WO1997019120A1

WO1997019120A1 - Water-dispersible unsaturated polyurethane

Info

Publication number: WO1997019120A1
Application number: PCT/EP1996/005156
Authority: WO
Inventors: Roelof Buter; Norbert Johan Coenjaarts
Original assignee: Akzo Nobel N.V.
Priority date: 1995-11-21
Filing date: 1996-11-21
Publication date: 1997-05-29

Abstract

A water-dispersible unsaturated polyurethane comprising pendant unsaturated alkyl groups, pendant sulphonic acid salt groups and pendant alkoxy polyoxyalkylene groups is described. The sulphonic acid salt groups and alkoxy polyoxyalkylene groups are present in amounts at least sufficient to render the unsaturated polyurethane water dispersible. The unsaturated polyurethane is especially suited for dispersing alkyds in water. Also disclosed is a composite latex comprising an aqueous alkyd dispersion and monoethylenically unsaturated monomers and a pigment dispersion comprising a pigment or pigment paste and the unsaturated polyurethane.

Description

WATER-DISPERSIBLE UNSATURATED POLYURETHANE

The invention pertains to a water-dispersible unsaturated polyurethane comprising pendant unsaturated alkyl groups, pendant sulphonic acid salt groups, and polyoxyalkylene groups, said sulphonic acid salt groups and said polyoxyalkylene groups being present in amounts at least sufficient to render said unsaturated polyurethane water dispersible

Such an unsaturated polyurethane is known from European patent application EP-A-0613 914 The unsaturated polyurethane disclosed in that document comprises ionic groups, unsaturated alkyl groups, and polyoxyalkylene groups built into the polyurethane main chain

It has now been found that an unsaturated polyurethane having certain pendant groups permits efficient dispersion, suspension, emulsion, etc in water of hydrophobic polymers and pigments

The invention is a water-dispersible unsaturated polyurethane of the above- mentioned type characterised in that the polyoxyalkylene groups are pendant alkoxy polyoxyalkylene groups

In a particular embodiment, the unsaturated polyurethane according to the invention is of the above-disclosed type compnsing a) 10-40 wt %, preferably 15-20 wt %, C1-C4 alkoxy polyoxyalkylene groups, b) 0,1-0,5 meq. per gram, preferably 0,2-0,35 meq per gram, alkaii metal salt of sulphonic acid, and c) 10-35 wt %, preferably 20-30 wt.%, unsaturated, preferably polyunsaturated, alkyl groups European patent application EP-A-0 309 114 discloses a non-ionic polyurethane resin having pendant polyoxyethylene chains and, optionally, free acid groups Sulphonic acid groups or salts thereof are not disclosed

EP-A-0013 112 discloses an aqueous emulsion comprising an organic isocyanate and a surfactant The surfactant is a polyurethane dispersing resin with pendant alkoxy polyoxyethylene groups and an isocyanate reactive compound having, optionally, carboxylic acid groups Sulphonic acid groups or salts thereof are not mentioned

The sulphonic acid salt groups and the alkoxy polyoxyalkylene groups present in the unsaturated polyurethane of the current invention need to be present in amounts at least sufficient to render the unsaturated polyurethane water dispersible The necessary amounts will vary according factors such as, for non-limiting example, the specific unsaturated polyurethane, the use to be made of the unsaturated polyurethane, the aqueous system, other compounds present, etc These amounts are readily determined by a skilled artisan based on, for non-limiting example, the character of the unsaturated polyurethane and the further teachings found herein

The unsaturated polyurethane of the current invention can be prepared, for example, by reacting diisocyanate with a compound containing alkoxy polyoxyalkylene groups and two isocyanate reactive groups, a compound containing ionic groups and two isocyanate reactive groups, and a compound containing unsaturated alkyl groups and one isocyanate reactive group or a compound which is a reaction product of an unsaturated fatty acid and a mono-epoxide Non-limiting examples of suitable compounds for use in incorporating the C1- C4 alkoxy polyoxyalkylene groups into the unsaturated polyurethane include methoxy polyethylene glycols, polyether-1 ,3-propanedιols, such as Tegomer^® D-3123 (PO/EO = 15/85, Mn = 1180), Tegomer^® D-3409 (PO/EO = 0/100, Mn = 2240), and Tegomer^® D-3403 (PO/EO = 0/100, Mn = 1180) (Tegomer^® products available from Goldschmidt AG, Germany) In addition, reaction products of 1 or 2 moles of mono epoxide and polyoxyalkylene amines can be used e g , methoxy polyoxyethylene/polyoxypropylene amines, which are available from Huntsman Corporation, Zaventem, Belgium under the trade designation Jeffamine^® such as Jeffamine^® M-1000 (PO/EO = 3/19, Mn = 1100) and Jeffamine^® M-2070 (PO/EO = 10/32, Mn = 2200) It is preferred to employ alkoxy polyoxyalkylene groups having an average molecular weight of 500-3000

Suitable compounds for incorporating the sulphonic acid salt groups into the unsaturated polyurethane include alkaii metal-, particularly Na-, K-, and Li-, sulphosuccinates A non-limiting method of preparing such sulphosuccmates is a two step preparation process wherein 1) fumaric or maleic acid is converted into a diester diol with the aid of a mono-epoxide

o o

HO- :C- -OH + 2 H₂C A C R i

H H H

R 0 O

HO ^■cC I — cC — oO — I cCI — cC= = = CC — — I cCI O C C OH

H H₂ H H H₂ H wherein R is selected from hydrogen or a C_1- o alkyl group, and 2) the diester diol is reacted with, e g , NaHSO₃, to provide a compound having the following structure o R

H

HO C C O C C C C O C C OH

H H₂ H₂ I H H

S0₃ ^" Na ⁺

In addition, reaction products of 1 or 2 moles of mono epoxide and 1 mole of an alkaii metal salt, preferably a Na-, K- or Li-salt, of an ammosulphonic acid compound such as ammo ethane sulphonic acid (tauπne) or HO-functional esters of 5-(Na-sulpho)-ιsophthalιc acid can be used. Suitable mono epoxides for use in the above-mentioned reactions include: propylene oxide, 1 ,2-epoxy- octane, and the glycidyl ester of a carboxylic acid according to the formula-

wherein R is an alkyl group having 4-40 carbon atoms, in particular the glycidyl ester of 1 ,1 -dimethyl heptane carboxylic acid (available as Cardura^® E 10 from Shell Chemicals) Another example of a compound suitable for use in incoφorating the sulphonic acid salt groups into the unsaturated polyurethane is the reaction product of 1 mole of NaHSO₃ and 1 mole of propoxylated butene-2-diol-1 ,4 (having about 2 to 6, preferably about 3 to 5 moles of propylene oxide).

