WO2022238315A1

WO2022238315A1 - Polyester polyols carrying a terminal alcohol- or acid-derived residue suitable for use in solvent- based two-component coating compositions

Info

Publication number: WO2022238315A1
Application number: PCT/EP2022/062456
Authority: WO
Inventors: Florian Ludwig GEYER; Sebastian Roller
Original assignee: Basf Se
Priority date: 2021-05-10
Filing date: 2022-05-09
Publication date: 2022-11-17
Also published as: EP4337707A1

Abstract

The present invention relates to polyester polyols (1) carrying at least one group selected from a group including formula (I) and formula (I´) wherein R1 and R2 are indenpendently and at each occurrence a residue comprising 1 to 20 carbon atoms, with the proviso that R1 is not -CH2-CH2-O-C(=O)-CH=CH2 or -CH2CH2-O-C(=O)-C(CH3)=CH2, to solutions comprising at least one polyester polyol (1) and at least one organic solvent, to a process for the preparation of the polyester polyol (1), to intermediate monoisocyanates used in this process, to an organic solvent-based two-component coating composition comprising a) a first component (K1) comprising (i) the polyester polyol (1) and (ii) optionally at least one polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention (D1), and b) a second component (K2) comprising (i) at least one compound, oligomer or polymer carrying more than one N=C=O group or blocked N=C=O group (F1), and to substrates coated with this coating composition.

Description

Polyester Polyols Carrying a Terminal Alcohol- or Acid-Derived Residue suitable for Use in Sol- vent-Based Two-Component Coating Compositions

Description

The present invention relates to polyester polyols carrying a terminal alcohol- or acid-derived residue linked via isophorone diisocyanate or via toluene-2, 4-diisocyanate to the polyester poly- ol, to solutions comprising the polyester polyols, to a process for the preparation of the polyester polyol, to intermediate monoisocyanates used in the process, to organic solvent-based two component coating compositions suitable for yielding polyurethane coatings comprising the pol- yester polyols, and to substrates coated with these coating compositions.

Organic solvent-based two-component coating compositions suitable for yielding polyurethane coatings are widely used in various applications, for example as coating composition for auto- motive and industrial coatings. The organic solvent-based two-component coating compositions can comprise a polyester polyol as one of the components.

The preparation of modified polyester polyols by the reaction of polyester polyols with a mono- sisocyanate, which monoisocyanate is formed from equimolar amounts of isophorone diisocya- nate and 2-hydroxyethyl methacrylate, is known in the art.

Hadavand, B.S; Najafi, F.; Saeb, M.R. High performance polymers 2017, 29(6), 651-662 de- scribe a process for the preparation of polyester polyols prepared by first reacting equimolar amounts of isophorone diisocyanate and 2-hydroxyethyl methacrylate, followed by reacting the reaction product of the first step with various polyester polyols obtained from the reaction of 1,1,1 -(trimethylol) propane and 2,2-bis(hydroxymethyl) propionic acid, using varying amounts of of 1 ,1,1 -(trimethylol) propane and 2,2-bis(hydroxymethyl) propionic acid, and various catalysts. Hadavand does not disclose the use of the polyester polyols in organic solven-based two- component coating compositions suitable for yielding a polyurethane coating.

Organic solvent-based two-component coating compositions suitable for yielding a polyurethane coating should ideally have a good drying behavior, and the coatings formed from the organic solvent-based two-component coating composition should show good mechanical properties.

It was the object of the present invention to provide polyester polyols suitable for use in organic solvent-based two-component coating compositions yielding a polyurethane coating, which coating compositions show a good drying behavior, in particular a short cotton wool drying time and a short sand drying time.

This object is solved by the polyester polyol of claim 1, the solution comprising the polyester polyols of claim 13, the process for the preparation of the polyester polyols of claim 14, the in- termediate monoisocyanate of claim 16, the organic solvent-based two-component coating composition of claim 17 and 18 and the substrate of claim 19.

The polyester polyol of the present invention is polyester polyol (1) carrying at least one group selected from the group consisting of

wherein

R¹ and R² are independently and at each occurrence a residue comprising 1 to 20 carbon at- oms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH₂.

The polyester polyol (1) carrying at least one group selected from the group consisting of

wherein

R¹ and R² are independently and at each occurrence a residue comprising 1 to 20 carbon at- oms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O))C(CH₃)=CH_2, preferably comprises units derived from a) at least one component carrying at least one COOH group or a derivative thereof (A), where- in component A comprises

(i) at least one compound carrying two COOH groups or a derivative thereof (A1), and b) at least one component carrying at least one OH group and no COOH group (B), wherein component B comprises

(i) at least one compound or oligomer carrying at least three OH groups and no COOH group (B1), and

(ii) optionally at least one compound, oligomer or polymer carrying two OH groups and no COOH group (B2).

The compound carrying two COOH groups or a derivative thereof (A1) can also carry at least one group independently selected from the group consisting of OH group and NH₂ group.

Compounds carrying two COOH groups or a derivative thereof (A1) have preferably a molecular weight of below 500 g/mol, and most preferably of below 250 g/mol.

Compounds carrying two COOH groups or derivatives thereof (A1) can be an aliphatic, alicyclic or aromatic compound carrying two COOH groups or derivatives thereof.

Aromatic compounds carrying two COOH groups are compounds carrying two COOH groups, wherein at least one COOH group is directly attached to an aromatic ring. Alicyclic compounds carrying two COOH groups are compounds carrying two COOH groups, which comprise at least one alicyclic ring and wherein each COOH group is not directly attached to an aromatic ring. Aliphatic compounds carrying two COOH groups are compounds carrying two COOH groups, which comprise no alicyclic ring, and wherein each COOH group is not directly attached to an aromatic ring. Preferred aliphatic and alicyclic compounds carrying two COOH groups or deriva- tives thereof do not carry aromatic rings.

Derivatives of the compounds carrying two COOH groups can be (i) the corresponding anhy- dride in monomeric or polymeric form, (ii) the corresponding mono- or di-Ci-4-alkyl esters such as monomethyl ester, dimethyl ester, monoethyl ester, diethyl ester or mixed methyl ethyl esters (iii) the corresponding amides, or (iv) the corresponding acid halides such as chlorides or bro- mides.

Examples of Ci-4-alkyl are methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl and tert-butyl.

Preferred derivatives of component A1 are (i) the corresponding anhydride in monomeric form or (ii) the corresponding mono- or di-C_1-4-alkyl esters.

Examples of aliphatic compounds carrying two COOH groups are oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelinic acid, suberic acid, azelaic acid, sebacic acid, 1,11-undecanedicarboxylic acid, 1 ,12-dodecanedicarboxlylic acid, maleic acid, fumaric acid, 2- methylmalonic acid, 2-ethylmalonic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid, itaconic acid, 3,3-dimethylglutaric acid, 2-phenylmalonic acid 2-phenylsuccinic acid, glutamic acid, as- partic acid, tartaric acid and malic acid.

Examples of alicyclic compounds carrying two COOH groups are cyclopentane- 1, 2-dicarboxylic acid, cyclopentane-1, 3-dicarboxylic acid, cyclohexane-1, 2-dicarboxylic acid, cyclohexane- 1,3- dicarboxylic acid, cyclohexane-1 ,4-dicarboxylic acid, cycloheptane-1, 2-dicarboxylic acid, 1,2- bis(carboxymethyl)-cyclohexane, 1,3-bis(carboxymethyl)-cyclohexane and 1,4-bis(carboxy- methyl)-cyclohexane.

Examples of aromatic compounds carrying two COOH groups are 2-5-furandicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and bis(4-carboxyphenyl) methane.

Preferably, compound A1 is at least one aliphatic or alicyclic compound carrying two COOH groups or a derivative thereof. More preferably, compound A1 is at least one alicyclic compound carrying two COOH groups or derivatives thereof. Even more preferably, compound A1 is at least one alicyclic compound carrying two COOH groups independently selected from the group consisting of cyclohexane-1, 2-dicarboxylic acid, cyclohexane-1, 3-dicarboxylic acid, cyclohex- ane-1,4-dicarboxylic acid and derivatives thereof. Most preferably, compound A1 is cyclohex- ane-1 , 2-dicarboxylic acid or a derivative thereof. In particular, compound A1 is cyclohexane-1, 2- dicarboxylic acid anhydride.

Component A can comprise further components carrying at least one COOH group or a deriva- tive thereof, which are different from component A1 , for example compounds carrying at least three COOH groups or derivatives thereof (A2) and compounds carrying only one COOH group or derivatives thereof (A3).

The further components A such as A2 and A3 can also optionally carry at least one group inde- pendently selected from the group consisting of OH group and NH2 group.

Derivatives thereof are as defined above.

Examples of compounds carrying at least three COOH groups or derivatives thereof (A2) are 1,3,5-cyclohexanetricarboxylic acid, cis- and trans-aconitic acid, citric acid, isocitric acid, tricar- ballylic acid, 1,2,4-benzenetricarbocxylic acid, 1,3,5-benzenetricarbocxylic acid, 1, 2,4,5- benzenetetracarboxylic acid, mellitic acid and pyromellitic dianhydride.

Examples of compounds carrying one COOH (A3) or derivatives thereof (A2) are dime- thylolpropionic acid or dimethylolbutyric acid.

The compound or oligomer carrying at least three OH groups and no COOH group (B1) has preferably a molecular weight of below 1500 g/mol, more preferably 1000 g/mol, most prefera- bly of below 500 g/mol.

The compound or oligomer carrying at least three OH groups and no COOH group (B1) can also carry heteroatom-containing groups such as isocyanurate, ester or ether groups.

Examples of compounds or oligomers carrying at least three OH groups and no COOH group (B1) are compounds or oligomers carrying three OH groups and no COOH group and com- pounds or oligomers carrying at least four OH groups and no COOH group.

