DECORATIVE AND PROTECTIVE COATING COMPOSITION FOR METAL, GLASS AND PLASTICS SUBSTRATES

Abstract

I. an inorganic-organic hybrid material obtained from A1. one or more partially hydrolysed alkoxysilanes of the formula (Ia), (R.sup.1O).sub.nSiR.sup.2.sub.3-nR.sup.3 (Ia) A2. optionally one or more partially hydrolysed alkoxysilanes of the formula (Ib), (R.sup.4O).sub.nSiR.sup.5.sub.4-n (Ib) B1. one or more metal alkoxides of the formula (IIa), Ti(OR.sup.6).sub.4 (IIa) B2. optionally one or more metal alkoxides of the formula (IIb), M.sup.+(4-m)(OR.sup.7).sub.4-m (IIb) wherein the symbols and indices have the definitions specified in the description and wherein the molar ratio of Si in components A1 and A2 to Ti in component B1 is 1-20:1; C. one or more oligomeric or polymeric polyols; D. one or more blocked, optionally modified polyisocyanates; and E. optionally one or more monomers, oligomers and/or polymers which have one or more free epoxy groups; II. optionally one or more colorants and III. optionally one or more adjuvants, is suitable especially for the decorative and protective coating of metal, glass and plastics substrates.

Claims

1. A coating composition comprising I. an inorganic-organic hybrid material obtained from A1. one or more partially hydrolysed alkoxysilanes of the formula (Ia),
(R.sup.1O).sub.nSiR.sup.2.sub.3-nR.sup.3  (Ia) where the symbols and indices have the following definitions: R.sup.1 is C.sub.1-C.sub.6 alkyl or C.sub.1-C.sub.10 aryl, R.sup.2 is C.sub.1-C.sub.4 alkyl, C.sub.2-C.sub.4 alkenyl or C.sub.2-C.sub.4-alkynyl, C.sub.6-C.sub.10 aryl, C.sub.6-C.sub.10 aralkyl or C.sub.6-C.sub.10 alkaryl, R.sup.3 is an epoxy-functional group and n is 1, 2 or 3; A2. optionally one or more partially hydrolysed alkoxysilanes of the formula (Ib),
(R.sup.4O).sub.nSiR.sup.5.sub.4-n  (Ib) where the symbols and indices have the following definitions: R.sup.4 is C.sub.1-C.sub.6 alkyl or C.sub.6-C.sub.10 aryl, R.sup.5 is C.sub.1-C.sub.10 alkyl, C.sub.2-C.sub.4 alkenyl or C.sub.2-C.sub.4 alkynyl, C.sub.6-C.sub.10 aryl, C.sub.6-C.sub.10 aralkyl or C.sub.6-C.sub.10 alkaryl, the stated radicals being optionally substituted by one or more, preferably one, amino group(s), and n is 1, 2, 3 or 4; B1. one or more metal alkoxides of the formula (IIa),
Ti(OR.sup.6).sub.4  (IIa) where the symbols have the following definitions: R.sup.6 is C.sub.1-C.sub.6 alkyl or C.sub.6-C.sub.10 aryl; B2. optionally one or more metal alkoxides of the formula (IIb),
M.sup.+(4-m)(OR.sup.7).sub.4-m  (IIb) where the symbols and indices have the following definitions: M is a metal from main or transition group 3 or 4 with EN<1.5 except for Ti, R.sup.7 is C.sub.1-C.sub.6 alkyl, or C.sub.6-C.sub.10 aryl and m is 0 or 1, preferably 1, where the molar ratio of Si in component A1 and A2 to Ti in component B1 is 1-20:1; C. one or more oligomeric or polymeric polyols; D. one or more blocked, optionally modified polyisocyanates; and E. optionally one or more monomers, oligomers and/or polymers which have one or more, preferably at least two, free epoxy groups; II. optionally one or more colorants and III. optionally one or more adjuvants.

2. The coating composition according to claim 1, comprising a compound (la) for which the symbols and indices in the formula (Ia) have the following definitions: R.sup.1 is C.sub.1-C.sub.4 alkyl, R.sup.3 is 3-glycidyloxypropyl and n is 3, preferably 3-glycidyloxypropyltrimethoxysilane and/or 3-glycidyloxypropyltriethoxysilane.

3. The coating composition according to claim 1, comprising one or more compounds of the formula (Ib) preferably selected from the group consisting of tetraethoxysilane, methyltriethoxysilane, hexyltriethoxysilane, phenyltriethoxysilane, aminopropyltriethoxysilane and mixtures of two or more of the stated compounds.

4. The coating composition according to claim 1, wherein the partial hydrolysis of the compound of the formula (I) took place in an acidic medium, preferably with addition of phosphoric acid.