Fatty alcohols and fatty amines can be used to incoφorate the unsaturated alkyl groups into the unsaturated polyurethane. Preferred are polyunsaturated mono alcohols and mono amines. Non-limiting examples of suitable fatty alcohols are: oleyl alcohol, linoleic alcohol, iinolenic alcohol, linoleyl alcohol, and mixtures thereof. Non-limiting examples of fatty amines are oleyl amine, linoleic amine, liπolenic amine, linoleyl amine, the commercially available Genamin^® from Hoechst, and mixtures thereof

The reaction products of an unsaturated fatty acid and a mono epoxide can also be used to incorporate unsaturated alkyl groups into the unsaturated polyurethane according to the current invention Polyunsaturated fatty acids are preferred Non-limiting examples of fatty acids which can be used are linseed oil fatty acid, sunflower otl fatty acid, soybean oil fatty acid, and other natural or synthetic unsaturated fatty acids Preferred mono epoxides are propylene oxide, 1 ,2-epoxy octane, and mono epoxides of the Cardura^® E- seπes from Shell Chemicals

The unsaturated polyurethane can be made using isocyanate-functional compounds Examples of isocyanates which can be used are aliphatic, cycloaliphatic or aromatic di- tn-, or tetraisocyanates which can be ethylenically unsaturated Especially suitable are dusocyanates Non-limiting examples of such dusocyanates are toluene diisocyanate, 4,4'-dιιsocyanato diphenyl methane, 1 ,6-diιsocyanatohexane, tetramethyl xylylene diisocyanate, isophorone diisocyanate (1-ιsocyanato-3,3,5-tπmethyl-5- isocyanatomethylcyclohexane)

If so desired, small amounts of diols can be added as chain extenders when preparing the unsaturated polyurethane, e g , polyester or polyether diols such as neopentyl glycol adipate or polypropylene glycol having an average Mw of 300-3000

When preparing the unsaturated polyurethane the ratio of the isocyanate groups of the diisocyanate to the hydroxyl groups (and optionally ammo groups) derived from the other compounds is typically about 09-1 1 1 , most preferably about 1 1 The unsaturated polyurethane can be prepared in one or several steps For instance, it is possible to first react the polar compounds such as those supplying the alkoxy polyoxyalkylene groups and sulphonic acid salt groups with the isocyanate functional compounds and then complete the reaction with the unsaturated alkyl supplying compounds Alternatively, all hydroxyl (and optionally amιne)-contaιnιng compounds are mixed before being reacted with the isocyanate functional compounds All hydroxyl (and optionally amine)- containing compounds can be premixed in the reactor at elevated temperature, divested of solvents, if any, by distilling off at reduced pressure, and then reacted with the isocyanate functional compounds The unsaturated polyurethane is preferably prepared in a dry atmosphere at a temperature of 50- 40°C, preferably 90-130°C.

If so desired, a catalyst can be employed, e g., an orgaπometal compound such as dibutyl tin diacetoacetate and -dilaurate, in a conventional amount of 0,01-0,1 wt.% Preferably, the preparation of the unsaturated polyurethane is carried out in bulk or with a small quantity of organic solvent (5-10 wt %) which is inert in relation to the isocyanate functional compound Optionally, after its preparation, the unsaturated polyurethane can be thinned with another organic solvent to a viscosity at which the resm will become processable

The unsaturated polyurethane of the current invention is particularly useful as an aid to the dispersion of hydrophobic polymers and pigments in water Non- limiting examples of hydrophobic polymers are polyesters, polyacrylates, polyurethanes, and, in particular, alkyd resms

The invention further pertains to aqueous alkyd dispersions comprising the unsaturated polyurethane according to the invention, and to the preparation of such dispersions Aqueous dispersions comprising about 5-25 wt % unsaturated polyurethane resm and about 95-75 wt % alkyd resin are particularly preferred

Preferably, the alkyd resin used has an oil length of about 40-90 and an acid number of about 0,5-15 mg KOH/g, preferably 5-10 mg KOH/g If so desired, the acid groups of the alkyd resm can be wholly or partially neutralised with a base, preferably an alkali metal base, most preferably NaOH, KOH or LiOH

Aqueous dispersions of alkyd resins, including conventional alkyd resms which generally have an oil length of about 40-90 and an acid number of about 5-10 mg KOH/g, can be emulsified in water with the aid of the unsaturated polyurethane resm, with the acid groups derived from the alkyd resιn(s) simultaneously being neutralised wholly or in part with a base such as NaOH, KOH or LiOH TO this end an alkyd resm is mixed with the unsaturated polyurethane in a ratio of about 75-95 wt %, preferably about 85-95 wt %, alkyd resin about 5-25 wt %, preferably about 5-15 wt %, unsaturated polyurethane, and a small quantity of Na-, K- or LiOH The particle size of such dispersions is typically about 50-800 nm, preferably about 100-500 nm

Next, the mixture of alkyd resm, unsaturated polyurethane, and base is heated to a temperature in the range of 100 to 150°C, optionally with (any) solvents present being distilled off under reduced pressure After the removal of (any) present solvents the mixture is cooled At a temperature of about 70 to 100°C, preferably of about 80 to 90°C, the addition of water is started, with vigorous stirring, over a period of 2-4 hours, with the temperature of the mixture gradually being lowered to ambient temperature A stable alkyd dispersion in water is obtained with a viscosity of 0,1-1 Pa s, preferably 0,2-05 Pa s The resulting aqueous alkyd dispersions generally have a solids content of about 40 to 70 wt %, preferably 50-60 wt % 8

