Polyol catalyst for two-component polyurethane systems

Abstract

Polyol catalyst for a two-component polyurethane system. The present invention relates to a polyol catalyst for the production of polyurethanes comprising: - at least two alcohol functional groups, - at least one catalyst functional group selected from imidazole and / or tertiary amine functional groups, - at least one urea functional group. The present invention also relates to a method for preparing a catalyst according to the invention. A two-component crosslinkable polyurethane composition comprising: a) a polyisocyanate component, b) a polyol component based on a polyol catalyst according to the invention, and optionally another polyol component free of a catalyst functional group selected from imidazole and / or tertiary amine functional groups, is also part of the invention.Finally, the invention relates to a coating composition based on a two-component crosslinkable polyurethane composition according to the invention, a method for preparing such a coating, and a substrate coated with a two-component crosslinkable polyurethane composition according to the invention.

Description

Title of the invention: Polyol catalyst for a two-component polyurethane system. Technical field

[0001] The present invention relates to the field of two-component polyurethane coatings based on organic solvents or aqueous dispersion.

[0002] More particularly, the invention relates to a polyol catalyst for the formation of two-component polyurethane coatings, a process for preparing such a catalyst, its use as a catalyst or as a polyol component in a two-component crosslinkable polyurethane composition, a two-component crosslinkable polyurethane composition and its final applications. Previous technique

[0003] Polyurethanes constitute one of the most important classes of polymeric materials. They are generally prepared by contacting two products: a polyol (binding resin) and a polyisocyanate (crosslinking agent). The reaction at room temperature between these two products is slow and requires the addition of a catalyst, most often a tin-based metal, to form the two-component polyurethane coating.

[0004] Polyurethane coatings are known for their excellent performance in terms of chemical resistance, heat resistance, and water resistance, and are widely used in industrial coatings. By appropriately selecting the polyol component, the polyisocyanate component, and the catalyst, it is even possible to impart specific properties to the polyurethane coating, depending on the desired end performance, for example, in terms of flexibility or transparency.

[0005] However, the use of metallic catalysts, particularly tin-based ones, in the reaction between the polyol and the polyisocyanate poses problems of toxicity, safety, and harmfulness to human health and the environment in general. The disposal of these catalysts is often extremely difficult and very costly, which is a significant drawback for most of the applications concerned.

[0006] Furthermore, aqueous dispersion polyurethanes have been developed at the expense of organic solvent-based polyurethanes to reduce emissions of volatile organic compounds (VOCs) into the atmosphere. However, in aqueous media, tin-based catalysts lead to secondary reactions between isocyanate groups and water, requiring the use of a larger quantity of catalyst, and thus diminishing the original advantage of aqueous polyurethanes.

[0007] Thus, over the last decade, ecological approaches have been developed for the synthesis of more sustainable polyurethanes.

[0008] EP 1 022 298 B1 describes catalysts for the manufacture of polyurethanes obtained by reaction between (a) polymer compounds containing carboxylic acid and / or anhydride groups with (b) compounds having at least one primary or secondary amino group and / or with compounds having a tertiary amino group and at least one group that reacts with acid or anhydride groups. This reaction is not complete; compounds having at least one free amino group do not react, leading to a strong odor. Another drawback of the polymer compounds used in this reaction is their very high molar mass, and therefore their high viscosity, requiring the use of large quantities of diluent.

[0009] EP 0 046 088 B1 describes the use of polyoxyalkylene polyamines as curing agents for the formation of polyurethane by reacting polyoxyalkylene polyamines with acrylic acid derivatives or alpha-substituted acrylic acids having terminal hydroxyl groups, optionally in the presence of a compound having an oxirane ring. However, the polyisocyanates used are primarily aromatic, and the proposed catalytic functions are poorly reactive with aliphatic isocyanates.

[0010] The use of tertiary amines as a catalyst for the manufacture of polyurethanes has also been studied, but their migration within the coating film remains, which alters the final performance of the coating (H. Sardon et al., Macromolecules 2015, 48, 3153-3165).

[0011] Given their toxicity, the metallic catalysts used in the preparation of polyurethanes need to be replaced by catalysts that are less toxic to humans and the environment, capable of reducing the formation time of a coating film, and that do not migrate within the coating over time.

[0012] The technical problem to be solved by the present invention therefore consists in the development of a reaction catalyst between a polyol and a polyisocyanate which is environmentally friendly and does not use toxic compounds, while having improved mechanical performance and a time of use (ease of use) or at least comparable to those of tin-based catalysts.

[0013] The invention therefore aims to provide an environmentally friendly catalyst for the reaction between a polyol and a polyisocyanate, free of toxic compounds, and which also exhibits improved mechanical performance, particularly in terms of hardness and chemical resistance, due to the presence of urea groups, compared to conventional tin-based catalysts. The catalyst of the invention also allows the preparation of polyurethanes in both mediums solvent-based and aqueous, and more specifically in aqueous environments to reduce VOC emissions into the atmosphere.

[0014] The catalyst of the invention also has the advantage of being covalently grafted onto the polyurethane, and thus integrated into the very structure of the polyurethane, thereby preventing any migration out of the polyurethane over time. This advantageously reduces odor and VOC emissions associated with the use of conventional tertiary amines.

[0015] Finally, the catalyst of the invention has low polydispersity and low viscosity, which makes the coating composition in which it is integrated easy and quick to apply, without additional heat input (low energy consumption process). Description of the invention

[0016] The first object of the present invention therefore relates to a polyol catalyst comprising: - at least two alcohol functions, and preferably two alcohol functions, - at least one catalyst function chosen from among the imidazole and / or tertiary amine functions, and preferably at least two catalyst functions chosen from among the imidazole and / or tertiary amine functions, - at least one urea function, and preferably at least two urea functions.

[0017] The polyol catalyst can in particular be suitable for catalyzing the urethanization reaction between an alcohol function and an isocyanate function, in particular the polyol catalyst is suitable for the production of polyurethanes.

[0018] The polyol catalyst comprises at least one catalyst function. Preferably, the polyol catalyst comprises at least two catalyst functions, which may be identical or different. For the purposes of the present invention, a catalyst function is a function capable of catalyzing the urethanation reaction between an alcohol function and an isocyanate function.

[0019] At least one catalyst function is chosen from among the imidazole and / or tertiary amine functions.

[0020] The tertiary amine function may, in particular, have a pKa > 9, preferably a pKa > 10. The tertiary amine function advantageously conforms to the formula -NRiR2 in which Ri and R2, identical or different, represent a Cl-C4 alkyl or a cycloalkyl, or Ri and R2, together with the nitrogen atom to which they are bonded, form a C2-C6 heterocycle.

[0021] The imidazole function may in particular correspond to the following formula:

[0022] wherein R3, R4 and R5 are independently chosen from H, alkyl, aryl and alkylaryl or R4 and R5 together with the carbon atoms to which they are bonded can form a ring.

