Polysiloxane-based intumescent coating composition

Abstract

The present invention relates to a polysiloxane-based intumescent coating composition comprising a) a polysiloxane-based binder system comprising i) one or more epoxy-functional polysiloxanes, and b) one or more catalysts. The a) polysiloxane-based binder system may additionally comprise i i) one or more amino-functional polysiloxanes. The invention also relates to the use of the coating composition according to the invention for coating the surface of a substrate. The invention also relates to a substrate, preferably a steel substrate, having, on the surface thereof, a coating obtained from the coating composition according to the invention. The invention also relates to a multi-part kit for preparing the polysiloxane-based intumescent coating composition.

Description

Technical Field

[0001] The present invention relates to a novel polysiloxane-based intumescent coating composition. The present invention also relates to the use of the coating composition of the present invention for application to a substrate surface. The present invention also relates to a substrate, preferably a steel substrate, having a coating obtained from the coating composition of the present invention on its surface. The present invention also relates to a multi-part kit for preparing a polysiloxane-based intumescent coating composition. Background Art

[0002] The present invention relates to an intumescent coating composition and its use for protecting building structures, as well as a substrate coated with said composition.

[0003] Many materials, such as steel, quickly lose strength and fail in a fire. Fire-induced structural collapse of a "high-rise" office building, oil and gas facility or other infrastructure, as well as rupture of process vessels or pipelines can have catastrophic consequences in terms of escalation, property damage and even loss of life.

[0004] Buildings with steel frames are particularly susceptible to collapse in the event of a fire. As temperatures rise, steel loses strength. By providing an intumescent coating on the steel, the rate of heat transfer can be reduced, allowing the building to remain intact longer, providing more time for evacuation.

[0005] ED Weil, "Fire-Protective and Flame-Retardant Coatings-A State-of-the-Art Review," Journal of Fire Sciences (2011), 29(3): 259-296, describes various intumescent coatings used to protect substrates from fire damage. Intumescent coatings are used on many building structures to delay the effects of fire. The coatings slow the rate at which the temperature of the substrate to which the coating is applied rises and prolong the time before the building structure fails due to the heat of the fire. This additional time makes it more likely that firefighters will be able to extinguish the fire or at least allow the use of cooling water before the building structure fails. Intumescent coatings expand when heated, significantly extending the time before the substrate is damaged by fire.

[0006] The intumescent coating composition itself comprises an intumescent component, including a component selected from an acid generating compound, an intumescent agent and a carbon source (which may be contained in the binder system or may be an added compound).

[0007] When the intumescent coating is exposed to fire or heat and the temperature of the coating is, for example, greater than 200°C, the acid-generating compound decomposes to produce acid, and the carbon source reacts with the acid to form carbonaceous char. The intumescent agent also decomposes at high temperatures (e.g., greater than 200°C) and produces additional gas, which expands the volume of the carbonaceous char and produces carbonaceous foam.

[0008] The intumescent coating composition may comprise a one-component or two-component binder system. A typical intumescent coating composition is an epoxy-based binder system, see, for example, WO2021 / 250211. A variety of other binder systems can also be used in intumescent coating compositions, for example WO2010 / 131037 discloses an intumescent coating composition based on a binder system having a silane-terminated polyurethane or a silane-terminated ether; US2020 / 157361 discloses a binder based on a polymer with an alkoxysilane group. Intumescent coating compositions based on a binder system comprising polysiloxanes are also known in the art. For example, WO2005 / 078012 and WO2010 / 054984 disclose intumescent coating compositions comprising a combination of polysiloxanes and organic resins. SUMMARY OF THE INVENTION

[0010] The present invention provides a novel polysiloxane-based intumescent coating composition, which can provide a coating having excellent fire retardant properties and good hardness development.

[0011] The present invention therefore relates to an intumescent coating composition comprising:

[0012] a) a polysiloxane-based binder system comprising: i) one or more epoxy-functional polysiloxanes; and

[0013] b) one or more catalysts.

[0014] The binder system a) may additionally comprise ii) one or more amino-functional polysiloxanes.

[0015] In one aspect, the present invention relates to a multi-part kit suitable for formulating an intumescent coating composition comprising a polysiloxane-based binder system, wherein the kit comprises:

[0016] A) a container containing one or more epoxy-functional polysiloxanes; and

[0017] B) A container containing one or more catalysts.

[0018] In one aspect, the present invention relates to a multi-part kit suitable for formulating an intumescent coating composition comprising a polysiloxane-based binder system, wherein the kit comprises:

[0019] A1) a container containing one or more epoxy-functional polysiloxanes; and

[0020] A2) a container containing one or more amino-functional polysiloxanes; and

[0021] in:

[0022] The container A1) also contains one or more catalysts, and / or

[0023] The container A2) also contains one or more catalysts, and / or

[0024] The kit further comprises B) a container containing one or more catalysts.

[0025] In one aspect, the present invention relates to the use of the intumescent coating composition of the present invention for application to the surface of a substrate, such as a metal substrate.

[0026] In one aspect, the present invention relates to a substrate, preferably a metal substrate or a metal alloy substrate, such as a steel substrate, having on at least a portion of its surface a coating obtained from the coating composition of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention relates to a novel intumescent coating composition which is suitable for application to a number of different surfaces, thereby providing a coating having excellent fire protection properties and very good hardness development within a relatively short curing time.

[0029] Preferably, the intumescent coating composition is a liquid, ambient-curable coating composition, ie a liquid coating composition capable of curing under ambient conditions / temperatures, such as between -5°C and 50°C, such as 5-40°C at 50% relative humidity.

[0030] The intumescent coating composition comprises a binder system, one or more catalysts, an intumescent package, and may also comprise fibers and "conventional" coating additives, fillers, pigments and solvents. The intumescent coating composition of the present invention is a polysiloxane-based coating composition, which means that the binder system comprises more than 50 wt%, such as more than 55 wt%, such as more than 60 wt% or more than 65 wt% of polysiloxane, and preferably more than 70 wt%, such as more than 75 wt% or 80 wt% or 85 wt% or 90 wt% or 95 wt% of polysiloxane, based on the total weight of the binder system, for example about 100 wt% of polysiloxane, based on the total weight of the binder system. In the context of the present invention, the polysiloxane-based binder system comprises one or more epoxy-functional polysiloxanes and optionally one or more amino-functional polysiloxanes.

[0031] Thus, the present invention relates to an intumescent coating composition comprising a binder system comprising one or more epoxy functional polysiloxanes. In one embodiment, the binder system further comprises one or more amino functional polysiloxanes. It is to be understood that when only epoxy functional polysiloxanes are present, curing will be by homopolymerization of epoxy groups, whereas when amino functional polysiloxanes are present, crosslinking will occur between the amino functional polysiloxane and the epoxy functional polysiloxane, and there may also be a certain degree of homopolymerization between the epoxy functional polysiloxanes.

[0032] The claimed intumescent coating composition provides a coating that is very effective in fire protection properties. The inventors have found that typical failure times measured at 550°C are in the range of 75-150 minutes.

[0033] Comparative coatings obtained from compositions containing only 100% organic epoxy binder were fire resistant only for 45-65 minutes (Comparative coatings A, B, C and D in Table 6).

[0034] The substrate to be coated can consist of a single material, for example a metal or a metal alloy, preferably steel or iron. The substrate can also consist of a combination of several materials.

[0035] The claimed intumescent coating composition can be used for various types of fire protection, including, for example, cellulose fire protection, hydrocarbon fire protection, low temperature fire protection, jet fire protection, pool fire protection, and hydrogen fire protection. In one embodiment, the intumescent coating composition is used for cellulose fire protection and / or hydrocarbon fire protection. In one embodiment, the intumescent coating composition is used for both cellulose and hydrocarbon fire protection.

[0036] The claimed intumescent coating composition can be used to coat substrates, such as steel substrates used to form building frames either off-site (during the steel preparation process) or on-site (after the steel frame is laid in place at the building site).

[0037] The term "coating composition" means a mixed liquid composition comprising all ingredients, which can be applied directly to a substrate.

[0038] As used herein, the term "coating" means a coating obtained by applying a coating composition to a surface and curing the composition (may also be expressed as a "cured coating").

[0039] The coating may be obtained by applying one or more layers of the coating composition to obtain a cured coating of the desired thickness.

[0040] In one embodiment, the intumescent coating composition comprises:

[0041] a) a polysiloxane-based binder system comprising i) one or more epoxy-functional polysiloxanes; and

[0042] b) one or more catalysts.

