DE19927597B4 - Water-dilutable binders and use thereof - Google Patents

Abstract

Water-dilutable binders for the preparation of thixotropic aqueous paints, characterized in that the rheology control agent is prepared by
(A) 20 to 90 wt .-% of a mixture of
(a1) from 3 to 50% by weight of acrylic acid, methacrylic acid or a mixture of acrylic acid and methacrylic acid and
(a2) from 50 to 97% by weight of an ethylenically unsaturated monomer other than (a1) or a mixture of such ethylenically unsaturated monomers,
in the presence of
(B) 9.9 to 79.9 wt .-% of a chlorine-containing polyolefin having a chlorine content of 1 to 50 wt .-%, based on the polyolefin, and
C) 0.1 to 10 wt .-% of a radical generator or a mixture of radical formers
are polymerized free-radically and the resulting polymerization after dispersion of at least 20% of the carboxyl groups contained in the polymerization is dispersed in water, the sum of the weight percentages for components (A), (B) and (C) and (a1) and (a2 ) always gives 100 wt .-% and the composition of the ...

Description

Territory of invention

The The invention relates to water-dilutable binders and their use.

State of technology

The Application properties of aqueous Lacquers and the appearance of the applied paint films are decisively influenced by the rheological properties of the varnish. For aqueous paints, preferably by spraying must be applied special, due to the specific evaporation behavior of Water, from rheology additives for solvent-based Lacke distinguishing, rheology additives are used.

The Rheology of the aqueous Paints should be so be prepared that the paint at low shear rates a high viscosity and at high shear rates a low viscosity, ie thixotropic behavior having. The high viscosity For example, at low shear rates is necessary to sediment the solid particles in the paint and to prevent the formation of sacks. The low viscosity at high Shear rate is particular for the spray application the paints important. Furthermore, the varnishes should have low elasticity at high shear rates exhibit.

In EP-A-0 399 442 describes rheological additives for aqueous paints which from a combination of hydrophilic, colloidal silica and a water-soluble or wasserdis pergierbaren fluorohydrocarbon polymer which 2 to 25 wt .-% fluorine, based on the fluorohydrocarbon polymer, consist, contains. The fluorohydrocarbon polymers and in particular their monomeric starting materials are ecologically very questionable and are increasingly being substituted.

The German patent application DE-OS 44 12 655 comprises water-dilutable binders, prepared by polymerization of component (A) consisting of (a1) acrylic and / or methacrylic acid, in Presence of (B) a halogen-free polyolefin and (C) a Radical generator. Aqueous paints, which contain these binders become the primer or the single-layer coating of plastics used. The in DE-OS 44 12 655 paint systems have all the advantages described there Disadvantages in rheological behavior, in particular occur the application sedimentation problems and Sacker on.

In the German patent application DE-OS building on DE-OS 44 12 655 195 38 147 become water-dilutable Binders prepared by polymerization of the above described component (A) in the presence of a specific Olefincopolymersiats (B) and a radical generator (C), which is also the primer or used for the single-coat coating of plastics. Again, the already described rheology-related problems occur in the paint application on.

DE-A-43 27,468 a process for painting plastics using a Coating agent, which in addition to a one- or two-component binder at least one adhesion promoter (a) in an amount of from 1 to 25% by weight, based on the binder, wherein the adhesion promoter (a) a chemically modified polyolefin having a weight average Mw of 10,000 to 100,000 daltons, a nonuniformity from 1.0 to 6.5 and a chlorine content of from 2.5 to 50% by weight, characterized in that as a further auxiliary OH-functional, hydrophobic esters of (i) polyhydric alcohols and (ii) aliphatic C8 to C22 monocarboxylic acid with an OH number of From 50 to 600 in an amount of from 20 to 80% by weight, based on (a), used. In addition to these adhesion promoters are in DE-A-43 27 468 still common Rheology aids used.

