Two-component system for protecting a pipe or tank component

Abstract

The present invention relates to a kit comprising a first component of a polyisocyanate and a second component of a mixture of polyaspartic esters. It also relates to a coated pipe or tank element comprising a coating formed from such a kit, as well as a pipe or tank comprising one or more of these coated pipe or tank elements. Furthermore, it relates to a method for protecting a raw cast iron, steel, or concrete pipe or tank element using such a kit.

Description

Title of the invention: Two-component system for protecting a pipe or tank element

[0001] The present invention relates to a kit comprising a first component comprising a polyisocyanate and a second component comprising a mixture of polyaspartic esters. It also relates to a coated pipe or tank element comprising a coating formed from such a kit, as well as a pipe or tank comprising one or more of these coated pipe or tank elements. Furthermore, it relates to a method for protecting a raw cast iron, steel, or concrete pipe or tank element using such a kit.

[0002] Cast iron pipes intended for systems for the transport or storage of drinking water or wastewater are generally protected by anti-corrosion coatings applied at the factory, both internally and externally, to extend their lifespan. However, during on-site installation, it is often necessary to cut the pipes to adjust their length, which exposes the raw cast iron to environmental and chemical attack. This temporary exposure, although localized, can create weak points where corrosion can develop.

[0003] More specifically, in the case of wastewater networks, the effluents flowing through the pipes undergo septic fermentation, leading to the formation of compounds such as hydrogen sulfide, which can transform into sulfuric acid in the presence of moisture. This acid is particularly corrosive, even to protected materials. Thus, a specific protective coating must be applied to the cut areas to provide the pipes with an effective chemical barrier.

[0004] Epoxy-based coating solutions are commonly used to meet these requirements. Epoxy coatings are widely recognized for their excellent chemical resistance, adhesion to various substrates, and durability in corrosive environments. Such coatings are described, in particular, in US 5,017,258 and US 7,387,138. However, such systems require extended curing (or drying) times, which can slow down work and complicate on-site implementation. Furthermore, these coatings, when applied to an external surface (typically a pipe), impose significant stress on the joint.

[0005] Thus, there remains a real need to provide a protective coating with a curing time adapted to the application conditions, while maintaining good corrosion resistance. It would also be advantageous if this coating were protection allows less effort to fit together, when applied to an external surface, particularly at one end of a pipe intended to be fitted into an adjacent pipe. Summary of the invention

[0006] In this context, the inventors demonstrated that the use of a two-component system comprising, on the one hand, a polyisocyanate and, on the other hand, a mixture of specific polyaspartic esters made it possible to address the aforementioned problems. More specifically, it was found that the combination of a linear polyaspartic ester with a cyclic polyaspartic ester resulted in a significantly shorter curing time than that obtained with epoxies, while remaining long enough to allow for proper application to the pipe. Excellent chemical resistance to acidic pH was also observed. Furthermore, it was demonstrated that this type of coating, when applied to the exterior surface of a pipe, resulted in less stress during assembly.

[0007] Thus, the present invention relates to a kit comprising:

[0008] - a first component comprising a polyisocyanate; and

[0009] - a second component comprising a polyaspartic ester of formula (I) and a polyaspartic ester of formula (II):

[0010] [Chem.l]

[0011] where:

[0012] - in formula (I), each R is a C1-C6 alkyl group and X is a divalent group acyclic aliphatic in C3-C12;

[0013] - in formula (II), each R' is a C1-C6 alkyl group and X' is a divalent group cyclic in C6-C18 or a divalent aliphatic group in C6-C18 comprising at least one cyclic group in C3-C12.

[0014] In some embodiments, the polyisocyanate is a triisocyanate, such as the isocyanurate trimer of 1,6-hexamethylene-diisocyanate.

[0015] In certain embodiments, in formula (I):

[0016] - each R is a C1-C3 alkyl, preferably an ethyl, and

[0017] - X is a C4-C8 alkylene, preferably branched.

[0018] In certain embodiments, in formula (II):

[0019] - each R' is a C1-C3 alkyl, preferably an ethyl, and

[0020] - X' is a C6-C16 aliphatic divalent group comprising at least one group C5-C12 cycloalkylene.

