Intumescent epoxy-based composition having improved fireproofing properties, and use of same

Abstract

The invention relates to an intumescent composition containing: (a) at least one compound having at least two epoxy groups; (b) at least one compound having at least two amino groups which can react with the epoxy groups; (c-1) intumescence additives selected from the group consisting of a blowing agent and a dehydrogenation catalyst and combinations thereof; and / or (c-2) a thermally expandable compound; and (d) at least one plasticiser; wherein the cured composition forms an insulating layer in the event of fire.

Description

[0001] Epoxy-based intumescent composition with improved fire protection properties and its use

[0002] DESCRIPTION

[0003] The present invention relates to an intumescent composition, in particular a fire protection composition with intumescent properties, which contains a binder based on epoxy resin compound, and to its use for fire protection, in particular for coatings of components, such as columns, beams, or truss rods, to increase the fire resistance duration.

[0004] Intumescent fire protection compounds, also known as intumescent fire protection compounds, are typically applied to the surface of building components to form coatings to protect them from fire or the effects of high temperatures, such as those resulting from a fire. This is achieved by the coating expanding upon exposure to high temperatures, such as those resulting from a fire, and forming an ash layer that acts as an insulator and prevents the heat from being drawn away from the building component for a certain period of time.

[0005] Steel structures have become an integral part of modern architecture, although they have one significant disadvantage compared to reinforced concrete construction. Above approximately 500°C, the load-bearing capacity of steel drops by 50%, meaning the steel loses its stability and load-bearing capacity. Depending on the fire load, for example, in the case of direct fire exposure (approximately 1000°C), this temperature can be reached after just 5-10 minutes, which often leads to a loss of load-bearing capacity of the structure. The objective of fire protection, particularly steel fire protection, is to delay the time until a steel structure loses its load-bearing capacity in the event of a fire for as long as possible, thus saving human lives and valuable property.

[0006] The building codes of many countries require corresponding fire resistance periods for certain steel structures. These are defined by so-called F classes such as F 30, F 60, F 90 (fire resistance classes according to DIN 4102-2) or American classes according to ASTM, etc. According to DIN 4102-2, for example, F 30 means that a load-bearing steel structure must withstand fire for at least 30 minutes in the event of a fire under standard conditions. This is usually achieved by slowing the heating rate of the steel, e.g., by coating the steel structure with intumescent coatings. These coatings are coatings whose components expand in the event of a fire, forming a solid, microporous carbon foam.This creates a thick, fine-pored foam layer, the so-called ash crust, which, depending on its composition, has strong thermal insulation properties and thus delays the heating of the component, so that the critical temperature of approximately 500°C is reached after 30, 60, 90, 120 minutes, or up to 240 minutes at the earliest. The achievable fire resistance always depends on the applied layer thickness of the coating, or rather the thickness of the resulting ash crust. Closed profiles, such as pipes, require approximately twice the amount of foam compared to open profiles, such as beams with a double-T profile, for comparable solidity. To ensure compliance with the required fire resistance times, the coatings must have a certain thickness and be able to form the most voluminous and thus well-insulating ash crust possible when exposed to heat, which remains mechanically stable throughout the fire exposure period.

[0007] There are various systems for this purpose, with a large proportion of the products available on the market being based on water-based dispersions.

[0008] Intumescent coatings can also be epoxy resin-based. This type of coating always requires a component added to the system as a hardener to ensure the coating cures. For this reason, these coatings are two-component products. Such coatings are known, for example, from GB 1575708 A1, GB 2121056 A1, DE 102006056403 A1, EP 3085744 A1, and EP 0295496 A2.

[0009] WO 20 / 253732 A1 describes an insulating coating composition comprising a chemically modified epoxy resin component, a curing agent, reinforcing fibers and low-density fillers for protecting steel components from excessively rapid temperature drops.

[0010] Epoxy resin coatings used for intumescent applications are often characterized by good adhesion to substrates such as components, high hardness, and resistance to thermal degradation and attack by corrosive chemicals. However, epoxy resin coatings also have disadvantages in construction applications that limit their use, particularly for fire protection. In the event of a fire, an extremely compact and hard ash develops, which has only insufficient insulating effect and is easily removed. Therefore, the fire protection properties of these coatings are often insufficient to meet the requirements mentioned above.

[0011] There is therefore a need for epoxy resin coatings that do not have the disadvantages mentioned, and in particular, that form a better insulating ash and thus meet the requirements of the regulatory provisions.

[0012] The present invention is based on the object of improving the fire protection properties of intumescent epoxy resin coatings. In particular, the object is to reduce the hardness of the ash crust formed in the event of a fire and thus increase the insulating effect of the ash crust, compared to the known and commercially available epoxy resin coatings.

[0013] This object is achieved by a composition according to claim 1. Preferred embodiments can be found in the dependent claims. The advantages achieved are, in particular, that the addition of a plasticizer to an epoxy-amine-based composition can significantly improve the ash structure and thus also improve fire performance in the event of a fire.

[0014] A first subject of the invention is therefore an intumescent composition comprising (a) at least one compound having at least two epoxy groups, (b) at least one compound having at least two amino groups, (c-1) intumescent additives selected from the group consisting of blowing agent, and dehydrogenation catalyst and combinations thereof and / or (c-2) a thermally expandable compound and (d) at least one plasticizer, wherein the cured composition forms an insulating layer in the event of fire.

[0015] Another object of the invention is the use of the composition as a fire protection coating composition.

[0016] A still further object of the invention is the use of a plasticizer in an epoxy-amine-based fire protection composition to improve the stability and structure and thus the resistance of the ash crust formed in the event of fire.

