DE102004054447A1 - Preparation of polyester polyacrylate-graft polymer dispersion with co-solvent, useful to prepare e.g. clear lacquers, comprises preparing a copolymer of vinyl monomers by radical polymerization and dispersing the copolymer in water - Google Patents

Abstract

Preparation of aqueous, hydroxy functionalized polyester polyacrylate-graft polymer dispersions (I) (with a co-solvent content of 0-5 wt.%) comprises preparing a copolymer of vinyl monomers and dispersing the obtained copolymer in water before or after the addition of a neutralizing agent. Preparation of aqueous, hydroxy functionalized polyester polyacrylate-graft polymer dispersions (I) (with a co-solvent content of 0-5 wt.%) comprises preparing a copolymer (by polymerization of a mixture to radical copolymerization of more enabled vinyl monomers (hydroxyl group free (meth)acrylic acid ester (a1) optionally in mixture with vinylaromate; hydroxy functionalized vinyl monomers and/or hydroxy functionalized (meth)acrylic acid ester (a2); (a3) ionic and/or potentially ionic, to radical copolymerization monomers or (a4) the combination of above compounds to radical copolymerization monomers) in the presence of one or more polyester polyol (b) (having a hydroxyl number of 10-500 mg potassium hydroxide (KOH)/g substance and an acid number of greater than 0.5 to less than or equal to 30 mg KOH/g substance and a double bond content (as C=C with a molecular weight of 24) of 0.1-5%) and hydroxy functionalized ester group (c) of formula (1)) and dispersing the obtained copolymer in water before or after the addition of a neutralizing agent. R1 : 1-18C aliphatic, araliphatic or aromatic residue; R2 : H or CH3; R3, R4 : 1-7C aliphatic; and n : 1-4. Independent claims are also included for: (1) (I) obtained by the above method; (2) an aqueous coating agent comprising (I); and (3) a multi-layer structure with a coating or clear lacquer layer as an uppermost coating, which is obtained by hardening (I). [Image].

Description

The Invention relates to aqueous Polyesterpolyacrylate dispersions with low solvent content based on vinyl monomer grafted polyester as well as of reactive diluents with hydroxyfunctional ester groups, a process for their preparation as well as watery Coating compositions based thereon and their use as paints.

Out The prior art discloses that in coating systems dilutable Binders are used on a copolymer basis. These contain however, usually emulsifiers for stabilization and / or larger proportions organic cosolvent. It is usually the case that the emulsifiers have the properties the paints or coatings, e.g. Water resistance, film optics (Gloss), pigmentability influence negatively.

The Use of larger quantities organic solvent is from ecological establish undesirable, However, usually unavoidable, since in the Polymerisatheter sufficient stirrability and heat dissipation the reaction mixture guaranteed have to be. additionally to lead organic solvents in aqueous Coating agents to advantageous effects, such as to an improved storage stability and pigment wetting, better film optics and a better Course.

on the other hand is an afterthought Reduction of solvents from copolymers or dispersions with high equipment and energetic effort, so that need for aqueous Polymerisatdispersionen consists in the preparation of the use organic solvent can largely be dispensed without causing deterioration the performance characteristics occurs.

copolymer dispersions, which are caused by a chemical reaction, e.g. with an aminoplast resin, a blocked polyisocyanate or a polyisocyanate are cured need to a certain amount of reactive groups, e.g. hydroxy groups, contain. These groups are usually co-used hydroxy-functional (meth) acrylic ester in the copolymerization introduced into the copolymer. These raw materials are, however, in the Comparison to the non-functional (meth) acrylic acid esters or also to styrene, very expensive. In addition, must often also larger quantities used in comparison with organically dissolved copolymers to get through a greater density of networking to compensate for the hydrophilicity of the paint films.

In DE-A 39 10829 are thermosetting coating agents described on Polyesterpolyacrylatbasis containing a solvent content between 5 and 20% by weight, based on the application-ready coating composition exhibit. As preferred solvents are water-miscible alcohols, ketones or glycol ethers or but also not called water-miscible solvents. Because the disclosed solvents not be incorporated into the coating, these will be during the Processing of the coating system as VOC (Volatile Organic Compound) released again. The mentioned, semi-volatiles Glycol derivatives remain partly in the coating and can their Properties deteriorate.

a another way to prepare hydroxy-functional copolymer secondary dispersions, the use of solvents is largely avoided in the polymerization, in EP-A 0 758,007. There are the commonly used solvents completely or partially replaced by hydroxy-functional polyether. The hydroxy-functional polyethers remain as reactive diluents in the secondary dispersion and react at the later Crosslinking with isocyanates or blocked isocyanates with formation of urethane from. As a disadvantage of these products, however, proves their poor consistency, in particular the weathering resistance.

In GB-A-2 078 766 describes a way, the solvent content in paints while to reduce the paint production. This will be solvent-containing Binders with pigments and additives commonly used in the paint industry made using various reactive diluents. The reactive diluents are they are reaction products of glycidyl esters with hydroxyl or carboxyl-containing compounds. The disadvantage of the GB-A 2 078 766 described in which, despite the use of the reactive diluent, high solvent content, since introduced by the binder considerable amounts of a Colösers become. In Example I of GB-A 2 078 766, e.g. a binder with a solvent content used of 35 wt .-%.

task The present invention thus consisted in the provision of Coplymerisatdispersionen based on polyester-polyacrylates, which are without the use of emulsifiers or larger amounts of organic solvents make and coatings with very good mechanical and optical properties.

It has now been found that from aqueous Copolymer dispersions based on carboxylate- and hydroxy-functional, vinyl monomer-grafted polyesters having a solvent content of less than 5% by weight on the dispersion, paint films produced with a high level of resistance can be when doing reaction products of glycidyl esters of aliphatic carboxylic acids with aliphatic, araliphatic or aromatic carboxylic acids as reactive be used.

