EP1948741A2

EP1948741A2 - Aqueous powder dispersion, which can be cured by radical polymerization, method for the production thereof and their use

Info

Publication number: EP1948741A2
Application number: EP06828966A
Authority: EP
Inventors: Hubert Baumgart; Bertold Austrup; Bostjan Muhic
Original assignee: BASF Coatings GmbH
Current assignee: BASF Coatings GmbH
Priority date: 2005-11-10
Filing date: 2006-11-09
Publication date: 2008-07-30
Also published as: DE102005053663A1; CN101305059A; JP2009515018A; WO2007054289A2; WO2007054289A3; US20090298997A1; KR20080080523A; KR101003917B1

Abstract

The invention relates to radiation polymerization-curable, aqueous, structurally viscose, volatile organic compounds of whole or, in essence, free powder dispersions containing, as a dispersed phase, solid and/or highly viscous particles (A), which are dimensionally stable under conditions of storage and use and which have a mean particle size z-Mean of 80 to 750 nm measured with photon correlation spectroscopy. Particles (A) contain at least one radically cross-linkable binder (A1) with a glass transition temperature ranging from -70 to +50°C, with a content of olefinically unsaturated double bonds of 2 to 10 equ./kg and with a content of acid groups of 0.05 to 15 equ./kg in a quantity of 50 to 100 % by weight with regard to (A). The invention also relates to methods for producing these dispersions and to the use thereof.

Description

Radical polymerization curable, aqueous powder dispersions, process for their preparation and their use

Field of the invention

The present invention relates to novel, by radical polymerization curable, aqueous powder dispersions. In addition, the present invention relates to a novel process for the preparation of free-radically polymerizable, aqueous powder dispersions. Furthermore, the present invention relates to the use of novel, curable by radical polymerization, aqueous powder dispersions and prepared by the new method, curable by free radical polymerization, aqueous powder dispersions as coating materials, adhesives and sealants for the production of coatings, adhesive layers and seals.

State of the art

Aqueous powder dispersions, in particular aqueous powder coating dispersions, are known to experts as "powder slurries" or "slurries" for short.

For the sake of brevity, the term "slurries" here and below refers to powder slurries curable by free-radical polymerization.

It is known that the free radical polymerization is carried out with compounds containing olefinically unsaturated double bonds. The radical polymerization can be initiated and maintained thermally or with actinic radiation.

Here and below actinic radiation electromagnetic radiation, such as near infrared (NIR), visible light, UV radiation, X-rays or gamma rays, in particular UV radiation, or corpuscular radiation, such as electron radiation, proton radiation, beta radiation, alpha radiation or neutron radiation, in particular electron radiation , Understood.

US Pat. No. 6,432,490 B1 or the corresponding international patent application WO 02/064267 A2 discloses slurries containing ionically stabilized urethane acrylates having a content of unsaturated double bonds or a double bond equivalent weight of 0.1 to 10 equ./kg. However, details of the ionic stabilization are lacking and only a conventional clearcoat based on organic solvents and a urethane acrylate free of acid groups is apparent from the examples.

The known slurries can be cured after their application with near infrared and provide hard, solvent-resistant and yellowing-free coatings, especially clearcoats.

Structural viscous slurries are known from the German patent application DE 199 08 013 A1 whose solid, spherical particles have an average particle size of 0.8 to 20 μm measured using the laser diffraction method and a maximum particle size of 30 μm.

The curable with actinic radiation components of the known slurries have a content of ion-forming groups, in particular carboxyl groups, from 0.05 to 1 equ./kg and a content of neutralizing agents from 0.05 to 1 equ./kg.

The known slurries have at a shear rate of 1000 s ^"1 a viscosity of 50 to 1,000 mPas, at a shear rate of 10 s ^{" 1} such from 150 to 8,000 mPas and 1 s ^{' 1} such from 180 to 12,000.

From the examples, however, only a urethane acrylate having a double bond equivalent weight of 3 equ./kg emerges, but which contains no acid groups. It is contained in the particles of the relevant slurry in an amount of 41, 53 wt .-%, based on the solids.

The known slurries can be cured after their application with UV radiation and provide coatings, especially clearcoats, which have an excellent appearance (Appearance), a high chemical resistance, a high hardness and a smooth surface. They also have no cookers in layer thicknesses of 40 to 50 μm and are free of cracking (mud cracking).

However, the performance characteristics of the known slurries must be constantly further developed to meet the increasing demands of the market.

In particular, the coatings produced from the known slurries, in particular clearcoats, with regard to chemical resistance, Rockfall resistance, scratch resistance and condensation resistance are further developed.

task

It is an object of the present invention to find novel aqueous powder dispersions which can be hardened by free-radical polymerization (referred to collectively below as "new slurries") which can be prepared in a simple manner and with very good reproducibility.

The new slurries should be particularly stable in storage, excluding actinic radiation, and should not tend to settle and / or agglomerate. If, after a relatively long time, there is still a slight sedimentation and / or agglomeration of particles, the sedimented particles should disperse again quickly by brief stirring and the agglomerated particles should be rapidly comminuted again.

The new slurries are said to provide coatings, in particular clearcoats, which have excellent appearance properties, in particular high gloss. It should be particularly resistant to chemicals, condensation and mechanical impact, especially by stone chipping. In addition, they should be highly scratch-resistant. In addition, they should effectively level out any unevenness in the surface, which can be felt up to the top coat of a multicoat paint system, and thus have a particularly smooth and trouble-free surface. Above all, they should still be free of digesters and mud cracking in particularly high layer thicknesses of more than 80 μm.

solution

Accordingly, the novel, free-radically polymerizable, aqueous, pseudoplastic, completely or substantially free of volatile organic compounds powder dispersions were found containing as disperse phase solid and / or highly viscous storage and application conditions dimensionally stable particles (A) with one with the photon correlation spectroscopy measured average particle size z

Mean of 80 to 750 nm, wherein the particles (A) at least one free-radically crosslinkable binder (A1) having a glass transition temperature of -70 to + 50 ° C, a content of olefinically unsaturated double bonds of 2 to 10 equ./kg and a content at Acid groups of 0.05 to 15 equ./kg in an amount of, based on (A), 50 to 100 wt .-%.

