WO2007039605A1

WO2007039605A1 - Amphiphilic polyamine dispersant resin

Info

Publication number: WO2007039605A1
Application number: PCT/EP2006/066988
Authority: WO
Inventors: Hendrik Jan Willem Van Den Haak; Jamie Macliver Roy; Michel Menting
Original assignee: Akzo Nobel Coatings International BV
Current assignee: Akzo Nobel Coatings International BV
Priority date: 2005-10-04
Filing date: 2006-10-03
Publication date: 2007-04-12
Anticipated expiration: 2008-04-04

Abstract

The invention relates to an amphiphilic polyamine dispersant resin having a polyamine backbone and pendent side groups, wherein the side groups comprise a) at least one side group substantially compatible with water linked to the polyamine backbone via a covalent bond, and b) at least one hydrophobic side group substantially compatible with at least one organic solvent.

Description

AMPHIPHILIC POLYAMINE DISPERSANT RESIN

The invention relates to an amphiphilic polyamine dispersant resin having a polyamine backbone and pendent side groups. The invention further relates to pigment compositions comprising the polyamine dispersant resin, a process for dispersing pigments, and water and solvent borne coating compositions comprising the pigment compositions.

The use of an amphiphilic pigment dispersant offers considerable advantages to the paint industry. The fact that one pigment composition comprising the amphiphilic dispersant resin can be used in both water and solvent borne coating compositions simplifies the logistics of production as well as distribution.

A polyamine dispersant resin of the above-mentioned type is known from US patent 6,111 ,054. This document relates to the use of compounds obtainable by the reaction of organic acids with polyamines as dispersing agents for organic and inorganic pigments and for extenders and fillers in organic and aqueous systems, so-called amphiphilic dispersants. The organic acids in one pendent side group comprise water-compatible blocks, such as polyethers, and solvent- compatible blocks, such as polycaprolactone. Exemplified is a side chain with a total number average molecular weight Mn of 900. A drawback is the inferior stability of pigment compositions prepared from such dispersants.

Accordingly, the invention seeks to provide an amphiphilic polyamine dispersant resin which permits the preparation of stable pigment compositions. It also permits the preparation of pigment concentrates which can be easily incorporated into both water and solvent borne coating compositions wherein the pigments are stably dispersed. In addition, the dispersant resin should be suitable for use with a wide range of pigments. The pigment compositions should allow the preparation of both solvent and water borne paints having excellent properties and stability, especially in the case of pigments which are difficult to disperse and stabilize.

The invention now provides an amphiphilic polyamine dispersant resin having a polyamine backbone and pendent side groups, wherein the side groups comprise a) at least one side group substantially compatible with water linked to the polyamine backbone via a covalent bond, and b) at least one hydrophobic side group substantially compatible with at least one organic solvent.

The polyamine dispersant resin of the invention can suitably be prepared by reacting

(a) at least one di- or polyamine, (b) at least one compound having at least one amine-reactive group and a pendent hydrophilic group, and,

(c) at least one compound having at least one amine-reactive group and a pendent hydrophobic group.

As suitable di- or polyamines aliphatic amines may be mentioned. Preferably, these aliphatic amines contain at least three primary, secondary, and/or tertiary amine groups. Aliphatic linear polyamines comprising primary and secondary amino groups may be used, such as diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylene hexamine, hexaethylene heptamine, and higher homologues. Preferably, aliphatic branched polyamines are used, particularly (C2-C4)-alkylene amines, which comprise primary, secondary, and tertiary amino groups and which have molecular weights of 600-2,000,000 g/mole, such as the Lupasol® types produced by BASF or the Epomin® types produced by Nippon Shokubai. These branched aliphatic polyamines, which are also known as polyimines or polyaziridines, are produced by known methods, e.g. by the polymerization of ethylene imine. Of these aliphatic branched polyamines, types with an average Mw of about 600-3,000 g/mole are preferably used, more preferably types with an average Mw of about 1 ,000-2,500 g/mole.