[0023] For the purposes of the invention, the following definitions apply: - Alkyl: a saturated aliphatic hydrocarbon group, linear or branched. A C1-C4 alkyl means an alkyl having from 1 to 4 carbon atoms. The term "branched" means that at least one alkyl group such as a methyl or ethyl group is attached to a linear alkyl chain. Examples of alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, and n-pentyl; - Cycloalkyl: a saturated hydrocarbon ring possibly substituted by one or more alkyl groups. Examples of cycloalkyls are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or isobornyl; - Heterocycle: a ring (preferably non-aromatic) in which at least one ring atom is a heteroatom, preferably chosen from O, N, or S, more preferably N or O. A C2-C6 heterocycle means a heterocycle having from 2 to 6 carbon atoms. A heterocycle may optionally be substituted by one or more alkyl groups, or two ring atoms may be linked by an alkylene bridge to form a polycyclic heterocycle. Examples of heterocycles are morpholine, piperidine, pyrrolidine, or quinuclidine; - Aryl: an aromatic group. An aryl may contain a single ring or several rings, at least one of which is aromatic. Examples of aryls are phenyl, naphthyl, or biphenyl; - Alkylaryl: an alkyl group as defined above substituted by an aryl group. An example of an alkylaryl is benzyl.

[0024] The polyol catalyst comprises at least one urea function. Preferably, the polyol catalyst comprises at least two urea functions.

[0025] A urea functional group may, in particular, be a substituted urea functional group. For the purposes of this invention, a substituted urea functional group is a urea functional group having at least one nitrogen atom that does not bear a hydrogen atom. Preferably, a substituted urea functional group may correspond to the formula *-NR6-C(=O)-NH-* in which R6 is a substituent other than H, and the symbols * each represent a point of attachment to a carbon atom.

[0026] A substituted urea function may, in particular, have a substituent R6 resulting from an aza-Michael reaction between a primary amine and a compound functionalized with at least one (meth)acrylate group, preferably a compound functionalized with at least one acrylate group, more preferably a compound functionalized with a single acrylate group. In particular, R6 may comprise a motif of the formula #-CH2-CH2-C(=O)-O-§ in which # represents an attachment point to the nitrogen atom of the substituted urea function and § represents an attachment point to a carbon atom.

[0027] A substituted urea function may, in particular, have a substituent Z bearing at least one catalytic function as defined above. In particular, Z may be a group of formula -A'-(CAT)P in which: A' is an alkylene or an alkylene comprising at least one heteroatom, preferably a C2-C6 alkylene, p is 1 or 2, and preferably 1; CAT is a catalyst function as defined above.

[0028] For the purposes of the invention, the following definitions apply: - Alkylene: an aliphatic radical derived from an alkane with the formula CmH2m+2, where m = 1 to 50, by removing a hydrogen atom from each attachment point of the radical. An alkylene can be linear or branched. An alkylene can be divalent, trivalent, tetravalent, pentavalent, or hexavalent. A C2-C6 alkylene means an alkylene with 2 to 6 carbon atoms. - Alkylene comprising at least one heteroatom: an alkylene in which at least one carbon atom is replaced by a heteroatom, in particular chosen from O, N or S, preferably N.

[0029] According to an advantageous embodiment, a substituted urea function corresponds to the formula Z-NR6-C(=O)-NH-* in which R6 and Z are as defined above and the symbol * represents an attachment point to a carbon atom.

[0030] According to a preferred embodiment, the polyol catalyst of the invention corresponds to the following formula (1): (1) in which: -1 is the residue of a polyisocyanate, - Z is a group comprising at least one catalyst function as defined above, - A is the residue of a polyol, and preferably A is a C2-C12 alkylene possibly alkoxylated or esterified, for example by an ester function from the opening of a lactone such as caprolactone, - a = 1 to 5, and -b = 2 to 3.

[0031] In the formula (1) of the polyol catalyst of the invention, I is advantageously the residue of a diisocyanate.

[0032] In the formula (1) of the polyol catalyst of the invention, Z is advantageously a group of formula -A'-(CAT)P as defined above.

[0033] In the formula (1) of the polyol catalyst of the invention, Z is advantageously the residue of a polyol selected from: ethylene glycol, 1,2- or 1,3-propylene glycol, 1,2-, 1,3- or 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 3,3-dimethyl-1,5-pentanediol, neopentyl glycol, 2,4-diethyl-1,5-pentanediol, cyclohexanediol, cyclohexane-1,4-dimethanol, Norbornane dimethanol, norbornane dimethanol, tricyclodecanediol, tricyclodecane dimethanol, bisphenol A, B, F or S, hydrogenated bisphenol A, B, F or S, trimethylolmethane, trimethylolethane, trimethylolpropane, di(trimethylolpropane), triethylolpropane, pentaerythritol, dipentaerythritol, glycerol, di-, tri- or tetraglycerol, di-, tri- or tetraethylene glycol, di-, tri- or tetrapropylene glycol, di-, tri- or tetrabutylene glycol,a polyethylene glycol preferably having a weight molecular weight Mw of 200 to 10000 g.mol1, a polypropylene glycol preferably having a weight molecular weight Mw of 200 to 10000 g.mol1, a polytetramethylene glycol preferably having a weight molecular weight Mw of 200 to 10000 g.mol1, a poly(ethylene glycol-co-propylene glycol) preferably having a weight molecular weight Mw of 200 to 10000 g.mol1, an alditol (i.e. erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, glactitol, fucitol or iditol), a dianhydrohexitol (i.e. isosorbide, isomannide or isoidide), tris(2-hydroxyethyl)isocyanurate, a polybutadiene polyol preferably having a weight molecular weight Mw of 200 at 10000 g.mol1, a polyester polyol preferably having a weight molecular weight Mw ranging from 200 to 10000 g.mol1, a polyether polyol preferably having a weight molecular weight Mw ranging from 200 to 10000 g.mol1,a polyorganosiloxane polyol preferably having a weight molecular weight Mw ranging from 200 to 10000 g.mol1, a polycarbonate polyol preferably having a weight molecular weight Mw ranging from 200 to 10000 g.mol1, as well as alkoxylated derivatives (e.g. ethoxylated and / or propoxylated) of these, and derivatives obtained by ring-opening polymerization of a lactone (e.g. e-caprolactone) initiated with one of the aforementioned polyols.

[0034] In the formula (1) of the polyol catalyst of the invention, a is advantageously equal to 1.

[0035] In the formula (1) of the polyol catalyst of the invention, b is advantageously equal to 2.

[0036] The second object of the invention relates to a process for preparing a catalyst according to the invention comprising the following steps: (i) Michael reaction between at least one hydroxylated (meth)acrylate monomer and at least one monomer having at least one primary amine function and at least one catalyst function as defined above, and (ii) reaction between the amino-ester compound obtained at the end of step (i) with a polyisocyanate, to form a polyol catalyst with at least one urea functional group.

[0037] For the purposes of the invention, a hydroxylated (meth)acrylate monomer is a compound functionalized by at least one (meth)acrylate group (i.e., a group of the formula -OC(=O)-CHR'=CH2 in which R' is hydrogen or methyl) and at least one hydroxyl group (-OH). A hydroxylated (meth)acrylate monomer may, in particular, be functionalized by at least one acrylate group (R' = H), preferably functionalized by a single acrylate group. A hydroxylated (meth)acrylate monomer may, in particular, be functionalized by at least one hydroxyl group, preferably functionalized by 1, 2, 3, 4, or 5 hydroxyl groups, more preferably functionalized by a single hydroxyl group. More preferably, a hydroxylated (meth)acrylate monomer is a compound functionalized by a single acrylate group and a single hydroxylated group.