In addition to the described inverse emulsification of a mixture of alkyd resin and the unsaturated polyurethane by adding water to the mixture, the mixture can also be dispersed in water directly In that case a mixture of alkyd resm and unsaturated polyurethane is preferably heated to a temperature in the range of about 60 to about 100°C This mixture is pumped into a reactor containing water, with vigorous stirring Optionally, a small quantity of base, preferably NaOH, KOH or LiOH, can be present in the water to neutralise any carboxylic acid groups of the alkyd resin present If so desired, special equipment can be employed in which a mixture of alkyd resm is dispersed in water with high shearing forces, for instance, a colloid mill

The invention also pertains to an aqueous polymer dispersion in which about 10-90 wt %, preferably about 30-70 wt %, of the solids content is derived from an alkyd dispersion according to the invention and about 90-10 wt %, preferably about 70-30 wt %, is derived from an addition polymer obtained by dispersion polymerisation in the presence of an alkyd dispersion according to the invention

A wide range of monoethylenically unsaturated monomers and mixtures thereof can be employed to prepare such an addition polymer, e g (cyclo)alkyl(meth)acrylates having 1-12 carbon atoms in the (cyclo)alkyl group, such as methyl(meth)acrylate, ethyl(meth)acrylate, proρyl(meth)acrylate, ιsopropyl(meth)acrylate, (ιso)butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate, ιsobornyl(meth)acrylate, dodecyl(meth)acrylate, and cyclohexyl(meth)acrylate; monovinyl aromatic compounds, such as styrene, vinyl toluene, α-methylstyrene, and vinyl naphthalene, other substituted (meth)acrylate compounds, such as (meth)acrylamιde, (meth)acrylonιtrιle, N- methylol(meth)acrylamιde, and N-alkyl(meth)acrylamιdes, and other mono- unsaturated compounds, such as vinyl chloride, vinyl acetate, and vinyl propionate In addition, small quantities can be used of (cyclo)alkyl esters of dicarboxylic acids having 1-12 carbon atoms in the (cyclo)alkyl group, such as dimethyl maleate, diethyl maleate, dipropyl maleate, dibutyl maleate, 2- ethylhexyl maleate, octyl maleate, isobornyl maleate, dodecyl maleate, and cyclohexyl maleate, diethyl fumarate, dibutyl fumarate, and 2-ethylhexyl fumarate, (meth)acrylates containing ether groups, such as 2- methoxyethyl(meth)acrylate, 2-ethoxyethyl(meth)acrylate, 3-methoxy- propyl(meth)acrylate, hydroxy(meth)acrylates, such as 2- hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 4- hydroxybutyl(meth)acrylate, 6-hydroxyhexyl(meth)acrylate, p- hydroxycyclohexyl(meth)acrylate and alkoxy denvates thereof, such as hydroxypolyethyieneglycol (meth)acrylate, and hydroxypolypropyleneglycol (meth)acrylate,

If so desired, anionic or non-ionic emulsifiers can be employed during the emulsion polymerisation Non-limiting examples of suitable anionic emulsifiers are potassium laurate, potassium stearate, potassium oleate, sodium decyl sulphate, sodium dodecyl sulphate, sodium dodecyl benzene sulphonate, and sodium rosinate Non-iimiting examples of non-ionic emulsifiers are linear and branched alkyl polyethylene glycol and alkylaryl polyethylene glycol, polypropylene glycol ethers and polypropylene thioethers, alkyl phenoxypoly(ethylenoxy)ethanols such as the adduct of 1 mole of nonylphenol to 5-12 moles of ethylene oxide, or the ammonium salt of the sulphate of this adduct During the emulsion polymerisation process use can be made of conventional radical initiators in the usual amounts Examples of suitable radical initiators are ammonium persulphate, sodium persulphate, potassium persulphate, bιs(2-ethylhexyl)peroxydιcarbonate, di-n-butyl peroxydicarbonate, t-butyl persulphate, t-butyl hydroperoxide, cumene hydroperoxide, dibenzoyl peroxide, diiauroyl peroxide, 2,2-azobιsιsobutyronιtπle, and 2,2-azobιs-2- methyl butyronitπle Reducing agents suitable for use in combination with, e g , a hydroperoxide include ascorbic acid, sodium sulphoxylate, sodium sulphoxylate formaldehyde, thiosulphites, disulphites, hydrosulphites, water- soluble amines, such as diethylene triamine, triethylene tetramine, tetraethyiene pentamine, N,N-dιmethyl ethanolamine, N,N-dιethyl ethanolamine, and reducing salts, such as cobalt sulphate, iron sulphate, nickel sulphate, and copper sulphate If so desired, a chain regulating agent can be employed, e g., n-octyl mercaptan, dodecyl mercaptan, and 3- mercaptopropionic acid

The dispersed polymer particles can be composed of a physical mixture of an addition polymer, such as a polyacrylate, and an alkyd. However, if graft polymerisation occurs during the emulsion polymerisation process, the alkyd resin can be partially combined with the addition polymer, giving dispersed polymer particles composed in part of block polymers and graft polymers of alkyd and addition polymers.

The thus produced composite latex has a solids content of about 30 to 55 wt.%, preferably of about 35 to 50 wt.%.

