DE2752198A1 - Aq. lacquer compsn. contg. organic titanium cpd. - pref. partly reacted with binder used for cathodic electro-immersion and other coating processes - Google Patents

Abstract

Aq. lacquer compsn. contains >=1 organic Ti cpd. in addn to cationic lacquer binder and opt. pigment and standard lacquer additives. Ti content is 0.1-15 wt. % w.r.t. lacquer binder. Used for (i) cathodic electro-immersion lacquering of electrical conductors and (ii) coating by spraying, dipping, spreading, rolling, brushing or electrostatic spraying. Organic Ti cpd. treatment or addn. improves hardened lacquer protection against corrosion, and also hardness, adhesion, elasticity and resistance to water. Improved temps. are achieved at stoving temps. which are up to 20% lower. The aq. compsns. are highly stable.

Description

OZ 32 902 Aqueous paint preparation 2 / b2l98

The invention relates to aqueous paint preparations which contain cationic paint binders dissolved or dispersed in water.

Cationic lacquer binders, which can be produced by polymerization, polyaddition or polycondensation, their cationic character obtained by neutralization or partial neutralization of built-in amine, ammonium, phosphonium or sulfonium groups and are thereby simultaneously soluble or dispersible in water, are known and are described, for example, in DT -AS 1 276 260, DT-OS 2 Ml9 179, DT-OS 2 55 ¹ »080, DT-OS 2 252 530, PR-PS 1 313 355 and others

These lacquer binders can be processed using customary application methods, but preferably by the method the cathodic electrodeposition coating. The electrically conductive substrate to be coated is used as the cathode a direct current circuit that runs through the cationic paint binder containing electrodeposition bath is formed with the anode, provided with a coating.

Cathodically deposited lacquer coatings have a number of advantages on. The aim of the present invention is to provide the lacquer coatings obtained with lacquer preparations based on cationic binders, in particular to improve their corrosion protection and their water and chemical resistance.

Surprisingly, this was achieved by adding organic titanium compounds.

The present invention relates to an aqueous paint preparation Containing a cationic lacquer binder and optionally pigment and other additives customary in lacquer technology, which is characterized in that it contains at least one organic titanium compound, with the proviso that the titanium content 0.1 to 15 weight?, Based on the paint binder.

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Preference is given to aqueous paint preparations whose paint binder has been at least partially reacted with the organic titanium compound.

The present invention also relates to the use of these aqueous lacquer preparations for cathodic Electrocoating of electrically conductive substrates as well as for the production of coatings by spraying, dipping »painting, Rolling, squeegeeing or electrostatic spraying.

The paint preparations according to the invention are advantageous to process; the coatings produced with it have improved Water and chemical resistance as well as improved corrosion protection.

The following is to be said about the individual components that make up the paint preparations according to the invention:

The water content of the paint preparations according to the invention is oriented depends on the application method to be used and can vary between 95 and 30 percent by weight.

Suitable cationic lacquer binders are self-crosslinking or externally crosslinking binders, such as are obtained in the usual way by polymerization, polyaddition or polycondensation, the at least partially with water-soluble acids, preferably carboxylic acids, neutralized basic groups, such as amine, Contain built-in ammonium, sulfonium or phosphonium groups.

Cationic water-dispersible paint binders, the production of which is not the subject of the present invention, come E.g. those in the above DT-OS and PR-PS in question as well as:

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Copolymers of aminoalkyl ester salts of (meth) acrylic acid, as for example in DT-PS 1 546 840; NL-PS 70 17 172, DT-OS 20 02 756; DT-OS 23 25 177; U.S. Patent 3,883,483 and U.S. Patent 3,853,803;

Copolymers of salts of vinylated nitrogen-based heterocycles, such as those of DT-PS 1 276 260 and the See U.S. Patent 3,853,803;

Copolymers of salts of polymerizable aminoalkylamides (see e.g. DT-AS 1 5 ^ 6 848);

Salts of epoxy resins bearing basic groups, as for example in BE-PS 693 753; DT-AS 18 14 072; U.S. Patent 3,640,926; DT-OS 19 30 949; FR-PS 2,051,662; GB-PS 1,235,975; U.S. Patent 3,719,626; DT-OS 20 33 770; DT-OS 20 03 123; DT-OS 21 63 143; DT-AS 22 37 114 and U.S. Patent No. 3,925,180;

Salts of Mannich bases based on phenols, such as those found in DT-AS 16 44 839 and GB-PS 1 302 328 are;

Reaction products of Mannich bases with epoxy resins, as described in DT-OS 23 20 301, 23 57 075, 25 41 801 and 25 54 08O are;

solubilized polyamides (see e.g. GB-PS 1 302 328);

