AU619199B2 - Coating compositions and process for manufacturing a multilayer protective and/or decorative coat on the surface of a substrate - Google Patents

Description

9 AU-AI-20718/88 WELTORGANISATION FOR GEISTIGES EIGENTUM Internationales Blro TER ATIONALE ANMELDUNG VEROFFENTLICHT NACH DEM VERTRAG OBER DIE INTERNATIONALE ZUSAMMENARBEIT AUF DEM GEBIET DES PATENTWESENS (PCT) (51) Internationale Patentklassifikation 4 (11) Internationale Verbiffentlichungsnummer: WO 89/ 01004 CO8G 18/10, 18/32, 18/38 Al (43) Internationales 5/06, CO9D 3/72 Verffentlichungsdatum: 9. Februar 1989 (09.02.89) (21) Internationales Aktenzeichen: PCT/EP88/00650 (81) Bestimmungsstaaten: AT (europiiisches Patent), AU, BE (europdisches Patent), BR, CH (europiisches Pa- (22) Internationales Anmeldedatum: 19. Juli 1988 (19.07.88) tent), DE (europiisches Patent), FR (europdisches Patent), GB (europiiisches Patent), IT (europhisches Patent), JP, LU. (europisches Patent), NL (europtisches (31) Prioritiitsaktenzeichen: P 37 25 784.6 Patent), SE (europiisches Patent), US.

(32) Priorititsdatum: 4. August 1987 (04.08.87) Veriffentlicht (33) Priorititsland: DE Mit internationalem Recherchenbericht.

(71) Anmelder (fiar alle Bestimmungsstaaten ausser US): BASF LACKE FARBEN AKTIENGESELL- SCHAFT [DE/DE]; Max-Winkelmann-Strage 80, D- 4400 Miinster 20 APR 1989 (72) Erfinder;und Erfinder/Anmelder (nurfiir US) HILLE, Hans-Dieter [DE/DE]; In der Schlade 24, D-5060 Bergisch-Glad-

AUSTRALIAN

bach DOBBELSTEIN, Arnold [DE/DE]; Elmil- AN Nolde-Weg 95, D-4400 MOnster GROSCH, mA 1989 Horst [DE/DE]; Am Anger 17, D-8702 Leinach O PATENT OFFICE (54) Title: COATING COMPOSITIONS AND PROCESS FOR MANUFACTURING A MULTILAYER PROTECTI- VE AND/OR DECORATIVE COAT ON THE SURFACE OF A SUBSTRATE 1 1 (54) Bezeichnung: BESCHICHTUNGSZUSAMMENSETZUNGEN UND VERFAHREN ZUR HERSTELLUNG El- NES MEHRSCHICHTIGEN, SCHOTZENDEN UND/ODER DEKORATIVEN OBERZUGES AUF EINER SUBSTRATOBERFLACHE (57) Abstract Coating compositions particularly suited to the manufacture of the base coat of two-layer varnishes of the base coat/ clear coat type contain organic solvents, at least one synthetic resin containing urethane and urea groups, possibly other synthetic resins, pigments and other ordinary additives. These coating compositions are characterized in that they contain at least one synthetic resin which contains urethane and urea groups obtained by converting al) a compound containing hydroxyl groups capable of reacting with isocyanate groups and a2) an aliphatic and/or cycloaliphatic diisocyanate to a prepolymer containing isocyanate groups and then converting at least some of the isocyanate groups of prepolymer with a3) at least an additive containing an active amine hydrogen atom produced from a (meth)acrylic acid ester, preferably acrylic acid ester, and at least one aliphatic or cycloaliphatic compound containing two amine hydrogen atoms.

(57) Zusammenfassung Die Erfindung betrifft Beschichtungszusammensetzungen, die insbesondere zur Herstellung der Basisschicht von Zweischichtlackierungen des Basecoat/Clearcoat-Typs geeignet sind und die organische Verdiinnungsmittel, mindestens ein Urethan- und Harnstoffgruppen enthaltendes Kunstharz, ggf. weitere Kunstharze, Pigmente und sonstige allgemein ibliche Zusatzstoffe enthalten. Die erfindungsgema8en Beschichtungszusammensetzungen sind dadurch gekennzeichnet, daR sie mindestens ein Ureian- und.Harnstoffgruppen enthaltendes Kunstharz enthalten, das erhiltlich ist, indem al) eine Verbindung, die zwei gegentiber Isocyanatgruppen reaktive Hydroxylgruppen tragt und a2) ein aliphatisches und/oder cycloaliphatisches Diisocyanat zu einem isocyanatgruppenhaltigen Praipolymeren umgesetzt werden und die Isocyanatgruppen des Prdpolymeren anschlieBend zumindest zum Teil mit a3) einem mindestens ein aktives Aminwasserstoffatom enthaltenden Addukt aus einem (Meth)acryldiureester, vorzugsweise Acrylsdureester, und einer mindestens zwei Aminwasserstoffatome enthaltenden aliphatischen oder cycloaliphatischen Verbindung umgesetzt werden.

p: PAT 87 131 24.07.1987 BASF Lacke Farben AG, Munster Coating compositions and process for the preparation of a multicoat protective and/or decorative coating on a substrate surface The invention relates to coating compositions which are particularly suitable for the preparation of the basecoat for two-coat coatings of the basecoat/clearcoat type, and which comprise organic diluents, at least one resin containing urethane and urea groups, and, where appropriate, other resins, pigments and other conventional additives in common use.