In the following, the novel, curable by radical polymerization, aqueous, pseudoplastic, volatile organic compounds free or substantially free powder dispersions are referred to as "slurries invention".

In addition, the novel process for producing the slurries according to the invention was found, in which the particles (A) are dispersed in an aqueous medium (B) and which is referred to below as the "process according to the invention".

In addition, the novel use of the slurries according to the invention and of the slurries prepared by the process according to the invention has been found as coating materials, adhesives and sealants for the production of coatings, adhesive layers and seals, which is referred to below as "use according to the invention".

Other subjects of the invention will become apparent from the description.

advantages

In view of the prior art, it was surprising and unforeseeable for the skilled person that the object on which the present invention was based could be achieved with the aid of the slurries according to the invention, the process according to the invention and the use according to the invention.

In particular, it was surprising that the slurries according to the invention could be prepared in a simple manner and with very good reproducibility.

The slurries according to the invention were particularly stable in storage, excluding actinic radiation, and did not tend to settle and / or agglomerate. If, after some time, the sedimentation and / or agglomeration of particles (A) were still slight, the sedimented particles (A) could be quickly dispersed again by brief stirring and the agglomerated particles (A) rapidly comminuted again.

The slurries according to the invention gave coatings according to the invention, in particular clearcoats according to the invention, which had outstanding optical properties (appearance), in particular high gloss. They were particularly stable against chemicals, condensation and mechanical impact, especially by stone chipping ,. In addition, they were highly scratch resistant. In addition, they leveled out unevenness in the substrate, which otherwise permeated the top coat of a multicoat paint system, and therefore had a particularly smooth and trouble-free surface. Above all, however, they were still free from digesters and mud cracking even in particularly high layer thicknesses of more than 80 μm.

Detailed description of the invention

The slurry according to the invention is completely or substantially free of organic solvents.

"Substantially free" means that the slurry according to the invention has a solvent content <10% by weight, preferably in each case <5% by weight and in particular <2% by weight).

"Completely free from" means that the solvent content is below the usual and known detection limits for organic solvents.

The slurry according to the invention is structurally viscous.

The viscosity behavior, referred to as "pseudoplastic," describes a state which, on the one hand, takes account of the requirements of storage and settling stability of the slurry according to the invention: in the agitated state, for example when pumping the slurry according to the invention in the ring line of a coating plant and when applied, the slurry of the invention assumes a low-viscosity state, which ensures good processability. Without shear stress, on the other hand, the viscosity increases and in this way ensures that the slurry according to the invention already present on the substrate to be coated has a reduced tendency to run off on vertical surfaces ("run formation"). In the same way, the higher viscosity in the unmoved state, such as during storage, for the most part prevents sedimentation of the solid particles (A) or ensures that the slurry of the invention which is only slightly deposited and / or agglomerated during the storage time is stirred up again. The pseudoplastic behavior is preferably adjusted by means of suitable thickeners (A2), in particular nonionic and ionic thickeners (A2), which are preferably present in the aqueous phase (B).

For the pseudoplastic behavior, preference is given to setting a viscosity range of 50 to 1,500 mPas at a shear rate of 1,000 s ^-1 and from 150 to 8,000 mPas at a shear rate of 10 s ^-1 and from 180 to 12,000 mPas at a shear rate of 1 s ^-1 ,

The slurry according to the invention contains as disperse phase solid and / or highly viscous, dimensionally stable particles (A).

"Dimensionally stable" means that under the usual and known conditions of storage and application of pseudoplastic aqueous powder dispersions, the particles (A) only slightly agglomerate, if at all, and / or disintegrate into smaller particles, but also under the influence of shear forces preserve the original form completely or substantially.

The particles (A) have an average particle size z-mean of 80 to 750 nm, preferably 80 to 600 nm and in particular 80 to 400 nm, measured by photon correlation spectroscopy.

Photon correlation spectroscopy is a common and known method for measuring dispersed particles with particle sizes <1 μm. For example, the measurement can be performed using the Malvern® Zetasizer 1000.

The particle size distribution can be adjusted in any way. Preferably, the particle size distribution results from the use of suitable wetting agents (A2).

The content of the slurry of particles (A) according to the invention can vary very widely and depends on the requirements of the individual case.

The content is preferably from 5 to 70, preferably from 10 to 60, more preferably from 15 to 50 and in particular from 15 to 40,% by weight, based on the inventive slurry.

The particles (A) contain at least one, in particular a, radically crosslinkable binder (A1) a glass transition temperature of -70 to +50 ⁰ C, preferably -60 to + 20 ⁰ C and in particular -60 to +10 ⁰ C,

a content of olefinically unsaturated double bonds of 2 to 10 equ./kg, preferably 2 to 8 equ./kg, preferably 2.1 to 6 equ./kg, more preferably 2.2 to 6 equ./kg, very particularly preferably 2.3 to 5 equ./kg and in particular 2.5 to 5 equ./kg of the binder (A1) and

a content of acid groups of 0.05 to 15 equ./kg, preferably 0.08 to 10 equ./kg, preferably 0.1 to 8 equ./kg, more preferably 0.15 to 5 equ./kg, most preferably 0.18 to 3 equ./kg and in particular 0.2 to 2 equ./kg of the binder (A1).

The content of acid groups is preferably determined by the acid number according to DIN EN ISO 3682.