Examples of compounds or oligomers carrying three OH groups and no COOH group are glyc- erol, butane-1, 2, 3-triol, butane-1, 2, 4-triol, pentane-1, 2, 3-triol, pentane-1, 2, 4-triol, pentane-1, 2,5- triol, hexane-1 ,2, 3-triol, hexane-1 ,2, 4-triol, hexane-1 , 2, 5-triol, hexane-1 , 2, 6-triol, hexane-1, 3,4- triol, hexane-1, 3, 5-triol, hexane-1 ,3, 6-triol, hexane-1 , 4, 5-triol, tetrahydrofuran-2, 3, 4-triol, tetra- hydrofuran-2, 3, 5-triol, 2-(hydroxymethyl)tetrahydrofuran-3,4-diol, 5-(hydroxymethyl)tetra- hydrofuran-2,4-diol, (3-hydroxytetrahydrofuran-2,5-diyl)dimethanol, 1-(3-hydroxytetrahydro- furan-2-yl)ethane-1,2-diol, 1-(4-hydroxytetrahydrofuran-2-yl)ethane-1,2-diol, 2-(2-hydroxy- ethyl)tetrahydrofuran-3,4-diol, 2-(1-hydroxyethyl)tetrahydrofuran-3,4-diol, 6-(hydroxymethyl)- tetrahydro-2H-pyran-2,3-diol, 6-(hydroxymethyl)tetrahydro-2H-pyran-2,4-diol, 6-(hydroxy- methyl)tetrahydro-2H-pyran-2,5-diol, 1 ,3,5-tris(hydroxymethyl)isocyanurate, 1,3,5-tris(2- hydroxyethyl)isocyanurate, 1 ,3,5-tris(2-hydroxyisopropyl)isocyanurate, 1 ,3,5-tris(2- hydroxypropyl)isocyanurate, 1,3,5-tris(2-hydroxybutyl)isocyanurate, trimethylolmethane, 1 ,1 ,1- trimethylolethane and 1,1,1 -trimethylol propane, as well as ethoxylated, propoxylated and/or butoxylated derivatives thereof. Examples of compounds or oligomers carrying at least four OH groups and no COOH group are pentane-1 ,2,3,4-tetraol, pentane-1 ,2,3,5-tetraol, pentane-1 ,2,4,5-tetraol, hexane-1 ,2,3,4-tetraol, hexane-1 ,2,3,6-tetraol, hexane-1 ,2,5,6-tetraol, hexane-1 ,2,4,6-tetraol, hexane-1 ,2,3,5-tetraol, hexane-1, 2, 3, 5-tetraol, tetrahydrofuran-2,3,4,5-tetraol, 5-(hydroxymethyl)tetrahydrofuran-2,3,4- triol, 2,5-bis(hydroxymethyl)tetrahydrofuran-3,4-diol, 2-(1,2-dihydroxyethyl)tetrahydrofuran-3,4- diol, 6-(hydroxymethyl)tetrahydro-2H-pyran-2,3,5-triol, 6-(hydroxymethyl)tetrahydro-2H-pyran- 2,3,4-triol, 6-(hydroxymethyl)tetrahydro-2H-pyran-2,4,5-triol, pentaerythritol, di(pentaerythritol), diglycerol, polyglycerol, di(trimethylolpropane), inositol, sugars such as glucose, fructose and sucrose, sugar alcohols such as sorbitol, mannitol, threitol, erythritol, adonitol (ribitol), arabitol (lyxitol), xylitol, dulcitol (galactitol), malitol and isomalt, as well as ethoxylated, propoxylated and/or butoxylated derivatives thereof.

Preferably, the compounds or oligomers carrying at least three OH groups and no COOH group (B1) are compounds or oligomers carrying three OH groups and no COOH group. More prefer- ably, the compounds or oligomers carrying at least three OH groups and no COOH group (B1) are 1 ,3,5-tris(hydroxymethyl)isocyanurate, 1 ,3,5-tris(2-hydroxyethyl)isocyanurate, 1 ,3,5-tris(2- hydroxyisopropyl)isocyanurate, 1 ,3,5-tris(2-hydroxypropyl)isocyanurate ,1 ,3,5-tris(2- hydroxybutyl)isocyanurate, trimethylolmethane, 1 ,1 ,1-trimethylolethane or 1,1,1 -trimethylol- propane, as well as ethoxylated, propoxylated or butoxylated derivatives thereof. Even more preferably, the compounds or oligomers carrying at least three OH groups and no COOH group (B1) are 1,3,5-tris(2-hydroxyethyl)isocyanurate or 1 ,1,1-trimethylolpropane, as well as ethox- ylated, propoxylated or butoxylated derivatives thereof. Most preferably, B1 is a compound car- rying at least three OH groups and no COOH group and is 1,1 ,1-trimethylolpropane.

The compound, oligomer or polymer carrying two OH groups and no COOH group (B2) prefera- bly has a molecular weight of below 1000 g/mol, more preferably of below 500 g/mol, and most preferably of below 250 g/mol.

The compound, oligomer or polymer carrying two OH groups and no COOH group (B2) can also carry isocyanurate, ester or ether groups.

The compound, oligomer or polymer carrying two OH groups and no COOH group (B2) is pref- erably an aliphatic or alicyclic compound carrying two OH groups and no COOH group, a poly- ether diol or a polyester diol.

Alicyclic compounds carrying two OH groups and no COOH group are compounds carrying two OH groups, which comprise at least one alicyclic ring and wherein each OH group is not directly attached to an aromatic ring. Aliphatic compounds carrying two OH groups and no COOH group are compounds carrying two OH groups, which comprise no alicyclic ring, and wherein each OH group is not directly attached to an aromatic ring. Preferred aliphatic and alicyclic compounds carrying two OH groups and no COOH group, do not comprise aromatic rings. Examples of aliphatic compounds carrying two OH groups and no COOH group (B2) are eth- ylene glycol, propane-1, 2-diol, propane-1 , 3-diol, butane-1, 2-diol, butane-1, 3-diol, butane-1, 4- diol, butane-2, 3-diol, pentane-1 , 2-diol, pentane-1, 3-diol, pentane-1, 4-diol, pentane-1, 5-diol, pen- tane-2, 3-diol, pentane-2, 4-diol, hexane-1, 2-diol, hexane-1, 3-diol, hexane-1, 4-diol, hexane-1 ,5- diol, hexane-1, 6-diol, hexane-2, 5-diol, heptane-1, 2-diol, heptane-1, 7-diol, octane-1, 8-diol, oc- tane-1, 2-diol, nonane-1, 9-diol, decane-1 , 2-diol, decane-1 , 10-diol, dodecane-1, 2-diol, dodecane- 1,12-diol, hexa-1,5-diene-3, 4-diol, neopentyl glycol, 2-methyl-pentane-2, 4-diol, 2,4-dimethyl- pentane-2, 4-diol, 2-ethyl-hexane- 1 , 3-diol, 2, 5-dimethyl-hexane-2, 5-diol, 2,2,4-trimethyl-pentane- 1, 3-diol, pinacol, 2,5-bis(hydroxymethyl)tetrahydrofuran, tetrahydrofuran-2, 3-diol, tetrahydrofu- ran-2, 4-diol, tetrahydrofuran-2, 5-diol, 5-(hydroxymethyl)tetrahydrofuran-2-ol, 5-(hydroxymethyl)- tetrahydrofuran-3-ol, 2-(hydroxymethyl)tetrahydrofuran-3-ol, 2-ethyltetrahydrofuran-3, 4-diol, 2- (2-hydroxyethyl)tetrahydrofuran-3-ol, 5-(2-hydroxyethyl)tetrahydrofuran-3-ol, 2-(1-hydroxyethyl)- tetrahydrofuran-3-ol, 5-(1-hydroxyethyl)tetrahydrofuran-3-ol, 6-(hydroxymethyl)tetrahydro-2H- pyran-2-ol, 6-(hydroxymethyl)tetrahydro-2H-pyran-3-ol, 2-(hydroxymethyl)tetrahydro-2H-pyran- 4-ol, 2-(hydroxymethyl)tetrahydro-2H-pyran-3-ol and hydroxypivalinic acid neopentyl glycol es- ter.

Examples of alicyclic compounds carrying two OH groups and no COOH group (B2) are 2, 2,4,4- tetramethyl-1,3-cyclobutandiol, cyclopentane-1, 2-diol, cyclopentane-1, 3-diol, 1,2-bis(hydroxy- methyl) cyclopentane, 1,3-bis(hydroxymethyl) cyclopentane, cyclohexane-1, 2-diol, cyclohexane- 1, 3-diol, cyclohexane-1, 4-diol, 1,1-bis(hydroxymethyl)-cyclohexane, 1,2-bis(hydroxymethyl)- cyclohexane, 1,3-bis(hydroxymethyl)-cyclohexane, 1,4-bis(hydroxymethyl)-cyclohexane, 1,1- bis(hydroxyethyl)-cyclohexane, 1 ,2-bis(hydroxyethyl)cyclohexane, 1 ,3-bis(hydroxyethyl)- cyclohexane and 1,4-bis(hydroxyethyl)cyclohexane, cycloheptane-1, 3-diol, cycloheptane- 1 ,4- diol and cycloheptane-1, 2-diol.

Examples of polyether diols are diethylene glycol, triethylene glycol, dipropylene glycol, tripro- pylene glycol, polyethylene glycols H0(CH₂CH₂0)_n-H, polypropylene glycols HO(CH(CH₃)-CH₂- 0)_n-H, n being an integer and n >= 4, polyethylene-polypropylene glycols, the sequence of the ethylene oxide or propylene oxide units being blockwise or random, polytetramethylene glycols, and polytetrahydrofuran.

An example of a polyester diol is polycaprolactone prepared from caprolactone and a diol.

Component B can comprise further components carrying at least one OH group and no COOH group, which are different from B1 and B2, for example compounds carrying only one OH group and no COOH group (B3).

Examples of compounds carrying only one OH group and no COOH group (B3) are methanol, ethanol, 1-propanol, isopropanol, 1-butanol, sec-butanol, isobutanol, tert-butanol, 1-pentanol, 3- methylbutan-2-ol, 2-methylbutan-2-ol, fatty alcohols such as 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1 tetradecanol, 1-hexadecanol, 1- octadecanol, cis-9-hexadecen-1-ol, cis-9-octadecen-1-ol, cis,cis-9,12-octadecadien-1-ol, 6,9,12- octadecatrien-1-ol, 1-methoxypropan-2-ol, cyclopentanol, cyclohexanol, cycloheptanol, 1- methylcyclopentan-1-ol, 1-methylcyclohexan-1-ol, poly(ethylene gycol) monomethyl ether, polypropylene gycol) monomethyl ether, furfuryl alcohol and tetrahydrofurfuryl alcohol.

The ratio of mol COOH groups of all components A1/mol COOH groups of all components A is preferably in the range of 60 to 100%, more preferably in th range of 80 to 100%, even more preferably in the range of 90 to 100%, and most preferably 100%.

The ratio of mol OH groups of all components B1/mol OH groups of all components B is prefer- ably in the range of 60 to 100%, more preferably in th range of 80 to 100%, even more prefera- bly in the range of 90 to 100%, and most preferably 100%.

The ratio of mol OH groups of all components A and B/mol COOH groups of all components A is preferably in the range of 1.05/1 to 5/1, more preferably in the range of 1.10/1 to 3/1, even more preferably in the range of 1.15/1 to 2/1 , and most preferably in the range of 1.20/1 to 1.7/1.

The ratio weight all units derived from all components A and B/weight all groups selected from the group consisting of (I), (II), (III), (G), (IG), (IN^'), (IV), (V), (VI), (IV^'), (V^') and (VI^') is preferably in the range of 15.0/1 to 1/15.0, more preferably in the range of 10.0/1 to 1/5.0, and most pref- erably in the range of 7.0/1 to 1/3.0.

Preferably, at least 60 weight% of the polyester polyol (1) of the present invention consists of at least one group selected from the group consisting of (I), (II), (III), (G), (IG), (III^'), (IV), (V), (VI), (IV^'), (V^') and (VI^') and of units derived from compounds A1 and B1. More preferably, at least 75 weight% of the polyester polyol (1) of the present invention consists of at least one group selected from the group consisting of (I), (II), (III), (G), (IG), (IN^'), (IV), (V), (VI), (IV^'), (V^') and (VI^') and of units derived from compounds A1 and B1. Even more preferably, at least 90 weight% of the polyester polyol (1) of the present invention consists of at least one group se- lected from the group consisting of (I), (II), (III), (G), (IG), (IN^'), (IV), (V), (VI), (IV^'), (V^') and (VI^') and of units derived from compounds A1 and B1. Most preferably, at least 95 weight% of the polyester polyol (1) of the present invention consists of at least one group selected from the group consisting of (I), (II), (III), (G), (IG), (IN^'), (IV), (V), (VI), (IV^'), (V^') and (VI^') and of units derived from compounds A1 and B1. In particular, the polyester polyol (1) of the present inven- tion consists of at least one group selected from the group consisting of (I), (II), (III), (G), (IG), (III^'), (IV), (V), (VI), (IV^'), (V^') and (VI^') and of units derived from compounds A1 and B1.