The aqueous alkyd dispersions and polymer dispersions according to the invention are preferably used to formulate coating compositions When used as such, the dispersions can contain a wide range of other additives common in the coatings industry, such as pigments, extenders, dispersing agents, thixotropy and rheology control agents, as well as siccatives. The group of siccatives is commonly held to include the metal soaps of alkaline-earth metals and heavy metals of monovalent carboxylic acids such as naphthenic acid, octanoic acid or 2-ethyl hexanoic acid. Primary active siccatives contain Co, Mn, Fe or Ce, supplementary siccatives can contain Pb, Ca, Zn, Ba or Zr They are conventionally used in an amount of about 0,01 to 0,5 wt %, calculated on the so ds content of the coating composition Other suitable siccatives include Co(ll)(acetylacetonate)₂ and Zr(IV)(acetylacetonate) If so desired, the siccatives can be co-dispersed with the alkyd and the unsaturated polyurethane

The coating compositions based on the disclosed alkyd dispersions can include special emulsifiers to obtain a spontaneous emulsion in water Siccatives which can be emulsified in water are commercially available An anti-skinning agent can be incoφorated into the coating compositions to ensure pot life Examples of anti-skinning agents are oxims, such as butyraldoxim and ethyl methyl ketoxim Favourable results are generally obtained when a quantity of about 0,01 to 1 wt %, calculated on the quantity of film-forming constituents, is employed for each of the siccatives as well as the anti-skinning agent

The coating compositions according to the invention can be applied onto any known substrate such as wood, synthetic materials, and metals Suitable application methods include rolling, spraying, sprinkling, dipping, and electrostatic spraying Of course it is also possible to apply the coating composition by simple brushing

The coating composition can be dried and cured under a variety of conditions, e g , at room temperature Accelerated curing can be accomplished by baking at elevated temperatures in the range of, e g , about 30 to 80°C typically over a period of 20 to 60 minutes The coating compositions according to the invention can be used as a primer or filler and also in clear and coloured paints.

The unsaturated polyurethane according to the invention is also highly suitable as a pigment dispersing agent Such a dispersing agent can be prepared without solvents, or there can be solvent removal through distillation under reduced pressure, followed by dispersion in water. Stable aqueous pigment pastes can be obtained by using preferably about 1-10 wt.% (on solids) of the unsaturated polyurethane in relation to the pigment. Each pigment can be dispersed in water with the unsaturated polyurethane, e.g , TiO₂, phthalocyanine, iron oxide, etc., or pigments can be mixed and the mixture dispersed.

The invention will be further illustrated with reference to the following non- limiting examples.

Experimental

The following examples disclose the preparation of a number of unsaturated polyurethanes and stable aqueous alkyd dispersions, as well as coating compositions prepared using the unsaturated polyurethane prepared according to the invention The properties of the dispersions are listed in the tables The average particle size of the dispersions in the examples was determined by dynamic light scattering, the dispersions being diluted to a solids content of about 0,1 wt % The viscosity was determined with a Brookfield viscometer (LV=4, 60 rpm) The solids content was determined in accordance with ASTM method 1644-59, after 30 minutes of heating at 140°C

As sulphonic acid salt containing compound, a reaction product of 1 mole of maleic acid, 2 moles of Cardura^® E 10, and 1 mole of NaHSO₃ (acid number<1 , Mw = 720, 70% in 1 -methoxypropanol-2) is used in the following examples The compound is further indicated as "NaHSO₃-compound"

Preparation of Unsaturated Polyurethane A

The following compounds were weighed into a 2 I reaction flask

194,7 g Tegomer^® D-3123,

344,6 g NaHSO₃-compound,

348,0 g Reaction product of an unsaturated fatty acid (having 65 wt % of conjungated linoleic acid) and propylene oxide (acid number<1 , Mw = 348), and

100,0 g o-xylene

The mixture was heated to about 130^βC, with the solvent present being distilled off under reduced pressure After cooling to about 50°C a mixture of 14

222 g of isophorone diisocyanate and 70 g of methylethyl ketone was added to the reaction mixture, after which the reaction mixture was kept at 120°C for 2 hours Dibutyl tin diacetate (5 or 6 drops) was added and the reaction was maintained at 120°C for 3 hours 1 -Methoxypropanol-2 (265,3 g) was added and the reactor contents were cooled to ambient temperature The prepared unsaturated polyurethane had a solids content of about 75 wt %

Preparation of Unsaturated Polyurethane B

The following compounds were weighed into a 2 I reaction flask

194,7 g Tegomer^® D-3123,

344,6 g NaHSO₃-compound,

541 ,0 g Reaction product of an unsaturated fatty acid (having 65 wt.% of conjungated linoleic acid) and Cardura^® E 10 (acid number<1 , Mw = 541 ), and

100,0 g o-xylene

Unsaturated Polyurethane B was prepared following the procedure for the preparation of Unsaturated Polyurethane A, except that 83,5 g of methylethyl ketone were added to the reaction mixture and on completion of the reaction as above the reactor contents were diluted with 316,3 g of 1 -methoxypropanol- 2 The prepared unsaturated polyurethane had a solids content of about 75 wt %

Preparation of Unsaturated Polyurethane C

The following compounds were weighed into a 2 I reaction flask 194,7 g Tegomer^® D-3403,

344.6 g NaHSO₃-compound,

100,0 g o-xylene

Unsaturated Polyurethane C was prepared following the procedure for the preparation of Unsaturated Polyurethane A, except that 70 g of methylethyl ketone were added to the reaction mixture and on completion of the reaction as above the reactor contents were diluted with 265,3 g of 1 -methoxypropanol- 2 The prepared unsaturated polyurethane had a solids content of about 75 wt %.

Preparation of Unsaturated Polyurethane D

The following compounds were weighed into a 2 I reaction flask:

194.7 g Tegomer^® D-3403, 344,6 g NaHSO₃-compound, 267,0 g Oleyl/linoleyl alcohol (available from Henkel under the trade designation HD-Ocenol 110/130), and 100,0 g o-xyleπe.

