MONOFUNCTIONAL OR MULTIFUNCTIONAL URETHANE ACRYLATE OLIGOMERS WITHOUT ISOCYANATES

Abstract

The present invention relates to an acrylated and/or methacrylated urethane oligomer obtained by reaction of a specific polyamine a) with a cyclic carbonate compound b) carrying m cyclic carbonate groups, giving an intermediate product c) carrying m formed urethane groups which carry residual reactive amine —NH— groups, and subsequently an addition reaction of each of the said residual reactive amine groups of the said product c) with an acrylate group of a compound d) carrying, in addition to the said acrylate group, p additional acrylate and/or methacrylate groups, with each residual reactive amine —NH— group of the said product c) being thus converted into a carbon-nitrogen bond carrying the said acrylate and/or methacrylate groups, and thus production of the said urethane oligomer, with each carbon-nitrogen bond formed carrying p acrylate and/or methacrylate groups and the said urethane oligomer carrying m urethane groups and m hydroxyl groups in the alpha or beta position with respect to the said urethane and having a functionality in acrylates and/or methacrylates ranging from m*p(n−1) to m*p(2n−2).

The invention also relates to a process for the preparation of the said oligomer in two stages, to the intermediate product c) and to the use of the said urethane oligomer in crosslinkable compositions, in particular in coating compositions, adhesive compositions, compositions for systems for the layer-by-layer manufacture of 3D objects, compositions for 3D printing systems, moulding compositions, leaktightness agent compositions, chemical sealing compositions, concrete compositions or composite compositions.

Claims

1. Urethane oligomer which is monofunctional or multifunctional in acrylates and/or methacrylates, preferably acrylates, which can be obtained from the reaction of a specific polyamine a) with a cyclic carbonate compound b) carrying m cyclic carbonate groups, the said polyamine being in stochiometric excess with respect to b) and the said reaction giving an intermediate product c) carrying m formed urethane groups, which groups carry residual reactive amine —NH— groups, and subsequently by an addition reaction of each of the said residual reactive amine groups of the said product c) with an acrylate group of a compound d) carrying, in addition to the said acrylate group, p additional acrylate and/or methacrylate groups, with each residual reactive amine —NH— group of the said product c) being thus converted into a carbon-nitrogen bond carrying the said acrylate and/or methacrylate groups, and thus production of the said urethane oligomer, with: the said polyamine a) carrying n primary and/or secondary amine groups and optionally at least one tertiary amine group, with n ranging from 2 to 5, preferably from 2 to 4 and more preferably from 2 to 3, more preferably still of 2, the said carbonate b) carrying m cyclic carbonate groups with m ranging from 1 to 2, the ring of the said cyclic carbonate groups preferably being a ring having 5 or 6 atoms, the said intermediate product c) carrying m urethane groups and m OH groups in the alpha or beta position with respect to the said urethane group and c) carrying from m*(n−1) to m*(2n−2) residual reactive amine —NH— groups, the said compound d) carrying p acrylate and/or methacrylate groups in addition to the said acrylate group which reacts with one of the said residual reactive amine —NH— groups, with p being at least equal to 1 and preferably at least equal to 2, and the number of the said residual reactive amine —NH— groups of the said product c) being less than or equal to the number of moles of the said compound d), each carbon-nitrogen bond formed carrying p acrylate and/or methacrylate groups and the said urethane oligomer carrying m urethane groups and m hydroxyl groups in the alpha or beta position with respect to the said urethane and having a functionality in acrylates and/or methacrylates ranging from m*p(n−1) to m*p(2n−2).

2. Oligomer according to claim 1, characterized in that the said n primary and/or secondary amine groups of the said polyamine a) can be carried by a radical A of valency n, which radical A can be or comprise an aliphatic, cycloaliphatic or aromatic structure with, in the latter case, the said n amine groups being carried by at least one alkylene group attached to the aromatic nucleus, and the rings of the said m cyclic carbonate groups of the said carbonate b) have 5 or 6 atoms and are carried by a radical R.sub.3 of valency m, with R.sub.3 being a hydrocarbon radical of aliphatic, cycloaliphatic or aromatic structure and optionally hydroxylated or R.sub.3 can be a simple hydrogen when m=1; optionally, the carbonate ring can be substituted by an optionally hydroxylated hydrocarbon substituent R.sub.4, it being possible for R.sub.4 to be of aliphatic, cycloaliphatic or aromatic structure identical to or different from that of R.sub.3 and it optionally being possible for R.sub.4 to form a ring attached to the carbonate ring by two common carbon atoms.