[0043] In a further embodiment, the a) polysiloxane-based binder system further comprises ii) one or more amino-functional polysiloxanes.

[0044] In a further embodiment, the intumescent coating composition further comprises c) an intumescent package.

[0045] In one embodiment, the intumescent coating composition comprises:

[0046] a) a polysiloxane-based binder system comprising i) one or more epoxy-functional polysiloxanes; and ii) one or more amino-functional polysiloxanes; and

[0047] b) one or more catalysts.

[0048] In a further embodiment, the coating composition further comprises c) an intumescent package.

[0049] In one embodiment, the intumescent coating composition comprises:

[0050] a) a polysiloxane-based binder system comprising i) one or more epoxy-functional polysiloxanes;

[0051] b) one or more catalysts; and

[0052] c) Expansion pack.

[0053] In one embodiment, the intumescent coating composition comprises:

[0054] a) a polysiloxane-based binder system comprising i) one or more epoxy-functional polysiloxanes, and ii) one or more amino-functional polysiloxanes;

[0055] b) one or more catalysts; and

[0056] c) Expansion pack.

[0057] The polysiloxane-based binder system in the intumescent coating composition of the present invention comprises more than 50 wt% polysiloxane, such as more than 55 wt%, such as more than 60 wt% or 60 wt%, preferably more than 70 wt%, such as more than 75 wt% or 80 wt% or 85 wt% or 90 wt% or 95 wt% polysiloxane, based on the total weight of the binder system, for example about 100 wt% polysiloxane based on the total weight of the binder system.

[0058] Binder system

[0059] The term "binder system" of the coating composition refers to the components of the coating composition that are capable of polymerizing to form a binder matrix when cured. As described above, the polysiloxane-based binder system in the claimed coating composition comprises one or more epoxy-functional polysiloxanes and may optionally comprise one or more amino-functional polysiloxanes.

[0060] The term "polysiloxane" is known in the art and is defined as a polysiloxane having a repeating silicon-oxygen backbone (Si-O) n Polymers wherein each Si atom is substituted by two organic groups. Typically, the organic substituents on each Si atom are identical and may be selected, for example, from alkyl groups (e.g., methyl or ethyl) or phenyl groups. A particularly typical polysiloxane is polydimethylsiloxane (PDMS). In the context of the present invention, linear and branched polysiloxanes are included. Preferably, linear polysiloxanes are used.

[0061] The terms "epoxy-functional polysiloxane" and "amino-functional polysiloxane" are common terms related to polysiloxane chemistry. "Epoxy-functional polysiloxane" refers to polysiloxanes having at least one reactive epoxy functional group attached via a carbon bond (i.e. not directly on a Si atom) in a terminal and / or pendant position, while "amino-functional polysiloxane" refers to polysiloxanes having at least one reactive amine attached via a carbon bond in a terminal and / or pendant position. The amine is selected from primary amines and secondary amines. In the context of the present invention, there must be at least one primary amino functional group, or at least two secondary amino functional groups, or at least one primary amino functional group and at least one secondary amino functional group.

[0062] The inventors have found that the fire retardant properties are excellent when the intumescent coating is obtained only by epoxy-epoxy homopolymerization and when it contains amine groups (Tables 1, 2 and 3). However, when an amino-functional polysiloxane is present in the coating composition, crosslinking between the active hydrogens of the epoxy groups and the amine groups can occur, thereby improving the hardness development. Therefore, the stoichiometry between the active hydrogens of the amino groups relative to the epoxy groups can be adjusted to obtain a better hardness development. Therefore, in one embodiment, the binder system comprises the epoxy-functional polysiloxane and the amino-functional polysiloxane in an amount such that the stoichiometry of the active hydrogens of the amine groups relative to the epoxy groups is at least 5%, preferably at least 10%, more preferably at least 15%, such as at least 20%, such as at least 25%, such as at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, such as about 100%.

[0063] The stoichiometry between the active hydrogens of the amino group and the epoxy groups is the ratio of active hydrogens on the amino group to epoxy groups, expressed as a percentage. It is calculated by dividing the total number of active hydrogens by the total number of epoxy groups and then multiplying this value by 100. Thus, for example, a stoichiometry of 50% means that the number of active hydrogens corresponds to 50% of the number of epoxy groups. Primary amines contain two active hydrogens, secondary amines contain one active hydrogen, and tertiary amines contain no active hydrogens.

[0064] The intumescent coating composition may be prepared from a variety of different combinations of epoxy functional polysiloxanes. When one or more amino functional polysiloxanes are present, the coating composition may be prepared from a variety of different combinations of epoxy functional polysiloxanes and amino functional polysiloxanes.

[0065] If any alkoxy groups are present on the epoxy-functional polysiloxane backbone and / or the amino-functional polysiloxane backbone, the alkoxy groups are preferably present in an equivalent ratio of alkoxy groups to epoxy groups of 0:100 to 5:100. In a preferred embodiment, the epoxy-functional polysiloxane and / or the amino-functional polysiloxane does not have any alkoxy groups attached to the polysiloxane backbone. In one embodiment, both the epoxy-functional polysiloxane and the amino-functional polysiloxane do not have any alkoxy groups attached to the polysiloxane backbone.

[0066] In one embodiment, the epoxy-functional polysiloxane does not have any condensable or hydrolyzable groups attached to the polysiloxane backbone.

[0067] In a preferred embodiment, the epoxy-functional polysiloxane and / or the amino-functional polysiloxane do not have any reactive groups other than the epoxy-functional groups and the amino-functional groups. In a further embodiment, both the epoxy-functional polysiloxane and the amino-functional polysiloxane do not have any reactive groups other than the epoxy-functional groups and the amino-functional groups.

[0068] Epoxy functional polysiloxane

[0069] The term "epoxy-functional polysiloxane" is to be understood in the conventional sense and refers to a polysiloxane having at least one epoxy-functional group attached via a carbon bond at a terminal and / or pendant position.

[0070] Epoxy functional groups can be introduced into polysiloxanes, for example, via epoxy silanes or epoxy resins, see, for example, EP1086974A. In one example thereof, epoxy functional polysiloxanes are prepared by reaction between epoxy resins and reactive polysiloxanes, optionally with the simultaneous action of other ingredients (e.g., ingredients with hydroxyl and / or alkoxy groups, etc.). In another example, epoxy functional polysiloxanes can be prepared by partial hydrolysis and condensation of epoxy silane and alkoxy silane mixtures. It should be understood that epoxy functional polysiloxanes can be prepared in situ, if desired.

[0071] In order to achieve homopolymerization of epoxy groups, one epoxy functional group on each polysiloxane is sufficient, while crosslinking with amino-functional polysiloxanes requires the presence of polysiloxanes with at least two epoxy functional groups. Therefore, in one embodiment, the one or more epoxy-functional polysiloxanes have at least one epoxy functional group. In a further embodiment, the one or more epoxy-functional polysiloxanes have at least two epoxy functional groups. In a further embodiment, the binder system comprises i) one or more epoxy-functional polysiloxanes, and ii) one or more amino-functional polysiloxanes, wherein the one or more epoxy-functional polysiloxanes have at least two epoxy functional groups.

[0072] In one embodiment, the epoxy-functional polysiloxane is represented by the following formula (I) and has a molecular weight in the range of 200-500,000 g / mol:

[0073]

[0074] in:

[0075] n+m+p is an integer between 2 and 7500,

[0076] Each R1 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C 30 Alkenyl, C3-C 30 Cycloalkyl and aryl groups,

[0077] Each R2 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C 30 Alkenyl, C3-C 30 cycloalkyl and aryl, and substituted with at least one epoxy functional group, and

[0078] Each R3 is independently selected from Si(R1)3 or Si(R1)2R2 or Si(R1)(R2)2 or Si(R2)3;

[0079] Provided that the epoxy-functional polysiloxane has at least one epoxy functional group.

[0080] In one embodiment, the epoxy-functional polysiloxane has at least two epoxy functional groups.

[0081] In one embodiment, the molecular weight of the compound of formula (I) is in the range of 500-500,000 g / mol, for example 1000-500,000 g / mol, for example 1000-100,000 g / mol, 5000-100,000 g / mol or 5000-50,000 g / mol.

[0082] In one embodiment, at least one R3 is Si(R1)2R2 or Si(R1)(R2)2 or Si(R2)3, preferably Si(R1)2R2.