Suitable compounds (b) can be obtained by the reaction of at least one compound having at least two isocyanate groups with a polyalkylene oxide based group having at least one isocyanate-reactive group. The polyalkylene oxide based group having at least one isocyanate-reactive group may be selected from polyalkylene glycol monoalkyl ether and polyoxyalkylene monoamine. Examples of suitable alkylene oxides are ethylene oxide, propylene oxide, butylene oxide, or mixtures thereof. It is preferred that the polyalkylene oxide based side groups are based on ethylene oxide or a mixture of ethylene oxide and propylene oxide.

In a preferred embodiment the polyalkylene oxide based group having at least one isocyanate-reactive group is a compound according to formula (I) or (II), or a mixture thereof,

H₂N I]C₃H₆O)H(C₂H₄O)Ri]-R₁ HO I]C₃H₆O)H(C₂H₄O)RTI-R₁ (0 (H)

wherein R¹ is selected from Ci to C₄ alkyl groups, n is 0 to 25, m is 1 to 50, and n+m < 50. It is to be understood that the (CsH₆O) and (C2H₄O) units may be present in the compound as blocks of polypropylene oxide and polyethylene oxide or as a more or less random mixture of propylene oxide and ethylene oxide derived units. Examples of suitable amines according to formula (I) are polyoxyalkylene monoamines, which are commercially available from Huntsman under the trade designation Jeffamine^® M.

Examples of suitable ethers according to formula (II) are polyalkylene oxide based alkoxy compounds, which are commercially available from Clariant under the trade designation Polyglykol M.

Examples of compounds having at least two isocyanate groups include 1 ,6- diisocyanatohexane, isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6- toluene diisocyanate, diphenyl methane-diisocyanate, 4,4'-bis(isocyanato- cyclohexyl) methane, 1 ,4-diisocyanatobutane, 1 ,5-diisocyanato-2,2-dimethyl pentane, 2,2,4-trimethyl-1 ,6-diisocyanatohexane, 1 ,10-diisocyanatodecane, 4,4- diisocyanato-cyclohexane, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydro- toluene diisocyanate, norbornane diisocyanate, 1 ,3-xylylene diisocyanate, 1 ,4- xylylene diisocyanate, 1-isocyanato-3-(isocyanato methyl)-1 -methyl cyclo- hexane, m-α,α-α',α'-tetramethyl xylylene diisocyanate, and mixtures thereof.

In the preparation of the polyamine dispersant resin the amount of compounds having at least one amine-reactive group and a pendent hydrophilic polyalkylene oxide based group is selected such as to ensure that the content of polyalkylene oxide in the polyamine dispersant resin is at least 10 weight-%, calculated on the weight of the dispersant. Preferably, the amount of polyalkylene oxide in the polyamine dispersant resin does not exceed 80 weight-%. It is most preferred that the amount of polyalkylene oxide is in the range of 20 to 50 weight-%. The polyamine dispersant resin preferably comprises at least two, more preferably at least three pendent hydrophilic polyalkylene oxide based side groups per molecule. The hydrophobic side groups are different from the hydrophilic side groups. The term hydrophobic describes the tendency of a molecule or molecular group not to penetrate water or to leave the aqueous phase, as defined in DIN EN ISO 862: 1995-10. Suitable compounds (c) may include acid-terminated hydrophobic groups (c1 ), the reaction product of at least one compound having at least two isocyanate groups with a long-chain alcohol (c2), or mixtures thereof.

Examples of acid-terminated hydrophobic groups (c1 ) include acid-terminated polyesters such as those obtainable by the acid-initiated polymerization of a lactone (e.g. propiolactone, valerolactone, caprolactone) or by the condensation of hydroxy-carboxylic acids (e.g. 12-hydroxy stearic acid, ricinoleic acid, commercially available from Akzo Nobel as Nouracid CS80, and hydroxyl caproic acid). The acid groups provide the reaction with the amine groups of the polyamine backbone by forming a salt, an amide, or a combination thereof.

Examples of the reaction product of at least one compound having at least two isocyanate groups with a long-chain alcohol (c2) include the above-mentioned diisocyanates reacted with long-chain mono-alcohols, e.g. hydrogenated polybutadiene with one terminal hydroxyl group, which are commercially available from Shell under the trade designation Kraton^®, e.g. Kraton LiquidTM L-1203, or alcohol-initiated polycaprolactone.