In the field of automotive finishing in particular, but also in other areas there is considerable interest in S basecoat compositions for the preparation of multicoat S 15 coatings.

In automotive finishing, two-coat coatings of the basecoat/clearcoat type in particular have gained wide accep- Stance, especially for metallic finishes.

Basecoat/clearcoat coatings are prepared by first applying a pigmented basecoat which, after a brief flush-off period, is overcoated by a clearcoat without a baking stage (wet-on-wet process), the basecoat and clearcoat being subsequently baked together.

A The coating compositions for the preparation of these basecoats must be capable of being processed by the expedient wet-on-wet process, in general use today, i.e.

they must be capable, after an as short a drying time as possible without a baking stage, of being overcoated with a transparent topcoat, without the appearance of any defects due to solvent action of one coat on the other and of any "strike-in" phenomena.

2 In addition, other problems must be solved in the development of coating compositions for basecoats for metallic finishes. The metallic effect depends crucially on the orientation of the metallic pigment particles in the paint film. A basecoat for metallic finishes, capable of being processed by the'wet-on-wet process, must therefore produce paint films in which the metallic pigments are present after the application in a suitable spatial orientation and in which this orientation becomes rapidly set in such a way that it cannot be disturbed in the course of further painting processes.

EP-A-137,256 discloses coating compositions for the prete paration of the basecoat for two-coat coatings of the Sbasecoat/clearcoat type which contain polyurethane elas- 15 tomers and/or polyurea elastomers as binder components.

From the coating compositions disclosed in EP-A-137,256 it is possible to prepare two-coat coatings, in particular two-coat metallic coatings which possess a good metallic effect, good adhesion and excellent resistance to stone impact.

o* 00 More recently, automotive manufacturers have gone over to using two-component clearcoats based on polyisocyanates Sfor refinishing. These clearcoats are cured at room temperature or at temperatures not exceeding 80 0

C.

When the coating compositions disclosed in EP-A-137,256 Saiie used for the preparation of the basecoat, color differences appear between the original finish baked at 140 0 C and the refinish carried out using the two-component clearcoats.

The object of the present invention was to make available coating compositions for the preparation of the basecoat for two-coat coatings of the basecoat/clearcoat type which would be free from the shortcomings referred to above.

3 According to the present invention there is provided a process for the preparation of a multicoat protective and/or decorative coating on a substrate surface comprising applying a coating composition which comprises organic diluents, at least one resin containing urethane and urea groups, and pigments to the substrate as a basecoat composition, forming a polymeric film on the substrate surface from the basecoat composition applied in stage 1Q applying a suitable transparent topcoat composition to the basecoat obtained in this manner, and subsequently ref baking the basecoat and the topcoat together, wherein the basecoat composition resin is obtainable by reacting U 0tt al) a compound having two hydroxyl groups .ct reactive toward isocyanate groups, with a 2) an aliphatic and/or cycloaliphatic diisocyanate to form a prepolymer containing isocyanate groups, and by subsequently reacting the isocyanate groups of prepolymer at least in part, with a3) an adduct produced from a methacrylic or acrylic ester, and an aliphatic or cycloaliphatic compound containing at least two aminic hydrogen atoms, the adduct containing at least one active I aminic hydrogen atom.

3A- The benefits achieved by the invention consist essentially in the absence of any colour differences between the original finish and the refinish when the coating compositions according to the invention are used. A further important benefit is that the resins containing urethane and urea groups, used in the basecoat compositions according to the invention, may be prepared by using an a3) component containing hydroxyl groups and then converted to satisfactory basecoats even without the addition of polyol components. It is furthermore possible to incorporate in the resin molecule hard polyester segments without producing incompatibility phenomena when aminoplast resins are added.

I Apart from these benefits, the coating compositions according to the invention also possess the advantages of the coating S1S,,, compositions disclosed in EP-A-137,256.

I t The resins containing urethane and urea groups, contained---7 C C t tW 4 4 4 -4in the coating compositions according to the invention, are obtainable by reacting al) a compound having two hydroxyl groups reactive toward isocyanate groups, with a2) an aliphatic and/or cycloaliphatic di-isocyanate to form a prepolymer containing isocyanate groups, and by subsequently reacting the isocyanate groups of the prepolymer at least in part, with a3) an adduct produced from a (meth)acryLic ester, preferably an acrylic ester, and an aliphatic or cycloaliphatic compound containing at least two aminic hydrogen atoms, the adduct containing at least one Si.. active aminic hydrogen atom.

Any diat which is suitable for the preparation of polyurethane paint resins, may in principle be used as the component al). These diots may be low-moleoular, but diols with a higher molecular weight may also be used. Examples of low-molecular diols are ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butane dioL, neopenty glycol and hexane-1,6-dio.

ete dCl an poyse dils Examples of dioLts with a higher molecular weight are polyether diots and poLyester diots.

