Dimer fatty acid/polyesterdiol reaction product and use thereof in coating materials

Abstract

A pigmented aqueous basecoat material that includes a dimer fatty acid/polyesterdiol reaction product which is preparable by reacting (a) dimer fatty acids with (b) at least one polyesterdiol of the general structural formula (I) ##STR00001##
where: R is a divalent radical including 2-10 carbon atoms; R.sup.1 and R.sup.2 are independently straight-chain or branched alkylene radicals having 2-10 carbon atoms; X and Y are independently O, S or NR.sup.3, where R.sup.3 is hydrogen or an alkyl radical having 1-6 carbon atoms; and m and n are selected accordingly such that the polyesterdiol possesses a number-average molecular weight of 450-2200 g/mol, components (a) and (b) are used in a molar ratio of 0.7/2.3 to 1.3/1.7, and the resulting dimer fatty acid/polyesterdiol reaction product possesses a number-average molecular weight of 1200-5000 g/mol and an acid number <10 mg KOH/g.

Claims

1. A pigmented aqueous basecoat material, comprising: a solvent comprising water and an organic solvent; and a dimer fatty acid/polyesterdiol reaction product comprising, in reacted form: (a) dimer fatty acids; (b) a polyesterdiol of formula (I): ##STR00004## wherein: R is a divalent organic radical comprising 2 to 10 carbon atoms; R.sup.1 and R.sup.2 are each independently straight-chain or branched alkylene radicals having 2 to 10 carbon atoms; X and Y are each independently O, S, or NR.sup.3, where R.sup.3 is hydrogen or an alkyl radical having 1 to 6 carbon atoms; and m and n are selected accordingly such that the polyesterdiol possesses a number-average molecular weight of 450 to 2200 g/mol, wherein components (a) and (b) are reacted in a molar ratio of 0.7/2.3 to 1.3/1.7 and the resulting dimer fatty acid/polyesterdiol reaction product possesses a number-average molecular weight of 1200 to 5000 g/mol and an acid number <10 mg KOH/g.

2. The pigmented aqueous basecoat material of claim 1, wherein the wherein the dimer fatty acids consist of at least 90 wt % of dimeric molecules, less than 5 wt % of trimeric molecules, and less than 5 wt % of monomeric molecules and of other byproducts.

3. The pigmented aqueous basecoat material of claim 1, wherein the dimer fatty acids are prepared from linolenic, linoleic and/or oleic acid and consist of 98 wt % of dimeric molecules, 1.5 wt % of trimeric molecules, and 0.5 wt % of monomeric molecules and of other byproducts.

4. The pigmented aqueous basecoat material of claim 1, wherein, in formula (I): R is a divalent aliphatic radical comprising 2 to 6 carbon atoms; R.sup.1 and R.sup.2 are each independently straight-chain or branched alkylene radicals having 5 and/or 6 carbon atoms; X and Y are each independently O or NH; and m and n are selected accordingly such that the polyesterdiol possesses a number-average molecular weight of 500 to 1400 g/mol.

5. The pigmented aqueous basecoat material of claim 1, wherein components (a) and (b) are reacted in a molar ratio of 0.9/2.1 to 1.1/1.9.

6. The pigmented aqueous basecoat material of claim 1, wherein the dimer fatty acid/polyesterdiol reaction product possesses a number-average molecular weight of 1200 to 4500 g/mol.

7. The pigmented aqueous basecoat material of claim 1, wherein the dimer fatty acid/polyesterdiol reaction product possesses an acid number of <5 mg KOH/g.

8. The pigmented aqueous basecoat material of claim 1, wherein the dimer fatty acid/polyesterdiol reaction product consists of, in reacted form: (a) the dimer fatty acids (a); and (b) at least one polyesterdiol of formula (I).

9. The pigmented aqueous basecoat material of claim 1, wherein a sum total of the weight-percentage fractions of all dimer fatty acid/polyesterdiol reaction products, based on the total weight of the pigmented aqueous basecoat material, is from 0.1 to 30 wt %.

10. The pigmented aqueous basecoat material of claim 1, wherein a sum total of the weight-percentage fractions of all dimer fatty acid/polyesterdiol reaction products, based on the total weight of the pigmented aqueous basecoat material, is from 1 to 20 wt %.

