ALKOXYSILANE- AND ALLOPHANATE-FUNCTIONALIZED COATING MATERIALS

Abstract

An alkoxysilane-functionalized and allophanate-functionalized coating material including a) a binder component of 10-99 wt % of at least one reaction product of I. and II. wherein I includes A) at least one alkoxysilane-containing monourethane A) of the formula 1 R.sub.n(OR.sub.1).sub.3-nSi—R.sup.2—NH—(C═O)—OR.sup.3 wherein R, R.sup.1, R.sup.2 and R.sup.3 represent hydrocarbon radicals having 1-8 carbon atoms, and n represents 0-2, and B) at least one diisocyanate B), and II includes the subsequent reaction of C) with at least one diol and/or polyol C), in a ratio of NCO groups of reaction product I to OH groups of the diol and/or polyol II. C) of 1.0:1.5 to 1.0:0.6; b) 1-90 wt % of at least one further binder component distinct from a) a hydroxyl-containing or amino-containing binder component, c) 0-50 wt % of at least one polyisocyanate having an NCO functionality of at least 2, d) 0-5 wt % of at least one catalyst, wherein components a)-d) add up to 100 wt %.

Claims

1. An alkoxysilane-functionalized and allophanate-functionalized coating material comprising a) a binder component of 10-99 wt % of at least one reaction product of I. A) at least one alkoxysilane-containing monourethane A) of the formula 1
R.sub.n(OR.sup.1).sub.3-nSi—R.sup.2—NH—(C═O)—OR.sup.3   formula 1 wherein R, R.sup.1, R.sup.2 and R.sup.3 independently of one another represent hydrocarbon radicals having 1-8 carbon atoms, wherein these may be linear, branched or cyclic or else may be integrated together to form a cyclic system, and n represents 0-2, and B) at least one diisocyanate B), optionally in the presence of at least one catalyst K), in a molar ratio of A) to B) of from 1.0:1.5 to 1.0:0.6, II. and subsequent reaction of C) with at least one diol and/or polyol C), optionally in the presence of at least one catalyst K), in a ratio of NCO groups of reaction product I. to OH groups of the diol and/or polyol II. C) of from 1.0:1.5 to 1.0:0.6; b) from 1-90 wt % of at least one further binder component distinct from the binder component a), a hydroxyl-containing or amino-containing binder component, c) from 0-50 wt % of at least one aromatic, aliphatic or cycloaliphatic polyisocyanate having an NCO functionality of at least 2, d) from 0-5 wt % of at least one catalyst, wherein components a)-d) add up to 100 wt %, e) optionally auxiliaries and/or additives, f) optionally solvents.

2. An alkoxysilane-functionalized and allophanate-functionalized coating material consisting of a) a binder component of from 10-99 wt % of at least one reaction product of I. A) at least one alkoxysilane-containing monourethane A) of the formula 1
R.sub.n(OR.sup.1).sub.3-nSi—R.sup.2—NH—(C═O)—OR.sup.3   formula 1 wherein R, R.sup.1, R.sup.2 and R.sup.3 independently of one another represent hydrocarbon radicals having 1-8 carbon atoms, wherein these may be linear, branched or cyclic or else may be integrated together to form a cyclic system, and n represents 0-2, and B) at least one diisocyanate B), optionally in the presence of at least one catalyst K), in a molar ratio of A) to B) of 1.0:1.5 to 1.0:0.6; II. and subsequent reaction C) with at least one diol and/or polyol C), optionally in the presence of at least one catalyst K), in a ratio of NCO groups of reaction product I. to OH groups of the diol and/or polyol II. C) of from 1.0:1.5 to 1.0:0.6; b) from 1-90 wt % of at least one further binder component distinct from the binder component a), preferably of a hydroxyl-containing or amino-containing binder component, c) from 0-50 wt % of at least one aromatic, aliphatic or cycloaliphatic polyisocyanate having an NCO functionality of at least 2, d) from 0-5 wt % of at least one catalyst, wherein components a)-d) add up to 100 wt %, e) optionally auxiliaries and/or additives, f) optionally solvents.

3. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein R, R.sup.1, R.sup.2 and R.sup.3 simultaneously or independently of one another represent methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl or tert-butyl.

4. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein it has n equal to 0, R.sup.1 and R.sup.3 simultaneously or independently of one another equal to methyl or ethyl and R.sup.2 simultaneously or independently of one another equal to methyl or propyl.

5. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein it has n equal to 0 and R.sup.2 equal to methyl or propyl, and R.sup.1 equal to methyl or ethyl and R.sup.3═R.sup.1.

6. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein it has n equal to 0, R.sup.1 and R.sup.3 equal to methyl and R.sup.2 equal to propyl.

7. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the diisocyanate B) is selected from isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), 2,2′-dicyclohexylmethane diisocyanate (2,2′-H12MDI), 2,4′-dicyclohexylmethane diisocyanate (2,4′-H12MDI), 4,4′-dicyclohexylmethane diisocyanate (4,4′-H12MDI), 2-methylpentane diisocyanate (MPDI), pentane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (2,2,4-TMDI), 2,4,4-trimethylhexamethylene diisocyanate (2,4,4-TMDI), norbornane diisocyanate (NBDI), methylenediphenyl diisocyanate (MDI), toluidine diisocyanate (TDI), tetramethylxylylene diisocyanate (TMXDI), xylylene diisocyanate (MXDI), individually or in admixture.

8. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the diol and/or polyol C) is selected from ethylene glycol, propane-1,2-diol, propane-1,3-diol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, butane-1,2-diol, butane-1,4-diol, butylethylpropane-1,3-diol, methylpropane-1,3-diol, pentane-1,5-diol, bis(1,4-hydroxymethyl)cyclohexane (cyclohexanedimethanol), glycerol, hexanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol, bisphenol A, bisphenol B, bisphenol C, bisphenol F, norbornylene glycol, 1,4-benzyldimethanol, 1,4-benzyldiethanol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 1,4-butylene glycol, 2,3-butylene glycol, di-β-hydroxyethylbutanediol, pentane-1,5-diol, hexane-1,6-diol, octane-1,8-diol, decanediol, dodecanediol, neopentyl glycol, cyclohexanediol, 3(4),8(9)-bis(hydroxymethyl)tricyclo[5.2.1.0.sup.2,6]decane (dicidol), 2,2-bis(4-hydroxycyclohexyl)propane, 2,2-bis[4-(β-hydroxyethoxy)phenyl]propane, 2-methylpropane-1,3-diol, 2-methylpentane-1,5-diol, 2,2,4(2,4,4)-trimethylhexane-1,6-diol, hexane-1,2,6-triol, butane-1,2,4-triol, tris(β-hydroxyethyl) isocyanurate, mannitol, sorbitol, polypropylene glycols, polybutylene glycols, xylylene glycol or neopentyl glycol hydroxypivalate, alone or in admixture.

9. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the diol and/or polyol C) is selected from ethylene glycol, triethylene glycol, butane-1,4-diol, propane-1,2-diol, pentane-1,5-diol, hexane-1,6-diol, cyclohexanedimethanol, decanediol, dodecane-1,12-diol, 2,2,4-trimethylhexane-1,6-diol, 2,4,4-trimethylhexane-1,6-diol, 2,2-dimethylbutane-1,3-diol, 2-methylpentane-2,4-diol, 3-methylpentane-2,4-diol, 2,2,4-trimethylpentane-1,3-diol, 2-ethylhexane-1,3-diol, 2,2-dimethylhexane-1,3-diol, 3-methylpentane-1,5-diol, 2-methylpentane-1,5-diol, trimethylolpropane, 2,2-dimethylpropane-1,3-diol (neopentyl glycol), neopentyl glycol hydroxypivalate and cis/trans-cyclohexane-1,4-diol, alone or in admixture.

10. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the diol and/or polyol C) is selected from pentane-1,5-diol, hexane-1,6-diol, dodecane-1,12-diol, 2,2,4-trimethylhexane-1,6-diol, 2,4,4-trimethylhexane-1,6-diol, 2,2-dimethylbutane-1,3-diol, 2-methylpentane-2,4-diol, 3-methylpentane-2,4-diol, 2,2,4-trimethylpentane-1,3-diol, 2-ethylhexane-1,3-diol, 2,2-dimethylhexane-1,3-diol, 3-methylpentane-1,5-diol, 2-methylpentane-1,5-diol, 2,2-dimethylpropane-1,3-diol (neopentyl glycol) and cis/trans-cyclohexane-1,4-diol, alone or in admixture.

11. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the diol and/or polyol C) is selected from hydroxyl-containing polyesters, polyethers, polyacrylates, polycarbonates and polyurethanes having an OH number of from 20 to 500 mg KOH/g and an average molar mass of from 250 to 6000 g/mol, alone or in admixture.

12. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the diol and/or polyol C) is selected from hydroxyl-containing polyesters or polyacrylates having an OH number of from 50 to 250 mg KOH/g and an average molecular weight of from 500 to 6000 g/mol, alone or in admixture.

13. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one catalyst K) is selected from the group consisting of metal carboxylates, tert-amines, amidine, guanidine, quaternary ammonium salts, tetraalkylammonium salts, quaternary phosphonium salts, metal acetylacetonates, quaternary ammonium acetylacetonates, quaternary phosphonium acetylacetonates, carboxylic acids, aluminium alkoxides, zirconium alkoxides, titanium alkoxides and/or boron alkoxides and/or esters thereof, phosphorus- and nitrogen-containing catalysts, sulphonic acids, alone or in admixture.

14. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one catalyst K) is zinc acetylacetonate and/or zinc ethylhexanoate.

15. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein a hydroxyl-containing and/or amino-containing binder is employed as the at least one further binder component b).

16. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one further binder component b) is selected from hydroxyl-containing polyesters, polyethers, polyacrylates, polycarbonates and polyurethanes having an OH number of from 20 to 500 mg KOH/g and an average molar mass of from 250 to 6000 g/mol, alone or in admixture.

17. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one further binder component b) is selected from hydroxyl-containing polyesters or polyacrylates having an OH number of from 50 to 250 mg KOH/g and an average molecular weight of from 500 to 6000 g/mol, alone or in admixture.

18. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one further binder component b) is at least one adduct of an isocyanatotrialkoxysilane and a mono- or polyhydric alcohol.

19. The alkoxysilane-functionalized and allophanate-functionalized coating materials according to claim 1, wherein at least one derivative of hydroxyl-containing polyethers, polyesters, polycarbonatediols or polyacrylates with isocyanatopropyltrialkoxysilane, alone or in mixtures, is present as the at least one further binder component b).

20. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one further binder component b) is aminopropyltriethoxysilane, aminomethyltrimethoxysilane or aminomethyltriethoxysilane, alone or in admixture.

21. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein component c) is a polyisocyanate selected from isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), 2,2′-dicyclohexylmethane diisocyanate (2,2′-H12MDI), 2,4′-dicyclohexylmethane diisocyanate (2,4′-H12MDI), 4,4′-dicyclohexylmethane diisocyanate (4,4′-H12MDI), 2-methylpentane diisocyanate (MPDI), pentane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (2,2,4-TMDI), 2,4,4-trimethylhexamethylene diisocyanate (2,4,4-TMDI), norbornane diisocyanate (NBDI), methylenediphenyl diisocyanate (MDI), toluidine diisocyanate (TDI), tetramethylxylylene diisocyanate (TMXDI), xylylene diisocyanate (MXDI), individually or in admixture.

22. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein component c) is an isocyanurate, in particular of IPDI and/or HDI.

23. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one catalyst d) is selected from the group consisting of metal carboxylates, tert-amines, amidine, guanidine, quaternary ammonium salts, tetraalkylammonium salts, quaternary phosphonium salts, metal acetylacetonates, quaternary ammonium acetylacetonates, quaternary phosphonium acetylacetonates, carboxylic acids, aluminium alkoxides, zirconium alkoxides, titanium alkoxides and/or boron alkoxides and/or esters thereof, phosphorus- and nitrogen-containing catalysts, sulphonic acids, alone or in admixture.

24. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein the at least one catalyst d) is selected from tetraethylammonium benzoate, tetrabutylammonium hydroxide, tetraethylammonium acetylacetonate, tetrabutylammonium acetylacetonate, dibutyltin dilaurate, zinc acetylacetonate, zinc ethylhexanoate.

25. The alkoxysilane-functionalized and allophanate-functionalized coating material according to claim 1, wherein solvents, stabilizers, light stabilizers, additional crosslinkers, fillers, pigments, flow control agents or rheological assistants, alone or in admixture, are employed as auxiliaries and/or additives e).

26. Compositions including paint compositions, adhesive compositions, sealant compositions and metal-coating compositions wherein the compositions comprise the alkoxysilane-functionalized, allophanate-containing coating materials according to claim 1.

Description

EXAMPLES

[0142] Input Materials:

[0143] Vestanat® EP-UPMS: trimethoxysilylpropyl methylcarbamate (Evonik Resource Efficiency GmbH) Vestanat® IPDI: isophorone diisocyanate (Evonik Resource Efficiency GmbH)

[0144] Vestanat® TMDI: mixture of 2,2,4-trimethylhexamethylene diisocyanate (2,2,4-TMDI) and 2,4,4-trimethylhexamethylene diisocyanate (Evonik Resource Efficiency GmbH)

[0145] Vestanat® HT 2500/100: hexamethylene 1,6-diisocyanate, homopolymeric (isocyanurate type) (Evonik Resource Efficiency GmbH)

[0146] Vestanat® EP Cat 11 B: tetraethylammonium benzoate in butanol (Evonik Resource Efficiency GmbH)

[0147] Tegoglide® 410: slip and antiblocking additive based on a polyether siloxane copolymer (Evonik Resource Efficiency GmbH)

[0148] Vestanat® EP-M60: linear, short-chain silane-functionalized crosslinker (Evonik Resource Efficiency GmbH)

[0149] Vestanat® EP-M95: branched, short-chain silane-functionalized crosslinker (Evonik Resource Efficiency GmbH)

[0150] Vestanat® EP-M120: linear, long-chain silane-functionalized crosslinker (Evonik Resource Efficiency GmbH)

[0151] Setalux® 1760 VB-64: polyacrylate polyol, Nuplex Resins B.V.

[0152] Tinuvin® 292: sterically hindered amine, light stabilizer; BASF SE

[0153] Tinuvin® 900: UV absorber; BASF SE

[0154] 1. Production of a)

[0155] Alkoxysilane- and Allophanate-Functionalized Urethane 1

[0156] 36.9 g of Vestanat® EP-UPMS, 0.04 g of zinc(II) ethylhexanoate and 34.7 g of Vestanat® IPDI were charged to a three-necked flask fitted with a reflux condenser, blanketed with nitrogen and heated with stirring to 100° C. After heating for 12 hours, an NCO content of 9.33% was obtained. The obtained allophanate was cooled, admixed with 8.37 g of pentanediol and 0.01% DBTL and stirred at 60-65° C. for 17 h until an NCO content of <0.1% was achieved and, after about 3 h, 20 g of butyl acetate were added for viscosity reduction. The alkoxysilane- and allophanate-funcionalized urethane 1 thus obtained is a clear liquid having a viscosity of 3457 mPas (at 23° C.).

[0157] Alkoxysilane- and Allophanate-Functionalized Urethane 2

[0158] 31.7 g of Vestanat® EP-UPMS, 0.04 g of zinc(II) ethylhexanoate and 29.8 g of Vestanat® IPDI were charged to a three-necked flask fitted with a reflux condenser, blanketed with nitrogen and heated with stirring to 100° C. After heating for 6 hours, an NCO content of 9.12% was obtained. The resulting allophanate was cooled, admixed with 13.5 g of dodecanediol and 0.01% DBTL and stirred at 60-65° C. for several hours until an NCO content of <0.1% was achieved and then, while still hot, 20 g of 1-MOP acetate were added for viscosity reduction. The alkoxysilane- and allophanate-funcionalized urethane 2 thus obtained is a clear liquid having a viscosity of 1902 mPas (at 23° C.).