Task and solution

The technical problem underlying the present invention consists in the further improvement of the rheological properties of in DE-OS 44 12 655 and DE-OS 195 38 147 described water-dilutable binders and aqueous paints containing these binders and which can be used in processes for the primer or single-coat paint of plastics. On the one hand, the use of ecologically questionable fluorohydrocarbon polymers, on the other hand, the use of conventional rheological aids, especially based on phyllosilicates, which lead to problems in the water resistance of the coating films and their incorporation is complicated, should be avoided.

• (A) 20 bis 90 Gew.-%, vorzugsweise 55 bis 85 Gew.-% einer Mischung aus (a1) 3 bis 50 Gew.-%, vorzugsweise 5 bis 20 Gew.-% Acrylsäure, Methacrylsäure oder einer Mischung aus Acrylsäure und Methacrylsäure und (a2) 50 bis 97 Gew.-%, vorzugsweise 85 bis 95 Gew.-%, eines von (a1) verschiedenen, ethylenisch ungesättigten Monomeren oder einer Mischung auf solchen ethylenisch ungesättigten Monomeren, in Gegenwart von
• (B) 9,9 bis 79,9 Gew.-%, vorzugsweise 15 bis 45 Gew.-% eines chlorhaltigen Polyolefins mit einem Chlorgehalt von 1 bis 50 Gew.-%, bezogen auf das Polyolefin, und
• (C) 0,1 bis 10 Gew.-%, vorzugsweise 1 bis 7 Gew.-% eines Radikalbildners oder einer Mischung aus Radikalbildnern

radikalisch polymerisiert werden und das erhaltene Polymerisationsprodukt nach Neutralisation von mindestens 20 % der in dem Polymerisationsprodukt enthaltenen Carboxylgruppen in Wasser dispergiert wird, wobei die Summe der Gewichtsprozentangaben für die Komponenten (A), (B) und (C) sowie (a1) und (a2) jeweils stets 100 Gew.-% ergibt und die Zusammensetzung der Mischung aus (a1) und (a2) so ausgewählt wird, daß bei alleiniger Polymerisation der Mischung aus (a1) und (a2) ein Polymerisat erhalten wird, das

• – eine Glasübergangstemperatur von 0 bis 150 Grad C, vorzugsweise 10 bis 80 Grad C aufweist,
• – 0,04 bis 1,0, vorzugsweise 0,1 bis 0,5 Milliäquivalente einer oder mehrerer der folgenden funktionellen Gruppen enthält: -COOH, -OH, -NR₃, -CN, -CONH₂, -CO-, -NHCONH-, -OCONH-, -OPO₃H, -OSO₃H, -R-O-R-, vorzugsweise -COOH, -CN, -CNH₂ und -R-O-R, wobei R für einen organischen Rest steht, vorzugsweise für einen Alkyl- bzw. Alkylenrest mit 1 bis 6 C-Atomen, und
• – das zu 0 bis 50, vorzugsweise 5 bis 25 Gew.-% aus einer oder mehreren der folgenden cycloaliphatischen Gruppen, die mit mindestens einer Alkylgruppe, die 1 bis 12, vorzugsweise 1 bis 6 C-Atome enthält, substituiert sein können, besteht: Cyclopentyl-, Cyclohexyl-, Perhydronaphthyl-, Perhydroanthracyl-, Perhydrophenanthryl-, Adamantyl-, Isobornyl-, Bicyclohexyl-, Bicycloheptyl-, Bicyclooctyl-, Bicyclononyl-, Bicyclodecyl-, Bicycloundecyl- und Bicyclododecylgruppe, vorzugsweise Cyclohexyl- und Isobornylgruppe, besonders bevorzugt Cyclohexylgruppen und/oder Isobornylgruppen.