[0017] For a better understanding of the invention, the following explanations of the terminology used herein are considered useful. Within the meaning of the invention:

[0018] - “intumescent composition” means a curable mixture containing an intumescent coating material orProvides a coating, in particular a mixture with a binder of mutually reacting components, such as an epoxy resin and a curing agent, for example an amino compound, and further components, such as additives and fillers; “fire protection coating” means a coating for the purpose of fire protection, where the fire protection consists in protecting a substrate coated therewith from the effects of heat; - “multifunctional” means that the corresponding compound has more than one functional group per molecule; accordingly, multifunctional in the context of epoxy compounds means that these have more than one epoxy group per molecule, and in relation to thiol-functionalized compounds means that these have at least two thiol groups per molecule; the total number of the respective functional groups is the functionality of the corresponding compound;.

[0019] - ‘chemical intumescence’ means the formation of a voluminous, insulating ash layer by means of matched compounds that react with each other when exposed to heat;

[0020] - ‘physical intumescence’ means the formation of a voluminous insulating layer by the expansion of a compound which, without any chemical reaction having taken place between two compounds, releases gases when heated, causing the volume of the compound to increase several times its original volume;

[0021] - “insulating layer forming” means that in the event of a fire a solid microporous carbon foam is formed, so that the fine-pored and thick foam layer formed, the so-called ash crust, insulates a substrate against heat, depending on its composition;

[0022] - a "carbon supplier" is an organic compound which leaves behind a carbon framework through incomplete combustion and does not burn completely to carbon dioxide and water (carbonification); these compounds are also referred to as "carbon framework formers"; an "acid former" is a compound which, when exposed to heat, i.e. above approximately 150°C, for example through decomposition, forms a non-volatile acid and thereby acts as a catalyst for carbonification; it can also contribute to reducing the viscosity of the melt of the binder; the term "dehydrogenation catalyst" is used synonymously here;

[0023] - a "blowing agent" is a compound which decomposes at elevated temperature with the development of inert, i.e. non-combustible gases and which expands the carbon framework formed by carbonification and, where appropriate, the softened binder into a foam (intumescence); this term is used synonymously with "gas-forming agent";

[0024] - an "ash crust stabilizer" is a so-called framework-forming compound that stabilizes the carbon framework (ash crust) formed from the interaction of carbon formation from the carbon source and the gas from the propellant, or from physical intumescence. The basic mechanism of action is that the inherently very soft carbon layers are mechanically strengthened by inorganic compounds. The addition of such an ash crust stabilizer contributes to a significant stabilization of the intumescent crust in the event of a fire, as these additives increase the mechanical strength of the intumescent layer and / or prevent it from dripping off, thereby maintaining or enhancing the insulating effect of the foam.

[0025] - An "oligometry" is a molecule with 2 to 5 repeating units, and a "polymer" is a molecule with 6 or more repeating units. They can have structures that are linear, branched, star-shaped, twisted, hyperbranched, or cross-linked. Polymers can have a single type of repeating unit ("homopolymers") or they can have more than one type of repeating unit ("copolymers"). As used herein, "resin" is a synonym for polymer.

[0026] - "Epoxy equivalent mass" means the amount of epoxy resin in [g] that has one equivalent [Val] of epoxy functions and is calculated from the molar mass M in [g / mol] divided by the functionality f in [Val / mol]; (EEW ​​[g / Val]). Plasticizer (d)

[0027] According to the invention, the intumescent composition contains a plasticizer.

[0028] Surprisingly, it has been shown that a plasticizer in an epoxy-amine-based intumescent composition brings several advantages.

[0029] The inventors discovered that the plasticizer offers several advantages. Not only does it soften the cured coating, but it also significantly alters the ash structure in the event of a fire. Without the plasticizer, the ash structure is very laminar and platelet-like, and it quickly disintegrates or evaporates, thus no longer providing adequate protection for the substrate. Furthermore, a hard or brittle ash crust tends to crack, further reducing the insulating effect.

[0030] In the event of a fire, the fire-protection coating with plasticizers forms a sponge-like cell structure of the resulting ash. This makes the ash layer significantly more stable, while also increasing the insulating effect due to the cells formed. Furthermore, the resulting ash is significantly softer and more flexible than the ash layers of coatings without plasticizers. This reduces the tendency for cracking in the ash layer and thus maintains the insulating effect for longer. This leads to an improvement in fire protection properties, which is reflected in an extension of the time to failure (TTF) of up to 7.5%.

[0031] Another advantage of adding the plasticizer is that the viscosity of the composition is reduced, so that solvents that are volatile (VOCs) and have a negative impact on the environment and the user no longer need to be used to adjust the viscosity of the composition to a suitable value.

[0032] Suitable plasticizers are derivatives of benzoic acid, phthalic acid, e.g. phthalates such as dibutyl, dioctyl, dicyclohexyl, diisooctyl, diisodecyl, dibenzyl or butylbenzyl phthalate, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, phosphoric acid and citric acid, alkyl phosphate esters and derivatives of polyesters, polyethers and epoxides and the like, C10-C2i-alkylsulfonic acid esters of phenol, polyesters obtainable from linear or branched, saturated or unsaturated C6-C2i-monocarboxylic acids and multifunctional alcohols or their ethoxylated derivatives, and alicyclic carboxylic acid esters.

[0033] In a preferred embodiment, the plasticizer is selected from the group consisting of carboxylic acid esters, such as phthalates, in particular diisononyl phthalate (DINP), diisodecyl phthalate (DIDP) or di(2-propylheptyl)phthalate (DPHP), hydrogenated phthalates, in particular hydrogenated diisononyl phthalate (DINCH), terephthalates, in particular dioctyl terephthalate, trimellitates, adipates, in particular dioctyl adipate, azelates, sebacates, polyols, in particular polyoxyalkylene polyol or polyester polyols, benzoates, glycol ethers, glycol esters, organic phosphates, phosphonates or sulfonates, polybutene, polyisobutylene or plasticizers derived from natural fats or oils, in particular from epoxidized soybean oil or linseed oil.

[0034] Particularly preferred are phosphoric acid esters, citrate esters and phthalates, in particular diisononyl phthalate (DINP), diisodecyl phthalate (DIDP) or di(2-propylheptyl) phthalate (DPHP), hydrogenated phthalates, in particular hydrogenated diisononyl phthalate (DINCH), with hydrogenated diisononyl phthalate (DINCH) being very particularly preferred.