The amount of compounds having hydrophobic groups used in the preparation of the polyamine dispersant resin may be selected such as to ensure that the content of hydrophobic groups in the polyamine dispersant resin is at least 20 weight-%, calculated on the weight of the dispersant. Preferably, the amount of hydrophobic groups in the polyamine dispersant resin does not exceed 80 weight-%. It is most preferred that the amount of hydrophobic groups is in the range of 40 to 70 weight-%. The polyamine dispersant resin preferably comprises at least two, more preferably at least three pendent hydrophobic based side groups per molecule. The pendent hydrophobic side groups may be linked to the polyamine backbone via covalent bonds or via ionic bonds. Also a combination of covalently and ionically linked pendent hydrophobic side groups is possible.

Preferably, the side groups have a number average molecular weight Mn of 500 to 4,000, more preferably of 1 ,000 to 2,000.

The polyamine dispersant resin can be prepared in a conventional manner. The polyamine dispersant may be prepared by reacting the polyamine backbone with the hydrophilic and hydrophobic tails, either simultaneously or in two consecutive steps. The order of reaction (simultaneous, hydrophobes first, or hydrophiles first) depends on the types of amino-reactive groups used in the different tails and can easily be decided by those skilled in the art.

The invention also relates to a composition comprising the polyamine dispersant resin and a pigment. Compositions comprising a high proportion of pigment, i.e. pigment concentrates, are preferred, because such compositions are particularly effective in providing colour and hiding to coatings. The pigment concentrates generally comprise 5 to 85 weight-%, preferably 20 to 75 weight-% of pigment, based on the total weight of the pigment concentrate. The pigment preparation of the invention may comprise an inorganic or an organic pigment. It is also possible for the pigment preparation to comprise a plurality of different pigments, for example two or more inorganic pigments, two or more organic pigments, or a mixture of one or more inorganic pigments and one or more organic pigments.

The organic pigments typically are organic chromatic and black pigments. Inorganic pigments can likewise be colour pigments (chromatic, black, and white pigments), as well as luster pigments and the inorganic pigments typically used as fillers.

The following are examples of suitable organic colour pigments: monoazo pigments:

C.I. Pigment Brown 25; C.I. Pigment Orange 5, 13, 36, 38, 64, and 67; C.I.

Pigment Red 1 , 2, 3, 4, 5, 8, 9, 12, 17, 22, 23, 31 , 48:1 , 48:2, 48:3, 48:4, 49,

49:1 , 51 :1 , 52:1 , 52:2, 53, 53:1 , 53:3, 57:1 , 58:2, 58:4, 63, 112, 146, 148, 170,

175, 184, 185, 187, 191 :1 , 208, 210, 245, 247, and 251 ; C.I. Pigment Yellow 1 , 3, 62, 65, 73, 74, 97, 120, 151 , 154, 168, 181 , 183, and 191 ; C.I. Pigment Violet

32; diazo pigments:

C.I. Pigment Orange 16, 34, 44, and 72; C.I. Pigment Yellow 12, 13, 14, 16, 17,

81 , 83, 106, 113, 126, 127, 155, 174, 176, 180, and 188; diazo condensation pigments:

C.I. Pigment Yellow 93, 95, and 128; C.I. Pigment Red 144, 166, 214, 220, 221 ,

242, and 262; C.I. Pigment Brown 23 and 41 ; anthanthrone pigments:

C.I. Pigment Red 168; anthraquinone pigments:

C.I. Pigment Yellow 147, 177, and 199; C.I. Pigment Violet 31 ; anthrapyrimidine pigments:

C.I. Pigment Yellow 108; quinacridone pigments: Pigment Orange 48 and 49; C.I. Pigment Red 122, 202, 206, and 209; C.I.