Suitable polyether diots are poly(oxyalkylene) diols such as, for example, poly(oxytetramethyene) glycoL, poly(aoxyethylene) glycol, poly(oxypropylene) glycoL etc.

Polyester diots are preferably used as the component al).

These polyester dioLts are obtainable by esterifying organic dicarboxylic acids or their anhydrides with organic diots. Diols which are customarily used for thenpreparation of these polyesters, comprise alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, 1 hexyene glycol, and neopentyl glycol, as well as other @1 ft

I

5 glycols, such as hydrogenated bisphenol-A, cyclohexanedimethanol, caprolactone diol (for example the reaction product of E-caprolactone and ethylene glycol), hydroxyalkylated bisphenols, polyether glycols, for example poly(oxytetramethylene)glycol and the like. Other dioLs may, however, also be used.

The acid component of the polyester diols usually consists of dicarboxylic acids or their anhydrides having 2 to 18 carbon atoms per molecule. Examples of suitable acids are phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, glutaric acid, hexachloroheptenedicarboxylic acid, tetrachlorophthalic acid and other dicarboxylic acids of vari- 15 ous types. The corresponding anhydrides may of course also be used in place of the acids.

Those polyester diols which contain isophthalic acid as the acid component and have an average molecular weight (number average) of 400 to 2,000, are particularly pre- 20 ferred as the component al).

Mixtures of various diols for example mixtures of a polyester diol and a low-molecular diol may of course also be used as the component al).

Any aliphatic and/or cycloaliphatic diisocyanate which is suitable for the preparation of polyurethane paint resins, may in principle be used as the component a2). There are many such di-isocyanates. Examples of suitable di-isocyanates are 1,4-tetramethylenedi-isocyanate, hexamethylenedi-isocyanate, 2,2,4-tr iethylhexane-1,6-di-isocyanate, isophoronedi-isocyanate, bis(isocyanatocyclohexyl)methane and methyl-cyclohexyldi-isocyanate.

Mixtures of various di-isocyanates may of course also be X used.

t r I;t C 6 Adducts produced from (meth)acrylic esters and aliphatic and/or cycloaliphatic compounds containing at Least two aminic hydrogen atoms, are used as the component a3).

These adducts must contain at Least one aminic hydrogen atom reactive toward isocyanate groups (a so-called active aminic hydrogen atom). The number of the active aminic hydrogen atoms must be selected so that no crosslinked resins are obtained. Adducts with 1 to 3 active aminic hydrogen atoms are in general used as the component a3).

Adducts with two active aminic hydrogen atoms are preferably used.

The preparation of the adducts employed as the component a3) is carried out in a simple manner by reacting an aliphatic and/or cycloaliphatic compound containing at least 9 15 two aminic hydrogen atoms, with (meth)acrylic esters.

The addition reaction may be performed in the molten state or in solution at temperatures between 20 and 120 0 C, preferably below 50°C. The reaction is in the majority of cases exothermic. The adducts used as the component a3) are advantagously prepared by dissolving the compound containing at least two aminic hydrogen atoms in a suitable S solvent and gradually adding the (meth)acrylic ester with i stirring at such a rate that the reaction temperature does not exceed 9 25 Methacrylic esters as well as acrylic esters may be used for the preparation of the component a3). Acrylic esters are lreferably used. Examples of suitable (meth)acrylic S esters are ethyl(meth)acrylate, methyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate and 2-ethylhexyl(meth)acrylate.

(Methy)acrylic esters containing hydroxyl groups, particularly alkyl(meth)acrylates containing hydroxyl groups, are preferably used. Alkyl (meth)acrylates containing hydroxyl groups whose alcoholic component has at least 4 carbon atoms, are most particularly preferred. Examples S\ of suitable alkyl(meth)acrylates containing hydroxyl ii -7 groups are 2-hydroxyethyl (meth)acryLate, 2-hydroxypropyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate as well as in particular a reaction product of one mot of a hydroxyalkyl (meth)acrylate, preferably a hydroxyaLkyl acrylate, particularly hydroxyethyl acrylate, with 1 to 3, preferably 2 mot of e-caproLactone.

The component a3) is prepared by reacting the (meth)acry- Lic esters described above with a compound containing at least two aminic hydrogen atoms. To this purpose the reaction conditions and the type and amount of the compound containing at least two aminic hydrogen atoms must be so selected that the resultant adduct contains at least one, preferably 1 to 3 active aminic hydrogen atoms.

t *tt Suitable compounds containing at least two aminic hydrogen

I

15 atoms are, for example, ethylenediamine, 1,2- or 1,3-propye lenediamine, 1,6-hexanediamine, 2-methyl-1,6-hexanediamine, 1-methyl-2,4-diaminocyclohexane, 1-amino-3-aminomethyl- 3,5,5-trimethylcyclohexane, 1,3- or 1,4-bisaminomethylcyclohexane or 4,4'-diaminodicyclohexylmethane. Compounds which contain primary amino groups, are preferred.

i The resin containing urethane and urea groups, contained Sin the coating compostions according to the invention, is advantageously prepared by first reacting the components al) and a2) to form a prepolymer containing isocyanate groups. This reaction may be carried out by wellknown metk't of polyurethane chemistry. The reaction between the components al) and a2) is preferably carried out in an .i inert organic solvent (for example toluene, xylene, ethyl acetate or butyl acetate). In addition, the amounts of the components al) and a2) chosen for the reaction are preferably such that the molar ratio of al) to a2) is 0.5:1.0 to 0.9:1.0.