The particles (A) contain the binders (A1) in an amount of 50 to 100 wt.%, Preferably 55 to 100 wt.%, Preferably 60 to 99 wt.%, Particularly preferably 70 to 99 wt. and in particular 80 to 99 wt .-%, each based on (A).

Thus, the particles (A) may consist of the binder (A1). The particles (A) preferably also comprise at least one of the additives (A2) described below.

Preferably, the olefinically unsaturated double bonds of the binder (A1) lie in groups selected from the group consisting of (meth) acrylate, ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester, dicyclopentadienyl, norbornyl, isoprenyl , Isopropenyl, allyl or butenyl groups; Dicyclopentadienyl, norbomenyl, isoprenyl, isopropenyl, allyl or butenyl ether groups or dicyclopentadienyl, norbornyl, isoprenyl, isopropenyl, allyl or butenyl ester groups, preferably (meth) acrylate groups. In particular, the olefinically unsaturated double bonds are present in acrylate groups.

The binders (A1) are oligomeric or polymeric.

"Oligomer" means that the relevant binder (A1) is composed of 3 to 12 monomeric structural units. "Polymer" means that the relevant binder (A1) is composed of more than 8 monomeric structural units.

Whether a binder (A1) composed of 8 to 12 monomeric units is considered to be an oligomer or a polymer depends primarily on its number average molecular weight.

The number average molecular weight of the binder (A1) can vary very widely and depends on the requirements of the individual case, in particular the viscosity, which is advantageous for the processing and the use of the binder (A1). Thus, the viscosity of the binder (A1) is usually adjusted so that a smooth and easy filming of the particles (A) is achieved after the application of the slurry according to the invention and the drying of the resulting wet layer.

The number-average molecular weight is preferably from 1000 to 50,000 daltons, preferably from 1,500 to 40,000 daltons and in particular from 2,000 to 20,000.

The nonuniformity of the molecular weight may likewise vary widely and is preferably from 1 to 10, in particular from 1.5 to 8.

Suitable binders (A1) are all oligomers and polymers which have the property profile described above.

Preferably, the binder (A1) is selected from the group consisting of oligomeric and polymeric epoxy (meth) acrylates, urethane (meth) acrylates and carbonate (meth) acrylates. In particular, urethane (meth) acrylates are used.

The urethane (meth) acrylates (A1) can be prepared by reacting

(a1) at least one compound containing at least two isocyanate groups, selected from the group consisting of aliphatic, aromatic or cycloaliphatic di- and polyisocyanates, with

(a2) at least one compound having at least one, in particular one, isocyanate-reactive functional group, preferably selected from the group consisting of hydroxyl groups, thiol groups and primary and secondary Amino groups, in particular hydroxyl groups, and at least one, in particular one, of the groups described above which contain a free-radically polymerizable, olefinically unsaturated double bond, preferably a (meth) acrylate group, in particular an acrylate group,

(a3) at least one compound having at least one, in particular one, isocyanate-reactive functional group and at least one, in particular one, acid group, preferably selected from the group consisting of carboxylic, phosphonic, phosphinic, sulfonic, and sulfinic, preferably carboxylic acid - And sulfonic acid groups, in particular carboxylic acid groups, and

(a4) if appropriate, at least one compound having at least two, in particular two, isocyanate-reactive functional groups.

Examples of suitable compounds (a1) are customary and known di- and polyisocyanates having an isocyanate functionality of on average 2 to 6, preferably 2 to 5 and in particular 2 to 4.

"Aliphatic" means that the isocyanate group in question is linked to an aliphatic carbon atom.

"Cycloaliphatic" means that the isocyanate group in question is linked to a cycloaliphatic carbon atom.

"Aromatic" means that the isocyanate group in question is linked to an aromatic carbon atom.

Examples of suitable aliphatic diisocyanates (a1) are aliphatic diisocyanates, such as tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate,

Octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, derivatives of lysine diisocyanate,

Tetramethylxylylidenediisocyanat, trimethylhexane diisocyanate or 1, 3- or 1, 4-bis (isocyanatomethyl) cyclohexane.

Examples of suitable cycloaliphatic diisocyanates (a1) are 1, 4, 1, 3 or 1, 2-diisocyanatocyclohexane, tetramethylcyclohexane diisocyanate, bis (4'- isocyanatocyclohexyl) methane, (4'-isocyanatocyclohexyl) - (2'-isocyanatocyclohexyl) methane, 2,2-bis (isocyanatocyclohexyl) propane, 2,2- (4'-isocyanatocyclohexyl) - (2'-isocyanatocyclohexyl) propane, 1- isocyanato-3,3,5-trimethyl-5- (isocyanatomethyl) cyclohexane (isophorone diisocyanate), 2,4- or 2,6-diisocyanato-1-methylcyclohexane or diisocyanates derived from dimer fatty acids, such as those sold under the trade name DDI 1410 by the Henkel and described in the patents WO 97/49745 and WO 97/49747, such as 2-heptyl-3,4-bis (9-isocyanatononyl) -1-pentyl-cyclohexane.

Examples of suitable aromatic diisocyanates (a1) are 2,4- or 2,6-toluylene diisocyanate or mixtures thereof, m- or p-xylylene diisocyanate, 2,4'- or 4,4'-

Diisocyanatodiphenylmethane or isomer mixtures thereof, 1, 3 or 1, 4

Phenylene diisocyanate, 1-chloro-2,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate,

Diphenylene-4,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 3-methyl-diphenylmethane-4,4'-diisocyanate, 1, 4-diisocyanatobenzene or 4,4'-diisocyanato-diphenyl ether ,

Preferably, aliphatic and cycloaliphatic diisocyanates (a1), especially hexamethylene diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate and / or di (isocyanatocyclohexyl) methane used.