• A) einer Mischung zur radikalischen Copolymerisation befähigter Vinylmonomeren A1) bis A4) in Gegenwart
• B) eines oder mehrerer Polyesterpolyol(en) mit einer Hydroxylzahl von 10 bis 500, bevorzugt 80 bis 350 mg KOH/g Substanz und einer Säurezahl von >0,5 bis ≤30, bevorzugt ≥1 bis ≤8 mg KOH/g Substanz und einem Doppelbindungsgehalt (berechnet als C=C, Molgewicht 24) von 0,1 bis 5,0 %, bevorzugt von 0,2 bis 3,0 % und besonders bevorzugt von 0,5 bis 2,0 %, sowie
• C) einer oder mehrerer Verbindung(en) der allgemeinen Formel (I)
  
  in welcher R¹ ein aliphatischer, araliphatischer oder aromatischer Rest mit 1 bis 18, bevorzugt 2 bis 10, besonders bevorzugt 4 bis 6 Kohlenstoffatomen ist, R² H oder CH₃, bevorzugt CH₃ ist, R³/R⁴ gleiche oder unterschiedliche aliphatische Reste mit 1 bis 7, bevorzugt 2 bis 5 Kohlenstoffatomen sind und n 1 bis 4, bevorzugt 2 ist, hergestellt wird und das so erhaltene Copolymerisat (P) anschließend in einem zweiten Schritt vor oder nach Zugabe eines Neutralisationsmittels in Wasser dispergiert wird.

The present invention thus provides a process for preparing aqueous, hydroxy-functional polyester-polyacrylate graft polymer dispersions having a content of cosolvents of from 0 to 5% by weight, preferably from 1 to 3% by weight, based on the dispersion characterized in that in a first step, a copolymer (P) by polymerization

• A) a mixture for free-radical copolymerization capable vinyl monomers A1) to A4) in the presence
• B) one or more polyester polyol (s) having a hydroxyl number of 10 to 500, preferably 80 to 350 mg KOH / g substance and an acid number of> 0.5 to ≤30, preferably ≥1 to ≤8 mg KOH / g substance and a double bond content (calculated as C = C, molecular weight 24) of 0.1 to 5.0%, preferably from 0.2 to 3.0% and particularly preferably from 0.5 to 2.0%, and
• C) one or more compound (s) of the general formula (I)
  
  in which R ^{1 is} an aliphatic, araliphatic or aromatic radical having 1 to 18, preferably 2 to 10, particularly preferably 4 to 6 carbon atoms, R ^{2 is} H or CH ₃ , preferably CH ₃ , R ³ / R ^{4 are} identical or different aliphatic Radicals having 1 to 7, preferably 2 to 5 carbon atoms and n is 1 to 4, preferably 2, and the resulting copolymer (P) is then dispersed in a second step before or after addition of a neutralizing agent in water.

object The present invention also relates to aqueous polyester-polyacrylate graft polymer dispersions available according to the method of the invention.

• A1) OH-gruppenfreie (Meth)acrylsäureester, gegebenenfalls in Mischung mit Vinylaromaten,
• A2) hydroxyfunktionelle Vinylmonomere und/oder hydroxyfunktionelle (Meth)acrylsäureester,
• A3) ionische und/oder potenziell ionische, zur radikalischen Copolymerisation befähigte Monomere sowie
• A4) weitere, von den Verbindungen der Komponenten A1) bis A3) verschiedene, zur radikalischen Copolymerisation befähigte Monomere.

Suitable vinyl monomer mixtures A) comprise building blocks selected from the group of the compounds:

• A1) OH-free (meth) acrylates, optionally mixed with vinyl aromatics,
• A2) hydroxy-functional vinyl monomers and / or hydroxy-functional (meth) acrylic esters,
• A3) ionic and / or potentially ionic monomers capable of radical copolymerization, and
• A4) further, different from the compounds of components A1) to A3), capable of radical copolymerization monomers.

When Monomers of component A1) are acrylates and methacrylates (im hereinafter referred to as (meth) acrylates) having 1 to 18 carbon atoms used in the alcohol part of the ester group. This alcohol part can be linear, branched or cycloaliphatic.

For example, suitable as monomers of component A1) are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, the isomeric pentyl, hexyl, octyl, dodecyl, Hexadecyl, octadecyl or cyclohexyl, trimethylcyclohexyl and isobornyl (meth) acrylates. Further, as A1) also Acetoacetoxye methyl methacrylate, acrylamide, diacetoneacrylamide, acrylonitrile, styrene, vinyl ethers, methacrylonitrile, vinyl acetates, optionally substituted styrenes and vinyltoluenes.

Prefers are methyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, Cyclohexyl and Isobornyl (meth) acrylates and styrene.

Also possible and preferred is the use of any mixtures of the above mentioned compounds A1).

When Component A2) are ethylenically unsaturated, hydroxyl-containing Suitable monomers, such as the hydroxyalkyl esters of unsaturated Carboxylic acids, preferably hydroxyalkyl (meth) acrylates having 2 to 12, preferably 2 to 6 carbon atoms in the hydroxyalkyl radical. Preferred compounds are 2-hydroxyethyl (meth) acrylate, the isomeric hydroxypropyl (meth) acrylates, 2-, 3- and 4-hydroxybutyl (meth) acrylates, the isomeric hydroxyhexyl (meth) acrylates and 1,4-cyclohexanedimethanol monomethacrylate.

Likewise suitable are alkylene oxide-modified or chain-extended, polymerizable hydroxy-functional monomers having a number-average molecular weight ≦ 3000 g / mol, preferably ≦ 700 g / mol. As alkylene oxides are preferably used for this purpose, ethylene, propylene or butylene oxide individually or in mixtures. As examples may be mentioned Bisomer ^® PEA3 (polyethylene glycol monoacrylate; 3 ethylene oxide units), Bisomer ^® PEM 6 LD (polyethylene glycol monomethacrylate; 6 ethylene oxide units), Bisomer PPM 63 E (Polyethylenglykolmonomethacrylate; 6 propylene oxide units and 3 terminal ethylene oxide units) or Bisomer ^® PEM 63 P (Polyethylenglykolmonomethacrylate; 6 Ethylene oxide units and 3 terminal propylene oxide units) from Degussa AG (Darmstadt, Germany).