This object is surprisingly achieved by the provision of water-dilutable binders which are obtainable in that

• (A) 20 to 90 wt .-%, preferably 55 to 85 wt .-% of a mixture of (a1) 3 to 50 wt .-%, preferably 5 to 20 wt .-% acrylic acid, methacrylic acid or a mixture of acrylic acid and Methacrylic acid; and (a2) 50 to 97% by weight, preferably 85 to 95% by weight, of an ethylenically unsaturated monomer other than (a1) or a mixture of such ethylenically unsaturated Mo. nomeren, in the presence of
• (B) 9.9 to 79.9 wt .-%, preferably 15 to 45 wt .-% of a chlorine-containing polyolefin having a chlorine content of 1 to 50 wt .-%, based on the polyolefin, and
• (C) 0.1 to 10 wt .-%, preferably 1 to 7 wt .-% of a radical generator or a mixture of radical formers

are polymerized free-radically and the resulting polymerization after dispersion of at least 20% of the carboxyl groups contained in the polymerization is dispersed in water, the sum of the weight percentages for components (A), (B) and (C) and (a1) and (a2 ) always gives 100 wt .-% and the composition of the mixture of (a1) and (a2) is selected so that when polymerizing the mixture of (a1) and (a2) alone, a polymer is obtained which

• Has a glass transition temperature of 0 to 150 degrees C, preferably 10 to 80 degrees C,
• Contains from 0.04 to 1.0, preferably from 0.1 to 0.5, milliequivalents of one or more of the following functional groups: -COOH, -OH, -NR ₃ , -CN, -CONH ₂ , -CO-, -NHCONH -, -OCONH-, -OPO ₃ H, -OSO ₃ H, -ROR-, preferably -COOH, -CN, -CNH ₂ and -OR, wherein R is an organic radical, preferably an alkyl or alkylene radical with 1 to 6 C atoms, and
• - which may be substituted by 0 to 50, preferably 5 to 25 wt .-% of one or more of the following cycloaliphatic groups which may be substituted with at least one alkyl group containing 1 to 12, preferably 1 to 6 C-atoms, consists of: Cyclopentyl, cyclohexyl, perhydronaphthyl, perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl, bicycloundecyl and bicyclododecyl, preferably cyclohexyl and isobornyl, more preferably cyclohexyl and / or isobornyl groups.

The binder components

• (a1) 3 bis 50 Gew.-%, vorzugsweise 5 bis 20 Gew.-% Acrylsäure, Methacrylsäure oder einer Mischung aus Acrylsäure und Methacrylsäure und
• (a2) 50 bis 97 Gew.-%, vorzugsweise 85 bis 95 Gew.-% eines ethylenisch ungesättigten Monomeren oder einer Mischung aus ethylenisch ungesättigten Monomeren,

wobei die Summe der Gewichtsprozentangaben für die Komponenten (a1) und (a2) stets 100 Gew.-% ergibt und die Zusammensetzung der Mischung aus (a1) und (a2) so ausgewählt wird, daß bei alleiniger Polymerisation der Mischung aus (a1) und (a2) ein Polymer erhalten wird, das

• – eine Glasübergangstemperatur von 0 bis 150 Grad C, vorzugsweise 10 bis 80 Grad C aufweist,
• – 0,04 bis 1,0, vorzugsweise 0,1 bis 0,5 Milliäquivalente einer oder mehrerer der folgenden funktionellen Gruppen enthält: -COOH, -OH, -NR₃, -CN, -CONH₂, -CO-, -NHCONH-, -OCONH-, -OPO₃H, -OSO₃H, -R-O-R-, vorzugsweise -COOH, -CN, -CNH₂ und -R-O-R-, wobei R für einen organischen Rest steht, vorzugsweise für einen Alkyl- bzw. Alkylenrest mit 1 bis 6 C-Atomen, und
• – das zu 0 bis 50, vorzugsweise 5 bis 25 Gew.-% aus einer oder mehreren der folgenden cycloaliphatischen Gruppen, die mit mindestens einer Alkylgruppe, die 1 bis 12, vorzugsweise 1 bis 6 C-Atome enthält, substituiert sein können, besteht: Cyclopentyl-, Cyclohexyl-, Perhydronaphthyl-, Perhydroanthracyl-, Perhydrophenanthryl-, Adamantyl-, Isobornyl-, Bicyclohexyl-, Bicycloheptyl-, Bicyclooctyl-, Bicyclononyl-, Bicyclodecyl-, Bicycloundecyl- und Bicyclododecylgruppe, besonders bevorzugt Cyclohexyl- und/oder Isobornylgruppen.