[0035] With regard to improving the ash structure, the plasticizer may be present in a concentration of up to 10% by weight based on the total weight of the intumescent composition.

[0036] To improve fire performance, the plasticizer is preferably present in an amount of 2 wt.% to 10 wt.%, preferably 2 wt.% to 7.5 wt.%, based in each case on the total weight of the intumescent composition. Epoxy resin (a)

[0037] Suitable compounds (a) having at least two epoxy groups (also referred to herein as epoxy resin) include epoxy resins customary in epoxy chemistry. These are obtained in a known manner, for example, from the oxidation of the corresponding olefins or from the reaction of epichlorohydrin with the corresponding polyols, polyphenols, or amines. Examples of suitable epoxy resins include: reaction products of polyhydroxy compounds, in particular polyhydric phenols or phenol-aldehyde condensates, with epihalohydrins or their precursors, in particular: a) reaction products of epichlorohydrin with bisphenol A; b) reaction products of epichlorohydrin with bisphenol S; c) phenol- or cresol-based epoxy novolaks; d) aromatic glycidylamine resins; e) epoxy resins without aromatic structural units; and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

[0038] Particularly suitable as epoxy resins are so-called liquid polyepoxide resins, hereinafter referred to as "liquid resins." These have a glass transition temperature typically below 25°C, in contrast to so-called solid resins, which have a glass transition temperature above 25°C and can be ground into pourable powders at 25°C. Suitable compounds are the products of the glycidylation of:

[0039] Dihydroxybenzene derivatives such as resorcinol, hydroquinone and pyrocatechol;

[0040] - other bisphenols or polyphenols, such as bis-(4-hydroxy-3-methylphenyl)-methane, 2,2-bis-(4-hydroxy-3-methylphenyl)-propane (bisphenol C), bis-(3,5-dimethyl-4-hydroxyphenyl)-methane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane, 2,2-bis-(4-hydroxy-3- tert.-butylphenyl)-propan, 2,2-Bis-(4-hydroxyphenyl)-butan (Bisphenol-B), 3,3- Bis-(4-hydroxyphenyl)-pentan, 3,4-Bis-(4-hydroxyphenyl)-hexan, 4,4-Bis-(4- hydroxyphenyl)-heptan, 2,4-Bis-(4-hydroxyphenyl)-2-methylbutan, 2,4-Bis-(3,5- dimethyl-4-hydroxyphenyl)-2-methylbutan, 1 , 1 -Bis-(4-hydroxyphenyl)- cyclohexan (Bisphenol-Z), 1 ,1-Bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexan (Bisphenol-TMC), 1 ,1-Bis-(4-hydroxyphenyl)-1-phenyl-ethan, 1 ,4-Bis[2-(4- hydroxyphenyl)-2-propyl]-benzol) (Bisphenol-P), 1 ,3-Bis-[2-(4-hydroxyphenyl)-2- propyl]-benzol) (Bisphenol-M), 4,4'-Dihydroxydiphenyl (DOD), 4,4'- Dihydroxybenzophenon, Bis-(2-hydroxynaphth-1-yl)-methan, Bis-(4- hydroxynaphth-1-yl)-methan 1 ,5-Dihydroxy-naphthalin, Tris-(4-hydroxyphenyl)- methan, 1 , 1 ,2,2-T etrakis-(4-hydroxyphenyl)-ethan Bis-(4-hydroxyphenyl)-ether, Bis-(4-hydroxyphenyl)sulfon;.

[0041] Condensation products of phenols with formaldehyde obtained under acidic conditions, such as phenol novolaks or cresol novolaks, also called bisphenol F novolaks; aromatic amines, such as aniline, toluidine, 4-aminophenol, 4,4'-methylenediphenyldiamine (MDA), 4,4'-methylenediphenyldi-(N-methyl)-amine, 4,4'-[1,4-phenylene-bis-(1-methyl-ethylidene)]-bisaniline (bisaniline-P), 4,4'-[1,3-phenylene-bis-(1-methyl-ethylidene)]-bisaniline (bisaniline-M); and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

[0042] Further preferred within the meaning of the invention are reaction products of epichlorohydrin with bisphenol A having an epoxide equivalent mass (EEW) < 550 g / eq; reaction products of epichlorohydrin with bisphenol F, the simplest representative of the novolaks, having an EEW < 500 gA / eq; any mixtures of these two reaction products, reaction products of any mixture of bisphenol A and bisphenol F with epichlorohydrin, epoxy resins such as hydantoin-based epoxy resins or diglycidyl ethers of hydrogenated bisphenol A or bisphenol F; and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

[0043] Particularly preferred are reaction products of epichlorohydrin with bisphenol A with an EEW < 330 gA / al; reaction products of epichlorohydrin with bisphenol F, the simplest representative of the novolaks, with an EEW < 300 g / val, any mixtures of these two reaction products, reaction products of any mixture of bisphenol A and bisphenol F with epichlorohydrin with an EEW < 330 g / val, 5,5-dimethyl-1,3-bis(2,3-epoxypropyl)-2,4-imidazolidinedione; 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane; and mixtures of two or more such epoxy resins in any ratio and in any degree of purity.