3. Oligomer according to claim 1 or 2, characterized in that the said polyamine a) is chosen from: a C.sub.2 to C.sub.54 alkylenepolyamine, the said alkylene being a linear or branched C.sub.2 to C.sub.54 alkylene and carrying the said n primary and/or secondary amine groups, a polyamine comprising at least two repeat units from: C.sub.2 to C.sub.4 alkyleneimine, in particular ethyleneimine or propyleneimine, preferably ethyleneimine, the said polyamine a) being in this case an oligoalkyleneiminepolyamine, in particular a polyethyleneiminepolyamine, including of dendritic structure, a polyamine comprising one or more units from: ether, ester-amide or amide, with, in the case of the presence of several units, the said polyamine a) being chosen from: oligoether polyamines, oligoester amide-polyamines or multiester amidepolyamines.

4. Oligomer according to one of claims 1 to 3, characterized in that the said polyamine a) is chosen from polyamines of following formulae a1) and a2): a1) R.sub.1—NH—R.sub.2—(NH—R)(NH—R′).sub.n1, with n.sub.1 being equal to 3, 2, 1 or 0 and preferably n.sub.1 being equal to 2, 1 or 0, a2) R.sub.1—NH—(R′.sub.2NH).sub.n2—R″.sub.2—NH—R′ with n.sub.2 being equal to 3, 2 or 1, with R.sub.1 and R and R′ being independently chosen from: H, alkyl, preferably C.sub.1-C.sub.3 alkyl, the said alkyl optionally being alkoxylated or a cycloalkyl, with it being possible for R.sub.1 to be identical to or different from R and R′ and with it being possible for R and R′ to be identical or different and in particular with R and/or R′ being different from H, R.sub.2 being alkylene or cycloalkylene (comprising an aliphatic C.sub.6 ring) or aralkylene of valency n ranging from 2 to 5, with it being possible for R.sub.2 to carry or comprise at least one tertiary amine group, and it being possible for R′.sub.2 and R″.sub.2 to be identical or different and to be chosen from alkylenes, preferably C.sub.2 to C.sub.8 alkylenes and more preferably C.sub.2 to C.sub.6 alkylenes, and, if R″.sub.2 is different from R′.sub.2, in this case it being possible for R″.sub.2 to carry or comprise at least one tertiary amine group.

5. Oligomer according to one of claims 1 to 4, characterized in that the said carbonate b) is a complete or partial ester of a monomeric or oligomeric polyacid, such as an oligoester polyacid, with a hydroxylated carbonate, preferably glycerol carbonate, or b) is a complete or partial ether of a monomeric or oligomeric polyol, such as oligoester or oligoether polyol, with a hydroxylated carbonate, preferably glycerol carbonate, or b) is a complete or partial ether of a phenolic derivative, including bisphenol A or dihydroxyphenylene, with a hydroxylated carbonate, preferably glycerol carbonate, or b) is an ether of allyl or vinyl alcohol with a hydroxylated carbonate, preferably glycerol carbonate or a methacrylate of a hydroxylated carbonate, preferably glycerol carbonate, or b) is a carbonate obtained by addition of CO.sub.2 to a precursor monomeric or oligomeric epoxidized compound or b) is the product of the reaction of dimethyl carbonate with an aliphatic or cycloaliphatic polyol with a functionality of at least 2, preferably ranging from 2 to 6.

6. Oligomer according to one of claims 1 to 5, characterized in that the said compound d) is represented overall by R.sub.5—(O.sub.2CCH═CH.sub.2)(—O.sub.2CC(R.sub.6)═CH.sub.2).sub.p with R.sub.5 being a hydrocarbon residue of valency p+1 and R.sub.6 being H or methyl for a portion or all of the p groups, and preferably R.sub.5 is a polyol residue chosen from optionally alkoxylated and/or substituted alkylene polyol, optionally substituted cycloalkylene polyol or aralkylene polyol optionally alkoxylated and/or substituted on the aromatic ring or polyether polyol or polyester polyol or R.sub.5 is a residue of a multifunctional epoxy acrylate compound carrying an acrylate group and p additional acrylate and/or methacrylate groups.