The polyester polyols (1) of the present invention are preferably so-called “hyperbranched” pol- yester polyols. “Hyperbranched” polyester polyols are defined to be polyester polyols of tree-like structure comprising non-terminal monomer units derived from components, which have at least three groups individually selected from the group consisting of OH group and COOH group or a derivative thereof (such as B1), wherein at least one of these groups has not reacted to form a linkage between two monomer units. Preferably, the molar ratio of non-terminal monomer units derived from components, which have at least three groups individually selected from the goup consisting of OH group and COOH group or derivative thereof (such as B1), wherein at least one of these groups has not reacted to form a linkage between two monomer units to non- terminal monomer units derived from components, which have at least three groups individually selected from the goup consisting of OH group and COOH group or derivative thereof (such as B1), wherein all of these groups have reacted to form a linkage between two monomer units is at least 5/95, more preferably at least 10/90, even more preferably at least 30/70. This molar ratio can be determined by methods known in the art, for example ¹³C-NMR or titration.

The polyester polyols (1) of the present invention preferably have a hydroxyl number in the range of 30 to 400 mg KOH/g, more preferably in the range of 40 to 300 mgKOH/g, most pref- erably in the range of 55 to 230 mg KOH/g. The hydroxyl number is determined according to DIN 53240, 2016.

The polyester polyols (1) of the present invention preferably have an acid number in the range of 1 to 150 mg KOH/g, more preferably in the range of 10 to 125 mg KOH/g, and most prefera- bly in the range of 20 to 100 mg KOH/g. The acid number is determined according to DIN 53402, 1990.

The polyester polyols (1) of the present invention preferably have a number average molecular weight Mn in the range of 400 to 10000 g/mol, more preferably in the range of 400 to 5000 g/mol, even more preferably in the range of 500 to 2500 g/mol and most preferably in the range of 600 to 2000 g/mol. The number average molecular weight Mn is determined using gel per- meation chromatography calibrated to a polystyrene standard.

The polyester polyols (1) of the present invention preferably have a weight average molecular weight Mw in the range of 400 to 30000 g/mol, more preferably in the range of 700 to 15000 g/mol, even more preferably in the range of 1000 to 10000 g/mol and most preferably in the range of 1200 to 12000 g/mol. The weight average molecular weight Mw is determined using gel permeation chromatography calibrated to a polystyrene standard.

The polyester polyols (1) of the present invention preferably have a polydispersity Mw/Mn in the range of 1.1/1.0 to 20.0/1.0, more preferably in the range of 1.2/1.0 to 10.0/1.0 and most prefer- ably in the range of 1.3/1.0 to 5.0/1.0.

The polyester polyol (1) of the present invention can have a glass transition temperature (Tg) in the range of -20 to 60 °C, preferably in the range of -5 to 30 °C.

The polyester polyol (1) of the present invention preferably carries at least one group selected from the group consisting of

wherein R¹ and R² are indenpendently and at each occurrence a residue comprising 1 to 20 carbon at- oms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH₂.

The polyester polyol (1) of the present invention more preferably carries at least one group, which is selected from the group consisting of

wherein

R¹ is a residue comprising 1 to 20 carbon atoms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH₂.

R¹ and R² can be independently any residue comprising 1 to 20 carbon atoms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH_2.

Examples of residues comprising 1 to 20 carbon groups are C_1-20-alkyl, C_2-20-alkenyl, C_6-14-aryl, C_3-12-cycloalkyl, C_4-12-cycloalkenyl, Cs-i4-bicyclic system, C_9-20-tri cyclic system, wherein

Ci-2o-alkyl can be substituted with one or more substituents selected from the group consisting of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, tolyl, O- C(=O)CH=CH₂ and O-C(=O)-C(CH₃)=CH_2, provided the overall number of carbon atoms is maxi- imum 20,

C2-2o-alkenyl can be substituted with one or more substituents selected from the group consist- ing of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cycloooctyl, phenyl, tolyl, O- C(=O)-CH=CH₂ and O-C(=O)-C(CH₃)=CH_2, provided the overall number of carbon atoms is maximum 20, C_6-14-aryl can be substituted with one or more substitutent selected from the group consisting of C_1-6-alkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, tolyl, O-C(=O)-CH=CH₂ and O-C(=O)-C(CH₃)=CH_2, provided the overall number of carbon atoms is maximum 20,

C_3-12-cycloalkyl, C_4-12-cycloalkenyl, C_6-14-bicyclic syste and C_9-20- tricyclic system can be inde- pendently substituted with one or more substitutent selected from the group consisting of C_1-6- alkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, cyclooctyl, phenyl, tolyl, O- C(=O)-CH=CH₂ and O-C(=O)-C(CH₃)=CH_2, provided the overall number of carbon atoms is maximum 20. C_1-6-alkyl and C_1-20-alkyl can be branched or unbranched. Examples of C_1-6-alkyl are methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, isopentyl and hexyl. Exam- ples of C_1-20-alkyl are methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl.

C_2-20-alkenyl can be branched or unbranched. Examples of C2-2o-alkenyl are vinyl, prop-1 -enyl, allyl (prop-2-enyl), isopropenyl, but-1-enyl, but-2-enyl, but-3-enyl, isobutenyl, pent-1-enyl, pent-

2-enyl, pent-3-enyl, pent-4-enyl, isopentenyl, hex-1-enyl, hex-2-enyl, hex-3-enyl, hex-4-enyl, hex-5-enyl, hept-6-enyl, oct-7-enyl, non-8-enyl and dec-9-enyl.

Examples of C_6-14-aryl are phenyl, 1-naphthyl, 2-naphthyl and 9-phenanthryl.

Examples of C_3-12-cycloalkyl are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl and cyclododecyl.

Examples of C_4-12-cycloalkenyl are cyclobut-2-enyl, cyclopent-3-enyl, cyclohex-2-enyl, cyclohex-

3-enyl, cyclohept-3-enyl and cyclooct-3-enyl.

Examples of C_6-14-bicyclic systems are systems consisting of two condensed non-aromatic rings, spiro-type systems consisting of two non-aromatic rings and systems consisting of two bridged non-aromatic rings.

Non-aromatic rings are cycloalkanes or cycloalkenes.

Examples of C_6-14-bicyclic systems, which are systems consisting of two condensed non- aromatic rings, are

Examples of C_6-14-bicyclic systems, which are spiro-type systems consisting of two aliphatic rings, are

Examples of C_6-14-bicyclic systems, which are systems consisting of two bridged aliphatic rings, are

Examples of C_9-20-tri cyclic system are systems consisting of three condensed non-aromatic rings, spiro-type systems consisting of three non-aromatic rings, systems consisting of two bridged non-aromatic rings and a condensed one non-aromatic ring, and systems consisting of three bridged non-aromatic rings.

Examples of C_9-20-tricyclic systems, which are systems consisting of three condensed non- aromatic rings are

Preferably, R¹ and R² are independently a residue comprising 1 to 20 carbon atoms, but not comprising -O-C(=O)-CH=CH₂ or -O-C(=O)-C(CH₃)=CH₂ group. Examples of residues comprising 1 to 20 carbon atoms, but no -O-C(=O)-CH=CH₂ or -O-C(=O)- C(CH₃)=CH₂ group, are C_1-20-alkyl, C_2-20-alkenyl, C_6-14aryl, C_3-12-cycloalkyl, C_4-12-cycloalkenyl, C_6-14-bicyclic system and C_9-20-tri cyclic system, wherein

C_1-20-alkyl can be substituted with one or more substituents selected from the group consisting of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl and tolyl_, pro- vided the overall number of carbon atoms is maximum 20, C_2-20-alkenyl can be substituted with one or more substituents selected from the group consist- ing of cyclop ropy I, cyclobutyl, cycloheptyl, cyclohexyl, cycloheptyl, cycloooctyl, phenyl and tolyl_, provided the overall number of carbon atoms is maximum 20, C_6-14-aryl can be substituted with one or more substitutent selected from the group consisting of C_1-6-alkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, cyclooctyl, phenyl and tolyl_, provided the overall number of carbon atoms is maximum 20, C_3-12-cycloalkyl, C_4-12-cycloalkenyl, C_5-14-bicyclic system, C_9-20-tri cyclic system can be inde- pendently substituted with one or more substitutent selected from the group consisting of C_1-6- alkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, cyclooctyl, phenyl and tolyl_, provided the overall number of carbon atoms is maximum 20.

More preferably, R¹ and R² are independently a residue selected from the group consisting of C_3-12-cycloalkyl, C_4-12-cycloalkenyl, C_6-14-bicyclic system and C_9-20-tricyclic system, wherein C_3-12-cycloalkyl, C_4-12-cycloalkenyl, C_6-14-bicyclic system, C_9-20-tri cyclic system system can be independently substituted with one or more substitutent selected from the group consisting of C_1-6-alkyl, cyclopentyl and cyclohexyl, provided the overall number of carbon atoms of R¹ and R² each is maximum 20.

Even more preferably, R¹ and R² are independently a residue selected from the group consist- ing of C_3-12-cycloalkyl and C_{6- 14}- bi cyclic system, wherein C_3-12-cycloalkyl and C_6-14-bicyclic sys- tem can be independently substituted with one or more C_1-6-alkyl, provided the overall number of carbon atoms of R¹ and R² each is maximum 20.

Most preferably, R¹ is selected from the group consisting of formulae

In particular, R¹ is selected from the group consisting of formulae

More particular, R¹ is selected from the group consisting of formulae

Most preferably, R² has formula

Also part of the present invention are solutions comprising at least one polyester polyol (1) of the present invention and at least one organic solvent. Suitable organic solvents are esters, ketones, amides, ethers and aromatic hydrocarbons and mixtures thereof.

Examples of esters of are ethyl acetate, butyl acetate, 1-methoxy-2-propyl acetate, 2-butoxy ethyl acetate (butyl gycol acetate), propylene glycol diacetate, ethyl 3-ethoxy propionate, 3- methoxybutyl acetate, butyldiglycol acetate and propylene carbonate. Examples of ketones are acetone, methyl ethyl ketone and methyl isobutyl ketone. Examples of amides are dimethylfor- mamide (DMF) and N-methyl pyrrolidone (NMP). Example of ethers are glycol ethers such as dipropylene glycol dimethylether, and cyclic ethers such as tetrahydrofuran and 1,4-dioxane. Examples of aromatic hydrocarbons are xylene and solvent naphtha.

A preferred organic solvent is an ester or mixtures thereof. A more preferred organic solvent is an ester of a C_1-6-alkanoic acids with a C_1-6-alkanol such as butyl acetate and ethyl acetate. The most preferred organic solvent is butyl acetate.

The solid content of the solution is preferably in the range of 30 to 90% by weight, more prefer- ably 50 to 80% by weight, and most preferably in the range of 55 to 75% by weight.

The content of polyester polyol (1) in the solution is preferably in the range of 30 to 90% by weight, more preferably 50 to 80% by weight, and most preferably in the range of 55 to 75% by weight.

The viscosity of the solution is preferably in the range of 500 to 15000 mPa x s, more prefera- bly, in the range of 1000 to 10000 mPa x s. The viscosity is determined using a cone plate vis- cosimeter set to a shear rate of 100 s^-1 at 23 °C.