[0038] According to a preferred embodiment, the hydroxylated (meth)acrylate monomer implemented in step (i) is selected from 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3-chloro-2-hydroxypropyl acrylate, glycerin monoacrylate, trimethylolpropane monoacrylate, di(trimethylolpropane) monoacrylate, trimethylolethane monoacrylate, pentaerythritol monoacrylate, dipentaerythritol monoacrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polyethylene-co-polypropylene glycol monoacrylate, polytetramethylene glycol monoacrylate, a polycaprolactone (meth)acrylate conforming to the following formula (2): R p Jx X V 0( x"" | H One (2)

[0039] in which R represents H or methyl, and n = 1 to 10, or mixtures thereof.

[0040] According to an even more preferred embodiment, the hydroxylated (meth)acrylate monomer implemented in step (i) is selected from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, a polycaprolactone (meth)acrylate corresponding to formula (2) above, or mixtures thereof.

[0041] The monomer having at least one primary amine function and at least one catalyst function implemented in step (i) may further optionally include at least one secondary amine function.

[0042] According to a preferred embodiment, the monomer having at least one primary amine function and at least one catalyst function implemented in step (i) is selected from N,N-dimethylethylenediamine, N,N-diethylethylenediamine, dimethylaminopropylamine (DMAPA), 3-(diethylamino)-1-propylamine (DEAPA), 4-(dimethylamino)-1-butylamine, 4-(diethylamino)-1-butylamine, 5-(dimethylamino)-1-pentylamine, N,N-dimethyldipropylenetriamine (DMAPAPA), N-(2-aminoethyl)-N-methylcyclohexanamine, 2-morpholinoethylamine, 3-morpholinopropylamine, 2-piperidinoethylamine, 3-piperidinopropylamine, 5-piperidinopentylamine, 2-(4-methyl-l-piperidinyl)ethanamine, 2-pyrrolidinoethylamine, 3-pyrrolidinopropylamine, 2-(2-aminoethyl)-l-methylpyrrolidine, 2-(4-methyl-piperazin-l-yl)-ethylamine, l-(3-aminopropyl)imidazole, l-(3-aminopropyl)-2-methyl-lH-imidazole, l-(4-aminobutyl)imidazole, or mixtures thereof.

[0043] According to an even more preferred embodiment, the monomer having at least one primary amine function and at least one catalyst function implemented during step (i) is chosen from dimethylaminopropylamine (DMAPA), 3-(diethylamino)-l-propylamine (DEAPA), N,N-dimethyldipropylenetriamine (DMAPAPA), l-(3-aminopropyl)imidazole, or mixtures thereof.

[0044] According to a preferred embodiment, the polyisocyanate used in step (ii) is selected from isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane 4,4'-diisocyanate (4,4'-MDI), dicyclohexylmethane 4,4'-diisocyanate, tetramethylxylene diisocyanate (TMXDI), hydrogenated tetramethylxylene diisocyanate, hexamethylene diisocyanate (HDI), norborane diisocyanate (NBDI), trimethylenehexamethylene diisocyanate, the 1,5-naphthylene diisocyanate, the biuret, allophonate and isocyanurate forms of these polyisocyanates, or mixtures thereof.

[0045] According to an even more preferred embodiment, the polyisocyanate used in step (ii) is chosen from isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), or mixtures thereof.

[0046] In a preferred embodiment, the molar ratio between the primary amine functions of step (i) and the isocyanate functions varies from 0.8 to 1.2, and preferably is about 1, in order to obtain a polyol catalyst that is not very polydisperse, and therefore not very viscous.

[0047] The process of the invention may also include an intermediate step between steps (i) and (ii) aimed at consuming any remaining residual primary amines that did not react during step (i). This intermediate step may consist of adding a (meth)acrylate monomer, which may be identical or different from the hydroxylated (meth)acrylate monomer used in step (i). The (meth)acrylate monomer added during this intermediate step is preferably a mono- or multifunctional (meth)acrylate monomer such as 1,6-hexanediol diacrylate (HDDA), tert-butylcyclohexyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, lauryl acrylate, isobornyl acrylate, 3-methyl-1,5-pentanediol diacrylate, 1,10-decanediol diacrylate, tricyclodecanedimethanol diacrylate, di(trimethylolpropane) tetraacrylate.

[0048] The process of the invention may also include the addition of a monomer having at least one primary amine function and at least one alcohol function, such as ethanolamine or a (poly)alkylene glycol hydroxyamine of the formula NH2-[Alk-O]q-Alk-OH, in which each Alk is a C2-C4 alkylene (in particular ethylene, propylene, or tetramethylene) and q ranges from 1 to 30 (in particular from 1 to 10). The addition of such a monomer can, in particular, increase the number of alcohol functions of the polyol catalyst, and thus the crosslinking density of the polyurethane system. Preferably, the monomer having at least one primary amine function and at least one alcohol function is added in step (i), and more preferably at the same time as the monomer having a primary amine function and a catalyst function.In this embodiment, the weight ratio between the monomer having at least one primary amine function and at least one catalyst function and the monomer having at least one primary amine function and at least one alcohol function varies from 0.1 to 100%, and preferably between 30 and 70%.

[0049] A third object of the present invention relates to the use of a polyol catalyst according to the invention: - either as a catalyst in a two-component crosslinkable polyurethane composition comprising a polyisocyanate component and a polyol component, - either as a polyol component in a two-component crosslinkable polyurethane composition comprising, in addition, a polyisocyanate component and, optionally, another polyol component free of catalyst function chosen from the imidazole and / or tertiary amine functions.

[0050] When the polyol catalyst of the invention is used as a catalyst in a two-component crosslinkable polyurethane composition comprising a polyisocyanate component and a polyol component, it is preferably used in an amount ranging from 10 to 100% by weight relative to the total weight of the polyol component.

[0051] When the polyol catalyst of the invention is used as a polyol component in a two-component crosslinkable polyurethane composition comprising, furthermore, a polyisocyanate component and, optionally, another polyol component free of catalyst function, it is preferably used in an amount ranging from 0.1 to 10% by weight relative to the total weight of the polyol component.

[0052] Thus, the fourth object of the invention relates to a two-component crosslinkable polyurethane composition comprising: a) a polyisocyanate component, b) a polyol component comprising: bl) from 0.1 to 100% by weight, relative to the total weight of the polyol component, of a polyol catalyst according to the invention, and b2) from 0 to 99.9% by weight, relative to the total weight of the polyol component, of another polyol component free of catalyst function selected from the imidazole and / or tertiary amine functions.

[0053] The polyisocyanate component a) preferably has a functionality greater than or equal to 3, more preferably greater than 2, and even more preferably equal to 3.

[0054] The polyol component b) preferably has an IOH index between 200 and 300 mg KOH / g, more preferably between 50 and 200 mg KOH / g, and even more preferably between 80 and 150 mg KOH / g.

[0055] In a first preferred embodiment, the polyol component of the two-component polyurethane crosslinkable composition of the invention may comprise: bl) from 0.1 to 10% by weight, and preferably between 1 and 7% by weight, relative to the total weight of the polyol component, of a polyol catalyst according to the invention, and b2) 90 to 99.9% by weight, and preferably between 93 and 99% by weight, relative to the total weight of the polyol component, of another polyol component free of catalyst function selected from the imidazole and / or tertiary amine functions.