7. Oligomer according to one of claims 1 to 6, characterized in that the said polyamine a) is a diamine.

8. Oligomer according to one of claims 4 to 7, characterized in that the carbonate ring of the said carbonate b) has 5 atoms, that the said polyamine a) is a secondary-primary diamine according to formula a1) defined according to claim 4, with n.sub.1=0 and R═H, and that the said oligomer comprises at least one oligomer of following general formula (I):
[(CH.sub.2═CH(R.sub.6)—CO.sub.2).sub.p—R.sub.5—O.sub.2C—CH.sub.2—CH.sub.2—N(R.sub.1)—R.sub.2—NH—CO.sub.2—C(R.sub.4)—].sub.mR.sub.3  (I) with R.sub.1 being as defined according to claim 4, R.sub.2 being as defined according to claim 4, R.sub.3 being as defined according to claim 2, R.sub.4 being as defined according to claim 2, R.sub.5 being as defined according to claim 7, R.sub.6 being H or methyl or H and methyl if p is other than 1.

9. Oligomer according to one of claims 4 to 7, characterized in that the said carbonate ring of the said carbonate b) has 6 atoms, that the said polyamine a) is a secondary-primary diamine according to formula a1) as defined in claim 4, with n.sub.1=0 and R═H, and that the said oligomer comprises at least one oligomer of following general formula (II):
[(CH.sub.2═CH(R.sub.6)—CO.sub.2).sub.p—R.sub.5—O.sub.2C—CH.sub.2—CH.sub.2—N(R.sub.1)—R.sub.2—NH—CO.sub.2—C(R.sub.4)—CH.sub.2CH(OH)—].sub.mR.sub.3  (II) with R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 being as defined according to claim 8.

10. Oligomer according to one of claims 1 to 7, characterized in that the said polyamine a) is a diamine selected from secondary-primary, primary-primary or secondary-secondary diamines, preferably secondary-primary or secondary-secondary diamines.

11. Oligomer according to claim 10, characterized in that the said diamine is selected from secondary-primary diamines, preferably from: N-methyl-1,3-propanediamine, N-methylethanediamine, N-methyl-1,4-butanediamine or N-methyl-1,5-pentanediamine.

12. Oligomer according to claim 10, characterized in that the said diamine is selected from secondary-secondary diamines, preferably from: N-methyl-N′-methyl-1,3-propanediamine, N-methyl-N′-methylethanediamine, N-methyl-N′-methyl-1,4-butanediamine or N-methyl-N′-methyl-1,5-pentanediamine.

13. Oligomer according to one of claims 4 to 7, characterized in that the said polyamine a) is an amine according to formula a2) as defined according to claim 4, with n.sub.2=1 and R.sub.1 and R′ being H and R′.sub.2 and R″.sub.2 being identical or different C.sub.2 to C.sub.6 alkylenes, in particular C.sub.2 to C.sub.4 alkylenes, the said amine a2) being more particularly selected from 3-[(2-aminoethyl)amino]propylamine or bis(3-aminopropyl)amine.

14. Oligomer according to one of claims 4 to 7, characterized in that the said polyamine a) is an amine according to formula a2) as defined according to claim 4, with n.sub.2=2 or 3 and R.sub.1 and R′ being H and R′.sub.2 and R″.sub.2 being identical C.sub.2 to C.sub.4 alkylenes, in particular C.sub.2 to C.sub.3 alkylenes, the said amine a2) being more particularly selected from triethylenetetramine or tetraethylenepentamine.

15. Oligomer according to one of claims 1 to 14, characterized in that the said compound d) is a multifunctional acrylic monomer having a functionality of at least 2, in particular greater than 2 and ranging up to p+1 equal to 6 and selected from: d1) acrylate esters of alkoxylated or nonalkoxylated polyols, preferably polyols chosen from the group: trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, diethylene glycol, dipropylene glycol, tripropylene glycol, glycerol, propylene glycol, butanediol and hexanediol, or d2) epoxy acrylates, d3) aminoacrylates.

16. Oligomer according to one of claims 1 to 14, characterized in that the said compound d) is a multifunctional acrylic oligomer having a functionality of at least 2, in particular greater than 2 and ranging up to p+1 equal to 12 and selected from: d4) acrylated acrylic oligomer which can be an acrylated glycidyl methacrylate copolymer or acrylated styrene oligomer which can be a copolymer of styrene with maleic anhydride or acrylic acid which is acrylated by hydroxyethyl acrylate, d5) acrylated hydroxylated oligomer, in particular from acrylated hydroxylated polydienes, preferably acrylated hydroxylated polybutadiene and more preferably acrylated hydrogenated hydroxylated polybutadiene, d6) acrylated epoxidized oil, d7) acrylated epoxidized oligodiene, d8) oligoether acrylates, d9) oligoester acrylates, d10) oligoaminoacrylates.