[0083] In another embodiment, both R3 are Si(R1)3.

[0084] In one embodiment, (n+m+p) is an integer of 5-5000, such as 5-4000, such as 5-3000, such as 5-2000, preferably 5-1000, more preferably 20-1000 or 20-500; and (m+p) is an integer of 1-40, such as 1-30, such as 1-20, such as 1-10.

[0085] In a further embodiment, (n+m+p) is an integer of 5-5000, for example 5-4000, for example 5-3000, for example 5-2000, preferably 5-1000, more preferably 20-1000 or 20-500; and (m+p) is an integer of 1-40, for example 1-30, for example 1-20, for example 1-10, and both R3 are Si(R1)3.

[0086] In a further embodiment, (n+m+p) is an integer of 5-5000, for example 5-4000, for example 5-3000, for example 5-2000, preferably 5-1000, more preferably 20-1000 or 20-500; and (m+p) is an integer of 0-40, for example 0-30, for example 0-20, for example 0-10, and at least one R3 is Si(R1)2R2 or Si(R1)(R2)2 or Si(R2)3, preferably Si(R1)2R2.

[0087] In one embodiment, each R1 is independently selected from a linear or branched C1-C6 alkyl, a linear or branched C2-C6 alkenyl, a C3-C6 cycloalkyl and an aryl. In a further embodiment, each R1 is independently selected from a linear or branched C1-C3 alkyl, a linear or branched C2-C3 alkenyl, a cyclopropyl and a phenyl. In one embodiment, all side chains R1 are selected from methyl or phenyl. In a further embodiment, all R1 are selected from methyl or phenyl. In a preferred embodiment, all R1 are methyl.

[0088] In one embodiment, each R2 is independently selected from a linear or branched C1-C 10 Alkyl, linear or branched C2-C 10 Alkenyl, C3-C 10 In one embodiment, each R2 is selected from a linear or branched C1-C3 alkyl, a linear or branched C2-C3 alkenyl, a cyclopropyl or an aryl, and is substituted by at least one epoxy functional group. In a preferred embodiment, all R2 are 1-propyl substituted by an epoxy functional group.

[0089] The term "epoxy functional group" refers to a monovalent organic group containing an oxirane ring.

[0090] As used herein, the term "monovalent organic group" refers to a group containing carbon and having only one bonding site.

[0091] The epoxy functional group may include compounds selected from the following non-exhaustive list of structural formulae:

[0092]

[0093] In a preferred embodiment, the epoxy functional group is represented by the formula:

[0094]

[0095] In a preferred embodiment, R2 is

[0096] Commercial examples of epoxy functional polysiloxanes include, for example, GP-607 and GP-554 from Genesee Polymers and DMS-E11 and DMS-E12 from Gelest.

[0097] Amino functional polysiloxane

[0098] The binder system may additionally comprise one or more amino-functional polysiloxanes.

[0099] In the context of this article, the term "amino-functional polysiloxane" refers to a polysiloxane having at least one primary amino functional group, or at least two secondary amino functional groups, or at least one primary amino functional group and at least one secondary amino functional group. The amino functional group can be connected to the terminal and / or side chain position of the polysiloxane through a carbon bond.

[0100] The amino functional groups can be introduced into the reactive polysiloxane, for example, by aminosilanes (i.e., such as those defined below), see, for example, US 4,857,608. It should also be understood that the amino functional polysiloxane can be prepared in situ. In some examples, a hydroxyl functional or alkoxy functional polysiloxane is reacted with an aminosilane to introduce the amino functional groups. For example, an aminosilane can be reacted with an α,ω-dihydroxy polydimethylsiloxane at a temperature of 20-80° C., preferably, 0.4-1.2 alkoxy groups of the aminosilane are used relative to each silanol group of the polysiloxane. If an excess of aminosilane is used, or the reaction cannot be carried out to completion, a small amount of aminosilane may remain in the product. In one embodiment, at least one amino functional polysiloxane is the reaction product of a polysiloxane and an aminosilane.

[0101] In one embodiment, the amino-functional polysiloxanes contain no hydrolyzable and / or condensable groups, such as, for example, hydroxyl, alkoxy, acyloxy, ketoimino, alkoxy and / or alkenyloxy groups.

[0102] In order to crosslink with epoxy functional polysiloxane, at least two active hydrogens are required on the amino functional polysiloxane. Therefore, the amino functional polysiloxane must contain at least one primary amino functional group, or at least two secondary amino functional groups, or at least one primary amino functional group and at least one secondary amino functional group.

[0103] In one embodiment, the amino-functional polysiloxane is represented by the following formula (II) and has a molecular weight in the range of 200-500,000 g / mol:

[0104]

[0105] in:

[0106] q+r+s is an integer between 2 and 7500,

[0107] Each R4 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C 30 Alkenyl, C3-C 30 cycloalkyl or aryl, and

[0108] Each R5 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C30 Alkenyl, C3-C 30 cycloalkyl and aryl, and substituted with at least one amino functional group; and

[0109] Each R6 is independently selected from Si(R4)3 and Si(R4)2R5 and SiR4(R5)2 and Si(R5)3;

[0110] Provided that the amino-functional polysiloxane has at least one primary amino-functional group, or at least two secondary amino-functional groups, or at least one primary amino-functional group and at least one secondary amino-functional group.

[0111] In one embodiment, the amino-functional polysiloxane has at least one primary amino functional group. In one embodiment, the amino-functional polysiloxane has at least two secondary amino functional groups. In one embodiment, the amino-functional polysiloxane has at least one primary amino functional group and at least one secondary amino functional group.

[0112] In one embodiment, the molecular weight of the compound of formula (II) is in the range of 500-500,000 g / mol, for example 1000-500,000 g / mol, for example 1000-100,000 g / mol, 5000-100,000 g / mol or 5000-50,000 g / mol.

[0113] In one embodiment, both R6 are Si(R4)3. In another embodiment, at least one R6 is Si(R4)2R5 or Si(R4)(R5)2 or Si(R5)3, preferably Si(R4)2R5.

[0114] In one embodiment, (q+r+s) is an integer of 5-5000, such as 5-4000, such as 5-3000, such as 5-2000, preferably 5-1000, more preferably 20-1000 or 20-500; and (r+s) is an integer of 1-40, such as 1-30, such as 1-20, such as 1-10.

[0115] In a further embodiment, (q+r+s) is an integer of 5-5000, for example 5-4000, for example 5-3000, for example 5-2000, preferably 5-1000, more preferably 20-1000 or 20-500; and (r+s) is an integer of 1-40, for example 1-30, for example 1-20, for example 1-10; and both R6 are Si(R4)3.

[0116] In a further embodiment, (q+r+s) is an integer of 5-5000, for example 5-4000, for example 5-3000, for example 5-2000, preferably 5-1000, more preferably 20-1000 or 20-500; and (r+s) is an integer of 0-40, for example 0-30, for example 0-20, for example 0-10; and at least one R6 is Si(R4)2R5 or Si(R4)(R5)2 or Si(R5)3, preferably Si(R4)2R5.

[0117] In one embodiment, each R4 is independently selected from a linear or branched C1-C6 alkyl, a linear or branched C2-C6 alkenyl, a C3-C6 cycloalkyl and an aryl. In a further embodiment, each R4 is independently selected from a linear or branched C1-C3 alkyl, a linear or branched C2-C3 alkenyl, a cyclopropyl and a phenyl. In one embodiment, all side chains R4 are selected from methyl or phenyl. In a further embodiment, all R4 are selected from methyl or phenyl. In a preferred embodiment, all R4 are methyl.

[0118] In one embodiment, R5 is selected from a linear or branched C1-C3 alkyl group, a linear or branched C2-C 30 alkenyl, cyclopropyl and aryl, and is substituted with at least one amino functional group.

[0119] In a preferred embodiment, all R5 are 1-propyl substituted by an amino functional group. In a further preferred embodiment, all R5 are 1-propyl substituted by a substituent selected from -NH2 or -NH-CH2-CH2-NH2.

[0120] Commercially available amino-functional polysiloxanes include, for example, Dowsil 3055 from Dow, GP-4 from Genesee Polymers, and Sil Amine AO-EDA from Siltech.