Also part of the present invention is a process for the preparation of a polyester polyol (1) of the present invention carrying at least one group selected from the group consisting of

which process comprises the step of reacting i) at least one monoisocyanate (2) selected from the group consisting of

with ii) at least one polyester polyol (3), wherein

R¹ and R² are indenpendently and at each occurrence a residue comprising 1 to 20 carbon at- oms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH₂.

The preferences of R¹ and R² are the same as given above for the polyester polyol (1) of the present invention.

The monoisocyanate (2) and the polyester polyol (3) are usually reacted in the presence of an organic solvent. The organic solvent can be any suitable organic solvent or a mixture thereof.

Preferably, the organic solvent is butyl acetate.

The monoisocyanate (2) and the polyester polyol (3) are usually reacted at a temperature in the range of 20 to 100°C, more preferably in the range of 40 to 90°C, most preferably 60 to 80°C.

The ratio of mol NCO groups of all monoisocynates (2)/mol OH groups of all polyester polyol (3) is preferably in the range of from 0.01/1.0 to 0.95/1.0, more preferably in the range of 0.05/1.0 to 0.90 /1.0 and most preferably in the range of 0.10/1.0 to 0.85/1.0

The reaction is usually stopped when no NCO bands can be detected by IR spectroscopy any- more.

The polyester polyol (3) preferably comprises units derived from a) at least one component carrying at least one COOH group or a derivative thereof (A), where- in component A comprises

The definition and preferences of the components A, A1 , B, B1 and B2 as well as the ratio of the components A, A1 , B, B1 and B2 to each other are the same as given above for the polyes- ter polyol (1) of the present invention.

Preferably, at least 60 weight% of the polyester polyol (3) consists of units derived from com- pounds A1 and B1. More preferably, at least 75 weight% of the polyester polyol (3) consists of units derived from compounds A1 and B1. Even more preferably, at least 90 weight% of the polyester polyol (3) consists of units derived from compounds A1 and B1. Most preferably, at least 95 weight% of the polyester polyol (3) consists of units derived from compounds A1 and B1. In particular, the polyester polyol (3) consists of units derived from compounds A1 and B1.

The polyester polyols (3) are preferably so-called “hyperbranched” polyester polyols.

The polyester polyols (3) preferably have a hydroxyl number in the range of 100 to 500 mg KOH/g, more preferably in the range of 140 to 400 mg KOH/g, most preferably in the range of 160 to 300 mg KOH/g. The hydroxyl number is determined according to DIN 53240, 2016.

The polyester polyols (3) preferably have an acid number in the range of 1 to 200 mg KOH/g, more preferably in the range of 30 to 150 mg KOH/g, and most preferably in the range of 50 to 120 mg KOH/g. The acid number is determined according to DIN 53402, 1990.

The polyester polyols of the present invention preferably have a number average molecular weight Mn in the range of 400 to 10000 g/mol, more preferably in the range of 400 to 5000 g/mol, even more preferably in the range of 400 to 2000 g/mol and most preferably in the range of 400 to 1800 g/mol. The number average molecular weight Mn is determined using gel per- meation chromatography calibrated to a polystyrene standard. The polyester polyols of the present invention preferably have a weight average molecular weight Mw in the range of 400 to 30000 g/mol, more preferably in the range of 400 to 15000 g/mol, even more preferably in the range of 500 to 8000 g/mol and most preferably in the range of 600 to 8000 g/mol. The weight average molecular weight Mw is determined using gel perme- ation chromatography calibrated to a polystyrene standard.

The polyester polyols (3) of the present invention preferably have a polydispersity Mw/Mn in the range of 1.1/1.0 to 20.0/1.0, more preferably in the range of 1.2/1.0 to 10.0/1.0 and most prefer- ably in the range of 1.3/1.0 to 5.0/1.0.

The polyester polyol (3) of the present invention can have a glass transition temperature (Tg) in the range of -20 to 60 °C, preferably in the range of -5 to 30 °C.

The polyester polyols (3) can be prepared by a process, which comprises the step of reacting a) at least one component carrying at least one COOH group or a derivative thereof (A), where- in component A comprises

The reaction of components A1 , B1 , and optionally B2 can be carried out in the presence or absence of solvent. Examples of suitable solvents include hydrocarbons such as n-heptane, cyclohexene, toluene, ortho-xylene, meta-xylene, para-xylene, xylene isomer mixture, ethylben- zene, chlorobenzene, ortho- and meta-dichlorobenzene. Of further suitability as solvents in the absence of acidic catalysts are ethers such as dioxane or tetrahydrofuran, and ketones such as methyl ethyl ketone and methyl isobutyl ketone. Preferably, the reaction is carried out in the absence of solvent.

Preferably, the water formed over the course of the reaction is removed continuously during the reaction. Water can be removed by distillation. Water can also be removed by stripping, which comprises passing a gas, which is inert under the reaction conditions, such as nitrogen, through the reaction mixture. Water can also be removed by performing the reaction in the presence of a water-removing agent such as MgSO₄and Na₂SO₄. It is also possible to combine the de- scribed methods for removal of water. Preferably, water is removed by distillation, optionally in combination with other water- removal methods.

If other volatile components, for example methanol or ethanol, are also formed over the course of the reaction, these can also be removed by distillation or stripping.

Preferably the reaction is performed in the presence of a catalyst. The catalyst can be selected from the group consisting of acidic inorganic, acidic organic catalysts and organometallic cata- lysts or mixtures thereof. More preferably, the catalyst is an acidic organometallic catalyst, most preferably titanium(IV) tetra(n-butoxide).

Examples of acidic inorganic catalysts are sulfuric acid, sulfates and hydrogen sulfates such as sodium hydrogen sulfate, phosphoric acid, phosphonic acid, hypophosphoric acid, aluminium sulfate hydrate, alum, acidic silica gel (pH <= 6, especially pH <= 5) and acidic aluminium oxide.

Examples of acidic organic catalysts are organic compounds containing phosphate groups, sul- fonic acid groups, sulfate groups or phosphonic acid groups, such as para-toluene sulfonic acid. Further examples of acidic organic catalysts are acidic ion exchangers such as polystyrene res- ins being crosslinked with divinylbenzene and containing sulfonic acid groups.

Examples of organometallic catalysts are organic aluminium catalysts such as tris(n- butyloxy)aluminium, tris(isopropyloxy)aluminium and tris(2-ethylhexoxy)aluminium, as well as organic titanium catalysts such as titanium(IV) tetra(n-butoxide), titanium(IV) tetra(isopropoxide) and titanium(IV) tetra(2-ethylhexoxide), organic tin catalysts such as dibutyltin oxide, diphenyl- tin oxide, dibutyltin dichloride, tin(ll)di(n-octanoate), tin(ll) di(2-ethylhexanoate), tin(ll) laurate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dimaleate and dioctyltin diacetate as well as organic zinc catalysts such as zinc acetate.

Preferably, the reaction is carried out under a gas, which is inert under the reaction conditions. Suitable inert gases include nitrogen, noble gases such as argon, carbon dioxide or combustion gases.

The reaction can be performed at a pressure in the range of 10 mbar to 10000 mbar, preferably at a pressure in the range of 10 to 2000 mbar, more preferably at a pressure in the range of 10 to 1200 mbar, most preferably at a pressure in the range of 300 to 1100 mbar.

The temperature is usully in the range of 60 to 250 °C, preferably, in the range of 100 to 220 °C and more preferably in the range of 120 to 200 °C. It is preferred that the temperature increases during the polyesterifcation reaction. The reaction can be monitored by the titration of the acid number or hydroxyl number. Usually, the reaction is stopped, when the target acid number or hydroxyl number of the polyester polyol is reached, by cooling the reaction mixture, preferably to below 100 °C, more preferably to be- low 90 °C, and diluting the reaction mixture with an organic solvent, for example butyl acetate, to yield a solution of the polyester polyol (3) in the organic solvent.

The monoisocyanate (2) selected from the group consisting of

can be prepared by reacting a diisocyanate selected from the group consisting of isophorone diisocyanate and toluene-2, 4-diisocyanate with R¹-OH (4) or R²-C(=O)-0H (5), wherein R¹ and R² are indenpendently and at each occurrence a residue comprising 1 to 20 carbon at- oms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH₂.

Toluene-2, 4-diisocyanate can be used in pure form or in a mixture with at least one of its iso- mers. Common mixtures of toluene-2, 4-diisocyanate with at least one of its isomers are mix- tures of toluene-2, 4-diisocyanate/toluene-2, 6-diisocyanate in a weight ratio of 80/20 or 65/35.

The definition and preferences of residues R¹ in R¹-OH and R² in R²-C(=O)-OH are the same as given above for the polyester polyol (1) of the present invention.

The ratio mol diisocyanate selected from the group consisting of isophorone diisocyanate and toluene-2, 4-diisocyanate /mol R¹-OH (4) or R²-C(=O)-OH (5) is preferably in the range of 0.8/11.0 to 1.2/1.0, more preferably in the range of 0.90/1.0 to 1.1/1.0, most preferably 1/1.

The reaction of diisocyanate selected from the group consisting of isophorone diisocyanate and toluene-2, 4-diisocyanate with R¹-OH (4) or R²-C(=O)-OH (5) is usually performed in the pres- ence of an organic solvent.

The organic solvent can be any suitable organic solvent or a mixture thereof. Preferably, the organic solvent is butyl acetate.

The reaction of isophorone diisocyanate with R¹-OH (4) or R²-C(=O)-OH (5) is usually per- formed at a temperature in the range of 20 to 100°C, more preferablyin the range of 40 to 90°C, most preferably 60 to 80°C. The reaction of toluene-2, 4-diisocyanate with R¹-OH (4) or R²- C(=O)-OH (5) is usually performed at a temperature below 10°C, more preferably below 5 °C, most preferably in the range of -5 to 5°C. The reaction can be performed in the presence of a catalyst such as tin neodecanoate or 1 ,4- diazabicyclo[2.2.2]octane. The reaction can be monitored by NCO content titration and is usually stopped when half of the NCO groups of the diisocyanate selected from the group consisting of isophorone diisocyanate and toluene-2, 4-diisocyanate has reacted. When the reaction was performed in an organic sol- vent, a solution of the monoisocyanate (2) in the organic solvent is obtained.

Also part of the present invention is monoisocyanate (2) selected from the group consisting of

wherein

The definition and preferences of residues R¹ and R² are the same as given above for the poly- ester polyol (1) of the present invention.

Also part of the present invention is an organic solvent-based two-component coating composi- tion comprising a) a first component (K1) comprising

(i) the polyester polyol (1) of the present invention carrying at least one group selected from the group consisting of

wherein

R¹ and R² are indenpendently and at each occurrence a residue comprising 1 to 20 carbon atoms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)- C(CH₃)=CH₂, and

(ii) optionally at least one polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention (D1) and b) a second component (K2) comprising (i) at least one compound, oligomer or polymer carry- ing more than one N=C=0 group or blocked N=C=0 group (F1).

Preferably, the polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention, (D1) is present in the first compoment (K1).

The polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention, (D1) has preferably a hydroxyl number in the range of 40 to 400 mg KOH/g, more preferably in the range of 50 to 250 mg KOH/g, even more preferably in the range of 85 to 200 mg KOH/g. The hydroxyl number is determined according to DIN53240, 2016.

The polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention, (D1) has preferably an acid number of less than 100 mg KOH/g, more preferably of less than 50 mgKOH/g, even more preferably of less than 20 mg KOH/g and most preferably of less than 15 mg KOH/g. The acid number is determined according to DIN53402, 1990. The polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention, (D) can be selected from the group consisting of (meth)acrylic polymer carrying more than one OH group, polyester carrying more than one OH group, polyether carry- ing more than one OH group, urea-formaldehyde resin carrying more than one OH group, mel- amine-formaldehyde resins carrying more than one OH group, polycarbonate carrying more than one OH group polyurethane carrying more than one OH group, and polymers of ethyleni- cally unsaturated monomers, excluding (meth)acrylic-type monomers, carrying more than one OH group.

(Meth)acrylic means either methacrylic and/or acrylic.

The (meth)acrylic polymer carrying more than one OH group can comprise monomer units de- rived from at least one (meth)acrylic monomer carrying at least one OH group, from at least one (meth)acrylic monomer carrying no OH groups, and optionally from other ethylenically unsatu- rated monomers.

Examples of (meth)acrylic monomers carrying at least one OH group are monoesters of (meth)acrylic acid with aliphatic diols, preferably Ci-io-aliphatic diols, more preferably C1-4- aliphatic diols, such as 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxypropyl acry- late, 4-hydroxybutyl methacrylate, 4-hydroxylbutyl acrylate, 6-hydroxyhexyl methacrylate and 6-hydroxyhexyl acrylate.

Examples of (meth)acrylic monomers carrying no OH group are Ci-20-alkyl (meth)acrylates such as methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate, n-butyl acrylate, n-hexyl methacrylate, n-hexyl acrylate, n-heptyl methacrylate, n-heptyl acrylate, n-octyl methacylate, n-octyl acrylate, 2-ethyl hexyl methacrylate and 2-ethylhexyl acrylate, as well as Cs-ycycloalkyl (meth)acrylates such as cyclohexyl methacrylate and cyclohexylacrylate, as well as other (meth)acrylate esters carrying no OH group such as isobomyl methacrylate and isobornyl acrylate.

Examples of C_1-20-alkyl are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n- pentyl, iso-pentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, n- heptyl, isoheptyl, n-octyl, 2-ethylhexyl, trimethylpentyl, n-nonyl, n-decyl, n-undecyl and n- dodecyl.

Examples of C_5-7-cydoalkyl are cyclopentyl, cyclohexyl and cycloheptyl.

Further examples of (meth)acrylic monomers carrying no OH group are methacrylonitrile, acry- lonitrile, methacrylic acid, acrylic acid, methacrylamide, acrylamide, N-(methoxymethyl)- methacrylamide, N-(methoxymethyl)acrylamide, N-(2-methoxyethyl)methacrylamide, N-(2-methoxyethyl)acrylamide, N-(2-methoxypropyl)methacrylamide and N-(2-methoxypropyl)- acrylamide.

Examples of other ethylenically unsaturated monomers are unsaturated C_2-8-aliphatic com- pounds such as ethylene, propylene, isobutylene, butadiene and isoprene, C_6-20-aromatic com- pounds carrying one vinyl group such as styrene, vinyl toluene, 2-n-butyl styrene, 4-n-butyl sty- rene and 4-n-decyl styrene, vinyl esters of saturated C_1-20-fatty acids such as vinyl acetate, vinyl propionate, vinyl stearate and vinyl laurate, alpha, beta -unsaturated carboxylic acids different from methacrylic acid and acrylic acid such as crotonic acid and their C_1-20-alkyl esters, nitriles and amides, ethylenic unsaturated diacids such as fumaric acid, itaconic acid and maleic acid as well as their anhydrides such as maleic anhydride, vinyl ethers of C_1-10-alcohols such as vinyl methyl ether, vinyl isobutyl ether, vinyl hexyl ether and vinyl octyl ether, vinyl amides such as N- vinyl formamide, N-vinyl pyrrolidone and N-vinyl caprolactam, as well as heteroaromatic com- pounds carrying one vinyl group such as N-vinyl imidazole.

Preferably, the polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention, (D1) is at least one (meth)acrylic polymer carrying more than one OH group.

More preferably, the polymer carrying more than one OH group, which is different from the pol- yester polyol (1) of the present invention, (D1) is a (meth)acrylic resin polymer carrying more than one OH group and comprising monomer units derived from at least one (meth)acrylic monomer carrying at least one OH group selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate,

3-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl methacrylate and

4-hydroxylbutyl acrylate.

Most preferably, the polymer carrying more than one OH group, which is different from the poly- ester polyol (1) of the present invention, (D1) is a (meth)acrylic resin polymer carrying more than one OH group and comprising monomer units derived from at least one (meth)acrylic monomer carrying at least one OH group selected from the group consisting of 2-hydroxyethyl methacry- late and 2-hydroxyethyl acrylate.

The (meth)acrylic polymer carrying more than one OH group has preferably a number average molecular weight Mn in the range of 500 to 30000 g/mol, more preferably in the range of 500 to 10000 g/mol, even more preferably in the range of 500 to 5000 g/mol. The number average mo- lecular weight is determined using gel permeation chromatography calibrated to a polystyrene standard.

The (meth)acrylic polymer carrying more than one OH group has preferably a weight average molecular weight Mw in the range of 500 to 50000 g/mol, more preferably in the range of 500 to 10000 g/mol. The weight average molecular weight is determined using gel permeation chroma- tography calibrated to a polystyrene standard.

The polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention, (D1) can be prepared by methods known in the art.

For example, (meth)acrylic polymers carrying more than one OH group comprising monomer units derived from at least one (meth)acrylic monomer carrying at least one OH group, from at least one (meth)acrylic monomer carrying no OH groups, and optionally from other ethylenically unsaturated monomers, can be prepared by radical polymerization of the corresponding mono- mers. The radical polymerization is usually performed in the presence of at least one radical initiator such as azobis(isobutyronitrile), dibenzoyl peroxide or sodium peroxodisulfate. The rad- ical polymerization can be performed, in organic solution, or in bulk polymerization. The radical polymerization can be performed in a batch process or as continuous process.

The weight ratio of the polyester polyols (1) of the present invention to the polymers carrying more than one OH group, which are different from the polyester polyols (1) of the present inven- tion, (D1) in the first component (K1) of the organic solvent-based two component coating com- position is preferably in the range of 0.01/1 to 2/1, preferably in the range of 0.1/1 to 1/1, more preferably, in the range of 0.15/1 to 0.65/1 , most preferably in the range of 0.25/1 to 0.5/1.

Component (F1) is at least one compound, oligomer or polymer carrying more than one N=C=0 group or blocked N=C=0 group.

Blocked N=C=0 group are groups that can be de-blocked to release the N=C=0 group under specific conditons, for example at elevated temperatures such as at temperatures above 110 °C. Compounds, oligomers or polymers carrying more than one blocked N=C=0 groups can be prepared, for example, by reacting the corresponding compounds, oligomers or poly- mers carrying more than one N=C=0 group with a compound carrying acidic hydrogens. Exam- ples of compounds carrying acidic hydrogens are diethyl malonate, 3,5-dimethylpyrazole and 2-butanonoxime.

The compound carrying more than one N=C=0 group or blocked N=C=0 group is preferably an aliphatic, alicyclic or aromatic compound carrying at least two N=C=0 groups or blocked N=C=0 groups, for example an aliphatic, alicyclic or aromatic compound carrying two N=C=0 groups or blocked N=C=0 groups, or an aliphatic, alicyclic or aromatic compound carrying three N=C=0 groups or blocked N=C=0 groups.

Aromatic compounds carrying at least two N=C=0 groups or blocked N=C=0 groups are com- pounds carrying at least two N=C=0 groups or blocked N=C=0 groups, wherein at least one N=C=0 group is directly attached to an aromatic ring. Alicyclic compounds carrying at least two N=C=0 groups or blocked N=C=0 groups are compounds carrying at least two N=C=0 groups or blocked N=C=0 groups, which comprise at least one alicyclic ring and wherein each N=C=0 group is not directly attached to an aromatic ring. Aliphatic compound carrying at least two N=C=0 groups or blocked N=C=0 groups are compounds carrying at least two N=C=0 groups or blocked N=C=0 groups, which comprise no alicyclic ring, and wherein each N=C=0 group is not directly attached to an aromatic ring. Preferred aliphatic, alicyclic and aromatic compounds carrying at least two N=C=0 group or blocked N=C=0 group, exclusively consist, apart from the N=C=0 groups or blocked N=C=0 groups, of carbons and hydrogens.

Examples of aliphatic compounds carrying two N=C=0 groups are tetramethylene 1 ,4- diisocyanate, pentamethylene 1,5-diisocyanate, hexamethylene 1,6-diisocyanate, octameth- ylene 1,8-diisocyanate, decamethylene 1,10-diisocyanate, dodecamethylene 1,12-diisocyanate, tetradecamethylene 1,14-diisocyanate, methyl 2,6-diisocyanatohexanoate, ethyl 2,6- diisocyanatohexanoate, trimethylhexane diisocyanate or tetramethy I hexane diisocyanate,

Examples of alicyclic compounds carrying two N=C=0 groups are 1,4-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1 ,2-diisocyanatocyclohexane, 4,4’- di(isocyanatocyclohexyl)- methane, 2,4’-di(isocyanatocyclohexyl)methane, 1-isocyanato-3,3,5-trimethyl-5-(isocyanato- methyl)cyclohexane (isophorone diisocyanate), 1,3- bis(isocyanatomethyl)cyclohexane, 1,4- bis(isocyanatomethyl)cyclohexane, 2,4- diisocyanato-1-methylcyclohexane, 2,6-diisocyanato-1- methylcyclohexane, and 3(or 4),8(or 9)-bis (isocyanatomethyl)tricyclo[5.2.1.0(2,6)]decane.

Examples of aromatic compounds carrying two N=C=0 groups are 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 2,4’-diisocya- natodiphenylmethane, 4,4’-diisocyanatodiphenylmethane, 1,3-phenylene diisocya- nate, 1,4-phenylene diisocyanate, 1-chloro-2,4-phenylene diisocyanate, 1 ,5-naphthylene diiso- cyanate, diphenylene 4,4’-diisocyanate, 4,4’-diisocyanato-3,3’-dimethylbiphenyl, 3-methyl- diphenylmethane 4,4’-diisocyanate, tetramethylxylylene diisocyanate, 1,4-diisocyanatobenzene and diphenyl ether4,4’-diisocyanate.

Examples of aliphatic compounds carrying three N=C=0 groups are 1 ,4,8-triisocyanatononane, 2’-isocyanatoethyl 2,6-diisocyanatohexanoate.

Examples of aromatic compounds carrying three N=C=0 groups are 2,4,6-triisocyanatotoluene, triphenylmethane triisocyanate and 2,4,4’-triisocyanatodiphenyl ether.

Compounds carrying more than one N=C=0 group can be prepared by methods known in the art, for example by treating the corresponding amines with phosgene.

Examples of oligomer or polymer carrying more than one N=C=0 group or blocked N=C=0 group are oligomers or polymers carrying more than one N=C=0 group or blocked N=C=0 group, which comprise at least one unit independently derived from the group consisting of ali- phatic, alicylic and aromatic compounds carrying at least two N=C=0 group. Aliphatic, alicylic or aromatic compounds carrying at least two N=C=0 groups are as defined above.