The adduct a3) is prepared in a separate reaction vessel

SU

L

4 in the manner described above. The final preparation of the resin according to the invention may be then carried 8 out by a slow addition of the prepolymer to the adduct a3). The proportion of the amount of prepolymer (A) to that of the component a3) is preferably so chosen that 1 to 2 active aminic hydrogen atoms are present per one isocyanate group.

A coating composition which is suitable as a basecoat composition for basecoat/clearcoat coatings, may be prepared from the resin containing urethane and urea groups according to the invention, described above, by generally known methods. The coating compositions according to the invention contain in addition to the resin according to the invention customary organic diluents, other resins where appropriate, pigments and other conventional addir Stives ii. common use.

t' 15 The organic diluents contained in the coating compositions according to the invention can consist of volatile organic liquids or mixtures of liquids, normally employed in coating compositions as polymer solvents or polymer dispersants.

Suitable examples of these are: aliphatic hydrocarbons, for example hexane and heptane, aromatic hydrocarbons, such as, for example, toluene and xylene, and petroleum fractions with various ranges of boiling points, which are mainly aliphatic but may also comprise a substantial aromatic content, esters, for example butyl acetate, ethylene glycol diacetate and 2-ethoxyethyl acetate, ketones, for example acetone and methyl isobutyl ketone, and alcohols, for example butyl alcohol.

Examples of resins which may be contained in the coating compositions according to the invention in addition to the resin according to the invention, are polyesters described in EP-A-137,256.

The coating compositions according to the invention advant- Sageously contain a crosslinking agent. Suitable crosslinking 9 agents are, for example, aminoplast resins, phenolic resins or blocked polyisocyanates. Aminoplast resins such as condensation products of formaldehyde with meLamine, urea or benzoguanamine, are preferred. These aminoplast resins frequently contain methyLol groups or similar alkylol groups which are preferably at least partly etherified with an alcohol.

The coating compositions according to the invention preferably contain 40 to 80% by weight, particularly preferably 55 to 65% by weight, based on the binder solids, of the resin according to the invention containing urethane and urea groups.

t r e The coating compositions according to the invention may contain any pigment which is suitable for a basecoat/ *r 15 clearcoat coating. Coating compositions which contain ec~L metal platelet pigments, preferably aluminum platelets, e either individually or in admixture, are particularly preferred. In addition to the metal platelet pigment, the preferred coating compositions may contain further colorant non-metallic pigments.

The coating compositions according to the invention may also contain further customary additives such as fillers, ac. plasticizers, stabilizers, wetting agents, dispersants, S .rf oflow-o.ut agents, antifoams and catalysts either individually or in admixture in the customary amounts.

co cTo improve further the metallic effect, crosslinked polymeric microparticles and/or a copolymer prepared from to 95% by weight of ethylene and 15 to 5% by weight of vinyl acetate, may be added to the coating compositions according to the invention. Suitable polymeric microparticles are for example those described in EP 29,637 A2.

LIA 4 The invention further relates to a process for the prei paration of a multicoat protective and/or decorative 10 coating on a substrate surface in which a coating composition which comprises organic diluents, at least one resin containing urethane and urea groups, pigments and, where appropriate, other resins and other conventional additives in common use, is applied as basecoat composition, a polymeric film forms on the substrate surface from the coating composition applied in stage a suitable transparent topcoat composition is applied to the basecoat obtained in this manner, and subsequently the basecoat and the topcoat are baked together, Swherein the basecoat composition comprises at least one Sresin containing urethane and urea groups, the resin being obtainable by reacting str al) a compoud having two hydroxyl groups reactive toward isocyanzte groups, with a2) an aliphatic and/or cycloaliphatic di-isocyanate I cc to form a prepolymer containing isocyanate groups, 20 and by subsequently reacting the isocyanate groups of the prepolymer at least in part, with ra3) an adduct produced from a (meth)acrylic ester, pref- C t erably an acrylic ester, and an aliphatic or cycloaLiphatic compound containing at least two aminic hydrogen atoms, the adduct containing at least one active aminic hydrogen atom.

In the first stage of the process according to the invention, a coating composition, as described above, is applied as basecoat composition. After a brief flash-off period, the resultant basecoat is overcoated by a transparent topcoat composition without a baking stage (wet-onwet process). The basecoat and topcoat are finally baked Stogether.

11 Basically any known non-pigmented or only transparently pigmented coating compositions are suitable as topcoat compositions. These may be conventional solventcontaining clearcoats, water-dilutable clearcoats or powder clearcoats.