[0044] Very particular preference is given to reaction products of epichlorohydrin with bisphenol A having an EEW < 200 gA / al, such as, for example, Epilox® A 17-01, Epilox® A 18-00, Epilox® A 19-00, Epilox® A 19-02, Epilox® A 19-03 or Epilox® A 19-04 from Leuna-Harze GmbH, represented by the following formula, wherein 0 < n < 0.2;

[0045] Reaction products of epichlorohydrin with bisphenol F, the simplest representative of the novolaks, with an EEW< 185 gA / al, such as Epilox® F 16-01 or Epilox® F 17-00 from Leuna-Harze GmbH, represented by the following formula, where 0 < n < 0.2; as well as mixtures of two or more such epoxy resins in any ratio and in any degree of purity, such as, for example, Epilox® AF 18-30, Epilox® 18-50 or Epilox® T 19-27 from Leuna-Harze GmbH, as well as reaction products of any mixture of bisphenol A and bisphenol F with epichlorohydrin with an EEW < 200 g / eq. An aliphatic or cycloaliphatic polyepoxide is also suitable as an epoxy resin, such as, for example: a glycidyl ether of a saturated or unsaturated, branched or unbranched, cyclic or open-chain C2 to C50 diol, such as, for example, ethylene glycol, propylene glycol, butylene glycol, hexanediol, octanediol, a polypropylene glycol, dimethylolcyclohexane, neopentyl glycol or dibromoneopentyl glycol;a glycidyl ether of a tri- or tetrafunctional, saturated or unsaturated, branched or unbranched, cyclic or open-chain polyol such as castor oil, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol or glycerin, as well as alkoxylated glycerin or alkoxylated trimethylolpropane; a hydrogenated bisphenol A, F or A / F liquid resin, or the glycidylation products of hydrogenated bisphenol A, F or A / F; an N-glycidyl derivative of amides or heterocyclic nitrogen bases, such as triglycidyl cyanurate and triglycidyl isocyanurate, as well as reaction products of epichlorohydrin and hydantoin.

[0046] Also possible as an epoxy resin are a bisphenol A, F or A / F solid resin, which has a similar structure to the liquid resins of the two formulas already mentioned, but instead of the index n has a value of 2 to 12, and has a glass transition temperature above 25°C.

[0047] Finally, epoxy resins from the oxidation of olefins, for example from the oxidation of vinylcyclohexene, dicyclopentadiene, cyclohexadiene, cyclododecadiene, cyclododecatriene, isoprene, 1,5-hexadiene, butadiene, polybutadiene or divinylbenzene, are also suitable as epoxy resins.

[0048] As compound (a), a single compound (a) or a mixture of two or more different compounds (a) can be used.

[0049] The compound (a) having at least two epoxy groups is preferably present in the intumescent composition in an amount of 9 to 20 wt.%, preferably 10 to 19 wt.% and more preferably 11 to 18 wt.%, based on the total weight of the composition.

[0050] Amino compounds (b)

[0051] The at least one compound (b) having at least two amino groups (herein also referred to as amino compound(s)) can in principle be selected from low-molecular-weight materials, oligomers, or polymeric materials. The amino compound can have primary and / or secondary amino groups, with the amino compound preferably having 2 to 10, more preferably 2 to 6 amino groups per molecule and 2 to 200 carbon atoms.

[0052] A suitable amino compound is a straight-chain or branched, optionally substituted aliphatic or alicyclic alkyl radical with at least one, but preferably two or more, primary and / or secondary amino groups. Amino compounds with two or more amino groups are also referred to herein as polyamines.

[0053] For the purposes of the invention, "aliphatic" means an acyclic or cyclic, saturated or unsaturated carbon compound, excluding aromatic compounds; "alicyclic" means a compound with a carbocyclic ring structure, excluding benzene derivatives or other aromatic systems; and "aromatic" means a compound that follows the Hückel (4n+2) rule; and "amines" means compounds derived from ammonia by replacing one, two or three hydrogen atoms with hydrocarbon groups and having the general structures RNH2 (primary amines), R2NH (secondary amines) and R3N (tertiary amines) (IIIPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by AD McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997)).

[0054] Suitable examples of polyamines having two amino groups include diamines such as ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine, 4,7-dioxadecane-1,10-diamine, dodecamethylenediamine, 4,9-dioxadodecane-1,12-diamine, 7-methyl-4,10-dioxatridecane-1,13-diamine, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,2-

[0055] Bis(aminomethyl)cyclohexane (1,2-BAC), hexamethylenediamine (HMD), 1,2- and 1,4- diaminocyclohexane (1,2-DACH and 1,4-DACH), isophoronediamine, bis(3-methyl-4-aminocyclohexyl)methane, urea, 2,2-bis(4-aminocyclohexyl)propane, 3-amino-1-(methylamino)propane, 3-amino-1-(cyclohexylamino)propane and N-(2-hydroxyethyl)ethylenediamine.

[0056] The amines can be used individually or in a mixture of two or more of the amines mentioned.

[0057] Suitable examples of polyamines having three amino groups per molecule include polyamines such as tris(2-aminoethyl)amine, bis(3-aminopropyl)methylamine, melamine, and polyetheramines such as JEFFAMINE® (registered trademark) ED and T series products, as represented by the following formula: where E is the residue of an aliphatic triol and x, y, and z are integers whose sum is from 5 to 85, whereby the sum need not be an integer if the product is a mixture of compounds with different x, y, and / or z. The JEFFAMINE® D series products with 2 amino groups are also suitable.

[0058] Other suitable polyamines with three to ten amino groups per molecule are polyalkylenepolyamines of the formula: wherein R' and R" may be the same or different and represent (cyclo)alkylene groups having 1 to 6, preferably 1 to 4, carbon atoms and n represents an integer between 1 and 8 and preferably between 1 and 4. Examples of such polyamines are: diethylenetriamine, dipropylenetriamine and dibutylenetriamine.

[0059] Other suitable polyamines that can be used include adducts of amino compounds with a polyfunctional epoxy, isocyanate, maleate, dimalate, or (meth)acryloyl compound, such that the resulting compound has two or more amino groups (primary or secondary) per molecule. Some examples of such polyamines are disclosed in US Patent 4,772,680.

[0060] It would also be possible to use polyhydrazides such as the dicarboxylic acid bishydrazides of the formula: where R represents a covalent bond or a polyalkylene, preferably polymethylene, or alicyclic group having 1 to 34 carbon atoms. Examples of suitable dihydrazides include: oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, cyclohexane dicarboxylic acid bishydrazide, azelaic acid bishydrazide, and sebacic acid dihydrazide.