Examples of oligomers or polymers carrying more than one N=C=0 groups are also so-called “polymeric diphenyl diisocyanate”.

The N=C=0 content of the oligomers or polymers carrying more than one N=C=0 group or blocked N=C=0 group can be in the range of 1 to 60 %, more preferably in the range of 5 to 40%, even more preferably in the range of 15 to 30%, most preferably in the range of 20 to 25%.

The N=C=0 content is the weight ratio of the N=C=0 groups of the oligomer or polymer carry- ing more than one N=C=0 group to the oligomer or polymer carrying more than one N=C=0 group.

When determing the N=C=0 content, the oligomer or polymer carrying more than one N=C=0 group must be in de-blocked form. The N=C=0 content can, for example, be determined by the following method: 10 mL of a 1 N solution of n-dibutyl amine in xylene is added to 1 g of a com- pound, oligomer or polymer dissolved in 100 mL of N-methylpyrrolidone. The resulting mixture is stirred at room temperature for five minutes. Then, the resulting reaction mixture is subjected to back titration using 1 N hydrochloric acid to measure the volume of the hydrochloric acid needed for neutralizing the unreacted n-dibutyl amine. This then reveals how much mol n- dibutyl amine reacted with N=C=0 groups. The content of N=C=0 is the weight of all N=C=0 groups in 1 g of oligomer or polymer carrying more then one N=C=0 group/1 g of oligomer or polymer carrying more than one N=C=0 group. The weight of all N=C=0 groups is “mol reacted n-dibutyl amine” multiplied by the molecular weight of N=C=0, which is 42 g/mol.

Preferably, component F1 is an oligomer or polymers carrying more than one N=C=0 group or blocked N=C=0 group.

More preferably, component F1 is at least one oligomer or polymer carrying more than one N=C=0 group or blocked N=C=0 group and comprising (i) at least one unit independently de- rived from the group consisting of aliphatic and alicylic compounds carrying at least two N=C=0 groups, and (ii) at least one structural unit selected from the group consisting of uretdione, iso- cyanurate, biuret, urea, carbodiimide, uretonimine, urethane, allophanate, oxadiazinetrione and iminooxadiazinedione.

Even more preferably, component F1 is at least one oligomer or polymer carrying more than one N=C=0 group and comprising (i) at least one unit independently derived from the group consisting of aliphatic and alicylic compounds carrying at least two N=C=0 groups, and (ii) at least one isocyanurate structural unit. Most preferably, component F1 is at least one oligomer or polymer carrying more than one N=C=0 group and comprising (i) at least one unit independently derived from the group consist- ing of hexamethylene-1 ,6-diisocyanate, 4,4’- di(isocyanatocyclohexyl)methane, 2,4’- di(isocyanatocyclohexyl)methane and 1 -isocyanato-3,3,5-trimethyl-5-(isocyanatomethyl)- cyclohexane (isophorone diisocyanate), and (ii) at least one isocyanurate structural unit.

In particular, component F1 is at least one oligomer or polymer carrying more than one N=C=0 group and comprising (i) at least one unit derived from hexamethylene-1, 6-diisocyanate and (ii) at least one isocyanurate structural unit.

The molar ratio of N=C=0 groups of polyisocyanate (F1) to the OH groups of all components of the organic solvent-based two component coating composition, including polyester polyol (1) of the present invention, components D and optional additives carrying OH groups for example grinding agent Laropal A-8L is from 50-150%, preferably 80 to 120%. A ratio of 100% is also referred to as so-called “index 100”.

The organic solvent-based two-component coating composition comprises at least one organic solvent.

Suitable organic solvents are esters, ketones, amides, ethers and aromatic hydrocarbons and mixtures thereof.

Examples of esters of are ethyl acetate, butyl acetate, 1-methoxy-2-propyl acetate, 2-butoxy ethyl acetate (butyl gycol acetate), propylene glycol diacetate, ethyl 3-ethoxypropionate, 3- methoxybutyl acetate, butyldiglycol acetate and propylene carbonate. Examples of ketones are acetone, methyl ethyl ketone and methyl isobutyl ketone. Examples of amides are dimethylfor- mamide (DMF) and N-methyl pyrrolidone (NMP). Example of ethers are glycol ethers such as dipropylene glycol dimethylether, and cyclic ethers such as tetrahydrofuran and 1,4-dioxane. Examples of aromatic hydrocarbons are xylene and Solvesso® 100.

A preferred organic solvent is an ester are or mixtures thereof. A more preferred organic sol- vent is an ester of a Ci-₆-alkanoic acids with a Ci-₆-alkanol such as butyl acetate and ethyl ace- tate. A particularly preferred organic solvent is butyl acetate.

The organic solvent-based two-component coating composition, preferably, also comprises at least one catalyst.

Examples of catalysts are organic bases, organic acids, organic metal compounds and inorganic metal salts.

Examples organic bases are amines such as 1,4-diazobicyclo[2.2.2]octane (DABCO), amidine or guanidine-type compounds such as 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), N-methyl- 1,5,7-triazabicyclododecene (MTBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and N- heterocyclic carbenes such as1 ,3-bis(ditert-butyl)imidazole-2-ylidene.

Examples of organic acids are organic sulfonic acids such as methylsulfonic acid and trifluoromethylsulfonic acid, and phosphonic acids such as diphenylphosphonic acid.

Examples of organic metal compounds are organic antimony compounds, organic bismuth compound, organic germanium compounds, organic tin compounds, organic lead compounds, organic aluminium compounds, organic zinc compounds, organic mercury compounds, organic copper compounds, organic nickel compounds, organic cobalt compounds, organic manganese compounds, organic molybdenum compounds, organic vanadium compunds, organic titanium compounds, organic zirconium compounds and organic caesium compounds.

Examples of organo tin compounds are organo tin(ll) compounds such as tin(ll) diacetate, tin(ll) dioctoate, tin(ll) bis(2-ethylhexanoate) and tin(ll) dilaurate, as well as dialkyltin(IV) compounds such as dimethyltin(IV) diacetate, dibutyltin(IV) diacetate, dibutyltin(IV) dibutyrate, dibutyltin(IV) bis(2-ethylhexanoate), dibutyltin(IV) dilaurate, dibutyltin(IV) maleate, dioctyltin(IV) dilaurate and dioctyltin(IV) diacetate.

Examples of an organo zinc compounds are zinc(ll) dioctoate and zinc(ll) acetylacetonate.

An example of an organo bismuth compound is bismuth(lll) tris(neodecanoate).

Examples of organo zirconium compounds are zirconium(IV) tetrakis(acetylacetonate), zirconium (IV) tetrakis(2,4-pentandionate) and zirconium(IV) tetrakis(2,2,6,6-tetramethyl-3,5- heptanedionate).

An example of an organo iron compound is iron(lll) tris(acetylacetonate). An example of an organo titanium compound is titanium(IV) tetrakis(acetylacetonate). An example of an organo manganese compound is manganese(lll) tris(acetylacetonate). An example of an organo nickel compound is nickel(ll) bis(acetylacetonate). Examples of an organo cobalt compounds are cobalt(ll) bis(acetylacetonate) and cobalt (III) tris(acetylacetonate). Examples of organic molybdenum compounds are molybdenum(ll) bis(acetylacetonate) and molybdenum dioxide tetramethylheptadionate. Examples of an organic cesium compound is cesium propionate and cesium 2-ethylhexanoate.

Examples of inorganic metal salts are lithium molybdate, lithium tungstate and cesium phosphate.

Preferably the catalyst is an organic metal compound. More preferably, the catalyst is an organic metal compound selected from the group consisting of organic tin compounds, organic zinc compounds, organic zirconium compounds and organic bismuth compounds. Even more preferably, the catalyst is selected from the group consisting of dimethyltin(IV) diacetate, dibutyltin(IV) dibutyrate, dibutyltin(IV) bis(2-ethylhexanoate), dibutyltin(IV) dilaurate, dioctyltin(IV) dilaurate, zinc(ll) dioctoate, zirconium(IV) tetrakis(acetylacetonate), zirconium(IV) tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionate) and bismuth(lll) tris(neodecanoate). Most preferably, the catalyst is dibutyltin(IV) dilaurate.

The catalyst is usually used in an amount in the range of 50 to 10000 ppm, preferably 50 to 5000 ppm, more preferably 100 to 1000 ppm, based on the weight of all OH-group carrying components of the composition of the present invention.

The organic solvent-based two component coating composition can comprise a pigment and/or a dye.

Pigments can be organic or inorganic absorption pigments or organic or inorganic effect pig- ments.

Examples of organic absorption pigments are azo pigments, phthalocyanine pigments, quinacridone pigments, and pyrrolopyrrole pigments. Examples of inorganic absorption pigments are iron oxide pigments, titanium dioxide and carbon black.

Effect pigments are all pigments which exhibit a platelet-shaped construction and give a surface coating specific decorative color effect. The effect pigments can be pure metallic effect pigments such as aluminium, iron or copper effect pigments, interference effect pigments such as titanium dioxide-coated mica effect pigments, iron oxide-coated mica effect pigments, mixed oxide-coated mica effect pigments and metal oxide-coated aluminium effect pigments, or liquid- crystal effect pigments.

Examples of dyes are azo, azine, anthraquinone, acridine, cyanine, oxazine, polymethine, thiazine and triarylmethane dyes.

The organic solvent-based two component coating composition can comprise further additives such as defoamers, leveling agents, dispersing agents, grinding agents, light stabilizers, anti- static agents, flame retardants, thickeners, thixotropic agents, surface-active agents, viscosity modifiers, plasticizers, chelating agents, and fillers.

The additives are known in the art.

An example of a defoamer is EFKA® PB 2744. An example of a levelling agent is EFKA® WE 3050. An example of a dispersing agent is EFKA® PX 4330. An example of a grinding agent is Laropal® A-8L, a condensation product of urea and aliphatic aldehyde.

Examples of light stabilizers are UV absorbers and hindered amine light stabilizers (HALS). Examples of UV absorbers are benzotriazoles such as benzenepropanoic acid, 3-(2H- benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy ester and a-[3-[3-(2H-benzotriazol-2-yl)-5- (1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxopropyl]-u>-hydroxypoly(oxo-1,2-ethanediyl), as well as benzophenones such as 2-hydroxy-4-n-octoxy benzophenone.

Examples of hindered amine light stabilizers are 2,2,6,6-tetramethylpiperidine, 2,6-di-tert- butylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1, 2,2,6, 6-pentamethyl-4- piperidinyl) [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(1 ,2,2,6,6- pentamethyl-4-piperidinyl) sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and decanedioic acid, bis(1-octyloxy- 2,2,6,6-tetramethyl-4-piperidinyl) ester.

Examples of thickeners are hydroxymethyl cellulose and bentonite.

An example of a chelating agent is ethylenediamine tetraacetic acid.

Examples of fillers are silica gel, kieselgur, talc, calcium carbonate, kaolin, barium sulfate, magnesium silicate, aluminium silicate, siliceous earth, crystalline silicon dioxide, amorphous silica, aluminium oxide, microspheres or hollow microspheres made, for example, of glass, ceramic or polymers, urea-formaldehyde condensates, micronized polyolefin wax and micronized amide wax. Preferred fillers are siliceous earth, talc, aluminium silicate, magnesium silicate and calcium carbonate.

The organic solvent-based two-component coating composition can be prepared by mixing the first component (K1) with the second component (K2) in the presence of at least one organic solvent. At least one catalyst or further additives can be present when mixing the first compo- nent (K1) with the second component (K2), or added after mixing the first component (K1) with the second component (K2).

