Polyaldimine and curable polyurethane composition

Abstract

A polyaldimine of the formula (I) with advantageous properties in use as latent hardener for compositions including isocyanate groups, and compositions containing the polyaldimine of the formula (I) and at least one polyisocyanate and/or at least one polyurethane polymer containing isocyanate groups. The polyaldimine of the formula (I) is odourless, pH-neutral, liquid at room temperature, has low viscosity, has little sensitivity to heat and moisture, and is stable in storage together with isocyanates. It can provide odourless single-component polyurethane compositions which have good stability in storage and which do not produce bubbles when hardened in the presence of moisture, and which cause no problematic odour emissions, giving a hardened elastic material with good mechanical properties and surprisingly little tendency towards plasticizer migration.

Claims

1. A polyaldimine of the formula (I) ##STR00008## where n is 2 or 3, Z is an aryl radical substituted by an alkyl and/or alkoxy group and having a total of 12 to 26 carbon atoms, and A is an n-valent aliphatic or cycloaliphatic hydrocarbyl radical optionally containing ether oxygen and having a molecular weight in the range from 42 to 6000 g/mol, bonded via at least one tertiary or quaternary carbon atom and/or containing a bi- or tricyclic ring system.

2. A polyaldimine as claimed in claim 1, wherein Z is a radical of the formula (II) ##STR00009## where R is a linear or branched alkyl radical having 10 to 14 carbon atoms.

3. A polyaldimine as claimed in claim 2, wherein R is branched.

4. A polyaldimine as claimed in claim 3, wherein R is a radical of the formula ##STR00010## where R.sup.1 and R.sup.2 are each an alkyl radical and together have 9 to 13 carbon atoms.

5. A polyaldimine as claimed in claim 1, wherein A is selected from the group consisting of 1,2-propylene, 1,3-pentylene, 2-methyl-1,5-pentylene, 2,2(4),4-trimethyl-1,6-hexamethylene, 1,2-cyclohexylene, (1,5,5-trimethylcyclohexan-1-yl)methane-1,3, 4(2)-methyl-1,3-cyclohexylene, methylenedicyclohexan-4-yl, methylenebis(2-methylcyclohexan-4-yl), (bicyclo[2.2.1]heptan-2,5(2,6)-diyl)dimethylene, (tricyclo[5.2.1.0.sup.2,6]decane-3(4),8(9)-diyl)dimethylene, ,-polyoxypropylene having an average molecular weight in the range from 170 to 5000 g/mol and trimethylolpropane- or glycerol-started tris(-polyoxypropylene) having an average molecular weight in the range from 330 to 6000 g/mol.

6. A reaction product containing at least one polyaldimine as claimed in claim 1, obtained from the reaction of at least one amine of the formula (III) with at least one aldehyde of the formula (IV) in a condensation reaction with release of water, wherein the aldehyde was present stoichiometrically or in a stoichiometric excess in relation to the primary amino groups ##STR00011##

7. A mixture of polyaldimines as claimed in claim 1, in which each Z is a radical of the formula (II) and R is selected from linear or particularly branched decyl, undecyl, dodecyl, tridecyl and tetradecyl radicals.

8. A method comprising latently hardening compositions containing isocyanate groups with at least one polyaldimine as claimed in claim 1.

9. The method as claimed in claim 8, wherein some or all of the isocyanate groups are derived from 4,4- or 2,4- or 2,2-diphenylmethane diisocyanate or any mixtures of these isomers.

10. A composition comprising at least one polyaldimine as claimed in claim 1 and at least one polyisocyanate and/or at least one polyurethane polymer containing isocyanate groups.

11. The composition as claimed in claim 10, wherein it comprises at least one polyurethane polymer containing isocyanate groups.

12. The composition as claimed in claim 11, wherein some or all of the isocyanate groups are derived from 4,4- or 2,4- or 2,2-diphenylmethane diisocyanate or any mixtures of these isomers.

13. The composition as claimed in claim 10, wherein it additionally comprises at least one further constituent selected from catalysts, fillers, plasticizers and solvents.

