NL8301560A - METHOD FOR PREPARING AIR-DRYING BINDER EMULSIONS - Google Patents

Description

*, '2, ♦ VO 4759 * —1—

Process for preparing air-drying binder emulsions »

The invention relates to a process for the preparation of air-drying binder emulsions based on urethane-modified alkyd resins and urethane oils, wherein as emulsifying component with polyethylene glycol (PEG) modified vinylated and / or acylated fatty acid esters are used.

There are a number of patents which describe acrylic-modified alkyd resins as a binder for water-dilutable air-drying lacquers (including U.S. Patent 4,133,786 and British Patent 1,117,126). Likewise, a use of water-dilutable urethane oils or urethane-modified alkyd resins for air-drying lacquers is known (see, inter alia, European 0.017.199, European 0.018.665, DE-OS 17.45.343, DE-PS 23.23.546, CJS-PS 4,017,514 and DS-PS 4,116,902).

However, both binder groups have specific drawbacks.

Owing to the reactivity of the unsaturated fatty acids reduced by the copolymerization, the acrylic-modified alkyd resins show only a moderate cross-linking and therefore a poor resistance of the lacquer films. Furthermore, they require a high content of volatile toxic amines to neutralize the acid groups. The urethane oils and urethane-modified alkyd resins, due to poor pigment wetting, cause poor compatibility with adhesives and major problems in the preparation of lacquers. Moreover, it also applies to them that large amounts of amines are required to stabilize the emulsions.

Also known is the combination of urethane oils or urethane-modified alkyd resins in emulsified form with polyvinyl or polyacrylic latices, respectively (US Patent 3,919,145). However, due to the inert, non-crosslinkable latex content of these binder emulsions, only a moderate film quality can be obtained, so that these products are only used for so-called "House Paints".

It has now been found that air-drying aqueous emulsions of urethane-modified alkyd resins and / or urethane oils are obtained when the emulsifying component used is PEG-containing polyol esters of unsaturated fatty acids, these polyol esters being specifically modified by graft copolymerization .

8301560 -2- Μ ί ϊ

The present invention therefore relates to a process for preparing air-drying aqueous emulsions of urethane-modified alkyd resins and / or urethane oils, which can be used as a binder for unpigmented or pigmented lacquers and paints, which method is characterized in that (I) 25-50% by weight of an emulsifier component water-soluble after neutralization with inorganic or organic bases, which has an acid number of 25 - 70 mg KOH / g, a hydroxyl number of up to 40 mg 10 KOH / g g, shows a polyethylene glycol content of 7 to 13% by weight and a limit viscosity number of 9 to 15 ml / g (determined in chloroform at 20 ° C) 'and which by graft copolymerization from (a) 50 - 75% by weight of an acid number polyethylene glycol-containing polyester of fatty acids showing less than 5 mg KOH / g, having an average iodine value of 140 or more with (b) 17-45 wt.% of vinyl and / or acrylic and / or methacrylic monomers, that be half of the double bond show no further functional group and (c) 5-8 wt.% of α, β-olefinically unsaturated carboxylic acids are obtained, and (II) 50 - 75 wt.% of an air-drying urethane modified alkyd resin and / or a urethane oil containing tertiary amino groups bound according to an amine number of 3-25, preferably 5-15 mg KOH / g, and a limit viscosity number 25 between 8 and 20 ml / g (determined in chloroform at 20 ° C), homogeneously mixed at 50-100 ° C and after partial neutralization of the carboxyl groups with an organic and / or inorganic base in an amount corresponding to an acid number of up to 15 mg KOH / g and in the presence of up to 20% by weight of an organic solvent with water which emulsifies in water.

The emulsions prepared according to the invention contain only a very low content of volatile amines, preferably less than 1%, and are very stable. They exhibit excellent pigment wetting and can therefore be easily processed into highly glossy coatings or highly pigmented primers. They exhibit good flow and excellent through-drying, and have only a slight tendency to surface distortions, such as crater or edging.

flee and give films of good resistance.

It is known that urethane-modified binders with other binders usually tolerate very poorly. Therefore, it could not be foreseen that an addition of the positive properties of the components can be achieved with such combinations, even when these cost-effective emulsifier components are used. Surprisingly, the alkyd resin emulsions prepared according to the invention also exhibit particularly good compatibility with polymer dispersions.

The emulsifier component (I) used according to the invention consists according to the invention of a PEG-containing polyester of fatty acids, which on average have an iodine number of 140 or more and by graft copolymerization with α, S-olefinically unsaturated monomers, which also proportionally carry carboxyl groups , have been modified.

The PEG-containing polyol ester (a) is converted by converting equivalent amounts of unsaturated fatty acids. preference of conjugated fatty acids and a polyethylene glycol (PEG) with an average molecular weight between 1000 and 3000 in the presence of a naturally or synthetically prepared polyol ester of fatty acids, which on average exhibit an iodine value of at least 140 and predominantly isolated double bonds o 20, at 240 - 260 ° C. These esters exhibit an acid number of less than 5 mg KOH / g, preferably less than 2 mg KOH / g.