Examples of suitable polyisocyanates (a1) are triisocyanates such as nonane triisocyanate (NTI) and polyisocyanates (a1) based on the above-described diisocyanates and triisocyanates (a1), especially oligomers containing isocyanurate, biuret, allophanate, iminooxadiazinedione, urethane, Carbodiimide, urea, uretonimine and / or uretdione groups. Examples of suitable polyisocyanates (a1) of this type and processes for their preparation are described, for example, in patents and patent applications CA 2,163,591 A 1, US Pat. No. 4,419,513 A, US Pat. No. 4,454,317 A, EP 0 646 608 A1, US Pat. No. 4,801,675 A, EP 0 183 976 A 1, DE 40 15 155 A1, EP 0 303 150 A1, EP 0 496 208 A1, EP 0 524 500 A1, EP 0 566 037 A1, US Pat. No. 5,258,482 A, US Pat. No. 5,290,902 A, EP 0 649 806 A 1, DE 42 29 183 A 1 or EP 0 531 820 A 1 known.

Preferably, the oligomers (a1) of hexamethylene diisocyanate and isophorone diisocyanate are used.

Examples of suitable compounds (a2) are the monoesters of (a21) Diols and polyols which preferably contain 2 to 20 carbon atoms and at least 2 hydroxyl groups in the molecule, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,1-dimethyl-1,2 ethanediol, dipropylene glycol, tripropylene glycol, tetraethylene glycol, pentaethylene glycol, 1, 4-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol,

2-Methyl-1, 5-pentanediol, 2-ethyl-1,4-butanediol, 1,4-dimethylolcyclohexane, 2,2-bis (4-hydroxycyclohexyl) propane, glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, ditrimethylolpropane , Erythritol, sorbitol, polytetrahydrofuran having an average molecular weight of 162 to 2,000, poly-1,3-propanediol having an average molecular weight of 134 to 400 or

Polyethylene glycol having a molecular weight between 150 and 500, in particular ethylene glycol; With

(a22) alpha, beta-unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, acrylamidoglycolic acid,

Methacrylamidoglycolic acid, especially acrylic acid.

Further examples of suitable compounds (a2) are the monovinyl ethers of the above-described diols and polyols (a21).

Further examples of suitable compounds (a2) are the monoesters or monoamides of the above-described alpha, beta-unsaturated carboxylic acids (a22) with

(a23) amino alcohols, such as 2-aminoethanol, 2- (methylamino) ethanol, 3-amino-1-propanol, 1-amino-2-propanol or 2- (2-aminoethoxy) ethanol,

(a24) thioalcohols, such as 2-mercaptoethanol, or

(a25) polyamines, such as ethylenediamine or diethylenetriamine.

In particular, 2-hydroxyethyl acrylate is used.

Examples of suitable compounds (a3) are

(a31) hydroxycarboxylic acids, such as hydroxyacetic acid (glycolic acid), 2- or 3-hydroxypropionic acid, 3- or 4-hydroxybutyric acid, hydroxypivalic acid, 6-hydroxycaproic acid, citric acid, malic acid, tartaric acid, 2,3- Dihydroxypropionic acid (glyceric acid), dimethylolpropionic acid,

Dimethylol butyric acid, trimethylolacetic acid, salicylic acid, 3- or 4-hydroxybenzoic acid or 2-, 3- or 4-hydroxycinnamic acid,

(a32) amino acids such as 6-aminocaproic acid, aminoacetic acid (glycine), 2-aminopropionic acid (alanine), 3-aminopropionic acid (beta-alanine) or the other essential amino acids; N, N-bis (2-hydroxyethyl) glycine, N- [bis (hydroxymethyl) methyl] glycine or imidodiacetic acid,

(a33) sugar acids, such as gluconic acid, glucaric acid, glucuronic acid, galacturonic acid or mucic acid (galactaric acid),

(a34) thiolcarboxylic acids, such as mercaptoacetic acid, or

(a35) sulfonic acids, such as 2-aminoethanesulfonic acid (taurine), aminomethanesulfonic acid,

aminopropane sulfonic acid,

2- [4- (2-hydroxyethyl) -1-piperazinyl] ethanesulfonic acid,

3- [4- (2-hydroxyethyl) piperazinyl] propanesulfonic acid,

N- [tris (hydroxymethyl) methyl] -2-aminoethanesulfonic acid, N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid, 5-sulfosalicylic acid,

8-hydroxyquinoline-5-sulphonic acid, phenol-4-sulphonic acid or sulphanilic acid.

In particular, hydroxyacetic acid (glycolic acid) (a31) is used.

The acid groups can be ionized.

Examples of suitable counterions are lithium, sodium, potassium, rubidium, cesium, magnesium, strontium, barium or ammonium ions and primary, secondary, tertiary or quaternary ammonium ions, which are derived from customary and known organic amines.

Examples of suitable compounds (a4) are the above-described compounds diols and polyols (a21), amino alcohols (a23), thioalcohols (a24) or polyamines (a25).

Preferably, for the preparation of the urethane (meth) acrylates (A1), the compounds (a1), (a2) and (a3) and optionally (a4) are reacted in a molar ratio with each other to 3 equ. Isocyanate groups from the compound (a1) 0.5 to 3, preferably 0.8 to 2.5, particularly preferably 1, 0 to 2.2 and in particular 1, 4 to 1, 8 equ. isocyanate-reactive functional groups from the compound (a2) and

- 0.001 to 1, 5, preferably 0.005 to 1, 0, particularly preferably 0.01 to 0.8 and in particular 0.1 to 0.5 equ. isocyanate-reactive functional groups from the compound (a3) and optionally

0 to 2, preferably 0.1 to 1, 8, particularly preferably 0.5 to 1, 5 and in particular 0.8 to 1, 3 equ. isocyanate-reactive functional groups from the compound (a4)

come.