Unsaturated Polyurethane D was prepared following the procedure for the preparation of Unsaturated Polyurethane A, except that 64,3 g of methylethyl ketone were added to the reaction mixture and on completion of the reaction as above the reactor contents were diluted with 244 g of 1 -methoxypropanol-2. The prepared unsaturated polyurethane had a solids content of about 75 wt.% 16

Preparation of Unsaturated Polyurethane E

The preparation of Unsaturated Polyurethane D was repeated, except that oleyl alcohol (available from Henkel under the trade designation HD-Ocenol^® 90/95) was employed instead of HD-Ocenol 110/130

Preparation of Unsaturated Polyurethane F

The following compounds were weighed into a 2 I reaction flask 118,0 g Tegomer^® D-3403,

411 ,5 g NaHSO₃-compound,

267,0 g Oleyl alcohol (available from Henkel under the trade designation

HD-Ocenol^® 90/95), and 100,0 g o-xylene

Unsaturated Polyurethane F was prepared following the procedure for the preparation of Unsaturated Polyurethane A, except that 62,2 g of methylethyl ketone were added to the reaction mixture and on completion of the reaction as above the reactor contents were diluted with 236 g of 1 -methoxypropanol-2 The prepared unsaturated polyurethane had a solids content of about 75 wt %

Preparation of Unsaturated Polyurethane G

The following compounds were weighed into a 2 I reaction flask 265,5 g Tegomer^® D-3403,

282,9 g NaHSOa-compound,

267,0 g oleyl alcohol (available from Henkel under the trade designation

HD-Ocenol^® 90/95), and 100,0 g o-xylene

Unsaturated Polyurethane G was prepared following the procedure for the preparation of Unsaturated Polyurethane A, except that 66,2 g of methylethyl ketone were added to the reaction mixture and on completion of the reaction as above the reactor contents were diluted with 251 ,3 g of 1 -methoxy propanol- 2 The prepared unsaturated polyurethane had a solids content of about 75 wt %

Preparation of Unsaturated Polyurethane H

The following compounds were weighed into a 2 I reaction flask

194,7 g Tegomer^® D-3403,

334,6 g NaHSO₃-compound,

133,5 g Oleylalcohol (HD Ocenol^® 90/95),

500,0 g Polypropylene glycol (Mw = 2000), and

100,0 g o-xylene

Unsaturated Polyurethane H was prepared following the procedure for the preparation of Unsaturated Polyurethane A, except that 66,2 g of methylethyl ketone were added to the reaction mixture and on completion of the reaction as above the reactor contents were diluted with 251 ,3 g of 1 -methoxypropanol- 2 The prepared unsaturated polyurethane had a solids content of about 75 wt %

Unsaturated Polyurethane I

Unsaturated Polyurethane I was prepared from 033 molequivalents Tegomer^® D-3403, 067 molequivalents of NaHSO₃-compound, 2 molequivalents of 18

oieylalcohol (HD Ocenol^® 90/95), and 2 molequivalents isophorone diisocyanate LiOH H₂O was added until pH=7

Unsaturated Polyurethane J

Unsaturated Polyurethane J was prepared from 0 33 molequivalents Tegomer^® D-3403, 067 molequivalents of NaHSO₃-compound, 1 molequivalents of oieylalcohol (HD Ocenol^® 90/95), 1 molequivalents of polypropylene glycol 600, and 2,5 molequivalents isophorone diisocyanate LiOH H₂0 was added until pH=7.

Preparation of Aqueous Alkyd Dispersion

The following alkyd resins were employed-

Alkyd Resm A

Alkyd resin having an oil length of 55, acid number = 8,3 mg KOH/g, Mn = 3230, Mw = 71 160 dissolved in 1-methoxypropanol-2, and a solids content of 75 wt %.

Alkyd Resm B

Alkyd resm having an oil length of 65, acid number = 6,9 mg KOH/g, Mn = 3650, Mw = 47 980 dissolved in 1 -methoxypropanol-2, and a solids content of 80 wt.%.

Preparation of Aqueous Alkyd Dispersions Example 1

Into a 2 I reaction flask were weighed

550 g Alkyd Resin A (75 wt % in 1 -methoxypropaπol-2) and 116,7 g Unsaturated Polyurethane A (75 wt % in a mixture of methylethyl ketone and 1 -methoxypropaπol-2)

The mixture was heated to 130°C All solvents were distilled off under reduced pressure The mixture was cooled to about 90°C, and demineralised water was added slowly with vigorous stirring In all, 550 g demineralised water were added over 3 hours, with the temperature gradually being lowered to ambient Obtained was a stable aqueous alkyd dispersion having the properties listed in Table 1

Example 2

Example 1 was repeated, except that prior to the distilling off of the solvents 1 ,75 g of LiOH H₂O (= 2 wt %, calculated on the solid unsaturated polyurethane) were added to the mixture of alkyd resin and unsaturated polyurethane Obtained was a stable aqueous alkyd dispersion with the properties listed in Table 1 Compared with example 1 , the alkyd dispersion of example 2 has a smaller particle size and a higher pH

Examples 3 through 8

Example 2 was repeated, except that use was made of ever decreasing amounts of unsaturated polyurethane The amounts employed and the properties of the resulting alkyd dispersions are listed in Table 1 Although there was an increase in the average particle size of the alkyd dispersions in 20

examples 3-8, stable dispersions were obtained in all cases. There was an increase in solids contents from 50 to 62, while the average particle size increased from 164 to 527 nm

Examples 9 through 12

Example 2 was repeated, except that Alkyd Resm B was employed instead of Alkyd Resm A and Unsaturated Polyurethane B was used instead of Unsaturated Polyurethane A, the alkyd resin/polyurethane dispersing resm ratio being 85/15 (solids to solids) in all cases, with an increasing percentage of LiOH H₂O (calculated on the unsaturated polyurethane) in examples 9-12 In all cases stable alkyd dispersions in water were obtained, with properties as listed in Table 2.

Example 13

Weighed into a 2 I reaction flask were- 590,0 g Alkyd Resin A (75 wt % in 1 -methoxypropanol-2), 76,7 g Unsaturated Polyurethane C (75 wt.% in a mixture of methylethyl ketone and 1-methoxypropanol-2), and 1 ,064 g LiOH H₂O The mixture was heated to 130°C All solvents were distilled off under reduced pressure The mixture was cooled to about 90°C and demineralised water was added slowly with vigorous stirring In all, 365 g demineralised water were added over a period of 3 hours, with the temperature gradually being lowered to ambient Obtained was a stable aqueous alkyd dispersion having the properties listed in Table 3.