Furthermore, the addition of polymerizable, nonionic hydrophilicizing alkoxypolyethylene glycol (meth) acrylates having number average molecular weights (Mn) of 430 to 2500 g / mol is suitable. Are as Beipiele here called Bisomer ^® MPEG 350 MA (Mn = 430 g / mol), 550 MA (Mn = 628 g / mol), S 7 W (Mn = 818 g / mol), S 10 W (Mn = 1080 g / mol) and S 20 W (Mn = 2080 g / mol) from Degussa AG (Darmstadt, Germany).

By ionic or potentially ionic hydrophilicizing compounds A3) is meant all compounds which have at least one radical-capable group and at least one functionality such as -COOY, -SO ₃ Y, -PO (OY) ₂ (Y, for example = H, NH ₄ ⁺ , metal cation), -NR ₂ or -NR ₃ ⁺ (R = H, alkyl, aryl, radicals R may be the same or different from each other in a molecule) which, when interacting with aqueous media, have a pH dependent Dissociation equilibrium and can be charged in this way negative, positive or neutral.

Ionian and / or potentially ionic, for radical copolymerization enabled Monomers of component A3) are preferably olefinically unsaturated monomers with carboxylic acid or carboxylic acid anhydride groups, such as. Acrylic acid, Methacrylic acid, β-carboxyethyl acrylate, crotonic, fumaric acid, maleic anhydride, itaconic or monoalkyl esters of dibasic acids or anhydrides, e.g. Maleic acid monoalkyl suitable, particularly preferred are acrylic acid and / or methacrylic acid.

Further suitable as compounds of component A3) are also unsaturated, radically polymerizable compounds with phosphate or phosphonate or sulfonic acid or sulfonate groups, e.g. in WO-A 00/39181 (page 8 Z. 13-S. 9 Z. 19). Within the group of phosphate or phosphonate or sulfonic acid or sulfonate-containing components is 2-acrylamido-2-methylpropanesulfonic a preferred component.

Possibly can also other, from A1) to A3) different, to the radical Copolymerization enabled Monomers are used as compounds of component A4). This can for example, di- or higher-functional (Meth) acrylate monomers and / or vinyl monomers, e.g. Ethanediol di (meth) acrylate, Hexanediol di (meth) acrylate, 1,4-, 1,3-butanediol dimethacrylate, di-, Tri- and oligoethylene glycol dimethacrylates, polypropylene glycol dimethacrylates, Polytetramethylene glycol dimethacrylate or divinylbenzene.

Prefers the hydrophilization of the copolymers (P) is carried out only by ionic and / or potentially ionic groups. Particularly preferred the hydrophilization by anionic and / or potentially anionic Groups.

The proportions the structural components A1) to A4) are generally chosen so that the copolymer (P) has an OH number of 12 to 350 mg KOH / g, preferred from 20 to 200 mg KOH / g, and more preferably from 50 to 150 mg KOH / g solid and an acid number from 5 to 80 mg KOH / g, preferably from 10 to 35, more preferably from 15 to 30 mg KOH / g solids.

• B1) aliphatische, gesättigte und/oder aromatische Mono-, Di-, Tri- oder Tetracarbonsäuren oder deren Anhydride,
• B2) ungesättigte Di und/oder Polyole,
• B3) di- und/oder höherfunktionelle Alkohole,
• B4) einwertige Alkohole,
• B5) Hydroxycarbonsäuren, Lactone, Aminoalkohole und/oder Aminocarbonsäuren und
• B6) (cyclo)aliphatische, olefinische ungesättigte Mono- oder Dicarbonsäuren

hergestellt.Suitable polyester polyols B) are obtained by a known polycondensation of the building blocks selected from the group of compounds:

• B1) aliphatic, saturated and / or aromatic mono-, di-, tri- or tetracarboxylic acids or their anhydrides,
• B2) unsaturated di and / or polyols,
• B3) di- and / or higher-functional alcohols,
• B4) monohydric alcohols,
• B5) hydroxycarboxylic acids, lactones, amino alcohols and / or aminocarboxylic acids and
• B6) (cyclo) aliphatic, olefinic unsaturated mono- or dicarboxylic acids

produced.

When suitable carboxylic acids B1) come monocarboxylic acids such as. benzoic acid, cyclohexane, 2-ethylhexanoic acid, caproic, caprylic, Capric acid, Lauric acid, natural and synthetic fatty acids, as dicarboxylic acids and / or anhydrides e.g. Phthalic acid, phthalic anhydride, isophthalic acid, hexahydrophthalic, anhydride, Succinic acid, succinic anhydride, adipic acid, dodecanedioic, hydrogenated dimer fatty acids and as higher functional carboxylic acids or anhydrides e.g. trimellitic and trimellitic anhydride and mixtures of these compounds in question. Preference is given to dicarboxylic acids and Dicarboxylic. Particular preference is given to cyclic dicarboxylic acids such as phthalic acid, phthalic anhydride, isophthalic acid, hexahydrophthalic or hexahydrophthalic anhydride.

Possibly the component B2) is used. Suitable are e.g. glycerol monoallyl, Trimethylolpropane monoallyl ether, 1,4-butenediol, dimethylolpropionic monoallyl ether or addition products of allyl glycidyl ether or glycidyl methacrylate to a carboxyl-containing polyester and mixtures of these connections.

When Component B3) are suitable (cyclo) alkanediols (i.e., divalent Alcohols with (cyclo) aliphatically bonded hydroxyl groups) of Molecular weight range 62 g / mol to 286 g / mol, e.g. ethanediol, 1,2- and 1,3-propanediol, 1,2-, 1,3- and 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, Cyclohexane-1,4-dimethanol, 1,2- and 1,4-cyclohexanediol, 2-ethyl-2-butylpropanediol, Ether oxygen-containing diols, e.g. Diethylene glycol, triethylene glycol, Tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene, Polypropylene or polybutylene glycols having a maximum number average Molecular weight of 2000 g / mol, preferably 1000 g / mol and especially preferably from 500 g / mol. Reaction products of the aforementioned Diols with ε-caprolactone can also be used as diols. As trihydric and higher alcohols are B. glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol and sorbitol, and mixtures of these compounds. Prefers are hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol and trimethylolpropane.