[0121] Other components in the binder system

[0122] The binder system may also include a certain amount of organic resins, such as polymers in which most of the polymer backbone is based on carbon-carbon bonds. The term "organic resin" refers to a resin of organic nature, which may contain heteroatoms, but does not contain polymeric or oligomeric polysiloxanes, siloxanes or silicate moieties. However, the organic resin may contain alkoxysilyl functional groups. Particular mention is made of epoxy resins, polyamides, nylons, polyesters, ABS combinations, halogenated polymers such as polyvinyl chloride (PVC), polyethylene, polypropylene, polyurethane, polyacrylate / polymethacrylate (homopolymers and copolymers), polystyrene, polypropylene chloride, phenolic resins and their copolymers. Particular mention is made of organic epoxy resins and amino resins.

[0123] The inventors have found that the amount of organic resin in the binder system increases and has a negative impact on the failure time (Table 4). Therefore, in a preferred embodiment, the content of any organic resin in the binder system is less than 50wt%, such as less than 40wt%, such as less than 30wt%, preferably less than 20wt%, such as less than 15wt% or 10wt% or 5wt%, based on the weight of the binder system. In one embodiment, the binder system does not include any added organic resin, which means that there is no organic resin or organic polymer in the binder system except for trace organic resin or organic polymer that may be present in commercial polysiloxanes. In one embodiment, the coating composition itself does not include any organic resin.

[0124] catalyst

[0125] The coating composition also includes one or more catalysts to allow and / or accelerate the formation of the binder system.

[0126] Surprisingly, the inventors have found that the presence of one or more catalysts in the coating composition also has a significant impact on the fire resistance of the coating. If there is no catalyst in the composition, the expiration time is only about 40-65 minutes (Table 5). In addition, the selection of one or more catalysts seems to have an impact on the fire resistance.

[0127] One or more catalysts can be selected from compounds known to be used as catalysts in epoxy-epoxy reactions and / or epoxy-amine reactions. In one embodiment, one or more catalysts are suitable for catalyzing epoxy-epoxy reactions, amine-epoxy reactions, or epoxy-epoxy and amine-epoxy reactions. Suitable catalysts include, but are not limited to, nucleophilic catalysts such as tertiary amines, phosphines and imidazoles and other heterocyclic compounds, Bronsted acids and Lewis acids such as alcohols, phenol derivatives such as fluorophenol and nitrophenol, water, organic acids and inorganic acids. Other catalysts include metal salts, metal halides and trifluoromethanesulfonates, and substances that can decompose in strong acids, bases or nucleophiles after applying external stimuli (such as ultraviolet light or redox processes), such as photoinitiators.

[0128] In one embodiment, the one or more catalysts include phenols, such as phenol, 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, fluorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol, 2,4,6-tris-(dimethylaminomethyl)phenol, 4-cyanophenol, o-cresol, m-cresol, p-cresol, 4-ethylphenol, 4-isopropylphenol, 2,4-dimethylphenol, 3,5-dimethylphenol, nonylphenol, Eugenol, isoeugenol, cardanol and other alkylated phenols, 2,2'-dihydroxybiphenyl, 2,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, bisphenol A, bisphenol F, catechol, 4-tert-butylcatechol, resorcinol, 4-hexylresorcinol, orcinol, hydroquinone, naphthalene diol, anthracene diol, biphenol and other substituted diphenols, phloroglucinol, 2,4,6,3',5'-biphenylpentaphenol (phloroglucide), calixarene, poly (4-vinylphenol) and other polyphenols.

[0129] The one or more catalysts may be organic catalysts. "Organic catalyst" is understood to be a catalyst comprising at least carbon and hydrogen atoms and optionally other atoms selected from N, O, S, P and / or halogen. In one embodiment, the one or more catalysts claimed include organic catalysts. In a further embodiment, the one or more catalysts are organic catalysts.

[0130] In the context of the present invention, an "organic catalyst" provides a catalytic reaction that is not affected by metal atoms. Preferably, the organocatalyst does not contain any catalytically active metal atoms. That is, preferably the organocatalyst does not contain any catalytically active metal atoms, such as zinc, tin, magnesium, cobalt, calcium, titanium, aluminum, tannate, strontium, bismuth and / or zirconium atoms.

[0131] In one embodiment, the one or more catalysts include a tertiary amine, such as 2,4,6-tris(dimethylaminomethyl)phenol. In one embodiment, the one or more catalysts include a phenol derivative having electron withdrawing substituents, such as fluorophenol or nitrophenol.

[0132] The catalyst may be used alone or in combination of two or more catalysts. In one embodiment, the catalyst comprises a mixture of a tertiary amine and one or more phenol derivatives having electron withdrawing substituents (eg, fluorophenol or nitrophenol).

[0133] The amount and type of catalyst to be used must be adjusted according to the reactivity of the catalyst, the functional groups on the binder system and the required curing time and fire resistance. Preferably, the total concentration of the catalyst is 0.1-10.0%, such as 0.5-10%, such as 0.5-9%, such as 0.5-8% or 0.5-7% or 0.5-6% or 0.5-5% by weight of the coating composition; or 1-10%, such as 1-9% or 1-8% or 1-7% or 1-6% or 1-5%; or 2-10%, such as 2-9%, such as 2-8% or 2-7% or 2-6% or 2-5%.

[0134] In one embodiment, the catalyst has a Mw of less than 1000 g / mol, such as less than 750, such as less than 500, such as less than 400 or 300 or 200 g / mol.

[0135] In a preferred embodiment, the one or more catalysts do not include any polymer-based catalysts. In a preferred embodiment, the one or more catalysts do not include any aminosilanes.

[0136] In one embodiment, the claimed intumescent coating does not contain a metal catalyst. In one embodiment, the claimed catalyst or catalysts are not metal catalysts. "Metal catalyst" is understood to be a catalyst comprising metal atoms. Non-limiting examples of metal catalysts include catalysts comprising tin, titanium, zinc, aluminum, bismuth, zirconium, tin, cobalt, strontium, magnesium and calcium.

[0137] Expansion Pack

[0138] The claimed intumescent coating composition itself comprises an intumescent component. "Intumescent" means to carbonize and expand. In the context of the present invention, an "intumescent component" refers to a component selected from an acid generating compound, an intumescent agent and a carbon donor compound. In this context, an "intumescent package" refers to a group of compounds comprising one or more first compounds comprising an acid generating compound, optionally one or more second compounds comprising an intumescent agent, and optionally one or more further compounds comprising a carbon donor compound. The term "foaming agent" or "intumescent ingredient" may be used interchangeably with the term "intumescent component".

[0139] Acid-generating compounds

[0140] The expansion package c) comprises one or more first compounds that are acid generating compounds. The acid generating compound (sometimes referred to as a char former) generally comprises a source of a strong acid (e.g. phosphoric acid or sulfonic acid) that is capable of generating an acid, e.g. phosphoric acid or sulfonic acid, respectively, when exposed to heat (particularly at temperatures above 200° C.). Examples of the source include sodium phosphate, potassium phosphate (e.g. potassium tripolyphosphate), ammonium phosphate (e.g. ammonium polyphosphate (APP), monoammonium phosphate, diammonium phosphate), sodium sulfate, potassium sulfate, ammonium sulfate, magnesium sulfate or p-toluenesulfonic acid, or any combination thereof.

[0141] In one embodiment, the acid generating compound comprises a phosphate ester of a polyol, or ammonium phosphate (e.g., APP), or an amine phosphate (e.g., melamine phosphate), or a combination thereof. A particularly useful acid generating compound is APP, since it generates phosphoric acid at a temperature generally below the decomposition temperature of the carbon donor compound described below. Thus, in a preferred embodiment, the one or more acid generating compounds comprise ammonium polyphosphate (APP).

[0142] The phosphoric acid produced by APP can then participate in the carbonization reaction. APP compounds are polyphosphates with POP bonds, which can be represented by the following formula: [NH4P03] n , wherein the average value of n is at least about 10. Particularly useful APP compounds in the intumescent coating compositions of the present invention include compounds where n>1000.

[0143] In one embodiment, the acid-generating compound may include boric acid or a source of boric acid capable of generating boric acid upon exposure to heat, particularly at temperatures above 200° C. The source of boric acid may include, for example, borates such as ammonium pentaborate, zinc borate, sodium borate, lithium borate, aluminum borate, magnesium borate, borosilicate compounds, and any combination thereof.

[0144] The amount of the acid generating compound is generally 10-50 wt%, such as 15-40 wt%, preferably 15-30 wt% or 15-25 wt%, based on the total weight of the intumescent coating composition.