[0061] The polyamine compound can in principle also be an organic polymer with an average of at least two amino groups per molecule, for example an olefinic polymer, a polyester polymer or a polyurethane polymer with pendant and / or terminal amino groups (usually at least lateral amino groups). Such a polymer is, in particular, an olefinic polymer which has at least lateral amino groups. An olefinic polymer which has the amino groups along the carbon chain is preferably a copolymer which is prepared by first reacting, using a radically initiated polymerization process, a precursor copolymer comprising polymerized units of at least one olefinically unsaturated monomer with an amine precursor group(s) (i.e. a group which can subsequently be reacted to provide a pendant amino group) and at least one other olefinically unsaturated monomer (e.g.a monomer that does not provide an amine precursor group), and then reacting at least a portion of the amine precursor groups to provide chain-dependent amino functional groups. For example, the precursor groups of the amino groups can be carboxyl groups, which are converted to provide amino groups by an imination reaction with an alkyleneimine, such as ethyleneimine or propyleneimine.

[0062] Alternatively or in addition to the amino compounds mentioned, amide-containing polyamines, so-called polyamidoamines, can also be used as curing agents or co-curing agents for the epoxy resin. These polyamines are obtainable from the reaction of dicarboxylic acids with excess polyamine. Starting materials for the production of polyamidoamides can be, in particular, fatty acids with 8 to 24 carbon atoms and one or more dicarboxylic acid groups. The polyamines are selected in particular from the group of aliphatic polyamines, such as ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. Suitable polyamidoamines are commercially available, for example under the brand names Versamid® (from Cognis), Aradur® (from Huntsman), Euretek® (from Huntsman), Beckopox® (from Cytec), and Hexamoll® (from BASF).

[0063] In a preferred embodiment of the invention, the compound having at least two amino groups is selected from the group consisting of ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine, 4,7-dioxadecane-1,10-diamine, dodecamethylenediamine, 4,9-dioxadodecane-1,12-diamine, 7-methyl-4,10-dioxatridecane-1,13-diamine, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,2-bis(aminomethyl)cyclohexane (1,2-BAC), hexamethylenediamine (HMD), 1,2- and 1 ,4-Diaminocyclohexane (1,2-DACH and 1,4-DACH), isophoronediamine, bis(3-methyl-4-aminocyclohexyl)methane, urea, 2,2-bis(4-aminocyclohexyl)propane, 3-amino-1-(methylamino)propane, 3-amino-1-(cyclohexylamino)propane and N-(2-hydroxyethyl)ethylenediamine, polyetheramines, amide group-containing aliphatic polyamines and mixtures of two or more thereof.

[0064] Most preferably, the amino compound is selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), oligomerized polyetheramines and amide group-containing aliphatic polyamines, in particular the compounds (b) used in the examples.

[0065] As the amino compound (b), one compound (b) or a mixture of two or more different compounds (b) can be used.

[0066] The compound (b) having at least two amino groups is preferably present in the intumescent composition in an amount of 0.8 to 4.0 wt.%, preferably 1.5 to 3.5 wt.%, and more preferably 2.0 to 3.0 wt.%, based on the total weight of the composition. If a mixture of compounds (b) having at least two amino groups is used, these amounts refer to the mixture.

[0067] Intumescent additives (c-1)

[0068] According to the invention, the composition contains intumescent additives, so-called insulating layer-forming additives, which may comprise both individual compounds and a mixture of several compounds.

[0069] Intumescent additives are preferably used that form an inflated, insulating layer made of flame-resistant material under the influence of heat. This layer protects the substrate from overheating and thus prevents or at least delays changes in the mechanical and static properties of load-bearing components due to heat. The formation of a voluminous, insulating layer, namely an ash layer, can be achieved through the chemical reaction of a mixture of correspondingly matched compounds that react with each other when exposed to heat. Such systems are known to those skilled in the art under the term chemical intumescence and can be used according to the invention.Alternatively, the voluminous, insulating layer can be formed by expanding a single compound, which releases gases upon exposure to heat without any chemical reaction between the two compounds. Such systems are known to those skilled in the art as physical intumescence and can also be used according to the invention. Both systems can be used individually or together in combination according to the invention.

[0070] The formation of an intumescent layer through chemical intumescence generally requires at least three components: a carbon source, a dehydrogenation catalyst, and a blowing agent, which in coatings are contained in a binder. When exposed to heat, the binder softens and the fire-retardant additives are released, allowing them to react with each other in the case of chemical intumescence or expand in the case of physical intumescence. Thermal decomposition of the dehydrogenation catalyst converts an acid into a catalyst for the carbonization of the carbon source or the binder. At the same time, the blowing agent thermally decomposes to form inert gases, which cause the carbonized (charred) material and, if present, the softened binder to expand, forming a voluminous, insulating foam.

[0071] In one embodiment of the invention in which the insulating layer is to be formed by chemical intumescence and in which the binder acts as a carbon framework former (carbon supplier), the intumescent additives comprise at least one acid former and at least one blowing agent. In a further embodiment of the invention in which the insulating layer is to be formed by chemical intumescence, the intumescent additives comprise at least one dehydrogenation catalyst (acid former), at least one blowing agent, and at least one inorganic framework former.

[0072] In particular, the components of the additive are selected so that they can develop synergism, with some of the compounds being able to perform multiple functions.

[0073] Suitable carbon sources include the compounds commonly used in intumescent fire protection formulations and known to those skilled in the art, such as starch-like compounds, e.g., starch and modified starch, and / or polyhydric alcohols (polyols), such as saccharides and polysaccharides, and / or a thermoplastic or thermosetting polymeric resin binder, such as a phenolic resin, a urea resin, a polyurethane, polyvinyl chloride, poly(meth)acrylate, polyvinyl acetate, polyvinyl alcohol, a silicone resin, and / or a rubber. Suitable polyols are polyols from the group consisting of sugar, pentaerythritol, dipentaerythritol, tripentaerythritol, polyvinyl acetate, polyvinyl alcohol, sorbitol, and polyoxyethylene / polyoxypropylene (EO-PO) polyols. Pentaerythritol, dipentaerythritol, or polyvinyl acetate are preferred.

