GB2112793A - Aqueous alkyd resin emulsions - Google Patents

Abstract

Alkyd resin compositions comprising (A) 25-45% by weight of an alkyd resin based on drying fatty acids modified with 4 to 10% by weight of acrylic and/or methacrylic acid and 7 to 13% by weight of a polyethylene glycol having a molecular weight of from 500 to 5000, the resin having an acid value of from 25 to 70 mg KOH/g and an intrinsic viscosity of from 9 to 12 ml/g (measured in chloroform at 20 DEG C); and (B) 55-75% by weight of a urethane modified air drying alkyd resin having an intrinsic viscosity of from 8 to 16 ml/g (measured in chloroform at 20 DEG C) when neutralised with appropriate bases such as amines and/or ammonia, may be emulsified in water and form the basis of binders for paints and varnishes. The emulsions formed have good air-drying properties.

Description

SPECIFICATION Aqueous alkyd resin emulsions The present invention is concerned with aqueous emulsions based on combinations of acrylated alkyd resins and urethane modified alkyd resins for air drying paints.

There are a number of patents describing acrylated alkyd resins as binders for water dilutable air-drying paints e.g. US-PS 4.133.786, GB-PS 1.117.126). Furthermore, the use of water dilutable urethane oils or urethane modified alkyd resins is also known (see EU 00 17 199, EU 00 18 665, DE-OS 17 45 343, DE-PS 2323 546, US-PS 4.017.514, US-PS 4.116.902) for air drying paints.

Both groups of binders have specific disadvantages: The acrylated alkyd resins, owing to the reduced reactivity of the unsaturated fatty acids due to the copolymerisation reaction, only show moderate cross-linking and thus poor resistance of the paint films. Furthermore they require a high level of volatile toxic amines for neutralisation of the acid groups. On producing paints from urethane oils or urethane modified alkyds they provide a number of problems on paintformulation, owing to poor pigment wetting and poor compatibility with driers. Furthermore, such binders require large amounts of amines to stabilise them in the form of emulsions.

It is also known to combine urethane oils or urethane modified alkyd resins, in emulsified form, with polyvinyl or polyacryl latices (US-PS 3.919.145). Owing to the inert non-crosslinkable latex portion, these emulsions only give poor films and can only be used for so-called house-paints.

It has now been found that air-drying emulsions can be obtained giving paints with superior paint performance by the emulsification in water of compositions comprising acrylic mofidied alkyd resins based on drying fatty acids and having an acid value of between 25 and 70 mg KOH/g and a content of about 10 % of polyethylene glycol, and air-drying urethane modified alkyd resins. Such emulsions contain only low levels of volatile amines, preferably less than 1 %, and are very stable. They exhibit excellent pigment wetting and can thus be formulated to give brilliant finishes or highly pigmented primers. They dry quickly, have little tendency to surface defects such as cratering or recession from edges and give films with good resistance characteristics.

It is known that acrylated alkyds and urethane modified alkyd resins normally have little compatibility with other binders. Thus it could not be foreseen that compositions of the above type would give synergistic enhancement of their desirable properties.

Accordingly, the present invention provides in one aspect water-emulsifiable alkyd resin compositions comprising (A) 25-45 % by weight of an alkyd resin based on drying fatty acids modified with 4 to 10 % by weight of acrylic and/or methacrylic acid and 7 to 13 % by weight of a polyethylene glycol having a molecular weight of from 500 to 5000, the resin having an acid value of from 25 to 70 mg KOH/g and an intrinsic viscosity of from 9 to 12 ml/g (measured in chloroform at 20"C); and (B) 55-75 % by weight of a urethane modified air drying alkyd resin having an intrinsic viscosity of from 8 to 16 ml/g (measured in chloroform at 20"C).

Resin component (A) preferably contains from 9 to 11% of the said polyethylene glycol, and the blend of components (A) and (B) is advantageously prepared at from 50 to 100"C in the presence of up to 20% by weight (on resin solids) of auxiliary organic solvents.

For use as binders in paints and varnishes, the carboxyl groups of the blend of components (A) and (B) are neutralised with bases such as amines and/or ammonia in an amount equivalent to an acid value of up to 20 mg KOH/g prior to emulsification in water.

Component (A) used in the aqueous emulsion, is an acrylic modified alkyd resin and preferably has the following specification. The ranges given for the content of polyethylene glycol (PEG) and of acrylic methacrylic acid, and the listed acid values and intrinsic viscosities are critical. The other parameters are listed in their preferred ranges and may be employed within wider limits.

