After subsequent filtering to give a loss of 2.89%, the solution was degassed for about one hour in a vacuum oven at room temperature and a pressure of about 50 mbar. Thereafter, an initiator solution of 0.097 g TEA, 0.0345 g sodium persulfate and 6.34 g DI water was added and stirred briefly. About 18 minutes after the addition of the initiator solution, the appearance of a gel phase could then be observed.

The solution contained, according to the initial weight taking into account the filter loss: 3.0% by weight SPA, 0.4% by weight PEGDA, 9.5% by weight Na-AMPS, 2.5% by weight NaCl and 14 , 0 wt .-% MgCl ₂ (anhydrous).

Example 3

In fire tests, hydrogels prepared from the monomer solution of

Example 2 containing 11, 6 wt .-% SPA, 1, 55 wt .-% PEGDA, 36.7 wt .-% Na AMPS, examined and confirmed the effectiveness. Example 4

8450 g of demineralised (DI) water were placed in a temperature-controlled 20 L jacketed flat bottom flask equipped with a reflux condenser, a 1 L dropping funnel, a Pt100 temperature sensor, a pH measuring chain and a glass tube for introducing air. Subsequently, with stirring and introduction of air at 20 ° C., 6990 g of AMPS were dissolved and 525 mg

4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl (4-hydroxy-TEMPO) as

Polymerization inhibitor added to the solution. To neutralize the AMPS, 2740 g of a 49.2% sodium hydroxide solution were metered in slowly via the dropping funnel, the temperature of the solution not exceeding 30 ° C. With 19.7 g of a 25% sodium hydroxide solution, a pH of 9.6 was set. Then, 2440 g of SPA were added with stirring. The solution thus obtained was stirred with 103 g of activated carbon for two hours at a temperature of 20 to 25 ° C. After subsequent filtration, 20420 g of the solution were present. This still 319.6 PEGDA were added and adjusted with 14.0 g of a 25% sodium hydroxide solution to a pH of 7.5.

The composition of the solution according to the HPLC analysis was 37.8% Na-AMPS, 12.1% SPA and 1.42% PEGDA. The content of 4-hydroxy TEMPO corresponding to the initial weight was 25 ppm. As a result of the raw materials used, there was also a content of 15 ppm

Hydroquinone monomethyl ether.

Example 5:

As a test procedure, hydrogels were prepared from a monomer solution prepared only in 2 L scale according to Example 4. To this was dissolved in 25.84 g of this solution, 30.00 g of magnesium chloride hexahydrate and 2.50 g of sodium chloride and diluted with 35.00 g of water. The solution was then degassed for one hour at room temperature and a pressure of about 50 mbar in a vacuum oven. The resulting loss of water of 380 mg was compensated by adding new demineralised water. The solution was then overlaid with argon and then the initiator solution of 0.035 g of sodium persulfate, 0.1 g of triethanolamine and 6.53 g of water was added. After brief stirring, a portion of the solution was transferred to a rolled edge glass with argon overlaid and sealed with a crimp cap. The gelling time from the addition of the initiator solution to the time when the fluidity of the material is no longer observed was determined. It was 90 minutes.

Claims

claims

1. fire protection gel containing a polymer of one or more

sulfonated derivatives of unsaturated carboxylic acids and water, wherein the sulfonic acid group is present as a salt, as an ester or as part of a betaine.

2. Fire protection gel according to claim 1, characterized in that the one or more sulfonated derivatives of unsaturated carboxylic acids are sulfonated esters or amides of aliphatic, unsaturated carboxylic acids.

3. fire protection gel according to claim 2, characterized in that the

aliphatic, unsaturated carboxylic acid is acrylic acid, methacrylic acid or itaconic acid.

4. fire protection gel according to claim 2 or 3, characterized in that the sulfonic acid group is present as a salt, preferably as alkali metal salt,

especially as the sodium salt or potassium salt.

5. fire protection gel according to one of claims 1 to 4, characterized

in that the one or more sulfonated derivatives of unsaturated carboxylic acids are selected from acrylic acid (3-sulfopropyl) ester, 2-acrylamido-2-methylpropanesulfonic acid, methacrylic acid (3-sulfopropyl) -ester, N, N-dimethyl-N- (2-methacryloxyethyl) -N- (3-sulfopropyl) ammonium betaine, itaconic acid bis (3-sulfopropyl) ester and mixtures thereof, preferably as sodium or potassium salt.

6. fire protection gel according to one of claims 1 to 5, characterized

characterized in that sulfonated ethers or sulfonated polyethers based on allyl alcohol are copolymerized as additional monomers in the polymer.

7. fire protection gel according to claim 6, characterized in that sodium 3- (allyloxy) -2-hydroxypropanesulfonate and / or polyethylene glycol allyl (3-sulfopropyl) ether potassium salt are copolymerized as additional monomers.

8. fire protection gel according to one of claims 1 to 7, characterized

in that one or more crosslinkers, for example poly (ethylene glycol) diacrylate, are copolymerized in the polymer.

9. fire protection gel according to one of claims 1 to 8, characterized

characterized in that it contains salts selected from sodium chloride,

Potassium chloride, calcium chloride, magnesium chloride, zinc chloride and

Mixtures thereof, in particular sodium chloride and / or

Magnesium chloride, wherein preferably from 1 to 20 wt .-% salts are included.

10. fire protection gel according to one of claims 1 to 9, characterized

in that one or more UV protection agents and / or

Adhesion promoters and / or optical brighteners are included.

11. fire protection gel according to one of claims 1 to 10, characterized

in that it contains water-miscible alcohols, for example ethylene glycol, glycerol or isopropanol, preferably in an amount of 10% by weight or less.

12. A process for producing a fire protection gel, comprising the steps of providing one or more sulfonated derivatives of

unsaturated carboxylic acids, mixing with water and polymerizing the sulfonated derivatives of unsaturated carboxylic acids.

13. The method according to claim 12, characterized in that an aqueous solution containing from 5 to 30 wt .-%, preferably from 7.5 to

20 wt .-% and in particular from 10 to 15 wt .-% of / the sulfonated derivatives of unsaturated carboxylic acids is used.

14. The method according to claim 12 or 13, characterized in that

Crosslinking agent and / or salt (s) and / or water-miscible (miscible) alcohol (s) are added.

15. The method according to any one of claims 12 to 14, characterized in that the polymerization is initiated with a free radical generator such as sodium persulfate.

16. The method according to any one of claims 12 to 15, characterized in that a polymerization accelerator such as triethanolamine (TEA) is used.

17. The method according to any one of claims 12 to 16, characterized in that a polymerization inhibitor such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl is used.

18. The method according to any one of claims 12 to 17, characterized in that one or more UV-protecting agents and / or adhesion promoters and / or optical brightener are added.

19. Use of a fire protection gel according to one of claims 1 to 11 for the production of fire protection glass, wherein the fire protection gel is prepared by polymerization of the monomers between at least two glass sheets.