The mixture (A) used for the preparation of the inventive water-dilutable binder medium consists
out

• (a1) 3 to 50 wt .-%, preferably 5 to 20 wt .-% acrylic acid, methacrylic acid or a mixture of acrylic acid and methacrylic acid and
• (a2) from 50 to 97% by weight, preferably from 85 to 95% by weight, of an ethylenically unsaturated monomer or a mixture of ethylenically unsaturated monomers,

the sum of the percentages by weight for the components (a1) and (a2) always being 100% by weight and the composition of the mixture of (a1) and (a2) being selected such that upon polymerization of the mixture of (a1) and (a2) a polymer is obtained which

• Has a glass transition temperature of 0 to 150 degrees C, preferably 10 to 80 degrees C,
• Contains from 0.04 to 1.0, preferably from 0.1 to 0.5, milliequivalents of one or more of the following functional groups: -COOH, -OH, -NR ₃ , -CN, -CONH ₂ , -CO-, -NHCONH -, -OCONH-, -OPO ₃ H, -OSO ₃ H, -ROR-, preferably -COOH, -CN, -CNH ₂ and -OR-, where R is an organic radical, preferably an alkyl or Alkylene radical having 1 to 6 carbon atoms, and
• - which may be substituted by 0 to 50, preferably 5 to 25 wt .-% of one or more of the following cycloaliphatic groups which may be substituted with at least one alkyl group containing 1 to 12, preferably 1 to 6 C-atoms, consists of: Cyclopentyl, cyclohexyl, perhydronaphthyl, perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclodecyl, bicycloundecyl and bicyclododecyl groups, more preferably cyclohexyl and / or isobornyl groups.

Tg

= Glasübergangstemperatur des Copolymers in K

Wn

= Gewichtsanteil des n-ten Monomers

Tgn

= Glasübergangstemperatur des Homopolymers aus dem n-ten Monomer

berechnet werden kann und ethylenisch ungesättigte Monomere, die -COOH, -OH, -NR₃, -CN, -CONH₂, -CO-, -NHCONH-, -OCONH-, -OPO₃H, -OSO₃H , -R-O-R- (wobei R für einen organischen Rest steht, vorzugsweise für einen Alkyl- bzw. Alkylenrest mit 1 bis 6 C-Atomen), Cyclopentyl-, Cyclohexyl-, Perhydronaphthyl-, Perhydroanthracyl-, Perhydrophenanthryl-, Ada mantyl-, Isobornyl-, Bicyclohexyl-, Bicycloheptyl-, Bicyclooctyl-, Bicyclononyl-, Bicyclohexyl-, Bicycloundecyl- oder Bicyclododecylgruppen enthalten, im Handel erhältlich sind, kann der Fachmann die Zusammensetzung der Mischung aus den Komponenten (a1) und (a2) ohne Schwierigkeiten so auswählen, daß bei alleiniger Polymerisation der Mischung aus (a1) und (a2) ein Polymer erhalten wird, das

• – eine Glasübergangstemperatur von 0 bis 150 Grad C, vorzugsweise 10 bis 80 Grad C aufweist,
• – 0,04 bis 1,0, vorzugsweise 0,1 bis 0,5 Milliäquivalente einer oder mehrerer der folgenden funktionellen Gruppen enthält: -COOH, -OH-, -NR₃, -CN, -CONH₂, -CO-, -NHCONH-, -OCONH-, -OPO₃H, -OSO₃H, -R-O-R-, vorzugsweise -COOH, -CN, -CNH₂ und -R-O-R-, wobei R für einen organischen Rest steht, vorzugsweise für einen Alkyl- bzw. Alkylenrest mit 1 bis 6 C-Atomen, und
• – das zu 0 bis 50, vorzugsweise 5 bis 25 Gew.-% aus einer oder mehreren der folgenden cycloaliphatischen Gruppen, die mit mindestens einer Alkylgruppe, die 1 bis 12, vorzugsweise 1 bis 6 C-Atome enthält, substitiuert sein können, besteht: Cyclopentyl-, Cyclohexyl-, Perhydronaphthyl-, Perhydroanthracyl-, Perhydrophenanthryl-, Adamantyl-, Isobornyl-, Bicyclohexyl-, Bicycloheptyl-, Bicycloocnyl-, Bicyclononyl-, Bicyclodecyl-, Bicycloundecyl- und Bicyclododecylgruppe, besonders bevorzugt Cyclohexyl- und/oder Isobornylgruppen.