Polymers with quaternary ammonium groups, as described, for example, in DT-OS 23 39 398, DT-OS 21 63 143 and DT-OS 22 37 114;

Polymers with sulfonium groups, such as in the DT patent applications P 25 57 562 and P 25 48 394, the NL-PS 7 205 85I ;. U.S. Patent 2,166,214; DT-OS 2261804; U.S. Patent 3,873,488; U.S. Patent 3,793,278; GB-PS 1,370,966;

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Polymers with phosphonium groups (see e.g. DT-OS 22 6l 804) as well as Urethane polymers with ammonium groups, such as those from the Japanese Patent applications 8IOI-M3O and 8101-431 and U.S. Patent 3,891,527 are known.

The cationic water-dispersible resins are (co-) crosslinkable when heated. The networking takes place via reaction-capable Groups that are built into the resin molecule, e.g. hydroxyl, amide, N-methylolamide, N-methylolamide ether, ester, -amides, epoxy groups, blocked isocyanate groups or reactive double bonds.

Instead of a specific cationic resin, there are also mixtures of cationic resins, for example a resin with quaternary ones Ammonium groups and a resin with ternary sulfonium groups can be used.

The cationic lacquer binder can also be combined with other reactive or neutral binders, such as amino resins, phenolic resins, blocked polyisocyanates or hydrocarbon oils are blended, which in many cases produces special effects can be.

Suitable organic titanium compounds are those of the general types Formulas

Ti (OR) ₁₁ , Ti (OCOR) _11-0 (OR) _n and

polymeric compounds derived from these and having the general formulas

Location

TiO OR

OCOR Ti-O

η = 1 - 3 χ = 2 - 50

R denotes an alkyl radical with 1 to 20 carbon atoms, a cycloalkyl radical with 5 to 20 carbon atoms or an aryl radical, where

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these residues can also be modified in such a way that they lead to formation of chelate complexes. Common chelate complexes of these Type are e.g. isopropyltriethanolamine titanate, isopropyl acetylacetone titanate, Isopropyl octyl glycol titanate and tetraoctylene glycol titanate.

The paint preparations according to the invention contain the organic titanium compounds in such amounts that the titanium content is related on paint binder, 0.1 to 15, preferably 1 to 10, percent by weight.

A preferred embodiment of the present invention is in that the lacquer binders are reacted with the organic titanium compounds before the lacquer dispersion is prepared or the titanium compounds are linked to this during the manufacture of the paint binder.

The aqueous coating preparations obtainable therefrom are distinguished by a particularly high stability.

It is of course also possible to initially only use part of the paint binder with a higher proportion of organic To implement titanium compound and this then with titanium-free paint binder to combine.

The processing of the reaction products into aqueous paints, in particular to electrodeposition paints takes place in the customary and known manner.

The aqueous paints may contain pigments, e.g. titanium dioxide, Iron oxide, talc, carbon black and other additives customary in paint technology, such as solvents, preferably water-thinnable Solvents, protective colloids, emulsifiers, stabilizers and other auxiliaries.

In addition, organic titanium compounds which are water-soluble or organic titanium compounds which have been made water-distributable by suitable measures can already be used water-dispersed binders are added, provided that the

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Peculiarity of the binder in this case to stable dispersions leads, i.e. the binder with the organic titanium compounds or the hydrolysates of these compounds while maintaining the aqueous dispersion reacts or the water-insoluble organic titanium compounds, etc. whose hydrolysates are absorbed by the binders in the aqueous dispersion and so on do not disturb the stability of these dispersions.

Suitable water-soluble titanium compounds are titanium chelate complexes, for example isopropyltriethanolamine titanate, isopropyldihexylglycotitanate, or titanium chelate complexes as they are used in the reaction of alkyl titanates with other compounds capable of chelating are formed, in particular when alkyl titanates are reacted with Mannich bases and polymeric Mannich bases.

Suitable measures to avoid organic titanium compounds, e.g. of the type To make the alkyl titanates dispersible in water, the adsorption on finely divided amorphous silicon dioxide, or her Enclosure in small capsules, the walls of which are destroyed when the films cure.

From the aqueous paints are in a known manner, preferably by the process of cathodic electrodeposition on Metals, preferably iron and steel and phosphated iron and steel, lacquers are applied and hardened by the action of heat to form lacquer coatings whose corrosion protection, hardness, adhesion, elasticity and water resistance are better than if the same Resin bodies without organic titanium compounds can be used for paint preparation.