14. The composition as claimed in claim 10, wherein it is a one-component composition.

15. The composition as claimed in claim 10, wherein it is an adhesive or a sealant or a coating.

Description

EXAMPLES

(1) Adduced hereinafter are working examples which are intended to elucidate the invention described in detail. It will be appreciated that the invention is not restricted to these described working examples.

(2) Aldehydes Used: Aldehyde1: Fractionated reaction mixture obtained from formylation, catalyzed by means of HFBF.sub.3, of C.sub.10-14-alkylbenzene, containing mainly branched 4-(C.sub.10-14-alkyl)benzaldehydes. (mean aldehyde equivalent weight 290 g/eq)

(3) p-Decyloxybenzaldehyde (262.4 g/mol)

(4) 2,2-Dimethyl-3-lauroyloxypropanal (284.4 g/mol)

(5) Benzaldehyde (106.1 g/mol)

(6) p-tert-Butylbenzaldehyde (162.2 g/mol)

(7) 3-Phenoxybenzaldehyde (198.2 g/mol)

(8) Aldehyde-1 is a mixture of aldehydes of the formula (IV) and p-decyloxybenzaldehyde is an aldehyde of the formula (IV), whereas 2,2-dimethyl-3-lauroyloxypropanal, benzaldehyde, p-tert-butylbenzaldehyde and 3-phenoxybenzaldehyde do not conform to the formula (IV).

(9) Amines and Abbreviations Used: IPDA 3-aminomethyl-3,5,5-trimethylcyclohexylamine (Vestamin IPD from Evonik, 170.3 g/mol) NBDA 2,5(6)-bis(aminomethyl)bicyclo[2.2.1]heptane (PRO-NBDA from Mitsui Fine Chemicals, 154.3 g/mol) TCD 3(4),8(9)-di(aminomethyl)tricyclo[5.2.1.0(2.6)]decane (TCD diamine from Oxea, 194.3 g/mol) TMD 2,2,4- and 2,4,4-trimethylhexamethylenediamine (Vestamin TMD from Evonik, 158.4 g/mol) MPMD 1,5-diamino-2-methylpentane (Dytek A from Invista, 116 g/mol) 1,2-PDA 1,2-propylenediamine (from BASF, 74.1 g/mol) H.sub.12MDA 4,4-diaminodicyclohexylmethane (from BASF, 210.4 g/mol) T-403 polyoxypropylenetriamine having an average molecular weight of about 440 g/mol (Jeffamine T-403, from Huntsman, amine value 359 mg KOH/g) HDA hexane-1,6-diamine (from Invista, 116.2 g/mol) MXDA 1,3-bis(aminomethyl)benzene (from Mitsubishi Gas Chem., 136.2 g/mol) pPhDA 1,4-phenylenediamine (from Sigma-Aldrich, 108.2 g/mol)

(10) Preparation of Polyaldimines:

(11) The amine value (including aldimino groups) was determined by means of titration (with 0.1 N HClO.sub.4 in acetic acid versus crystal violet).

(12) The viscosity was measured with a thermostated Rheotec RC30 cone-plate viscometer (cone diameter 50 mm, cone angle 1, cone tip-plate distance 0.05 mm, shear rate 10 s.sup.1).

(13) Aldimine A1:

(14) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.93 g of IPDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 21.3 Pa.Math.s and an amine value of 150.1 mg KOH/g was obtained.

(15) Aldimine A2:

(16) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 12.62 g of NBDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 9.8 Pa.Math.s and an amine value of 152.3 mg KOH/g was obtained.

(17) Aldimine A3:

(18) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 15.90 g of TCD were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 19.6 Pa.Math.s and an amine value of 144.0 mg KOH/g was obtained.

(19) Aldimine A4:

(20) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 17.21 g of H.sub.12MDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 59.6 Pa.Math.s and an amine value of 140.2 mg KOH/g was obtained.

(21) Aldimine A5:

(22) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 12.95 g of TMD were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 1.6 Pa.Math.s and an amine value of 152.4 mg KOH/g was obtained.

(23) Aldimine A6:

(24) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 9.51 g of MPMD were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 1.2 Pa.Math.s and an amine value of 162.0 mg KOH/g was obtained.