Pigment Violet 19; quinophthalone pigments:

C.I. Pigment Yellow 138; diketopyrrolopyrrole pigments: C.I. Pigment Orange 71 , 73, and 81 ; C.I. Pigment Red 254, 255, 264, 270, and

272; dioxazine pigments:

C.I. Pigment Violet 23 and 37; C.I. Pigment Blue 80; flavanthrone pigments:

C.I. Pigment Yellow 24; indanthrone pigments:

C.I. Pigment Blue 60 and 64; isoindoline pigments: C.I. Pigments Orange 61 and 69; C.I. Pigment Red 260; C.I. Pigment Yellow

139 and 185; isoindolinone pigments:

C.I. Pigment Yellow 109, 110, and 173; isoviolanthrone pigments: C.I. Pigment Violet 31 ; metal complex pigments:

C.I. Pigment Red 257; C.I. Pigment Yellow 117, 129, 150, 153, and 177; C.I.

Pigment Green 8; perinone pigments: C.I. Pigment Orange 43; C.I. Pigment Red 194; perylene pigments:

C.I. Pigment Black 31 and 32; C.I. Pigment Red 123, 149, 178, 179, 190, and

224; C.I. Pigment Violet 29; phthalocyanine pigments: C.I. Pigment Blue 15, 15:1 , 15:2, 15:3, 15:4, 15:6, and 16; C.I. Pigment Green 7 and 36; pyranthrone pigments:

C.I. Pigment Orange 51 ; C.I. Pigment Red 216; pyrazoloquinazolone pigments: C.I. Pigment Orange 67; C.I. Pigment Red 251 ; thioindigo pigments:

C.I. Pigment Red 88 and 181 ; C.I. Pigment Violet 38; triarylcarbonium pigments:

C.I. Pigment Blue 1 , 61 , and 62; C.I. Pigment Green 1 ; C.I. Pigment Red 81 , 81 :1 , and 169; C.I. Pigment Violet 1 , 2, 3, and 27; C.I. Pigment Black 1 (aniline black); C.I. Pigment Yellow 101 (aldazine yellow); C.I. Pigment Brown 22.

Examples of suitable inorganic colour pigments are: white pigments: titanium dioxide (C.I. Pigment White 6), zinc white, pigment grade zinc oxide; zinc sulfide, lithopone; black pigments: iron oxide black (C.I. Pigment Black 11 ), iron manganese black, spinel black (C.I. Pigment Black 27); carbon black (C.I. Pigment Black 7); chromatic pigments: chromium oxide, chromium oxide hydrate green; chrome green (C.I. Pigment Green 48); cobalt green (C.I. Pigment Green 50); ultramarine green; cobalt blue (C.I. Pigment Blue 28 and 36; C.I. Pigment Blue 72); ultramarine blue; manganese blue; ultramarine violet; cobalt violet; manganese violet; red iron oxide (C.I. Pigment Red 101 ); cadmium sulfoselenide (C.I. Pigment Red 108); cerium sulfide (C.I. Pigment Red 265); molybdate red (C. I. Pigment Red 104); ultramarine red; brown iron oxide (C.I. Pigment Brown 6 and 7), mixed brown, spinel phases and corundum phases (C.I. Pigment Brown 29, 31 , 33, 34, 35, 37, 39, and 40), chromium titanium yellow (C.I. Pigment Brown 24), chrome orange; cerium sulfide (C.I. Pigment Orange 75); yellow iron oxide (C.I. Pigment Yellow 42); nickel titanium yellow (C.I. Pigment Yellow 53; C.I. Pigment Yellow 157, 158, 159, 160, 161 , 162, 163, 164, and 189); chromium titanium yellow; spinel phases (C.I. Pigment Yellow 119); cadmium sulfide and cadmium zinc sulfide (C.I. Pigment Yellow 37 and 35); chrome yellow (C.I. Pigment Yellow 34); bismuth vanadate (C.I. Pigment Yellow 184). Examples of inorganic pigments typically used as fillers are transparent silicon dioxide, ground quartz, aluminium oxide, aluminium hydroxide, natural micas, natural and precipitated chalk, and barium sulfate.

Luster pigments are platelet-shaped pigments having a monophasic or polyphasic construction the colour play of which is marked by the interplay of interference, reflection, and absorption phenomena. Examples are aluminium platelets and aluminium, iron oxide, and mica platelets bearing one or more coats, especially of metal oxides.