Particularly suitable fatty acids for the reaction with the PEG are the products derived from the dehydrated castor oil and, if appropriate, aftertreated, conjugated fatty acids, as well as products obtained from other oil fatty acids by isomerization. However, selected fatty acids with isolated double bonds are also applicable, in particular linseed oil fatty acids.

To obtain optimal results, the PEG or optional mixture of various polyethylene-30 glycols used should have an average molecular weight of about 1500 + 200.

As polyol esters, on the one hand, the natural drying oils, for example linseed oil, safflower oil or mixtures of these oils with up to 15% by weight of a dehydrated castor oil, on the other hand, synthetic esters of the fatty acid mixtures with polyols present in these oils, such as pentaerythritol or trimethylolpropane or the corresponding esters of tall oil fatty acids. In the fatty acids present in these polyesters, the double bonds must be present for at least 75% as isolated double bonds. Mixed with the polyol esters, unsaturated hydrocarbon oils, such as low molecular weight butadiene polymers, at levels of up to 30% by weight, may also be used. The hydroxy number of the PEG-containing ester (a) should not exceed 50 mg ROH / g. If fatty acids are used exclusively, the preparation of this component can also be effected by simultaneously reacting all the fatty acids with the PEG and the polyol.

As monomers (b) which participate in the build-up of the emulsifier component (I) in an amount of 17 - 45% by weight, vinyl and / or acrylic and / or methacrylic compounds are used, which have no functional group except the double bond exhibit. Their choice is mainly directed to the desired properties which the lacquer films obtained from the emulsion must exhibit.

For the universally applicable emulsions, which also allow the formulation of coatings, the following composition is preferably indicated: 60 - 78 wt.% Monomers, which are gasoline-soluble polymers with a glass transition temperature (Tg) above 70 ° C. forms, especially vinyl toluene; 22-40% by weight of monomers exhibiting in gasoline-soluble polymers with a glass transition temperature below 70 ° C (preferably 20 -60 ° C), especially n-butyl and isobutyl methacrylate.

As a, β-olefinically unsaturated carboxylic acid (c) is preferably and also. mixed until at least 50 mol% acrylic acid is used. In addition, methacrylic acid and particularly advantageous (with respect to pigment wetting) male esters of maleic acid with monoalcohols having 3-8 carbon atoms, in particular isopropyl maleinate, can be used.

Low levels of maleic half esters can also be introduced by addition of maleic anhydride to the unsaturated fatty acids of component (a) and reaction of the arfydride structure with the corresponding monoalcohols.

Graft copolymerization advantageously takes place by slowly adding the mixture of the monomers with about 20% by weight of 8301560 * -5- component (a) and (from a separate addition vessel) a peroxide to the remaining about 80% of the component (a) at temperatures in the vicinity of 130 ° C. The mixture is then further maintained at 130-145 ° C until an almost complete reaction of the monomers has taken place and the desired limit viscosity number has been reached. Monomer residues as well as any solvents used are filtered off in vacuo and, if necessary, the mixture is diluted with about 10% of a water-bearing solvent, for example a glycol ether.

Suitable initiators for graft copolymerization are peroxides, such as di-tert-butyl peroxide, tert-butyl perbenzoate, cumohydroperoxide or diol peroxide.

The urethane-modified alkyd resins and / or urethane oils, which are used as component (II) in the emulsions according to the invention, are water-insoluble resins which are mainly dissolved from the known products in organic solvents and used as lacquer binder. distinguish a content of bound tertiary amino groups. They are by weight the main component of the solid resin content of the emulsions of the invention and therefore have a decisive influence on film formation and film properties. Thus, in its formulation, the main objective is placed on rapid drying and good oxidative film cross-linking. The amino groups have the task of promoting compatibility with the acidic emulsifier resins. They thereby increase the combination leeway and improve emulsion stability and film quality. In addition, the salt-like bonds with the carboxyl groups also contribute to the retardation with water, so that the content of volatile amines which pollute the environment during application can be reduced accordingly. Surprisingly, the water resistance of the lacquer films is not adversely affected, provided that the amine number does not exceed the value of 25 mg KOH / g.

The urethane-modified alkyd resins or urethane oils preferably used for the emulsions according to the present invention are characterized by the following characteristics: content of unsaturated oil fatty acids 45 - 70%, content of aromatic or cycloaliphatic monocarboxylic acids 0 - 20% 8301560 <-6-.

; i content of polyalcohols 15 - 25% content of dicarboxylic acids 0 - 16% content of diisocyanates 8 - 25% amine number 3-25 (preferably 5-15) mg KOH / g 5 acid number below 5 mg KQH / g hydroxyl number 0 - 80 mg KOH / g limit viscosity number [^] 8 - 16 ml / g (chloroform, 20 ° C)

The stated number ranges are critical insofar as they concern the amine number and the limit viscosity number for the emulsions of the present invention. The other parameters indicated are indicated in their preferred ranges and can also be varied within wider limits.