(25) Aldimine A7:

(26) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 25.77 g of T-403 were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. An orange-yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 4.3 Pa.Math.s and an amine value of 126.8 mg KOH/g was obtained.

(27) Aldimine A8:

(28) 5.75 g of decyloxybenzaldehyde were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 1.78 g of IPDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A solid which was waxy at 20 C., odorless and pH-neutral with an amine value of 163.7 mg KOH/g and a melting point of 52 to 59 C. and a viscosity at 80 C. of 82.4 Pa.Math.s was obtained.

(29) Aldimine R1:

(30) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.58 g of HDA solution (70% by weight in water) were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 1.0 Pa.Math.s and an amine value of 161.6 mg KOH/g was obtained.

(31) Aldimine R2:

(32) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 11.14 g of MXDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A pale yellow, odorless and pH-neutral liquid having a viscosity at 20 C. of 2.6 Pa.Math.s and an amine value of 155.7 mg KOH/g was obtained.

(33) Aldimine R3:

(34) 50.00 g of aldehyde-1 were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 8.85 g of pPhDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. An orange-brown, odorless and pH-neutral liquid having a viscosity at 20 C. of 4.9 Pa.Math.s and an amine value of 163.0 mg KOH/g was obtained.

(35) Aldimine R4:

(36) 48.92 of 2,2-dimethyl-3-lauroyloxypropanal were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.93 g of IPDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A pale yellow, odorless liquid having an amine value of 153.0 mg KOH/g was obtained.

(37) Aldimine R5:

(38) 48.87 g of 2,2-dimethyl-3-lauroyloxypropanal were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 17.21 g of H.sub.12MDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. A light yellow, odorless liquid having a viscosity at 20 C. of 0.6 Pa.Math.s and an amine value of 145.4 mg KOH/g was obtained.

(39) Aldimine R6:

(40) 33.43 g of benzaldehyde were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 25.55 g of IPDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. What was obtained was a light yellow, intensely odorous liquid having an amine value of 314.1 mg KOH/g, which crystallized after a few days.

(41) Aldimine R7:

(42) 27.87 g of p-tert-butylbenzaldehyde were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.93 g of IPDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. What was obtained was a light yellow, intensely odorous, highly viscous liquid having an amine value of 236.2 mg KOH/g, which crystallized after a few days. The viscosity at 80 C. was 23.7 Pa.Math.s.

(43) Aldimine R8:

(44) 34.06 g of 3-phenoxybenzaldehyde were initially charged in a round-bottom flask under a nitrogen atmosphere. While stirring, 13.93 g of IPDA were added and then the volatile constituents were removed at 80 C. and a reduced pressure of 10 mbar. What was obtained was a light yellow, highly viscous liquid with low odor and having an amine value of 203.8 mg KOH/g, which crystallized after a few days. The viscosity at 80 C. was 5.1 Pa.Math.s.

(45) The aldimines A1 to A8 are polyaldimines of the formula (I). The aldimines R1 to R8 are comparative examples.

(46) Preparation of Polymers Containing Isocyanate Groups

(47) Polymer P1:

(48) 4000 g of polyoxypropylenediol (Acclaim 4200, from Covestro; OH number 28.5 mg KOH/g) and 520 g of diphenylmethane 4,4-diisocyanate (Desmodur 44 MC L, from Covestro) were reacted by a known method at 80 C. to give an NCO-terminated polyurethane polymer which is liquid at room temperature and has a content of free isocyanate groups of 1.85% by weight.

(49) Polymer P2:

(50) 3080 g of polyoxypropylenediol (Acclaim 4200, from Covestro; OH number 28.5 mg KOH/g), 1540 g of polyoxypropylenepolyoxyethylenetriol (Caradol MD34-02, from Shell; OH number 35.0 mg KOH/g) and 385 g of tolylene diisocyanate (Desmodur T 80 P, Covestro) were reacted at 80 C. by a known method to give an NCO-terminated polyurethane polymer which is liquid at room temperature and has a content of free isocyanate groups of 1.50% by weight.

(51) Polymer P3:

(52) 590 g of polyoxypropylenediol (Acclaim 4200, from Covestro; OH number 28.5 mg KOH/g), 1180 g of polyoxypropylenepolyoxyethylenetriol (Caradol MD34-02, from Shell; OH number 35.0 mg KOH/g) and 230 g of isophorone diisocyanate (Vestanat IPDI, Degussa) were reacted by a known method at 80 C. to give an NCO-terminated polyurethane polymer which is liquid at room temperature and has a content of free isocyanate groups of 2.10% by weight.

(53) Polymer P4:

(54) 300.0 g of polyoxypropylenepolyoxyethylenediol (Desmophen L300, from Covestro; OH number 190.0 mg KOH/g) and 228.8 g of isophorone diisocyanate (Vestanat IPDI, Degussa) were reacted by a known method at 60 C. to give an NCO-terminated polyurethane polymer which is liquid at room temperature and has a content of free isocyanate groups of 8.35% by weight.

(55) One-Component Compositions

(56) Compositions Z1 to Z15 and Ref1 to Ref10

(57) For each composition, the ingredients specified in tables 1 to 3 were mixed in the amounts specified (in parts by weight) by means of a centrifugal mixer (SpeedMixer DAC 150, FlackTek Inc.) with exclusion of moisture at 3000 rpm for one minute and stored with exclusion of moisture. Each composition was tested as follows:

(58) As a measure of storage stability, the Viscosity (1 d RT) was determined the day after production, and the Viscosity (7 d 60 C.) after storage in a closed container in an air circulation oven at 60 C. for 7 days. The viscosity was measured, at a temperature of 20 C. in each case, with a thermostated Rheotec RC30 cone-plate viscometer (cone diameter 50 mm, cone angle 1, cone tip-plate distance 0.05 mm, shear rate 10 s.sup.1). A significant rise in the viscosity on storage shows inadequate storage stability.

(59) As a measure of the open time, the Tack-free time was determined. For this purpose, a few grams of the composition were applied to cardboard in a layer thickness of about 2 mm and, under standard climatic conditions, the time until, when the surface of the composition was gently tapped by means of an LDPE pipette, there were for the first time no residues remaining any longer on the pipette was determined.

(60) To determine the mechanical properties, each composition was poured onto a PTFE-coated film to give a film of thickness 2 mm and stored under standard climatic conditions for 7 days, and a few dumbbells having a length of 75 mm with a bar length of 30 mm and a bar width of 4 mm were punched out of the film and these were tested in accordance with DIN EN 53504 at a strain rate of 200 mm/minute for Tensile strength (breaking force), Elongation at break, Modulus of elasticity 5% (at 0.5-5% elongation) and Modulus of elasticity 50% (at 0.5-50% elongation).

(61) Appearance was assessed visually on the films produced. Nice was used to describe a clear film with a nontacky surface without blisters.

(62) Odor was assessed by smelling by nose at a distance of 2 cm from the freshly produced films. No means that no odor was perceptible.

(63) The results are reported in tables 1 to 3.

(64) Compositions Z1 to Z15 are inventive examples. Compositions Ref1 to Ref10 are comparative examples.