The composition suitably comprises up to 150 weight-%, preferably 1 to 100 weight-%, and most preferably 2 to 50 weight-% of the polyamine dispersant resin of the invention, calculated on the weight of the pigment. The most suitable amount of polyamine dispersant resin depends, among others, on the particular type of pigment to be dispersed. The mixture may optionally comprise other known additives, such as additional dispersing agents, anti-foaming agents, and/or polymeric or oligomeric binders. In one embodiment, the pigment composition may comprise a pigment synergist, such as Solsperse 5000 or 12000 commercially available from Noveon. This additive may be added in an amount ranging from 0.01 to 5 weight-% on the total composition.

The composition may be a liquid composition comprising an organic and/or an aqueous based diluent. In one embodiment, the pigment preparation of the invention is a free-flowing powder which is suitable for use as a stir-in pigment. Also solid compacted pigment preparations can be used, for example in the form of pellets or tablets.

The pigment concentrates or tinting pastes can be obtained by a process wherein a liquid mixture comprising a pigment, the polyamine dispersant resin of the invention, and optionally a liquid diluent are subjected to shear force. The pigment dispersant resin of the invention can be used in combination with one or more other pigment dispersion aids and/or surfactants. Examples of suitable equipment for carrying out the process are bead mills, jet mills, ultrasonic mills, basket mills, roll mills, and high-speed dissolvers. Inorganic or organic pigments or mixtures thereof may be used. In view of the amphiphilic properties of the polyamine dispersant resin, either water or organic solvents may be used, such as glycols, glycol ethers, glycol esters, or ether esters, for example ethylene glycol or higher homologues thereof, ethylene glycol mono-n-butyl ether, propylene glycol methyl ether acetate, or ethylethoxy propionate.

In use, the pigment preparations of the present invention are notable for their excellent colour properties, especially with regard to colour strength, brilliance, hue and hiding power, and especially for their stir-in characteristics, i.e. they can be dispersed in application media with a minimal input of energy, simply by stirring or shaking.

The pigment preparations of the present invention additionally have the following advantages: they have a high pigment content, exhibit very good stability in storage, are both economically and ecologically advantageous with regard to packaging, storage, and transportation, and they are more flexible in use, i.e. they can be used for pigmenting water borne compositions as well as solvent borne compositions.

The invention further relates to a coating composition comprising at least one organic film-forming binder, at least one pigment, and a pigment dispersant resin, wherein the pigment dispersant resin is a polyamine dispersant resin as described above. In view of the amphiphilic properties of the polyamine dispersant resin the coating composition may be an aqueous coating composition as well as a solvent borne coating composition. The coating composition may for example be a base coat composition. Base coat compositions are colour- and/or effect-imparting coating compositions which are used in multilayer lacquer systems having a clear top coat. Such multilayer lacquer systems are frequently used to protect and decorate motor vehicles and large transportation vehicles.

The coating composition may further comprise other ingredients, additives or auxiliaries commonly used in coating compositions, such as dyes, levelling agents, organic solvents, wetting agents, anti-cratering agents, anti-foaming agents, antisagging agents, heat stabilizers, light stabilizers, UV absorbers, antioxidants, and fillers.

The pigment concentrate can be part of a modular system for the preparation of a pigmented coating composition. Such a modular system may, for example, comprise one or more pigment concentrates as a tinting module, a binder module, and a reducer module. The base coat compositions mentioned above can suitably be prepared by mixing the modules of such a modular system.

Examples

The amounts of components in compositions and mixtures are given in parts by weight (pbw).

Raw materials used: Autowave Water borne modular base coat system ex Akzo

Nobel Car Refinishes Autowave 665 Clear base module of Autowave comprising a blend of polyurethane and acrylic resin dispersions ex

Akzo Nobel Car Refinishes Autowave 099 White toner module of Autowave ex Akzo Nobel Car