Examples 14 through 17

Example 13 was repeated, except that use was made of Unsaturated Polyurethanes D through G instead of Unsaturated Polyurethane C. Obtained were stable aqueous alkyd dispersions having properties as listed in Table 3.

Example 18

Weighed into a 2 I reaction flask were: 680,0 g Alkyd Resin A (75 wt % in 1 -methoxyρropanol-2),

120,0 g Unsaturated Polyurethane H (75 wt.% in a mixture of methylethyl ketone and 1-methoxypropanol-2), and

1 ,44 g LιOH.H₂O.

The mixture was heated to 130°C. All solvents were distilled off under reduced pressure The mixture was cooled to about 90^CC and demineralised water was added slowly with vigorous stirring In all, 438,5 g demineralised water were added over a period of 3 hours, with the temperature gradually being lowered to ambient Obtained was a stable aqueous alkyd dispersion having the properties listed in Table 3

Example 19

Example 14 was repeated, except that after removal of the solvent there were added to the mixture of alkyd and unsaturated polyurethane 2,175 g of Cobalt(ll)acetyl acetonate and 2,25 g of methylethyl ketoxim (anti-skinning agent) Obtained was a stable aqueous alkyd dispersion having the properties listed in Table 4

Example 20

Example 14 was repeated, except that after removal of the solvent there were added to the mixture of alkyd resin and unsaturated polyurethane 2,175 g of Cobalt(ll)acetyl acetonate, 1 ,8 g of Zr(IV)acetyl acetonate, and 2,25 g of methylethyl ketoxim (anti-skinning agent) Obtained was a stable aqueous alkyd dispersion having the properties listed in Table 4

Example 21

Solvent was removed from a mixture of 640 g Alkyd Resin A and 160 g Unsaturated Polyurethane D by distillation under reduced pressure at 130°C After removal of solvent the mixture was cooled to 80°C In a peπod of 30 minutes 500 g of this mixture were pumped into a 2 I reactor which was equipped with a stirrer and baffles and filled with 600 g demineralised water in which 2,5 g of LiOH H₂0 had been dissolved There was vigorous stirring during this process Obtained was a stable aqueous alkyd dispersion with pH=8 5, an average particle size of 135 nm, and a polydispersity of 003

Pigmented aqueous alkyd dispersions

Example 22

Weighed into a 2 I reaction flask were

500,0 g pigment paste composed of 68 wt % TιO₂, 12,6 wt % Alkyd

Resin B, and 19,4 wt % white spirit, 417,5 g Alkyd Resm A (75 wt % in 1 -methoxypropanol-2),

65,2 g Unsaturated Polyurethane A (75 wt % in a mixture of 1- methoxypropanol-2 and methylethylketone) and

1 ,44 g LiOH H₂O

The mixture was heated to 150°C All solvents were distilled off under reduced pressure The mixture was cooled to about 90°C, and demineralised water was added slowiy with vigorous stirring In all, 328 g demineralised water were added over a period of 3 hours, with the temperature gradually being lowered to ambient Obtained was a stable, pigmented aqueous alkyd dispersion having the properties listed in Table 5

Example 23

Example 22 was repeated, except that the following constituents and amounts were employed 500,0 g pigment paste composed of 68 wt % TιO2, 12,6 wt % Alkyd

Resm B, and 19,4 wt % white spirit, 397,6 g Alkyd Resm A (75 wt % in 1 -methoxypropanol-2),

85,0 g Unsaturated Polyurethane B (75 wt % in a mixture of 1- methoxypropanol-2 and methylethylketone) and 1 ,05 g LιOH H₂O

360 g demineralised water were added Obtained was a stable, pigmented aqueous alkyd dispersion having the properties listed in Table 5

Example 24

Example 22 was repeated, except that the following constituents and amounts were employed 500,0 g pigment paste composed of 68 t % TιO2, 12,6 wt % Alkyd

Resin B, and 19,4 wt % white spirit, 397,6 g Alkyd Resm A (75 wt % in 1 -methoxypropanol-2),

8,0 g Unsaturated Polyurethane B (75 wt % in a mixture of 1- methoxypropanol-2 and methylethylketone), and 1,05 g LιOH H₂O

After the solvent had been distilled off there were added. 7, 1 g Sologen^® Cobalt Aqua (containing 6 wt % of Co),

1 ,9 g methylethyl ketoxim (anti-skinning agent), and

344 g demineralised water Obtained was a stable pigmented aqueous alkyd dispersion having the properties listed in Table 5

Unsaturated polyurethanes as Pigment Dispersants Example 25

Into a 2 I flask were weighed 400,0 g Unsaturated Polyurethane A (75 wt % in a mixture of 1 -methoxypropanol-2 and methylethylketone) and 0,45 g LiOH H₂0 The mixture was heated to 130°C, and all solvents were distilled off under reduced pressure The mixture was cooled to about 90^CC, and 670 g demineralised water were added over a period of 3 hours with vigorous stirring of the contents of the reaction flask while the temperature was gradually lowered to ambient Obtained was a colloidal dispersion having the properties listed in Table 6

Example 26

Example 25 was repeated, except that use was made of 400,0 g Unsaturated Polyurethane C (75 wt % in a mixture of 1 -methoxypropanol-2 and methylethylketone) and 0,3 g LiOH H₂O After the solvents had been distilled off, 700 g demineralised water were added Obtained was a colloidal dispersion having the properties listed in Table 6

Example 27

Example 26 was repeated, except that use was made of 400 g Unsaturated Polyurethane D (75 wt % in a mixture of 1 -methoxypropanol-2 and methylethylketone) and 0,225 LiOH H₂O Obtained was a colloidal dispersion having the properties listed in Table 6

Example 28 Example 27 was repeated, except that use was made of 400 g Unsaturated Polyurethane H (75 wt % in a mixture of 1-methoxypropanol-2 and methylethylketone) and 0,18 g LiOH H₂O Obtained was a colloidal dispersion having the properties listed in Table 6