[0145] Bulking Agent

[0146] The expansion bag itself includes expandable expansive material. Typically, the expansive material includes one or more second compounds, which are referred to as "expansive agent" (sometimes also referred to as foaming agent) in the context of this article. The expansive agent will produce non-combustible gas when it encounters fire or is heated, generally nitrogen or ammonia. The gas produced can expand the charcoal, thereby forming a foamy protective layer, as further described below. Suitable examples of commercially available expansion agents include but are not limited to nitrogen-containing compounds, such as glycine, melamine, melamine salts, melamine derivatives, urea, urea derivatives, dicyandiamide, guanidine, boron-containing compounds and isocyanurate derivatives, and combinations thereof.

[0147] Melamine derivatives include, for example, melamine formaldehyde, methylolated melamine, hexamethoxymethyl melamine, melamine monophosphate, di-melamine phosphoric acid, melamine diphosphate, melamine polyphosphate, melamine pyrophosphate, melamine cyanurate, melamine borate, melam (N2-(4,6-diamino-1,3,5-triazine-2-yl)-1,3,5-triazine-2,4,6-triamine), melem (2,5,8-triamino-1,3,4,6,7,9,9b-heptaazaphenazone) and melon (poly [8-amino-1,3,4,6,7,9,9b-heptaazaphenazone-2,5-diyl) imino). In one embodiment, the expander includes melamine. In one embodiment, the expander does not contain melamine. If the intumescent agent comprises melamine, the amount of melamine is preferably less than 15 wt%, such as less than 10 wt%, based on the total weight of the intumescent composition. The intumescent agent may also include melamine derivatives, such as melamine phosphate or melamine polyphosphate.

[0148] Urea derivatives include, for example, N-alkylureas such as methylurea, N,N′-dialkylureas such as dimethylurea, and N,N,N′-trialkylureas such as trimethylurea, guanylurea, guanylurea phosphate, formamide semicarbazide, guanylurea phosphate, 1,3-diaminourea, bisurea and the like.

[0149] Isocyanurate derivatives of interest include tris-(2-hydroxyethyl)isocyanurate (THEIC). Boron-containing compounds useful as expanders in the present invention include, but are not limited to, boric acid and borates, such as ammonium pentaborate, zinc borate, sodium borate, lithium borate, aluminum borate, magnesium borate, and borosilicates.

[0150] The expansion agent may also include monomeric or polymeric compounds, such as meso-lactide, polylactide, polysulfone, polycarbonate, polyester, 1,1-bis-activated vinyl compound, or 1,1-bis-activated vinyl compound addition polymer, or any combination thereof. Physical expansion agents may also be used, such as expandable graphite and / or expandable microspheres containing gas.

[0151] Certain acid generating compounds such as ammonium (poly)phosphate and melamine (poly)phosphate are also capable of expansion and provide the same properties as added expansion agents (as described above). Thus, in one embodiment, the one or more first compounds that are acid generating compounds also function as expansion agents.

[0152] Therefore, in one embodiment, the c) expansion package does not contain any second compound that acts as an expansion agent. In a further embodiment, when the first compound containing an acid generating compound also acts as an expansion agent, there is no need to add a second compound containing an expansion agent. For example, in one embodiment, the one or more acid generating compounds include APP or melamine phosphate, and the second compound containing an expansion agent is not included. In this case, the one or more first compounds that act as both an acid generating compound and an expansion agent may be present in an amount of 10-50 wt%, such as 10-40 wt%, such as 10-30 wt%, based on the weight of the total coating composition.

[0153] In one embodiment, the expansion package contains one or more second compounds as expansion agents. When one or more second compounds as expansion agents are contained, the amount of the one or more second compounds is generally 0.5-15 wt %, preferably 1.0-10 wt %, more preferably 5.0-10 wt % of the total weight of the intumescent coating composition. In one embodiment, the c) expansion package contains one or more first compounds as acid generating compounds and one or more second compounds as expansion agents. In one embodiment, the one or more second compounds as expansion agents are contained, although the one or more first compounds may also function as expansion agents.

[0154] Carbon Donor Compounds

[0155] The intumescent coating composition must contain a carbon source. In one embodiment, the intumescent package also contains one or more additional compounds as carbon donor compounds. If present, the carbon donor compound may include an organic (poly) hydroxy compound (i.e., an organic (poly) alcohol) and / or expandable graphite. For example, the carbon donor compound may include pentaerythritol, dipentaerythritol, tripentaerythritol, a polysaccharide (e.g., starch, cellulose, glycogen, etc.), a disaccharide (e.g., sucrose, lactose, maltose, etc.), a monosaccharide (glucose, fructose, galactose, etc.), glycerol, expandable graphite, or any combination thereof. Other examples may be hydrocarbon resins, paraffin waxes, phosphate compounds, tall oil fatty acids (TOFA) or cardanol. Preferably, the carbon donor compound is selected from pentaerythritol and dipentaerythritol. Combinations of carbon donor compounds may be used.

[0156] In some cases, the binder system itself is capable of acting as a carbon source, and therefore the addition of a carbon donor compound in the expansion bag may be superfluous. In this case, coke may be formed simply by the reaction of the acid generating compound with the carbon donor present in the binder system.

[0157] Thus, in one embodiment, the c) expansion bag does not contain any other compound as carbon donor. In one embodiment, the binder system itself comprises a carbon donor. In a further embodiment, the binder system itself comprises a carbon donor, and the c) expansion bag does not contain any other compound as carbon donor.

[0158] When additional compounds (not part of the binder system) are included as one or more carbon donor compounds in the composition, the content of said compounds is typically up to 20 wt%, such as up to 15 wt%, such as up to 10 wt%, such as 3.0-20 wt%, such as 5.0-16 wt%, or 5.0-15 wt%, such as 1.0-12 wt%, or 5-10 wt%, based on the weight of the intumescent coating composition.

[0159] In one embodiment, the c) expansion package comprises one or more first compounds as acid generating compounds and one or more additional compounds as carbon donor compounds. In a further embodiment, the first compound as acid generating compound also acts as an expansion agent. In one embodiment, the c) expansion package comprises one or more first compounds as acid generating compounds, one or more second compounds as expansion agents, and one or more additional compounds as carbon donor compounds.

[0160] In one embodiment, the expansion package comprises less than 10 wt% expandable graphite.

[0161] Flame retardants

[0162] The expansion package may also contain at least one flame retardant, such as a phosphorus-containing flame retardant. Suitable flame retardants include phosphoric acid, phosphites, phosphonates and phosphates. Triaryl phosphates are preferred, especially triphenyl phosphate.

[0163] If present, the flame retardant may be present in an amount up to 15 wt%, preferably 2.5 to 15 wt%, such as 2.5 to 12.5 wt%, or 3.0 to 10 wt%, based on the total weight of the intumescent coating composition.

[0164] Reaction mechanism

[0165] When the intumescent coating is exposed to fire or heat, and the temperature of the coating is greater than 200°C, the acid generating compound decomposes to provide an acid. The carbon donor compound and / or the binder system may react with the acid to form a carbonaceous char. For example, ammonium polyphosphate decomposes at about 240°C to form ammonia and phosphoric acid. Phosphoric acid, as an acid, may be used in a dehydration reaction of an organic polyol compound as a carbon donor compound, such as starch, cellulose, non-polymeric sugars (e.g., glucose, fructose, sucrose, etc.), pentaerythritol, dipentaerythritol or tripentaerythritol, or any combination thereof.

[0166] Phosphoric acid reacts with hydroxyl groups to form thermally unstable phosphate esters, which decompose to release carbon dioxide and regenerate phosphoric acid. The dehydrated carbon donor and / or binder system forms carbonaceous coke, which is expanded into foam by the carbon dioxide. The expandable material also decomposes at high temperatures (e.g., above 200° C.) and produces additional gases, which expand the volume of the carbonaceous coke and produce carbonaceous foam.

[0167] In one embodiment, the intumescent component is present in an amount such that the intumescent coating is able to expand to at least twice, such as at least three times, such as at least 5 times or possibly even up to 10 times or more relative to its original volume when exposed to fire temperatures. The temperatures in a fire may be in the range of 150-1000°C or even higher, preferably the composition begins to expand at a lower temperature within this range. The expansion factor of a coating relative to its original film thickness is generally referred to as its expansion rate.

[0168] In the context of the present invention, the intumescent pack is typically present in an amount of 30-50% by weight of the coating composition, such as 30-45% or 35-50%, preferably 35-45%.