As unsaturated fatty acids, those with isolated and conjugated double bonds with an iodine value greater than 125 are suitable. Examples are: soy, safflower, linseed or tall oil fatty acids and the fatty acids of wood oil. The fatty acids can be used free or in the form of their glyceride oils or synthetically prepared polyol esters. The choice of the aromatic or cycloaliphatic monocarboxylic acids, of the polyalcohols and the dicarboxylic acids is not critical and can be made by the skilled person on the basis of the desired properties and key figures.

In view of the drying speed and film hardness, especially diisocyanates are aromatic products, such as 4,4'-diphenylmethane diisocyanate and tolylene diisocyanate. The technical mixture of 80% 2.4 and 20% 2,6-tolylene diisocyanate is preferably used.

To introduce the tertiary amino groups, amines of the general formula R @ 2 are used

Y - R. - N

1 X

R3 is used, wherein Y represents a hydroxyl or a primary or secondary amino group, R represents an alkylene radical with 2-5 C atoms and R3 as well as R8 represents an alkyl radical with 1-4 C atoms. The amount of the amine is chosen such that after the reaction with the diisocyanates 35 an amine number of between 3 and 25, preferably between 5 and 15 mg, KOH / g results.

The preparation of the urethane-modified binders 8301560 I-7- takes place in two steps: first, a low-molecular weight, hydroxyl-rich alkyd resin with an acid number below 5 mg KDH / g or a fatty acid polyol partial ester prepared »Then an inert solvent is added and the diisocyanate is added at 40 DEG-60 DEG. The mixture is kept at 60-80 ° C until the content of free NCO groups has fallen to about half of the theoretical baseline. The amine is then diluted with slightly inert solvent, added and the temperature raised to 90-110 ° C. This temperature is maintained until the NCO content has fallen below 0.1% and the desired limit viscosity number has been reached.

According to a special embodiment of the invention, the components (I) and (II) for the emulsification are subjected to a post-treatment, whereby both the drying speed, in particular the surface drying (tack-free), as well as the cold resistance of the emulsions is still being improved.

This post-treatment consists in that for the emulsification in water, the component (I) is treated with air at 80-160 ° C, preferably 100-150 ° C, for as long as possible to a peroxide number of at least 20 milli-20 equivalents per kg and an increase of the limit viscosity number (CHCl 2, 20 ° C) with at least 1 ml / g and / or the mixture of components (I) and (II) with 1.5 - 10 mmol / 100 g of the resin mixture of an aromatic and / or aliphatic diisocyanate in the presence of an inert solvent and, optionally, removing the solvent from the reaction mixture prior to neutralization and emulsification by distillation.

Both measures can be applied individually, but can also be applied one after the other. By blowing with air at 80-160 ° C, on the one hand, an improvement in the drying speed (in particular the top-30-roof drying) is obtained, which can be traced back to the formation of hydroperoxide groups; on the other hand, this measure also improves the compatibility, in particular with short-oil and high-molecular resins of the component (II), as well as, to a certain extent, the cold resistance of the aqueous emulsions.

The reaction of the mixture of components (I) and (II) with 1.5 - 10 mmol (per 100 g of the mixture) of an aromatic and / or aliphatic diisocyanate gives an essential ___— 8301560 1 * by molecular cross-linking. -8- improving the cold stability of the emulsions. This modification is, of course, only possible if the components exhibit a minimal number of hydroxyl groups, which either originate from the resin formulation or which may have been secondary by blowing with air.

Preferably, this modification is applied to products with a hydroxyl number of about 20 or more.

By cold resistance of the emulsion it is understood that the properties of the emulsion practically do not change even after cooling several times below the freezing point of the water and heating again at room temperature. While the emulsions without post-treatment have a cooling at -5 ° C without any influence, the after-treated emulsions according to the methods described here can be cooled to -20 ° C without adverse effects and reheated.

The blowing with air takes place after the end of the graft copolymerization as well as the removal of any solvent present or the rest of the monomers at 80 - 160 ° C, preferably at 100 - 150 ° C. Blowing (or sucking through) air the reaction mass is continued until the peroxide number (determined by Wheeler) is at least 20 milliequivalents kg-20 and the limit viscosity number, determined in chloroform at 20 ° C, has increased by at least 1 ml / g. In view of the amounts of a commercially available sulfur, for example 0.02% of a 5% Co-sulfative solution, it can also be used to accelerate the measure.

When using the after-treatment method, as component (II), urethane-modified alkyd resins or urethane oils can also be used, which have expanded limit values: content of unsaturated oil fatty acids 35 - 70% content of aromatic or cycloaliphatic monocarboxylic acids 0 - 25% 30 content of polyalcohols 15 - 30% content of dicarboxylic acids 0 - 20% content of diisocyanates 8 - 25% amine number 3-25 (preferably 5-15) mg KOH / g acid number below 5 mg KOH / g 35 hydroxyl number 0-100 mg KOH / g limit viscosity number [ ^] 8-20 ml / g, (chloroform, 20 ° C) 8301560-«-9-

Also in this case, the indicated number ranges are critical insofar as they relate to the amine number and the limit viscosity number for the emulsion of the present invention. The other parameters mentioned are indicated in their preferred ranges and may also be varied within further limits.

