HIGH FUNCTIONALITY AMINOACRYLATE-ACRYLATE URETHANES DERIVED FROM THE ADDITION OF A SECONDARY-AMINE AMINO ALCOHOL TO A MULTIFUNCTIONAL ACRYLATE

Abstract

An aminoacrylate-acrylate urethane comprises at least one urethane function bonded to an aminoacrylate group, this group having a plurality of acrylate groups and being derived from the reaction of a) a hydroxylated aminoacrylate bearing one or more acrylate groups with b) a polyisocyanate. The aminoacrylate a) is produced by the addition of a1) an amino alcohol bearing a hydroxyl group and a secondary amine group to a2) at least one multifunctional acrylate, with a2) being in stoichiometric excess relative to the secondary amine groups of said amino alcohol a1).

A method for preparing the urethane acrylate comprises preparing the aminoacrylate a) by a Michael addition reaction. The aminoacrylate-acrylate urethane may be used in curable compositions, more particularly as a synergist, and also to cured finished products from the urethane acrylate.

Claims

1. A urethane aminoacrylate-acrylate comprising at least two urethane functions bonded to an aminoacrylate group, the latter bearing one or more acrylate groups, and wherein the urethane aminoacrylate-acrylate is derived from the reaction of a) a hydroxylated aminoacrylate bearing one or more acrylate groups with b) a polyisocyanate, the hydroxyl groups being in excess relative to the isocyanate groups of the polyisocyanate b), with said aminoacrylate a) being produced by the addition of a1) an amino alcohol bearing a hydroxyl group and a secondary amine group and optionally bearing both a secondary and a tertiary amine group, to a2) at least one inultifunctional acrylate having an acrylate functionality or number-average acrylate functionality fa2 ranging from 2 to 6 per mole, with a2) being in stoichiometric excess of acrylate groups relative to the secondary amine groups NH of said amino alcohol a1), with a ratio r1 of groups r1=acrylate/NH>1, the ratio r2 of groups r2=OH/NCO>1 and up to 1.4, said urethane aminoacrylate-acrylate containing a content t.sub.Aa of aminoacrylate groups, expressed in milliequivalents per gram (mEq/g), of said urethane aminoacrylate-acrylate ranging from 0.3 to 6.0.

2. The urethane aminoacrylate-acrylate as claimed in claim 1, having a density d.sub.A of acrylate groups ranging from 0.4 to 12.0 mEq/g of said urethane aminoacrylate-acrylate.

3. The urethane aminoacrylate-acrylate as claimed in claim 1 having a number-average acrylate functionality f.sub.Acr ranging from 0.4 to 60 acrylates per mole of said urethane aminoacrylate-acrylate.

4. The urethane aminoacrylate-acrylate as claimed in claim 1, wherein ratio r1 of groups r1=acrylate/NH ranges from fa.sub.2/(fa.sub.2-1) to 2.fa.sub.2, when fa.sub.2 is at least three 3, with fa.sub.2 being the functionality or number-average functionality, if it is a mixture, of said acrylate a2) expressed in acrylate/mole of a2).

5. The urethane aminoacrylate-acrylate as claimed in claim 1, wherein said polyisocyanate b) has a functionality fb or number-average functionality ranging from 2 to 4.

6. The urethane aminoacrylate-acrylate as claimed in claim 5, wherein said polyisocyanate is selected from aliphatic, cycloaliphatic or aromatic polyisocyanates or biuret trimer or triisocyanurate derivatives thereof or said polyisocyanates that have been allophanate-modified.

7. The urethane aminoacrylate-acrylate as claimed in claim 1, wherein said amino alcohol a1) is selected from the amino alcohols defined by the general formula below: R.sub.1NHR.sub.2OH, with R.sub.1 being C.sub.1 to C.sub.4 alkyl and R.sub.2 being a C.sub.2 to C.sub.12 alkylene or a cycloalkylene or aralkylene.

8. The urethane aminoacrylate-acrylate as claimed in claim 7, wherein said amino alcohol is chosen from: N-methylethanolamine, N-isobutylethanolamine, N-ethylethanolamine, N-butylethanolamine and N-(2-hydroxyethyl)piperazine).

9. The urethane aminoacrylate-acrylate as claimed in claim 1, wherein said multifunctional acrylate a2) is a multifunctional acrylate monomer which is an acrylate ester of a C.sub.2 to C.sub.10 alkylene polyol, said alkylene optionally comprising an ether bond, or of a cycloaliphatic polyol, said polyols having a functionality ranging from 2 to 6.

10. The urethane aminoacrylate-acrylate as claimed in claim 1, wherein said multifunctional acrylate a2) is a mixture of at least two multifunctional acrylates and optionally said amino alcohol a1) is likewise a mixture of at least two amino alcohols.

11. The urethane aminoacrylate-acrylate as claimed in claim 1, having a viscosity at 60 C., measured by the Noury method according to standard AFNOR XP.T51-213, ranging from 1 to 20 Pa.Math.s.

12. A process for preparing a urethane aminoacrylate-acrylate as defined in claim 1, comprising the steps of: i) preparing said hydroxylated aminoacrylate a) by Michael addition reaction of said amino alcohol a1) to said multifunctional acrylate a2), the latter being in stoichiometric excess relative to the NH groups of said amino alcohol a1), with the ratio of groups r1 =acrylates/NH being>1, ii) reacting said aminoacrylate a) of step i) with said polyisocyanate b), with a ratio r2=OH/NCO ranging from 1.05 to 1.40, in order to obtain said urethane aminoacrylate-acrylate.

13. A curable composition of organic binder comprising, as binder, at least one urethane acrylate as defined in claim 1.

14. The composition as claimed in claim 13 further comprising at least one reactive diluent chosen from monofunctional or multifunctional (meth)acrylate monomers.

15. The composition as claimed in claim 14, wherein the composition is curable by radiation or by the peroxide route or by the mixed route or by Michael addition with a polyamine.

16. The composition as claimed in claim 14, wherein the composition is curable under radiation chosen from UV, LED, laser, and electron beam.

17. The composition as claimed in claim 14, wherein said composition is a coating composition, optionally an ink, varnish, paint or adhesive composition or a composition for 3D printing or for manufacturing 3D objects by laying down successive layers, a sealant composition, a chemical sealing composition, a concrete composition or a composite composition.

18.-21. (canceled)

22. A cured finished product obtained by the process as defined in claim 12.

23. The product as defined in claim 22, wherein the product is chosen from: a coating or from: a product obtained by 3D printing, a 3D product obtained by laying down successive layers, a seal or chemical sealing, or concrete or composite.

24. The urethane aminoacrylate-acrylate of claim 1, wherein said aminoacrylate group bears 2 acrylates groups.

25. The urethane aminoacrylate-acrylate of claim 1, wherein said aminoacrylate group bears 3 acrylates groups.

26. The urethane aminoacrylate-acrylate of claim , wherein said ratio r1 is at least 1.5.

27. The urethane aminoacrylate-acrylate of claim 1, wherein said ratio r2 is ranging from 1.05 to 1.4.

28. The urethane aminoacrylate-acrylate of claim 1, wherein said content t.sub.Aa is ranging from 0.4 to 5 mEq/g.

Description

EXAMPLES

[0068]

TABLE-US-00001 TABLE 1 starting materials used Function Trade name Abbreviated according to (REF) Chemical name name Supplier the invention Functionality Penta radcure Pentaerythritol PET Perstorp Polyol 4 DiTMP DiTrimethylolPropane DiTMP Perstorp Polyol 3 Glacial acrylic Acrylic acid AA Arkema Acrylic acid 1 acid Toluene Toluene Tol TOTAL Solvent MSA E-pur Methanesulfonic acid MSA Arkema Catalyst Para- Methyl Ether of MEHQ Rhodia Inhibitor methoxyphenol Hydroquinone flakes SR351 Trimethylolpropane TMPTiA Arkema acrylate a2) 3 TriAcrylate Sartomer SR295 Pentaerythritol PETTA Arkema acrylate a2) 4 TetraAcrylate Sartomer SR355 DiTriMethylolPropane DiTMPTA Arkema acrylate a2) 4 TetraAcrylate Sartomer N- N- NMEA BASF Amino 1 MethylEthanol MethylEthanolAmine alcohol a1) Amine IPDI Isophorone IPDI Vencorex Isocyanate b) 2 Diisocyanate TIB KAT216 DiOctylTin diLaurate DOTL TIB Catalyst TriPhenyl TriPhenyl Phosphite TPPte AKZO Stabilizer Phosphite Nobel Phenothiazine Thiodiphenylamine PTZ Clariant Stabilizer BHT BisTert-Butyl BHT Innochem Stabilizer HydroxyToluene Speedcure 2,4,6- TPO Lambson Photo- TPO-L trimethylbenzoylphenyl- Initiator phosphinic acid ethyl ester Speedcure 2,4- DETX Lambson Photo- DETX diethylthioxanthone Initiator Darocur 2-Hydroxy-2-Methyl- DC1173 BASF Photo- 1173 Phenyl-Propane-1-one Initiator

1) Preparation of the Reference Products (Prior Art)

[0069] Reference 1

[0070] Hydroxylated Acrylate HA-1

[0071] The following are introduced into a 1-liter reactor equipped with an anchor stirrer and on which is mounted a florentine tube with its condenser (device enabling continuous withdrawal of the esterification water under solvent reflux), with an air inlet (air sparge) and with a thermometer probe: 468.3 g of acrylic acid (AA) (6.50 mol), 221.1 g of pentaerythritol (PET) (1.63 mol), 300.0 g of toluene, 10.0 g of methanesulfonic acid in aqueous solution at 70% (MSA-aq) (0.07 mol) and 0.60 g of methyl ether of hydroquinone (MEHQ).

[0072] The reaction mixture is refluxed until the reaction medium has an acid number of 66 mg KOH/g (that is to say 8.5% of residual AA). This corresponds to approximately 10 hours of reflux, the reaction medium thus passing from a temperature of 100 C. (start of boiling) to 110 C. at the time of the interruption of the esterification carried out by cooling the reaction medium (after having distilled approximately 95 ml of water). 500.0 g of toluene are then added.

[0073] This organic phase is neutralized with stirring at 50 C. for 30 minutes with 260.0 g of an aqueous 20% sodium carbonate solution. The mixture is left to separate out for 2 hours and, after elimination of the aqueous phase (lower phase) 30 g of an aqueous 20% sodium carbonate solution are added to the organic phase (upper phase). The mixture is stirred for 30 minutes at 50 C., and then left to separate out for 2 hours. After the aqueous phase (lower phase) has been discarded, the organic phase has a residual AA content<0.1%. If the residual AA is greater than this value, the organic phase is again treated with 30 g of an aqueous 20% sodium carbonate solution with the same stirring and settling out times and temperature. 30 g of demineralized water are added to the organic phase (upper phase). The mixture is stirred for 30 minutes at 50 C., and then left to separate out for 2 hours. After the aqueous phase (lower phase) has been discarded, the organic phase has a pH<9 (pH paper). If the pH is greater than this value, the organic phase is again treated with 30 g of demineralized water with the same stirring and settling out times and temperature.

[0074] 1.0 g of methyl ether of hydroquinone (MEHQ) is added to the organic phase, which is then placed in a rotary evaporator. The organic phase is distilled under vacuum by bringing the temperature to 80 C., then 95 C. and by lowering the pressure gradually to 200 mbar, then 100 mbar until the toluene has been completely eliminated (stagnation of the distilled volume; % residual toluene<0.1%).

[0075] A hydroxylated polyacrylate product HA-1 having the following characteristics is obtained: [0076] Appearance: clear [0077] Viscosity at 25 C.: 900 mPa.Math.s [0078] OH number of the product: 120.0 mg KOH/g

[0079] Reference Urethane Acrylate Ref-U1

[0080] The following are introduced into a 1-liter reactor equipped with an anchor stirrer, with an air inlet (air sparge) and with a thermometer probe: 834.24 g of the hydroxylated acrylate HA-1 above (1.7845 OH equivalents), 2.0 g of BHT, 0.5 g of DOTL. Once the mixture has been brought to 60 C., 164.7 g of IPDI (1.4871 NCO equivalents) are introduced over the course of 1 hour while evenly increasing the temperature to 90 C. The mixture is maintained at this temperature by regularly controlling the isocyanate number (NNCO), until the value of the latter is less than 0.5 mg KOH/g. A reference urethane acrylate Ref-U1 having the following characteristics is obtained: [0081] Appearance: clear (visual) [0082] Viscosity at 60 C.: 2.2 Pa.Math.s

[0083] Reference 2

[0084] Hydroxylated Acrylate HA-2

[0085] The process is carried out as for reference HA-1, except that the pentaerythritol is replaced with DiTMP in the same molar amount, the criterion for stopping the esterification being an acid number of the reaction mixture of 52 mg KOH/g (that is to say 6.7% of residual AA).

[0086] A hydroxylated polyacrylate product HA-2 having the following characteristics is obtained: [0087] Appearance: clear [0088] Viscosity at 25 C.: 1000 mPa.Math..s [0089] OH number of the product: 120.0 mg KOH/g

[0090] Reference Urethane Acrylate Ref-U2

[0091] The process is carried out as for reference Ref-U1, except that the hydroxylated acrylate HA-1 is replaced with the hydroxylated acrylate HA-2 in the same OH equivalent amount. A reference urethane acrylate Ref-U2 having the following characteristics is obtained: [0092] Appearance: clear [0093] Viscosity at 60 C.: 2.3 Pa.Math.s

2) Preparation of the Products According to the Invention

2.1) Procedure for Examples According to the Invention

[0094] The ratios r1 and r2 mentioned below in the examples correspond: [0095] r1, to the ratio of Acrylate/NH equivalents [0096] r2, to the ratio of OH/NCO equivalents.

Example 1

Preparation of a Urethane Aminoacrylate-Acrylate (UAmAA-1)

[0097] The following are introduced, at ambient temperature, into a 1-liter reactor equipped with an anchor stirrer, with an air inlet (air sparge for inhibition of the free-radical polymerization), with a dropping funnel and with a thermometer probe: 634.66 g of TMPTA (2.144 mol), 2.0 g of MEHQ (2000 ppm), 2.0 g of TPPte (2000 ppm) and 0.2 g of PTZ (200 ppm).

[0098] The reaction mixture is gradually brought to 50 C. until the stabilizers have completely dissolved. 160.81 g of NMEA (2.144 mol; r1=3.00) are then gradually added via the dropping funnel (dropwise over the course of one hour). The reaction mixture is maintained at 50 C. until complete conversion of the secondary amines is obtained, that is to say until a total amine number corrected for the content of tertiary amine N.sub.AmT-N.sub.Am3<0.5 mg KOH/g is obtained, that is to say for approximately 2 hours.

[0099] 198.33 g of IPDI (0.893 mol; r2=1.20) are then added via the dropping funnel over the course of one hour, while controlling the exothermicity through an increase in temperature from 50 C. to 100 C., then the reaction mixture is maintained at this temperature until stabilization of the viscosity at 60 C. and NNCO<0.3 mg KOH/g, that is to say approximately 4 hours.

[0100] A product UAmAA-1 having the following characteristics is obtained: [0101] Appearance: clear [0102] Viscosity: 7.5 Pa.Math.s at 60 C. [0103] Aminoacrylate content: 2.16 mEq/g (that is to say an amine number of 121 mg KOH/g) [0104] Acrylate content: 4.31 mEq/g [0105] Number-average functionality: 4.80 acrylates per mol.

Example 2

Preparation of a Urethane Aminoacrylate-Acrylate (UAmAA-2)

[0106] The process is carried out as in example 1 except that the TMPTA is replaced with DiTMPTA in the same molar amount with r1=4.0 and r2=1.2.

Example 3

Preparation of a Urethane Aminoacrylate-Acrylate (UAmAA-3)

[0107] The process is carried out as in example 1 except that the TMPTA is replaced with PETTA in the same molar amount with r1=4.0 and r2=1.2.

[0108] The characteristics of these 3 examples and of the 2 reference products are collated in table 2 below.

TABLE-US-00002 TABLE 2 references and examples according to the invention Parameter Unit Ref-U1 Ref-U2 UAmAA-1 UAmAA-2 UAmAA-3 Acrylate a2) HA-1 HA-2 TMPTA DiTMPTA PETTA Amino alcohol NMEA NMEA NMEA a1) Isocyanate b) IPDI IPDI IPDI IPDI IPDI MM1 g/mol 298 412 296 482 352 MM2 g/mol 75 75 75 MM3 g/mol 222 222 222 222 222 r1 3 4 4 r2 1.00 1.00 1.20 1.20 1.20 fa.sub.2 Eq 4 4 3 4 4 Acrylate/mol fb Eq NCO/mol 2 2 2 2 2 Mn g/mol 818 1046 1112.4 1558.8 1246.8 Viscosity Pa .Math. s 2.2 2.1 7.5 13.0 13.2 (60 C.) tAa Eq AmAcr/mol 2.16 1.54 1.92 .sub.fAcr Eq Acr/mol 6 6 4.80 7.20 7.20 d.sub.A mEq Acr/gram 7.33 5.74 4.31 4.62 5.77 N.sub.AmT mg KOH/g 0 0 121.0 86.4 108.0

[0109] Measurement and Characterization Methods

[0110] Determination of the appearance: The product is observed visually in daylight, through a 60 ml white glass flask, and it is distinguished whether the product is: [0111] Clear: if no haze, it is comparable to water, [0112] Foggy: no longer allows clear vision through the flask, [0113] Cloudy: opaque flask, no image can be perceived through the flask.

[0114] Determination of the Noury viscosity: The time taken for a steel ball subjected to its gravity to travel through the liquid to be characterized is measured. The standard AFNOR XP.T51-213 specifies in particular the geometry of the container, the diameter of the ball (2 mm) and the distance to be travelled by the ball (104 mm). Under these conditions, the dynamic viscosity is proportional to the travel time of the ball, with a travel time of 1 second corresponding to a viscosity of 0.1 Pa.Math.s.

[0115] Determination of the hydroxyl number N.sub.OH: The hydroxyl number of the product to be characterized is expressed in mg KOH equivalent per gram of product. For this, an acid-base back titration of the excess acetic anhydride relative to the hydroxyl functions is carried out under the following conditions: an exact weight w of product (approximately 1 gram) is dissolved in exactly 10 ml of acetylating solution (mixture of 555 ml of ethyl acetate, 60 ml of acetic anhydride and 7 g of para-toluenesulfonic acid monohydrate). The mixture is left to react for 30 minutes at 90 C. After cooling, approximately 2 ml of water are added and the mixture is left to react for 2 minutes at ambient temperature. Approximately 10 ml of hydrolyzing solution (mixture of 600 ml of pyridine and 400 ml of water) are then added and the mixture is left to react for 5 minutes at ambient temperature. Approximately 60 ml of solvent (mixture of 666 ml of n-butanol and 333 ml of toluene) are added. The excess acetic acid (released by the hydrolysis of the excess acetic anhydride relative to the hydroxyl functions to be acetylated) is then titrated using methanolic potassium hydroxide having an exact normal titer N (Eq/1) of approximately 0.5 N. The equivalent point is detected using a combined electrode (LiCl METROHM reference 6.0222.100) servo-controlling an automatic burette (Metrohm 716 DMS Titrino automatic titration device) delivering the equivalent volume V.sub.E. A test with a blank (identical to the protocol above without the product to be analyzed), is also carried out with an equivalent volume V.sub.B. The hydroxyl number (N.sub.OH) is calculated using the following formula:

N.sub.OH=N.sub.A+[(V.sub.BV.sub.E).N.56.1/w]

with V.sub.E and V.sub.B in ml, N in Eq/1 and w in grams.

[0116] Determination of the acid number N.sub.A: The acid number of the product to be characterized is expressed in milligrams of potassium hydroxide equivalent per gram of product. For this, an acid-base titration is carried out under the following conditions: an exact weight w of product (approximately 10 grams) is dissolved in 50 ml of a toluene/ethanol mixture (2 vol/1 vol). After complete dissolution, the solution is titrated with a solution of methanolic potassium hydroxide having an exact normal titer N (Eq/1) of approximately 0.1 N. The equivalent point is detected using a combined electrode servo-controlling an automatic burette (Metrohm 716 DMS Titrino automatic titration device) delivering the equivalent volume V.sub.E. After carrying out a test with a blank (50 ml of the toluene/ethanol mixture alone), which makes it possible to determine the equivalent volume V.sub.B, the acid number (NA) is calculated using the following formula:

N.sub.A=(V.sub.EV.sub.B).N.56.1/w

with V.sub.E and V.sub.B in ml, N in Eq/1 and w in grams.

[0117] Determination of the isocyanate number N.sub.NCO: The isocyanate number of the product to be characterized is expressed in mg KOH equivalent per gram of product. For this, an acid-base back titration of the excess dibutyl amine relative to the isocyanate functions is carried out under the following conditions: an exact weight w of product (approximately 1 gram) is dissolved in approximately 50 ml of toluene. After complete dissolution, exactly 15 ml of a dibutyl amine solution having a titer of approximately 0.15 N (solution of 20 g of dibutyl amine in 1000 ml of toluene: 20 g/l) are added, and the mixture is then left to react for 15 min at ambient temperature. The excess dibutyl amine is then titrated with an aqueous solution of hydrochloric acid having an exact normal titer N (Eq/1) of approximately 0.1 N. The equivalent point is detected using a combined electrode (Metrohm LiCl reference 6.0222.100) servo-controlling an automatic burette (Metrohm 716 DMS Titrino automatic titration device) delivering the equivalent volume V.sub.E. A test with a blank (15 ml of dibutyl amine solution to which 50 ml of toluene has been added) is also carried out with an equivalent volume V.sub.B. The isocyanate number (N.sub.NCO) is calculated using the following formula:

N.sub.NCO=(V.sub.EV.sub.B).N.56.1/w

with V.sub.E and V.sub.B in ml, N in Eq/1 and w in grams.

[0118] Determination of the total amine number N.sub.AmT: This amine number encompasses the residual secondary amine undergoing reaction (if the case for samplings), the tertiary amine possibly introduced by the starting amino alcohol and the tertiary amine of the aminoacrylate formed. The total amine number of the product to be characterized is expressed in mg KOH equivalent per gram of product. For this, a direct acid-base titration is carried out under the following conditions: an exact weight w of product (exactly 1 gram) is dissolved in approximately 40 ml of glacial acetic acid. The basicity is titrated with a solution of perchloric acid in glacial acetic acid having an exact normal titer N (in Eq/1) of approximately 0.1 N. The equivalent point is detected using a glass electrode (filled with a solution of lithium perchlorate at 1 mol per liter in glacial acetic acid) servo-controlling an automatic burette (716 DMS Titrino Metrohm automatic titration device) delivering the equivalent volume V.sub.E. The total amine number (N.sub.AmT) is calculated using the following formula:

N.sub.AmT=V.sub.E.N. 56.1/w

with V.sub.E in ml, N in Eq/1 and w in grams.

[0119] Determination of the tertiary amine number N.sub.Am3: The tertiary amine number of the product to be characterized is expressed in milligrams of potassium hydroxide equivalent per gram of product. For this, a direct acid-base titration of the tertiary amine functions is carried out (after an excess of acetic anhydride has converted the primary and secondary amines into amides that cannot be salified by perchloric acid) under the following conditions: an exact weight w of product (approximately 1 gram) is introduced into approximately 10 ml of acetic anhydride. This is left to react for 5 min at ambient temperature, and is then diluted by adding approximately 50 ml of dichloromethane. The basicity is then titrated with a solution of perchloric acid in dichloromethane having an exact normal titer N (in Eq/1) of approximately 0.1 N. The equivalent point is detected using a glass electrode (filled with a solution of lithium perchlorate at 1 mol (1 Eq) per liter in glacial acetic acid) servo-controlling an automatic burette (716 DMS Titrino Metrohm automatic titration device) delivering the equivalent volume V.sub.E. The total amine number (N.sub.Am3) is calculated using the following formula:

N.sub.Am3=V.sub.E.N.56.1/w

with V.sub.E in ml, N in Eq/1 and w in grams.

3) Formulation and Evaluation of Photo-Curable Coatings (Varnishes)

3.1) Under Fusion Lamp

[0120] The following centesimal composition mixture is prepared by simple mixing at ambient temperature: [0121] Acrylate: 96.0 [0122] DC 1173: 4.0

[0123] A formulation for photo-curing under a UV fusion lamp F-fus is obtained, the comparative results of which are collated in table 3 below.

TABLE-US-00003 TABLE 3 Photo-curing by Fusion lamp Parameter Unit Ref-U1 Ref-U2 UAmAA-1 UAmAA-2 UAmAA-3 Reactivity m/min 55 10 45 50 60 Persoz second 320 330 207 251 303 hardness Flexibility mm >25 >25 10 20 >25 Acetone second >300 >300 >300 >300 >300 resistance Curling to ++ + ++ + Shrinkage % 9.4 6.0 4.5 2.5 4.4

3.2) Under LED Lamp

[0124] The following centesimal composition mixture is prepared by simple mixing at ambient temperature: [0125] Acrylate: 94.5 [0126] TPO: 2.5 [0127] DETX: 3.0

[0128] A formulation for photo-curing under an LED lamp F-led is obtained, the comparative results of which are collated in table 4 below.

TABLE-US-00004 TABLE 4 Photo-curing by LED lamp Parameter Unit Ref-U1 UAmAA-1 UAmAA-2 UAmAA-3 Reactivity m/min 5 40 20 55 Persoz second 333 245 274 292 hardness Flexibility mm 25 8 10 16 Acetone second 300 300 300 300 resistance

[0129] Tests and Methods Used

[0130] Determination of the reactivity under fusion lamp: The F-fus formulation is applied in a film of 12 m on a contrast card (Penoparc charts form 1B Leneta), and is then cured by means of a Hg Fusion lamp at 120 W/cm.sup.2. The minimum passage speed required (in m/min) in order to obtain a film that is dry to the touch is measured.

[0131] Determination of the reactivity under LED: The F-led formulation is applied in a film of 12 m on a contrast card (Penoparc charts form 1B Leneta), and is then cured by means of an LED lamp of wavelength =395 nm at 12 W/cm.sup.. The minimum passage speed required (in m/min) in order to obtain a film that is dry to the touch is measured.

[0132] For the following hardness, flexibility and acetone resistance tests, the photo-cured films are left in an air-conditioned room (T=23 C.) for 24 hours after curing and before the measurements.

[0133] Determination of the Curling: The formulation is applied in a film of 12 m on a contrast card (Penoparc charts form 1B Leneta), and is then cured by means of a Hg Fusion lamp at 120 W/cm at 5 m/min in order to obtain a film that is dry to the touch.

[0134] The curving of the Leneta cards is then evaluated comparatively (semiquantitatively): [0135] Very curled () [0136] Curled () [0137] Slightly curled (+) [0138] Flat (++)

[0139] Determination of the Shrinkage

[0140] Preparation of the film: The formulation is applied as a film of 200 m on a non-stick siliconized substrate, and then pre-cured under UV by means of a Hg Fusion lamp at 120 W/cm at 50 m/min. The film thus obtained is detached from the substrate, then placed between 2 glass plates for complete curing by means of 5 passages at 5 m/min under UV using a Hg Fusion lamp at 120 W/cm.

[0141] Density measurement: The density d.sub.m of the acrylate monomer is measured with a pycnometer before curing (liquid, at 25 C.) and then the density d.sub.p of the polymer after curing as described above (solid, 25 C.) is measured using a Mettler Toledo XS204 DeltaRAnge balance.

[0142] Calculation of the shrinkage of volume: The shrinkage of volume Rv is calculated using the following formula: Rv (%)=100.(d.sub.pd.sub.m)/d.sub.p.

[0143] Determination of the Persoz hardness according to standard ISO 1522: The formulation to be examined is applied as a film of 100 m on a glass plate and cured using a Hg Fustion lamp at 120 W/cm at a speed of 8 m/min.

[0144] The number of oscillations before damping of the oscillations (passing from an amplitude of 12 to 4) of a pendulum in contact with the coated glass plate is measured, according to standard ISO 1522.

[0145] Determination of the flexibility: The formulation is applied as a film of 100 m on a smooth steel plate 25/10 mm thick (D-46 Q-Panel), and then cured using a Hg Fustion lamp at 120 W/cm at a speed of 8 m/min.

[0146] The coated plate is bent onto cylindrical mandrels according to standard ISO 1519. The result is expressed by the value (in mm) of the smallest radius of curvature that can be inflicted on the coating without it cracking, or detaching from the support.

[0147] Determination of the acetone resistance: The formulation is applied as a film of 12 m on a glass plate and then cured using a Hg Fustion lamp at 120W/cm at a speed of 8 m/min. The coating is rubbed with an acetone-soaked cloth. The result is the time (expressed in seconds) beyond which the film detaches and/or disaggregates.

[0148] Calculation of the number-average molecular weight Mn: The average molecular weight of the UAmAA is given in g/mol (Daltons) by the following formula:

Mn=r1.r2/fa2).fb.MM1+r2.fb.MM2+MM3

MM1, MM2 and MM3 being the respective molar masses of the acrylate a2), of the hydroxylated amine (amino alcohol) a1) and of the polyisocyanate b).

[0149] Calculation of the number-average acrylate functionality (in Eq acrylate/mol):

f.sub.Acr=r2fb.(r11)

[0150] Calculation of the aminoacrylate group content (in mEq/g):

t.sub.Aa=1000.r2.fb/M

[0151] Calculation of the acrylate density (in mEq/g):

d.sub.A=1000.r2.fb.(r11)/M