[0056] In a second preferred embodiment, the polyol component of the two-component polyurethane crosslinkable composition of the invention may comprise: bl) from 10 to 100% by weight, relative to the total weight of the polyol component, of a polyol catalyst according to the invention, and b2) from 0 to 90% by weight, relative to the total weight of the polyol component, of another polyol component free of catalyst function selected from the imidazole and / or tertiary amine functions.

[0057] According to a particularly preferred embodiment of the invention, the two-component polyurethane crosslinkable composition of the invention is free of metallic catalyst, and in particular is free of tin-based catalyst.

[0058] The two-component polyurethane crosslinkable composition of the invention is advantageously a coating composition, and more particularly an aqueous coating composition, preferably selected from paint, varnish, ink, adhesive, glue compositions, and more preferably an aqueous paint or varnish composition. In particular, the two-component polyurethane crosslinkable composition of the invention can be a protective coating composition, in particular a finishing coating composition or an anti-corrosion coating composition, or a decorative coating composition.These coating compositions are particularly suitable for applications in the following fields: railway construction and renovation, automotive, road transport, marine, aeronautical, agricultural machinery, public works equipment, wind turbines, oil platforms, containers, metal buildings, metal reinforcements or coils, or building including furniture, parquet flooring, joinery and frameworks.

[0059] Another object of the invention relates to a method for preparing a coating comprising a step of applying a two-component, crosslinkable polyurethane composition according to the invention onto a substrate, followed by a step of drying said composition, preferably at room temperature (20°C). The application of the two-component, crosslinkable polyurethane composition according to the invention can be carried out by means of a brush, a roller, a spray, or by dipping.

[0060] The two-component polyurethane crosslinkable composition of the invention is preferably applied to a substrate chosen from among metal, glass, wood, including chipboard and plywood, plastic, metal, concrete, plaster, composite, textile substrates.

[0061] Finally, the last object of the invention relates to a substrate coated with a two-component crosslinkable polyurethane composition according to the invention, preferably chosen from substrates made of metal, glass, wood, including chipboard and plywood, plastic, metal, concrete, plaster, composite, textile.

[0062] In addition to the foregoing provisions, the invention also includes other provisions which will become apparent from the following supplementary description, which relates to examples of the preparation of polyol catalysts according to the invention, and to the evaluation of crosslinkable two-component polyurethane compositions including them, and in [Fig.1] and [Fig.2]. Brief description of the Figures

[0063] [Fig.1] Fig.1 is a graph showing the gloss retention at an angle of 20° over time of different reference and invention two-component polyurethane systems.

[0064] [Fig.2] Fig.2 is a graph representing the (AE* ab) coloring over time of different two-component polyurethane systems of reference and according to the invention. Examples

[0065] Methods for measuring and evaluating application performance: In this application, the following methods for measuring and evaluating application performance were used:

[0066] Amine index: The amine value was measured by titration using a Metrohm titrimeter (848 titrino plus) equipped with a Metrohm reference measuring probe 6.0262.100. The sample to be analyzed was weighed in a 100 mL beaker. 50 mL of dichloromethane was added. The sample was completely dissolved by magnetic stirring. The titration was carried out under magnetic stirring with 0.1 N perchloric acid in acetic acid, according to the operating procedure of the chosen titrimeter. The amine value was calculated using the following equation: VE x NT x 56.1 Umine (mg KOH / g) =-----------

[0067] in which: VE = Volume of titrant added for sample analysis (mL), NT = Normality of the titrant (0.1 N), and M = Mass of the sample (g).

[0068] Pot life: Pot life is the time it takes for a varnish composition to double in viscosity. Viscosity is measured regularly over time. These measurements allow for the plotting of a linear regression line, which is used to calculate the composition's pot life. This standard measurement helps determine the ideal operating range of the composition without compromising its application properties.

[0069] Dust-free drying: Dust-free drying is measured according to standard NF EN ISO 9117-3:2010. Using a filmograph, a varnish composition approximately 40-50 µm thick (dry thickness) is applied to a QD412 steel plate (in a room (The film is air-conditioned to 23°C and 50% relative humidity.) It is then placed in contact with calibrated micrometric glass beads (125 / 250 µm particle size). After a contact time of 10 seconds, the plate is tilted and then dusted with a brush at varying intervals until the beads are completely detached from the varnish surface. The time at which the beads no longer adhere to the surface corresponds to the dust-free drying stage.

[0070] Persoz Hardness:

[0071] The Persoz hardness is measured according to standard NF EN ISO 1522 of March 2007. The Persoz hardness is measured after applying a varnish composition approximately 40-50 µm thick (dry thickness) to a QD46 steel plate using a filmograph (in a climate-controlled room at 23°C and 50% relative humidity). The measurement is the pendulum's damping time in seconds between 12 and 4°. The pendulum balls are placed on the varnish-coated plate. The damping time is recorded using an automatic counter. Measurements are taken at regular intervals to monitor the hardness development.

[0072] Chemical resistance: Chemical resistance is evaluated after applying a varnish composition approximately 40-50 µm thick (dry thickness) to a QD46 steel plate using a filmograph (in a climate-controlled room at 23°C and 50% relative humidity). Chemical resistance is measured using a Taber® 5750 linear abrasive after the film has dried for 7 days in a climate-controlled room at 23°C and 50% relative humidity. The resistance of the varnish film to methyl ethyl ketone (MEK) is evaluated by the time required (in seconds) for the varnish surface to wear away with a 1 kg weight equipped with a cotton wick soaked in MEK, moving back and forth over the coating under test until the varnish is completely destroyed. The speed of the sliding axis is fixed. The cotton is moistened regularly.

[0073] Adhesion: Adhesion is measured according to standard NF EN ISO 2409:2013, after applying a varnish composition approximately 40-50 µm thick (dry thickness) to a QD46 steel plate using a filmograph (in a climate-controlled room at 23°C and 50% relative humidity). The adhesion test assesses the coating's resistance to separation from the substrate by creating a grid of incisions in the coating down to the substrate. Standard adhesive tape (3M Scotch® 2525-7.5 N / cm) is applied and firmly rubbed over the grid, then torn off at a 60° angle. Visual observation of the incised area allows for an assessment of the amount of coating remaining on the substrate. The rating is based on the standard's table. on a scale of 0 (good) to 5 (bad). Adhesion performance is monitored over time at 1, 7 and 14 days.

[0074] Accelerated UV aging (according to standard NF EN 927-6 of 2006):The device used is equipped with 313 nm UVB lamps (aggressive exposure to short wavelengths). Samples are exposed in a UV aging chamber (QUV Solar Eye - Labomat). Periods of light exposure alternate with periods of condensation: 4 hours with UV at 60°C, then 4 hours of condensation at 50°C. The accelerated UV aging test reveals defects such as yellowing, whitening, loss of gloss (gloss retention), cracking, delamination, chalking, etc., more quickly than outdoor exposure. The test is performed on an aluminum plate. In the primer / varnish system: a layer of epoxy primer with a dry thickness of 50 µm is applied to an aluminum plate, then a layer of the varnish to be tested with a dry thickness of 60 µm is applied, with a 24-hour application time between coats.In the DTM (Direct To Metal) varnish or paint system, a 60 µm dry-thickness layer of varnish or paint to be tested is applied directly to an aluminum plate. The coated aluminum plate is then stored for two days in a climate-controlled room (at 23°C and 50% relative humidity), then for two days in an oven at 50°C, and finally for a minimum of two days in a climate-controlled room (at 23°C and 50% relative humidity). The plate is then placed in the UV aging chamber. Gloss (and subsequent calculation of gloss retention) and the AE* ab color difference are monitored over time.