5. The coating composition according to claim 1, wherein the compound (IIa) is titanium tetra-n-butoxide.

6. The coating composition according to claim 1, wherein the symbols and indices of the formula (IIb) have the following definitions: M is Al, Zr, or B; R.sup.7 is C.sub.1-C.sub.6 alkyl and m is 0 or 1.

7. The coating composition according to claim 1, wherein component E comprises one or more di- or triglycidyl ethers or di- or triglycidyl esters, preferably 4,4′-isopropylidenediphenol diglycidyl ether.

8. The coating composition according to claim 1, wherein component C used comprises a branched polyester polyol.

9. The coating composition according to claim 1, wherein component D used comprises one or more blocked polyisocyanates based on isophorone diisocyanate or hexamethylene diisocyanate.

10. A method for producing a coated substrate, comprising the steps of a) wet-chemically applying a coating composition according to claim 1 to the substrate, and b) thermally curing the coating composition.

11. The method according to claim 10, wherein the curing time is in the range from 2 minutes to 2 hours.

12. The method according to claim 10, wherein the thermal curing in step b) takes place at a temperature in the range from 80 to 240° C.

13. The method according to claim 10, wherein the substrate is a metal, glass and plastics substrate, more particularly an aluminium substrate.

14. A substrate, preferably a metal, glass and plastics substrate, more particularly an aluminium substrate, coated with a coating composition as described in claim 1.

15. (canceled)

Description

EXAMPLES

Example 1

[0194] Basecoat:

[0195] 244 mmol of 3-glycidyloxypropyltriethoxysilane were stirred with 6.60 g of 1M phosphoric acid and cooled to 10° C. Thereafter 50 mmol of orthobutyl titanate (titanium tetra-n-butoxide) were added, after which stirring took place and further cooling to 10° C. The dropwise addition of 220 mmol of water was followed by further stirring.

[0196] Subsequently 500 mmol of propylene glycol monomethyl ether acetate (PGMEA), 191 mmol of branched polyester containing hydroxyl groups (Desmophen D651 MPA/X) and 51 mmol of blocked aliphatic polyisocyanates based on isophorone diisocyanate (Desmodur PL340 BA/SN) were added, with subsequent stirring.

[0197] Production of a Silver-Coloured Paint:

[0198] 244 mmol of 3-glycidyloxypropyltriethoxysilane were stirred with 6.60 g of 1M phosphoric acid and cooled to 10° C. Thereafter 50 mmol of orthobutyl titanate were added, after which stirring took place and further cooling to 10° C. The dropwise addition of 220 mmol of water was followed by further stirring.

[0199] Subsequently 500 mmol of PGMEA, 191 mmol of branched polyester containing hydroxyl groups (Desmophen D651 MPA/X) and 51 mmol of blocked aliphatic polyisocyanates based on isophorone diisocyanate (Desmodur PL340 BA/SN) were added, with subsequent stirring. This was followed by the addition of 100.0 g of PGMEA, 5.0 g of surface additives and rheological additives (Tego Dispers 6700 and Glide 100), 8.3 g of aluminium pigment paste (Hydrolan STAPA S2100), 20.8 g of mother-of-pearl pigment (Magnapearl 3100) and 8.0 g of yellow and white pigment paste, with subsequent stirring.

[0200] The coating composition from Example 1 was applied via spray coating with a robot to unanodized precleaned aluminium components. The film thickness was established at 12 μm. The coating was cured without preliminary drying at a temperature of 160° C. for 60 minutes in a forced air oven. The silver-coloured films obtained meet the desired requirements.

Example 2

[0201] Production of Basecoat:

[0202] 132 mmol of 3-glycidyloxypropyltriethoxysilane were introduced with 101 mmol of methyltrimethoxysilane, 31 mmol of tetraethoxysilane, 39 mmol of phenyltriethoxysilane and 13 mmol of hexyltrimethoxysilane, 5.79 g of 1M phosphoric acid were added, and the mixture was stirred and cooled to 10° C.

[0203] Thereafter 63 mmol of orthobutyl titanate were added, followed by further stirring and additional cooling to 10° C. 463 mmol of water were added dropwise to this mixture, with further stirring. Added subsequently were 624 mmol of PGMEA, 104 mmol of branched polyesters containing hydroxyl groups (Desmophen D651 MPA/X), 28 mmol of blocked aliphatic polyisocyanates based on isophorone diisocyanate (Desmodur PL340 BA/SN), 18 mmol of 4,4′-isopropylidenediphenol diglycidyl ether, 10 mmol of 3-glycidyloxypropyltriethoxysilane and 5 mmol of 3-aminopropyltriethoxysilane, after which the mixture was stirred.

[0204] Production of a Bronze-Coloured Paint:

[0205] 132 mmol of 3-glycidyloxypropyltriethoxysilane were introduced with 101 mmol of methyltrimethoxysilane, 31 mmol of tetraethoxysilane, 39 mmol of phenyltriethoxysilane and 13 mmol of hexyltrimethoxysilane, 5.79 g of 1M phosphoric acid were added, and the mixture was stirred and cooled to 10° C.