The aqueous unsaturated polyurethanes according to the invention are also readily usable as pigment (in these examples, TιO₂) dispersing agents Stable pigment pastes were obtained using unsaturated polyurethanes of examples 25-28 In these examples, about 1-10 wt % (on solids) unsaturated polyurethanes are used in relation to TιO₂

Composite Latexes (Composite Polymer Dispersions)

Example 29

In a 2 I reaction flask equipped with a stirrer, a thermometer, a reflux condenser, and two dropping funnels a mixture composed of 520,8 g alkyd dispersion from Example 15 (57,6 wt % of solids) and 222,8 g demineralised water was homogenised

The first Dropping Funnel A was filled with a pre-emuision composed of 0,8 g sodium dodecyl benzene sulphonic acid,

69,9 g demineralised water,

50,0 g methyl methacrylate, and 0 156

27

150,0 g butyl methacrylate

The second Dropping Funnel B was filled with a homogeneous mixture of 1 g sodium persulphate and 100 g demineralised water

After deaeration the reaction flask and the dropping funnels were placed under a nitrogen atmosphere The contents of the reaction flask were heated to 85°C, after which the contents of Dropping Funnel A and 95% of the contents of Dropping Funnel B were added to the reaction flask over a period of 1,5 hours, with the temperature of the contents of the reaction flask being kept at 85°C After the contents of the reaction flask had been kept at 85°C for one hour, the remaining contents of Dropping Funnel B were added to the reaction flask, which was then kept at 85°C for an additional hour The contents were cooled to ambient temperature, and the composite latex was filtered to remove a slight amount of coagulation The properties of the obtained composite latex are listed in Table 7

Example 30

In a 2 I reaction flask equipped with a stirrer, a thermometer, a reflux condenser, and two dropping funnels a mixture composed of 434,0 g Alkyd dispersion from Example 15 (57,6 wt % of solids) and

217,6 g demineralised water was homogenised

The first Dropping Funnel A was filled with a pre-emulsioπ composed of 1 g sodium dodecyl benzene sulphonic acid,

87,3 g demineralised water, 62,5 g methyl methacrylate, and

187,5 g butyl methacrylate

The second Dropping Funnel B was filled with a homogeneous mixture of 1 ,25 g sodium persulphate and

125 g demineralised water

After deaeration the reaction flask and the dropping funnels were placed under a nitrogen atmosphere The contents of the reaction flask were heated to 85°C, after which the contents of Dropping Funnel A and 95% of the contents of Dropping Funnel B were added to the reaction flask over a period of 2 hours, with the temperature of the contents of the reaction flask being kept at 85°C After the contents of the reaction flask had been kept at 85°C for one hour, the remaining contents of Dropping Funnel B were added to the reaction flask, which was then kept at 85°C for an additional hour The contents were cooled to ambient temperature, and the composite latex was filtered to remove a slight amount of coagulation The properties of the obtained composite latex are listed in Table 7

Unsaturated polyurethanes as pigment dispersants in pigmented agueous alkyd dispersions

Examples 31-33

A pigment paste A was prepared from 35 g water, 2,4 g nonionic and anionic dispersant, i e Atsurf ex ICI, 4,5 g wetting agent, i e Surfynol TG ex Air Products, 106 g TιO₂, 0,36 defoamer, i e. Byk 24, and 1 ,85 g of a heur thickener, i.e RM 2020, ex Rohm & Haas A pigment paste B was prepared from 26 g water, 13,5 Unsaturated Polyurethane J, 4,5 g wetting agent, I e Surfynol TG ex Air Products , 106 g TιO₂, and 0,36 defoamer, i e Byk 24

Both pigment pastes A and B were used to prepare pigmented aqueous alkyd dispersions A 150 μ layer was applied with the pigmented aqueous coating compositions The gloss of the wet paint was measured The Konig hardness was measured after several drying peπods The drying velocity of the applied coating composition at 10°C was followed directly after preparation of the coating composition and after an aging period of 4 weeks at 35°C of the coating composition The compounds and amounts used and the resulting properties of the dispersions and coating compositions are listed in Table 8

Table 1 Aqueous alkyd dispersions

Composition Examples

1 2 3 4 5 6 7 8

Alkyd Resin A (wt.%) 82,5 82,5 83,5 87,5 89,5 91 ,5 92,5 93,5

UP A (wt %)¹ 17,5 17,5 16,5 12,5 10,5 8,5 7,5 6,5

LιOH.H₂O (wt.%) 2,0 1 ,75 1 ,8 1 ,9 2,1 2,25 2,45 (calc. on UP A)

Properties wt % solids 49,6 46,6 49,9 55,1 58,0 60,2 61 ,2 62,3 viscosity (Pa.s) 0,44 0,12 0,32 0,30 0,32 0,23 0,30 0,24

PH 4, 1 8,7 8,15 7,7 7,9 7,6 7,9 7,9 particle size (nm) 293 148 164 215 263 320 373 527 polydispersity 0,05 0,03 0,01 0,05 0,01 0,15 0,09 0,03

UP=Uπsaturated Polyurethane

Table 2

Aqueous alkyd dispersions

Composition Examples

9 10 11 12

Alkyd Resin B (wt %) 85 85 85 85

Unsaturated Polyurethane B (wt %) 15 15 15 15

LiOH H₂O (wt %) 1,5 2,0 2,6 3,0 (calc on UP¹ B)

Properties wt % solids 60,9 58,0 53,9 50,9 viscosity (Pa s) 0,23 0,19 0,21 0,17

PH 6,5 6,75 7,6 7,8 particle size (nm) -3000 740 256 236 polydispersity - 0,08 0,03 0,08

Table 3

Aqueous alkyd dispersions

UP=Uπsaturated Polyurethane

Table 4

Aqueous alkyd dispersions

Composition Examples

19 20

Alkyd Resin A (wt %) 88,5 88,5

Unsaturated Polyurethane D (wt %) 11,5 11,5

LiOH H₂O (wt %) 1 ,85 1,85 (calc on UP¹ D)