[0169] fiber

[0170] In order to increase the structural strength of the coke foam, fiber or glass reinforcements may optionally be added to the intumescent coating composition. Suitable inorganic and organic fibers and glass reinforcements are known in the art. As shown in the working examples, the intumescent coating composition of the present invention also functions well without the addition of fibers. If fibers are present in the coating composition, these fibers are typically added in an amount of up to 20%, such as up to 15%, such as up to 10%, such as up to 5%, by weight of the composition.

[0171] Other components

[0172] The claimed intumescent coating composition typically further comprises other components selected from fillers, pigments and additives which are not part of the intumescent package. Thus, in one embodiment, the intumescent coating composition further comprises d) one or more components selected from pigments, fillers, additives and solvents.

[0173] Pigments and fillers are considered herein as ingredients that may be added to a coating composition.

[0174] Examples of pigments are various grades of titanium dioxide, red iron oxide, zinc oxide, carbon black, graphite, yellow iron oxide, molybdate red, molybdate yellow, zinc sulfide, antimony oxide, sodium aluminum sulfosilicate, quinacridone, phthalocyanine blue, phthalocyanine green, black iron oxide, indanthrene blue, cobalt aluminum oxide, carbazole dioxazine, chromium oxide, isoindoline orange, diacetoacetyl o-cresol, benzimidazolone, quinazone yellow, isoindoline yellow, tetrachloroisoindolone, and quinophthalone yellow.

[0175] Examples of the filler are calcium carbonate such as calcite, dolomite, talc, mica, feldspar, barium sulfate, kaolin, nepheline, silica (including hydrophilic and hydrophobic silica), perlite, magnesium oxide, quartz powder and the like.

[0176] Any pigments and / or fillers may typically comprise 0-60%, such as 0-50%, preferably 5-45%, such as 5-40%, or 5-35%, or 5-25%, or 5-20%, or 10-20%, such as 10-15% or 15-20% by weight of the coating composition.

[0177] In one embodiment, the intumescent coating composition further comprises d) one or more pigments. In a preferred embodiment, the one or more pigments comprise titanium dioxide.

[0178] Examples of additives are:

[0179] (i) non-reactive fluids, such as non-reactive organopolysiloxanes, such as unsubstituted polydimethylsiloxane, methylphenylpolysiloxane, petroleum, and combinations thereof;

[0180] (ii) surfactants, for example derivatives of propylene oxide or ethylene oxide such as alkylphenol-ethylene oxide condensates (alkylphenol ethoxylates), ethoxylated monoethanolamides of unsaturated fatty acids such as ethoxylated monoethanolamide of linoleic acid, sodium lauryl sulfate, and soya lecithin;

[0181] (iii) wetting agents and dispersants, such as those described in M. Ash and I. Ash, "Handbook of Paint and Coating Raw Materials, Vol. 1", 1996, Gower Publ. Ltd., Great Britain, pages 821-823 and 849-851;

[0182] (iv) thickeners and anti-settling agents (e.g. thixotropic agents), for example colloidal silica, hydrated aluminum silicate (bentonite), aluminum tristearate, aluminum monostearate, xanthan gum, chrysotile, pyrogenic silica, hydrogenated castor oil, organically modified clays, polyamide waxes and polyethylene waxes;

[0183] (v) dyes, such as 1,4-bis(butylamino)anthraquinone and other anthraquinone derivatives, toluidine dyes, etc.;

[0184] (vi) antioxidants, such as bis(tert-butyl)hydroquinone, 2,6-bis(tert-butyl)phenol, resorcinol, 4-tert-butylcatechol, tris(2,4-di-tert-butylphenyl)phosphite, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate, and the like; and

[0185] (vii) Adhesion promoters, for example aminosilanes or epoxysilanes.

[0186] Any additives may generally account for 0-30% by weight of the coating composition, such as 0-15%. Preferably, the coating composition comprises one or more thickeners and / or anti-settling agents (such as thixotropic agents), preferably in an amount of 0.2-10% by weight of the coating composition, such as 0.5-5%, such as 0.6-4%.

[0187] Furthermore, the coating composition may be supplemented with one or more solvents. Examples of solvents are aliphatic, cycloaliphatic and aromatic hydrocarbons, such as white spirit, cyclohexane, toluene, xylene and naphtha solvents; esters, such as methoxypropyl acetate, n-butyl acetate and 2-ethoxyethyl acetate; and mixtures thereof. Alternatively, the solvent system may include water or be water-based (water content in the solvent system>50%). Preferably, the boiling point of the solvent is 110°C or higher. The intumescent coating composition of the present invention can be prepared in a solvent-free form and therefore has good environmental properties. If any solvent is contained in the composition, its content is preferably less than 20 wt %, such as less than 15 wt %, such as less than 10 wt %, preferably less than 5 wt %, such as less than 2.5 wt % of the coating composition. In one embodiment, the coating composition is substantially free of any solvent, which means that no solvent is explicitly added. If any, only a small amount of one or more solvents is present in the coating composition due to the use of components that can be commercially obtained optionally as solutions in organic solvents. The coating composition may have a volatile organic content (VOC) of less than 300 g / L, such as less than 250 g / L, less than 150 g / L, less than 100 g / L, or even less than 50 g / L.

[0188] Preparation of coating compositions

[0189] The coating composition can be prepared by any suitable technique commonly used in the field of paint production. Thus, the various ingredients can be mixed together using a blender, a high-speed disperser, a ball mill, a pearl mill, a grinder, a three-roll mill, or the like.

[0190] The coating composition is usually prepared by mixing two or more components. Possible examples include, for example, two premixes, one premix comprising one or more epoxy-functional polysiloxanes and another premix comprising one or more catalysts. Optionally combined with a third premix comprising one or more amino-functional polysiloxanes. These premixes all contain or may contain expansion components. Acid-generating compounds are included in the premix that does not comprise amino-functional polysiloxanes to avoid premature reaction with active hydrogen. The premix may also optionally include components selected from solvents, additives, fillers and pigments. The premix may also optionally include fiber or glass reinforcement to increase the strength of the coke foam.

[0191] Multi-part kit

[0192] The coating composition may be delivered as a two-component or three-component system, the components being combined and thoroughly mixed immediately before use. Thus, in one aspect, the present invention also relates to a multi-part kit suitable for formulating the claimed coating composition, comprising two or three containers containing the components for preparing the intumescent coating composition.

[0193] In one embodiment, the present invention relates to a multi-part kit suitable for formulating an intumescent coating composition comprising a polysiloxane-based binder system, wherein the kit comprises A1) a first container comprising one or more epoxy-functional polysiloxanes as described above, and B) a second container comprising one or more catalysts as described above. In one embodiment, the kit further comprises A2) a third container comprising one or more amino-functional polysiloxanes as described above. In one embodiment, the container A1) and / or the container A2) further comprises one or more catalysts as described above.

[0194] In one embodiment, the present invention relates to a multi-part kit suitable for formulating an intumescent coating composition comprising a polysiloxane-based binder system, wherein the kit comprises A1) a first container comprising one or more epoxy-functional polysiloxanes as described above, and A2) a second container comprising one or more amino-functional polysiloxanes as described above, wherein the kit further comprises a third container comprising one or more catalysts as described above and / or the container A1) further comprises one or more catalysts. The kit and / or the container A2) further comprises one or more catalysts as described above.

[0195] The swelling component may be included in any suitable container, preferably in one or both of the containers containing the epoxy-functional polysiloxane and / or the amino-functional polysiloxane. Thus, in embodiments relating to variants of the above-described kit of parts, the container A1) and / or the container A2) further comprises one or more swelling components as described above. In a preferred embodiment, the acid-generating component is contained in the container A1) containing one or more epoxy-functional polysiloxanes.

[0196] In one embodiment relating to a variant of the above-described multi-part kit, said container A1) and said container A2) each comprise one or more epoxy-functional polysiloxanes and one or more amino-functional polysiloxanes in amounts such that when the contents of the containers are mixed in the correct proportions, the stoichiometric amount of active hydrogens on the amino-functional polysiloxane relative to epoxy groups on the epoxy-functional polysiloxane is at least 5%, such as at least 10%, preferably at least 15%, such as at least 20%, such as at least 25%, such as at least 30, 40, 50, 60, 70, 80, 90 or 100%.

[0197] It should be understood that when referring to a "coating composition", it refers to the mixed composition containing all ingredients ready to be applied to a substrate. In addition, all amounts expressed as weight percent (wt%) of the coating composition should be understood to be the wt% of the mixed coating composition ready to be applied, i.e. including the weight of solvent (if any).