[0074] It should be mentioned that the binder itself can also function as a carbon supplier in the event of a fire.

[0075] Suitable dehydrogenation catalysts or acid generators are the compounds commonly used in intumescent fire protection formulations and known to the person skilled in the art, such as a salt or an ester of an inorganic, non-volatile acid selected from sulfuric acid, phosphoric acid, or boric acid. Essentially, phosphorus-containing compounds are used, the range of which is very broad, as they span several oxidation states of phosphorus, such as phosphines, phosphine oxides, phosphonium compounds, phosphates, elemental red phosphorus, phosphites, and phosphates. Examples of phosphoric acid compounds include: monoammonium phosphate, diammonium phosphate, ammonium phosphate, ammonium polyphosphate, melamine phosphate,

[0076] Melamine resin phosphates, potassium phosphate, polyol phosphates such as pentaerythritol phosphate, glycerol phosphate, sorbitol phosphate, mannitol phosphate, dulcitol phosphate, neopentyl glycol phosphate, ethylene glycol phosphate,

[0077] Dipentaerythritol phosphate, and the like. A polyphosphate or an ammonium polyphosphate is preferably used as the phosphoric acid compound. Melamine resin phosphates are understood to mean compounds such as reaction products of Lamelite C (melamine-formaldehyde resin) with phosphoric acid. Examples of sulfuric acid compounds include ammonium sulfate, ammonium sulfamate, nitroaniline bisulfate, 4-nitroaniline-2-sulfonic acid, and 4,4-dinitrosulfanilamide, among others. Melamine borate is an example of a boric acid compound.

[0078] Suitable blowing agents are compounds commonly used in fire protection formulations and known to those skilled in the art, such as cyanuric acid or isocyanic acid and their derivatives, and melamine and their derivatives. These include cyanamide, dicyanamide, dicyandiamide, guanidine and its salts, biguanide, melamine cyanurate, cyanic acid salts, cyanic acid esters and amides, hexamethoxymethylmelamine, dimelamine pyrophosphate, melamine polyphosphate, and melamine phosphate. Hexamethoxymethylmelamine or melamine (cyanuric acid amide) is preferred.

[0079] Also suitable are components whose mode of action is not limited to a single function, such as melamine polyphosphate, which acts both as an acid generator and as a blowing agent. Further examples are described in GB 2 007 689 A1, EP 139 401 A1, and US Pat. No. 3,969,291 A1.

[0080] The intumescent additives (c-1) can be present in the composition in an amount of 30 to 70 wt.%, the amount depending essentially on the application form of the composition (spraying, brushing, etc.). To achieve the highest possible intumescence rate, the proportion in the overall formulation is set as high as possible. The proportion of the intumescent additives (c-1) in the overall formulation is preferably 35 to 70 wt.%, and particularly preferably 40 to 70 wt.%, based on the total weight of the intumescent composition.

[0081] Physically acting intumescent additives (c-2)

[0082] In one embodiment of the invention in which the insulating layer is formed by physical intumescence, the intumescent composition comprises at least one thermally expandable compound, such as a graphite intercalation compound, also known as expandable graphite, as a physically acting intumescent additive (c-2) (also physical intumescent additive (c-2)). This can also be incorporated into the binder.

[0083] Expandable graphite includes, for example, well-known intercalation compounds of SO X, NOx, halogen and / or strong acids in graphite are suitable. These are also referred to as graphite salts. Preference is given to expandable graphites which release SO2, SO3, NO and / or NO2 upon expansion at temperatures of, for example, 120 to 350°C. The expandable graphite can, for example, be in the form of platelets with a maximum diameter in the range of 0.1 to 5 mm. This diameter is preferably in the range 0.5 to 3 mm. Expandable graphites suitable for the present invention are commercially available. In general, the expandable graphite particles are uniformly distributed in the fire protection elements according to the invention. The concentration of expandable graphite particles can, however, also be varied in a point-like, pattern-like, planar and / or sandwich-like manner. In this regard, reference is made to EP 1489136 A1.

[0084] The physical intumescent additive (c-2) is preferably present in the intumescent composition in an amount of 30 to 70 wt.%, preferably 35 to 70 wt.%, and more preferably 40 to 70 wt.%, based on the total weight of the composition. If both the intumescent additives (c-1) and the physical intumescent additive (c-2) are present in the intumescent composition, both can be present together in an amount of 30 to 70 wt.%. Preferably, the proportion of the two intumescent additives (c-1) and (c-2) together in the overall formulation is 35 to 70 wt.%, and particularly preferably 40 to 70 wt.%, based on the total weight of the intumescent composition.

[0085] Additional ash crust stabilizers

[0086] In order to further stabilize or harden the ash crust formed in the event of a fire, an ash crust stabilizer or framework former can be added in addition to the intumescent additives and the plasticizer listed above.

[0087] Suitable ash crust stabilizers or framework formers are the compounds commonly used in fire protection formulations and known to the person skilled in the art, for example expandable graphite and particulate metals such as aluminum, magnesium, iron, and zinc. The particulate metal can be in the form of a powder, platelets, flakes, fibers, filaments, and / or whiskers, with the particulate metal in the form of powder, platelets, or flakes having a particle size of <50 μm, preferably from 0.5 to 10 μm. When using the particulate metal in the form of fibers, filaments, and / or whiskers, a thickness of 0.5 to 10 μm and a length of 10 to 50 μm is preferred.Alternatively or additionally, an oxide or a compound of a metal from the group comprising aluminum, magnesium, iron or zinc can be used as an ash crust stabilizer, in particular iron oxide, preferably iron trioxide, titanium dioxide, a borate, such as zinc borate and / or a glass frit made of low-melting glasses with a melting temperature of preferably at or above 400°C, phosphate or sulfate glasses, melamine polyzinc sulfates, ferroglasses or calcium borosilicates. The addition of such an ash crust stabilizer contributes to a significant stabilization of the ash crust in the event of a fire, since these additives increase the mechanical strength of the intumescent layer and / or prevent it from dripping off. Examples of such additives can also be found in US 4 442 157 A, US 3 562 197 A, GB 755 551 A and EP 138 546 A1.