Co(ll)AcAc 0,435 0,435

Zr(IV)Ac Ac - 0,360 anti-skinning agent 0,45 0,45

Properties wt % solids 57,6 56,4 viscosity (Pa s) 0,29 0,21

PH 7,9 7,8 particle size (nm) 236 221 polydispersity 0,03 0,03

UP=Unsaturated Polyurethane

Table 5

Pigmented aqueous alkyd dispersions

Properties Examples

22 23 24 wt % solids 70,0 67,0 67,8 viscosity (Pa s) 0,61 0,37 0,50

PH 7,6 7,8 7,2 particle size (nm)¹ 540 610 510

Malvern, small angle light scattering

Table 6

Pigment unsaturated polyurethanes

Properties Examples

25 26 27 28 wt.% solids 30,9 29,8 29,9 29,8 viscosity (Pa s) 1,90 0,82 0,91 0,82

PH 7,9 7,6 7,4 7,0 Table 7

Composite latexes

Properties Examples

29 30 wt.% solids 44,8 44,6 viscosity (Pa.s) 0,03 0,04 pH 6,9 6,5 particle size (nm) 207 208 polydispersity 0,04 0,10

Table 8

Composition Examples

31 32 33

Alkyd Resin A (88,5 wt.%)+ UP¹ I (11 ,5 wt%) 56 g 48 g 50 g water 3,8 g 16 g 11,3 g

Co siccative: ASK 2005, ex. Ashland i g 0,9 g 0,9 g methylethylketoxim 0,5 g 0,5 g 0,5 g

Pigment Paste A 35,9 g 32 g

Pigment Paste B 32,8 g

RM 2020, ex. Rohm & Haas 2,8 g 6 g 5 g

Dispersion properties wt.% solids 47 41 41

ICI viscosity 3 3 3 pH 7,1 7 7,1

Paint properties

Gloss (20°C, after 1 day) 84 87 83

Kόnig Hardness (1 day, 1 week, 100 6/8/25 8/9/25 9/16/27 hrs/50°C)

Drying (10 °C) ok ok ok

Drying (10°C after aging for 4 weeks/35°C) ok ok ok

UP=Unsaturated Polyurethane

Claims

1 A water-dispersible unsaturated polyurethane comprising pendant unsaturated alkyl groups, pendant sulphonic acid salt groups, and polyoxyalkylene groups, said sulphonic acid salt groups and said polyoxyalkylene groups being present in amounts at least sufficient to render said unsaturated polyurethane water dispersible, characterised in that the polyoxyalkylene groups are pendant alkoxy polyoxyalkylene groups

2 An unsaturated polyurethane according to claim 1 , characterised in that the alkoxy polyoxyalkylene groups are C1-C4 alkoxy polyoxyalkylene groups

3 An unsaturated polyurethane according to claim 2, characteπsed in that the alkoxy polyoxyalkylene group is a methoxypolyoxyethylene group, a methoxypolyoxypropylene group, or a combination thereof

4 An unsaturated polyurethane according to any one of the preceding claims, characterised in that the alkoxy polyoxyalkylene group has an average molecular weight of 500-3000

5 An unsaturated polyurethane according to any one of the preceding claims, characteπsed in that said unsaturated polyurethane compπses a) 10-40 wt % alkoxy polyoxyalkylene groups, b) 0,1-0,5 meq/g sulphonic acid alkali metal salt groups, and c) 10-35 wt % unsaturated alkyl groups

6 An unsaturated polyurethane according to any one of the preceding claims, characterised in that said unsaturated polyurethane comprises a chain extender group

7 An unsaturated polyurethane according to claim 6, characteπsed in that said chain extender group is derived from a polyester diol or polyether

8 An unsaturated polyurethane according to any one of the preceding claims, characterised in that one or more of the unsaturated alkyl groups are polyunsaturated

9 An unsaturated polyurethane according to any one of the preceding claims, characterised in that the sulphonic acid salt groups are derived from a sulphosuccmate diester diol

10 An unsaturated polyurethane according to any one of the preceding claims, characterised in that the unsaturated alkyl groups are derived from a compound which is a reaction product of an unsaturated fatty acid and mono-epoxide

11 An unsaturated polyurethane according to any one of the preceding claims, characterised in that the unsaturated polyurethane further comprises a compound derived from a isocyaπate-functional compound

12. An aqueous alkyd dispersion comprising an unsaturated polyurethane according to any one of the preceding claims An aqueous alkyd dispersion according to claim 12, characteπsed in that the alkyd resm is wholly or partially neutralised with alkaii metal hydroxide

An aqueous alkyd dispersion according to any of the preceding claims 12 and 13, characterised in that said dispersion comprises 5-25 wt % unsaturated polyurethane and 95 to 75 wt.% alkyd resm

An aqueous alkyd dispersion according to any one of claims 12 to 14, characterised in that the alkyd resin has an oii length of 40-90 and an acid number of 5-10 mg KOH/g.

A process for preparing a polymer dispersion, characterised in that monoethylenically unsaturated monomers are reacted in the presence of an alkyd dispersion according to any one of the preceding claims 12 to 15.

A process according to claim 16, characteπsed in that the monoethylenically unsaturated monomers are alkyl (meth)acrylate compounds

A process according to claim 17, characterised in that the alkyl (meth)acrylate is selected from the group of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, or isobutyl (meth)acrylate and mixtures thereof

Use of an unsaturated polyurethane according to any one of the preceding claims 1-11 for emulsifying an alkyd resin in water. Use of an unsaturated polyurethane according to any one of the preceding claims 1-11 for dispersing pigments in water

Use of an unsaturated polyurethane according to any one of the preceding claims 1-11 in a pigmented coating composition comprising an alkyd resin and a pigment or pigment paste

Use of a polymer dispersion prepared according to any one of the preceding claims 16-18 in a pigmented coating composition comprising a pigment or pigment paste