[0198] Application of intumescent coating compositions

[0199] The coating compositions of the present invention are typically applied to at least a portion of a substrate surface.

[0200] The term "application / applying / applying" is used in its normal meaning in the paint industry. Thus, "application" can be carried out by any conventional means, such as by brush, roller, spraying, dipping, etc. The most commercially advantageous way of "applying" the coating composition is spraying. Thus, it is preferred that the coating composition is sprayable. Spraying is carried out by conventional spraying equipment known to those skilled in the art.

[0201] The intumescent coating composition is applied to provide a high dry film thickness, thereby ensuring a good fire protection effect. The film thickness applied may vary depending on the nature of the coated substrate and its predicted fire exposure scenario. The dry film thickness of the coating obtained from the intumescent coating composition is preferably in the range of 0.1-40 mm, such as 0.5-40 mm, such as 0.5-30 mm, such as 0.5-25 mm or 0.1-30 mm, such as 0.1-25 mm. Multiple layers of the intumescent coating composition may be applied to achieve a suitable dry film thickness.

[0202] In one aspect, the present invention relates to the use of the claimed intumescent coating composition for application to the surface of a substrate, such as a metal or metal alloy substrate, for example a steel substrate. The intumescent coating composition of the present invention is typically used for fireproofing buildings. The composition can be applied to the frame of the building, which is typically made of steel, either at a metal forming plant, an application shop ("off-site") or on site after the frame has been erected.

[0203] In some cases, it may be necessary to embed a high temperature resistant mesh in the layer of intumescent coating, as described in WO2016 / 0949763. Examples of such mesh materials include wire mesh, glass fiber mesh, carbon fiber mesh, and refractory mineral fiber mesh (e.g., basalt).

[0204] The surface to which the intumescent coating is applied may be a "virgin" surface (e.g. a steel surface). However, in some cases the substrate to be coated may have an existing coating, such as a primer layer and / or a tie layer, so that the surface to be coated with the intumescent coating composition consists of such a coating. Examples of suitable primer layers include coatings based on epoxy resins, polyurethanes, acrylics, vinyls and chlorinated rubbers. An epoxy primer layer is preferred. Alternatively, the substrate may have an old coating already applied to the surface, such as a worn-out fire-retardant intumescent coating or similar coating.

[0205] A decorative or protective topcoat may be applied over the cured intumescent coating of the invention, for example to provide color to exposed steel structures or to protect them from harsh environmental conditions.

[0206] The term "substrate" refers to a solid material on which the coating composition is applied. The substrate generally comprises a metal or a metal alloy, such as steel or iron. Other substrates may also be involved, such as concrete, wood or aluminum.

[0207] In one aspect, the present invention relates to a substrate having, on at least part of its surface, a coating obtained from the claimed intumescent coating composition. In a preferred embodiment, the substrate constitutes at least part of a building frame.

[0208] In one embodiment, the substrate has a multilayer system on at least a portion of the surface, the multilayer system comprising:

[0209] i) one or more cured primer layers and / or tie layers; and

[0210] ii) One or more coatings obtained from the coating composition of the invention.

[0211] In a further embodiment, the multi-layer system further comprises iii) one or more topcoats, such as decorative or protective topcoats.

[0212] In one embodiment, the primer layer is an anti-corrosion primer layer.

[0213] The term "surface" is used in its normal sense to refer to the outer boundary of an object. A specific example of such a surface is the surface of a metal structure or a metal alloy structure (eg a steel structure).

[0214] All references (including publications, patent applications, and patents) cited herein are hereby incorporated by reference in their entirety to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein (to the maximum extent permitted by law), regardless of whether an incorporation of a specific document is separately provided elsewhere herein.

[0215] The terms "a", "an", "the", and similar references used in the context of describing the present invention should be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. For example, the phrase "the composition" should be understood to refer to various "compositions" of the present invention or particular described aspects, unless otherwise indicated.

[0216] The use of terms such as "comprising," "having," "including," or "containing" in the description of any aspect or aspect of the invention herein to refer to one or more elements is intended to provide support for similar aspects or aspects of the invention "consisting of," "consisting essentially of," or "essentially comprising," unless otherwise specified or clearly contradicted by context (for example, a composition described herein as comprising a particular element should be understood to also describe a composition consisting of the element, unless otherwise specified or clearly contradicted by context).

[0217] The use of any and all examples or exemplary language (including "for example," "for example," "such as," and "eg") in this specification is intended merely to better illuminate the present invention and does not pose a limitation on the scope of the present invention unless otherwise specified.

[0218] The titles and subtitles used herein are for convenience only and should not be construed as limiting the present invention in any way. Any and all examples or exemplary language (including "such as", "for example", "such as" and "such as") used in this specification are intended only to better illustrate the present invention and, unless otherwise indicated, do not limit the scope of the present invention. The citation and inclusion of patent documents herein are merely for convenience and do not reflect any view on the validity, patentability and / or enforceability of such patent documents.

[0219] It should be understood that the various aspects, embodiments, implementations and features of the present invention mentioned herein may be claimed individually or in any combination. Example

[0220] The invention will now be illustrated by the following non-limiting examples.

[0221] For simplicity, the terms "epoxy-functional polysiloxane" and "amino-functional polysiloxane" are simplified to "epoxy polysiloxane" and "amine polysiloxane" in the examples.

[0222] Fire test

[0223] Fire tests were carried out in a gas oven according to the ISO834 fire curve. All coating compositions were applied manually with a spatula or by pouring the paint until a film thickness of 5000 μm was reached. A 200×300×5 mm steel plate coated with a primer layer (Hempel 15280 primer, 20 μm DFT) was used, and a mold was used around the liquid to confine it until it became solid. The steel plate was cured at 23°C and the paint was demoulded once it became hard enough to withstand processing (usually 12-24 hours). After that, they were cured at a temperature of 23°C until the total curing time was seven days, after which they were tested. All reported failure times (TTF) have been corrected using the following formula to compensate for small DFT deviations:

[0224]

[0225] Hardness development

[0226] The samples were applied to a flat plastic surface at a thickness of 3-5 mm and cured at a temperature of 23° C. Shore A and Shore D hardness measurements were performed using a durometer 24 hours, 48 ​​hours and 7 days after application. The reported results represent the average hardness value obtained after three measurements (the higher the value, the greater the hardness).

[0227] Raw materials list

[0228] Epoxy polysiloxane I: GP-554, available from Genesee Polymers

[0229] Epoxy polysiloxane II: GP-607, available from Genesee Polymers

[0230] Amine polysiloxane I: Dowsil 3055, available from Dow

[0231] Amine polysiloxane II: Wacker Fluid NH 02 D, available from Wacker

[0232] Amine polysiloxane III: Silamine A0-EDA, obtained from Siltech

[0233] Organic (epoxy) resin: Epikote 828 from Hexion (bisphenol A diglycidyl ether)

[0234] Epoxy curing agent: Ancamide 903 MAV from Evonik (aliphatic polyamidoamine)

[0235] Acid generating compound: Exolit AP 422 from Clariant (ammonium polyphosphate)

[0236] Catalyst I: Ancamine K 54 from Evonik (2,4,6-tris(dimethylaminomethyl)phenol)

[0237] Catalyst II: 2-fluorophenol, obtained from Sigma-Aldrich and TCI chemicals

[0238] Catalyst III: 2-nitrophenol, obtained from Sigma-Aldrich and TCI chemicals

[0239] Expanding agent: Melafine, obtained from OCI nitrogen (melamine)

[0240] Carbon donor compound: Charmor PM 40 from Perstorp (pentaerythritol)

[0241] Pigment: Tioxide TR 81 from Venator (titanium dioxide)

[0242] Preparation of Exemplary Coating Compositions

[0243] All coating compositions were formulated to have 40% by volume content of intumescent components and pigments (acid generating compound + intumescent agent + carbon donor compound + pigment), and the stoichiometry and polysiloxane content as shown in the table below. The weight ratio of acid generating compound, intumescent agent, carbon donor compound and pigment was kept constant at 3:1:2:2. The catalyst content was 9:1 binder / catalyst weight ratio.