To obtain emulsions with optimum cold resistance, the emulsification components can be partially cross-linked with an aromatic or aliphatic diisocyanate. Toluylene diisocyanate is preferably used, the amount being chosen such that on the one hand the desired effect is achieved, on the other hand other properties such as the pigment wetting are not negatively influenced. Usually 1.5-10 mmol diisocyanate per 100 g resin can be used. Preferably the amount is 2-6 mmole diisocyanate per 100 g resin.

The reaction of the mixture of components (I) and (II) with the diisocyanate takes place in an inert solvent, for example aromatic hydrocarbon or ketones at 80-120 ° C. After the completion of the reaction, which can be determined by keeping the limit viscosity number constant, the solvent is removed in vacuo.

The carboxyl groups of the mixture or the after-treated combination of the components (I) and (II) are optionally applied to the solid resin part in an amount of up to 20%, after distillation of the water-soluble solvent in a vacuum and addition of auxiliary solvents. , partially neutralized with an inorganic or organic base.

Alcohols and ether alcohols are suitable as auxiliary solvents; preferred is the monobutyl ether of ethylene glycol. Triethyl-30 amine and dimethylethanolamine or mixtures of these amines, optionally also with other amines, are preferably used for partial neutralization of the carboxyl groups. Ammonia or an alkali metal hydroxide, preferably potassium hydroxide, can also be used for neutralization for certain applications. An advantage of the emulsions according to the invention is that only a small amount of amine is required, corresponding to the neutralization of up to 15 acid number units. This shows that the volatile amine content in the emulsions according to the invention can be kept below 1% by weight.

8301560 ί * -10-

Finally, the water is stirred in with stirring for 1 to 3 hours at a temperature between 40 and 60 ° C. Milky, thin-layer transparent emulsions with good storage stability are formed. They can be processed into quick-drying 5 base coats and topcoats without special problems. Application can take place in pigmented or non-pigmented form, optionally after addition of the usual coating auxiliaries, by ironing, dipping, spraying, flowing and others. Drying takes place at room temperature; forced drying is preferred in industrial serial coatings.

The following examples serve to illustrate the invention. All parts or percentages indicated are by weight unless stated otherwise. The indicated limit viscosity numbers were determined in chloroform (CHF) at 20 ° C and indicated in ml / g -15.

Explanation of the abbreviations VT used in the examples; Vinyl Toluene ST 1 Styrene MMA: Methyl Methacrylate 20 BA n-Butyl Acrylate BMA; n-butyl methacrylate IBMA; Isobutyl methacrylate MACS: Methacrylic acid ACS ': Acrylic acid 25 MIPS: Maleic monoisopropyl ester MBE: Maleic mono-n-butyl ester Butyl: Ethylene glycol monobutyl ether TDI: Toluylene diisocyanate (commercial mixture of 2,4- and 2,6-isomers DMH: 20% Ethyl amethanol) 30% DAPA: Diethylaminopropylamine TEA: Triethylamine [1¾]: Limit viscosity number, CHF / 20 ° C, ml / g SZ: Acid number, mg KOH / g 35 OHZ; Hydroxyl number, mg KOH / g FKP: Solid content (%) 8301560 -11- 1. Preparation of the emulsifier component (I).

1.1. Preparation of the PEG-containing polyol ester (a).

O

The raw materials shown in Table A are heated at 250 ° C and esterified under an azeotropic removal of the reaction water to an acid value below 2 mg KDH / g.

TABLE A.

1 2 3 4 5 6 7 10 linseed oil 800 680 640 - - 780 852

Safflower oil - - 800 - Dehydrated castor oil - 120 - - - - - Low molecular weight 15 polybutadiene (1) - - 160 - - - Tall oil fatty acid (2) - 790 Dehydrated castor oil fatty acid 56 - 56 56 75 41 20 Linseed oil fatty acid 56 -

Pentaerithritol - - - 110 PEG (M 1500) 150 150 150 150 90 200 110 PEG (M 1000) 30 25 PEG (M 3000) - - - 30

Dibutyltin oxide (Catalyst) 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Yield about (3) 1002 1002 1002 1002 999 1000 1000 (1) liquid polybutadiene with a viscosity of about 0.5 30 Pa.s / 20 C and a cis content of about 80%.

(2) commercial tall oil fatty acid with a resin acid content of less than 2%; iodine number about 150.

(3) «mixture minus reaction water 1.2. Graft copolymerization of the polyol ester (a).

About 80% of the polyol esters (a) are placed in a suitable reaction vessel and heated to 130 ° C. The remainder of this component is mixed uniformly with the monomers over about 6 hours, with a 3 parts mixture terted simultaneously from a separate addition vessel. -butyl perbenzoate and 7 parts of xylene add (these amounts refer to the values indicated in Table B)

5 mixtures). After the addition has ended, the temperature is raised to 140C

increased and maintained at this value until a solids greater than 9% and the desired limit viscosity number [^] CHF, 20 ° C is reached. If necessary, correction is made with still further peroxide. The unreacted monomers or the solvent present are then removed by vacuum and the mixture is diluted with BUGL to a solids content of 87%.

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8301560 -14-

The component 1/11 corresponds in its composition to the component 1/1, however [f] was increased to 14 ml / g by further addition of peroxide. raised.

The component 1/12 also corresponds to the component 1/1 with regard to its composition 5, however the MIPE was built in by addition. The polyol ester was reacted with the corresponding amount of maleic anhydride at 220 ° C for 2 hours and the anhydride structures were subsequently opened with isopropanol at 90 ° C for 4 hours. The further process steps took place as in the preparation of component 1/1.

2. Preparation of the urethane-modified binder (II.

The composition and constants of the urethane-modified alkyd resins or the urethane oils can be found in Table C.

15 TABLE C.

II / l II / 2 II / 3 II / 4

Part 1

Tall oil fatty acid - 500 510 - 20 Conjuvandol. 50 + ^ - 150

Safflower oil 300 - -

Dehydrated castor oil (D.C.O.) 120 - - - linseed oil 32 s ^ - - - 346

Pentaerythritol 86 204 204 41 25 Trimethylolpropane 9 - - 13

Benzoic acid 8 - - - p-t.-Butyl benzoic acid - - 90

Calcium octoate (4% Ca) 1 - - 0.3

Lead octoate (10% Pb). 0.5 - - 0.15 30 Part 2

Phthalic anhydride 90 90 100

Part 3 TDI 82 165 154 106.5 35 Part 4 DMEA - 19 18 8.5 DAPA 10.2 8301 560 -15-

Continued TABLE · C._II / l II / 2 II / 3 II / 4

TDI content (%) 11.9 15.3 15.1 20.7

Amine number (mg KOH / g) 6.1 10.9 11.1 10.3 5 Limit viscosity number (CHF) 13.1 9.9 11.1 10.9

Solid about 91% 91% 91 * 91% +) Isomerized! technically linear fatty acid with approximately 50% conjugated linoleic acid.

10 ++) Thermally polymerized linseed oil (vise. 32 s DIN 53 211/20 ° C

The urethane-modified binders are prepared in the following manner: In II / 1 - II / 3, a low molecular weight alkyd resin with an acid number below 2 mg KOH / g is obtained from part 1 and part 2 by esterification at 220 ° C. prepared. In II / l, the oils used in Part 1 must be transesterified with the polyalcohols before adding Part 2. This is done by heating part 1 at 250 ° C until a sample, 1: 6 diluted with ethanol at 20 ° C, is clearly soluble.

At 1/4, part 1, as in II / 1, is transesterified.

The reaction of the thus-obtained precursors with the diisocyanate and the amine is effected in a 70% solution in toluene.

The precursors dissolved in 90% of the required toluene are heated to 50 ° C. Then the TDI is added and the solution heated to 70 ° C. It is now held at 70 ° C until a control sample indicates that the content of free NCO groups has fallen to about 50% of the theoretical baseline. Then the DMEA and DAPA, diluted with the remaining toluene, are added and the temperature raised to 100 ° C. This temperature is maintained until the NCO content has fallen below 0.1% and the desired limit viscosity number has been prepared. When required, small amounts of TDI are added. The toluene is then distilled off in vacuo to such an extent that the resin has a solid content of about 80%. Now 10 parts of ethylene glycol monobutyl ether on 100 parts of solid resin are added and further distilled in vacuo until the toluene is completely removed.

Examples I-XV.

The composition and constants of the emulsions according to Examples I-XV are summarized in Table D below. The viscosity of the emulsions was measured with a rotary viscometer BROOKFIELD RVT, 8301560 <'u _' 1 '.

-16-. . -: - ¾ spindle 6, 100 rpm determined at 20 ° C.

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The preparation of the emulsions was carried out as follows: Emulsifier component (I) urethane modified binder (II) and BUQL were mixed well at 80 ° C for 60 minutes- Then the temperature was lowered to 60 ° C and the mixture of amines stirred in . After 30 minutes the addition of the water was started. The water was added over 60-90 minutes with vigorous stirring, maintaining the temperature between 60 and 50 ° C. The mixture was then stirred for another 30 minutes. A solids content of 45% was obtained with these mixtures.

Testing the emulsions according to example I-XV.

10 1. Test of storage stability.

To shorten the test duration, the emulsions were diluted to 30% and stored at 70 ° C. It is true that there is no certain key by which to conclude from the result of this storage power test under normal conditions. Experience has shown, however, that emulsions over a week under these conditions can be stored for at least 1 year under normal conditions. The emulsions according to Example I-XV showed no change after this test.

2. Testing of white lacquers.

The emulsions were treated with 2% of a water-tolerant sikka (S) mixture (eg HYDROCURE, MOONEY, USA; contains 5% Co) and 1% of an anti-skinning agent (each based on solid resin) and diluted to 35% with deionized water, then pigmented with titanium dioxide (eg RCR 3 from Tioxide Ltd., UK) 25 in a vibratory mill ("Red Devil") in the pigment: binder ratio 1: 1. After application of the lacquer to glass strips, drying, gloss and water resistance of the film at a dry film thickness of 30 µm. When testing the water resistance (24 hours storage in water at 20 ° C after 7 days drying at room temperature), the products according to Examples I-XV showed no slight softening without exception. The paints regenerate after a short time without loss of shine.

The drying test is carried out with a "BK-Drying Recorder" (The Mickle Laboratory Engineering Co. England). In the evaluation, 35 mean:

Procedure: Start of a permanent needle track (V in minutes) 8301560 -18-

Dried: Needle track on it. film area (A in minutes)

Dried: End of the needle track visible to the naked eye (D in hours).

The gloss test is carried out with the aid of a

5 Q

Gonioreflectometer "GR-COMP" (Fa. Paar. AT); measuring angle 60, indication: Percentage against standard.

TABLE E.

Results of the drying and gloss test.

10 Example Drying Shine

VA D

1 45 120 6 .78 2 - 30 90 3.5 69 3 50 105 5.5 80 15 4 55 135 5 75 5 50 105. 4.5 70 6 60 150 7 72 7, '50 150 6.5 70 8 45 105 5 65 209 45 105 * 5.5 75 10 35 90 3.5 69 11 35 90 4 65 12 50 150 6, 5 76 13 30 75 3 .68 25 14 50 150 6 74 15_ 35_90_4,5_ 77 3. Testing of an anti-corrosion primer based on the emulsions according to the invention.

222 parts of emulsion according to example 1/45% are ground in the usual manner with 50 parts of iron oxide red, 50 parts of lead silica, 70 parts of barium sulfate and 30 parts of talc and after addition of 2 parts of Hydro-Cure (see above), 1 dl of anti-skin agent, 1 dl of anti-scaling agent and 1 dl of defoamer on the roto-thinner diluted with water to a viscosity of 4 mPa.s (about 64% solids content). The pH value is further adjusted to 9.0 to 9.5 with TEA.

8301560 -19-

The color shows no change when stored for 4 weeks at 40 ° C. The drying test on the BK-Drying Recorder gave the value 30/75/3 for V / A / D. In the salt spray test (ASTM B 117/64), films dried at room temperature for 7 days after a test time of 120 hours do not show cross-rusting under rust; release at the cross cut was 1-2 mm.

Preparation of the emulsions with post-treated resin combinations.

1. Preparation of the emulsifier component (I).

1.1. From 800 parts of linseed oil, 56 parts of dehydrated castor oil fatty acid, 150 parts of PEG (M 1500), a polyol ester with an acid number less than at a temperature of less than azeotropic was added in the presence of 0.3 parts of dibutylation oxide at 250 ° C under azeotropic separation of the water of reaction. 2 mg KOH / g prepared.

1.2. 560 parts of this polyol ester 15 (1.1.) Were placed in a suitable reaction vessel and heated to 130 ° C. A mixture of 140 parts of the polyol ester (1.1.), 150 parts of vinyltoluene, 90 parts of isobutyl methacrylate, 40 parts of acrylic acid and 20 parts of maleic monoisopropyl ester and a mixture of 30 parts of tert-butyl perbenzoate and a second addition vessel was then added in about 6 hours. 70 parts of 20 xylene added. After finished addition, the temperature was raised to 140 ° C and held at this value until a solids content of more than 90% and a limit viscosity number (CHF, 20 ° C) of 8.8 ml / g was reached. If necessary, correction was made with further peroxide. The unreacted monomers or the solvent present were then removed by vacuum.

The final product represented a limit viscosity number of 8.8 ml / g, an acid number of 37 mg KOH / g and a hydroxyl number less than 5 mg KOH / g.

1.3. Blowing with air. The reaction product from 1.2. is mixed with 0.02% of a 5% solution (based on the metal content) of a commercial cobalt octoate and heated to 130 ° C. Air was then blown through the mass until a peroxide number of 45 and a limit viscosity number of 10.2 ml / g were reached; the acid number was 35 mg KOH / g (emulsifier component 1/1).

A further mixture was blown under the same conditions until a peroxide number of 42 and a limit viscosity number of 13.0 ml / g 8301560 -20- were reached; it was 1 in 1. in this case 33 mg KOH / g. The solids content in both blends was 100% (emulsifier component 1/2).

2. Preparation of the urethane-modified binder (component II)

5 Composition and constants are shown in Table F below

are borrowed.

TABLE F.

Component (II) II / 1 II / 2 II / 3 II / 4 part 1 10 Tall oil fatty acid 280 - 280 260

Linseed oil fatty acid - 280

Benzoic acid - - - 20

Glycerol 138 138 70 70

Trimethylolpropane - - 100 100 15 part 2

Phthalic anhydride 100 100 100 100 part 3

Toluylene diisocyanate 125 130 128 133 (TDI) 20 part 4

Dimethylethanolamine 10.4 10.5 11 11 (DMEA)

TDI content (%) 20.0 20.7 19.4 20.0 25 Fatty acids (%) 45 44.6 42.5 39

Solid about% 60 60 60 60

Limit viscosity, ml / g 12.3 16.4 10.8 12.5

Amine number, mg KOH / g 10.5 9.9 10.2 10.1 The urethane-modified binders were prepared according to the following procedure: From parts 1 and 2, a low molecular weight alkyd resin with a acid number below 2 mg KOH / g. The reaction of the thus-obtained precursor with the diisocyanate and the amine was carried out in a 60% solution in toluene. The precursors dissolved in 90% of the required toluene were heated to 50 ° C. The TDI was then added and the solution heated to 70 ° C. It was now held at 70 ° C until a control sample indicated, that the content of free NCO groups had fallen to about 50% of the theoretical baseline. Then the DMEA was diluted with o the remaining toluene added and the temperature raised to 100 ° C.

- This temperature was maintained until the NCO content fell below 50/1% and the desired limit viscosity number was reached.

If required, small amounts of TDI were added afterwards.

3. Cross-linking of components (I) and (II) with TDI.

In accordance with the mixing ratios indicated in Table B, the components were heated to 50 ° C. After addition to the TDI, the temperature was raised to 100 ° C. The reaction was finished after 6 hours.

The constants are listed in Table G.

TABLE G.

15 Resin combination III / 1 III / 2 III / 3 III / 4

Component 1/1 35 38 40 40

Component II / l 108 - - 100

Component II / 3 - 103 20 Component II / 4 - - 100 TDI 0.3 0/6 0/4 0.7

Solids content% 70 71 71.5 72

Limit viscosity number 25 ml / g 13.1 12.5 12.9 14.8

Millimol TDI per 100 g resin 1.7 3.5 2.3 4.0

Examples XVI - XX.

Composition and constants of the emulsions according to Examples XVI

- XX are summarized in Table H. The viscosity of the emulsions was measured with a rotary viscometer BROOKFIELD RVT, spindle 6, 100 rpm at 0 ° C.

The combinations from components (I) and (II) were heated to 100 ° C and about half of the toluene present was distilled off in vacuo. After addition of the BÜGL, the rest of the toluene was distilled off. After cooling to 60 ° C, the amines were added. After 30 minutes, the addition of the water was started. The water was added over 60-90 minutes with vigorous stirring, maintaining the temperature between 60 and 50 ° C. The mixture was then stirred for another 30 minutes. A solid content of 45% was obtained in these mixtures. 5 obtained.

TABLE H.

Example XVI XVII XVIII XIX XX

Component 1/2 40 - τ - - 10 Component II / 2 100 -

Combination IIl / l - 143 - - -,

Combination III / 2 - - 141

Combination III / 3 - - - 140 15 Combination III / 4 - - - 139

Toluene 40 43 41 40 39 BUGL 15 15 15 15 15 TEA 1.44 20 DMEA 0.64

Water 105 pH value 9.9 10.4 10.1 9.9 9.8

Viscosity, Pa.s 3.2 3.8 4.9 5.2 6.1 BUGL% 6.75

Amine% 0.94

Testing of the emulsions according to examples XVI - XX.

The emulsions were tested as in Examples I-XV for storage stability, drying, as well as in a white lacquer and an anti-corrosion primer. The products according to the present invention do not show any significant differences from the test numbers indicated there. On the other hand, essential improvements were obtained with regard to the cold stability of the emulsions and the surface drying of the films.

8301560 ^ Λ * 1 - -23-

Testing of, the cold resistance.

The emulsions were stored at -23 ° C for 16 hours and were evaluated for their properties after an additional 8 hours at room temperature (22 ° C).

An emulsion according to Example 1 served as a comparison.

5 - The emulsions according to Examples XVII - XX showed no change even when the freeze-thaw cycle was repeated.

The emulsion according to example XVI (without TDI cross-linking) showed an impeccable cold resistance down to -15 ° C, while the comparative test with the emulsion according to example I already coagulated irreversibly at -8 ° C.

Test of tack-free drying.

White lacquers were prepared from the emulsions. In addition, the emulsions with 2% of a water-tolerant sulfur mixture (for example B. HYDROCURE®, MOONEY, USA, contains 5% Co) and 1% of 15 were anti-skin-forming agent (each based on the solid resin) and diluted to 35% with deionized water. Then they were pigmented with titanium dioxide (eg RCR 3 from Tioxide Ltd., UK) in a vibratory mill ("Red Devil") in the pigment binder ratio 1 1. The lacquers were applied to glass strips with a dry film thickness of 20 µm For the examples XV-XX a tack-freeness of 1-2 hours was found In the comparative example (according to example I = without post-treatment) a time of 3-4 hours was obtained.

8301560

Claims (16)

Process for preparing air-drying aqueous emulsions of urethane-modified alkyd resins and / or urethane oils, which can be used as binders for non-pigmented or pigmented lacquers and paints, characterized in that 5 (I ) 25 - 50% by weight of an emulsion component water-soluble by neutralization with inorganic or organic bases, which has an acid number of 25 - 70 mg KOH / g, a hydroxy number of up to 40 mg KOH / g, a polyethylene glycol content of 7 up to 13% by weight and shows a limit viscosity number of 9 to 15 ml / g (determined in chloroform 10 at 20 ° C) and which by graft copolymerization from (a) 50-75% by weight of an acid number of less than 5 mg KOH / Polyethylene glycol-containing polyol ester of fatty acids, which exhibit an iodine number of 140 or more on average, with 15 (b) 17 - 45% by weight of vinyl and / or acrylic and / or methacrylic monomers, which have no further functional except the double bond display groups, and (c) 5 -8 wt% α, β-olefinically unsaturated carboxylic acids were obtained and 20 (11) 50-75 wt% of an air-drying urethane-modified alkyd resin and / or a urethane oil containing tertiary amino groups according to an amine number of 3-25, preferably 5-15 mg KOH / g bound, and a limit viscosity number between 8 and 20 ml / g (determined in chloroform at 20 ° C) shows 25 homogeneously mixed at 50-100 ° C and after partial neutralization of the carboxyl groups with an organic and / or inorganic base in an amount corresponding to an acid number of up to 15 mg KOH / g, and in the presence of up to 20 wt. % of an organic solvent which is water-bearing, emulsifies in water. 2. Process according to claim 1, characterized in that the polyethylene glycol-containing polyester is reacted by reacting equivalent amounts of polyunsaturated fatty acids and one or more polyethylene glycols in the presence from a naturally or synthetically prepared polyol ester of drying fatty acids, of which at least 75% of the double bonds are present as isolated double bonds. Process according to claims 1-2, characterized in that conjugated fatty acids and / or linseed oil fatty acids are used as unsaturated fatty acids in the component (1a). 4. Process according to claims 1-3, characterized in that linseed oil and / or 10 safflower oil or mixtures of this oil with a maximum of 15% by weight of a dehydrated castor oil are used as polyol ester in the preparation of the component (Ia). 5. Process according to claims 1-4, characterized in that for the component (Ia) a polyethylene glycol or several polyethylene glycols with an average molecular weight between 1000 and 3000 are used. Process according to claim 5, characterized in that the polyethylene glycol or a mixture of polyethylene glycols used has an average molecular weight of 1500 + 200. 7. Process according to claims 1-6, characterized in that up to 30% by weight of the polyol ester used in the component (Ia) is replaced by an unsaturated hydrocarbon oil, preferably a lower molecular butadiene polymer. 8. Process according to claims 1-7, characterized in that as monomer without further functional groups (b) mixtures of 60 - 78 wt.% Monomers are used, which are gasoline-soluble polymers with a glass transition temperature (Tg) of more than 70 ° C, preferably vinyl toluene and 22-40% by weight monomers, which form gasoline-soluble polymers having a glass transition temperature (Tg) below 70 ° C, preferably 20 to 60, preferably n-butyl and isobutyl methacrylate, 30 applies. 9. Process according to claims 1-8, characterized in that as α, β-olefinically unsaturated carboxylic acids acrylic acid or mixtures of at least 50 mol% acrylic acid with other α, β-olefinically unsaturated carboxylic acids are used. Process according to Claims 1 to 9, characterized in that half-esters of maleic acid with monoalcohols having 3-8 carbon atoms, preferably isopropyl maleinate, are used as α, β-unsaturated carboxylic acids. 8301560 <* -26- 11. Process according to claims 1-10, characterized in that minor amounts of maleic acid semesters are added by addition of maleic anhydride to the unsaturated fatty acids and reaction of the anhydride structure with the corresponding monoalcohols in the component (I). implemented. Process according to claims 1-11, characterized in that as component (II) urethane-modified alkyd resins and / or urethane. oils are used, which are characterized by the following key areas: 10 content of unsaturated oil fatty acids 45 - 70% content of aromatic or cycloaliphatic monocarboxylic acids 0 - 20% content of polyalcohols 15 - 25% content of dicarboxylic acids 0 - 16% 15 content of diisocyanates 8 - 25% acid value below 5 mg KOH / g hydroxyl number 0 - 80 mg KOH / g limit viscosity (? £): 8-16 ml / g 13. Process according to claims 1-11, characterized in that for the emulsification with water, the component (I) is treated with air at 80 - 160 ° C, preferably 100 - 150 ° C, for a long time to a peroxide number of at least 20 milliequivalents per kg and an increase in the limit viscosity number (CHCl 2, 20 ° C) of at least 1 ml / g has been reached and / or the mixture of components (I) and (II) by 1.5 to mmol / 100 g of the resin mixture of an aromatic and / or aliphatic diisocyanate is converted in the presence of an inert solvent and the solvent is optionally removed from the reaction mixture for neutralization and emulsification by distillation. 14. Process according to claim 13, characterized in that the component (II) used is urethane-modified alkyd resins which exhibit the following limit values: content of unsaturated fatty acids 35 - 70% content of aromatic or cycloaliphatic monocarboxylic acids 0 - 25% 35 content of polyalcohols 15 - 30% content of dicarboxylic acids 0 - 20% content of diisocyanates 8 - 25% acid number below 5 mg KOH / g hydroxyl number 0 -100 mg KOH / g 40 limit viscosity (2?): 8-20 ml / g 8301560 X * -27- Process according to Claims 13 to 14, characterized in that the reaction with the diisocyanate takes place with components having a hydroxyl number of 20 mg KOH / g or more. 16. Method according to claims 13-15, characterized in that the blowing with air takes place in the presence of a sulfur, preferably a cobalt salt. 8301560