FR2552769A1 - Prepn. of alkyd resin emulsion - Google Patents

Abstract

Aq. emulsions of oxidatively drying alkyd resins, modified with polyethylene glycol (PEG) are prepd. by (I) reacting (a) 25-50 (30-45) wt.% of a copolymer of 30-55 wt.% unsatd. fatty acids, 10-25% methacrylic acid and 30-60% vinyl(idene) cpds. contg. no functional gps. other than the C=C bond, with (b) 5-15 (8-12)% PEG with mol.wt. 1000-3000, and (c) 35-70 (40-65) % of polyols and mono- and di-carboxylic acids used for alkyd resins, to give an acrylic-modified alkyd resin with acid number 40-70 mg KOH/g and intrinsic viscosity 5-8 ml/g in CHCl3, (II) partially esterifying 30-50 wt.% of this component with 70-50% of an alkyd contg. 15-50% drying fatty acids, with acid number less than 5 mg, OH number 50-150, and intrinsic viscosity 8-13 ml/g, at 160-200 deg.C, pref. using an azeotropic entraining agent, to acid number 10-25 and intrinsic viscosity 10-16 ml/g, and (III) emulsifying the alkyd resin combination, contg. 3-6% PEG, in water by neutralising the acid gps. with (in)organic bases, pref. ammonia or organic amines, and with addn. of not more than 20 wt.% or organic auxiliary solvents.

Description

Method of oroaration of emulsions
alkyd resins which dry oxidation
The subject of the invention is a process for the preparation of aqueous emulsions of alkyd resins with improved drying properties.

 Austrian patent AT 372,097 claims a process for the preparation of aqueous emulsions of polyethylene glycol-modified alkyd resins and oxidatively drying. which are suitable for the formulation of oxidative drying lacquers or varnishes. This process is characterized in that 70 to 85% by weight of a low molecular weight alkyd resin intermediate containing 15 to 45% by weight of drying fatty acids is esterified.

said intermediate having an intrinsic viscosity index of between 4.5 and 8.5 ml / g (measured in chloroform at 20 ° C.), an acid index of less than 10, preferably less than 5 mg of KOH / g, an index of hydroxyl of 80 to 200 mg of KOH! g and a content of 4 to 8 Z by weight of a polyethylene glycol (PEG) inserted into the structure by esterification, optionally in the form of mixtures of intermediates of alkyd resins containing
PEG and PEG-free intermediates with 15 to 30 Z by weight of a polymerized product prepared by copolymerization of 10 to 25 Z by weight of methacrylic acid with 30 to 55 Z by weight of unsaturated fatty acids and 30 to 60 Z by weight of vinyl and / or vinylidene compounds containing, in addition to the double bond, no other functional group, said esterification reaction between these two products being continued until an acid number of 10 is obtained at 25 mg KOH / g and an intrinsic viscosity index of 8 to 15 ml / g measured in chloroform at 20 ° C., the modified alkyd resin thus obtained which has a PEG content of between 3.4 and 6 Z by weight. being emulsified in water by the addition of at most 20% by weight of organic auxiliary solvents, this emulsification taking place at the same time as neutralization of the acid groups using ammonia or organic amines.

 In practice, the products prepared according to the Austrian patent AT 372.097 have proved their worth, in particular in lacquers or varnishes subjected to forced drying, an application which, moreover, is indicated in the patent in question as preferential (page 4, lines 41 and following).

 In the field of aqueous emulsions of alkyd resins, however, there are no more than before, products capable of withstanding the comparison with regard to drying at normal temperature, that is to say at about 15-25- C, with the corresponding alkyd resins based on solvents or on polymer dispersions without it being necessary to accept drawbacks relating to other properties such as emulsion stability or film-forming properties.

 It has now been found that, starting from the basic concept of the Austrian patent AT 372.097, it was possible, by modifications of the molecular structure of the binding agents, to produce emulsions which no longer have the disadvantages of the products. of the state of the art.

 In the course of research relating to the molecular structure of alkyd resins according to Austrian patent AT 372,097, it has been found that each of the fundamental properties of an emulsion. namely the emulsion stability, the pigment wetting and the drying capacity, exhibits a marked dependence on the average molecular weight M, expressed by the intrinsic viscosity index [91. It turns out, however, that the optimum domains for each of the properties do not overlap in the case of products according to the state of the art. While optimal gloss and good paint stability (as a function of pigment wetting) are obtained within a range of [n] CHCl / 20- less than 10 ml / g. it turns out that the favorable areas with regard to the speed of drying and the emulsion stability correspond to values in each case different but greater than 10 ml / g with an optimum of between 12 and 14 ml / g. Due to this displacement, it follows that within the range usable for the stability of paints of less than 10 ml / g, the drying capacity of the alkyd resin can only be used up to about 50 Z.

 The object of the invention is therefore to bring the optima as close as possible to the various criteria.

 It has been found that, surprisingly, by a modification of the process according to the Austrian patent AT 372.097 and by the corresponding modification in the molecular structure, it was possible to solve this problem without losing the excellent fundamental properties of the emulsions according to the invention. 'state of the art.

The present invention therefore relates to a process for the preparation of aqueous emulsions of oxidatively drying polyethylene glycol-modified alkyd resins which is characterized in that (I) is reacted from 25 to 50, preferably from 30 to 45 X
by weight of a copolymerized consisting of
30 to 55% by weight of unsaturated fatty acids.

10 to 25% by weight of methacrylic acid and
30 to 60% by weight of vinyl compounds
or vinylidene containing,
in addition to the double bond. at
no other functional group,
with
5 to 15, preferably 8 to 12% by weight of polyethyl-
neglycol (PEG) with a molecular weight between
1000 and 3000
and
35 to 70, preferably 40 to 65% by weight of polyols,
monocarboxylic acids and dicarboxylic acids
conventional in the context of re preparation
alkyd sines.

until an acryl-modified alkyd resin having an acid number of 40 to 70 mg of KOH / g, an intrinsic viscosity index [n] CHCl3 of 5 to 8 ml / g, is obtained.
CHCl3 percentages being relative to the constituent parts contained in the reaction product and their sum being equal to 100, and (11) partially esterified
from 30 to 50% by weight of the above constituent with
from 50 to 70% by weight of an alkyd resin having a
drying fatty acid content -15 to
50 Z, an acid number of less than 5 mg
KOH / g. a hydroxyl number of 50 to
150 mg KOH / g and a viscosity index
intrinsic tee [r '] CHCl3.20. from 8 to
13 ml / g at 160-200-C, preferably with the use of an azeotropic entraining agent, until an acid number of 10 to 25 mg of KOH / g is reached and an intrinsic viscosity index [n] CHCl of 10 to 16 ml / g.

3. 20 and (III) the combination of resins is emulsified in water
alkyds thus obtained. which has a content of
PEG from 3 to 6 Z. with addition of at most 20 Z in
weight of organic auxiliary solvents,
acid groups being neutralized using bases
mineral or organic, preferably using
ammonia, or organic amines.

 Compared to the products according to the state of the art, the binders prepared in accordance with the invention exhibit significantly improved drying. which results both in a shortened initial drying time and in an improved core drying. Another advantage of the alkyd resins prepared in accordance with the invention lies in an improved reproducibility of the results, which is made possible by the higher regularity which can be achieved in this process as regards the quality of the individual fillers.

 The acryl-modified alkyd resins prepared in step (I) have a PEG content of 5 to 15, preferably 8 to 12%, the polyethylene glycols used having a molecular weight of 1000 to 3000.

 The insertion of polyethylene glycol (PEG) can be done in various ways. for example by direct esterification or by etherification using esters of fatty acids and epoxides and subsequent transesterification, as described in the Austrian patent AT 365,215. Another process is that described in Austrian patent AT 365,216 in which the PEG is inserted by means of phenolic resols.

 For the insertion of the carboxylic groups necessary for the stabilization of emulsions. are used, in accordance with the invention, polymers which are prepared by polymerization with free radicals of 10-25 Z by weight of methacrylic acid, 30-55 Z by weight of a drying oleic fatty acid with an index of iodine of at least 125 and 30-60% by weight of one or more vinyl and / or vinylidene compounds, in particular acrylic compounds which, apart from the double bond, do not contain groups capable of reacting.

 As drying fatty acids, those with conjugated double bonds are used - such as dehydrated castor oil fatty acids or isomerized fatty acids - or those with isolated double bonds - such as fatty acids soy, safflower or linseed oil techniques. Since fatty acids with isolated unsaturations have a lower reactive capacity, they should be used in the form of a larger excess. Insofar as, during the polymerization, the fatty acid does not react completely, the radical is inserted into the alkyd resin during the esterification.

 As vinyl or vinylidenic compounds, it is possible to use styrene, vinyltoluene, vinyl ester of acetic acid, propionic acid or acid marketed under the name of acid " The alkyl esters in the trade of acrylic and methacrylic acids are used in a preferred manner. The selection takes into account, among other things, the compatibility with the alkyd resin intermediate. As a general rule, the polymers having the best compatibility also exhibit the better emulsifying effect.

 The polymerization is carried out at 80 up to 160 ° C. As initiators. it is possible to use any compound providing radicals and decomposing in this temperature range. To adjust the molecular weight, it is possible to use the usual polymerization adjusting agents such as tert. - dodecylmercaptan. For the preparation of the copolymers, the main part of the fatty acids is introduced into the reaction vessel and possibly mixed with inert solvents. After the reaction temperature has been reached, the other acids are introduced regularly. fatty, the monomers, as well as the peroxide and optionally the adjusting agent, in the form of a mixture and within 3 to 10 hours depending on the reactivity of the fatty acids. The end point of the polymerization is considered to be the fact that the dry extract becomes constant.

that is to say the practically total disappearance of the volatile monomers from the reaction mixture. Limit viscosity index of the polymers or of the mixture of polymers with unreacted fatty acids is between 4 and 9 ml / g, measured in dimethylformamide at 20C. In the case of the indicated reaction conditions, side reactions such as dimerization of fatty acids are largely inhibited. It follows that the fatty acids not inserted by polymerization remain unchanged and continue to exhibit, after insertion into the alkyd resin, their oxidative crosslinking capacity.

 In addition to the PEG and the copolymer, the acryl-modified alkyd resins prepared according to step (I) contain the usual raw materials. As polyols. pentaerythritis as well as trimethylolpropane, glycerol, sorbitol and optionally other diols are preferably used. The fatty acids used have iodine indices of more than 125. In addition to the usual dicarboxylic acids, such as for example the various phthalic acids. it is also possible to use monocarboxylic acids such as benzoic acid or p-tert.-butylbenzoic acid.

 The modified alkyd resins prepared in step (I) have a fatty acid content of 20 to 60%. The esterification of the constituents is carried out under conventional conditions up to an acid number of 40 to 70 mg KOH / g and an intrinsic viscosity index [r '] CHCl3 .20 from 5 to S ml / g.

In step (II), partially esterified from 30 to 50% by weight of the acrylic alkyd resin or
PEG-modified, with 50 to 70Z by weight of a conventionally prepared alkyd resin. The alkyd resins used and containing no PEG have the following characteristics
Unsaturated fatty acid content: 15 - 50 g.

(iodine index greater than 125)
Acid number: less than 5 mg KOH / g
(preferably less than 3 mg KOH / g)
Hydroxyl number: 50 - 150 mg KOH / g
Viscosity index
intrinsic [n] CHCl. 20 "8 8 to 13 ml / g
3
The two constituents are combined, in step (II), in weight proportions such that the PEG content is around 3 to 6%. The acid number of the product results from the proportion of methacrylic acid which in the final product. is 1.5 to 4.5 Z. The two constituents are partially esterified at 160-200 ° C, the reaction water being removed by an azeotropic entraining agent. Before reaching the final value, the entraining agent is eliminated by setting up a vacuum. The partial esterification is continued until an acid number of 10 to 25 mg of KOH / g and up to an intrinsic viscosity index [r '] CHC1 of 10 to
CHCl3.20 C 16 ml / g. Efforts are preferably made to reach ranges of 12 to 20 mg of KOH / g as regards the acid number and 12 to 15 ml / g as regards the intrinsic viscosity number.

 In step (III), the resins are started to dissolve with at most 20% by weight. preferably from 5 to 15% by weight of organic auxiliary solvents, then emulsifying them in water at temperatures between 40 and 50 ° C, this water containing an amount of ammonia, organic amines or d alkali hydroxides which correspond to that necessary for neutralization of 50 to 100% of the acid groups of the resin. As auxiliary solvents, these are above all alcohols or ether alcohols, such as n-butanol or ethylene glycol ether monobutyl, which are suitable, as amines, for example, triethylamine or dimethylethanolamine.

 The products prepared according to the process according to the invention serve, after corresponding drying, as bases for lacquers or varnishes dilutable with water and drying oxidatively which can be put in place by any suitable conventional process, which also dry well at temperature normal only at a high temperature and which, above all, are suitable for industrial application.

 When using alkyd resins having a fatty acid index of 40 Z or more, emulsions prepared in accordance with the invention can be used for the preparation of wood stain dilutable with water. Furthermore, these resins are appropriate. thanks to their compatibility, to the preparation of lacquers or varnishes based on combinations of acrylic polymer dispersions.

 For the siccativation, the conventional water-dilutable siccatives are used in the proportions well known to those skilled in the art.

 The following examples illustrate the process according to the invention. All the parts indicated are parts by weight. Unless otherwise indicated, the figures given for the limiting viscosity index have been determined in chloroform at 20 ° C.

(I) PreDaration of cooolvmérisats
P 1 copolymer
In a suitable reaction vessel equipped with a reflux condenser and a supply device, 40 parts of xylene, 40 parts of isopropanol are brought to the reflux temperature (approximately 95 ° C.). 60 parts of linseed oil fatty acids, 11 parts of isobutyl methacrylate, 1 part of ethylhexyl acrylate, 2 parts of vinyltoluene, 6 parts of methacrylic acid and 3 parts of dibenzoyl peroxide as well as 0 , 2 parts of dodecylmercaptan and a mixture of 44 parts of isobutyl methacrylate, 4 parts of ethylhexyl acrylate, 8 parts of vinyltoluene, 24 parts is added over a period of 5 hours uniformly and at this temperature methacrylic acid and 0.8 part of dodecylmercaptan as well as a mixture of 10 parts of xylene. 10 parts of methyl ethyl ketone, 40 parts of linseed oil fatty acids and 11 parts of diben zoyl peroxide, always in the space of 5 hours and in a uniform manner, then polymerized at reflux temperature until almost complete transformation (determination of the dry matter content). If necessary, it is possible during this time to add an additional quarter of the amount of peroxide indicated.

 The copolymer has a fatty acid index (relative to the resin at 100 a) of 50 Z. a methacrylic acid content of 15 Z. a dry matter content of 65.5 Z and an intrinsic viscosity index [n] DMF, 20 * C 9 ml / g.

P 2 copolymer
50 parts of dehydrated linseed oil fatty acids are brought to a temperature of 145 ° C. and, over a period of 6 hours, a mixture of 55 parts of isobutyl methacrylate, 35 parts of methacrylic acid and 10 parts of vinyl toluene, as well as a mixture of 20 parts of dehydrated linseed oil fatty acids and 6 parts of tert-perbenzoate simultaneously.

butyl, these additions being made on a regular basis.

To complete the polymerization, the mixture is kept for an additional 8 hours at 145-C, it being understood that at intervals of 2 hours each time a mixture of 5 parts of xylene and 0.5 part of tert-perbenzoate is added three times. -butyle.

 The copolymer has a fatty acid index of 41.2 Z, a methacrylic acid content of 20.6 Z.

a dry matter content of 90.3 Z and an intrinsic viscosity index [r '] DMF.20 "C of 4.7 ml / g. (DMF dimethylformamide).

(II) Preparation of acrvl-modified alkv resins
Modified alkyd resin PA 1
100 parts of p.-tert.-butylbenzoic acid, 20 parts of benzoic acid, 160 parts of linseed oil fatty acids and 141 parts of pentaerythritol are brought to a temperature of 250 ° C. the whole at this temperature for 90 minutes. Then, at a temperature of 220 ° C., 120 parts of conjugated technical linoleic fatty acid, 100 parts of PEG 1500 are added. 64 parts of phthalic anhydride, 30 parts of anhydride tetrahydrophthalic and 376 parts of polymer polymer P2 at 90.3 Z.The whole is esterified at 180-C in the presence of xylene as a entraining agent until an acid number of 54 mg is reached KOH / g and an intrinsic viscosity index [r '] CHCl3. 20 'C of 6.8 ml / g. The resin has a dry matter content of 92 Z, a PEG content of 9.8 Z and a polymer content of 33 Z.

Modified alkyd resin PA 2
It is brought to 250 ° C. and maintained for 2 hours at this temperature, 200 parts of linseed oil, 130 parts of p.-tert.-butylbenzoic acid, 91 parts of pentaerythritol and 20 parts of trimethylolpropane. At 140 "C.

715 parts of polymer P1 are added to 65 Z and the temperature is brought back to 180 ° C. The solvent present under vacuum is then removed as completely as possible.

Then, 100 parts of PEG 1500 and 92 parts of phthalic anhydride are added and the whole is esterified in the presence of xylene as a entraining agent up to an acid number of 52 mg of KOH / g and up to an intrinsic viscosity index [n] CHC13,20'C of 7.1 ml / g. The dry matter content of the resin is 92%, its PEG content is 9.5% and the proportion of polymeris is 44 '.

(III) Alkyd resin with low acid number
The raw materials indicated in the table are esterified in a known manner at 240 "C in the presence of xylene as a entraining agent.
A3, the linseed oil is first transesterified with pentaerythritol and p.-tert.-butylbenzoic acid for 90 minutes at 250 ° C. After addition of the dicarboxylic acid anhydride at approximately 200 ° C., the esterification is carried out at 240 ° C. All the resins are diluted with xylene to a dry matter content of 80 X.

BOARD
Alkyd resin A 1 A 2 A 3 A 4 A 5
Pentaerythritol 110 110 93 110 110
P.-tert.-butyl acid
benzoic 140 120 120 90 130
Linseed oil - - 110 - -
Wood oil - - - - 110
Linseed oil fatty acids 40 60 - 100 -
Tall oil fatty acids - - - - 105
Oil fatty acids
dehydrated castor 45 45 - - -
Linoleic fatty acid
industrial conjugate --- - - 50 -
Phthalic anhydride 90 60 62 110 100
Tetrahydro anhydride
phthalic 20 42 45 - -
phthalic 20 42 45 - -
Fatty acid content, Z 20.6 25.9 25.9 35.0 40.0
Acid number
(mg KOH / g) 1.5 1.9 2.9 1.4 1.4
Hydroxyl number
(mg KOH / g) 95 115 90 95 85 [r '] CHC13,20 C (ml / g? 10.8 10.3 11.5 10.6 11.2 (IV) Examples according to the invention
EXAMPLE 1
68.75 parts of Al and 48.9 parts of PA1 (ratio of solid resins 55:45) are esterified at 180-C in the presence of xylene as entraining agent until an index is reached of intrinsic viscosity [r '] of approximately 11 ml / g and an acid number of approximately 20 mg of KOH / g. After removing the xylene under vacuum, the mixture is continued to maintain at 50 ° C. When the characteristic figures indicated below are reached, a sample is taken respectively and diluted with monoethyleneglycol-monobutyl ether (BUGL) until 'to a dry matter content of 85 Z. The solutions are mixed with triethylamine (TEA) according to their acid number, then diluted with deionized water to a dry matter content of 40 Z In all cases, opaque milky emulsions with a viscous structure are obtained, having a pH value of 9.2 to 9.4.

Sample 1 2 3
Acid number 17.8 17.5 17.3 [n] 1 2, 7 13.8 15.3
To measure the stability, the emulsions are stored for 3 months at 40 "C. After this test, the emulsions do not show any change, apart from a slight decrease in viscosity.

To examine the properties of paints. the emulsions are pigmented in a proportion of 1: 1 using
TiO2 (rutile ?, 3 Z of a siccative mixture compatible with water are added (1.2 Z of cobalt, 7.2 Z of barium, 3.2 Z of zinc). 1 Z of an anti-skin agent and 0.5% of a spreading agent, then diluted to the application viscosity using deionized water.

Lacquer properties M 1 M 2 M 3
Storage capacity, 40 "C ---- more than 4 weeks ---
Drying
dry to touch (minutes) 55 50 50
time out of
dust (minutes) 120 110 105
resistant to
grip (hours) 8 8 8
Pendulum hardness after Kônig (DIN 53157)
after 1 week 53 50 55
Shine
Gonioreflectometer
type VIANOVA GR - COMP, Z 78 74 75
This example shows that, in the selected field, there is no significant change in the emulsion stability and in the properties of the paints as a function of the intrinsic viscosity index and, consequently. also depending on the average molecular weight.

In a subsequent manner. the quality fluctuations of the different batches are low. The drying of paints or varnishes is comparable to that of industrial paints based on alkyd resins dissolved in organic solvents.

EXAMPLE 2
Analogously to Example 1, 75 parts of A2 are reacted with 43.5 parts of PA 1 (solids ratio 60:40). The result is a binding agent which has an acid number of 16.9 mg KOH / g and a [r '] of 13.9 ml / g. The resin is, as indicated in Example 1, emulsified in water. The emulsion stability at 40 "C is more than 3 months.

EXAMPLE 3
In a manner analogous to Example 1, 81.25 parts of A3 are reacted with 38.0 parts of PA 1 (proportion in dry matter 65:35). The binding agent has an acid number of 15.2 mg KOH / g and a [r '] of 14.3 ml / g. The resin is emulsified in water, as indicated in Example 1. The emulsion stability at 40 ° C. is greater than 3 months.

The emulsions according to Examples 2 and 3 are tested in the form of a paint for industry (pigment / binding agent 0.5: 1; molybdate red drying agent and auxiliary agent as in Example 1 ). The following results are recorded
Example 2 3
Suitability for storing paints (40 "C) more than 4 weeks
Drying
dry to the touch (minutes) 65 55
time out of
dust (minutes) 135 120
resistant to
grip (hours) 9 8
Pendulum hardness according to Kènig (DIN 53157) 42 48
Shine
Gonioreflectometer
type VIANOVA GR - COMP, Z 73 68
Example 4
As indicated in Example 1, 81.25 parts of A 5 are esterified with 38.0 parts of PA 1 up to an acid number of 14.6 mg of KOH / g and an [n) of 14, 3 ml / g; they are then diluted and emulsified in water after neutralization, (the proportions in solid matter are 65:35). The emulsion has a pH of 9.4. The emulsion stability at 40 ° C is more than 3 months.

 The emulsion is tested in an anti-corrosion primer.

To do this, 100 parts of solid resin are ground together with 50 parts of iron oxide red, 50 parts of lead silicochromate. 70 parts of barium sulphate and 30 parts of talc then, after addition of the siccative or additives (as in Example 1), diluted to the viscosity of application. The tests provide the following values
Stability of varnish or Low deposit. easily paints (4 weeks / 40 "C) suspended by shaking
Drying
dry to touch (minutes) 40
time out of dust (minutes) 65
grip resistant (hours) 6
Salt spray test after 1 week / 22-C
(ASTM 8 117-64)
after 120 hours weak rust formation
at the cross incision of
isolated bubbles covered with an industry paint according to Example 3, after 300 hours no attack
EXAMPLE 5
As indicated in Example 1, 75 parts of A 4 and 43.5 parts of PA 2 (proportion of dry matter 60:40) are reacted up to an acid number of 15.7 mg of KOH / g and up to a [r'J of 12.9 ml / g. The emulsion obtained from there, by proceeding as in Example 1, has a pH of 9.6 and an emulsion stability of more than 3 month at 40 "C.

From 20 parts of the emulsion (relative to the solid resin), 80 parts of solid resin of a commercial acrylate dispersion (Mowilith R LDM 7760 /
Hoechst), 0.6 parts of the siccative mixture also used in the other examples as well as 5 parts of a coalescing agent recommended for the dispersion (for example
R ple the product known under the brand TEXANOL), a paint for unpigmented wood is prepared and adjusted with deionized water to an application viscosity. Lacquer has a stability at 40 "C for more than 4 weeks and, due to its surface hardness, exhibits a resistance to scraping as required for the vitrification of floors. Applied to a glass plate, this paint is dry to the touch after 15 minutes, is dust-free after 30 minutes and resists gripping after 3 1/2 hours.

 A comparison lacquer not comprising the emulsion obtained in accordance with the invention remains all the time thermoplastic and sensitive to scratching.

Example 6
Just as indicated in Example 1. 75 parts of A 5 and 43.5 parts of PA 2 (proportion of dry matter 60:40) are reacted up to an acid number of 16.2 mg of KOH / g and up to a [n] of 13.6 ml / g. then we continue to transform them into an emulsion having a pH value of 9.5. The emulsion stability at 40 "C is greater than 3 months.

For the examination, a vitrified wood stain is made from 100 parts of emulsion (relative to the solid resin), 3 parts of siccative mixture (see example 1), 2 parts of anti-skin agent, 2 parts of spreading agent, 4 parts of fungicide and 20 to 30 parts of a coloring paste (for example that known under the
R brand "LUCOMYL" from BASAI, the whole being diluted to a solids content of 20% using deionized water.

 The first application supports a second application after one hour and the second application resists gripping after 24 hours. From the point of view of weather resistance. the two applications correspond to those of commercial stains based on solvents.

 As is obvious and as it already follows from the above, the invention is in no way limited to those of its modes of application and embodiments which have been more especially envisaged that it embraces, on the contrary, all variants.

Claims (9)

CLAIMS Process for the preparation of aqueous emulsions of oxidatively drying polyethylene glycol-modified alkyd resins, characterized in that (I) reacts from 25 to 50, preferably from 30 to 45% by weight of a copolymerized consisting of  30 to 55% by weight of unsaturated fatty acids.  10 to 25% by weight of methacrylic acid and  30 to 60 X by weight of vinyl compounds  or vinylidene containing,  in addition to the double bond, at  no other functional group,  with  5 to 15, preferably 8 to 12 X by weight of polyethylene  neglycol (PEG) with a molecular weight between  1000 and 3000  and  35 to 70. preferably 40 to 65% by weight of polyols.  monocarboxylic acids and dicarboxylic acids  conventional in the context of re preparation  alkyd sines. until an acryl-modified alkyd resin having an acid number of 40 to 70 mg of KOH / g is obtained, an intrinsic viscosity index [r '] CHCl3 of 5 to 8 ml / g, the percentages being relative to the constituent parts contained in the reaction product and their sum being equal to 100. and (II) partially esterified  from 30 to 50% by weight of the above constituent with  from 50 to 70% by weight of an alkyd resin having a  drying fatty acid content from 15 to  50 Z. an acid number of less than 5 mg  KOH / g, a hydroxyl number of 50 to  150 mg KOH / g and a viscosity index  intrinsic tee [#] CHCl3, 20 from 8 to  3  13 ml / g at 160-200 "C, preferably with the use of an azeotropic entraining agent, until an acid number of 10 to 25 mg of KOH / g and a intrinsic viscosity index [n] CHCl 3. 20 from 10 to 16 ml / g. and (III) the combination of resins is emulsified in water  alkyds thus obtained, which has a content of  PEG from 3 to 6 Z, with addition of at most 20 Z in  weight of organic auxiliary solvents,  acid groups being neutralized using bases  mineral or organic, preferably using  ammonia, or organic amines.