11. The pigmented aqueous basecoat material of claim 1, wherein a sum total of the weight-percentage fractions of all pigments, based on the total weight of the pigmented aqueous basecoat material, is from 1 to 40 wt %.

12. The pigmented aqueous basecoat material of claim 1, wherein a sum total of the weight-percentage fractions of all pigments, based on the total weight of the pigmented aqueous basecoat material, is from 2 to 30 wt %.

13. The pigmented aqueous basecoat material of claim 1, further comprising, as a further binder, at least one polyurethane resin.

14. The pigmented aqueous basecoat material of claim 13, further comprising, as crosslinking agent, an aminoplast resin.

15. The pigmented aqueous basecoat material of claim 13, further comprising, as crosslinking agent, a blocked or nonblocked polyisocyanate.

16. The pigmented aqueous basecoat material of claim 1, wherein the water is present in an amount of at least 40 wt %, based on a total amount of solvents present.

17. The pigmented aqueous basecoat material of claim 1, wherein the water is present in an amount from 50-80 wt %, based on a total amount of solvents present.

18. A method for producing a multiple-coat paint system, the method comprising: (1) applying the pigmented aqueous basecoat material of claim 1 to a substrate; (2)forming a polymer film from the pigmented aqueous basecoat material applied in stage (1), to obtain a basecoat film; (3) applying a clearcoat material to the basecoat film; and subsequently, (4) curing the basecoat film and the clearcoat film together.

19. The method of claim 18, wherein the substrate from stage (1) is a multicoat paint system which possesses defects.

Description

EXAMPLES

(1) The dimer fatty acid used contains less than 1.5 wt % of trimeric molecules, 98 wt % of dimeric molecules, and less then 0.3 wt % of fatty acid (monomer), and is prepared on the basis of linolenic, linoleic, and oleic acid.

(2) Polyester 1 (P1):

(3) Prepared as per example D, column 16, lines 37 to 59 of DE 4009858 A. The corresponding polyester dispersion has a solids content of 60 wt %, the solvent used being butyl glycol instead of butanol.

(4) Inventive Dimer Fatty Acid/Polyesterdiol Reaction Product 1 (DP1):

(5) In a 4 l stainless steel reactor equipped with anchor stirrer, thermometer, column, thermometer for overhead temperature measurement, condenser, and water separator, 1100 g of linear polycaprolactonediol (Capromer PD4-05 (PolyCLO DEG550), from BASF SE), 579.3 g of dimer fatty acid (1 mol) (Pripol 1012, from Croda) and 13.6 g of xylene were heated to 100 C. in the presence of 1.3 g of di-n-butyltin oxide (Axion CS 2455, from Chemtura). Heating was continued slowly until the onset of the condensation. Heating was then continued in steps to 210 C., with a maximum overhead temperature of 85 C., and water was removed. The progress of the reaction was monitored via determination of the acid number. When an acid number of <1.5 mg KOH/g was reached, any xylene still present was removed by vacuum distillation. This gave a reaction product which is solid at room temperature. Gas chromatography found a xylene content of less than 0.1%. Amount of condensate (water): 36.2 g Acid number: 0.1 mg KOH/g Solids content (GC): 100.0% M.sub.n (number-average molar mass (vapor pressure osmosis)): 1450 g/mol Viscosity (resin:xylene=2:1): 168 mPas, (measured at 23 C. using a rotational viscometer from Brookfield, CAP 2000+, spindle 3, shear rate: 13 333 s.sup.1)
Inventive Dimer Fatty Acid/Polyesterdiol Reaction Product 2 (DP2):

(6) In a 4 l stainless steel reactor equipped with anchor stirrer, thermometer, column, thermometer for overhead temperature measurement, condenser, and water separator, 215.7 g of diethylene glycol (from BASF SE), 1784.3 g of epsilon-caprolactone (from BASF SE), and 32.9 g of Octa Soligen Zinn 28 (stabilized tin octanoate, tin content: 28.0%) (from Borchers) were heated to 150 C. and held at this temperature for 5 hours. Subsequently, with simultaneous cooling, xylene was added to the resulting linear polycaprolactonediol 1000 until the theoretical solids fraction was approximately 80%. An OH number of 111.2 mg KOH/g solids fraction (theoretical: 112.2 mg KOH/g solids fraction) was found.