Another advantage of the invention relates to the stoving temperature necessary for curing the lacquer coatings. Depending on the nature of the starting binder, at stoving temperatures which are up to approx. 20 % lower, the properties that can be achieved with the resin base bodies used without the addition of titanium are achieved or exceeded.

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The lacquer preparations according to the invention can also be carried out according to conventional Application methods are processed, namely by spraying, dipping, brushing, rolling, squeegeeing or electrostatic Spray and must be adjusted to the process-typical processing viscosity.

The following examples are intended to explain the invention without restricting it.

The parts and percentages given in the examples are based on weight, unless stated otherwise.

Comparative example A.

According to DT-OS 2 554 080, Example 2, a resinous Mannich condensation product is produced. The stoving residue is adjusted to 70%. It is referred to as binder M in the following.

100 parts of binder M
145 parts of titanium dioxide pigment
50 parts of talc

5 parts of carbon black
200 parts of isodecanol
200 parts isopropanol

are mixed and in a ball mill to a grain size 7 / U ground. This milling batch is referred to as paste P in the following

142 parts of binder M
70 parts paste P
1.8 parts acetic acid

are mixed and with vigorous stirring with water to 1000 parts diluted. The lacquer bath obtained is referred to below as L A.

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example 1

The procedure is as in Comparative Example A, but that for production The amount of binder M required for the paint bath is first mixed with 2 parts of tetraisopropyl titanate under dry nitrogen

Brought to reaction for 2 hours at 50 °. The lacquer bath produced therefrom is referred to below with L 1.

Example 2

The procedure is as in Example 1, but instead of tetraisopropylt itanate is 5 parts of isopropyltriethanolamine titanate used. The paint bath is referred to below with L 2.

Example 3

The procedure is as in Example 1, but instead of tetraisopropylt itanate, 7 parts of tetra (2-ethylhexanediol-1,3) titanate are used. The lacquer bath obtained is denoted below with L 3 designated.

The lacquer baths LA to L 3 are stirred for 24 hours at room temperature and then used for the cathodic electrodew coating of iron-phosphated sheet steel. (Pesticide content: 12.7 %, pH: 7.5, temperature: 23 ° C, voltage: 180 V).

The paint deposits are 20 minutes at 170 ° and further deposits Hardened for 20 minutes at 180 °. The quality of the coatings is shown in the table.

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Lacquer bath No. LA Ll L2 L 3

(Comparison)

Baking temperature (° C) l80 ° 170 ° 180 ° 170 ° l80 ° 170 ⁰ l80 ° 170 ⁰

Erichsen depression 4.5 3.2 4.8 5.9 5.0 6.9 5.2 7.3 (according to DIN 53156)

Pendulum hardness I58 "130" 174 "158" 172 "146" I67 "l4l" (according to DIN 53157)

Salt spray test ** 8 12 4 8 3 7.5 2.5 6

mm Infiltration at the cut after 240 hours of exposure according to DIN 50021

Comparative example B

The paint preparation is produced as described in Comparative Example A, but only diluted to 350 parts. The resulting paint has a solids content of 35.4 % and a viscosity of 32 seconds in a DIN 4 cup (DIN 53 211).

Example 4

The paint preparation is produced as described in Example 2, but only diluted to 350 parts. The resulting paint has a solids content of 36.2 % and a viscosity of 37 seconds in the DIN 4 cup (DIN 53 211).

The water-based paints according to Comparative Example B and Example 4 are degreased in three cross passes with a spray gun Sprayed on steel sheets, stored for 20 minutes at room temperature and then baked for 20 minutes at 180 ° C. The paint films are scratched to the sheet metal and 96 hours of SaI spray treatment exposed to ASTM. The coatings according to Comparative Example B are now infiltrated up to a width of 9 at the cut, the Paintwork according to example 4 only 4 mm.

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BASF Aktiengesellschaft

Claims (4)

BASF Aktiengebell-ächaft Our reference: OyZ. 32 902 Ls / BL 6700 Ludwigshafen, 11/21/1977 claims 1. Aqueous paint preparation containing a cationic paint binder and optionally pigment and other additives customary in paint technology, characterized in that it contains at least one organic titanium compound, with the proviso that the titanium content is 0.1 to 15 percent by weight, based on the paint binder. 2. Aqueous paint preparation according to claim 1, characterized in that the paint binder has been at least partially reacted with the organic titanium compound. 3. Use of the aqueous paint preparation according to claim 1 or 2 for cathodic electrodeposition painting conductive substrates. 4. Use of the aqueous paint preparation according to Claim 1 or 2 for the production of coatings by spraying, dipping, brushing, rolling, knife coating or electrostatic means Spraying. 909823/0033 -2- ORIGtNAL INSPECTED