[0021] In certain embodiments, the polyaspartic ester of formula (I) is represented as follows:

[0022] [Chem.2]

[0023] and the polyaspartic ester of formula (II) is represented as follows:

[0024] [Chem.3]

[0025] In some embodiments, the mass ratio of the polyaspartic ester of formula (I) to the polyaspartic ester of formula (II) is 0.05 to 1, preferably 0.1 to 0.8, or even 0.2 to 0.5, or even 0.3 to 0.4.

[0026] In some embodiments, the mass ratio of the sum of polyaspartic esters of formula (I) and formula (II) to polyisocyanate is 0.4 to 1.5, preferably 0.5 to 1.3, or even 0.6 to 1.2 or even 0.6 to 1.1.

[0027] In some embodiments, the second component does not include aromatic amine or if it does, then the aromatic amine content is less than 2% by weight, or even less than 1% by weight, relative to the total weight of the second component.

[0028] The present invention also relates to a coated pipe or tank element comprising:

[0029] - a raw cast iron, steel or concrete pipe or tank element,

[0030] - a coating located on at least part of an exterior wall and / or on the less a portion of an inner wall of the raw piping or tank element,

[0031] said protective coating being formed from a kit as defined in this application.

[0032] Another object of the present invention is a pipeline or tank comprising one or more coated pipeline or tank elements as defined in this application, the pipeline or tank preferably being intended for the supply, distribution or storage of drinking water or wastewater.

[0033] Another object of the present invention is a method for protecting a raw cast iron, steel or concrete pipe or tank element comprising:

[0034] a) bringing said first component and said second component of a kit as defined in this application into contact, thus forming a mixture;

[0035] b) the application of said mixture to at least part of an outer wall and / or at least part of an inner wall of the raw cast iron, steel or concrete pipe or tank element, thus forming an intermediate coating; and

[0036] c) the hardening of said intermediate coating, thus forming the protective coating.

[0037] In certain embodiments, said mixture is applied in step b) to at least part of an outer wall of the raw cast iron, steel or concrete pipe or tank element and optionally to at least part of an inner wall of the raw cast iron, steel or concrete pipe or tank element. DETAILED DESCRIPTION

[0038] The kit according to the invention comprises a first component and a second component. The first component and the second component are typically in separate compartments of the kit.

[0039] The first component comprises a polyisocyanate. By "polyisocyanate" is meant a compound comprising at least two isocyanate (-NCO) functional groups. Preferably, the polyisocyanate is a diisocyanate, a triisocyanate, a tetraisocyanate, or a mixture of at least two of these. Even better, the polyisocyanate is a triisocyanate.

[0040] Examples of diisocyanates include: 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene bis-(4-cyclohexylisocyanate) (HMDI), pentamethylene diisocyanate (PDI), 4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, dicyclohexylmethane diisocyanate, tetramethylxylene diisocyanate, norbomane diisocyanate, bis-(isocyanatomethyl)cyclohexane, tetramethylene-1,4-diisocyanate, cyclohexane-1,4-diisocyanate, 1,12-dodecane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, diphenylmethylene 2,2'-diisocyanate (2,2'-MDI), the 4,4'-diphenylmethylene diisocyanate (4,4'-MDI), 4,4'-Dibenzyl diisocyanate (4,4'-DBDI), 2,6-Toluene diisocyanate (2,6-TDI), m-Xylylene diisocyanate (m-XDI), 2,4'-Diphenylmethylene diisocyanate (2,4'-MDI), 2,4'-Dibenzyl diisocyanate (2,4'-DBDI), 2,4-Toluene diisocyanate (2,4-TDI), or a mixture of at least two of these.

[0041] Examples of triisocyanate include: triphenylmethane triisocyanate, 2,4,6-toluene triisocyanate, 1,3,5-tris(6-isocyanatohexyl)biuret, trimethylmethane triisocyanate, lysine triisocyanate, 1,3,6-triisocyanatohexane, a diisocyanurate isocyanurate trimer (where the diisocyanate is typically selected from the diisocyanates mentioned above), or a mixture of at least two of these.

[0042] Preferably, the polyisocyanate is an isocyanurate trimer of diisocyanate, where the diisocyanate is typically chosen from the diisocyanates mentioned above, preferably where the diisocyanate is 1,6-hexamethylene-diisocyanate.

[0043] The 1,6-hexamethylene-diisocyanurate isocyanurate trimer can be represented by the following formula:

[0044] [Chem.4]

[0045] Preferably, the polyisocyanate does not comprise urethdione groups or allophanate groups.

[0046] Preferably, the polyisocyanate is not a prepolymer. Prepolymeric polyisocyanates are well known to those skilled in the art, and are compounds formed by reaction between a polyisocyanate and a compound having at least two reactive functions with respect to isocyanates (e.g., polyols, polyamines).

[0047] The molar mass of polyisocyanate is advantageously from 100 to 800 g / mol, or even from 150 to 700 g / mol, or even from 180 to 600 g / mol.

[0048] Advantageously, in the first component, the weight content of polyisocyanate is 50 to 100%, preferably 75 to 100%, or even 90 to 100%, or even 98 to 100%, relative to the total weight of the first component.

[0049] Advantageously, the first component of the kit according to the invention is essentially devoid of (or even does not include) ingredients reactive to isocyanate functions, in particular ingredients comprising -NH-, -NH2, -OH, or -SH groups, such as an aspartic or polyaspartic ester (e.g., polyaspartic ester). of formula (I) or (II) as defined in this application). In particular, it is preferable that the first component of the kit according to the invention not include any aromatic amine (i.e., mono- or polyamine) or if it does, then the aromatic amine content is less than 2% by weight, or even less than 1% by weight, relative to the total weight of the first component.

[0050] Advantageously, the first component does not comprise polyisocyanate including urethdione groups, or if it does, then the content of polyisocyanate including urethdione groups is less than 2% by weight, or even less than 1% by weight, relative to the total weight of the first component.

[0051] Advantageously, the first component does not comprise polyisocyanate comprising allophanate groups, or if it does, then the content of polyisocyanate comprising allophanate groups is less than 2% by weight, or even less than 1% by weight, relative to the total weight of the first component.

[0052] Advantageously, the first component does not comprise prepolymeric polyisocyanate, or if it does, then the prepolymeric polyisocyanate content is less than 2% by weight, or even less than 1% by weight, relative to the total weight of the first component.

[0053] The second component of the kit according to the invention comprises a polyaspartic ester of formula (I) and a polyaspartic ester of formula (II):

[0054] [Chem.5] ° û (0 0 0 (III

[0055] where:

[0056] - in formula (I), each R is a C1-C6 alkyl group and X is a divalent group acyclic aliphatic in C3-C12;

[0057] - in formula (II), each R' is a C1-C6 alkyl group and X' is a divalent group cyclic in C6-C18 or a divalent aliphatic group in C6-C18 comprising at least one cyclic group in C3-C12.

[0058] In the expression, "a C6-C18 aliphatic divalent group comprising at least one C3-C12 cyclic group" relating to X', it is understood that the number of C6-C18 carbons is the total number of carbons in group X' and therefore includes the carbon atoms of said at least one C3-C12 cyclic group.

[0059] By "aliphatic" is meant a non-aromatic hydrocarbon group, cyclic or acyclic, saturated or unsaturated, linear or branched.

[0060] By "alkyl" is meant a non-cyclic, linear or branched, saturated hydrocarbon group.

[0061] By "alkylene" is meant a non-cyclic, linear or branched, saturated divalent hydrocarbon group.

[0062] By "cycloalkylene" is meant a non-aromatic, mono- or poly-cyclic, saturated, divalent hydrocarbon group.

[0063] By "arylene" is meant an aromatic hydrocarbon divalent group.

[0064] In formula (I), it is advantageous for each R to be a C1-C3 alkyl, for example a methyl, ethyl, propyl or isopropyl. Preferably, each R is an ethyl.

[0065] In formula (I), it is advantageous for X to be a C4-C8 alkylene (e.g., C5-C7). Preferably, X is a branched C4-C8 alkylene (e.g., C5-C7).

[0066] In a particularly preferred embodiment, the polyaspartic ester of formula (I) is represented as follows:

[0067] [Chem.6]

[0068] In formula (II), it is advantageous for each R' to be a C1-C3 alkyl, for example a methyl, ethyl, propyl, or isopropyl. Preferably, each R' is an ethyl.

[0069] In formula (II), X' can in particular be:

[0070] - a C6-C12 cycloalkylene group,

[0071] - an arylene group at C6-C12 (e.g., a phenylene or a bis-phenylene), or

[0072] - a C6-C16 aliphatic divalent group comprising at least one group C5-C12 cycloalkylene.

[0073] Examples of C6-C12 cycloalkylene groups include: cyclohexylene (C6), cycloheptylene (C7), cyclooctylene (C8), cyclononylene (C9), cyclodecylene (C10), cycloundecylene (C11), cyclododecylene (C12)).

[0074] Advantageously, X' is a C6-C16 aliphatic divalent group comprising at least one C5-C12 cycloalkylene group (e.g., cyclopentylene (C5), cyclohexylene (C6), cycloheptylene (C7), cyclooctylene (C8), cyclononylene (C9), cyclodecylene (C10), cycloundecylene (C11), cyclododecylene (C12)).

[0075] Preferably, X' is a C10-C16 aliphatic divalent group comprising at least one C5-C8 cycloalkylene group.

[0076] Better still, X' is a C10-C16 aliphatic divalent group comprising two C5-C8 cycloalkylene groups, the two C5-C8 cycloalkylene groups advantageously being cyclohexylenes.

[0077] In a particularly preferred embodiment, the polyaspartic ester of formula (II) is represented as follows:

[0078] [Chem.7]

[0079] Advantageously, the second component of the kit according to the invention is essentially devoid of (or even does not include) compounds comprising one or more isocyanate functions, such as a polyisocyanate.

[0080] Preferably, the second component of the kit according to the invention is essentially devoid of (or even does not include) any polyaspartic ester other than the polyaspartic ester of formula (I) and the polyaspartic ester of formula (II). For example, in the second component, the weight content of polyaspartic ester other than the polyaspartic ester of formula (I) and the polyaspartic ester of formula (II) is preferably less than 5% (or even less than 2%, or even less than 1%) by weight of the total weight of the second component.

[0081] Preferably, the second component of the kit according to the invention does not include an aromatic amine (i.e. mono- or polyamine) (in particular, distinct from the polyaspartic ester of formula (II)) or if it does include one, then the aromatic amine content (in particular, distinct from the polyaspartic ester of formula (II)) is less than 2% by weight, or even less than 1% by weight, relative to the total weight of the second component.

[0082] It is preferable that the second component of the kit according to the invention not include water, or if it does include water, then the water content by weight is preferably less than 1% (or even less than 0.5%, or even less than 0.1%) relative to the total weight of the second component.

[0083] Advantageously, in the second component, the total weight content of polyaspartic ester of formula (I) and formula (II) is from 15 to 100%, preferably of 20 to 80%, or even 25 to 60%, or even 50 to 60%, relative to the total weight of the second component.

[0084] In a particular embodiment, in the second component, the total weight content of polyaspartic ester of formula (I) and of formula (II) is 20 to 60%, for example 20 to 50%, relative to the total weight of the second component.

[0085] Advantageously, in the second component, the mass ratio of the polyaspartic ester of formula (I) to the polyaspartic ester of formula (II) is 0.05 to 1, preferably 0.1 to 0.8, or even 0.2 to 0.5, or even 0.3 to 0.4.

[0086] Advantageously, in the kit according to the invention, the mass ratio of the sum of the polyaspartic esters of formula (I) and of formula (II) to the polyisocyanate is 0.4 to 1.7, preferably 0.4 to 1.5, better still 0.5 to 1.3, or even 0.6 to 1.2 or even 0.6 to 1.1 (for example 0.65 to 1.0).

[0087] Each of the first component and the second component of the kit according to the invention may include other ingredients, typically to adjust their physico-chemical properties or those of the coating intended to be formed.

[0088] In particular, each of the first and second components of the kit according to the invention may comprise one or more mineral fillers and / or one or more additives. These additives may, in particular, be selected from dispersing agents, sliding agents, rheological agents, defoaming agents, pigments, or a mixture of at least two of these.