17. Oligomer according to one of claims 1 to 16, characterized in that the functionality f in acrylate and/or methacrylate groups varies from 1 to 30, with f=1 if monofunctional, preferably multifunctional oligomer with a functionality f ranging from 2 to 20, more particularly from 3 to 20.

18. Oligomer according to one of claims 1 to 17, characterized in that p varies from 1 to 11, preferably from 2 to 11, more preferably from 2 to 5, more preferably still being greater than 2 and ranging up to 5.

19. Oligomer according to one of claims 1 to 18, characterized in that m=2 and that p varies from 2 to 11 and preferably p varies from 3 to 5.

20. Oligomer according to one of claims 1 to 19, characterized in that the said compound d) is in molar excess with respect to the amine —NH— groups of the said intermediate product c) and with the said residual compound d) being present in the said oligomer as reactive diluent.

21. Urethane oligomer of linear or branched structure carrying one or more acrylate and/or methacrylate groups, in particular carrying at least two acrylate and/or methacrylate groups and more particularly carrying more than two acrylate and/or methacrylate groups, the said oligomer being characterized in that it comprises at least one oligomer with a structure according to the following general formula (III):
(Acr).sub.p-R.sub.5—O.sub.2C—CH.sub.2—CH.sub.2—(R.sub.7)N-A-U—R.sub.3[—U-A-[—N(R.sub.7)—CH.sub.2—CH.sub.2—CO.sub.2—R.sub.5-(Acr).sub.p].sub.n-1].sub.m-1, with Acr: acrylate or methacrylate group, R.sub.5: residue of a compound d) carrying an acrylate group and p additional acrylate and/or methacrylate groups, with p equal to at least 1, in particular with d) and R.sub.5 being as defined according to one of claims 1, 6, 15 and 16, A: residual of polyamine as defined according to a) in one of claims 1 to 4, 7 to 14 and 19, carrying n secondary or primary amine groups, with n ranging from 2 to 5, R.sub.3: residual of carbonate b) carrying m cyclic carbonate groups having 5 or 6 atoms, with m ranging from 1 to 2, the said residual optionally being hydroxylated and/or the said carbon ring optionally being substituted, in particular with b) and R.sub.3 being as defined according to one of claims 1, 2, 5, 8, 9 and 19, R.sub.7: cycloalkyl or C.sub.1-C.sub.3 alkyl, if secondary amine or R.sub.7: —CH.sub.2—CH.sub.2—CO.sub.2—R.sub.5-(Acr).sub.p, if primary amine, Acr: acrylate or methacrylate or acrylate+methacrylate mixture, U: urethane bond formed by cyclic carbonate-secondary amine (—NH—) or primary amine (—NH.sub.2) reaction, with an OH in the beta or gamma position as a function of the number of atoms of the carbonate ring respectively having 5 or 6 atoms.

22. Process for the preparation of an oligomer as defined according to one of claims 1 to 20, characterized in that it comprises the following stages: i) reaction between the said polyamine a) as defined according to one of claims 1 to 4, 7 to 14 and 19 and the said carbonate compound b) carrying m cyclic carbonates as defined according to one of claims 1, 2, 5, 8, 9 and 19, the said polyamine being in stochiometric excess with respect to b) and being gradually added to the said carbonate b) present at the start in the reactor and the said reaction giving an intermediate product c) carrying m urethane groups and m hydroxyl groups in the alpha or beta position with respect to the said urethane and carrying the residual reactive amine —NH— groups, ii) reaction for the modification of the said compound c), by addition of each of the said residual reactive amine groups of the said product c) to an acrylate group of a compound d) carrying, in addition to the said acrylate group, p additional acrylate and/or methacrylate groups as defined according to one of claims 1, 6, 15 and 16, with each residual reactive amine —NH— group of the said product c) being thus converted into a carbon-nitrogen bond carrying the said acrylate and/or methacrylate groups, and thus production of the said urethane oligomer, with the said polyamine a) carrying n primary and/or secondary amine groups and optionally at least one tertiary amine group, with n ranging from 2 to 5, preferably from 2 to 4 and more preferably from 2 to 3, more preferably still of 2, the said carbonate b) carrying m carbonate groups with m ranging from 1 to 2, the ring of the said cyclic carbonate groups preferably being a ring having 5 or 6 atoms, the said intermediate product c) carrying m urethane groups and m hydroxyl groups in the alpha or beta position with respect to the said urethane and from m*(n−1) to m*(2n−2) residual reactive amine —NH-groups, the said compound d) carrying p acrylate and/or methacrylate groups in addition to the said acrylate group which reacts with one of the said residual reactive amine —NH— groups, with p being at least equal to 1 and preferably at least equal to 2, and the number of the said residual reactive amine —NH— groups being less than or equal to a number of moles of the said compound d), each carbon-nitrogen bond formed carrying p acrylate and/or methacrylate groups and the said urethane oligomer having a functionality of acrylates and/or methacrylates ranging from m*p(n−1) to m*p(2n−2).