Refinishes Autobase Plus Solvent borne modular base coat system ex Akzo

Nobel Car Refinishes Q110 White toner module of Autobase Plus ex Akzo Nobel

Car Refinishes

Autoclear MS 2000 Modular clear coat system ex Akzo Nobel Car

Autocryl Hardener MS 30 Refinishes 1.2.3 Thinner Fast

Autoclear LV Ultra Modular clear coat system ex Akzo Nobel Car

Ultra Fast Hardener Refinishes

Ultra Thin

Setalux 6801 AQ-24 Aqueous acrylic dispersion ex Nuplex Resins

Setalux 1385 BX-51 Solvent based acrylic resin ex Nuplex Resins

Bayhydrol VPLS 2952 Aqueous polyurethane dispersion ex Bayer

MaterialScience

CAB 381 Cellulose acetate butyrate types ex Eastman

Chemical Company

Setal 1616 ss-75 Polyester ex Nuplex Resins Setal 168 ss-80 Polyester ex Nuplex Resins Binder mix 1 : A mixture of common solvents (79.23 pbw), CAB

381-0.1 (14.48 pbw), and CAB 381-20 (6.29 pbw) Binder mix 2: A mixture of Setal 1616 ss-75 (25.6 pbw), a surface tension modifier (11.78 pbw), Setal 168 ss-80 (21.31 pbw), and a wax additive (41.31 pbw) General methods:

The solids content of the compositions was determined by measuring the weight loss after heating a sample to 140⁰C for 30 minutes. The molecular weights were determined by size exclusion chromatography using polystyrene as standard.

The fineness of the pigment dispersions was determined with a Hegman gauge. The reported fineness value in μm represents the largest particles found in the sample.

The gloss of the coatings was measured using a Byk Gardner micro TRI gloss unit.

The transparency of the coatings was measured on foil against a reference foil without coating. The reference foil has a transparency of 100%. The colour was measured using a spectrophotometer and L^*a^*b^* values according to the CIE Lab system.

Example 1

Preparation of a polyamine dispersant resin according to the invention

1.1 Synthesis of acid-functional caprolactone Into a glass reactor equipped with a cooler, a thermocouple, and a mechanical stirrer were charged 1 ,420 g of ε-caprolactone (12.4 mole), 200 g lauric acid (0.998 mole), and 3.2 g titanium (IV) isopropoxide as catalyst. The mixture was heated under a nitrogen atmosphere to 170⁰C and kept at that temperature until the solids content was >98% (ca 24 hrs).

1.2 Synthesis of mPEG/ IPDI

In a glass reactor equipped with a cooler, a thermocouple, and a mechanical stirrer, 137 g isophorone diisocyanate (IPDI) (0.62 mole) in 200 g dry toluene and 1.50 g dibutyl tin dilaurate (DBTDL) were heated to 50°C using an oil bath. A dry mixture of 280 g toluene and 617.1 g polyethylene glycol monomethyl- ether of average molecular weight 1 ,000 (mPEG 1000) (0.617 mole) was added to the reaction mixture in 2 hours. Heating was continued until an isocyanate content of 2.1 % was obtained.

1.3 Synthesis of an amphiphilic dispersant

In a glass reactor equipped with a cooler, a thermocouple, a mechanical stirrer, and a Dean Stark separator, 44.22 g of polyethylene imine Lupasol PR 8515 ex BASF (0.024 mole), 403.28 g of acid-functional polycaprolactone as prepared in section 1.1 (0.247 mole), and 209.19 g toluene were heated under a nitrogen atmosphere to reflux (ca 124°C). The reaction water was removed. When an acid value of 13.0 mg KOH/g was obtained, the reaction mixture was cooled to 50⁰C and dried at 50⁰C for 2 hours using molecular sieve (2A). Then, 450.49 g of a solution of mPEG/IPDI as prepared in section 1.2 (0.225 mole) were added to the reaction mixture at 50°C in 2 hours. After 3 hours of post-reaction the toluene was removed by vacuum distillation.

The obtained product was a slightly yellow/orange solid material with an acid value of 13.5 mg KOH/g, a Mw of 7,258, and a Mn of 2,488. Example 2 Use of the dispersant resin for dispersing pigments

Pigment pastes were prepared with the polyamine dispersant resin of Example 1 , a red pigment Irgazin DPP Red BO ex Ciba, and several solvents. The pastes were shaken for 1.5 hours with 600 g zirconox beads 1.2-1.7 mm on a Skandex Paint Shaker Model No. SO 400. After shaking, the beads were separated by centrifugal force. The compositions of the pastes are summarized in Table 1 below.