Unsaturated oil fatty acids 25 - 50 % aromatic or cycloaliphatic monocarboxylic acids 0 - 20% aromatic and/or cycloaliphatic dicarboxylic acids 5 - 15 % polyethylene glycol (PEG) 7-13% (preferably 9 - 11 %) polyalcohols (besides PEG) 8 - 20 % acrylic acid/methacrylic acid 4-10% acrylic or vinyl monomers containing no other functional groups besides the double bond 10 - 26 % acid value 25 - 70 mg KOH/g hydroxyl value 30-100 mg KOH/g intrinsic viscosity 9 - 12 ml/g (chloroform, 20 C) The acrylic modified alkyd resins (A) used in the emulsions of the invention serve to emulsify the urethane alkyd (B) and also act as a dispersing aid for the pigments which may also be incorporated in the composition. In order to obtain good storage stability in the emulsions and paints, it is desirable that stabilising hydrophilic groups provided by the polyethylene glycol (PEG) are bound to the component (A) such that they are resistant to hydrolysis to the greatest possible degree. For this reason, the PEG is advantageously introduced according to a method described in Austrian Patent No.365.215.

In this method polyethylene glycol is reacted in a separate etherification reaction with double the equimollar amount of a monoepoxy fatty acid ester and the thus obtained PEG-modified fatty acid ester is then introduced into the alkyd resin.

Such monoepoxyfatty acid esters are products of the general formula

X being a saturated alkyl radical with from 2 to 8 C-atoms, Y being a saturated alkylene radical with from 7 to 11 C-atoms and Z being a saturated aliphatic, cycloaliphatic or aromatic hydrocarbon radical with from 1 to 10 C-atoms.

These compounds may be obtained through epoxidation of esters of monohydric alcohols with monohydric fatty acids. Suitable examples are lauric acid, myristic acid, palmitic acid, oleic acid, or erucic acid. Particularly preferred are epoxidised products of oleic acid esters. The alcohol component is a monohydric saturated aliphatic, cycloaliphatic or aromatic alcohol with from 1 - 10 C-atoms.

Epoxidisation may be carried out according to known methods, e.g. with hydrogen peroxide and formic acid. The product according to the general formula contains one epoxy group per molecule and has to be present to a level of at least 75 % in the technical blend. Products of this kind are available and are named n-alkyl- or i-alkyl epoxy fatty acid esters in the respective data sheets.

Suitable polyethylene glycols are products with an average molecular weight of from 500 to 5000. They are advantageously etherified in a mole ratio of from 1:1.7 to 1: 2.1 with the epoxy compound in the presence of catalysts. Preferably the PEG molecule is bound to the fatty acid ester at both ends by ether linkages. This may be achieved by dewatering the PEG by vacuum distillation with an entraining agent, followed by the addition of the catalyst and heating to 100 to 1 50"C. Then, during several hours, the epoxy compound is added and the temperature held until the epoxy value has fallen to below 0.01. Suitable catalysts are e.g.

sulphuric acid, perchloric acid, aluminium chloride and borotrifluoride.

The etherification product thus obtained (polyethylene glycol diether) is then reesterified at about 250"C in the presence of suitable catalysts (e.g. litharge or calcium hydroxide) with the other components used in the production of component (A) with separation of the monohydric alcohol used in the reaction with the mono-epoxy compound. The mono-hydric alcohol is quantitatively stripped through vacuum distillation.

In the interests of resistance to hydrolysis, at least 80 %, preferably at least 90 % of the carboxyl groups of the acrylic modified alkyd resin (A) should arise from copolymerised acrylic or methacrylic acid. The preferred method for producing such a component is the one cited in European Patent Application 00 29 145 (Austrian Patent Application A 7335/79). In this method a blend of acrylates, vinyl compounds and methacrylic acid is copolymerised with part of the desired oil fatty acids and the copolymer is then esterified with the other components of the alkyd resin. Resin formulation and production methods are selected such that at the end of the reaction substantially only the sterically hindered tertiary carboxy groups stemming from the methacrylic acid remain free and later on serve for stabilising the emulsion.This method has the advantage that products with good drying characteristics are obtained, since only part of the fatty acids are reduced in drying capacity through copolymerisation. Owing to the described constitution of the acrylic modified alkyds there are-large hydrophobic molecule segments between the hydrophilic groups (PEG-chains and carboxyl groups) (which are responsible for the stability of the emulsion) and the ester linkages; the hydrophobic segments substantially retard the attack of water and thus the hydrolytic separation of the sensitive linkages.