From a methodological point of view, the preparation of the urethane (meth) acrylates (A1) has no special features, but takes place under the customary and known conditions of the reaction of polyisocyanates with the exclusion of water at temperatures of 5 to 100 ^° C. To a polymerization of the olefinically unsaturated To inhibit double bonds is preferably carried out under an oxygen-containing gas, in particular under air or air-nitrogen mixtures.

The slurry of the invention consists of at least one disperse phase (A) and a continuous aqueous phase (B). In the simplest case, the disperse phase (A) consists of the binder (A1) and the continuous phase (B) of water. Preferably, however, the slurry according to the invention also contains at least one customary and known additive (A2) in customary and known amounts.

Depending on its physicochemical properties, an additive (A2) may be present in the disperse phase (A), ie the dimensionally stable particles (A); but it can also form a separate disperse phase (A2), such as a pigment. In addition, it may be exclusively in the aqueous phase (B), such as a water-soluble salt, or may accumulate in the interface between aqueous phase (B) and disperse phase (A), such as a wetting agent. Last but not least, the additive (A2) can be distributed between the disperse phase (A) and the aqueous phase (B), such as, for example, a molecularly dispersed organic dye. The person skilled in the art can therefore easily predict how an additive (A2) will behave in the slurry according to the invention. Preferably, the additive (A2) from the group consisting of residue-free or substantially residue-free thermally decomposable salts; binders which are physically, thermally and / or actinically radiation-curable with respect to the binders (B); Neutralizing agents; thermally curable reactive diluents; curable with actinic radiation reactive diluents; opaque and transparent, color and / or effect pigments; molecularly soluble dyes; opaque and transparent fillers; nanoparticles; Light stabilizers; antioxidants; Venting means; Wetting agents; emulsifiers; slip additives; polymerization inhibitors; Initiators of radical polymerization, especially photoinitiators; thermolabile radical initiators; Adhesion promoters; Leveling agents; film-forming aids; Rheology auxiliaries, such as thickeners and pseudoplastic Sag control agents, SCA; Flame retardants; Corrosion inhibitors; anti-caking agents; To grow; driers; Biocides and matting agents; selected.

The slurry according to the invention preferably contains residue-free or essentially residue-free, thermally decomposable salts, light stabilizers, wetting agents, emulsifiers, leveling agents, photoinitiators and rheological aids as additives (A2).

Preferably, the slurry according to the invention, if it is to be used as a clearcoat slurry, contains no opaque constituents, in particular no opaque pigments and fillers.

Examples of suitable additives (A2) are from the German patent applications

DE 101 26 649 A1, page 16, paragraph [0145], to page 18, paragraph [0189],

DE 100 27 270 A1, page 11, paragraphs [0106] and [0107] or

- DE 101 35 997 A1, page 3 [0022] to page 4, paragraph [0033], and page 4, paragraphs

[0039] and [0040], page 10, paragraphs [0092] to [0101],

known.

If the inventive slurry contains thermally curable constituents, they are preferably present in the dimensionally stable particles (A) in an amount of <40% by weight, preferably <30% by weight and in particular <20% by weight. The slurry according to the invention is preferably prepared by the secondary dispersion process known from German Patent Application DE 199 08 013 A1, German Patent DE 198 41 842 C2 or German Patent Application DE 100 55 464 A1.

In this process, the ionically stabilizable binders (A1) and optionally the additives (A2) are dissolved in organic solvents, in particular readily volatile, water-miscible solvents. The resulting solutions are dispersed in water with the aid of neutralizing agents (A2). Then it is diluted with water while stirring. It initially forms a water-in-oil emulsion, which turns on further dilution in an oil-in-water emulsion. This point is generally reached at solids contents of <50% by weight, based on the emulsion, and is externally evident from a greater decrease in viscosity during dilution.

The oil-in-water emulsion can also be prepared directly by the melt emulsification of the binders (A1) and optionally the additives (A2) in water.

It is advantageous if the wetting agents (A2) are added to the organic solution and / or the water before or during the emulsification. Preferably, they are added to the organic solution.

The solvent-containing emulsion thus obtained is subsequently freed of solvents by azeotropic distillation.

According to the invention it is advantageous if the removal-solvent at a distillation temperature below 70 ° C, preferably below 50 ⁰ C and are distilled in particular below 40 ^0C. Optionally, the distillation pressure is chosen so that this temperature range is maintained at higher boiling solvents.

In the simplest case, the azeotropic distillation can be accomplished by stirring the emulsion at room temperature in an open vessel for several days. In the preferred case, the solvent-containing emulsion is freed from the solvents by vacuum distillation.

The evaporated or distilled off amount of water and solvents are replaced by water to avoid high viscosities. The addition of the water can before, after or during the evaporation or distillation by adding in portions.

After loss of the solvents, the glass transition temperature of the dispersed dimensionally stable particles increases, and instead of the previous solvent-containing emulsion, the pseudoplastic aqueous dispersion (B) is formed, i. the inventive slurry (A), from.

Optionally, the dimensionally stable particles are mechanically comminuted in the wet state, which is also referred to as wet milling. Preferably conditions 60 and in particular 5O ⁰ C in this case be applied so that the temperature of the ground material 70 preferably does not exceed. The specific energy input during the milling process is preferably 10 to 1000, preferably 15 to 750 and in particular 20 to 500 Wh / g.

For wet grinding, a wide variety of devices can be used which produce high or low shear fields.

Examples of suitable devices which produce low shear fields are customary and known stirred tanks, gap homogenizers, microfluidizers or dissolvers.

Examples of suitable devices which produce high shear fields are conventional and known stirred mills or inline dissolvers.

Most preferably, the devices that produce high shear fields are used. Of these, the agitator mills according to the invention are particularly advantageous and are therefore used with very particular preference.

In general, during wet grinding, the slurry according to the invention is fed by means of suitable devices, such as pumps, in particular gear pumps, to the devices described above and driven in a circle over this until the desired particle size is reached.