23. Hydroxylated polyurethane-amine product, characterized in that it is the intermediate product c) of the reaction i) between the said polyamine a) as defined according to one of claims 1 to 4, 7 to 14 and 19 and the said carbonate b) as defined according to one of claims 1, 2, 5, 8, 9 and 19 or as obtained at the end of stage i) of the preparation process as defined according to claim 22.

24. Crosslinkable composition, characterized in that it comprises, as binder, at least one oligomer as defined according to one of claims 1 to 21 or as obtained by a process as defined according to claim 22.

25. Crosslinkable composition according to claim 24, characterized in that it can be crosslinked by the radiation route and/or by the thermal or low-temperature peroxide route and/or by the Michael-type addition route, in the case of oligomers carrying at least two acrylate functional groups, and/or by another dual route involving at least two of the routes mentioned and/or involving all or a portion of the m residual hydroxyl groups of the said oligomer, by reaction of these residual hydroxyl groups with a crosslinking agent which reacts with the said hydroxyls.

26. Crosslinkable composition according to claim 24 or 25, characterized in that it is a coating composition, preferably coatings from paints, varnishes and inks, a moulding composition, a leaktightness agent or chemical sealing composition, an adhesive composition, a composition for systems for the layer-by-layer manufacture of 3D objects, a composition for 3D printing systems, a concrete composition or a composite composition.

27. Use of an oligomer as defined according to one of claims 1 to 21 or obtained by the process as defined according to claim 22 as reactive binder in coating compositions, in particular paints, varnishes and inks, adhesive compositions, moulding compositions, leaktightness agent compositions, chemical sealing compositions, compositions for systems for the layer-by-layer manufacture of 3D objects, compositions for 3D printing systems, concrete compositions or composite compositions.

28. Finished product, characterized in that it results from the use of at least one oligomer as defined according to one of claims 1 to 21 or obtained by the process as defined according to claim 22, which product is preferably chosen from coatings, in particular paints, varnishes and inks, or from adhesive seals, moulded parts, 3D objects obtained layer-by-layer, 3D printings, leaktight seals, chemical sealing, finished concrete or composite articles.

Description

EXPERIMENTAL PART

1) Preparation of Oligomers According to the Invention

Example 1

[0109] 161.55 g of propylene carbonate (Huntsman Jeffsol, Mw of 102 g/mol), 0.81 g of tris(nonylphenyl) phosphite and 1 g of 2,6-di(tert-butyl)-4-methylphenol (BHT) are introduced into a 1 l reactor. 146.80 g of N-methyl-1,3-propanediamine (Aldrich, Mw of 88.15 g/mol) are added over one hour at a constant flow rate with stirring and bubbling with nitrogen. An exothermicity of approximately 30° C. is observed. At the end of the addition, the temperature of the mixture is brought to 60° C. After one hour at 60° C., while bubbling with air, 689.85 g of tripropylene glycol diacrylate (TPGDA, Sartomer SR306, Mw of 300 g/mol) are added to the mixture in fifteen minutes at a constant flow rate. At the end of the addition, the temperature of the mixture is brought to 85-90° C.

[0110] The progress of the reaction is monitored by a measurement of the total amine and tertiary amine numbers. The reaction is halted when the tertiary amine number=total amine number.

Example 2

[0111] 162.93 g of propylene carbonate (Huntsman Jeffsol, Mw of 102 g/mol), 0.81 g of tris(nonylphenyl) phosphite and 1 g of 2,6-di(tert-butyl)-4-methylphenol (BHT) are introduced into a 1 l reactor. 147.81 g of N-methyl-1,3-propanediamine (Aldrich, Mw of 88.15 g/mol) are added over one hour at a constant flow rate with stirring and bubbling with nitrogen. An exothermicity of approximately 30° C. is observed. At the end of the addition, the temperature of the mixture is brought to 60° C. After one hour at 60° C., while bubbling with air, 687.44 g of trimethylolpropane triacrylate (TMPTA, Sartomer SR351, Mw of 296 g/mol) are added to the mixture in fifteen minutes at a constant flow rate. At the end of the addition, the temperature of the mixture is brought to 85-90° C.

[0112] The progress of the reaction is monitored by a measurement of the total amine and tertiary amine numbers. The reaction is halted when the tertiary amine number=total amine number.

Example 3

[0113] 336.04 g of polyethylene oxide dicarbonate (Specific Polymers, Mw of 632.5 g/mol), 1.68 g of tris(nonylphenyl) phosphite and 2.07 g of 2,6-di(tert-butyl)-4-methylphenol (BHT) are introduced into a 1 l reactor. 95.38 g of N-methyl-1,3-propanediamine (Aldrich, Mw of 88.15 g/mol) are added over one hour at a constant flow rate with stirring and bubbling with nitrogen. An exothermicity of approximately 30° C. is observed. At the end of the addition, the temperature of the mixture is brought to 60° C. After one hour at 60° C., while bubbling with air, 564.84 g of trimethylolpropane triacrylate (TMPTA, Sartomer SR351, Mw of 296 g/mol) are added to the mixture in fifteen minutes at a constant flow rate. At the end of the addition, the temperature of the mixture is brought to 85-90° C.

[0114] The progress of the reaction is monitored by a measurement of the total amine and tertiary amine numbers. The reaction is halted when the tertiary amine number=total amine number.

2) Characteristics of the Products Prepared

[0115]

TABLE-US-00001 Characteristics Unit Example 1 Example 2 Example 3 Noury viscosity Pa .Math. s 2.0 (25° C.) 24 (50° C.) 12.3 (50° C.) Rate of m/min <10 50 >80 crosslinking under UV lamp Persoz hardness Number of 60 75 103 oscillations Flexibility mm N/DA 20 Resistance to s 10 >300 >300 acetone

[0116] The applicative properties are measured on a film crosslinked under a 120 W/cm “fusion” UV lamp starting from a mixture of urethane amino-acrylate according to the invention and Darocur® 1173 photoinitiator in the proportions of 96/4 w/w.

Methods Used

Determination of the Reactivity (Crosslinking Rate):

[0117] The mixture is applied as a 12 μm film to a contrast chart (Penoparc charts form 1B, Leneta) and is then crosslinked using a 120 W/cm Hg fusion lamp. The minimum rate of passage (in m/min) necessary in order to obtain a film dry to the touch is measured.

[0118] For the following tests of hardness, flexibility and resistance to acetone, the photocrosslinked films are left in a climate-controlled room (T=23° C.) for 24 hours after crosslinking and before the measurements.

Determination of the Persoz Hardness:

[0119] The mixture is applied as a 100 μm film to a sheet of glass and crosslinked by a 120 W/cm Hg fusion lamp at a rate of 8 m/min. The number of oscillations, before the oscillations die out (change from 12° to 40 in amplitude), of a pendulum in contact with the coated sheet of glass is measured according to Standard ISO 1522.

Determination of the Flexibility:

[0120] The mixture is applied as a 100 μm film to a smooth sheet of 25/100 mm in thickness (D-46 Q-Panel) and is then crosslinked by a 120 W/cm Hg fusion lamp at a rate of 8 m/min. The coated sheet is curved over cylindrical mandrels according to Standard ISO 1519. The result is expressed by the value (in mm) of the lowest radius of curvature which can be inflicted on the coating without it cracking or detaching from the support.

Determination of the Resistance to Acetone:

[0121] The mixture is applied as a 12 μm film to a sheet of glass and then crosslinked by a 120 W/cm Hg fusion lamp at a rate of 8 m/min. The coating is rubbed with a rag impregnated with acetone. The result is the time (expressed in seconds) beyond which the film detaches and/or disintegrates.