When selecting the raw materials it is important to chose PEG of an appropriate average molecular weight and appropriate acrylic and vinyl monomers carrying no other functional group besides the double bond.

The best stability of the emulsion is attained by using esters of acrylic and methacrylic acids with long-chain alcohols, such as 2-ethyl-hexylacrylate. These monomers, however, exert a highly plasticising effect and thus adversely effect drying and film hardness. It is therefore necessary to adjust the characteristics of the product to the required tolerances by judiciously selecting appropriate monomers. Good all-round performance can be achieved e.g. with blends of isobutyl-methacrylate and vinyltoluene. Selection of the other raw materials is less critical. Suitable unsaturated (drying) fatty acids are those with an iodine number of over 125. Aromatic and cycloaliphatic monocarboxylic acids, dicarboxylic acids and polyalcohols may be selected by a person skilled in the art according to normal criteria.

The acrylic modified alkyd resins (A) may be prepared according to methods known from the literature; however, it should be ensured that the required criteria, i.e. the presence of acrylic acid carboxy groups are fulfilled. For example, first a PEG-modified alkyd resin with an acid value of below 5 mg KOH/g may be prepared and this subsequently copolymerised with a blend of acrylates, vinyl compounds and the required quantity of acrylic acid and/or methacrylic acid to give the required final acid value.

The urethane modified alkyd resins which are used as component (B) in the emulsions of the invention are water-insoluble resins, in principle known to those skilled in the art as solvent-dissolved paint binders. In terms of weight they form the main portion of resin solids of the emulsions of the invention and are thus mainly responsible for film formation and film performance. In their formulation main attention should be given to achieving rapid drying and good oxidativecrosslinking of the film.

The urethane modified alkyd resins used for the emsulsions of the invention advantageously have the following characteristics: unsaturated oil fatty acids 45 - 65 % aromatic or cycloaliphatic monocarboxylic acids 0 - 20 % polyalcohols 15-25% dicarboxylic acids 8 - 16 % diisocyanates 8 - 25 % amine value 3 - 25 (preferably 5 - 15) mg KOH/g acid value below 5 mg KOH/g hydroxyl value 20 - 80 mg KOH/g intrinsic viscosity 8 - 16 ml/g (chloroform, 20) The given range concerning intrinsic viscosity is critical for the emulsions of the invention. The ranges for the other parameters are the preferred ones and may be varied within wide limits.

Suitable unsaturated fatty acids for use in preparing component (B) are those with isolated and conjugated double bonds and having an iodine number of over 125. Examples are the fatty acids of soya oil, safflower oil, linseed oil, tall oil and dehydrated castor oil as well as tung oil. The fatty acids may be used as such or as glyceride oils or synthetically produced polyol esters. Selection of the aromatic or cycloaliphatic monocarboxylic acids, of the polyalcohols and of the dicarboxylic acids is not critical and may be made at the discretion of the person skilled in the art according to the desired properties and specifications of the final product.

Suitable diisocyanates for achieving the desired drying speed and film hardness are for example aromatic products such as 4,4'-diphenylmethane diisocyanate and toluene diisocyanate. Preferred is a technical blend of 80 % of 2,4- and 20% of 2,6-toluene diisocyanate.

The preparation of the urethane modified alkyd (B) may be carried out in two steps according to the following method: First, according to normal methods, a low molecular weight hydroxy-rich alkyd resin is produced. Then, an inert solvent is added, and, at from 40 to 60"C, the diisocyanate is charged. Then the temperature is raised to 90 to 1 1 OOC and held, until the NCO-content has fallen to below 0.1 % and the desired intrinsic viscosity is attained. In some cases small quantities of low molecular weight monoalcohols like methanol or ethanol may be used to regulate the molecular weight and the content of urethane groups.

These alcohols are added to the batch prior to charging the diisocyanates.