Pretreated metal substrates are particularly suitable as the substrates to be coated, but non-pretreated metals and any other substrates, such as, for example, wood and plastics, may be coated by a basecoat/clearcoat coating by the process according to the invention.

The invention also relates to a substrate which has been coated by the process described above.

fI t 4 4 *W*4 1 The invention also relates to resins containing urethane and urea groups which are obtainable by reacting 15 al) a compound having two hydroxyl groups reactive toward isocyanate groups, with a2) an aliphatic andeor cycloaliphatic dissocyanate to form a prepolymer containing isocyanate groups, and by subsequently reacting the isocyanate groups of the pre- 20 polymer at least in part, with a3) an adduct produced from a (meth)acrylic ester, preferably an acrylic ester, and an aliphatic or cycloaliphatic compound containing at least two aminic hydrogen atoms, the adduct containing at least one active aminic hydrogen atom.

A. t The invention is explained in further detail in the examples below. ALL parts and percentages are parts and percentages by weight, unless expressly stated otherwise.

'3A ,1 1 E 12 1. Preparation of a compound comprising two hydroxyl groups reactive toward isocyanate groups (component al) 1682 g of 2,2-dimethyLpropane-1,3-dioL, 472 g of adipic acid, 479 g of phthalicanhydride and 1074 g of isophthalic acid are weighed into a 6-Liter fournecked fLask provided with a stirrer, a thermometer, a packed coLumn having a thermometer at its head, a distillation bridge, a descending condenser and a condensate receiver. The reaction mixture is first heated to 160 0 C with stirring. After water has begun to split off, the temperature is so controlled that the temperature at the head of the column does not exceed 100 0 C. Esterification is continued at a f 15 temperature of 230°C max., until the acid value is The resultant polyester has a hydroxyl value Sof 118. The polyester is dissolved in butyl acetate to give an 80% solution.

2. Preparation of a prepolyri,;r containing isocyanate groups r ,1580 g of the polyester solution prepared according to the instructions under item 1, 17 g of 2,2-dimethylpropane-1,3-diol, 60 g of diethylene glycol and 72 g of butyl acetate are weighed into a four-necked flask provided with a stirrer, a thermometer and a reflux conienser, and the reaction mixture is heated to 60 0

C.

S859 g of 4,4-dicyclohexylmethane di-isocyanate are then added in the course of 10 minutes. When the re- L action mixture has become homogeneous, 0.8 g of dibutyltin dilaurate is added. The temperature is now increased to 100 0 C and maintained for 3 hours.

A prepolymer with an NCO content of 3.75% is obtained.

j L *r 4j 13 3. Preparation of acrylic ester amine adducts (component a3) 3.1 476 g of 4,4'-diamino-3,3-dimethyldicyclohexyLmethane (Laromin C 260 ex BASF AG) is introduced in a twoliter vessel which can be cooled and which is provided with a stirrer, reflux condenser, a thermometer and an inlet vessel. 562 g of 4-hydroxybutyl acrylate are added from the inlet vessel in the course of 3 hours with stirring, during which time the reaction temperature is maintained below 50 0 C by cooling.

When the addition is completed, stirring is continued at room temperature. A faintly yellowish clear vist cous liquid is obtained.

3.2 357 g of 4,4'-diamino-3,3'-dimethyldicyclohexylmethane 15 (Laromin C 260 ex BASF AG) are introduced in the apt r paratus described in procedure 3.1; 903 g of a ret action product of one mol of hydroxyethyl acrylate with two mol of e-caprolactone (TGne M-100 ex UCC) are added dropwise from the inlet vessel in the course of 3.5 hours with stirring. The reaction temperature cr fis maintained below 50 0 C by cooling. When the addition is completed, stirring is continued for 3 hours at room temperature. A faintly yellowish vis- Sf cous liquid with an amine value of 131 is obtained.

3.3 The procedure 3.2 is followed, but instead of 903 g of Tone M-100, 516 g of Tone M-100 are added. The Sreaction product has an amine value of 191.

4. Preparation of resins according to the invention containing urethane and urea groups 4.1 A mixture consisting of 392 g of the adduct from procedure 3.1, 2077 g o butyl acetate and 744 g of n-butanol is prepared in a vessel provided with a IiV stirrer. 1040 g of the prepolymer from procedure 2 are added to this mixture in the course of 20 minutes 14 with stirring. An almost colorless solution is obtained with a solids content of 30% by weight and a viscosity of 3.4 dPas.

4.2 A mixture consisting of 189 g of the adduct from procedure 3.3, 1010 g of butyl acetate and 362 g of n-butanol is prepared in a vessel provided with a stirrer. 507 g of the prepolymer from procedure 2 are added to this mixture in the course of 20 minutes with stirring. An almost colorless solution is obtained with a solids content of 30% by weight and a viscosity of 4.0 dPas.

Sr 4.3 A mixture consisting of 343 g of the adduct from pro- I cedure 3.2, 1304 g of butyl acetate and 521 g of n-butanol is prepared in a vessel provided with a c 15 stirrer. 648 g of the prepolymer from procedure 2 I are added to this-mixture in the course of 20 minutes Sc t with stirring. A clear, colorless solution is obtained with a solids content of 30% and a viscosity of 3 dPas.