[0075] Color deviation AE* ab: The color difference is measured using a Minolta CM2600d spectrocolorimeter (illuminant D65 - daylight below 10°). In the color space L a* b*, a color is defined from 3 coordinates: L*: represents the value on a white-black axis, a*: represents the value on a green-red axis, b*: represents the value on a blue-yellow axis. The color difference AE* ab in the color space L a* b* is defined by the following equation: aE* ab ™ V (aL*) 2 + (âa*) 2 +( Ab*) 2 where AL*, Aa*, Ab* are the color difference values ​​between the sample and the reference color.

[0076] Brightness 20°: Gloss measurement at 20° is performed according to standard NF EN ISO 2813 (2014) (in a climate-controlled room at 23°C and 50% relative humidity). The gloss test evaluates the reflective properties of a coating film's surface by reflecting a beam of light directed at a specific angle. Gloss is measured using a reflectometer on samples prepared according to the Accelerated UV Aging Test described above. Average gloss retention is calculated based on the arithmetic mean of three residual gloss measurements (after aging) relative to the initial gloss (before aging).

[0077] Raw materials: The raw materials used for the preparation of the polyol catalysts according to the invention were as follows: - Dimethylaminopropylamine (DMAPA) from Sigma-Aldrich, - Tert-octylamine from Sigma-Aldrich, - Hexanediol diacrylate (HDDA) from Sartomer (trade name: SR238), - Sigma-Aldrich butyl acetate (BA), - Sigma-Aldrich's Hexamethylene Diisocyanate (HDI), - Isophorone diisocyanate (IPDI) from Covestro (trade name: Desmodur® I), and - 2-hydroxyethyl acrylate (2-HEA) from Sigma-Aldrich.

[0078] Example 1: Preparation of a polyol catalyst according to the invention Tert-octylamine (57.92 g, or 0.4455 mol) was introduced at 23°C into a reactor equipped with a reflux column, dropping funnel, thermometer, and angled paddle stirrer. 2-Hydroxyethyl acrylate (2-HEA) (74.21 g, or 0.6397 mol) was then introduced via the dropping funnel over a period of 15 minutes. During the introduction of 2-HEA, the temperature was maintained below 40°C by controlling the exothermic reaction with an ice-water bath. After the introduction of 2-HEA, the temperature was maintained at 40°C for 2 hours and 30 minutes. Dimethylaminopropylamine (DMAPA) (19.63 g, or 0.1925 mol) and butyl acetate (51.46 g) were then introduced and mixed into the dropping funnel. The mixture was then introduced into the reactor via the dropping funnel over a period of 20 seconds, and the temperature was subsequently raised and maintained at 60°C for 30 minutes. The resulting mixture was then cooled to 30°C.Hexamethylene diisocyanate (HDI) (53.88 g, or 0.3207 mol) was then added dropwise from a dropping funnel over a period of 1 hour. During the introduction of the HDI, the temperature was maintained below 50°C by controlling the exothermic reaction with an ice water bath. After the introduction of the HDI, the temperature was raised and then maintained at 80°C for 1 hour. The amine index was then measured at 84 mg KOH / g. Infrared (IR) analysis showed the total consumption of the initially present isocyanate groups.

[0079] Example 2: Preparation of a polyol catalyst according to the invention Dimethylaminopropylamine (DMAPA) (51.00 g, or 0.5000 mol) was introduced at 23°C into a reactor equipped with a reflux column, dropping funnel, thermometer, and angled paddle stirrer. 2-HEA (62.00 g, or 0.5345 mol) was added dropwise through the dropping funnel over a period of 1 hour and 30 minutes. During the addition of 2-HEA, the temperature was maintained below 50°C by monitoring the exothermic reaction with an ice-water bath. After the addition of 2-HEA, the temperature was maintained at 50°C for 30 minutes. Hexanediol diacrylate (HDDA) (7.50 g, i.e. 0.0332 mol) was then introduced through the dropping funnel over a period of 10 minutes, and the temperature was then raised and maintained at 75°C for 30 minutes. A proton NMR analysis shows that all of the 2-HEA, all of the HDDA and all of the DMAPA have been consumed. Butyl acetate (16.94 g) was then added via dropping funnel (over 5 minutes), and the temperature was lowered to 30°C. HDI (31.92 g, or 0.1900 mol) was then added dropwise via dropping funnel over a period of 1 hour. During the addition of the HDI, the temperature was maintained below 50°C by monitoring the exothermic reaction with an ice-water bath. After the addition of the HDI, the temperature was raised and then maintained at 80°C for 1 hour. The amine value was then measured at 202 mg KOH / g. Infrared (IR) analysis showed the total consumption of the initially present isocyanate groups.

[0080] Example 3: Preparation of a polyol catalyst according to the invention DMAPA (51.00 g, or 0.5000 mol) was introduced at 23°C into a reactor equipped with a reflux column, dropping funnel, thermometer, and angled paddle stirrer. 2-HEA (62.00 g, or 0.5345 mol) and HDDA (7.50 g, or 0.0332 mol) were introduced and mixed in the dropping funnel. The mixture was introduced into the reactor dropwise over a period of 1 hour and 30 minutes. During the introduction of the 2-HEA + HDDA mixture, the temperature was maintained below 50°C by monitoring the exothermic reaction with an ice-water bath. After the introduction of the 2-HEA + HDDA mixture, the temperature was maintained at 50°C for 1 hour. Butyl acetate (17.22 g) was added via dropping funnel (over 5 minutes), then the temperature was lowered to 30°C. HDI (23.94 g, or 0.1425 mol) was then added dropwise via dropping funnel over a period of 45 minutes.During the introduction of HDI, the temperature was maintained below 50°C by controlling exothermic reaction with an ice water bath. IPDI (10.55 g, or 0.0475 mol) was then added via dropping funnel over a period of 15 minutes. During the introduction of IPDI, the temperature was... The temperature was kept below 50°C by controlling the exothermic reaction with an ice water bath. The temperature was then raised and maintained at 80°C for 1 hour. The amine value was then measured at 197 mg KOH / g. Infrared (IR) analysis showed the total consumption of the initially present isocyanate groups.

[0081] Example 4: Preparation and evaluation of two-component polyurethane crosslinkable compositions according to the invention The polyol catalysts of the invention prepared in examples 1, 2 and 3, were tested in acrylic resin-based varnish compositions. The commercial resins used were as follows: - Synocure® 862 X 60 Resin: hydroxylated acrylic resin having an IOH of 1.55% relative to the resin mass with a high viscosity (5500-8000 mPa.s at 25°C) and a dry extract of 60% in xylene. - Synocure® 9293 BA 70 Resin: High solids hydroxylated acrylic resin having an Iqh of 2.9% relative to resin mass with low viscosity (1000-2000 mPa.s at 25°C) and a solids content of 70% in butyl acetate. - Synocure® 9201 S 75 Resin: High solids hydroxylated acrylic resin having an Iqh of 4.2% relative to resin mass with a medium viscosity (3000-4000 mPa.s at 25°C) and a solids content of 75% in a mixture of solvents (butyl acetate / ethyl 3-ethoxy propionate). - LP 1164 Resin: aliphatic polyester polyol resin having an I0H of 4.5% relative to the resin mass with a high viscosity (7500-12500 mPa.s at 25°C) and a dry extract of 70% in Solvesso™ 100. - Synocure® E21091 Resin: High solids hydroxylated acrylic resin having an IOH of 4.1% relative to resin mass with a medium viscosity (4000-7500 mPa.s at 25°C) and a solids content of 75% in butyl acetate.

[0082] Formulations made with Synocure 862X60 resin: Varnish Compositions F (comparative) GH Synocure® 862 X 60 74.89 70.12 86.44 Polyol catalyst of example 1 - 2.83 - Polyol catalyst of example 2 - - 3.10 Butyl acetate (AB) 15.17 18.79 0 Dibutyltin dilaurate (DBTDL) (1% in AB) 2.30 - - Tolonate™ HDT-LV2* 7.64 8.26 10.46 Total weight of formulation (g) 100.00 100.00 100.00 Volume extract (%) 46.5 46.5 59.6 High shear viscosity of formulation (mPa.s) (measured using a CAP 1000 vise-viscometer, (with a #3 mobile, at 25°C) 708 605 Very viscous Pot life or "Pot 1 ife" 2h35 15h50 - Dry thickness on QD46 (pm) 38 40 54 Persoz hardness at 1 day 154 152 132 Persoz hardness at 7 days 268 279 - Persoz hardness at 14 days 290 296 - Dry thickness on QD46 (pm) 38 40 54 Adhesion test after 1 / 7 / 14 days on QD46 0 / 0 / 0 0 / 0 / 0 0 / 0 / 0 Dry thickness on QD46 (pm) 30 38 55 Chemical resistance after 7 days (s) 55 111 120 Dry thickness on QD46 (pm) 31 41 48 Dust-free drying < 24 min 36 min 35 min * Tolonate™ HDT-LV2: solvent-free, low-viscosity hexamethylene diisocyanate trimer with an NCO content of 23%, marketed by Vencorex.

[0083] The addition of polyol catalysts according to the invention to the commercial Synocure® 862 X 60 resin confers the following properties to the two-component polyurethane system (compared to the reference composition comprising a dibutyltin dilaurate (DBTDL)-based catalyst): - Increased pot life, allowing for a greater window of time to apply the varnish, - Dust-free drying very close to the reference without polyol catalyst, - the polyol catalyst in example 1 provides a similar, or even slightly higher, Persoz hardness development than the reference without polyol catalyst. The polyol catalyst in example 2, having a thicker coating in this test, leads to a lower Persoz hardness development. - improved chemical resistance to MEK of systems with polyol catalysts according to the invention, even if the thicknesses differ, - very good adhesion.

[0084] Formulations made with Synocure® 9293 BA 70 resin: Varnish Compositions I (Comparative) JK Synocure® 9293 BA 70 75.81 71.56 71.33 Polyol Catalyst of Example 1 - 3.32 - Polyol Catalyst of Example 2 - - 2.91 Butyl Acetate (AB) 5.11 8.30 8.76 Dibutyltin Dilaurate (DBT DL) (1% in AB) 2.64 - - Tolonate™ HDT-LV2* 16.44 16.81 17.00 Total Formulation Weight (g) 100.00 100.00 100.00 Volume Extract (%) 65.0 65.0 65.0 High Shear Viscosity of Formulation (mPa.s) (measured using a CAP viscometer) 1000, with a mobile #3, at 25°C) 647 615 542 Pot life or "Pot 1 ife" 2h40 14h 6hl0 Dry thickness on QD46 (pm) 50 49 51 Persoz hardness at 1 day 113 116 193 Persoz hardness at 7 days 294 313 255 Persoz hardness at 14 days 312 323 271 Dry thickness on QD46 (pm) 50 49 51 Adhesion test after 1 / 7 / 14 days on QD46 0 / 0 / 0-1 0 / 0 / 0 0 / 0 / 0 Dry thickness on QD46 (pm) 40 51 52 Chemical resistance after 7 days: 84, 115, 90. Dry thickness on QD46 (pm): 41, 50, 54. Dust-free drying: 35 min, 56 min, 48 min. * Tolonate™ HDT-LV2: solvent-free, low-viscosity hexamethylene diisocyanate trimer with an NCO content of 23%, marketed by Vencorex.

[0085] The addition of polyol catalysts according to the invention to the commercial resin Synocure® 9293 BA 70 confers the following properties to the two-component polyurethane system (compared to the reference composition comprising a catalyst based on dibutyltin dilaurate (DBTDL)): - Increased pot life, allowing for a greater window of time to apply the varnish, - Dust-free drying very close to the reference level without polyol catalyst - The polyol catalyst in Example 1 provides a Persoz hardness development similar to, or even slightly greater than, the reference without a polyol catalyst. The polyol catalyst in Example 2 provides an initial Persoz hardness development significantly greater than the reference, and a more moderate Persoz hardness development over time. - improved chemical resistance to MEK of systems with polyol catalysts according to the invention, - very good adhesion.

[0086] Formulations made with Synocure® 9201 S 75 resin: L-Varnish Compositions (Comparative) NM Synocure® 9201 S 75 64.49 61.19 60.97 Example 1 Polyol Catalyst 3.03 - Example 2 Polyol Catalyst - - 2.68 Butyl Acetate (AB) 11.23 13.85 14.26 Dibutyltin Dilaurate (DBT DL) (1% in AB) 2.42 - - Tolonate™ HDT-LV2* 21.86 21.93 22.09 Total Formulation Weight (g) 100.00 100.00 100.00 Volume Extract (%) 65.0 65.0 65.0 High Shear Viscosity of Formulation (mPa.s) (measured using a CAP viscometer) 1000, with a mobile #3, at 25°C) 389 355 359 Pot life or "Pot 1 ife" IhlO 9h 4h40 Dry thickness on QD46 (pm) 50 49 50 Persoz hardness at 1 day 152 65 222 Persoz hardness at 7 days 315 337 294 Persoz hardness at 14 days 320 347 303 Dry thickness on QD46 (pm) 50 49 50 Adhesion test after 1 / 7 / 14 days on QD46 0 / 0 / 0 0 / 0 / 0 0 / 0 / 0 Dry thickness on QD46 (pm) 48 48 50 Chemical resistance after 7 days: 90, 100, 85. Dry thickness on QD46 (pm): 48, 47, 51. Dust-free drying: 2h40 - 3hl0 * Tolonate™ HDT-LV2: solvent-free, low-viscosity hexamethylene diisocyanate trimer with an NCO content of 23%, marketed by Vencorex.

[0087] The addition of polyol catalysts according to the invention to the commercial resin Synocure® 9201 S 75 confers the following properties to the two-component polyurethane system (compared to the reference composition comprising a catalyst based on dibutyltin dilaurate (DBTDL)): - Increased pot life, allowing for a greater window of time to apply the varnish, - Dust-free drying of the varnish containing the polyol catalyst from example 2, very close to the reference without the polyol catalyst. - The polyol catalyst in Example 1 provides a similar, or even slightly better, Persoz hardness development than the reference without a polyol catalyst. The polyol catalyst in Example 2 provides a significantly better initial Persoz hardness development than the reference, with good Persoz hardness development over time. - improved chemical resistance to MEK of systems with polyol catalysts according to the invention, - very good adhesion.

[0088] Formulations made with LP1164 resin: Varnish Composition A (comp.) B (comp.) CDE LP1164 66.15 66.15 64.01 62.58 60.46 Polyol Catalyst of Exemple 3 - - 1.58 2.64 4.21 Butyl Acetate (AB) 10.72 9.29 11.20 11.51 11.98 Dibutyltin Dilaurate (DBTDL) (1% in AB) 1.43 Tolonate™ HDT-LV2* 23.13 23.13 23.21 23.27 23.35 Total Formulation Weight (g) 100.00 100.00 100.00 100.00 100.00 Volume Extract (%) 65.0 65.0 65.0 65.0 65.0 High shear viscosity of formulation (mPa.s) (measured using a CAP 1000 oscillometer, with a #3 spindle, at 25°C) 622 854 870 819 724 Pot life or "Pot 1 ife" 41 min 34 min 115 56 min 51 min Dry thickness on QD46 (pm) 40 45 38 60 43 65 Persoz hardness at 1 day 50 44 110 58 111 24 Persoz hardness at 7 days 176 118 - 153 158 31 Persoz hardness at 14 days - - 191 - 28 Dry thickness on QD46 (pm) 274 170 - - 171 - Persoz hardness at 1 day 281 168 295 202 165 29 Dry thickness on QD46 (pm) 40 45 38 60 43 65 Adhesion test after 1 / 7 / 14 days on QD46 5 4-5 3-3 1-1 4-4 0-0 . Dry thickness on QD46 (pm) 40 45 38 60 43 65 Chemical resistance after 7 days (s) 60 60 60 140 55 60 Dry thickness on QD46 (pm) 40 45 - 60 43 60 Dust-free drying approximately 5 h approximately 3 h approximately 3 h 6.5 to 7.5 h approximately 3 h <3.5 h * Tolonate™ HDT-LV2: solvent-free, low-viscosity hexamethylene diisocyanate trimer with an NCO content of 23%, marketed by Vencorex.

[0089] The addition of polyol catalysts according to the invention to the commercial resin LP 1164 confers the following properties to the two-component polyurethane system (compared to the varnish composition B, reference comprising a catalyst based on dibutyltin dilaurate (DBTDL)): - Increased pot life, allowing for a greater window of time to apply the varnish, - Dust-free drying very close to the reference level without polyol catalyst - The polyol catalyst of Example 1 in varnish compositions C and D, at constant thickness, provides a significantly higher initial Persoz hardness development than the reference, with good Persoz hardness development over time; - the MEK chemical resistance of the systems with polyol catalyst according to the invention is similar to the reference without polyol catalyst. - improved adhesion, at constant thickness. A small amount of polyol catalyst according to the invention is sufficient to obtain better adhesion.

[0090] Evaluation of accelerated UV aging: The polyol catalyst in Example 2 was tested under UVB aging conditions with Synocure® E21091 resin in the following two-component polyurethane systems: - Cromax® 840R epoxy primer / Varnish: the polyol catalyst in example 2 was tested at two different resin / catalyst ratios: 97 / 3 and 95 / 5 (Cromax / Varnish 97 / 3 and Cromax / Varnish 95 / 5), - Direct To Metal (DTM) / Varnish: the polyol catalyst in example 2 was tested at a resin / catalyst ratio of 95 / 5 (DTM 95 / 5 varnish), - Direct To Metal (DTM) / Paint: the polyol catalyst in example 2 was tested at a resin / catalyst ratio of 97 / 3 (DTM Paint 97 / 3).

[0091] The behavior of these two-component polyurethane systems was compared to the Synocure® E21091 resin comprising dibutyl tin dilaurate (DBTDL) as a catalyst at 0.05% by weight relative to the weight of the dry resin (reference) (Cromax / DBTDL Varnish and DTM DBTDL Paint).

[0092] Formulations made with Synocure® E21091 resin: Varnish and Paint Compositions O (comp.) PQR (comp.) S Synocure® E21091 64.02 60.51 61.62 40.67 39.32 Example Polyol Catalyst 2 0 2.70 1.62 0 1.03 Butyl Acetate (AB) 12.06 15.07 15.23 3.85 5.61 Disperbyk® 163 0 0 0 1.27 1.27 Kronos® 2360 0 0 0 31.81 31.83 Tolonate™ HDT-LV2* 21.48 21.73 21.53 13.65 13.74 Dibutyltin Dilaurate (DBTDL) (1% in AB) 2.44 0 0 1.55 0 Butyl acetate (BA) 0 0 0 7.20 7.20 Total weight of formulation (g) 100.00 100.01 100.00 100.00 100.00 Pigment Volume Concentration (CVP) (%) 0 0 0 17 17 Volume extract (%) 65 65 64.6 65 65 High shear viscosity of formulation (mPa.s) (measured using a CAP 1000 viscometer, with a #3 mobile, at 25°C) 440 380 385 3070 2660 * Tolonate™ HDT-LV2: solvent-free, low-viscosity hexamethylene diisocyanate trimer with an NCO content of 23%, marketed by Vencorex.

[0093] Gloss measurements at 20° and color (AE* ab) over time were performed. The results are shown in Figures 1 and 2.

[0094] After 1500 hours of exposure to UVB, the following observations were made for the brightness measurements at 20° over time ([Fig.1]): - In a Cromax® 840R epoxy primer / clear coat system: Synocure® E21091 resin with the invention's polyol catalyst exhibits better (longer) gloss retention than Synocure® E21091 resin with DBTDL. In particular, the gloss of Synocure® E21091 resin with the invention's polyol catalyst maintains very good gloss retention up to approximately 1000 hours of UVB exposure, whereas the gloss of Synocure® E21091 resin with DBTDL drops after 800 hours of exposure. - In DTM / Paint system: Synocure® E21091 resin with the polyol catalyst of the invention shows better gloss retention than Synocure® E21091 resin with DBTDL. - In DTM / Varnish system: gloss retention is intermediate and follows the evolution of Synocure® E21091 resin with the polyol catalyst of the invention in DTM / Paint system.

[0095] After 1500 hours of UVB exposure, the following observations were made for the color measurements (AE* ab) over time ([Fig.2]): - In the Cromax® 840R epoxy primer / varnish system: the Synocure® E21091 resin with the polyol catalyst of the invention at a ratio of 97 / 3 is very close to the Synocure® E21091 resin with DBTDL. The Synocure® E21091 resin with the polyol catalyst of the invention at a ratio of 95 / 5 is slightly more colored. - In DTM / Painting systems: Synocure® E21091 resin with the polyol catalyst of the invention has a color very close to that of Synocure® E21091 resin with DBTDL. The AE* ab values ​​are close to 1 and remain stable. No noticeable difference is observed to the naked eye. - In DTM / Varnish system: the AE* ab is intermediate, around 13.

Claims

Demands

1. Polyol catalyst comprising: - at least two alcohol functions, and preferably two alcohol functions, - at least one catalyst function selected from imidazole and / or tertiary amine functions, and preferably at least two catalyst functions selected from imidazole and / or tertiary amine functions, - at least one urea function, and preferably at least two urea functions.

2. Catalyst according to claim 1, characterized in that the tertiary amine function has a pKa > 9, preferably a pKa > 10.