In the preparation of the emulsions the acrylic modified alkyd (A) and the urethane modified alkyd (B) are blended in the desired ratio. Should the products contain water-insoluble solvents owing to the method of production, these may be vacuum-stripped with caution. Then, the auxiliary solvent, at a level of up to 20 % on resin solids, is stirred in. Suitable auxiliary solvents are alcohols and their ethers, the preferred solvent being ethyleneglycolmonobutylether. For partial neutralisation of the carboxy groups amines and/or ammonia are added, the preferred ones being triethylamine (TEA) and dimethylethanolamine (DMEA) or blends thereof, optionally with other amines. Suitable amines of this type are known to those skilled in the art.

It is an advantage of the emulsions of the invention that only low levels of amine are required for neutralisation, equivalent to up to 20 acid value units.

Finally, in order to prepare the emulsions, water is stirred in vigorously preferably at a temperature of between 40 and 60"C in the course of 1 to 3 hours. The resulting milky emulsions, transparent in thin layers, have good storage stability. They may be processed without difficulty to yield quick drying primers and finishes. They may be applied pigmented or unpigmented, optionally with the addition of normal paint additives, by brushing, dipping, spraying, flow coating, etc. Drying may be effected at room temperature, but on industrial coating lines force-drying is preferred. With the addition of heat-reactive crosslinkers the emulsions of the invention may also be cured at higher temperatures, e.g. at from 100 - 130"C.

The following non-limiting Examples illustrate the invention. Parts and percentages are by weight unless otherwise stated. The cited intrinsic viscosities were measured in chloroform (CHF) or dimethylformamide (DMF) at 20"C and are given in ml/g.

I) Preparation of the polyethylene glycol diethers: According to Table 1 the polyethyleneglycol diethers (PE 1 and 2) are prepared in the following way: In order to separate off water, the polyethylene glycol is mixed with 10 % of toluene, heated to 120"C and held under vacuum until nothing distils off. Then the temperature is reduced to 11 00C and BF3-diethylether complex added. In the course of 5 hours the epoxy fatty acid ester is added continuously at 110"C and held until the epoxy value has fallen to below 0.01. Then using a small quantity oftoluene as entraining agent, the BF3-complex catalyst is vacuum-stripped to a great extent.

TABLE 1 PE 1 2 PEG 1500 750 PEG 300 - 750 PEG 600 - 150 BF3-diethylethercomplex 5 5.7 EPF 1 380 EPF2 - 380 PEG . polyethylene glycol (figures indicate average molecular weight) EPF 1 : according to producer's data an n-alkyl epoxystearate with a molecular weight of 377 and a content of epoxy oxygen of 4.5 % EPF 2 : according to producer's data an i-alkyl-epoxy stearate with a molecular weight of 380 and an epoxy oxygen content of 4.5 %.

II) Preparation of fatty acid acrylic copolymers: Constitution and constants of the copolymers are listed in Table 2.

TABLE 2: Copolymers C1 C2 C3 C4 C5 C6 linseed oil fatty acid 44.5 37.5 37.5 37.5 20 15 safflower oil fatty acid 17.5 15 dehydrated castor oil fatty acid 7.5 isobutylmethacrylate 30.5 12.5 44 34.5 30 n-butylmethacrylate 25 n-butylacrylate 8 methyl methacrylate 5.5 vinyltoluene 5.5 31 6 10 styrol 6 methacrylic acid 19.5 19 18.5 22 22 18.5 acid value mgKOH/g 207 192 186 209 207 190 intrinsic viscosity (DMF) 5.3 5.8 5.5 6.0 5.9 6.2 The polymerisation is carried out in a xylene solution at 135 - 140"C with a theoretical batch concentration of 90 %. Two thirds of the vacuum-dewatered fatty acid are charged with half of the xylene and heated to reaction temperature.Then, within 6 to 8 hours, the monomer blend and the blend consisting of the remaining fatty acid and xylene and of the peroxide initiator is added continuously. The peroxide initiator is a blend of 3 parts of tert.butylperbenzoate and 1 part of 50 % dibenzoyl peroxide calculated on 100 parts of final product.

After addition of all components is complete, the batch is held at 135 - 140"C until a determination of the content of non-volatile matter shows a conversion of at least 95%. Should the reaction be too slow, more tert.butylperbenzoate may be added.

III) Preparation ofthe acrylic modified alkyd resins (Component A) Constitution and constants of these "emulsifying resins", abbreviated by "ER" in the following, are listed in Table 3.