[0159] 2. Preparation of Clearcoats from the Alkoxysilane-Functionalized and Allophanate-Functionalized Coating Materials

[0160] For the formulation of the inventive clearcoats and of the comparative examples the components of the compositions represented in Table 1 were mixed with one another immediately prior to processing.

[0161] The viscosity of the formulations, determined as the flow time in the DIN 4 cup at 23° C., was approximately 20 seconds.

TABLE-US-00001 TABLE 1 Composition of the inventive clearcoats and comparative examples III IV Item I II Comparative Comparative V Comparative 1 Alkoxysilane- and allophanate-functionalized 28.78 urethane 1 2 Alkoxysilane- and allophanate-functionalized 31.40 urethane 2 3 Comparative example: Vestanat ® EP-M95 26.79 4 Comparative example: Vestanat ® EP-M60 26 5 Comparative example: Vestanat ® EP-M120 53.2 6 Setalux ® 1760 VB-64 (64% strength) 35.97 37.25 41.85 40.6 41.6 7 EP-CAT 11 B 0.92 0.95 1.06 1.0 1.1 8 TegoGlide 410 (10% in butyl acetate) 0.50 0.49 0.48 0.49 0.5 9 Tinuvin 292 0.23 0.24 0.27 0.26 0.27 10 Tinuvin 900 (8% in xylene) 2.88 2.98 3.34 3.25 3.33 11 Butyl acetate/xylene (1:1) 30.72 28.28 26.21 28.4 0

[0162] Table 2 reports the potlives of compositions I-VI. The potlives were determined as follows: The liquid sample for determination (at least 70 ml) is introduced into a 100 ml glass vial and provided vertically with a metal pin; hanging at the end of the pin immersed in the sample is a circular metal plaque having a diameter of approximately 2 cm. The glass vial is provided with a perforated lid and the metal pin is clamped into the gelation time instrument (Techne Gelation Timer). The sample is now in a water tank set at room temperature (23° C.) (Lauda thermostat model BK2). The metal pin in the sample moves up and down in oscillation at a constant rhythm until the resistance of the sample is greater than the force of the gelation time instrument. In this case, the metal pin comes to a standstill; the sample is “gelled”. The time which elapses between the start of the oscillating movement of the metal pin and the end thereof is reported on the display of the gelation instrument.

TABLE-US-00002 TABLE 2 Potlives of compositions I-V Clearcoat system Potlife (h) I 19.5 II 20.8 III (Comparative example) 4.3 IV (Comparative example) 4.0 V (Comparative example) 2.0

[0163] From the potlives set out in Table 2 it is clearly evident that the inventive alkoxysilane- and allophanate-functionalized coating materials I and II have a markedly longer potlife than the Comparative Examples III-V. From the prior art (Comparative Examples III-V) there was no expectation that the potlife of the inventive alkoxysilane- and allophanate-functionalized coating materials I and II, which comprise the inventive alkoxysilane- and allophanate-functionalized urethanes 1-2, would be prolonged many times over.

[0164] Curing of the Clearcoats

[0165] To determine the mechanical characteristics, all paints were applied to phosphatized steel sheets (Chemetall Gardobond 26S/60/OC) with a 120 μm doctor blade and cured for 22 minutes at 160° C.

TABLE-US-00003 TABLE 3 Coat properties of the inventive alkoxysilane- and allophanate-functionalized coating materials I-III after curing at 160° C. (22 min) Composition I II III Pendulum hardness (König) [s] 182 202 147 after 1 d Erichsen cupping [mm] 6.0 6.5 4.5 (EN ISO 1520) MEK test [ASTM D 4752] >150 >150 >150 (Double rubs, 1 kg applied weight)

[0166] The coat properties of the coatings obtained using the inventive alkoxysilane- and allophanate-functionalized coating materials I and II show a high pendulum hardness compared to comparative example III coupled with exceptionally high flexibility and good MEK resistance.