Preferably, the slurry of the invention is filtered before use. For this purpose, the usual and known filtration devices and filters are used. The

Mesh size of the filter can vary widely and depends primarily on the

Particle size and the particle size distribution of the particles. The expert can therefore the easily determine the appropriate filter based on this physical parameter. Examples of suitable filters are monofilament surface filters or bag filters. These are available on the market under the brands Pong® or Cuno®.

The slurry according to the invention can be prepared in an outstanding manner by means of the customary and known methods of applying liquid coating materials, such as e.g. Spraying, spraying, knife coating, brushing, pouring, dipping, trickling or rolling, apply. Preferably, spray application methods are used. Preferably, actinic radiation is excluded.

After its application, the slurry according to the invention dries without problems and shows filming at the processing temperature, generally at room temperature. In other words, the slurry of the invention applied as a wet layer releases at room temperature or slightly elevated temperatures with release of water, the particles contained therein changing their original shape, flowing together and forming a homogeneous film (A). However, the applied slurry according to the invention can also dry in powder form.

The drying may be accelerated by the use of a gaseous, liquid and / or solid hot medium such as hot air, heated oil or heated rolls, or microwave, infrared and / or near infrared (NIR) light. Preferably, the wet layer is dried in a circulating air oven at 23 to 150 ° C, preferably 30 to 120 ⁰ C and in particular 50 to 100 ⁰ C dried.

Subsequently, the dried layer (A) according to the invention is cured by free-radical polymerization.

The radical polymerization can be thermally initiated and maintained. Preferably, the devices and methods described above are used. In some cases, it may be advantageous to run the leveling process and the curing or crosslinking reaction with a time lag by running a step heating program or a so-called heat ramp. The crosslinking temperature is preferably between 120 and 160 ^° C. The corresponding burn-in time is between 10 and 60 minutes.

The free-radical polymerization is preferably initiated and maintained with actinic radiation, preferably electron radiation or UV radiation, preferably UV radiation, in particular UV irradiation. Methodically, the curing with actinic radiation has no special features, but can with the help of the usual and known devices and methods, as described for example in German Patent Application DE 198 18 735 A 1, column 10, lines 31 to 61, the German patent application DE 102 02 565 A1, page 9, paragraph [0092], to page 10, paragraph [0106], German patent application DE 103 16 890 A1, page 17, paragraphs [0128] to [0130], in the international patent application WO 94 / 11123, page 2, lines 35, to page 3, line 6, page 3, lines 10 to 15, and page 8, lines 1 to 14, or US Pat. No. 6,743,466 B2, column 6, line 53, to column 7 , Line 14, are described.

Preferably, the cure is combined with actinic radiation with the thermal cure.

Because of the advantageous properties of the slurry according to the invention and of the cured materials produced therefrom according to the invention, the slurry according to the invention and the materials according to the invention can be used extremely widely. Preferably, they are used as coating materials, adhesives and sealants for the production of coatings, adhesive layers and seals according to the invention.

The coatings, adhesive layers and seals according to the invention can be used for coating, bonding and sealing a wide variety of coated and uncoated substrates.

Preferably, the substrates of metals, plastics, wood, ceramics, stone, textile, fiber composites, leather, glass, glass fibers, glass and rock wool, mineral and resin-bound building materials, such as gypsum and cement boards or roof tiles, and composites of these materials.

Preferably, the substrates are um

by land, sea or air powered by force of muscle, hot air or wind, such as bicycles, trolleys, rowing boats, sailboats, hot air balloons, gas balloons or gliders, and parts thereof Motor powered means of transport by land, sea or air, such as motorcycles, commercial vehicles or motor vehicles, in particular cars, over- or

Underwater ships or aircraft, and parts thereof, stationary floats, such as buoys or parts of docks - indoor and outdoor structures,

Doors, windows and furniture and

Hollow glass body, industrial small parts such as screws, nut, hubcaps or rims,

Containers, such as coils, containers or packaging, electrotechnical components, such as electronic winding goods, for example coils, optical components, mechanical components and white goods, such as domestic appliances, boilers and radiators.

In particular, the substrates are car bodies and parts thereof.

The slurry according to the invention is preferably used for the production of the coatings according to the invention.

The slurry according to the invention can be used with particular advantage as a primer, primer, filler, basecoat, solid-color topcoat and clearcoat to produce one-coat or multi-coat primer finishes, anticorrosion coatings, antistonechip primers, surfacer finishes, basecoats, solid-color topcoats and clearcoats.

With very particular advantage, the slurry according to the invention is used for the production of clearcoats in the context of multicoat color and / or effect paint systems, in particular by the customary and known wet-on-wet processes (cf., German Patent Application DE 100 27 292 A1 , Page 13, paragraph [0109], to page 14, paragraph [0118]) are prepared from basecoats and the slurry according to the invention.

Because of their particular advantages, the inventive slurry and the clearcoats of the invention prepared therefrom are outstandingly suitable for the original coating of passenger cars (OEM) and for the repair of car paint finishes, in particular finishes of passenger cars of the upper class. In this case, the repair small area, for example, as a spot repair, or large area both the car manufacturer in the line, for example, as an end-of-line repair, as well as in the paint shop done. Before repair, the damaged surfaces can be pretreated in the area of the areas to be repaired. This can be done for example by dissolving the surface with an organic solvent, heads, grinding, corona treatment or flame treatment. It is a particular advantage of the slurry according to the invention that in many cases such pretreatments can be dispensed with.

The multicoat color and / or effect coating systems according to the invention which comprise at least one clearcoat according to the invention fulfill all the requirements which are imposed on automotive finishes (see European Patent EP 0 352 298 B1, page 15, lines 42, to page 17, line 40) ) and fully conform to the appearance of a Class A surface. In particular, they are particularly smooth, even in high layer thicknesses free from paint defects such as craters or cracks, weather-resistant, chemical-resistant, resistant to condensation, resistant to stone chips, and scratch-resistant.