TABLE 3 ER1 ER2 ER3 ER4 part 1 PE 120 - 120 120 PE2 - 115 - pentaerythritol 110 110 110 110 para-tert.butylbenzoic acid 120 120 60 120 linseed oil fatty acid 20 20 - tall oil fatty acid - - 115 20 calcium octoate (4 % Ca) 0.5 0.5 0.5 0.5 zinc octoate (8 % Zn) 0.25 0.25 0.25 0.25 part 2 dehydrated castor oil fatty acid 40 - - 40 linseed oil fatty acid 30 20 - tall oil fatty acid - - - 30 conjugated linseed oil fatty acid (50 % conjugated) - 50 70 phthalic acid anhydride 50 55 65 50 tetrahydrophthalic acid anhydride 13 8 - 13 part3 copolymer C 1" - - - 380 copolymer C 2+ - - 270 copolymer C 3+) 250 - - copolymer C 4+) - 310 - linseed oil fatty acid 60 - 65 PEG (%) 10.2 10.2 9.5 9.4 methacrylic acid (%) 5.9 8.8 6.1 8.8 acid value (mg KOH/g) 33 44 41 45 intrinsic viscosity (CHF) 11.2 11.7 9.8 10.6 + The figures refer to 100 % resin solids.

For the preparation of the emulsifier resins the following method is used: Part 1 is held at 250"C, until practically all the monohydric alcohol of the PEG-modified fatty acid ester ("PE") is set free through re-esterification and distilled off. This takes from about 90 minutes to 3 hours. Then the batch is cooled to 200"C and part 2 is added. With azeotropic distillation, using xylene, the products are esterified to an acid value of below 5 mg KOH/g. Part 3 is added and esterification is carried on, until the final values are attained.

In the final phase vacuum is used to nearly quantitatively strip the xylene used as entraining agent.

The method used for preparing resins ER 1 to ER 4 is the preferred one because the products have good drying characteristics and excellent emulsifying effect. The resins may also be prepared according to normally used methods, i.e. by copolymerising a low molecular weight alkyd resin intermediate with the monomer blend. This method is used for preparing resin ER 5: 141 parts pentaerythritol, 154 parts PE 1, 154 parts p-tert.butylbenzoic acid and 26 parts linseed oil fatty acid are reesterified at 250"C in the presence of 0.65 parts of calcium octoate (4 %) and 0.32 parts of zinc octoate (8 %), reaction water and about 15 parts of a water-insoluble distillate being produced.Then, at 220"C, 290 parts of linseed oil fatty acid, 64 parts phthalic anhydride and 17 parts tetrahydrophthalic anhydride are added and the esterification carried on by azeotropic distillation (xylene) to an acid value of below 5 mg KOH/g. The product is diluted with xylene to 85 % solids.

82.5 parts of the 85 % resin solution are heated to 132"C. During the course of 6 hours a blend of 11.8 parts of the alkyd resin intermediate/85 %, 11 parts isobutylmethacrylate, 6 parts acrylic acid and 3 parts vinyltoluene and a solution of 0.8 parts di-tert.butylperoxide in 18.2 parts of xylene are added at 132"C. As soon as a solids content of more than 74.5 % is attained, the xylene and the unreacted monomers are vacuum-stripped at from 140 to 1 600C. The temperature is held until an intrinsic viscosity (CHF) of about 10 ml/g is attained.The product has a PEG-content of 10.3 % and a content of acrylic acid of 6 %, an acid value of 36 mg KOH/g and an intrinsic viscosity of 9.9 (CHF).

Preparation of ER 6:154 parts of PE 1, 141 Parts pentaerythritol, 154 parts p-tert.benzoic acid, 26 parts safflower oil fatty acids are re-esterified as described for ER 1 - ER 4 in the presence of 0.65 parts of calcium octoate and 0.32 parts zinc octoate. Then, at 1900C, 320 parts copolymer C5, 120 parts safflower oil fatty acid, 50 parts of a conjugated fatty acid (degree of conjugation 50 %, iodine value 125 - 135; (Conjuvandol 50)), 64 parts phthalic an hydride and 17 parts tetrahydrophthalic anhydride are added and the batch is esterified under azeotropic distillation (xylene) and, towards the end of the reaction, under vacuum, until the desired acid value and intrinsic viscosity is attained.

The intermediate has a PEG content of 10.4 %, a content of methacrylic acid of 7.1 %, an acid value of 39 mg KOH/g and an intrinsic viscosity (CHF) of 10.6 ml/g.