5. Preparation of basecoat compositions according to the Sinvention 23 parts of the copolymer dispersion described in Example D of EP-A-137,256 are blended with 47 parts of the resin solution prepared by procedures 4.1, 4.2 or 4.3 and with 13 parts of melamine resin etherified with butanol (Maprenal MF 650 ex Hoechst AG) to form a homogeneous mixture. Subsequently 5.5 parts of aluminum platelet pigment paste (65% in aliphatic hydrocarbons), triturated with 11.5 parts of butyl acetate, are incorporated in the above mixture. The viscosity of the resultant mixture is adjusted to 24 seconds (ISO 4) (spraying viscosity) with a mixture of 50 parts of butyl acetate, 25 parts of butyl- 4' glycol acetate and 25 parts of n-butanol. The solids S/ 35 content of .the basecoat compositions is 20% by weight.

II

15 6. Clearcoats used for the preparation of two-coat coatings of the basecoat/clearcoat type 6.1 Factory-finish clearcoat The clearcoat described in Examples K1 and K2 of EP-A-137,256 was used as the factory-finish clearcoat.

6.2 Refinish clearcoat The composition described in Example K2 of EP-A-137, 256 has been taken over except that instead of the melamine resin, 163 g of a hexamethylene di-isocyanate trimerized via the biuret groups, marketed by Bayer SAG under the trade name DESMODUR N, has been used.

The solids content is 49.5%. This 2-component J clearcoat has only a limited shelflife and should be iused up soon after preparation.

7. Preparation of two-coat coatings of the basecoat/ clearcoat type 7.1 Automotive body panels coated with a conventional t Ci primer and a filler coat are sprayed with the basecoat compositions prepared by procedure 5, using a cA 20 flow-cup spraygun, in such a manner that a dry film thickness of the basecoat of 12 to 17 4m is obtained.

After a flash-off period of 5 minutes, the sprayed basecoats are overcoated with the factory-finish cLearcoat and the refinished clearcoat in such a manner that a dry film thickness of the clearcoat of 35 to um is obtained. After a flash-off period of minutes, the coatings produced with the factory-finish clearcoat are baked for 20 minutes at 140°C and those produced with the refinish clearcoat are baked for 20 minutes at 80 0

C.

"*a i 16 7.2 (Comparison example) The process described in procedure 7.1 is carried out, but the coating composition disclosed in Example 3 of EP-A-137,256 is used as the basecoat composition.

8. Assessment of the two-coat coatings prepared by procedure 7 8.1 In order to assess the two-coat coatings prepared by procedure 7, the metallic effect of the coatings is measured and calculated in the following manner: Instrument: goniophotometer GP2 (CARL ZEISS) The measurement of the brightness viewed directly and viewed obliquely is carried out against a calibrated reference.

i* p 0*fl 0 *0 0 *004 *4 t Measurement of the Single-beam angle: Observation angle: Measurement of the Single-beam angle: Observation angle: brightness viewed directly (BD): -450 aperture 0.250 380, aperture 0.250 brightness viewed obliquely (BO): -700, aperture 00, aperture ;rC RVS x 62

RVR

RVS x

RVR

RVS read-out value of sample RVR read-out value of reference 17 A marked metallic effect is observed when the BD value is high and the BO value is low. A measure of the metallic effect is obtained from the formula: ME BD x 100

BO

8.2 Measurement results Factory-finish Refinish clearcoat clearcoat Basecoat composition 1 113* 117* Basecoat composition 2 129* 125* Basecoat composition 3 113* 117* Comparison example 78* 53* The differences between the factory-finish coatings and the refinish coatings are distinctly less when the basecoat compositions according to the invention are used than when basecoat compositions according to EP-A-137,256 are used.

ME values determined by procedure 8.1 q i

I

S*

0s S

I

4 *s s

Claims (9)

1. A process for the preparation of a multicoat protective and/or decorative coating on a substrate surface comprising applying a coating composition which comprises organic diluents, at least one resin containing urethane and urea groups, and pigments to the substrate as a basecoat composition, forming a polymeric film on the substrate surface from the basecoat composition applied in stage applying a suitable transparent topcoat composition to the basecoat obtained in this manner, and ,*00 subsequently c* 0 baking the basecoat and the topcoat together, wherein the basecoat composition resin is obtainable by reacting 006 al) a compound having two hydroxyl groups reactive toward isocyanate groups, with 0 a2) an aliphatic and/or cycloaliphatic di- isocyanate S* to form a prepolymer containing isocyanate groups, and by subsequently reacting the isocyanate groups of prepolymer at least in part, with a3) an adduct produced from a methacrylic or acrylic ester, and an aliphatic or cycloaliphatic compound containing at Sleast two aminic hydrogen atoms, the SKadduct containing at least one active 19 aminic hydrogen atom.

2. A process as claimed in claim 1 in which the adduct of a3) is produced by an acrylic ester.

3. A process as claimed in claim 1 or 2 in which the basecoat composition further comprises other resins and other conventional additives in common use.

4. A process as claimed in any preceding claim in which a polyester diol, prepared from isophthalic acid, having an average molecular weight (number average) of 400 to 2,000, is used as the component al). S 5. A process as claimed in any preceding claim in which the components al) and a2) are used in a molar ratio of 0.5:1.0 to 0.9:1.0. *o

6. A process according to any one of claims 1 to 5, in which the adduct used as component a3) contains two active aminic hydrogen atoms per molecule. 9

7. A process according to any one of claims 1 to 6, in which the basecoat composition contains metallic platelet pigments. 0 26 8. A substrate, coated with a multicoat protective and/or decorative coating, produced by the process of any one of claims 1 to 7.

9. The use of a multicoat protective and/or decorative coating on a substrate surface in accordance with the process of any one of claims 1 to 7. A process for the preparation of a multicoat protective and/or decorative coating on a substrate surface I substantially as hereinbefore described with reference to any one of the foregoing examples. 20

11. A substrate, coated with a multicoat protective and/or decorative coating substantially as hereinbefore described with reference to any one of the foregoing examples. Dated this 30th day of October, 1991 BASF LACKE FARBEN AG By its Patent Attorneys: GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. t E4 it i t I t i; t 1 te t t rr t t H t t ttt. t t I. If i c: I Coating compositions and process for the preparation of a multicoat protective and/or decorative coating on a substrate surface Abstract The invention relates to coating compositions which are particuLarLy suitable for the preparation of the basecoat for two-coat coatings of the basecoat/clearcoat type, and which comprise organic diluents, at least one resin con- taining urethane and urea groups, and, where appropriate, other resins, pigments and other conventional additives in common use. The coating compositions according to the invention are those which comprise at least one resin con- Staining urethane and urea groups, whirh resin is obtain- able by reacting t e Si- al) a compound having two hydroxyl groups reactive toward isocyanate groups, with a2) an aliphatic and/or cycloaliphatic di-isocyanate to form a prepolymer containing isocyanate groups, I and by subsequently reacting the isocyanate groups of the Sprepolymer at least in part, with a3) an adduct produced from a (meth)acrylic ester, pref- erably an acrylic ester, and an aliphatic or cyclo- aliphatic compound containing at least two aminic hydrogen atoms, the adduct containing at least one active aminic hydrogen atom. I INTERNATIONAL SEARCH REPORT International Application No PCT/EP 88/00650 I. CLASSIFICATION OF SUBJECT MATTER (If several classification symbols apply, Indicate all) According to International Patent Classification (IPC) or to both National Classification and IPC C 0 8 G 18/10; Int. C1. C 08 G 18/32; C 08 G 18/38; B 05 D 5/06; C 09 D 3/72 II. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols Int. Cl. 4 C 08 G; B 05 D Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included In the Fields Searched Ill. DOCUMENTS CONSIDERED TO BE RELEVANT' Category I Citation of Document, i with indication, where appropriate, of the relevant passages 12 i Relevant to Claim No. 13 X DE, A, 2158945 HOLFORT) 30 May 1973, see 1,5,8,9, claims 1,8,9,11,12,18,21; page 5, last paragraph page 6, last paragraph; page 9, paragraph 2; page 16, paragraphs 3,4; page 18, paragraph 2; page 19, paragraph 2 A EP, A, 0046088 (MITSUI-TEXACO) 17 February 1,8,9 1982, see claims 1-3,10; page lines 1-24 Special categories of cited documents: lo later document published after the International filing date document defining the general state of the art which Is not or priority date and not in conflict with the application but considered to be of particular relevance cited to understand the principle or theory underlying the invention ealier document but published on or after the international d ment of pic r i filing date X" document of particular relevance; the claimed invention cannot be considered novel or cannot be considered to document which may throw doubts on priority claim(s) or Involve an inventive step which is cited to establish the publication date of another d o citation or other special reason (as specified) document of particular relevance: the claimed Invention itio o o s ia r s ifie cannot be considered to involve an Inventive step when the document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other means ments, such combination being obvious to a person skilled document published prior to the international filing date but in the art. later than the priority date claimed document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report 29 September 1988 (29.09.88) 14 October 1988 (14.10.88) International Searching Authority Signature of Authorized Officer European Patent Office Form PCT/ISA/210 (second sheet) (January 1985) A- ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. EP 8800650 SA 23217 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members are as contained in the European Patent Office EDP file on 06/10/88 The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent document Publication Patent family Publication cited in search report date member(s) date DE-A- 2158945 30-05-73 Keine EP-A- 0046088 11-02-82 JP-A- 57036115 26-02-82 AU-A- 7401081 18-02-82 US-A- 4431790 14-02-84 CA-A- 1169089 12-06-84 AU-B- 547172 10-10-85 s o •3 For more details about this annex see Official Journal of the European Patent Office, No. 12/82 INTERNATIONALER RF.CHERCHENBERICHT Internatioialea Aktenzeichen PCT/ EP 88 /00650 1. KILASSIFIKATION DES ANMELDUNGSGEGENSTANOS (bel merhreren Klassifikationssymbolen sind aile anzugebelk 8 N-ach dr Internationalen Paten tk lassifi katio n (Ipc) o.jer nach der nationalen Kiassifikation und der IPC C 08 G 18 /10 In,.ClA4. C 08 G 18/32; C 08 G 18/38; B 05 D 5/06; C 09 D 3/72 I1. RECI4EICHIERTE SACHGESIETS Reclierchierter Mindlestpriifstoff 7 Klassifikationssystem K lassi fikationssymbole Recherchierte nicht zumn Mindlestpri~fstoff gehorende Verdf-fend ichungen, soweit diese unter die recherchierten Sachgebiete fallen 8 III.EINSCHLAGIGE VEROFFENTLICHUNGEN 9 Art. Kennzeichnung der Verolfentlichungll t soweit erforderlich unter Angabe der maggeblich~n TeiHI 2 F eer. Anspruch Nr. 1 K DE,A, 2158945 HOLFORT) 30. Mai 1973, siehe 1,5,8,9, nga rtArspriiche 1,8,9,11,12,18,21; Seite iiette Ab-§atz Seite 6 letz ter AbMatz; 0V'zS e It e Absatz 2; Seite' 16L Absd.tze 3,4; Seite 18, Absatz 2; Seite 19, Absatz 2 A EP, A, 0046088 (MITSUI-TEXACO) 17. Februar 1982, 1,8,9 siehe Anspriiche 1-3,10; Seite 20, Zeilen 1-24 *Besondere Kategorien von angegebenen Ver~ffentlichungen 1 Veroffentlichung, die den ailgemneinen Stand der Technik Spatere Ver6ffentlichung, die nach dem internationalen An- definiert. aber nicht als besonders bedeutsam anzusehen ist meldedlatumn oder dem Priorit~tsdatum veroffentlicht warden it und mit der Anmeldlung nicht kollidiert, tandern nur zum 9iteres Dokcument, dlas jedloch erst am oder nach dem interna- Verstandnis des der Erfindlung zugrundeliegenden Prinzips tionalen Animeldeclatumn verbffentlicht worden ist oder der 1hr zugrundeliegenden Theorie angegeben it Verdfentiichung, die geeignet aSt, einen Prioritatsanspruch "X eofnlcugvnbsnerrBduug i enpuh zfeihugaftu rc ine z asseni odedurchendie h a e- te Er-findung kann nicht als neu oder auf erfinderischer Tatig. ferntihngsdasu enlhnr anee mceceberict keit beruhend betrachtet werden narrten'~rdfenlichn egt werden soil oder die aus eulnr anderen besonderen Grund angegeben ist (We ausgefuhrt) Veroffentlichung von besonderer Bedleutung; die beenspruch- erdentlchug, de sch uf ene ~ndlcheOffebarng, te Erfindung kann nicht als aut erfinderischer Titigiceit be- e Veaentiung, ine Asich auene mdor ndce Mffenbarn ruhend betrachtet warden, wenn die Veroffentlichung mit ezne Bnsug m Astlugoe adr anh einer oder mehreren anderen Veraf-fentlichungen dieser Kate- bezehtgonie in Verbindlung gebracht wird und die~e Verbindlung f~r Veroffentlichung, die -vor dem internationalen Anmeldeda- einen Fachmann naheliegend ist tum., aber nach dem beanspruchten Mrorit~tsdatum verdfient- Verdffentlichung, die Mitglied dersellben Patentfamilie itt Iicht warden ist IV. BESC14EINIGUNG______________ Datum des Abschlusses der internationalen Recherche 1Absendedatum des itrainlnRcecebrci