Examples

Production Example 1

The preparation of a binder (A1)

Isopropenylidenedicyclohexanol was coarsely dispersed in hydroxyethyl acrylate at 60 ^° C. with stirring. To this suspension were added the polyisocyanates, pentaerythritol tri / tetra-acrylate, hydroquinone monomethyl ether, 1,6-di-tert-butyl-p-cresol and methyl ethyl ketone. Upon addition of dibutyltin dilaurate, the reaction mixture warmed. The mixture was stirred at 75 ° C for several hours until the content of free isocyanate groups was constant. Then glycolic acid and methanol were added and stirred until no more free isocyanate groups were detectable.

The hydroxyl-containing compounds and the polyisocyanates were used in amounts that gave the following equivalent ratios:

Isopropenylidenedicyclohexanol 33.7 equ. OH

2-hydroxyethyl acrylate 24.7 equ. OH Pentaerythritol tri / tetra-acrylate (average OH number: 100 to 111 mg KOH / g) 24.7 equ. OH

Basonat® HI 100 from BASF AG 56.25 equ. NCO

Allophanate from hexamethylene diisocyanate and 2-hydroxyethyl acrylate according to international patent application WO 00/39183 18,75 equ. NCO

Desmodur® W from Bayer Aktiengesellschaft 25 equ. NCO

Hydroquinone monomethyl ether 0.05 wt .-%, based on the solids

1, 6-di-tert-butyl-p-cresol 0.1 wt .-%, based on the solids

Methyl ethyl ketone corresponding to a solids content of 70 wt .-% in

Dibutyltin dilaurate 0.02 wt .-%, based on the solids

Glycolic acid 6.8 equ. OH

Methanol 10.1 equ. OH

The resulting binder (A1) had a glass transition temperature of 2.5 ° C, a viscosity at 23 ° C of 2.0 Pas, a content of olefinically unsaturated double bonds of 3.12 equiv. / kg solids and an acid number of 11, 41 mg KOH / g solids on. It was excellently suited for the production of clearcoat slurries.

example 1

The preparation of a clearcoat slurry 738.165 parts by weight of the solution of the binder (A1) according to Preparation Example 1, 10.438 parts by weight of a 50 percent solution of Tinuvin® CGL 052 (light stabilizer from Ciba Specialty Chemicals, containing one triazine group and two cyclic, sterically hindered amino ether groups) in methyl ethyl ketone, 9.185 parts by weight of Tinuvin ® 400 (light stabilizer from Ciba Specialty Chemicals), 7.228 parts by weight of Lutensol® AT 50 (wetting agent from BASF AG), 8.246 parts by weight of trimethylamine, 20.876 parts by weight of a mixture of the photoinitiators Irgacure® 184 from Ciba Specialty Chemicals and Lucirin® TPO from BASF AG (weight ratio 5: 1) were mixed together. The resulting mixture was dispersed in 1004 parts by weight of deionized water. To this dispersion was added 0.171 parts by weight of ammonium acetate. The degree of neutralization of the binder (B1) was 75%. Subsequently, dispersion was filtered through a filter 1 μm Cuno® white.

The filtered dispersion was stirred for 24 hours at room temperature in an open vessel to evaporate the methyl ethyl ketone.

The solvent-free dispersion was completed with 0.788 parts by weight of Baysilone® AI 3468 (leveling agent from Borchers) and 15.776 parts by weight of Acrysol® RM-8W (nonionic associative thickener from Rohm & Haas).

The mean particle size z-mean of the resulting clearcoat slurry was measured by means of photon correlation spectroscopy (Malvern Zetasizer® 1000); it was 140 nm.

The clearcoat slurry had a solids content of 36.2% by weight. It was outstandingly suitable for the production of color and / or effect multicoat paint systems for passenger cars.

Example 2

The production of multicoat colorant coatings

For the preparation of multicoat color finishes Steel sheets were used as test panels, which had been coated with a customary and known cathodically deposited and baked electrodeposition coating. On the electrodeposition paints were each a layer of a conventional and known wet filler of BASF Coatings AG and a layer of a conventional and well-known black water-based paint from BASF Coatings AG applied wet-on-wet. After their application, the layers were each pre-dried for 10 minutes at 80 ⁰ C.

Subsequently, the clearcoat slurry of Example 1 was applied to the dried basecoat film in wedge form, so that after drying the resulting clearcoat film and the joint curing of the surfacer coat, the basecoat film and the clearcoat film resulted in a wedge-shaped clearcoat a layer thickness of 10 to 100 microns. The curing itself was carried out thermally for 15 minutes at 155 ° C and with UV radiation of a dose of 1, 5 J / cm ² (iron-doped mercury vapor lamp from the company IST) under an oxygen-depleted atmosphere (1 vol .-% oxygen). The clearcoat was free of craters, mud cracking and micro-disturbances (starry sky) even with a layer thickness> 80 μm.

In addition, the clearcoat slurry of Example 1 was applied to the dried basecoat film in a uniform layer thickness, so that after drying the resulting clearcoat film and the joint curing of the surfacer coat, the basecoat film and the clearcoat film resulted in a clearcoat of a film thickness of 40 microns. The curing itself was also carried out here thermally for 15 minutes at 155 ° C in a convection oven and with UV radiation of a dose of 1, 5 J / cm ² (iron-doped mercury vapor lamp from the company IST) under an oxygen-depleted atmosphere (1 vol .-% oxygen) ,

The resulting black multicoat paint systems were particularly brilliant, glossy, chemical-resistant, impact-resistant, hard, flexible, scratch-resistant and resistant to condensation, which could be substantiated by the following test results:

Chemikalienbeständiqkeit:

DaimlerChrysler gradient oven test

Test substance visible damage

Sulfuric acid: 44 ^° C.