Preparation ofER 7: 141 parts pentaerythritol, 100 parts p-tert.butylbenzoic acid, 20 parts benzoic acid and 160 parts sunflower oil fatty acid are held at 250"C for 2 hours under inert gas, then 90 parts of the conjugated fatty acid used in ER 6, 50 parts sunflower oil fatty acid and 100 parts of a polyethylene glycol with an average molecular weight of about 1500,75 parts phthalic anhydride and 30 parts tetrahydrophthalic anhydride, 320 parts of copolymer C6 are added and the batch is esterified as described for ER 6. The intermediate has a PEG-content of 9.8, a content of methacrylic acid of 5.9, an acid value of 34 mg KOH/g and an intrinsic viscosity (CHF) of 10.3 ml/g.

IV) Preparation ofthe urethane modified alkyd resins (UR) Composition and data of the urethane modified alkyd resins are listed in Table 4.

TABLE 4 UR1 UR2 UR3 UR4 UR5 UR6 partl tall oil fatty acid - 380 280 380 - 300 Conjuvandol50+) - - 100 - - safflower oil 300 - - - - - safflower oil fatty acid - - - - 650 linseed oil fatty acid - - - - - 150 dehydrated castor oil 120 - - - - - pentaerythritol 86 47 104 47 204 47 trimethylolpropane 9 - - - - - glycerol - 106 67 106 - sorbitol (70 %) 300 benzoic acid 8 - - - - - p-tert.butylbezoic acid - - 60 - - calciumoctoate(4%Ca) 1- - - - - lead octoate (10 % Pb) 0.5 - - - - part 2 phthalic acid anhydride 90 100 100 85 100 100 part3 trimellitic acid anhydride - - - 20 part4 methanol 2.5 4.6 5.0 4.5 10.5 6.9 part 5 toluylenediisocyanate (TDI++)) 82 140 135 131 188 137 contentofTDI (%) 11.9 18.6 16.4 17.8 7.1 15.5 acidvalue(mgKOH/g) 1.5 0.8 1.2 10.2 0.6 1.3 intrinsic viscosity (CHF) 13.6 10.8 10.4 9.9 10.3 12.5 resin solids (solvent: 91 % 91 % 91 % 91 % 91 % 91 % ethyleneglycolmonobutyl ether=EB + isomerised technical linoleic oil fatty acid with about 50% conjugated linoleic acid ++) 80 % 2,4 and 20 % 2,6-isomers.

The urethane modified alkyd resins are prepared according to the following method: First a low molecular alkyd resin with an acid value of below 2 mg KOH/g is prepared from parts 1 and 2 by esterification at 220 C.

In the case of UR 1 the oils used in part 1 prior to addition of part 2 have to be reesterified with the polyalcohols through heating of part 1 to 2500C, until a sample, 1: 6 diluted with ethanol, is clearly soluble at 20"C.

In the case of UR 4, after reaching an acid value of below 2 mg KOH/g, the temperature is reduced to 1 60"C and part 3 is added. Atemperature of 160 to 1700C is held until an acid value of from 12 to 13 mg KOH/g is reached; the esterification is enhanced towards the end by application of vacuum.

The reaction of the alkyd intermediate thus obtained with the diisocyanate and the methanol is carried out in a 60% solution in toluene. The alkyd resin intermediates are blended with methanol and heated to 50"C.

Then TDI is added and the solution heated to 100 C. The temperature is held until the NCO-content has fallen below 0.1 % and the desired intrinsic viscosity is attained. If necessary, small increments of TDI are added.

Then the toluene is vacuum-stripped to the extent that the resin has a solids content of about 80 %. At this stage 10 parts of ethyleneglycolmonobutyl-ether are added for each 100 parts of resin solids. Vacuumstripping of toluene is continued, until it is completely removed. (Solids content: 91 %).

Examples 1 - 7: Composition and constants of the emulsions of Examples 1 - 7 are listed in Table 5.