The flow time of the solvent-based two-component coating composition can be adjusted by ad- dition of at least one organic solvent. This organic solvent can be the organic solvent already used as organic solvent in the first component K1. The flow time can be, for example adjusted so that the flow time is in the range of 10 to 50 seconds, preferably in the range of 20 to 35 sec- onds according to DIN EN 53211,1987 using a flow cup having a 4 mm hole diameter.

In one preferred embodiment the organic solvent-based two-component coating composition is a pigmented organic solvent-based two-component coating composition comprising a) a first component (K1) comprising (i) the polyester polyol (1) of the present invention, and (ii) at least one polymer carrying more than one OH group, which is different from the polyester polyol of the present invention, (D1), b) a second component (K2) comprising (i) at least one compound, oligomer or polymer carrying more than one N=C=0 group or blocked N=C=0 group (F1), wherein the first component (K1) and/or the second component (K2) also comprises at least one organic solvent, at least one catalyst, at least one pigment, and at least one additive.

The sum of polyester polyols (1) of the present invention, polymers carrying more than one OH group, which are different from the polyester polyol of the present invention, (D1) and of compounds, oligomers or polymers carrying more than one N=C=0 group or blocked N=C=0 group (F1) preferably represents from 5 to 80 weight%, more preferably from 10 to 60 weight%, and most preferably from 20 to 45 weight% of the pigmented organic solvent-based two- component coating composition.

The polyester polyols (1) of the present invention preferably represents from 1 to 20 weight%, more preferably from 1 to 10 weight% of the pigmented organic solvent-based two-component coating composition.

The pigment preferably represents from 5 to 80 weight %, more preferably from 20 to 60 weight%, and most preferably from 30 to 40 weight% of the pigmented organic solvent-based two-component coating composition.

The organic solvent preferably represents from of 1 to 60 weight%, more preferably in the range of 5 to 45 weight%, and most preferably in the range of 15 to 35 weight% of the pigmented organic solvent-based two-component coating composition.

The additive preferably represents from 0.5 to 40 weight%, more preferably from 2 to 20 weight% and most preferably from 3 to 15 weight% of the pigmented organic solvent-based two-component coating composition.

The polyester polyol, the one polymer carrying more than one OH group, which is different from the polyester polyol of the present invention, (D1), at least one compound, oligomer or polymer carrying more than one N=C=0 group or blocked N=C=0 group (F1), the organic solvent and the catalyst, the pigment and the additive are as described above.

The pigment is preferably an inorganic absorption pigments, and more preferably titanium dioxide.

The additive is preferably selected from the group consisting of defoamer agent, levelling agent, dispersing agent and grinding agent.

The pigmented organic solvent-based two-component coating composition can be prepared by preparing the first component (K1) by mixing (i) the polyester polyol (1) of the present invention, and (ii) the at least one polymer carrying more than one OH group, which is different from the polyester polyol (1) of the present invention, (D1), adding organic solvent, catalyst, pigment paste and additives such as defoaming agents and levelling agents to the first component (K1), and then adding the second component (K2).

The pigment paste usually comprises the pigment, organic solvent and additives such as dis- persing agents and grinding agents and can be prepared by stirring the ingredients at high speed in the presence of glass beads, followed by removal of the glass beads.

The flow time of the pigmented organic solvent-based two-component coating composition can be adjusted by addition of at least one organic solvent. This organic solvent can be the organic solvent already used as organic solvent in the first component K1. The flow time can be, for example adjusted so that the flow time is in the range of 10 to 50 seconds, preferably in the range of 15 to 35 seconds according to DIN EN 53211,1987 using a flow cup having a 4 mm hole diameter

Also part of the present invention is an organic solvent-based two-component coating composi- tion comprising a) a first component (K3) comprising

(i) a polyester polyol (6) carrying at least one group selected from the group consisting of

wherein

R³ is selected from the group consisting of -CH₂-CH₂-O-C(=O)-CH=CH₂ and -CH₂CH₂-O- C(=O)-C(CH₃)=CH₂ and

(ii) optionally at least one polymer carrying more than one OH group, which is different from the polyester polyol (6) (D2). and b) a second component (K4) comprising (i) at least one compound, oligomer or polymer carry- ing more than one N=C=0 group or blocked N=C=0 group (F2).

The definition and preferences of D2 are the same as given above for D1.

The definition and preferences of F2 are the same as given above for F1.

The polyester polyol (6) carrying at least one group selected from the group consisting of

wherein

R³ is selected from the group consisting of -CH₂-CH₂-O-C(=O)-CH=CH₂ and -CH₂CH₂-O-C(=O)- C(CH₃)=CH_2, preferably comprises units derived from a) at least one component carrying at least one COOH group or a derivative thereof (A), where- in component A comprises

The definitions and preferences of A, A1 , B, B1 and B2 are the same as given above for polyes- ter polyol (1).

Also part of the present invention is a substrate coated with the organic solvent-based two com- ponent compositions of the present invention.

Examples of substrates are wood, wood veneer, paper, cardboard, paperboard, textile, film, leather, nonwoven, plastics surfaces, glass, ceramic, mineral building materials, such as mold- ed cement blocks and fiber-cement slabs, and metals, which in each case are optionally pre- coated or pretreated. A preferred substrate is metal, which is optionally precoated or pretreated.

Also part of the present invention is a process for coating a substrate with the organic solvent- based two component compositions of the present invention which comprises the step of apply- ing the organic solvent-based two component composition to the substrate.

The organic solvent-based two-component coating composition of the present invention can be applied to the substrate by methods common in the art such as by draw down bar, spraying, troweling, knifecoating, brushing, rolling, rollercoating, flowcoating and laminating.

Following the application of the organic solvent-based two-component coating composition of the invention, the composition of the present invention is cured at a temperature in the range of 15 to 140 °C, preferably in the range of 20 to 100 °C.

The thickness of the “wet” layer formed from the organic solvent-based two-component coating composition of the present invention is usually in the range of 20 to 5000 pm, preferably in the range of 50 to 500 pm, more preferably in the range of 100 to 250 pm. After curing, the thick- ness of the layer is usually in the range of 10 to 500 pm, preferably in the range of 15 to 200 pm, more preferably in the range of 20 to 100 pm.

Substrates coated with the organic solvent-based two-component coating composition of the present invention can, for example, be part of automotives, large vehicles, aircrafts, utility vehicles in agriculture and construction, bridges, buildings, power masts, tanks, containers, pipelines, power stations, chemical plants, ships, cranes, posts, sheet piling, valves, pipes, fittings, flanges, couplings, halls, roofs, furniture, windows, doors, woodblock flooring, cans, coils and floors.

The organic solvent-based two-component coating composition of the present invention can, for example, be used as pigmented organic solvent-based two-component coating composition

Also part of the present invention is the use of the compositions of the present invention in coating composition suitable for preparing coatings of automotives, large vehicles and of utility vehicles in agriculture and construction.

The polyester polyols of the present invention are advantageous in that the polyester polyols are suitable for use in organic solvent-based two-component coating compositions yielding a polyurethane coating, which coating compositions show a good drying behavior, in particular a short cotton wool drying time and a short sand drying time. The polyester polyols of the present invention are also advantageous in that the polyester poly- ols are suitable for use in organic solvent-based two-component coating compositions yielding a polyurethane coating, which coating compositions show an acceptable solid content.

The polyester polyols of the present invention are also advantageous in that the polyester poly- ols are suitable for use in organic solvent-based two-component coating compositions yielding a polyurethane coating, which coatings show improved mechanical properties such as a high pendulum hardness.

Examples

Description of Test Methods

The weight average molecular weight Mw and number average molecular weight Mn were de- termined using gel permeation chromatography calibrated to a polystyrene standard.

The glass transition temperature (Tg) was determined using differential scanning calorimetry.

The hydroxyl number was determined according to DIN53240, 2016.

The acid number was determined according to DIN53402, 1990.

The solid content of solutions comprising polyester polyol were measured using a moisture ana- lyzer (Mettler Toledo HB43-S Moisture Analyzer) at 160 °C until constant mass was reached.

The solid content of white pigmented coating compositions comprising the polyester polyol solu- tions were calculated based on the measured solid content of the polyester polyol solutions.

The viscosity was determined using a cone plate viscosimeter set to a shear rate of 100 s^'1 at 23 °C.

Cotton wool drying time: The coating composition was applied with a draw down bar on a glass plate yielding a wet film thickness of 150 pm. After film application, a frayed cotton wool was swept without pressure across the surface of the coating every 5 to 10 minutes. At the begin- ning, cotton fibers were sticking to the coating. The time when no fibers remained attached to the coating, is referred to as the cotton wool drying time.

Sand drying time: The coating composition was applied with a draw down bar on two glass plates (double determination) yielding a wet film thickness of 150 pm. The glass plates with the wet film were quickly placed under a cylindrical funnel that moves at constant velocity of 1 cm per hour over the wet film. Along the way, sand trickles out of the funnel on the film. When the film is not surface-cured, the film is still tacky and the sand sticks to it. When the film is surface- cured, the sand can be wiped away with a brush. The length (1cm length refers to 1 hour) of the sand path sticking to the coating is referred to as sand drying time.

Pendulum hardness fosc.1: The coating composition was applied with a draw down bar having a gap of 150 mΐti on a 4 mm thick glass plate, which has been cleaned with acetone before, yield- ing a wet film. The pendulum hardness was measured according to DIN EN ISO 1522:2006 using the Konig pendulum.

Example 1

Preparation of a monoisocyanate (2-la/2-l^'a) from isoborneol and isophorone diisocyanate hav- ing a ratio mol isoborneol/ mol isophorone diiscocyanate of 1/1

Isophorone diisocyanate (531.3 g, 2.39 mol) was added to a flask under nitrogen atmosphere, followed by addition of isoborneol (368.7 g, 2.39 mol). Butylacetate (286 g) was added. The mixture was then stirred and heated to 60 °C until a clear solution was obtained. Then TIB-Kat 616 (tin neodecanoate) (720 mg, 800 ppm) was introduced. A very light exothermic reaction was observed. The mixture was stirred for an additional 3 to 4 hours at 65 °C and the reaction was followed by NCO-titration. The reaction was stopped when the targeted NCO content of 7.78% was reached.