NaOH: 48 ° C

Tree resin:> 75 ° C

Deionized water:> 75 ° C Condensation:

Constant climate test (KK 240 h)

Bubble amount: 0

Size: 0

Note: low swelling, slight blushing

Crosshatch test with

Tesaband outline: GT-1

Hardness:

Fisher Scope indentation:

Universal hardness: 137.4 N / mm ² at 25.6 mN average penetration depth: 2.66 μm relative elastic depth resilience: 64.5%

Creep at 25.6 mN: 10.74%

Creep at 0.4 mN: 33.64%

Rockfall:

VDA:

Characteristic value: 1, 5 rust degree: 0,5

Bullet shot: all right

Kratzfestiqkeit:

Laboratory washer according to Amtec-Kistler: initial gloss (20 °): 89 units

Residual gloss without cleaning: 65 units Residual gloss after cleaning: 71 units Residual gloss: 81%

Sand test (see German patent application DE 198 39 453 A1, page 9, lines 1 to 63): residual gloss: 84%

Claims

claims

1. By radical polymerization curable, aqueous, pseudoplastic, completely or substantially free of volatile organic compounds powder dispersions, containing as disperse phase solid and / or high viscosity under storage and

Conditions of use Dimensionally stable particles (A) with a mean particle size z-mean measured by photon correlation spectroscopy of 80 to 750 nm, wherein the particles (A) at least one free-radically crosslinkable binder (A1) with a glass transition temperature of -70 to + 50 ° C, a Content of olefinically unsaturated double bonds of 2 to 10 equ./kg and one

Content of acid groups from 0.05 to 15 equ./kg in an amount of, based on (A), 50 to 100 wt .-%.

2. powder dispersions according to claim 1, characterized in that the binder (A1) has a number average molecular weight of 1,000 to 50,000 daltons.

3. powder dispersions according to claim 1 or 2, characterized in that the olefinically unsaturated double bonds in groups selected from the group consisting of (meth) acrylate, ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester, Dicyclopentadienyl- , Norbornyl, isoprenyl, isopropenyl, allyl or

butenyl; Dicyclopentadienyl, norbomenyl, isoprenyl, isopropenyl, allyl or butenyl ether groups or dicyclopentadienyl, norbornyl, isoprenyl, isopropenyl, allyl or butenyl ester groups.

4. Powder dispersions according to claim 3, characterized in that the olefinically unsaturated double bonds are present in (meth) acrylate groups.

5. powder dispersions according to one of claims 1 to 4, characterized in that the binder (A1) from the group consisting of oligomeric and polymeric epoxy (meth) acrylates, urethane (meth) acrylates and carbonate (meth) acrylates are selected.

6. powder dispersions according to claim 5, characterized in that the binder (A1) is an oligomeric or polymeric urethane (meth) acrylate.

7. powder dispersions according to one of claims 1 to 6, characterized in that the dimensionally stable particles (A) with a Photon correlation spectroscopy measured mean particle size z-mean from 80 to 400 nm.

8. Powder dispersions according to one of claims 1 to 7, characterized in that they contain at least one additive (B2) selected from the group consisting of residue-free or substantially residue-free thermally decomposable salts; binders which are physically, thermally and / or actinically radiation-curable with respect to the binders (B);

Neutralizing agents; thermally curable reactive diluents; curable with actinic radiation reactive diluents; opaque and transparent, color and / or effect pigments; molecularly soluble dyes; opaque and transparent fillers; nanoparticles; Light stabilizers; antioxidants;

Venting means; Wetting agents; emulsifiers; slip additives;

polymerization inhibitors; Initiators of radical polymerization, especially photoinitiators; thermolabile radical initiators; Adhesion promoters;

Leveling agents; film-forming aids; Rheology auxiliaries, such as thickeners and pseudoplastic Sag control agents, SCA; Flame retardants; Corrosion inhibitors;

anti-caking agents; To grow; driers; Biocides and matting agents; contain.

9. A process for the preparation of radically polymerizable, aqueous, pseudoplastic, volatile organic compounds completely or substantially free powder dispersions according to one of claims 1 to 8, characterized in that the particles (A) in an aqueous medium (B) dispersed.

10. The method according to claim 10, characterized in that dispersing the particles (A) in an aqueous medium (B) by a secondary dispersion process, wherein

- The ionically stabilizable binder (A1) and optionally the

Dissolves additives (A2) in organic solvents,

the resulting solutions are dispersed in water with the aid of neutralizing agents (A2), the resulting dispersion is diluted with water, which initially forms a water-in-oil emulsion, which turns on further dilution in an oil-in-water emulsion, and

- The organic solvents removed from the oil-in-water emulsion.

11. Use of free radical-curable, aqueous, pseudoplastic, completely or substantially free from volatile organic compounds powder dispersions according to any one of claims 1 to 8 and prepared by the method according to claim 9 or 10 by free-radical

Polymerization of curable, aqueous, pseudoplastic, of volatile organic compounds completely or substantially free powder dispersions as coating materials, adhesives and sealants for the production of coatings, adhesive layers and seals.

12. Use according to claim 1 1, characterized in that the coating materials are used as primers, primers, fillers, basecoats, solid color topcoats and clearcoats for the production of single or multi-layer primer coatings, anticorrosion coatings, antistonechip primers, surfacer finishes, basecoats, solid-color topcoats and clearcoats.

13. Use according to claim 12, characterized in that the clearcoats serve for the production of single-coat or multi-coat clearcoats in the context of multicoat color and / or effect paint systems.

14. Use according to claim 13, characterized in that the color and / or effect multi-layer coatings are prepared by means of wet-on-wet process.

15. Use according to one of claims 11 to 14, characterized in that the free-radical polymerization is initiated and maintained thermally and / or with actinic radiation.