TABLE 5 Example 1 2 3 4 5 6 7 ER1 1) 40 - - - - - 2 1) - - 30 - - - 3 1) - - - 40 - - 4 1) - - - - 35 - 5 1) - 40 - - - - - 6 1) - - - - - 40 7 1) - - - - - - 40 UR1 2) - 66 - - - - 2 2) 66 - - - 71.5 - 3 2) - - - 66 - - 4 2) - - 77 - - - 5 2) - - - - - 66 6 2) - - - - - - 66 EB 9 9 8 9 8.5 9 9 TEA 2a) 1.59 1.73 2.34 1.95 1.87 1.93 1.93 DMEA 0.7 0.76 1.03 0.86 0.83 0.85 0.85 H2O 105 105 132 104 104 104 104 solids content % 45 45 40 45 45 45 45 pH-value 9.7 9.7 9.9 9.8 9.6 9.6 9.9 viscosity (Pa.s) 3) 2.6 2.8 7.4 6.9 3.3 4.8 5.5 content of EB (%) 6.75 6.75 6.0 6.75 6.75 6.75 6.75 amine content (%) 1.03 1.12 1.35 1.26 1.22 1.26 1.26 ABEL-PENSKY flash point over 65"C 1) 100% 2) 91 % 2 a) triethylamine 3) measured with BROOKFIELD RVT, spindle 6, 100 rpm, 20"C The emulsions are prepared in the following way: Emulsifier resin, urethane modified alkyd and EB are mixed well at 800C for 60 minutes. Then the temperature is reduced to 60 C and the amine blend is stirred in.

After 30 minutes, the temperature is further reduced to 50 C and addition of water is started. The water is added within 60 to 90 minutes with vigorous stirring, the temperature being held at between 40 to 50 C. Then stirring is continued for further 30 minutes.

Evaluation ofthe emulsions according to examples 1-7 1. Test for storage stability To reduce testing time, the emulsions are diluted to 30 % and stored at 70"C. There is no exact way of concluding the storage stability under normal conditions from these results; experience, however, shows that with a storage stability of 4 days under these conditions the emulsions will have a minimum storage stability of 6 months under normal conditions. The results are listed in Table 6.

2. Test of white enamels The emulsions are mixed with 2 % of a water tolerant drier blend 4) and 1 % of an antiskinning agent (on resin solids) and are diluted to 35 % with deionised water. Then they are pigmented with titanium dioxide 5) in a "Red Devil" paint shaker in a pigment/binder ratio of0.8:1. The paints are applied to glass plates and evaluated for drying, gloss and water resistance; dry film thickness 30 calm (results in Table 6).

TABLE 6 Example 1 2 3 4 5 6 7 storage stability of the emulsion (1 week/70) i.O.6 i.O. i.O. i,O. i.O. i.O. A, LR drying a) touch-dry(min) 25 60 25 20 25 25 30 b)tack-free(min) 60 135 55 40 60 55 60 c) through-dry (hours) 5 6 3.5 3.5 4 5 4 gloss7) 75 71 71 65 73 72 78 water resistance8 all products show slight swelling; they regenerate within a short time; gloss is not lost 4) HYDRO-CURE , MOONEY, USA (contains 5% Co) 5) RCR3,TioxideLtd.,UK 6) i.O. = in order 7) measured with Gonioreflektometer "GR-Comp" (Paar, Austria) measuring angle 60 , % to standard.

8) 24 hours water soak at 20"C, after 7 days of drying at room temperature.

3. Test ofantiocorrosion primers based on the emulsions of the invention 222 parts of the emulsion according to example 1,45 %, are milled in normal way with 50 parts red iron oxide, 50 parts lead silico-chromate, 70 parts baryte and 30 parts of talcum. They are mixed with 2 parts of Hydro-Cure w (see above), 1 part of an antiskinning agent, 1 part of an antisettling agent and 1 part of a defoamer and diluted with water to a viscosity of 4 mPa.s (ca.63 solids content) using a rotothinner. The pH-vaXue is adjusted with TEA to 9.0 - 9.5.

On storage for 4 weeks at 40"C, the paint does not change except for a slight precipitation which can easily be stirred up. Drying speed fortouch-dry/tack4ree/through-dry; 20 min./30 - 40 mind2 - 3 hours. On salt spray test (ASTM B 117/64) after 120 hours, films cured at room temperature for 7 days, show slight creep rust only at the cross incision. Peel-off at cross incision: 2 - 3 mm.

Claims (4)

1. An alkyd resin composition water-emulsifiable upon neutralisation with bases comprising (A) 25-45% by weight of an alkyd resin based on drying fatty acids modified with 4 to 10% by weight of acrylic and/or methacrylic acid and 7 to 13% by weight of a polyethylene glycol having a molecuiar weight of from 500 to 5000, the resin having an acid value of from 25 to 70 mg KOH/g and an intrinsic viscosity of from 9 to 12 ml/g (measured in chloroform at200C); and (B) 55-75% by weight of a urethane modified air drying alkyd resin having an intrinsic viscosity of from 8 to 16 ml/g (measured in chloroform at 20 C).