(7) The solution of the polycaprolactonediol 1000 was cooled further to 50 C., at which temperature 579.3 g of dimer fatty acid (1 mol) (Pripol 1012, from Croda) and 2.1 g of di-n-butyltin oxide (Axion CS 2455, from Chemtura) were added. Further heating then took place slowly until the onset of the condensation, with xylene and water being removed by distillation until only a small fraction of 21 g of xylene remained. Further heating then took place in steps to 210 C., with a maximum overhead temperature of 85 C., and water was removed. The progress of the reaction was monitored via determination of the acid number. When an acid number of <1.5 mg KOH/g was reached, any xylene still present was distilled off under vacuum. This gave a reaction product which is solid at room temperature.

(8) Gas chromatography found a xylene content of less than 0.1%. Amount of condensate (water): 37.0 g Acid number: 0.2 mg KOH/g Solids content (GC): 100.0% M.sub.n (number-average molar mass (vapor pressure osmosis)): 2400 g/mol Viscosity (resin:xylene=2:1): 354 mPas, (measured at 23 C. with a rotational viscometer from Brookfield, CAP 2000+, spindle 3, shear rate: 13 333 s.sup.1)
Inventive Dimer Fatty Acid/Polyesterdiol Reaction Product 3 (DP3):

(9) In a 4 l stainless steel reactor equipped with anchor stirrer, thermometer, column, thermometer for overhead temperature measurement, condenser, and water separator, 138.9 g of diethylene glycol (from BASF SE), 2458.5 g of epsilon-caprolactone (from BASF SE), and 21.2 g of Octa Soligen Zinn 28 (stabilized tin octanoate, tin content: 28.0%) (from Borchers) were heated to 150 C. and held at this temperature for 5 hours. Subsequently, with simultaneous cooling, xylene was added to the resulting linear polycaprolactonediol 2000 until the theoretical solids fraction was approximately 80%. An OH number of 55.8 mg KOH/g solids fraction (theoretical: 56.1 mg KOH/g solids fraction) was found.

(10) The solution of the polycaprolactonediol 2000 was cooled further to 50 C., at which temperature 376.2 g of dimer fatty acid (0.649 mol) (Pripol 1012, from Croda) and 2.4 g of di-n-butyltin oxide (Axion CS 2455, from Chemtura) were added. Heating then took place slowly until the onset of the condensation, with xylene and water being removed by distillation until only a small fraction of 24 g of xylene remained. Further heating then took place in steps to 210 C., with a maximum overhead temperature of 85 C., and water was removed. The progress of the reaction was monitored via determination of the acid number. When an acid number of <1.5 mg KOH/g was reached, any xylene still present was distilled off under vacuum. This gave a reaction product which is solid at room temperature.

(11) Gas chromatography found a xylene content of less than 0.1%. . Amount of condensate (water): 23.8 g Acid number: 0.4 mg KOH/g Solids content (GC): 100.0% M.sub.n (number-average molar mass (vapor pressure osmosis)): 4450 g/mol Viscosity (resin: xylene=2:1): 604 mPas, (measured at 23 C. with a rotational viscometer from Brookfield, CAP 2000+, spindle 3, shear rate: 13 333 s.sup.1)
Examples of Paint Formulations
1. Preparation of a Silver Waterborne Basecoat Material 1

(12) The components listed under aqueous phase in table A were stirred together in the order stated to form an aqueous mixture. In the next step an organic mixture was prepared from the components listed under organic phase. The organic mixture was added to the aqueous mixture. The combined mixture was then stirred for 10 minutes and adjusted, using deionized water and dimethylethanolamine, to a pH of 8 and to a spray viscosity of 58 mPas under a shearing load of 1000 s.sup.1 as measured with a rotary viscometer (Rheomat RM 180 instrument from Mettler-Toledo) at 23 C.