Since the glass transition temperatures of polymers prepared from ethylenically unsaturated monomers are according to the equation

Tg

= Glass transition temperature of the copolymer in K

Wn

= Weight fraction of the nth monomer

tgn

= Glass transition temperature of the homopolymer of the nth monomer

and ethylenically unsaturated monomers, the -COOH, -OH, -NR ₃ , -CN, -CONH ₂ , -CO-, -NHCONH-, -OCONH-, -OPO ₃ H, -OSO ₃ H, -ROR - (wherein R is an organic radical, preferably an alkyl or alkylene radical having 1 to 6 carbon atoms), cyclopentyl, cyclohexyl, perhydronaphthyl, Perhydroanthracyl-, perhydrophenanthryl, Ada mantyl-, isobornyl, bicyclohexyl Those skilled in the art can readily select the composition of the mixture of components (a1) and (a2) so that when used alone, bicycloheptyl, bicyclooctyl, bicyclononyl, bicyclohexyl, bicycloundecyl or bicyclododecyl groups are commercially available Polymerization of the mixture of (a1) and (a2) a polymer is obtained which

• Has a glass transition temperature of 0 to 150 degrees C, preferably 10 to 80 degrees C,
• - 0.04 to 1.0, preferably 0.1 to 0.5 milliequi valente contains one or more of the following functional groups: -COOH, -OH, -NR ₃ , -CN, -CONH ₂ , -CO-, -NHCONH-, -OCONH-, -OPO ₃ H, -OSO ₃ H, -ROR-, preferably -COOH, -CN, -CNH ₂ and -ROR-, where R is an organic radical, preferably an alkyl or alkylene radical having 1 to 6 C atoms, and
• Which may be substituted by 0 to 50, preferably 5 to 25,% by weight of one or more of the following cycloaliphatic groups which may be substituted by at least one alkyl group containing from 1 to 12, preferably from 1 to 6, carbon atoms: Cyclopentyl, cyclohexyl, perhydronaphthyl, perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl, bicyclohexyl, bicycloheptyl, bicycloocynyl, bicyclononyl, bicyclodecyl, bicycloundecyl and bicyclododecyl groups, more preferably cyclohexyl and / or isobornyl groups.

Under consideration The selection criteria described above can be used as component (a2), for example be used: esters of acrylic acid or methacrylic acid, in particular aliphatic and cycloaliphatic acrylates or methacrylates with up to 20 carbon atoms in the alcohol radical, e.g. Methyl, ethyl, Propyl, butyl, hexyl, ethylhexyl, stearyl, lauryl, isobornyl, Cyclohexyl and tert-butylcyclohexyl acrylate or methacrylate, hydroxyalkyl esters of acrylic acid, methacrylic acid or another alpha, beta-ethylenically unsaturated carboxylic acid, such as e.g. 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate or 4-hydroxybutyl methacrylate, corresponding esters of other ethylenic unsaturated Acids with up to 6 C-atoms in the molecule, such as. ethacrylic and crotonic acid, acrylamidomethylpropanesulfonic, vinyl aromatic hydrocarbons, e.g. Styrene, alpha-alkylstyrene and vinyl toluene, amide group-containing monomers, e.g. acrylamide, Methacrylamide, N-methylolacrylamide and N-methylolmethacrylamide and nitrile group-containing monomers, e.g. Acrylic and methacrylonitrile or mixtures of the monomers mentioned.

When Component (B) becomes a chlorine-containing polyolefin or a mixture several chlorine-containing polyolefins used. The chlorine-containing Polyolefin has a chlorine content of 1 to 50 wt .-%, preferably 2.5 to 40 wt .-%, based on the polyolefin, preferably one weight average molecular weight of 10,000 to 100,000 daltons, preferably 15,000 to 60,000 daltons (gel permeation chromatography determined using a polypropylene standard) and preferred a non-uniformity U = Mw / Mn-1 between 1.0 and 6.5, preferably between 1.5 and 4.5.

The introduction Chlorine is carried out in a conventional manner by chlorination of as starting material serving amorphous polyolefins (see this for example, Houben-Weyl, Methods of Organic Chemistry, Vol V / 3, pages 511 to 551, Georg Thieme Verlag, Stuttgart, 1962). For the preparation of the components (B) according to the invention, the Chlorination at temperatures between about - 10 degrees C and the boiling point of the solvent used in each case performed.

to Preparation of the water-dilutable invention Binders are 20 to 90 wt .-%, preferably 55 to 85 wt .-% the mixture (A) in the presence of 9.9 to 79.9 wt .-%, preferably 15 to 45 wt .-% of component (B) and 0.1 to 10 wt .-%, preferably 1 to 7 wt .-% of component (C) radically polymerized, and the obtained polymerization product is after neutralization of at least 20% of the carboxyl groups contained in the polymerization in Water dispersed. The sum of the weight percentages for the components (A), (B) and (C) always gives 100 wt .-%. As component (C) can in principle all known radical formers are used. They are preferably such free-radical initiators used at the polymerization temperature a Half-life, which is between 15 and 180 minutes. As examples of usable radical formers are called: dialkyl peroxides, such as e.g. Dicumyl peroxide and di-tert-butyl peroxide, peroxyesters, such as e.g. tert-butyl peroxybenzoate, tert-butyl peroxyoctanoate, tert-butyl peroxyacetate and tert-butyl peroxyisobutyrate, diacyl peroxides, e.g. benzoyl peroxide and acetyl peroxide and azo compounds, such as e.g. Azobis (isobutyronitrile).

The Polymerization of the mixture (A) in the presence of the components (B) and (C) may be in bulk, in aqueous emulsion or in an organic solvent or a mixture of organic solvents. The polymerization is preferably in an organic solvent or a mixture of organic solvents, in particular in nonpolar solvents with a boiling range between 120 to 200 degrees C, preferably 135 to 190 degrees C at polymerization temperatures of 120 to 200 Grade C, preferably 130 to 160 degrees C.

to Neutralization of the polymerization product is preferred organic amines, in particular tertiary amines, such as dimethylethanolamine used.

The aqueous varnishes and their use

Using the binders according to the invention, aqueous paints can be prepared by methods well known to those skilled in the art those used for the primer or single-coat paint of plastics, especially plastics based on polypropylene or copolymers of propylene and copolymerizable monomers, such as. As ethylene, are used and with which lacquer layers can be produced, which adhere very well to pretreated and untreated plastic substrates. The binders according to the invention can also be used in basecoats for the production of multilayer coatings of the "basecoat-clearcoat" type.

The produced using the binders of the invention aqueous paints can in addition to the binders according to the invention also even more compatible Synthetic resins, e.g. Polyacrylate resins, polyester resins and polyurethane resins (See, for example, DE-A-42 39 695) and crosslinking agents such as. As aminoplast resins and / or optionally blocked polyisocyanates contain. When using unblocked polyisocyanates it is usually appropriate, the aqueous paints store as a two-component system.

The produced using the binders of the invention aqueous paints can formulated both without and with pigments or fillers. You can also in very thin Layer thicknesses (for example, 5 to 10 microns) are applied.