Acceptable pastes were obtained with all three solvents. Table 1 : pigment pastes

Example 3

Use of pigment pastes in water borne coating compositions

Water borne coating compositions suitable as base coats were prepared as shown in Table 2.

Table 2: water borne coating compositions

These water borne coating compositions were applied on Melinex foil with a 40 μ draw bar. After drying at room temperature for 24 hours, gloss and transparency were measured. The results are provided in Table 3. Table 3: Water borne coating compositions applied on foil

In relation to commercially available water borne base coat toners containing the same pigmentation good gloss and transparency values are obtained.

Example 4

Use of pigment pastes in water and solvent borne coating compositions

Solvent borne coating compositions were prepared as shown in Table 4.

To measure the colour properties both water borne coating compositions from Table 2 and solvent borne coating compositions from Table 4 were mixed with commercially available white toners.

The water borne coating compositions were mixed with Autowave 099 ex Akzo Nobel in a 50:50 weight ratio, based on the amount of pigment in the coating compositions. Autowave Reducer was added to obtain a viscosity of the resulting coating composition of 25-30 seconds with DIN cup 4 at 20⁰C. The coating compositions were applied with a spray gun on pre-primed tin plates and dried at room temperature. A clear coat composition of Autoclear LV Ultra, Ultra Fast Hardener, and Ultra Thin (volume mixing ratio 3:1 :1 ) was sprayed on the dried base coat and cured at room temperature for 24 hours. The solvent borne coating compositions were mixed with Autobase Plus Q 110 ex Akzo Nobel in a 50:50 weight ratio, based on the amount of pigment in the coating compositions. Autobase Plus Reducer Medium was added to obtain a viscosity of the resulting coating composition of 16-18 seconds with DIN cup 4 at 20⁰C. The coating compositions were applied with a spray gun on pre-primed tin plates and dried at room temperature. A clear coat composition of Autoclear MS 2000, Autocryl Hardener MS 30, and 1.2.3 Thinner Fast (weight mixing ratio 100:50:9.65) was sprayed on the dried base coat and cured at room temperature for 24 hours.

The colour properties are listed in Tables 5 and 6.

It is shown that from one universal paste comprising the polyamine dispersant resin of the invention, water- as well as solvent borne coating compositions with excellent colour properties can be prepared.

Table 4: Solvent borne coating compositions

K)

O

Table 5: Water borne coating compositions white reductions colour properties.

Table 6: Solvent borne coating compositions white reductions colour properties.

Example 5

Use of higher-concentrated pigment pastes in water and solvent borne coating compositions

Pigment pastes comprising 37.5 wt.% and 40 wt.% Irgazin DPP Red BO were prepared in the same manner as Example 1. The formulations are listed in Table 7.

Table 7: pigment pastes

Example 6

Use of pigment pastes in water borne coating compositions

Water borne coating compositions were prepared as shown in Table 8. These water borne coating compositions were applied on foil as mentioned in Example 3. After drying, gloss and transparency were measured. The results are provided in Table 9.

Excellent gloss and transparency values are obtained.

Table 8: water borne coating compositions

Table 9: Water borne coating compositions applied on foil

Example 7

Use of pigment pastes in water and solvent borne coating compositions

Solvent borne coating compositions were prepared as shown in Table 10.

To measure the colour properties both water borne coating compositions from Table 8 and solvent borne coating compositions from Table 10 were mixed with commercially available white toners in the same manner as in Example 4. Coated panels were also prepared in the same manner as in Example 4. The results of the measurements are listed in Table 11.

Table 10: Solvent borne coating compositions

Table 11 : Water borne coating compositions white reductions colour properties.

Example 8

Use of the dispersant resin and pigment synergist for dispersing pigments

Pigment pastes were prepared with the polyamine dispersant resin of Example 1 , a blue pigment lrgalite Blue PG ex Ciba, and a pigment synergist chosen from Solsperse 5000 and Solsperse 12000 ex Noveon. The pastes were shaken with 600 g zirconox beads 1.2-1.7 mm on a Skandex machine for 1.5 hours, as mentioned in Example 2, except for pigment paste 20, which was shaken for 2 hours. The compositions of the pastes are summarized in Table 13 below. The figures are given in parts by weight.