Possibly can also monoalcohols B4) such as e.g. Ethanol, 1- and 2-propanol, 1- and 2-butanol, 1-hexanol, 2-ethylhexanol, cyclohexanol and benzyl alcohol and mixtures these compounds are used. Preference is given to 2-ethylhexanol.

Also can optionally as component B5) hydroxycarboxylic acids of 2-10 carbon atoms, lactones such acids, Aminoalkaline the molecular weight range of 61 to 300 and / or aminocarboxylic the molecular weight range 75 to 400, e.g. Hydroxypivalic acid, dimethylolpropionic, dimethylolbutyric, lactic, malic, tartaric, ε-caprolactone, Aminoethanol, aminopropanol, diethanolamine, aminoacetic acid or aminohexanoic as well as mixtures of these compounds. Prefers is ε-caprolactone.

When Component B6) become unsaturated carboxylic acids used, such as Tetrahydrophthalic acid, tetrahydrophthalic anhydride, maleic anhydride, fumaric acid, crotonic, unsaturated Fatty acids, like e.g. Soybean oil fatty acid, tall oil fatty acid as well Mixtures of these and other unsaturated mono- or dicarboxylic acids and Mixtures of these compounds. Preference is given to maleic anhydride.

The Preparation of the polyester B) may optionally with the aid from usual Esterification catalysts, preferably according to the principle of melting or azeotropic condensation at temperatures of 140 to 240 ° C with elimination of water respectively.

in welcher
R¹ ein aliphatischer, araliphatischer oder aromatischer Rest mit 1 bis 18, bevorzugt 2 bis 10, besonders bevorzugt 4 bis 6 Kohlenstoffatomen ist,
R² H oder CH₃, bevorzugt CH₃ ist,
R³/R⁴ gleiche oder unterschiedliche aliphatische Reste mit 1 bis 7, bevorzugt 2 bis 5 Kohlenstoffatomen sind und
n 1 bis 4, bevorzugt 2 ist,
sind beispielsweise die Umsetzungsprodukte von Glycidylestern aliphatischer Carbonsäuren (α) mit aliphatischen, araliphatischen oder aromatischen Carbonsäuren (β).Suitable compounds C) of the general formula (I)

in which
R ^{1 is} an aliphatic, araliphatic or aromatic radical having 1 to 18, preferably 2 to 10, particularly preferably 4 to 6 carbon atoms,
R ^{2 is} H or CH ₃ , preferably CH ₃ ,
R ³ / R ^{4 are} identical or different aliphatic radicals having 1 to 7, preferably 2 to 5 carbon atoms and
n is 1 to 4, preferably 2,
are, for example, the reaction products of glycidyl esters of aliphatic carboxylic acids (α) with aliphatic, araliphatic or aromatic carboxylic acids (β).

Preferred compounds of component (α) are glycidyl esters of Versatic acid, which are available for example as Cardura E10P from Resolution ^® BV, Netherlands.

suitable Compounds of component (β) are saturated aliphatic monocarboxylic acids such as acetic, propionic, butyric, pentane, hexane, heptane, octane, 2-ethylhexane, nonane, decane, lauric, myristic, palmitic, margarine, Stearic, Arachin, behenic, lignoceric or unsaturated monocarboxylic acids such as oil, linoleic, Linolenic, ricinoleic acid or aromatic monocarboxylic acids such as benzoic, hexahydrobenzoic or tert-butylbenzoic acid, aliphatic Di- or polycarboxylic acids such as succinic, glutaric, adipic, pimelic, cork, azelaic, sebacin, Nonandicarboxylic, decandicarboxylic, dimer fatty acids obtained by dimerization unsaturated Monocarboxylic acids available are aromatic di- or polycarboxylic acids such as terephthalic, Isophthalic, o-phthalic, pyrometllithetetrahydrophthalic, hexahydrophthalic or trimellitic acid. Of course can also mixtures of the compounds mentioned as component (β) used become.

Prefers is the use of glycidyl esters of Versatic acid as (α) in combination with dicarboxylic acids such as succinic, adipic, terephthalic or isophthalic as Component (β). As component (β) adipic acid particularly preferred. Very particularly preferred is the combination of glycidyl esters of Versatic acid (α) with adipic acid (Β)

The Preparation of the compounds C) from the components (α) and (β) usually separate and is the polyester B) before or during the free-radical polymerization of the unsaturated monomers A1) to A4) added.

The Temperature in the preparation of compound C) is included 50 to 200 ° C, preferably at 90 to 140 ° C. Particularly preferably, the addition of compound C) takes place before radical polymerization to the submitted polyester B). Furthermore is the addition of the entire amount of the polyester B) with the compound C) or even partial amounts of the components separately or as a mixture while the copolymerization A) possible.

The Amount at the compound C) is 5 to 60 wt .-%, preferably 7 to 35 wt .-% and particularly preferably 10 to 30 wt .-%, based on the amount of Copoylmerisats (P). The amount of polyester B) is chosen so that the weight proportions of components A1) to A4) to B) 25: 75 to 90: 10, preferably 35 : 65 to 85: 15, and more preferably 50:50 to 80:20.

In general, the process for producing the polyester-polyacrylate graft polymer dispersions according to the invention is carried out by the processes known to the person skilled in the art. Typically, the compound C) and the polyester B) are initially charged in a reaction vessel and the unsaturated monomers A1) to A4) are metered in and polymerized using a free-radical initiator. In addition, it is also possible to provide only the polyester B) and to add the compound (s) C during the polymerization; In the case of particularly powerful stirring units, the addition of the compound C) can also take place only after the polymerization of the monomers A1) to A4). In addition, it is also possible to submit only parts of component B) and compound C) and to add the remainder during the polymerization.

The Copolymerization is generally preferred at 40 to 200 ° C at 60 to 180 ° C, particularly preferably carried out at 80 to 160 ° C.

Possibly can additional organic solvents be used in a subordinate amount, in particular, if you want to dilute serve the initiators. Suitable auxiliary solvents are any in lacquer technology known solvents, such as. Alcohols, ethers, alcohols containing ether groups, esters, ketones, N-methylpyrrolidone or nonpolar hydrocarbons or mixtures this solvent. The solvents are used in such quantities that their content in the finished Dispersion 0 to 5 wt .-%, preferably 1 to 3 wt .-% is. If may be required the solvents used be partially or completely removed by distillation again.

When Initiators for the polymerization reaction are suitable organic peroxides such as Di-tert-butyl peroxide, Dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, tert-butyl peroxybenzoate, Dibenzoyl peroxide, tert. Butyl perisobutyrate or tert-butyl peroxy-2-ethylhexanoate and azo compounds such as azobisisobutyronitrile (AIBN). The used Initiator quantities hang of the desired Molecular weight off. For reasons Process reliability and easier handling can be peroxide initiators also as a solution in suitable organic solvents of the type mentioned above.

The Preparation of the copolymer P) is preferably carried out in two steps (i) and (ii). In the first step (i) becomes a hydroxy-functional Monomer mixture (A ') with an OH number of 12 to 350 mg KOH / g solids, preferably 20 to 200 mg KOH / g solid and an acid number of 0 to 50 mg KOH / g Solid, preferably 0 to 30 mg KOH / g solid to those already Compounds C) and B) are given. It will be 50 to 90 Wt .-%, preferably 60 to 80 wt .-% component A1), 2 to 50 wt .-%, preferably 5 to 35% by weight of component A2), 0 to 7% by weight, preferably 0 to 5 wt .-% of component A3) and 0 to 50 wt .-%, preferably 3 to 30 Wt .-% component A4) mixed together.

In a subsequent Step (ii) becomes the reaction mixture obtained from step (i) a further monomer mixture (A '') of monomers of Components A1) to A4) was added, wherein said monomer mixture is a OH number from 10 to 350 mg KOH / g solids, preferably 18 to 200 mg KOH / g solid and an acid number from 50 to 300 mg KOH / g solids, preferably 70 to 200 mg KOH / g Solid has. The monomer mixture (A '') from step (ii) while 45 to 85 wt .-%, preferably 55 to 75 wt .-% component A1), From 1 to 50% by weight, preferably from 5 to 35% by weight, of component A2) from 3 to 30 Wt .-%, preferably 8 to 22 wt .-% of component A3) and 0 to 50 wt .-%, preferably from 3 to 30% by weight of component A4).

The % Data of monomer composition (A ') and (A' ') add up to 100 wt .-%.

The Monomer quantities of the two Polymerisatherstellungen are so to choose, that the mass ratio the Momomermischung (A ') to monomer mixture (A ") 10: 1 to 1: 2, preferably 6: 1 to 2: 1.

Instead of a multi-stage polymerization process, it is also possible the Process continuously (gradient polymerization), i. a monomer mixture with a time-varying composition is added, wherein preferably the hydrophilic monomer proportions according to the components A3) and optionally A4) are higher towards the end of the feed than at the beginning.

The copolymers (P) have number-average molecular weights M _{n of} from 500 to 30,000 g / mol, preferably from 1,000 to 15,000 g / mol, more preferably from 1,500 to 10,000 g / mol.

In front, while or after the dispersion of the hydroxy-functional copolymers (P) in water, the existing acid groups are at least proportionally converted into its salt form by adding suitable neutralizing agents. Prefers are potentially ionic groups of the copolymer (P) before the Dispersion neutralized. Suitable as neutralizing agent are organic amines or water-soluble inorganic bases, such as. soluble Metal hydroxides, carbonates or bicarbonates.

Examples of suitable amines are N-methylmorpholine, triethylamine, ethyldiisopropylamine, N, N-dimethylethanolamine, N, N-dimethylisopropanolamine, N-methyldiethanolamine, diethylethanolamine, triethanola min, butanolamine, morpholine, 2-aminomethyl-2-methyl-propanol or isophoronediamine. In mixtures, it is also possible to use ammonia proportionally. Preferred are triethanolamine, N, N-dimethylethanolamine and ethyldiisopropylamine.

The Neutralizing agents are added in amounts such that in Sum of a theoretical degree of neutralization [of the acid groups] from 40 to 150%, preferably 60 to 120%. The degree of neutralization is understood itself as a molar ratio of added basic groups of the neutralization component to acid functions of the copolymer (P).

Of the pH of the polyester-polyacrylate-Pfopfpolymerisat dispersion according to the invention is 6 to 10, preferably 6.5 to 9.

The aqueous, Polyester-polyacrylate-Pfopfpolymerisat dispersions have a Solids content from 25 to 70% by weight, preferably 35 to 60% by weight, more preferably from 40 to 55% by weight.

The Polyester-polyacrylate-Pfopfpolymerisat dispersions of the invention can to aqueous coating agents are processed. By combining with crosslinkers, you can depending on the reactivity or optionally blocking the crosslinkers, both one-component paints as well as two-component paints are produced.

Also The present invention relates to aqueous coating compositions containing the aqueous according to the invention Polyester-polyacrylate dispersions Pfopfpolymerisat.

Under One-component paints in the context of the present invention are coating agents to understand where binder component and crosslinker component can be stored together without that a crosslinking reaction in noticeable or for later application malicious Extent takes place. The crosslinking reaction takes place only after application after activation the crosslinker instead. This activation may e.g. by increasing the temperature be effected.

Under Two-component paints according to the present invention understands coating agent, in which binder component and crosslinker component due their high reactivity stored in separate containers Need to become. The two components are mixed just before application and then generally respond without additional activation. For acceleration the crosslinking reaction can but also used catalysts or higher temperatures become. The use of the polyester-polyacrylate-Pfopfpolymerisat dispersions of the invention in two-component paints is preferred.

suitable OH-group-reactive crosslinkers are, for example, polyisocyanate crosslinkers, Amide and amine formaldehyde resins, phenolic resins, aldehyde and ketone resins, such as. Phenol-formaldehyde resins, resols, furan resins, urea resins, Carbamidsäureesterharze, Triazine resins, melamine resins, benzoguanamine resins, cyanamide resins, aniline resins, as described in "Lackkunstharze", H. Wagner, H.F. Sarx, Carl Hanser Verlag Munich, 1971, are described.

Prefers are used as crosslinking agents polyisocyanates, which are typically 2 or more NCO groups per molecule and, for example, isophorone diisocyanate, hexamethylene diisocyanate, 1,4-diisocyanatocyclohexane, bis (4-isocyanatocyclohexane) -methane, 1,3-diisocyanatobenzene, triisocyanatononane or the isomeric 2,4- and 2,6-TDI are based and further urethane, isocyanurate and / or Biuret groups may have. If necessary, you can the polyisocyanates also be blocked.

Especially the use is preferably of low viscosity, optionally hydrophilized Polyisocyanates of the aforementioned type based on aliphatic or cycloaliphatic isocyanates.

The polyisocyanates used as crosslinkers generally have at 23 ° C a viscosity from 10 to 5 000 mPas and can also, if viscosity adjustment required used in admixture with small amounts of inert solvents.

The Copolymers (P) are generally sufficiently hydrophilic, so that hydrophobic crosslinker resins dispersed without additional emulsifiers can be. However, a use of external emulsifiers is not excluded.

Water soluble or dispersible polyisocyanates are e.g. by modification with carboxylate, Sulfonate and / or polyethylene oxide groups and / or polyethylene oxide / polypropylene oxide groups available. Hydrophilization of the polyisocyanates is e.g. through implementation with deficient ones Amounts of monohydric, hydrophilic polyether alcohols possible. The Preparation of such hydrophilicized polyisocyanates is, for example in EP-A 0 540 985 (page 3, Z 55 to page 4 Z.5) described.

Also suitable are the polyisocyanates containing allophanate groups described in EP-A 959 087 (pages 3 to 39 to 51), which are prepared by reacting low-monomer polyisocyanates with polyethylene oxide polyether alcohols under allophanatization conditions. The water-dispersible polyisocyanate mixtures based on triisocyanatononane described in DE-A 100 078 21 (page 2 Z. 66 to page 3 Z.5) are also suitable, as well as with ionic groups (sulfonate, phosphonate) hydrophilicized polyisocyanates, such as eg in the DE 100 24 624 (P. 3 Z. 13 to 33) are described.

in principle is natural also the use of mixtures of different crosslinker resins possible.

In front, while or after the preparation of the aqueous, polyester-polyacrylate-Pfopfpolymerisat dispersion according to the invention can the usual Additives and additives are added to the paint technology, such as e.g. defoamers, Thickeners, pigments, dispersants, catalysts, skin preventatives, Anti-settling agents or emulsifiers.

These Auxiliaries and additives can also the coating composition comprising the aqueous, hydroxy-functional polyester-polyacrylate graft polymer dispersions, be added.

The aqueous Coating composition comprising the aqueous, hydroxy-functional polyester-polyacrylate graft polymer dispersions, are suitable for all applications in which aqueous Painting and coating systems with high demands on the resistance the films are used, e.g. for the coating of mineral Building material surfaces, paint and sealing of wood and wooden materials, coating metallic surfaces (Metal coating), coating and painting asphalt or bituminous coverings, Painting and sealing of various plastic surfaces (plastic coating) as well as high gloss paints.

The aqueous Coating composition comprising the aqueous, Polyester-polyacrylate dispersions Pfopfpolymerisat, are used to make primers, fillers, pigmented or transparent Topcoats, clearcoats and high-gloss lacquers and single-coat lacquers, the in single and serial application, e.g. in the field of industrial painting, Automotive first and Repair varnish application can be used. Prefers is the use as a multilayer construction, with the top layer a topcoat or clearcoat is by curing the aqueous, Polyester-polyacrylate-Pfopfpolymerisat dispersion is produced.

The Production of the coatings can be done by the different spraying methods such as air pressure, airless or electrostatic spray using on or off optionally carried out two-component spray systems. The paints and coating compositions containing the aqueous, However, hydroxy-functional polyester-polyacrylate grafted polymer dispersions may also be used after other methods, for example by swiping, rolling or Doctor blades are applied.

So far not indicated otherwise, all percentages are based on Weight.

-Plate viscometer cone Pysica Viscolab ^® LC3 ISO from Physica, Stuttgart, Germany in accordance with DIN Viscosity measurements were made with a carried out at a shear rate of 40 s ^-1 53,019th

The Determination of the average particle size was carried out by means of laser correlation spectroscopy (HPPS, Malvern Instruments, Herrenberg, DE).

The Measurement of the gloss of the paint films is carried out according to DIN 67530

The indicated OH numbers were calculated from the OH-bearing components used.
Acid numbers: Determination method, DIN ISO 3682
Cardura ^® E10P: glycidyl ester of versatic Resolution BV, NL.
Peroxan ^® DB: Di-tert-butyl peroxide, Pergan GmbH, Bocholt, Germany.
Bayhydur® ^® VP LS 2319: Hydrophilized polyisocyanate from Bayer MaterialScience AG Leverkusen, Germany..
Proglyde ^® DMM: dipropylene, solvents Dow Chemical, Ahlen, Germany.
Baysilone® ^® VP AI 3466: leveling agents, Borchers GmbH, Langenfeld, Germany.
Baysilone® ^® VP AI 3468: leveling agents, Borchers GmbH, Langenfeld, Germany.
Borchigel ^® PW 25: thickeners, Borchers GmbH, Langenfeld, Germany.