The produced using the binders of the invention aqueous paints usually contain 30 to 80 in the ready-to-use state Wt .-%, preferably 45 to 70 wt .-% water, 0 to 50 wt .-%, preferably 0 to 10% by weight of organic solvents, From 6 to 70% by weight, preferably from 15 to 45% by weight, of the binder according to the invention, 0 to 40 wt .-%, preferably 0 to 25 wt .-% pigments and / or fillers and 0 to 10% by weight of other additives, such as catalysts, thickeners, leveling agents, etc., the weight percentages are based on the total formulation of the paints in the ready-to-use state (that is to say, for example, in the case of spray viscosity) are.

With produced using the binders of the invention aqueous paints can be plastics such as ABS, AMMA, ASA, CA, CAB, EP, UF, CF, MF, MPF, PF, PAN, PA, PC, PE, HDPE, LDPE, PETP, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PP-EPDM and UP (abbreviated to DIN 7728T1), preferably Polyolefins such as polypropylene and polypropylene EPDM primed or be painted one layer. Of course, the plastics to be painted can also be used Polymer blends, modified plastics or fiber reinforced plastics be. The with the aqueous Lakken according to this Invention primed plastics can be easily, e.g. with single-layered Single or metallic effect finishes or with two-layer or metallic basecoat Clearcoat-type paint finishes become.

following The invention will be explained in more detail with reference to embodiments. there all parts mean parts by weight, unless expressly something is specified otherwise.

Examples

1. Preparation of an aqueous dispersion a binder according to the invention

1000 parts of a chlorinated polyolefin (Trapylen ^® 822 X from Tramaco, 20% solution in xylene) having a chlorine content of 24.5 wt .-% are weighed in a stainless steel polymerization vessel with stirrer, reflux condenser, a monomer feed and an initiator feed and heated to 130 degrees C. The mixture is stirred for 1 hour at this temperature.

Then a mixture of 48 parts of di-tert-butyl peroxide and 137 parts of SHELLSOL ^® A within 5 hours at a constant rate is added dropwise to the homogeneous mixture as the temperature is maintained in the reaction mixture at 130 ° C.

30 Minutes after the beginning of the addition of the di-tert-butyl peroxide solution, a mixture of 214 Butyl methacrylate, 216 parts methyl methacrylate, 248 parts Cyclohexyl methacrylate and 122 parts of methacrylic acid within 4 hours added.

To Termination of the Initiatorzulaufs is postpolymerized for a further 2 hours. The reaction mixture is then treated with butyl acetate 98/100 on a non-volatile content Diluted components of 45 wt .-% and cooled to 110 degrees C.

These solution will follow with 114 parts of dimethylethanolamine and for 30 minutes touched. Subsequently 2713 parts of deionized water are added with stirring at 80 degrees C.

Out the thus obtained aqueous Dispersion will eventually the organic solvents distilled off until a residual solvent content of less than 5 % By weight has been achieved.

The resulting aqueous Dispersion has a non-volatile content of 30% by weight (1 hour / 130 degrees C), an acid number of 80 and a pH of 8.3.

2. Using the after Example 1 prepared aqueous dispersion for priming substrates

The prepared according to Example 1 aqueous binder dispersion is diluted with deionized water to a viscosity of 25 sec (DINO cup) and wiped at 23 degrees C and 60% relative humidity with an injection pressure of 4 to 5 bar on previously soaked with isopropanol paper towel test panels made of polypropylene (Keltan ^® TP 0550 of Fa. DSM) applied so that a dry film thickness of 5 microns results. During application, no sedimentation problems or sagging occurred. The film is flashed off for 10 min at 23 degrees C. Subsequently, a solvent-based metallic basecoat under the above conditions with a dry film thickness of 15 microns is applied. After a flash-off time of 5 min at 23 ° C., a solvent-containing two-component clearcoat is applied under the abovementioned conditions with a dry film layer thickness of 40 μm. After a 15 minute bake at 23 degrees C, the entire paint is baked at 120 degrees C oven temperature for 45 minutes. The paint thus prepared adheres very well to the substrates.