[0089] The mineral fillers are preferably selected from calcium carbonate, calcium stearate, clays, talc, dolomite, mica, silica sands, crushed basalt, barium sulfate, kaolin, and a mixture of at least two of these. The mineral fillers generally have a d50 (in number) ranging from 0.5 to 500 pm, in particular from 1 to 200 pm, measured by laser granulometry.

[0090] The pigments can, for example, be chosen from inorganic pigments (for example, titanium dioxide or an iron oxide), organic pigments (for example, carbon black) and a mixture of these.

[0091] Dispersing agents may, for example, be a dispersing agent based on silicone, polyacrylate or polyether.

[0092] The defoaming agents may, for example, be chosen from silicone defoaming agents, fluoro-silicone defoaming agents, mineral oils, acrylic polymers, vinyl polymers and a mixture of at least two of these.

[0093] The sliding agent can, for example, be a polyether siloxane copolymer.

[0094] Advantageously, the first component of the kit according to the invention is essentially devoid of (or even does not include) mineral fillers and additives. In certain embodiments, in the first component, the total weight content of fillers minerals and additives is less than 5% (e.g., less than 2%), relative to the total weight of the first component.

[0095] Advantageously, the second component of the kit according to the invention further comprises one or more mineral fillers and / or one or more additives. More particularly, the second component of the kit according to the invention may further comprise one or more (preferably all) ingredients selected from:

[0096] - one or more mineral fillers (typically chosen from those mentioned) (above), preferably in a weight content of 5 to 75%, or even 15 to 55%, relative to the total weight of the second component,

[0097] - one or more dispersing agents (typically chosen from those mentioned) (above), preferably in a weight content of 0.1 to 2%, or even 0.2 to 1%, relative to the total weight of the second component,

[0098] - one or more defoaming agents (typically chosen from those mentioned) (above), preferably in a weight content of 0.1 to 2%, or even 0.2 to 1%, relative to the total weight of the second component,

[0099] - one or more pigments (typically chosen from those mentioned above), preferably in a weight content of 5 to 50%, or even 10 to 30%, relative to the total weight of the second component,

[0100] - one or more sliding agents (typically chosen from those mentioned) above), preferably in a weight content of 0.1 to 2%, or even 0.2 to 1% relative to the total weight of the second component.

[0101] The kit according to the invention is particularly suitable for forming a protective coating on a pipe or tank element made of cast iron (in particular ductile iron or grey cast iron, preferably ductile iron), steel or concrete.

[0102] Another object of the present invention is therefore a method for protecting a raw cast iron (in particular ductile iron or grey cast iron, preferably ductile iron), steel or concrete pipe or tank element, said method comprising the following steps:

[0103] a) bringing said first component and said second component of a kit as defined in this application into contact, thus forming a mixture;

[0104] b) the application of said mixture to at least part of an outer wall and / or at least part of an inner wall of a raw cast iron, steel or concrete pipe or tank element, thus forming an intermediate coating; and

[0105] c) the hardening of said intermediate coating, thus forming the protective coating.

[0106] Preferably, said mixture is applied in step b) to at least a portion of an outer wall of the raw cast iron pipe or tank element, in steel or concrete, and possibly on at least part of an internal wall of the raw cast iron, steel or concrete pipe or tank element.

[0107] In particular, when said raw cast iron, steel or concrete pipe or tank element is a pipe (in particular of circular cross-section), in particular a push-fit pipe, said mixture is advantageously applied to at least a part of an outer wall, at the level of at least one end of said pipe, and generally over the entire outer circumference of said part of outer wall.

[0108] The application of the mixture to "at least a part of an outer wall, at the level of at least one end of said pipe" advantageously means that the application is made over a length representing at least 1% (e.g. at least 2%, e.g. at least 5%, e.g. at least 10%, and preferably at most 40%) of the total length of the pipe, measured longitudinally from the edge of the pipe (and generally over the entire outer circumference of said length of pipe).