Example 1: Reactive Diluent

In a 5 l reaction vessel with stirrer, cooling and heating device are weighed at 20 ° C 3172 g of Cardura ^® E10P and 927 g of adipic acid. While stirring, it is heated to 140.degree. From about 140 ° C, an exothermic reaction takes place. It is stirred for a further 4 hours at 140 ° C. A bright yellow resin having a viscosity of 2,900 mPas at 23 ° C. is obtained.

Example 2: polyester precursor

1659 g of trimethylolpropane, 5146 g of neopentyl glycol are weighed into a 20 l reaction vessel with stirrer, cooling and heating apparatus and water separator at 20 ° C. and melted at 100 ° C. 122 g of maleic anhydride, 2059 g of isophthalic acid and 5666 g of phthalic anhydride are then added, with stirring, and the mixture is heated to 150 ° C. within one hour while passing a stream of nitrogen through it. Afterwards, the temperature is set to 200 ° C. within 6 h and condensed in the nitrogen stream until the acid number drops below 8 mg KOH / g substance.
Acid number: 5.9 mgKOH / g
OH number: 122 mgKOH / g

Example 3:

In a 4 l reaction vessel with stirring, cooling and heating 750 g of polyester precursor according to Example 2 and 123.4 g of reactive diluent according to Example 1 and 48.7 g of butyldiglycol are initially charged and heated to 140 ° C. At this temperature, a solution of 11.3 g Peroxan ^® DB is added dropwise in 22.5 g of butyl diglycol the course of 125 minutes. Five minutes after starting the metering of the initiator solution, a monomer mixture of 185 g of methyl methacrylate, 150 g of hydroxyethyl methacrylate, 50 g of butyl acrylate, 50 g of isobutyl methacrylate and 35 g of styrene is metered in within 2 hours. Immediately thereafter, a mixture of 92.5 g of methyl methacrylate, 75 g of hydroxyethyl methacrylate, 25 g of butyl acrylate, 25 g of isobutyl methacrylate, 17.5 g of styrene and 45 g of acrylic acid is metered in within 60 minutes. parallel to this, a solution of 11.3 g of di-tert-butyl peroxide in 23.5 g of butyl diglycol is added uniformly over 2 hours. The mixture is then stirred for 1 h at 140 ° C, cooled to 100 ° C and added 47 g of dimethyl ethanolamine. After 20 minutes of homogenization is dispersed within 10 minutes at 90 ° C with 1650 g of water. At the reached mixing temperature of 78 ° C is further homogenized for 1.5 h, before the dispersion is then filtered and cooled to room temperature. OH content (solids) 4.22% (theoretically calculated) Acid number (solid) 24.5 mg KOH / g Solids content 48% viscosity 1280 mPas / 23 ° C pH value (10% in water) 7.6 Degree of neutralization 75% Mean particle size 140 nm co-solvent content 2.9 wt .-% based on dispersion

Example 4:

In a 4 l reaction vessel with stirring, cooling and heating 750 g of polyester precursor according to Example 2 and 210.2 g of reactive diluent according to Example 1 are introduced and heated to 140 ° C. At this temperature, a solution of 11.3 g Peroxan ^® DB is added dropwise in 22.5 g of butyl diglycol the course of 125 minutes. Five minutes after starting the metering of the initiator solution, a monomer mixture of 185 g of methyl methacrylate, 150 g of hydroxyethyl methacrylate, 50 g of butyl acrylate, 50 g Isobutylmethacrylat and 35 g of styrene added. Immediately thereafter, a mixture of 92.5 g of methyl methacrylate, 75 g of hydroxyethyl methacrylate, 25 g of butyl acrylate, 25 g of isobutyl methacrylate, 17.5 g of styrene and 45 g of acrylic acid is metered in within 60 minutes; parallel to this, a solution of 11.3 g of di-tert-butyl peroxide in 23.5 g of butyl diglycol is added uniformly over 2 hours. The mixture is then stirred for 1 hour at 140 ° C, cooled to 100 ° C and added 45 g of dimethyl ethanolamine. After 20 minutes of homogenization is dispersed within 10 minutes at 90 ° C with 1725 g of water. At the reached mixing temperature of 78 ° C is further homogenized for 1.5 h, before the dispersion is then filtered and cooled to room temperature. OH content (solids) 4.54% (theoretically calculated) Acid number (solid) 21.6 mg KOH / g Solids content 44% viscosity 1310 mPas / 23 ° C pH value (10% in water) 7.6 Degree of neutralization 75% Mean particle size 137 nm co-solvent content 1.45 wt .-% based on dispersion

Example 5

In a 4 l reaction vessel with stirrer, cooling and heating device, 750 g of polyester precursor according to Example 2 and 314.7 g of reactive diluent according to Example 1 are initially charged and heated to 140.degree. At this temperature, a solution of 11.3 g of Peroxan ^® DB in 22.5 g of butyl diglycol is added dropwise within 125 min. Five minutes after starting the metering of the initiator solution, a monomer mixture of 185 g of methyl methacrylate, 150 g of hydroxyethyl methacrylate, 50 g of butyl acrylate, 50 g of isobutyl methacrylate and 35 g of styrene is metered in within 2 hours. Immediately thereafter, a mixture of 92.5 g of methyl methacrylate, 75 g of hydroxyethyl methacrylate, 25 g of butyl acrylate, 25 g of isobutyl methacrylate, 17.5 g of styrene and 45 g of acrylic acid is metered in within 60 minutes; parallel to this, a solution of 11.3 g of di-tert-butyl peroxide in 23.5 g of butyl diglycol is added uniformly over 2 hours. The mixture is then stirred for 1 hour at 140 ° C, cooled to 100 ° C and added 45 g of dimethyl ethanolamine. After 20 minutes of homogenization is dispersed within 10 minutes at 90 ° C with 1725 g of water. At the reached mixing temperature of 78 ° C is further homogenized for 1.5 h, before the dispersion is then filtered and cooled to room temperature. OH content (solids) 4.94% (calculated theoretically) Acid number (solid) 25.9 mg KOH / g Solids content 44% viscosity 970 mPas / 23 ° C pH value (10% in water) 7.6 Degree of neutralization 75% Mean particle size 156 nm Colösergehlat 1.45 wt .-% based on dispersion