Claims (11)

Water-dilutable binders for the preparation of thixotropic aqueous paints, characterized in that the rheology control agent is prepared by (A) 20 to 90 wt .-% of a mixture of (a1) 3 to 50 wt .-% acrylic acid, methacrylic acid or a mixture of acrylic acid and (a2) 50 to 97% by weight of an ethylenically unsaturated monomer other than (a1) or a mixture of such ethylenically unsaturated monomers in the presence of (B) 9.9 to 79.9% by weight of a Chlorine-containing polyolefins having a chlorine content of 1 to 50 wt .-%, based on the polyolefin, and C) 0.1 to 10 wt .-% of a radical generator or a mixture of free radical initiators are polymerized and the resulting polymerization after neutralization of at least 20 % of the carboxyl groups contained in the polymerization is dispersed in water, the sum of the weight percentages for the components (A), (B) and (C) and (a1 ) and (a2) in each case always gives 100% by weight and the composition of the mixture of (a1) and (a2) is selected such that upon polymerization alone of the mixture of (a1) and (a2) a polymer is obtained, which has a glass transition temperature of 0 to 150 degrees C, contains 0.04 to 1.0 milliequivalents of one or more of the following functional groups: -COOH, -OH, -NR ₃ , -CN, -CONH ₂ , -CO- , -NHCONH-, -OCONH-, -OPO ₃ H, -OSO ₃ H, -ROR- (where R is an organic radical) and - that to 0 to 50 wt.% Of one or more of the following cycloaliphatic groups, which may be substituted by at least one alkyl group containing from 1 to 12 carbon atoms, consists of: cyclopentyl, cyclohexyl, perhydronaphthyl, perhydroanthracyl, perhydrophenanthryl, adamantyl, isobornyl, bicyclohexyl, bicycloheptyl, bicyclooctyl , Bicyclononyl, bicyclodecyl, bicycloundecyl and bicyclododecyl group. dilutable Binder according to claim 1, characterized in that the component (A) is used in an amount of 55 to 85 wt .-%. dilutable Binder according to claim 1 or 2, characterized in that the component (a1) is used in an amount of 5 to 20 wt .-%. dilutable Binder according to one of the claims 1 to 3, characterized in that the component (B) in a Amount of 15 to 45 wt .-%, based on the total amount of the components (A), (B) and (C) is used. dilutable Binder according to one of the claims 1 to 4, characterized in that the component (C) in a Amount of 1 to 7 wt .-%, based on the total amount of the components (A), (B) and (C) is used. dilutable Binder according to one of the claims 1 to 5, characterized in that the chlorine-containing polyolefin (B) a chlorine content of 2.5 to 40 wt .-%, based on the polyolefin (B), and / or that the chlorine-containing polyolefin (B) a weight-average molecular weight Mw of 10,000 to 100,000 daltons and / or that the chlorine-containing Polyolefin (B) has a nonuniformity U between 1.0 and 6.5. dilutable Binder according to claim 6, characterized in that the chlorine-containing Polyolefin (B) has a weight-average molecular weight Mw of 15,000 has up to 60,000 daltons and / or that the chlorine-containing polyolefin (B) has a nonuniformity U between 1.5 and 4.5. Water-dilutable binders according to one of claims 1 to 7, characterized in that the composition of the mixture of (a1) and (a2) is selected so that upon polymerization of the mixture of (a1) and (a2) alone, a polymer is obtained which - has a glass transition temperature of 10 to 80 degrees C, - contains 0.1 to 0.5 milliequivalents of one or more of the following functional groups: -COOH, -CN, -CNH ₂ and -ROR- and - to 5 to 25 wt % consists of cyclohexene groups or isobornyl groups or a mixture of these groups. Use of a water-dilutable binder after a the claims 1 to 8 for the preparation of an aqueous Paint. Use of an aqueous lacquer according to claim 9 for priming or single-layer coating of substrates made of plastic. Use according to claim 10, characterized the plastic substrate is polypropylene.