[0109] The application of the mixture to "at least a part of an outer wall, at the level of at least one end of said pipe" advantageously means that the application is made over a length representing at least 5 cm (e.g. at least 10 cm, e.g. at least 15 cm, and preferably at most 30 cm) of the total length of the pipe, measured longitudinally from the edge of the pipe, for a pipe having a length of at least 50 cm, for example from 90 cm to 10 m (and generally over the entire outer circumference of said length of pipe).

[0110] The application of the mixture in step b) can be carried out by any suitable technique, such as using a brush, paintbrush, roller or by spraying. The application can be carried out in one or more coats (for example two coats), preferably in a single coat.

[0111] The process according to the invention can be carried out in ambient air, at ambient temperature, and without external heating. Typically, the process according to the invention is carried out at a temperature between 15 and 35°C.

[0112] The curing time in step c) is typically between 5 and 60 minutes, preferably between 10 and 30 minutes.

[0113] The protective coating (i.e., the final, hardened coating) advantageously has a thickness of 120 to 600 µm, preferably 130 to 500 µm, in particular 135 to 400 µm, for example 140 to 300 µm, or even 145 to 270 µm. The coating thickness can be determined, in particular, by means of a thickness gauge.

[0114] Another object of the present invention is a coated pipe or tank element comprising:

[0115] - a raw cast iron pipe or tank element (in particular cast iron ductile or grey cast iron (preferably ductile cast iron), steel or concrete, and

[0116] - a protective coating located on at least part of an exterior wall and / or on at least part of an inner wall (preferably, at least part of the outer wall) of the raw piping or tank element,

[0117] said protective coating being formed from a kit as defined in this application. Said protective coating is typically formed by implementing the protection process according to the invention.

[0118] Advantageously, said protective coating has a thickness of 120 to 600 pm, preferably 130 to 500 pm, in particular 135 to 400 pm, for example 140 to 300 pm, or even 145 to 270 pm.

[0119] In the process according to the invention and in the coated pipe or tank element according to the invention, said raw pipe or tank element is preferably made of cast iron (in particular ductile iron or grey cast iron, preferably ductile iron) or steel, even better cast iron.

[0120] The present invention also relates to a pipeline or tank comprising one or more coated pipeline or tank elements as defined in this application.

[0121] Said pipeline or reservoir is preferably intended for the supply, distribution or storage of drinking water or wastewater (preferably wastewater).

[0122] The present invention is illustrated, in a non-limiting manner, by the following examples. EXAMPLES

[0123] A protective coating of 250 pm was formed by mixing 1 part of the first component by volume (for 1 part by mass) and 2 parts by volume of the second component (i.e. 2.5 parts by mass) of the kit described in Table 1 below, and then by applying it to a cast iron pipe.

[0124] The polyaspartic ester (La) and the polyaspartic ester (Il-a) shown below were used:

[0125] [Chem.8]

[0126] [Tables 1] First component Ingredient % weight / weight of first component 1,6-Hexamethylene diisocyanurate trimer 100 Second component Ingredients % wt / wt second component (La) + (ILa), mass ratio: 25 / 75 32.10 Dispersing agent (Tego dispers 652®) 0.90 Defoaming agent (BYK 1811®) 0.40 Red pigment 14.20 Mineral fillers (Talc + barium sulfate) 52.0 Glide agent (Tego Glide 410®) 0.40

[0127] The curing time (at 20°C, without external heating) and the chemical resistance of the coating described above were evaluated and compared to an epoxy-type coating (Table 2).

[0128] To measure the curing time, a wet coating was formed on the substrate using a 250 µm applicator to obtain a wet film of uniform thickness and appearance. A 220 g weight (with a surface area of ​​320 mm² and a square shape) was then applied to the film for 30 seconds at various time intervals. Curing was considered complete when the weight no longer left any marks on the film.

[0129] For chemical resistance testing, loose films were produced with the formulated paint. After complete hardening, these films were placed in a pH1 solution at room temperature. The film's mass change was monitored gravimetrically for 30 days. After 30 days, the films were oven-dried at 110°C to measure the amount of material extracted during immersion.

[0130] [Tables2] Epoxy-type coating Coating according to the invention Curing time 110 min 15 min Extraction rate (%) 0.2% 0.1%

[0131] The results of the tests in Table 2 demonstrate that the coating according to the invention has a better curing time than the epoxy-type coating and excellent chemical resistance.