[0088] Ash crust stabilizers such as melamine phosphate or melamine borate may also be included.

[0089] The ash crust stabilizer titanium dioxide is particularly preferred.

[0090] The additional ash crust stabilizers are preferably present in the intumescent composition in an amount of 7 to 15 wt.%, preferably 8 to 14 wt.% and more preferably 9 to 13 wt.%, based on the total weight of the composition.

[0091] Additive

[0092] Optionally, one or more reactive flame retardants can be added to the composition according to the invention. Such compounds are incorporated into the binder. An example within the meaning of the invention are reactive organophosphorus compounds, such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives, such as DOPO-HQ, DOPO-NQ, and adducts. Such compounds are described, for example, in S. V. Levchik, E. D. Weil, Polym. Int. 2004, 53, 1901-1929.

[0093] In addition to the insulating layer-forming additives, the composition may optionally contain conventional auxiliaries such as solvents, for example xylene or toluene, wetting agents, for example based on polyacrylates and / or polyphosphates, defoamers such as silicone defoamers, thickeners such as alginate thickeners, dyes, fungicides, flame retardants or various fillers such as vermiculite, inorganic fibers, quartz sand, glass microspheres, mica, silicon dioxide, mineral wool, and the like.

[0094] In addition to the additives mentioned, the composition may optionally contain conventional auxiliaries such as solvents, for example xylene or toluene, wetting agents, for example based on polyacrylates and / or polyphosphates, defoamers, such as silicone defoamers, thickeners, such as alginate thickeners, dyes, fungicides, flame retardants or various fillers, such as vermiculite, inorganic fibers, quartz sand, glass microspheres, mica, silicon dioxide, mineral wool, and the like.

[0095] Additional additives such as thickeners, rheology additives, and fillers can be added to the composition. Rheology additives such as anti-settling agents, anti-sagging agents, and thixotropic agents are preferably polyhydroxycarboxylic acid amides, urea derivatives, salts of unsaturated carboxylic acid esters, alkylammonium salts of acidic phosphoric acid derivatives, ketoximes, amine salts of p-toluenesulfonic acid, amine salts of sulfonic acid derivatives, as well as aqueous or organic solutions or mixtures of the compounds. Rheology additives based on pyrogenic or precipitated silicas, or based on silanized pyrogenic or precipitated silicas, can also be used.The rheology additive preferably comprises pyrogenic silicas, modified and unmodified phyllosilicates, precipitated silicas, cellulose ethers, polysaccharides, PU and acrylate thickeners, urea derivatives, castor oil derivatives, polyamides and fatty acid amides and polyolefins, provided they are in solid form, powdered celluloses and / or suspending agents such as xanthan gum.

[0096] The additional additives may be added to the intumescent composition in a total amount, i.e. all additives together, of 0.2 to 3.0 wt.%, based on the total weight of the composition.

[0097] The composition according to the invention can be formulated as a two- or multi-component system.

[0098] The individual components of the intumescent composition are distributed among the components in such a way that no reaction can occur during storage that would impair the storage capacity of the system.

[0099] In a preferred embodiment of the invention, the composition according to the invention is formulated as a two-component system, wherein the at least one compound (a) and the at least one compound (b) are arranged separately to inhibit the reaction and thus divided into two components to inhibit the reaction. Accordingly, a first component, component I, contains the compound (a), and a second component, component II, contains the at least one compound (b).

[0100] The intumescent additive can be contained as a complete mixture or divided into individual components in one or more components. The distribution depends on the compatibility of the compounds contained in the composition, so that the compounds contained in the composition cannot react with each other or interfere with each other. This depends on the compounds used. This ensures that the highest possible filler content can be achieved. This leads to high intumescence, even with thin layers of the composition. If the composition also contains an ash crust stabilizer, this is distributed among the components in such a way that one of the components contains at least a portion of the ash crust stabilizer and the other component optionally contains a further portion of the ash crust stabilizer.

[0101] The composition is applied as a paste to the substrate, especially a metallic substrate, using a brush, roller, or spraying. The composition is preferably applied using an airless spraying method.

[0102] Compared to solvent- and water-based systems, the composition according to the invention is characterized by rapid curing through an addition reaction, thus eliminating the need for drying. This is particularly important when the coated components must be subjected to rapid loading or further processing, whether by coating with a topcoat or moving or transporting the components. The coating is thus also significantly less susceptible to external influences on the construction site, such as exposure to (rain)water or dust and dirt, which in solvent- or water-based systems can lead to the leaching of water-soluble components such as ammonium polyphosphate, or to reduced intumescence when absorbing dust.The low viscosity of the composition despite the high solids content makes it easy to process, especially using common spraying methods. Due to the low softening point of the binder and the high solids content, the expansion rate upon exposure to heat is high, even at low layer thicknesses.

[0103] Therefore, the two- or multi-component composition according to the invention is suitable as a coating, in particular as a fire protection coating, preferably a sprayable coating, for metallic and non-metallic substrates. The substrates are not limited and include components, in particular steel components and wooden components, but also individual cables, cable bundles, cable trays, cable ducts, or other lines.

[0104] The composition according to the invention is used primarily in the construction sector as a coating, in particular fire protection coating for steel construction elements, but also for construction elements made of other materials, such as concrete or wood, as well as as a fire protection coating for individual cables, cable bundles, cable trays and cable ducts or other lines.