29..September 1988 14 0 C OT 1988 Internationale Recherchenbehondle Uttsehtit des t 1ebllachli,,en Beciensetjo. Europaisches Patentarmt gJi7 2\ DER PERPU TEN FOrmblatt PCT/ISA/21 0 (Blatrt 2) Ijanuer 1985) j~1 2 ANHANG ZUM INTERNATIONALEN RECHERCHENBERICHT OBER DIE INTERNATIONALE PATENTANMELDUNG NR. EP 8800650 SA 23217 In diesemn Anhang sind die Mitglieder der Patentfamilien deri m obengenannten internationalen Recherchenbericht angefrThrtcn Patentdokumente angegeben. Die Angaben fiber die Famiiienmitglieder entsprechen dem Stand der Datei des Europ~iischen Patentamnts am 06/10/88 Diese Angaben dienen nur zur Unterrichtung und erfolgen ohne Gewahr. Im Recherchenbericht Datum der Mitglied(er) der Datum der angeffihrtcs Patentdokument Verdffentlichung Patentfamiie T Verdffentlichung OE-A- 2158945 30-05-73 Keine EP-A- 0046088 17-02-82 JP-A- 57036115 26-02-82 AU-A- 7401081 18-02-82 US-A- 4431790 14-02-84 CA-A- 1169089 12-06-84 AU-B- 547172 10-10-85 Fur nahere Einzelheiten zu diesemn Anhang :siche Amtsblatt des Europaischen Patentamts, Nr.12/82