2. An alkyd resin composition as claimed in claim 1 in which the alkyd resin component (A) is modified with 9 to 11% by weight of the said polyethylene glycol.

3. An alkyd resin composition as claimed in claim 1 or claim 2 additionally comprising up to 20% by weight (on resin solids) of auxiliary organic solvents.

4. An alkyd resin composition as claimed in any one of claims 1 to 3 in which the blend of components (A) and (B) is proposed at a temperature of from 50 to 100 C.

4. An alkyd resin composition as claimed in any one of claims 1 to 3 in which the blend of components (A) and (B) is prepared at a temperature of from 5 to 1000C.

5. An alkyd resin composition as claimed in any one of claims 1 to 4 in which the alkyd resin component (A) contains from 25 to 50% by weight of unsaturated oil fatty acids.

6. An alkyd resin composition as claimed in any one of claims 1 to 5 in which the alkyd resin component (A) contains from 10 to 26% by weight of acrylic or vinyl monomers containing no other reactive functional groups besides the double bond.

7. An alkyd resin composition as claimed in any one of claims 1 to 6 in which the polyethylene glycol is attached to the molecule of alkyd resin component (A) via ether linkages.

8. An alkyd resin composition as claimed in any one of claims 1 to 7 in which the carboxyl groups of alkyd resin component (A) comprise at least 80% acrylic or methacrylic acid groups.

9. An alkyd resin composition as claimed in any one of claims 1 to 8 in which the carboxyl groups of alkyd resin component (A) are introduced by means of esterification of copolymers produced in a separate step by copolymerisation of a blend of drying oil fatty acids, methacrylic acid and vinyl and/or acrylic compounds containing no other functional groups besides the double bond.

10. An alkyd resin composition as claimed in any one of claims 1 to 9 in which the urethane modified alkyd resins of component (B) have a content of unsaturated oil fatty acids of from 45 to 65% by weight.

11. Alkyd resin compositions water-emulsifiable upon neutralisation with bases substantially as herein described.

12. Alkyd resin compositions water-emulsifiable upon neutralisation with bases substantially as herein described in any one of the Examples.

13. Water-emulsifiable alkyd resin compositions comprising an alkyd resin composition as claimed in any one of claims 1 to 12 neutralised with base.

14. Water emulsifiable alkyd resin compositions as claimed in claim 13 neutralised with base(s) selected from amines and/or ammonia.

15. Water emulsifiable alkyd resin compositions as claimed in claim 13 or claim 14 wherein the amount of base used for neutralisation is equivalent to an acid value of not more than 20 mg KOH/g.

16. Water emulsifiable alkyd resin compositions substantially as herein described.

17. Water emulsifiable alkyd resin compositions substantially as herein described in any one of the Examples.

18. Aqueous alkyd resin emulsions comprising an emulsifiable alkyd resin composition as claimed in any one of claims 13 to 17 emulsified in water.

19. Aqueous alkyd resin emulsions substantially as herein described.

20. Aqueous alkyd resin emulsions substantially as herein described in any one of the Examples.

21. Aqueous alkyd resin emulsions as claimed in any one of claims 18 to 20 for use as binders for paints and varnishes.

22. A process for the preparation of an aqueous alkyd resin emulsion which comprises emulsifying in water an alkyd resin composition as claimed in any one of claims 13 to 17.

23. A process for the preparation of an aqueous alkyd resin emulsion substantially as herein described.

24. A process for the preparation of an aqueous alkyd resin emulsion substantially as herein described in any one of the Examples.

25. An aqueous alkyd resin emulsion whenever prepared by a process as claimed in any one of claims 22 -24.

26. A paint or varnish comprising an aqueous alkyd resin emulsion as claimed in any one of claims 18 to 21 and 25.

27. A paint or varnish as claimed in claim 26 additionally comprising one or more pigments and/or conventional additives.

28. A paint or varnish comprising an aqueous alkyd resin emulsion as defined in claim 18 substantially as herein described.

29. A paint or varnish comprising an aqueous alkyd resin emulsion as defined in claim 18 substantially as herein described in any one of the Examples.

New claims or amendments to claims filed on 20th September 1982 Superseded claims 4 New or amended claims: