POLYASPARTIC COMPOSITIONS

Abstract

The invention relates to compositions for coating preparations comprising at least one polyaspartic ester compound, at least one isocyanate compound and optionally at least one additive.

Claims

1. A composition for preparing coatings comprising: at least one polyaspartic ester compound (a), a mixture of isocyanate compounds (b), having an NCO content of more than 13% and the viscosity of which is less than 1500 mPa's at 25? C., comprising: at least one allophanate (b1) and at least one polyfunctional isocyanate (b2), wherein the mass ratio (b1)/(b2) is between 50/50 and 99/1, wherein the molar ratio (b)/(a) defined by the number of NCO functions for (b) and the number of NH functions for (a) is between 0.7 and 1.3, optionally at least one additive (c).

2. The composition according to claim 1, wherein the polyaspartic ester (a) is a polyaspartic ester according to general formula (I): wherein X represents an aliphatic chain or a polyether chain, R.sub.1 and R.sub.2 are, independently of each other, an organic group that is inert with respect to an isocyanate group at normal atmospheric pressure and at 100? C. or less, n represents an integer greater than or equal to 2.

3. The composition according to claim 2, wherein the aliphatic residue X consists of one or more of the following residues chosen from a polyether residue, a linear alkyl residue, a branched alkyl residue and a cycloalkyl residue.

4. The composition according to claim 2, wherein the polyaspartic ester(s) (a) of general formula (I) are one or more polyaspartic ester(s) or a mixture of polyaspartic esters: of general formula (II) and/or ##STR00011## of general formula (III) and/or ##STR00012## of general formula (IV) and/or ##STR00013## of general formula (V) ##STR00014## wherein the groups R.sub.1 and R.sub.2 are, independently of each other, a C.sub.1-C.sub.10 alkyl group and u is an integer between 1 and 10.

5. The composition according to claim 4, wherein the groups R.sub.1 and R.sub.2 are, independently of each other, one or more methyl, ethyl or butyl groups.

6. The composition according to claim 1, wherein the polyaspartic ester (a) is chosen from tetraethyl N,N-(methylenedicyclohexane-4,1-diyl)bis-DL-aspartate, N,N-(tetraethyl methylenebis(2-methyl-cyclohexane-4,1-diyl)bis-DL-aspartate or tetraethyl N,N-(2-methylpentane)bis-DL-aspartate.

7. The composition according to claim 1, wherein the allophanate (b1) has an NCO functionality equal to 2.1+0.3 and of general formula (VI): wherein R.sub.3 and R.sub.4, which may be identical or different, represent a hydrocarbon group comprising at least one function selected from an isocyanate, carbamate, urea, biuret uretinedione, acylurea, isocyanurate, blocked isocyanate or allophanate function, R.sub.5 represents the residue of a molecule comprising an OH function after reaction of this OH function with an isocyanate function and the molecule of which containing an OH group can also comprise an ether or polyether function and chosen from a silanol, a C.sub.12-C.sub.20 linear aliphatic monoalcohol, a C.sub.12-C.sub.20 branched aliphatic monoalcohol, a C.sub.2-C.sub.40 linear diol or a C.sub.3-C.sub.40 branched diol of which at least one of the hydroxyl groups is substituted and which has general formula (VII): ##STR00015## wherein T.sub.1 represents a C.sub.1-C.sub.20 linear alkyl group, a C.sub.1-C.sub.20 branched alkyl group, a group of formula T.sub.3COCH.sub.3 wherein T.sub.3 represents a C.sub.1-C.sub.20 linear alkyl group or a C.sub.1-C.sub.20 linear alkyl group; T.sub.2 represents hydrogen or an alkyl group or an ether group of formula CH.sub.2OT.sub.4 wherein T.sub.4 represents a hydrocarbon chain and m represents an integer ranging from 1 to 50.

8. The composition according to claim 7, wherein R.sup.3 and R.sub.4, which may be identical or different, represent an aliphatic hydrocarbon group comprising at least one function chosen from an isocyanate, carbamate, urea, biuret uretinedione, acylurea, isocyanurate, blocked isocyanate or allophanate function.

9. The composition according to claim 1, wherein the compound (b2) is at least one polyfunctional isocyanate of general formula (VIII): ##STR00016## wherein R.sub.6, R.sub.7 and R.sub.8 independently represent a hydrocarbon group or an aliphatic, cycloaliphatic, heterocyclic or aromatic heterocarbon group, comprising at least one function chosen from an isocyanate, carbamate, urea, biuret uretinedione, acylurea, isocyanurate, blocked isocyanate or allophanate function, p represents an integer chosen from 0, 1 or 2, Y represents a group chosen from an isocyanurate group of formula (Y.sub.1), an imino oxadiazine dione group of formula (Y.sub.2), an oxadiazine trione group of formula (Y.sub.3), a biuret group of formula (Y.sub.4) or a group of formula (Y.sub.5): ##STR00017## wherein R.sub.9 represents, independently, a hydrogen atom, a hydrocarbon group, a C.sub.1-C.sub.20 hydrocarbon group, a heterocarbon group comprising at least one heteroatom chosen from O, N, S and Si, a C.sub.1-C.sub.20 heterocarbon group comprising at least one heteroatom chosen from O, N, S and Si, q represents an integer chosen from 3 or 4, R.sub.10 represents a group chosen from a hydrocarbon group, an alkyl group, a heterocarbon group, an aliphatic, cycloaliphatic, heterocyclic or aromatic heterocarbon group, comprising a function chosen from an isocyanate, carbamate, urea, biuret, uretinedione, acylurea, isocyanurate, blocked isocyanate or allophanate function, a group derived from pentaerythritol, a group derived from trimethylolpropane.

10. The composition according to claim 9, wherein the Y group is an isocyanurate (Y.sub.1) and/or biuret group (Y.sub.4).

11. The composition according to claim 10, wherein the polyfunctional isocyanate (b2) is a group comprising at least one isocyanurate and/or a biuret wherein the groups are obtained from the oligomerisation of the following compounds: hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), bis(4,4-isocyanatocyclohexyl)methane, 1,4-cyclohexylene diisocyanate, 1,3-bis(isocyanatomethyl)benzene (XDI), 1,3-bis(2-isocyanatoprop-2-yl)-benzene, 1,4-bis(2-isocyanatoprop-2-yl)-benzene (TMXDI), norbornane diisocyanate (NBDI), hydro-xylylene diisocyanate (H.sub.6XDI), 1,4-cyclohexyl diisocyanate (H.sub.6PPDI), 1,5-pentane diisocyanate (PDI) and/or dicyclohexylmethane diisocyanate.

12. The composition according to claim 1, wherein the additive (c) is chosen from: a wetting agent, a dispersant, a matting agent, an anti-foaming agent, a thickener, a molecular sieve, an elastomer, a pigment, a surfacing agent and a coalescing agent.

13. A method for preparing the composition according to claim 1, comprising the following steps: 1. preparing at least one polyaspartic ester (a), 2. preparing at least one isocyanate compound (b1) and at least one isocyanate compound (b2), 3. optionally preparing at least one additive (c), 4. mixing the preparations obtained in steps 1 and 2 and optionally 3.

14. A use of a composition according to anyone of claim 1 as an adhesive coating or as a protective coating of a substrate or a coated substrate.

15. An adhesive coating or a protective coating of a substrate or coated substrate comprising a composition according to any of claim 1.

16. The coating according to claim 15, wherein the substrate or the coated substrate is a floor, a roof, a waterproofing membrane, a wind turbine mast, an aircraft wing, a rotor blade, a propeller blade or a turbine blade.

Description

EXAMPLES

Materials:

[0107] The product Feiyang F420 is a polyaspartic acid ester resin consisting of aliphatic rings substituted with secondary amines. This resin is similar to the Desmophen NH-1420 and Teraspartic 277 resins. Characteristics of Feiyang F420: [0108] Equivalent amine (g/mol): 277 [0109] Dynamic viscosity at 25? C.: 1000-1500 mPas [0110] Density: 1.06

[0111] The product Feiyang F520 is a polyaspartic acid ester resin consisting of aliphatic rings substituted with secondary amines. This resin is similar to the Desmophen NH-1520 and Teraspartic 292 resins. Characteristics of Feiyang F520: [0112] Equivalent amine (g/mol): 290 [0113] Dynamic viscosity at 25? C.: 1200-1500 mPa.Math.s [0114] Density: 1.06

[0115] Tolonate HDT is an isocyanurate-type polyisocyanate prepared from hexamethylenediisocyanate.

[0116] Characteristics of Tolonate HDT: [0117] NCO functionality: 21.5-22.5%, [0118] Dynamic viscosity (at 25? C.): 2000-2800 mPa.Math.s, [0119] Density (at 25? C.): 1.16

[0120] Tolonate HDT-LV is an isocyanurate-type polyisocyanate prepared from hexamethylenediisocyanate.

[0121] Characteristics of Tolonate HDT-LV: [0122] NCO functionality: 22-24%, [0123] Dynamic viscosity (at 25? C.): 900-1500 mPa.Math.s, [0124] Density (at 25? C.): 1.16

[0125] Tolonate HDB is a biuret-type polyisocyanate prepared from hexamethylenediisocyanate. Characteristics of Tolonate HDB: [0126] NCO functionality: 21-23%, [0127] Dynamic viscosity (at 25? C.): 7000-11000 mPa.Math.s, [0128] Density (at 25? C.): 1.12

[0129] Tolonate HDB-LV is a biuret-type polyisocyanate prepared from hexamethylenediisocyanate. Characteristics of Tolonate HDB-LV: [0130] NCO functionality: 22.5-24.5%, [0131] Dynamic viscosity (at 25? C.): 1500-2500 mPa.Math.s, [0132] Density (at 25? C.): 1.12

[0133] HDT Dimer is an isocyanurate-type polyisocyanate prepared from hexamethylenediisocyanate. [0134] NCO functionality: 22-24%, [0135] Dynamic viscosity (at 25? C.): 450-750 mPa.Math.s, [0136] Density (at 25? C.): 1.13

[0137] Tolonate X-FLO 100 is an allophanate-type polyisocyanate prepared from hexamethylenediisocyanate.

[0138] Characteristics of Tolonate X-FLO 100: [0139] NCO functionality: 11.3-13.3%, [0140] Dynamic viscosity (at 25? C.): 60-220 mPa.Math.s, [0141] Density (at 25? C.): 1.04

[0142] Silosiv A3 is an additive useful as a molecular sieve.

[0143] Tego Airex 944 is an additive useful as an anti-foaming agent.

[0144] BYK 378 is an additive useful as a surfactant.

[0145] All the additives, polyisocyanates and resins used in the examples are commercially available products.

Example 1: Preparation of compositions (A)

[0146] In order to prepare the compositions (A), the different products are weighed according to the proportions indicated in Table 1, then mixed using a Speedmixer until the mixture is homogenised.

[0147] Table 1 describes the proportions of each polyaspartic resin and additive according to each composition A.

TABLE-US-00001 TABLE 1 A1 A2 Compositions (A) (% by mass) (% by mass) Feiyang F420 95.6 66.9 Feiyang F520 0 28.7 Silosiv A3 1.9 1.9 Tego Airex 944 1.8 1.8 BYK 378 0.7 0.7

Example 2: Preparation of polyisocyanate compositions (B)

[0148] In order to produce the compositions (B), the mixtures are prepared according to the proportions described in Table 2. The polyisocyanate mixtures (B) are then homogenised for at least one night in a mixing unit.

[0149] The NCO content is measured by titration of the NCO functions of each compound using a back titration of dibutylamine with a hydrochloric acid solution.

[0150] The viscosity is measured at 25? C. using an Anto-Paar viscometer with cone-plane geometry having an angle of 2?. The shear rate during measurement ranges from 0.1 to 100 s-1 with a rise and fall in the shear rate.

[0151] Low viscosity is defined by a viscosity less than 1500 mPa.Math.s and a sufficient NCO content is defined by a value greater than 13%.

[0152] Table 2 presents the proportions of polyisocyanates, the viscosity and the NCO content according to each composition B.

TABLE-US-00002 TABLE 2 HDT- HDB- HDT- X Flo Viscosity NCO Compositions HDT LV HDB LV Dimer 100 at 25? C. content (B) (%) (%) (%) (%) (%) (%) (mPa .Math. s) (%) B1 15 85 170 13.8 B14 25 75 233 14.7 B2 40 60 365 16.2 B3 (comp.) 100 0 2400 22.0 B4 15 85 234 13.9 B15 25 75 211 15 B5 40 60 323 16.6 B6 (comp.) 100 0 1200 23.0 B7 15 85 190 13.8 B8 25 75 260 14.7 B9 40 60 460 16.2 B10 (comp.) 100 0 9000 22.0 B11 15 85 221 13.9 B16 25 75 254 15.1 B12 40 60 393 16.6 B13 (comp.) 100 0 2000 23.0 B17 15 85 164 13.9 B18 25 75 179 15.0 B19 40 60 228 16.6 B20 (comp.) 100 0 600 23.0

[0153] As specified in Table 2, the compositions B3, B6, B10, B13 and B20 comprise 100% of each isocyanate. These are comparative examples (comp.).

[0154] The results show a decrease in viscosity with increasing amounts of Tolonate X-FLO 100 in the composition (B) used. The use of a proportion of Tolonate X-FLO 100 greater than or equal to 60% makes it possible to obtain compositions (B) with a viscosity of less than 1500 mPa.Math.s at 25? C. and with an NCO content of more than 13%.

[0155] The comparative examples, although having an NCO content of more than 13%, have a viscosity greater than 1500 mPa.Math.s, except for example B6.

Example 3: Elongation of the compositions

[0156] Elongation is measured on coatings resulting from the mixture between the compositions (A) and the polyisocyanates (B) described in examples 1 and 2. This mixture is carried out using a Speedmixer to ensure good homogeneity, the formulations thus obtained are then crosslinked for 7 days in an enclosure regulated at 23? C. and 50% humidity. The mixing ratio between the compositions (A) and (B) is defined by an NCO/NH ratio that is equimolar, i.e., constant and equal to 1. The NH functionalities are present in the compositions (A) and the NCO functionalities are present in the polyisocyanates (B).

[0157] The elongation measurements are carried out using a traction machine (MTS) on specimens of standardised format (type 5A specimen of standard ISO 527-2) with a thickness between 1 and 2 mm. The traction speed is set at 10 mm/min.

[0158] The elongation at break corresponds to the elongation value reached when the specimen breaks. The sample is considered to have improved flexibility properties with an elongation at break of more than 50%.

[0159] Table 3 presents the elongation at break results for the different compositions A and B.

TABLE-US-00003 TABLE 3 Compositions Compositions (A) (B) Elongation (%) A1 B1 145 B2 110 B3 (comp.) <20 B4 389 B5 55 B6 (comp.) <20 B7 401 B8 230 B9 81 B10 (comp.) B11 470 B12 69 B13 (comp.) <20 B14 221 B15 237 B16 228 B17 108 B18 264 B19 543 B20 (comp.) <20 A2 B1 642 B2 219 B3 (comp.) <20 B4 777 B5 188 B6 (comp.) <20 B7 600 B8 405 B9 230 B10 (comp.) B11 647 B12 162 B13 (comp.) <20 B14 484 B15 490 B16 450 B17 258 B18 532 B19 730 B20 (comp.) <20

[0160] As specified in Table 3, the compositions comprising the polyisocyanate mixtures B3, B6, B10, B13 and B20 are comparative examples (comp.). These comparative examples stand out for their low flexibility (elongation at break well below 50%). Example B6, despite having a low viscosity, did not make it possible to obtain sufficient elongation at break (>50%). The elongation measurements in the mixtures containing the composition B10 could not be carried out due to the viscosity of the mixture being too high to be properly applied.

[0161] The composition has improved flexibility from a proportion by mass of Tolonate X-FLO 100 in the composition (B) greater than or equal to 60%. The effect is all the more marked with the use of a mixture containing composition (A2).