[0105] A further object of the invention is therefore the use of the composition according to the invention as a coating, in particular as a coating for construction elements or building elements made of steel, concrete, wood and other materials, such as plastics, in particular as a fire protection coating.

[0106] The present invention also relates to objects obtained when the composition according to the invention has cured. These objects have excellent insulating properties.

[0107] The following examples serve to further illustrate the invention.

[0108] The following components were used in the examples:

[0109] To produce the intumescent compositions according to the invention, the individual components (Example 1 and Example 2) were mixed and homogenized using a dissolver as described below. The time to failure (TTF) and hardness of the ash crust were determined as described below. Furthermore, the structure of the ash crust was assessed visually. Determination of TTF

[0110] The TTF was determined using fire tests in a plate test furnace. The steel plates coated with the intumescent material are exposed to a flame using a standard temperature curve (ETC). Before the starting point t = 0 min, the temperature is monitored at several points on the back of the plate. If the average of the three thermal sensors reaches the critical temperature (EN = 550 °C, ASTM = 538 °C), the time period is considered the achieved resistance at the defined coating thickness.

[0111] Determination of the hardness of the ash crust

[0112] The hardness and stability of the ash crust are determined primarily through visual and manual analysis. Cross-sections of the ash crust are also cut to determine the cellular structure of the ash.

[0113] Example 1 :

[0114] 1) Quantity see Table 1 Table 1 : Results of the determination of TTF, hardness and assessment of the

[0115] Ash structure of the formulations according to Example 1 Example 2:

[0116] 2) see Table 2

[0117] Table 2: Results of the determination of TTF, hardness and assessment of the

[0118] Ash structure of the formulations according to Example 2

Claims

PATENT CLAIMS 1. Intumescent composition containing (a) at least one compound having at least two epoxide groups, (b) at least one compound having at least two amino groups which can react with the epoxide groups, (c-1) Intumescent additives selected from the group consisting of blowing agent and dehydrogenation catalyst and combinations thereof and / or (c-2) a thermally expandable compound and (d) at least one plasticizer, wherein the cured composition forms an insulating layer in the event of fire.

2. Intumescent composition according to claim 1, wherein the plasticizer is selected from the group consisting of derivatives of benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, phosphoric acid and citric acid, alkyl phosphate esters and derivatives of polyesters, polyethers and epoxides, C10-C2i-alkylsulfonic acid esters of phenol, polyesters obtainable from linear or branched, saturated or unsaturated C6-C2i-monocarboxylic acids and multifunctional alcohols and their ethoxylated derivatives, and alicyclic carboxylic acid esters and mixtures of two or more thereof.

3. The intumescent composition of claim 2, wherein the plasticizer is selected from the group consisting of phosphoric acid esters, citrate esters and phthalates.

4. Intumescent composition according to claim 3, wherein the plasticizer is 1,2-cyclohexanedicarboxylic acid diisononyl ester.

5. Intumescent composition according to one of the preceding claims, in which the plasticizer is present in a proportion of 2% to 10% by weight, based on the total weight of the intumescent composition.

6. Intumescent composition according to any one of the preceding claims, wherein the intumescent additives (c-1) further comprise a carbon supplier 7. Intumescent composition according to one of the preceding claims, wherein the at least one compound having at least two amino groups is selected from the group consisting of ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, decamethylenediamine, 4,7-dioxadecane-1,10-diamine, dodecamethylenediamine, 4,9-dioxadodecane-1,12-diamine, 7-methyl-4,10-dioxatridecane-1,13-diamine, 1,2-diaminocyclohexane, 1,4- Diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,2-bis(aminomethyl)cyclohexane (1,2-BAC), hexamethylenediamine (HMD), 1,2- and 1,4-diaminocyclohexane (1,2-DACH and 1,4-DACH), isophoronediamine, bis(3-methyl-4-aminocyclohexyl)methane, urea, 2,2-bis(4-aminocyclohexyl)propane, 3-amino-1-(methylamino)propane, 3-amino-1-(cyclohexylamino)propane and N-(2-hydroxyethyl)ethylenediamine, polyetheramines, amide group-containing aliphatic polyamines and mixtures of two or more thereof.

8. Intumescent composition according to any one of the preceding claims, wherein the blowing agent is selected from the group consisting of cyanuric acid, isocyanic acid and derivatives thereof, melamine and derivatives thereof, and combinations thereof.

9. An intumescent composition according to any one of the preceding claims, wherein the dehydrogenation catalyst is selected from the group consisting of a salt or an ester of an inorganic, non-volatile acid selected from sulfuric acid, phosphoric acid or boric acid, and combinations thereof. An intumescent composition according to any one of the preceding claims, wherein the carbon source is selected from the group consisting of starch, modified starch, polyhydric alcohols, thermoplastic or thermosetting polymeric resin binders, and combinations thereof. An intumescent composition according to any one of the preceding claims, wherein the thermally expandable compound is selected from graphite intercalation compounds and vermiculites, in particular graphite intercalation compounds. Use of a plasticizer in an intumescent composition to improve the stability and structure of the ash crust, thereby improving the insulating effect of an ash crust formed from the intumescent composition in the event of a fire.Use according to claim 12, wherein the plasticizer is selected from the group consisting of derivatives of benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, phosphoric acid, and citric acid, alkyl phosphate esters and derivatives of polyesters, polyethers, and epoxides, C10-C21-alkylsulfonic acid esters of phenol, polyesters obtainable from linear or branched, saturated or unsaturated C6-C21 monocarboxylic acids and polyfunctional alcohols and their ethoxylated derivatives, and alicyclic carboxylic acid esters, as well as mixtures of two or more thereof. Use according to claim 13, wherein the plasticizer is 1,2-cyclohexanedicarboxylic acid diisononyl ester. Use according to any one of claims 12 to 14, wherein the plasticizer is present in the intumescent composition in an amount of about 2% to about 10% by weight, based on the total weight of the intumescent composition.

16. Use of an intumescent composition according to one of claims 1 to 11 for coating components, in particular as a fire protection coating.

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