(13) TABLE-US-00001 TABLE A Parts by Component weight Aqueous phase 3% strength Na-Mg phyllosilicate 26 solution Deionized water 13.6 Butyl glycol 2.8 Polyurethane-modified polyacrylate; 4.5 prepared as per page 7, line 55 to page 8, line 23 of DE 4437535 A 50% strength by weight solution of 0.6 DSX 1550 (BASF), rheological agent P1 3.2 Tetramethyldecynediol 0.3 (surfactant from BASF) Melamine-formaldehyde resin 4.1 (Cymel 203 from Cytec) 10% strength dimethylethanolamine in 0.3 water Polyurethane-based graft copolymer; 20.4 prepared as per page 19, line 44 to page 20, line 21 of DE 19948004 A Tetramethyldecynediol 1.6 (surfactant from BASF) 3% strength by weight aqueous Viscalex 3.9 HV 30 solution; rheological agent, available from BASF Organic phase Mixture of two commercial aluminum 6.2 pigments, available from Altana-Eckart Butyl glycol 7.5 P1 5
Waterborne Basecoat Material E1:

(14) To prepare the inventive waterborne basecoat material E1, a paint was prepared in the same way as for the preparation of the waterborne basecoat material 1, using DP1 instead of polyester P1 both in the aqueous phase and in the organic phase. DP1 of the organic phase was first dissolved in a third of the amount of butyl glycol present in the organic phase. Additionally 0.984 part by weight of butyl glycol was added to the organic phase to balance out the solvent content of the organic phase. DP1 of the aqueous phase was dissolved in 0.64 part by weight of butyl glycol, thereby also balancing out the solvent content of the aqueous phase.

(15) Waterborne Basecoat Material E2:

(16) To prepare the inventive waterborne basecoat material E2, a paint was prepared in the same way as for the preparation of the waterborne basecoat material 1, using DP2 instead of polyester P1 both in the aqueous phase and in the organic phase. DP2 was first dissolved in a third of the amount of butyl glycol present in the organic phase. Additionally 0.984 part by weight of butyl glycol was added to balance out the solvent content of the organic phase. DP2 of the aqueous phase was dissolved in 0.64 part by weight of butyl glycol, thereby also balancing out the solvent content of the aqueous phase.

(17) Waterborne Basecoat Material E3:

(18) To prepare the inventive waterborne basecoat material E3, a paint was prepared in the same way as for the preparation of the waterborne basecoat material 1, using DP3 instead of polyester P1 both in the aqueous phase and in the organic phase. DP3 was first dissolved in a third of the amount of butyl glycol present in the organic phase. Additionally 0.984 part by weight of butyl glycol was added to balance out the solvent content of the organic phase. DP3 of the aqueous phase was dissolved in 0.64 part by weight of butyl glycol, thereby also balancing out the solvent content of the aqueous phase.

(19) TABLE-US-00002 TABLE 1 Compositions of waterborne basecoat materials 1 and E1 to E3 WBM [wt %] polymer solids 1 4.92 P1 E1 4.92 DP1 E2 4.92 DP2 E3 4.92 DP3

(20) The weight percentage figures in table 1 are based on the overall weight of the waterborne basecoat material.

(21) Comparison Between Eaterborne Basecoat Materials 1 and E1 to E3

(22) To determine the stability with respect to the occurrence of blisters and swelling after condensation-water storage, the multicoat paint systems were produced in accordance with the following general protocol:

(23) A steel panel coated with a standard cathodic electrocoat (Cathoguard 800 from BASF Coatings GmbH) and with dimensions of 1020 cm was coated with a standard surfacer (ALG 670173surfacer, medium-gray, from Hemmelrath). After preliminary drying of the aqueous surfacer at 80 C. over a period of 10 minutes, the surfacer was baked at a temperature of 190 C. over a period of 30 minutes.

(24) The respective waterborne basecoat material from table 1 was then applied pneumatically. The resulting waterborne basecoat film was flashed at room temperature for 2 minutes and subsequently dried in a forced-air oven at 70 C. for 10 minutes. A customary two-component clearcoat material (Progloss 345 from BASF Coatings GmbH) was applied to the dried waterborne basecoat film. The resulting clearcoat film was flashed at room temperature for 20 minutes. The waterborne basecoat film and the clearcoat film were then cured in a forced-air oven at 160 C. for 30 minutes. The present system represents an overbaked original system and will be referred to below as the original finish.