[0206] Thereafter 63 mmol of orthobutyl titanate were added, followed by further stirring and additional cooling to 10° C. 463 mmol of water were added dropwise to this mixture, with further stirring. Added subsequently were 624 mmol of PGMEA, 104 mmol of branched polyesters containing hydroxyl groups (Desmophen D651 MPA/X), 28 mmol of blocked aliphatic polyisocyanates based on isophorone diisocyanate (Desmodur PL340 BA/SN), 18 mmol of 4,4′-isopropylidenediphenol diglycidyl ether, 10 mmol of 3-glycidyloxypropyltriethoxysilane and 5 mmol of 3-aminopropyltriethoxysilane, after which the mixture was stirred.

[0207] Added subsequently were 38.0 g of PGMEA, 5.5 g of surface additives and rheological additives (Tego Dispers 6700 and Glide 100), 22.63 g of mica effect pigment (Royal Gold 323), 1.13 g of Carbon Black Pigment (200 PWD), and the mixture was subsequently stirred.

Example 3

[0208] 103 mmol of 3-glycidyloxypropyltriethoxysilane were introduced with 79 mmol of methyltrimethoxysilane, 24 mmol of tetraethoxysilane, 31 mmol of phenyltriethoxysilane and 11 mmol of hexyltrimethoxysilane, 4.53 g of 1M phosphoric acid were added, and the mixture was subsequently stirred and cooled to 10° C.

[0209] Thereafter 49 mmol of orthobutyl titanate were added, with subsequent stirring and further cooling to 10° C. Added dropwise to this mixture were 363 mmol of water, with subsequent stirring. Subsequently 470 mmol of acetone, 282 mmol of isopropylideneglycerol, 54.2 g of branched polyester containing hydroxyl groups (Plusodur V730S), 66 mmol of blocked aliphatic polyisocyanates based on isophorone diisocyanate (Desmodur PL340 BA/SN), 14 mmol of 4,4′-isopropylidenediphenol diglycidyl ether, 8 mmol of 3-glycidyloxypropyltriethoxysilane and 4 mmol of 3-aminopropyltriethoxysilane were added and the mixture was subsequently stirred.

[0210] Production of a High-Gloss Black Paint:

[0211] 103 mmol of 3-glycidyloxypropyltriethoxysilane were introduced with 79 mmol of methyltrimethoxysilane, 24 mmol of tetraethoxysilane, 31 mmol of phenyltriethoxysilane and 11 mmol of hexyltrimethoxysilane, 4.53 g of 1M phosphoric acid were added, and the mixture was subsequently stirred and cooled to 10° C.

[0212] Thereafter 49 mmol of orthobutyl titanate were added, with subsequent stirring and further cooling to 10° C. Added dropwise to this mixture were 363 mmol of water, with subsequent stirring.

[0213] Subsequently 470 mmol of acetone, 282 mmol of isopropylideneglycerol, 54.2 g of branched polyester containing hydroxyl groups (Plusodur V730S), 66 mmol of blocked aliphatic polyisocyanates based on isophorone diisocyanate (Desmodur PL340 BA/SN), 14 mmol of 4,4′-isopropylidenediphenol diglycidyl ether, 8 mmol of 3-glycidyloxypropyltriethoxysilane and 4 mmol of 3-aminopropyltriethoxysilane were added and the mixture was subsequently stirred.

[0214] Added subsequently were 50.0 g of acetone, 69.0 g of isopropylideneglycerol, 4.0 g of surface additives and rheological additives (Tego Dispers 6700 and Glide 100) and also 30.0 g of carbon black pigment paste, and the mixture was subsequently stirred.

Example 4

[0215] 173 mmol of 3-glycidyloxypropyltriethoxysilane were introduced with 133 mmol of methyltrimethoxysilane, 40 mmol of tetraethoxysilane, 51 mmol of phenyltriethoxysilane and 18 mmol of hexyltrimethoxysilane. Added to this were 7.59 g of 1M phosphoric acid, followed by subsequent stirring and cooling to 10° C. Thereafter 82 mmol of orthobutyl titanate were added, with subsequent stirring and further cooling to 10° C. Added dropwise to this mixture were 606 mmol of water, with subsequent stirring.

[0216] Added subsequently were 434 mmol of PGMEA, 19.33 g of trifunctional polypropylene ether polyol (Desmophen D1380BT), 28 mmol of blocked aliphatic polyisocyanates based on isophorone diisocyanate (Desmodur PL340 BA/SN), 24 mmol of 4,4′-isopropylidenediphenol diglycidyl ether, 14 mmol of 3-glycidyloxypropyltriethoxysilane and 7 mmol of 3-aminopropyltriethoxysilanes, with subsequent stirring.