3. Catalyst according to claim 1 or claim 2, characterized in that the tertiary amine function corresponds to the formula -NRiR2 in which Ri and R2, identical or different, represent a C1-C4 alkyl or a cycloalkyl or Ri and R2 form a C2-C6 heterocycle.

4. Catalyst according to claim 1, characterized in that the imidazole function corresponds to the following formula: J' in which R3, R4 and R5 are independently chosen from H, alkyl, aryl and alkylaryl or R4 and R5, together with the carbon atoms to which they are bonded, can form a ring.

5. Catalyst according to any one of claims 1 to 4, characterized in that the urea function is a substituted urea function, preferably a substituted urea function corresponding to the formula *-NR6-C(=0)-NH-* in which R6 is other than H, in particular R6 is derived from a Michael reaction between a primary amine and a compound functionalized by at least one (meth)acrylate group.

6. Catalyst according to any one of claims 1 to 5, characterized in that the urea function corresponds to the formula Z-NR6-C(=O)-NH-* in which: R6 comprises a motif of formula #-CH2-CH2-C(=O)-O-§ Z is -A'-(CAT)P in which: A' is an alkylene or an alkylene comprising at least one heteroatom, preferably a C2-C6 alkylene, p is 1 or 2, and preferably 1, CAT is a catalyst function selected from the imidazole and / or tertiary amine functions, as defined according to any one of claims 1 to 4; the symbol * represents an attachment point to a carbon atom, the symbol # represents an attachment point to the nitrogen atom of the substituted urea function, and the symbol § represents an attachment point to a carbon atom.

7. Catalyst according to any one of claims 1 to 6, characterized in that it corresponds to the following formula (1): | 0 p mH-C- M—ÇH^CHr-C—0— A-OH I 2 -■ -b (1) in which: -1 is the residue of a polyisocyanate, and preferably the residue of a diisocyanate, - Z is a group comprising at least one catalyst function as defined according to any one of claims 1 to 4, - A is the residue of a polyol, and preferably a C2-C12 alkylene optionally alkoxylated or esterified, - a = 1 to 5, and preferably a = 1, and - b = 2 to 3, and preferably b = 2.

8. A process for preparing a catalyst according to any one of claims 1 to 7, characterized in that it comprises the steps: (i) Michael reaction between a hydroxylated (meth)acrylate monomer and a monomer having at least one primary amine function and at least one catalyst function selected from the imidazole and / or tertiary amine functions, and (ii) reaction between the amino-ester compound obtained at the end of step (i) with a polyisocyanate.

9. A process according to claim 8, characterized in that the hydroxylated (meth)acrylate monomer used in step (i) is selected from 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3-chloro-2-hydroxypropyl acrylate, glycerin monoacrylate, trimethylolpropane monoacrylate, di(trimethylolpropane) monoacrylate, trimethylolethane monoacrylate, pentaerythritol monoacrylate, dipentaerythritol monoacrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, polyethylene-co-polypropylene glycol acrylate, polytetramethylene glycol monoacrylate,a polycaprolactone (meth)acrylate corresponding to the following formula (2): s 9 tW' V' O| fH a "n (2) in which R represents H or methyl, and n = 1 to 10, or mixtures thereof.,

10. A process according to claim 8 or claim 9, characterized in that the monomer having at least one primary amine function and at least one catalyst function selected from the imidazole and / or tertiary amine functions implemented in step (i) is selected from N,N-dimethylethylenediamine, N,N-diethylethylenediamine, dimethylaminopropylamine (DMAPA), 3-(diethylamino)-l-propylamine (DEAPA), 4-(dimethylamino)-l-butylamine, 4-(diethylamino)-l-butylamine, 5-(dimethylamino)-l-pentylamine, N,N-dimethyldipropylenetriamine (DMAPAPA), 2-morpholinoethylamine, 3-morpholinopropylamine, 2-piperidinoethylamine, 3-piperidinopropylamine, 5-piperidinopentylamine, 2-(4-methyl-l-piperidinyl)ethanamine, 2-pyrrolidinoethylamine, 3-pyrrolidinopropylamine, 2-(2-aminoethyl)-l-methylpyrrolidine, 2-(4-methyl-piperazin-l-yl)-ethylamine, l-(3-aminopropyl)imidazole, l-(3-aminopropyl)-2-methyl-lH-imidazole, l-(4-aminobutyl)imidazole, or mixtures thereof.

11. A process according to any one of claims 8 to 10, characterized in that the polyisocyanate used in step (ii) is selected from isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane 4,4'-diisocyanate (4,4'-MDI), dicyclohexylmethane 4,4'-diisocyanate, tetramethylxylene diisocyanate (TMXDI), hydrogenated tetramethylxylene diisocyanate, hexamethylene diisocyanate (HDI), norborane diisocyanate (NBDI), trimethylenehexamethylene diisocyanate, 1,5-naphthylene diisocyanate, biuret, allophonate and isocyanurate forms of these polyisocyanates, or mixtures thereof.

12. Use of a polyol catalyst according to any one of claims 1 to 7, as a catalyst in a two-component crosslinkable polyurethane composition comprising a polyisocyanate component and a polyol component other than the polyol catalyst.

13. Use of a polyol catalyst according to any one of claims 1 to 7, as a polyol component in a two-component crosslinkable polyurethane composition further comprising a polyisocyanate component and optionally another polyol component free of catalyst function selected from imidazole and / or tertiary amine functions.

14. Two-component crosslinkable polyurethane composition characterized in that it comprises: a) a polyisocyanate component, b) a polyol component comprising: b1) from 0.1 to 100% by weight, relative to the total weight of the polyol component, of a polyol catalyst according to any one of claims 1 to 7, and b2) from 0 to 99.9% by weight, relative to the total weight of the polyol component, of another polyol component free of catalyst function selected from imidazole and / or tertiary amine functions.

15. Composition according to claim 14, wherein the polyol component comprises: b1) 0.1 to 10% by weight, and preferably between 1 and 7% by weight, relative to the total weight of the polyol component, of a polyol catalyst according to any one of claims 1 to 7, and b2) 90 to 99.9% by weight, and preferably between 93 and 99% by weight, relative to the total weight of the polyol component, of another polyol component free of a catalyst function selected from the imidazole and / or tertiary amine functions.

16. Composition according to claim 14, wherein the polyol component comprises: b1) from 10 to 100% by weight, relative to the total weight of the polyol component, of a polyol catalyst according to any one of claims 1 to 7, and b2) from 0 to 90% by weight, relative to the total weight of the polyol component, of another polyol component free of catalyst function selected from the imidazole and / or tertiary amine functions.

17. Composition according to any one of claims 14 to 16 characterized in that it is free from tin-based catalyst.

18. Composition according to any one of claims 14 to 17 characterized in that it is a coating composition, and more particularly an aqueous coating composition, preferably selected from paint, varnish, ink, adhesive or glue compositions, and more preferably a paint or varnish composition.

19. A method for preparing a coating characterized in that it comprises a step of applying a two-component crosslinkable polyurethane composition according to any one of claims 14 to 18 onto a substrate, followed by a step of drying said composition, preferably at room temperature (20°C).

20. Substrate coated with a two-component crosslinkable polyurethane composition according to any one of claims 14 to 18, characterized in that it is selected from substrates of metal, glass, wood, including chipboard and plywood, plastic, metal, concrete, plaster, composite, textile.

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