(25) This original finish is abraded with abrasive paper and then the respective waterborne basecoat material from table 1 is applied pneumatically to this abraded original finish. The resulting waterborne basecoat film was flashed at room temperature for 2 minutes and subsequently dried in a forced-air oven at 70 C. for 10 minutes. A so-called 80 C. two-component clearcoat material (FF230500 2K refinish clearcoat, scratchproof, from BASF Coatings GmbH) was applied to the dried waterborne basecoat film. The resulting clearcoat film was flashed at room temperature for 20 minutes. The waterborne basecoat film and the clearcoat film were then cured in a forced-air oven at 80 C. for 30 minutes.

(26) The steel panels thus treated were then stored over a period of 10 days in a conditioning chamber under CH test conditions according to DIN EN ISO 6270-2:2005-09. 24 hours after removal from the conditioning chamber, the panels were then inspected for blistering and swelling.

(27) The occurrence of blisters was assessed as follows through a combination of 2 values: The number of blisters was evaluated by a quantitative figure from 1 to 5, with ml denoting very few and m5 very many blisters. The size of the blisters was evaluated by a size figure again from 1 to 5, with g1 denoting very small and g5 very large blisters. The designation m0g0, accordingly, denotes a paint system which is blister-free after condensation-water storage, and represents a satisfactory result in terms of blistering.

(28) TABLE-US-00003 TABLE 2 Blistering and swelling of waterborne basecoat materials 1 and E1 to E3 WBM Blistering Swelling Assessment 1 m5g1 none unsat E1 m0g0 none sat E2 m0g0 none sat E3 m0g0 none sat

(29) Key: m=number of blisters g=size of blisters sat=satisfactory result unsat=unsatisfactory result

(30) The results confirm that when the polyesters of the invention are used there are no longer any blisters after condensation-water storage and there are no longer any visible instances of swelling.

(31) 2. Preparation of a Silver Waterborne Basecoat Material 2

(32) The components listed under aqueous phase in table B were stirred together in the order stated to form an aqueous mixture. In the next step an organic mixture was prepared from the components listed under organic phase. The organic mixture was added to the aqueous mixture. The combined mixture was then stirred for 10 minutes and adjusted, using deionized water and dimethylethanolamine, to a pH of 8 and to a spray viscosity of 58 mPas under a shearing load of 1000 s.sup.1 as measured with a rotary viscometer (Rheomat RM 180 instrument from Mettler-Toledo) at 23 C.

(33) TABLE-US-00004 TABLE B Parts by Component weight Aqueous phase 3% strength Na-Mg phyllosilicate 26 solution Deionized water 21.7 Butyl glycol 2.8 Polyurethane-modified polyacrylate; 4.5 prepared as per page 7, line 55 to page 8, line 23 of DE 4437535 A 50%, strength by weight solution of 0.6 DSX 1550 (BASF), rheological agent P1 13.3 Tetramethyldecynediol 0.3 (surfactant from BASF) Melamine-formaldehyde resin 4.1 (Cymel 203 from Cytec) 10% strength dimethylethanolamine in 0.3 water Polyurethane-based graft copolymer; 1.8 prepared as per page 19, line 44 to page 20, line 21 of DE 19948004 A Tetramethyldecynediol 1.6 (surfactant from BASF) 3% strength by weight aqueous Viscalex 3.9 HV 30 solution; rheological agent, available from BASF Organic phase Mixture of two commercial aluminum 6.2 pigments, available from Altana-Eckart Butyl glycol 7.5 P1 5
Waterborne Basecoat Material E4:

(34) To prepare the inventive waterborne basecoat material E4, a paint was prepared in the same way as for the preparation of the waterborne basecoat material 2, using DP1 instead of polyester P1 both in the aqueous phase and in the organic phase. DP1 of the organic phase was first dissolved in a third of the amount of butyl glycol present in the organic phase. Additionally 1 part by weight of butyl glycol was added to the organic phase to balance out the solvent constituent. DP1 of the aqueous phase was dissolved in 2.66 parts by weight of butyl glycol, thereby also balancing out the solvent content of the aqueous phase.

(35) Waterborne Basecoat Material E5:

(36) To prepare the inventive waterborne basecoat material E5, a paint was prepared in the same way as for the preparation of the waterborne basecoat material 2, using DP2 instead of polyester P1 both in the aqueous phase and in the organic phase. DP2 of the organic phase was first dissolved in a third of the amount of butyl glycol present in the organic phase. Additionally part by weight of butyl glycol was added to the organic phase to balance out the solvent constituent. DP2 of the aqueous phase was dissolved in 2.66 parts by weight of butyl glycol, thereby also balancing out the solvent content of the aqueous phase.