Comparative Example 6

In a 4 l reaction vessel with stirring, cooling and heating device, 750 g of polyester precursor according to Example 2 and 223.7 g of butyldiglycol are initially charged and heated to 140.degree. At this temperature, a solution of 11.3 g Peroxan ^® DB in 22.5 g of butyl diglycol is within 125 min added dropwise.. Five minutes after starting the metering of the initiator solution, a monomer mixture of 185 g of methyl methacrylate, 150 g of hydroxyethyl methacrylate, 50 g of butyl acrylate, 50 g of isobutyl methacrylate and 35 g of styrene is metered in within 2 hours. Immediately thereafter, a mixture of 92.5 g of methyl methacrylate, 75 g of hydroxyethyl methacrylate, 25 g of butyl acrylate, 25 g of isobutyl methacrylate, 17.5 g of styrene and 45 g of acrylic acid is metered in within 60 minutes; parallel to this, a solution of 11.3 g of di-tert-butyl peroxide in 23.5 g of butyl diglycol is added uniformly over 2 hours. The mixture is then stirred for 1 hour at 140 ° C, cooled to 100 ° C and added 45 g of dimethyl ethanolamine. After 20 minutes of homogenization is dispersed within 10 minutes at 90 ° C with 1725 g of water. At the reached mixing temperature of 78 ° C is further homogenized for 1.5 h, before the dispersion is then filtered and cooled to room temperature. OH content (solids) 3.75% (calculated theoretically) Acid number (solid) 25.7 mg KOH / g Solids content 45.3% viscosity 2300 mPas / 23 ° C pH value (10% in water) 7.6 Degree of neutralization 75% Mean particle size 132 nm Colösergehlat: 6.8 wt .-% based on dispersion

application Technology dates

• 0 = Keine Veränderung des Lackfilms, 5 = Lackfilm völlig zerstört
• ^*Härterlösung: 75 Gew.-Tl. Bayhydur^® VP LS 2319 gelöst in 25 Gew.-Tl. Proglyde^® DMM)
• ^** 2-Methoxypropylacetat

The binder mentioned in the examples are formulated with additives, then mixed with a 75% solution of the Polyisocyants Bayhydur LS 2319 ^{® ®} Proglyde DMM in the Fa. Dow Chemicals, applied to the clear coat and baked 30 minutes at 60 ° C. After storage of the paint films for 2 days at room temperature, the paint films were evaluated.

• 0 = no change in the paint film, 5 = paint film completely destroyed
• ^* Hardener solution: 75 parts by weight Bayhydur® ^® VP LS 2319 dissolved in 25 parts by weight Proglyde ^® DMM)
• ^** 2-methoxypropyl acetate

Claims (11)

A process for preparing aqueous, hydroxy-functional polyester-polyacrylate graft polymer dispersions having a cosolvent content of 0 to 5 wt .-%, based on the dispersion, characterized in that in a first step, a copolymer (P) by polymerization A) a Mixture for free-radical copolymerization of vinyl monomers A1) to A4) in the presence of B) one or more polyester polyol (s) having a hydroxyl number of 10 to 500 mg KOH / g subsidence and an acid number of> 0.5 to ≤30 mg KOH / g substance and a double bond content (calculated as C = C, molecular weight 24) of 0.1 to 5%, and C) one or more compound (s) of the general formula (I),

wherein R ^{1 is} an aliphatic, araliphatic or aromatic radical of 1 to 18 carbon atoms, R ^{2 is} H or CH ₃ , R ³ / R ^{4 are the} same or different aliphatic radicals of 1 to 7 carbon atoms and n is 1 to 4 and the copolymer (P) thus obtained is subsequently dispersed in water in a second step before or after addition of a neutralizing agent. Method according to claim 1, characterized in that in a reaction vessel the compound C) and the polyester B) is introduced and the unsaturated Monomers A1) to A4) are metered in and using a free-radical initiator be polymerized. Method according to claim 2, characterized in that a two-stage addition and polymerization the unsaturated one Monomers A1) to A4), wherein in the first stage (i) a hydroxy-functional monomer mixture (A ') with an OH number of 12 to 350 mg KOH / g solid and an acid number from 0 to 50 mg KOH / g solids to the already presented compounds C) and B) is added and then in a second stage (ii) to the reaction mixture obtained from step (i) is a added more monomer mixture (A ''), wherein this monomer mixture has an OH number of 10 to 350 mg KOH / g solids and an acid number from 50 to 300 mg KOH / g of solid. Method according to claim 1, characterized in that compounds C) of the general Formula (I) Reaction products of glycidyl esters of aliphatic carboxylic acids (α) with aliphatic, araliphatic or aromatic carboxylic acids (β). Method according to claim 4, characterized in that compounds C) of the general Formula (I) Reaction products of glycidyl esters of Versatic acid as (α) in combination with adipic acid as component (β) are. Polyester-polyacrylate dispersions Pfopfpolymerisat available by methods according to claim 1. Polyester-polyacrylate dispersions Pfopfpolymerisat according to claim 6, characterized in that the content of Colöser 1 to 3 wt .-%, based on the dispersion. aqueous Coating compositions containing polyester-polyacrylate-Pfopfpolymerisat dispersions according to claim 6th Use of the polyester-polyacrylate graft polymer dispersions according to claim 6 for the production of two-component coatings. Use of the polyester-polyacrylate graft polymer dispersions according to claim 6 for the production of topcoats and clearcoats. Multilayer construction with a topcoat or clearcoat as the top coat, which by curing the polyester-polyacrylate-Pfopfpolymerisat dispersions according to claim 6 is obtained.