Example 2

Preparation of polyester polyol (3a)

Cyclohexane-1, 2-dicarboxylic acid anhydride (mixture of isomers) (HHPA) and 1,1,1 -trimethylol- propane (TMP) were mixed in a molar ratio of 1:1 and slowly heated to 160 °C under a steady stream of nitrogen. When the reaction mixture reached 135 °C, an exothermic reaction was observed. The reaction mixture was kept at 160 °C for 30 min, and then heated to 180 °C. Wa- ter was removed by distillation. The reaction was monitored by the titration of the acid number and cooled down to 80 °C when the desired value was reached. Butyl acetate was added to the melt to yield a solution comprising a polyester polyol (3a) with a solid content as indicated in table 1. The solid content, the hydroxyl number, the acid number, the glass temperature (Tg) the number average molecular weight (Mn), the weight average molecular weight (Mw) of the polyester polyol (3a) and the viscosity of the solution of the polyester polyol (3a) were deter- mined according to the methods described in the section above titled “Description of test meth- ods” and are also shown in table 1. Example 3

Preparation of polyesters 1a, 1b, 1c, 1d and 1e, respectively, carrying at least one isobornyl group, obtainable from monoisocyanate (2-la/2-l^'a) and polyester polyol (3a)

The solution of polyester polyol (3a) of example 2 was added to the solution of monoisocyanatet (2-la/2-l^'a) of example 1. The amounts of solution of monoisocyanate (2-la/2-l^'a) of example 1 and solution of polyester polyol (3a) of example 2 were chosen so that the ratio [mol NCO groups monoisocyanate (2-la/2-l^'a)]/[mol OH groups polyester (3a)] was as indicated in table 1. The polyester polyol (3a) and the monoisocyanate (2-la/2-l'a) were allowed to react at 65 °C for 10 hours. After 10 hours no NCO bands could be detected by IR spectroscopy anymore. The hydroxyl number, the acid number, the glass temperature (Tg) the number average molecular weight (Mn) and the weight average molecular weight (Mw) of polyster polyol 1a, 1b, 1c, 1d and 1e, respectively, and the solid content and the viscosity of the solution of polyster polyol 1a, 1b, 1c, 1d and 1e, respectively, were determined according to the methods described in the section above titled “Description of test methods” and are also shown in table 1.

Table 1.

Example 4

Preparation of a white pigment paste 20 g Laropal® A-8L (a grinding resin, 80% solution of a condensation product of urea and ali- phatic aldehyde in 1-methoxy-2-propyl acetate, hydroxyl number: 90 mg KOH/g, available from BASF), 3.0 g 1-methoxy-2-propyl acetate and 3.0 g EFKA® PX 4330, a high molecular weight dispersing agent available from BASF, were mixed using a lab stirrer. The speed of the stirrer was slowly increased to 4000 rpm and kept at that speed for 5 minutes. 74.0 g Kronos® 2310, a white pigment with a white pigment index 6, was slowly added to the mixture under stirring. The speed of the stirrer was slowly increased to 5000 rpm and kept at that speed for 10 minutes. Then, the mixture was placed in a grinding mill. 150 g glass beads with a diameter in the range from 0.75 to 1 mm were added and the mixture was grinded at a speed of 5500 rpm for 30 minutes. Afterwards, the white pigment paste was separated from the glass beads using com- pressed air.

Example 5

Preparation of a white pigmented coating composition comprising the polyester polyols 3a, 1a, 1b, 1c, 1d and 1e, respectively, and application of the coating compositions on a glass plates

0.647 g of a 1 wt% solution of dibutyltin(IV) dilaurate (catalyst) in butyl acetate was added in a 100 ml_ glass jar. Then, 0.388 g EFKA® PB 2744 (a defoaming agent available from BASF) was added, followed by 0.525 g EFKA® WE 3050 (a levelling agent available from BASF).

Then, 18 g of of Setalux® 1907 BA-75 (a 75 weight% solution of an acrylic polyol with 4.5% OH groups calculated on non-volatiles and available from Allnex in butyl acetate) was combined with the amount of the solution of polyester polyols 3a of example 2, 1 a of example 3, 1 b of ex- ample 3, 1c of example 3, 1d of example 3 and 1e of example 3, respectively, containing 4.5 g solids, and the obtained mixture comprising the acrylic polyol and polyester polyol was added to the mixture above comprising catalyst, defoaming agent and levelling agent.

49.10 g of the white pigment paste of example 4 was added to the mixture. The mixture was stored for 16 h. Then, 10 g butyl acetate was added, and the mixture was stirred using a lab stirrer with a 35 mm disc at a speed of 750 rpm for 5 minutes.

Basonat® HI 2000 NG (solvent-free, aliphatic polyisocyanate) at an index of 100 (with respect to the OH groups of Setalux® 1907 BA-75, polyester polyol, and Laropal® A-8L) was added to the mixture. The mixture was stirred using a lab stirrer with a 35 mm disc at a speed of 750 rpm for 10 minutes. Subsequently, butyl acetate was added in an amount that the viscosity meas- ured with a cone plate viscosimeter corresponds to 200 mPa X s. After waiting for 10 min, the pigmented coating composition was ready to use.

After cleaning glass substrates properly with acetone, the pigmented coating compositions were applied with a draw down bar with a wet film thickness of 200 pm. The dry film thickness was approximately 60 pm. The solid content, the cotton wool drying time, the sand drying time and the pendulum hardness [osc.] of the white pigmented coating compositions comprising polyester polyols 3a, 1a, 1b, 1c, 1d and 1e, respectively, were determined as described above in the section titled “Description of Test Methods” and are shown in table 2.

Table 2. ¹Pendulum Hardness.

Table 2 shows that inventive white pigmented organic solvent-based two-component coating compositions comprising inventive polyester polyol 1a, 1b, 1c, 1d and 1e respectively, carrying at least one isobornyl group show a shorter cotton wool drying time and sand drying time than comparative white pigmented organic solvent-based two-component coating compositions comprising polyester polyol 3a (carrying no isobornyl group). Table 2 also shows that inventive white pigmented organic solvent-based two-component coating compositions comprising poly- ester polyol 1a, 1b, 1c, 1d and 1e respectively, carrying at least one isobornyl group have a higher pendulum hardness after 1 day and 7 days at room temperature and after 7 days at room temperature followed by 15 h at 60 °C than comparative white pigmented organic solvent- based two-component coating compositions comprising polyester polyol 3a (carrying no isobornyl group). At the same time the inventive white pigmented organic solvent-based two- component coating compositions comprising polyester polyol 1a, 1b, 1c, 1d and 1e respective- ly, have a comparable solid content than the white pigmented organic solvent-based two- component coating compositions comprising comparative polyester polyol 3a.

Example 6

Preparation of a monoisocyanate (2-lb/2-l^'b) from menthol and isophorone diisocyanate having a ratio mol menthol/mol isophorone diiscocyanate of 1/1

Melted menthol (109,39 g, 0.7 mol) was added to a homogenized mixture of isophorone diiso- cyanate (155.58 g, 0.7 mol), butylacetate (88.32 g) and TIB-Kat 616 (tin neodecanoate) (210 mg) over 30 minutes. After the addition, the reaction mixture was stirred without heating for 30 minutes and then at 60 °C for 2.5 hours. The obtained solution comprising monoisocyanate (2- lb/2-l^'b) had an NCO content of 8.5% and a solid content of 75%.

Example 7

Preparation of polyesters 1f carrying at least one menthyl group, obtainable from monoisocya- nate (2-lb/2-l^'b) and polyester polyol (3a)

A solution of polyester polyol (3a) in butyl acetate with a solid content of 75% by weight was prepared in analogy to example 2. The solution of monoisocyanatet (2-lb/2-l^'b) of example 6 (242.9 g) was added to the 75% by weight solution of polyester polyol (3a) in butyl acetate (266.67 g) heated to 60 °C. The ratio [mol NCO groups monoisocyanate (2-lb/2-l^'b)]/[mol OH groups polyester (3a)] was 50%. The polyester polyol (3a) and the monoisocyanate (2-lb/2-l^'b) were allowed to react at 60 °C for 40 hours. After 40 hours, no NCO bands could be detected by IR spectroscopy anymore. The obtained solution comprising polyester (1f) was diluted with 96 g butyl actetate.

The hydroxyl number, the acid number, the glass temperature (Tg) the number average mo- lecular weight (Mn) and the weight average molecular weight (Mw) of polyester polyol 1f and the solid content and the viscosity of the solution of polyester polyol 1f was determined accord- ing to the methods described in the section above titled “Description of test methods” and are also shown in table 3.

Ta ble 3.

Claims

1. A polyester polyol (1 ) carrying at least one group selected from the group consisting of

wherein

2. The polyester polyol (1) of claim 1 carrying at least one group selected from the group con- sisting of

wherein

R¹ and R² are indenpendently and at each occurrence a residue comprising 1 to 20 carbon at- oms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH₂ wherein the polyester polyol comprises units derived from a) at least one component carrying at least one COOH group or a derivative thereof (A), where- in component A comprises

3. The polyester polyol (1) of claim 2, wherein compound A1 is at least one aliphatic or alicyclic compound carrying two COOH groups or a derivative thereof.

4. The polyester polyol (1) of claim 2, wherein B1 is a compound or oligomer carrying three OH groups and no COOH group.

5. The polyester polyol of any of claims 1 to 4, wherein the polyester polyol carries at least one group selected from the group consisting of

wherein

R¹ and R² are indenpendently and at each occurrence a residue comprising 1 to 20 carbon at- oms, with the proviso that R¹ is not -CH₂-CH₂-O-C(=O)-CH=CH₂ or -CH₂CH₂-O-C(=O)-C(CH₃)=CH_2.

6. The polyester of any of claims 1 to 5, wherein R¹ and R² are independently a residue com- prising 1 to 20 carbon atoms, but not comprising at least one -O-C(=O)-CH=CH₂ or -O-C(=O)- C(CH₃)=CH₂ group.

7. The polyester of any of claims 1 to 5, wherein R¹ and R² are independently a residue selected from the group consisting of C_3-12-cycloalkyl, C_4-12-cycloalkenyl, C_6-14-bicyclic system and C_9-20- tricyclic system, wherein C_3-12-cydoalkyl, C_4-12-cycloalkenyl, C_6-14-bicyclic system, C_9-20-tricyclic system can be independently substituted with one or more substitutent selected from the group consisting of Ci-₆-alkyl, cyclopentyl and cyclohexyl, provided the overall number of carbon at- oms of R¹ and R² each is maximum 20.

8. The polyester of any of claim 1 to 5, wherein R¹ and R² are independently a residue selected from the group consisting of C_3-12-cycloalkyl and C_6-14-bicyclic system, wherein C_3-12-cycloalkyl and C_6-14-bicyclic system can be independently substituted with one or more Ci-₆-alkyl, provided the overall number of carbon atoms of R¹ and R² each is maximum 20.

9. The polyester polyols of any of claims 1 to 5, wherein R¹ is selected from the group consisting of formulae

10. The polyester polyol (1) of any of claims 1 to 5, wherein R² is of formula

11. The polyester polyol (1) of any of claims 1 to 10, wherein the polyester polyol (1) is hyper- branched.

12. The polyester polyol (1) of any of claims 1 to 11 , wherein the polyester polyol has a hydroxyl number in the range of 30 to 400 mg KOH/g.

13. A solution comprising at least one polyester polyol (1) of any of claims 1 to 12 and at least one organic solvent.

14. A process for the preparation of the polyester polyol (1) of claim 1 carrying at least one group selected from the group consisting of

with ii) at least one polyester polyol (3), wherein

15. The process of claim 14, wherein the ratio of mol NCO groups of all monoisocyanates (2)/mol OH groups of all polyester polyol (3) is preferably in the range of from 0.01/1.0 to

0.95/1.0.

16. A monoisocyanate (2) selected from the group consisting of

wherein

17. An organic solvent-based two-component coating composition comprising a) a first component (K1) comprising (i) the polyester polyol (1) of any of claims 1 to 12 carrying at least one group selected from the group consisting of

wherein

18. An organic solvent-based two-component coating composition comprising a) a first component (K3) comprising

wherein

(ii) optionally at least one polymer carrying more than one OH group, which is different from the polyester polyol (6) (D2) and b) a second component (K4) comprising (i) at least one compound, oligomer or polymer carry- ing more than one N=C=0 group or blocked N=C=0 group (F2).

19. A substrate coated with the organic solvent-based two component coating compositions of any of claims 17 or 18.