[0132] For the insertion force, a 200 µm coating was formed on the outer surface at the end of a cut made in the male end (or plain end) of a cast iron pipe (nominal diameter = 150 mm), using the kit described in the Table 1. The coating was formed over the entire circumference of the pipe and over a length of 15 cm (measured longitudinally from the edge of the pipe).

[0133] After the coating had formed and hardened, the coated section was inserted into the female end (or push-fit end) of another cast iron pipe using a press equipped with a force sensor, and the push-fit forces were measured.

[0134] [Tables3] Epoxy-type coating. Coating according to the invention. Interlocking force: 4850 N, 1850 N

[0135] The results in Table 3 demonstrate that the use of a coating according to the invention makes it possible to significantly reduce the interlocking effort, compared to epoxy resin-based coatings.

Claims

Demands

1. Kit comprising: - a first component comprising a polyisocyanate; and - a second component comprising a polyaspartic ester of formula (I) and a polyaspartic ester of formula (II): [Chem.9] J < v.-GR VUW ° 0 (H), where: - in formula (I), each R is a C1-C6 alkyl and X is a C3-C12 acyclic aliphatic divalent group; - in formula (II), each R' is a C1-C6 alkyl and X' is a C6-C18 cyclic divalent group or a C6-C18 aliphatic divalent group comprising at least one C3-C12 cyclic group.

2. Kit according to claim 1, wherein the polyisocyanate is a triisocyanate, such as the isocyanurate trimer of 1,6-hexamethylene-diisocyanate.

3. Kit according to claim 1 or 2, wherein, in formula (I): - each R is a C1-C3 alkyl, preferably an ethyl, and - X is a C4-C8 alkylene, preferably branched.

4. Kit according to any one of claims 1 to 3, wherein, in formula (II): - each R' is a C1-C3 alkyl, preferably an ethyl, and - X' is a C6-C16 aliphatic divalent group comprising at least one C5-C12 cycloalkylene group.

5. Kit according to any one of claims 1 to 4, wherein the polyaspartic ester of formula (I) is represented as follows: [Chem. 10] \ X / Y il 0 H 1 HO and the polyaspartic ester of formula (II) is represented as follows: [Chem. 11]

6. ORH 0 Kit according to any one of claims 1 to 5, wherein the mass ratio of the polyaspartic ester of formula (I) to the polyaspartic ester of formula (II) is 0.05 to 1, preferably 0.1 to 0.8, or even 0.2 to 0.5, or even 0.3 to 0.

4.

7. Kit according to any one of claims 1 to 6, wherein the mass ratio of the sum of polyaspartic esters of formula (I) and formula (II) to polyisocyanate is 0.4 to 1.5, preferably 0.5 to 1.3, or even 0.6 to 1.2 or even 0.6 to 1.

1.

8. Kit according to any one of claims 1 to 7, wherein the second component does not comprise an aromatic amine or if it does, then the aromatic amine content is less than 2% by weight, or even less than 1% by weight, relative to the total weight of the second component.

9. Coated pipe or tank element comprising: - a raw pipe or tank element of cast iron, steel or concrete, - a coating located on at least a portion of an outer wall and / or on at least a portion of an inner wall of the raw pipe or tank element, said protective coating being formed from a kit as defined in any one of claims 1 to 8.

10. Pipeline or tank comprising one or more coated pipeline or tank elements as defined in claim 9, the pipeline or tank preferably being intended for the supply, distribution or storage of drinking water or wastewater.

11. A method for protecting a raw cast iron, steel, or concrete pipe or tank element comprising: a) bringing said first component and said second component of a kit as defined in any one of claims 1 to 8 into contact, thereby forming a mixture; b) applying said mixture to at least a part of an outer wall and / or at least a part of an inner wall of the raw cast iron, steel, or concrete pipe or tank element, thereby forming an intermediate coating; and c) hardening said intermediate coating, thereby forming the protective coating.

12. A method according to claim 11, wherein said mixture is applied in step b) to at least a portion of an outer wall of the raw cast iron, steel or concrete pipe or tank element and optionally to at least a portion of an inner wall of the raw cast iron, steel or concrete pipe or tank element.