Table 13: pigment pastes

Excellent pastes combining a very high pigmentation level and good fineness were obtained.

Example 9 Use of pigment pastes in water borne coating compositions

Water borne coating compositions were prepared as shown in Table 14. These water borne coating compositions were applied on foil as mentioned in Example 3. After drying, gloss and transparency were measured. The results are provided in Table 15.

Excellent gloss and transparency values were obtained.

Table 14: water borne coating compositions

Table 15: Water borne coating compositions applied on foil

Example 10

Use of pigment pastes in water and solvent borne coating compositions

Solvent borne coating compositions were prepared as shown in Table 16.

To measure the colour properties both water borne coating compositions from Table 14 and solvent borne coating compositions from Table 16 were mixed with commercially available white toners.

The water borne coating compositions were mixed with Autowave 099 ex Akzo Nobel in a 68:32 weight ratio, based on the amount of pigment in the coating compositions. With Autowave Reducer the resulting coating composition was set to spraying viscosity. The coating compositions were applied with a spray gun on pre-primed tin plates and dried at room temperature and treated further as mentioned in Example 4.

The solvent borne coating compositions were prepared, cured, and coated with a clear coat as mentioned in Example 4.

The colour properties are listed in Tables 17 and 18.

It is shown that from one universal paste comprising the polyamine dispersant resin of the invention, water- as well as solvent borne coating compositions can be prepared with excellent letdown properties, such as colour properties, absence of flocculation, and viscosity behaviour. Table 16: Solvent borne coating compositions

Table 17: Water borne coating compositions white reductions colour properties.

Claims

1. An amphiphilic polyamine dispersant resin having a polyamine backbone and pendent side groups, wherein the side groups comprise a) at least one side group substantially compatible with water linked to the polyamine backbone via a covalent bond, and b) at least one hydrophobic side group substantially compatible with at least one organic solvent .

2. The amphiphilic polyamine dispersant resin according to claim 1 , characterized in that the side group substantially compatible with water is a hydrophilic group, based on polyalkylene oxide.

3. The amphiphilic polyamine dispersant resin according to claim 2, characterized in that the polyalkylene oxide is based on ethylene oxide or a mixture of ethylene oxide and propylene oxide.

4. The amphiphilic polyamine dispersant resin according to any one of the preceding claims, characterized in that the side group substantially compatible with at least one organic solvent is based on polyesters, long- chain alcohols, or mixtures thereof.

5. The amphiphilic polyamine dispersant resin according to any one of the preceding claims, characterized in that the polyamine dispersant resin is prepared by reacting a) at least one di- or polyamine, b) at least one compound having at least one amine-reactive group and a pendent hydrophilic group, and, c) at least one compound having at least one amine-reactive group and a pendent hydrophobic group.

6. The amphiphilic polyamine dispersant resin according to claim 5, characterized in that compound (b) is obtained by the reaction of at least one compound having at least two isocyanate groups with a polyalkylene oxide based group having at least one isocyanate-reactive group selected from a compound according to formula (I) or (II), or a mixture thereof,

H₂N [(C₃H₆O)_n(C₂H₄O)Ri]-R₁ HO [(C₃H₆O)_n(C₂H₄O)Ri]-R₁

(I) (H)

wherein R¹ is selected from Ci to C₄ alkyl groups, n is O to 25, m is 1 to

50, and n+m < 50.

7. A composition comprising the polyamine dispersant resin according to any one of preceding claims 1 to 6 and a pigment.

8. A composition according to claim 7, characterized in that the composition is liquid.

9. A process for preparation of a liquid pigment concentrate comprising subjecting to shear force a liquid mixture comprising a pigment, at least one dispersing agent, and optionally a liquid diluent, characterized in that the polyamine dispersant resin according to any one of the preceding claims 1 to 6 is used as dispersing agent.

10. A process according to claim 9, characterized in that the liquid diluent is water.

11. A coating composition comprising at least one organic film forming binder, at least one pigment, and a pigment dispersant resin, characterized in that the pigment dispersant resin is a polyamine dispersant resin according to any one of preceding claims 1 to 6.