(37) Waterborne Basecoat Material E6:

(38) To prepare the inventive waterborne basecoat material E6, a paint was prepared in the same way as for the preparation of the waterborne basecoat material 2, using DP3 instead of polyester P1 both in the aqueous phase and in the organic phase. DP3 of the organic phase was first dissolved in a third of the amount of butyl glycol present in the organic phase. Additionally part by weight of butyl glycol was added to the organic phase to balance out the solvent constituent. DP3 of the aqueous phase was dissolved in 2.66 parts by weight of butyl glycol, thereby also balancing out the solvent content of the aqueous phase.

(39) TABLE-US-00005 TABLE 3 Compositions of waterborne basecoat materials 2 and E4 to E6 WBM [wt %] polymer solids 2 10.98 P1 E4 10.98 DP1 E5 10.98 DP2 E6 10.98 DP3

(40) The weight percentage figures in table 3 are based on the overall weight of the waterborne basecoat material.

(41) Comparison between waterborne basecoat materials 2 and E4 to E6

(42) To determine the stability with respect to the occurrence of blisters and swelling after condensation-water storage, the multicoat paint systems were produced in accordance with the following general protocol:

(43) A steel panel coated with a standard cathodic electrocoat (Cathoguard 800 from BASF Coatings GmbH) and with dimensions of 1020 cm was coated with a standard surfacer (ALG 670173surfacer, medium-gray, from Hemmelrath). After preliminary drying of the aqueous surfacer at 80 C. over a period of 10 minutes, the surfacer was baked at a temperature of 190 C. over a period of 30 minutes.

(44) The respective waterborne basecoat material from table 3 was then applied pneumatically. The resulting waterborne basecoat film was flashed at room temperature for 2 minutes and subsequently dried in a forced-air oven at 70 C. for 10 minutes. A customary two-component clearcoat material (Progloss 345 from BASF Coatings GmbH) was applied to the dried waterborne basecoat film. The resulting clearcoat film was flashed at room temperature for 20 minutes. The waterborne basecoat film and the clearcoat film were then cured in a forced-air oven at 160 C. for 30 minutes. The present system represents an overbaked original system and will be referred to below as the original finish.

(45) This original finish is abraded with abrasive paper and then the respective waterborne basecoat material from table 3 is applied pneumatically to this abraded original finish. The resulting waterborne basecoat film was flashed at room temperature for 2 minutes and subsequently dried in a forced-air oven at 70 C. for 10 minutes. A so-called 80 C. two-component clearcoat material (FF230500 2K refinish clearcoat, scratchproof, from BASF Coatings GmbH) was applied to the dried waterborne basecoat film. The resulting clearcoat film was flashed at room temperature for 20 minutes. The waterborne basecoat film and the clearcoat film were then cured in a forced-air oven at 80 C. for 30 minutes.

(46) The steel panels thus treated were then stored over a period of 10 days in a conditioning chamber under CH test conditions according to DIN EN ISO 6270-2:2005-09. 24 hours after removal from the conditioning chamber, the panels were then inspected for blistering and swelling.

(47) The occurrence of blisters was assessed as follows through a combination of 2 values: The number of blisters was evaluated by a quantitative figure from 1 to 5, with m1 denoting very few and m5 very many blisters. The size of the blisters was evaluated by a size figure again from 1 to 5, with g1 denoting very small and g5 very large blisters. The designation m0g0, accordingly, denotes a paint system which is blister-free after condensation-water storage, and represents a satisfactory result in terms of blistering.

(48) TABLE-US-00006 TABLE 4 Blistering and swelling of waterborne basecoat materials 2 and E4 to E6 WBM Blistering Swelling Assessment 2 m5g4 none unsat E4 m0g0 none sat E5 m0g0 none sat E6 m0g0 none sat

(49) Key: m=number of blisters g=size of blisters sat=satisfactory result unsat=unsatisfactory result

(50) The results confirm that when the polyesters of the invention are used there are no longer any blisters after condensation-water storage and there are no longer any visible instances of swelling.