[0244] Each formulation is divided into two different parts or containers. Part A contains the epoxy functional resin and any Lewis acid or Bronsted acid catalyst present in the composition. Part B contains the amino functional resin and / or any nucleophilic catalyst used. APP is always dispersed in Part A to avoid premature reaction with the nucleophile in Part B. All other components are distributed in Part A and Part B in amounts that allow preparation. Dispersion is always carried out using a standard high speed disperser (USD). Part A and Part B are mixed using a stirrer immediately before use.

[0245] The amount of each component shown in the following table is given as a percentage of the total weight of each coating composition.

[0246] "Stoichiometric" refers to the percent chemical amount between the active hydrogens of the amino and epoxy groups.

[0247] Table 1a: Epoxy polysiloxane II and stoichiometrically increased amine polysiloxane I, catalyst I

[0248]

[0249] Table 1b: Epoxy polysiloxane I and stoichiometrically increased amine polysiloxane I, catalyst I

[0250]

[0251] Table 1c: Epoxy polysiloxane I and different stoichiometric amine polysiloxanes II and III, catalyst I

[0252]

[0253] Tables 1a, 1b and 1c show that catalyst I (2,4,6-tris(dimethylaminomethyl)phenol) provides intumescent coatings with good fire protection properties, regardless of the choice of polysiloxane. The fire protection properties are shown by failure times in the range of 75-125 minutes. When the epoxy polysiloxane is crosslinked with the amine polysiloxane, the hardness development is improved. In particular, the fire protection properties are very good when the stoichiometry is at least 10%.

[0254] Table 2a: Epoxy polysiloxane II, amine polysiloxane I, catalysts I and II

[0255]

[0256] As shown in Table 2a, the combination of Catalysts I and II provides an intumescent coating with excellent fire resistance with a time to failure in the range of 130-150 minutes. When the epoxy polysiloxane is crosslinked with the amine polysiloxane, hardness development is improved.

[0257] Table 3a: Epoxy polysiloxane I, amine polysiloxane I with different stoichiometric amounts, catalysts I and III

[0258]

[0259] Table 3b: Epoxy polysiloxane II, amine polysiloxane I with different stoichiometry, catalysts I and III

[0260]

[0261] Tables 3a and 3b show that the combination of Catalysts I and III provided intumescent coatings with a time to failure of 85-110 minutes. As the amine polysiloxane content increased, the hardness development improved.

[0262] Table 4: Epoxy homopolymers with increasing amounts of organic resin

[0263]

[0264] Table 4 shows that increasing the organic resin content in the binder system has a negative impact on the fire performance.

[0265] Table 5: Comparative formulations without catalyst

[0266]

[0267] Table 5 shows that the compositions prepared without a catalyst had a failure time of 40-65 minutes, which is much lower than the failure time obtained for the claimed intumescent coating compositions.

[0268] Table 6: Comparative Formulations Containing Only Organic Resins

[0269]

[0270] Table 6 shows that the failure times for the compositions based on purely organic (epoxy) binder systems are between 40 and 65 minutes, which is much lower than the failure times obtained for the claimed intumescent coating compositions.

Claims

1. An intumescent coating composition comprising: a) a polysiloxane-based binder system comprising i) one or more epoxy-functional polysiloxanes; and b) one or more catalysts.

2. The intumescent coating composition according to claim 1, wherein the a) polysiloxane-based binder system further comprises ii) one or more amino-functional polysiloxanes.

3. An intumescent coating composition according to any one of claims 1 to 2, wherein the epoxy-functional polysiloxane has at least two epoxy functional groups.

4. The intumescent coating composition according to any one of claims 1 to 3, further comprising c) an intumescent package.

5. An intumescent coating composition according to any one of claims 1 to 4, wherein the binder system comprises more than 50 wt% polysiloxane, such as more than 55 wt%, more than 60 wt% or 65 wt%, preferably more than 70 wt%, such as more than 75 wt% or 80 wt% or 85 wt% or 90 wt% or 95 wt% polysiloxane, for example about 100 wt% polysiloxane, based on the total weight of the binder system.

6. An intumescent coating composition according to any one of claims 2 to 5, wherein the stoichiometry of active hydrogens on the amino functional polysiloxane relative to epoxy groups on the epoxy functional polysiloxane is at least 5%, such as at least 10%, preferably at least 15%, such as at least 20%, such as at least 25%, such as at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, such as about 100%.

7. An intumescent coating composition according to any one of claims 1 to 6, wherein the one or more epoxy-functional polysiloxanes are represented by the following formula (I) having a molecular weight of 200-500,000 g / mol: in: n+m+p is an integer between 2 and 7500, Each R1 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C 30 Alkenyl, C3-C 30 Cycloalkyl and aryl groups, Each R2 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C 30 Alkenyl, C3-C 30 Cycloalkyl and aryl groups, which are substituted with at least one epoxy functional group, and Each R3 is independently selected from Si(R1)3, Si(R1)2R2, Si(R1)(R2)2 and Si(R2)3; Provided that the epoxy-functional polysiloxane has at least one epoxy functional group.

8. The intumescent coating composition according to claim 7, wherein the epoxy functional group is selected from the following formula:

9. An intumescent coating composition according to any one of claims 2 to 8, wherein the one or more amino-functional polysiloxanes are represented by the following formula (II) having a molecular weight of 200-500,000 g / mol: in: q+r+s is an integer between 2 and 7500, Each R4 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C 30 Alkenyl, C3-C 30 Cycloalkyl and aryl groups, Each R5 is independently selected from a linear or branched C1-C 30 Alkyl, linear or branched C2-C 30 Alkenyl, C3-C 30 Cycloalkyl and aryl groups, which are substituted with at least one amino functional group, and Each R6 is independently selected from Si(R4)3, Si(R4)2R5, SiR4(R5)2 and Si(R5)3; Provided that the amino-functional polysiloxane has at least one primary amino-functional group, or at least two secondary amino-functional groups, or at least one primary amino-functional group and at least one secondary amino-functional group.

10. An intumescent coating composition according to any one of claims 1 to 9, wherein if any organic resin is present in the binder system, the organic resin is present in an amount of less than 50%, such as less than 40%, such as less than 30%, preferably less than 20%, such as less than 15% or 10% or 5% by weight of the binder system.

11. An intumescent coating composition according to any one of claims 1 to 10, wherein the one or more catalysts b) comprise an organic catalyst.

12. An intumescent coating composition according to any one of claims 1 to 11, wherein the one or more catalysts b) comprises a catalyst selected from a tertiary amine, such as 2,4,6-tris(dimethylaminomethyl)phenol, or a phenol derivative, such as fluorophenol or nitrophenol, or a combination thereof.

13. An intumescent coating composition according to any one of claims 1 to 12, wherein the one or more catalysts b) are present in a total amount of 0.1-10.0%, such as 0.5-10%, such as 0.5-9%, such as 0.5-8% or 0.5-7% or 0.5-6% or 0.5-5%; or 1-10%, such as 1-9%, such as 1-8% or 1-7% or 1-6% or 1.5-5% by weight of the coating composition.

14. An intumescent coating composition according to any one of claims 4 to 13, wherein the c) intumescent package comprises one or more first compounds which are acid generating compounds.

15. An intumescent coating composition according to any one of claims 4 to 14, wherein the c) intumescent package comprises one or more second compounds as intumescent agents.

16. An intumescent coating composition according to any one of claims 4 to 15, wherein the c) intumescent package further comprises one or more additional compounds which are carbon donor compounds.

17. A multi-part kit suitable for formulating an intumescent coating composition comprising a polysiloxane-based binder system, wherein the kit comprises: A1) a container containing one or more epoxy-functional polysiloxanes according to any one of claims 1 to 16, and B) A container containing one or more catalysts according to any one of claims 1 to 16.

18. A multi-part kit suitable for formulating an intumescent coating composition comprising a polysiloxane-based binder system, wherein the kit comprises: A1) a container containing one or more epoxy-functional polysiloxanes as claimed in any one of claims 1 to 16, and A2) a container containing one or more amino-functional polysiloxanes as described in any one of claims 2 to 16; and in: The container A1) further comprises one or more catalysts as described in any one of claims 1 to 16, and / or The container A2) further comprises one or more catalysts as described in any one of claims 1 to 16, The kit further comprises B) a container comprising one or more catalysts as described in any one of claims 1-16.

19. Use of the coating composition of any one of claims 1 to 16 for application on a substrate surface, wherein the substrate is, for example, a metal substrate or a metal alloy substrate, such as a steel substrate.

20. A substrate, such as a steel substrate, having on at least a portion of its surface a coating obtained from a coating composition according to any one of claims 1 to 16.

Images