(65) TABLE-US-00001 TABLE 1 Composition (in parts by weight) and properties of Z1 to Z7 and Ref1 to Ref8. Composition Z1 Z2 Z3 Z4 Z5 Z6 Z7 Polymer P1 80.00 80.00 80.00 80.00 80.00 80.00 80.00 Aldimine A1 A2 A3 A4 A5 A6 A8 9.20 8.98 9.48 9.67 9.03 8.52 8.44.sup.2 Salicylic acid solution.sup.1 1.50 1.50 1.50 1.50 1.50 1.50 1.50 Viscosity (1 d RT) 29.4 43.1 47.8 32.0 43.4 41.7 34.8 [Pa .Math. s] (7 d 60 C.) 34.8 65.3 69.5 37.5 50.3 57.9 42.3 Tack-free time 1 h 20 1 h 1 h 13 1 h 10 1 h 40 1 h 5 2 h 10 Tensile strength [MPa] 1.62 1.76 2.01 3.46 1.60 1.90 2.62 Elongation at break 1240 731 876 803 1373 942 1289 [%] Modulus of elasticity 0.75 0.94 0.97 1.27 0.61 0.85 1.03 5% [MPa] Modulus of elasticity 0.41 0.55 0.58 0.75 0.35 0.45 0.57 50% Appearance nice nice nice nice nice nice nice Odor no no no no no no no Composition Ref1 Ref2 Ref3 Ref4 Ref5 Ref6 Ref7 Ref8 Polymer P1 80.00 80.00 80.00 80.00 80.00 80.00 80.00 80.00 Aldimine R1 R2 R3 R4 R5 R6 R7 R8 8.56 8.76 8.42 9.03 9.51 4.40 5.85 6.78 Salicylic acid solution.sup.1 1.50 1.50 1.50 1.50 0.20 1.50 1.50 1.50 Viscosity (1 d RT) 50.0 50.5 35.7 22.1 28.6 36.5 43.8 39.9 [Pa .Math. s] (7 d 60 C.) 87.2 137.5 41.1 27.0 33.5 41.1 47.4 44.6 Tack-free time 1 h 10 35 1 h 30 45 1 h 22 1 h 30 2 h 1 h 35 Tensile strength [MPa] 2.91 3.47 2.10 1.18 1.62 1.66 1.44 0.55 Elongation at break 508 823 248 1240 299 936 1674 1098 [%] Modulus of elasticity 5.66 6.72 10.30 1.02 1.61 1.00 0.79 0.41 5% [MPa] Modulus of elasticity 1.82 1.70 1.81 0.54 0.95 0.51 0.40 0.17 50% Appearance nice nice nice nice nice nice nice nice Odor no no no no no significant significant slight .sup.15% in dioctyl adipate .sup.2melted at 80 C.

(66) TABLE-US-00002 TABLE 2 Composition (in parts by weight) and properties of Z8 to Z11 and Ref9 to Ref13. Composition Z8 Z9 Z10 Z11 Ref9 Ref10 Ref11 Ref12 Ref13 Polymer P2 80.00 80.00 80.00 80.00 80.00 80.00 80.00 80.00 80.00 Aldimine A1 A4 A6 A7 R1 R2 R3 R4 R5 7.53 7.91 6.97 8.92 7.00 7.17 6.89 7.39 7.78 Salicylic acid 1.50 1.50 1.50 1.50 1.50 1.50 1.50 0.20 0.20 solution.sup.1 Viscosity (1 d RT) 16.3 24.1 24.9 16.5 19.4 27.6 23.7 27.5 27.9 [Pa .Math. s] (7 d 60 C.) 20.6 33.0 38.1 23.1 28.0 45.3 30.0 48.5 50.1 Tack-free time 1 h 35 55 50 50 45 40 2 h 35 1 h 20 63 Tensile strength 0.52 1.05 0.66 0.65 1.22 1.72 1.79 0.66 0.92 [MPa] Elongation at 297 288 241 115 373 346 241 214 211 break [%] Modulus of 0.41 0.98 0.66 0.82 1.68 3.54 4.60 0.69 1.06 elasticity 5% [MPa] Modulus of 0.21 0.57 0.40 0.62 0.74 1.07 1.42 0.44 0.66 elasticity 50% Appearance nice nice nice nice nice nice nice nice nice Odor no no no no no no no no no .sup.15% in dioctyl adipate

(67) TABLE-US-00003 TABLE 3 Composition (in parts by weight) and properties of Z12 to Z15. Composition Z12 Z13 Z14 Z15 Polymer P3 80.00 80.00 80.00 80.00 Aldimine A1 A4 A6 A7 10.47 10.99 9.68 12.39 Salicylic acid 1.50 1.50 1.50 1.50 solution.sup.1 Viscosity (1 d RT) 15.2 14.7 13.4 15.1 [Pa .Math. s] (7 d 60 C.) 17.5 17.5 17.3 17.5 Tack-free time 3 h 2 h 15 2 h 5 1 h 20 Tensile strength 1.42 1.69 0.94 0.94 [MPa] Elongation at 240 263 264 128 break [%] Modulus of 1.72 1.56 0.85 0.90 elasticity 5% [MPa] Modulus of 0.82 0.96 0.52 0.87 elasticity 50% Appearance nice nice nice nice Odor no no no no .sup.15% in dioctyl adipate

(68) Compositions Z16 and Ref14

(69) For each composition, the ingredients specified in table 4 were mixed in the amounts specified (in parts by weight) by means of a centrifugal mixer (SpeedMixer DAC 150, FlackTek Inc.) with exclusion of moisture at 3000 rpm for one minute and stored with exclusion of moisture. Each composition was tested as follows:

(70) As a measure of plasticizer migration, each composition was applied to a cardboard underlayer such that it had a round base area of diameter 12 mm and a height of 20 mm, and was stored under standard climatic conditions for 7 days. Around each composition, thereafter, a dark oval speck had formed on the cardboard. The dimensions thereof (height and width) were measured and reported in table 4 as Migration.

(71) Composition Z16 is an inventive example. Composition Ref14 is a comparative example.

(72) TABLE-US-00004 TABLE 4 Composition (in parts by weight) and properties of Z16 and Ref14. Composition Z16 Ref14 Polymer P4 15.00 15.00 Chalk.sup.1 15.00 15.00 Silica.sup.2 1.13 1.13 Aldimine A1 R4 7.80 7.65 Dibutyltin dilaurate solution.sup.3 1.50 1.50 Salicylic acid solution.sup.4 3.00 3.00 Migration Height 80 110 [mm] Width 55 85 .sup.1ground calcium carbonate coated with fatty acid .sup.2hydrophobically modified fumed silica .sup.35% in diisodecyl phthalate .sup.45% in dioctyl adipate

(73) Compositions Z17 and Ref 15 and Ref16

(74) These compositions were produced in the same way as described for composition Z16 using the figures in table 5.

(75) As a measure of plasticizer migration, each composition was applied to a cardboard underlayer such that it had a round base area of diameter 15 mm and a height of 4 mm, and was stored under standard climatic conditions for 3 months. A dark oval speck formed around each composition on the cardboard, the dimensions of which (height and width) were measured after 7 days and after 3 months under standard climatic conditions and were reported in table 5 as Migration (7 d) or (3 months).

(76) As a measure of the tendency to Stress-cracking on plastic, each composition was applied to a transparent, prestressed plastic sheet of polycarbonate (Makrolon) having the dimensions of 150302 mm so as to give rise to a coating of 30302 mm in the middle of the stressed sheet. After 24 h under standard climatic conditions, the coating or the composition was removed and the sheet was examined for cracking and other visual changes. The prestressed plastic sheet was fixed in each case to a round piece of timber of diameter 12.5 mm mounted on a board such that the long side was at right angles to the round piece of timber and the narrow end was fixed on the board. Low is used to describe the formation of small, slightly visible cracks of length 2 to 3 mm in the edge region of the sheet, which were present only superficially. Significant is used to describe a complete crack across the entire width of the sheet which was visible across the entire thickness of the sheet. In addition, very many small cracks were present here in the edge region of the sheet.

(77) Composition Z17 is an inventive example. Compositions Ref15 to Ref16 are comparative examples.

(78) TABLE-US-00005 TABLE 5 Composition (in parts by weight) and properties of Z17 and Ref15 to Ref16. Composition Z17 Ref15 Ref16 Polymer P4 15.00 15.00 15.00 Chalk 15.00 15.00 15.00 Silica 1.13 1.13 1.13 Aldimine A1 R4 5.57 5.46 Dibutyltin dilaurate solution.sup.1 1.50 1.50 1.50 Salicylic acid solution.sup.2 3.00 3.00 3.00 Migration Height 18 37 17 (7 d) [mm] Width 19 41 17 Migration Height 23 47 25 (3 months) [mm] Width 23 52 25 Stress cracking low significant low .sup.15% in diisodecyl phthalate .sup.25% in dioctyl adipate

(79) It is clear from the migration results in table 5 that the inventive composition Z17 comprising aldimine A1 has a similar or even lower tendency to plasticizer migration compared to the composition Ref16 without aldimine. By contrast, composition Ref15 comprising aldimine R4, which likewise contains a long-chain substituent and has a similarly high molecular weight to aldimine A1, has significant plasticizer migration.