CA2087338A1 - Coating compounds based on polycondensation and polyaddition products containing hydroxyl groups, and the use of such compounds - Google Patents

Abstract

Coating agents based on hydroxyl-containing polycondensation and polyaddition products and their use Abstract of the Disclosure:
The present invention relates to coating agents based on hydroxyl-containing binders and isocyanate-containing crosslinking agents, in which coating agents I.) the binder comprises A1) 5 to 80% by weight of at least one polyester or one alkyd resin having an OH number from 0 to 200 mg of KOH/g and an acid number from 0 to 200 mg of KOH/g, A2) 95 to 20% by weight of at least one polyacrylate having an OH number from 30 to 250 mg of KOH/g and an acid number from 0 to 50 mg of KOH/g, the sum of the weight proportions of components (A1) and (A2) being in each case 100% by weight, and II.) the binder is obtainable from 1.) at least one polycondensation resin whose acid component comprises 5 to 100 mol% of cycloaliphatic polycarboxylic acids and/or esteriflable derivatives thereof, 2.) at least one polyacrylate, at least some of which has been prepared in the presence of the polycondensation resin obtained in the first process step and 3.) if desired, at least one further polyaddition and/or one further polycondensation resin.

Description

2~ 33~

~7.07.1990 BASF Lacke + Farben Aktiengesel.lschaPt, Munster S Coatinq aqents based on hydroxyl-containi~
polycondensation and polyaddition product~ and their use The present invention relate~ to coating agents based on hydroxyl-con~aining polycondensation and polyaddition products, compri~ing A) a hydro~yl-containing componen~ (~) a~ binder, B) at least one polyisocyanate as cro~slinking agent C) one or more organic solvent~, D) if dssired, conventional auxiliarie~ and additlves, in which component~ (~) and ~B) are present in such amounts that the ratio o~ ~he number oP free OH group~ of component (A) to the number of i~ocyanate groups of component (B) i8 in the range from 1 : 3 to 3 : 1.
The invention Purthermore relate~ to proces~as for the preparation of the~e coating agents and to the use oP the coating agents in automotive refinishlngr in particular as clearcoat.
Coating agents ba~ed on a combination of a polycondensation resin and a polyaddition resin are known.
Thus~ in German Patent 2 r 806,497~ clearcoat~ Por multi-layer coating~ are de~cribed compri~ing a mixture of a hydroxyl-containing polye~ter and a hydroxyl-containing 3(~
-- 2 ~

acrylata re~in a~ the blnder. The clearcoa~ contain an amino resin a~ the cro~slinking agent. The use of aliphatic and/or cycloaliphatic polycarboxylic acids and aliphatic and/or cycloaliphatic polyols in the S preparation of -the polyester~ give3 clearcoat~ which, compared with clearcoats ba~ed on binder~ containing aromatic bullding blocks, have impro~ed weathering re~istance. However, the~e clearcoats described in German Patent 2,806,497 ar.e in need of improvement with respect to drying capacity and proce~ibility.
Furthermore, many product information ~heets from Eastman Kodak on cyclohexanedicarboxylic acid have disclosed that the u~e of cyclohexanedicarboxylic acid as the acld component in polyester~ which are used a~
binders in paints, re~ult~ in good stability of glo3~ and crack resistance of the reR~lting coatings. ~owever, coa~lng agents ba~ed on polyesters containing cyclo-hexanedicarboxylic acid have the di~advantage that while having good d~ying capacity, they neverthale~s have at the same tLme only a very limited pot life, i.e.
proce~Ring time.
Furthermore, the product information shee~. from Bayer AG on De~mophen A 365 has di~clo~ed air-drying automotlve repa~r coating~ which contain a hydroxyl-containing binder ~Desmophen A 365~ as the bLnder andpolyLsocyanate~, such a~, ~or example, ~esmodur N 3390 and ~e~modur N 75, a~ the cro~linking ag0n~. The 2 ~ 3 ~

coatings obtained are di~tinguished by a good stability of glos~ and by high light stability and chalking resistance. However, their di~advantage is the e~tremely short pot life of the coating composi~ions.
Furthermore, German Of~enlegungsschrift 3r8061641 has disclosed coating compo~itions which contain a mixture of a csrboxyl-con~aining polyester and a carboxyl-containing acrylate resin ai the ~$nder. Epoxy resins are used in tha~e coating composition~ a~ the crosslinking agant.
Finally, it is known to Lmpro~a the compatibility of the individual components of binder mixtures by carrying out the synthe~is of one component in the pxe~ence of the other component.
Accordingly, the present invention is ~ased on the ob~ect of providing coatlng compo~itions based on polycondensate resln~ and polyaddition resins which show rapid drying and ~imultaneously have a long pot life, ie.
can be processed ln the ready-to-use state o~er a long period of time. Furthermore, ît i~ desired that the coating compositions are cured at room temperature or slightly elevated temperature, thu~ enabling them to be used in automotive re~inishing. Furthermore, they should at least fulfil the demands usually made on a clearcoat and pos~ibly have improved mechanical propextie~ compared with conventional clearcoats. Thus, the coating com~osi-tlons should exhiblt, ~or example, good ~tability of ~ !3 gloss, crack re~istance, filling pow~r and good flow ~3roperties.
Surprisirlgiy, this ob~ect is achieved by coating agents based on hydroxyl-containing polycondensation and polyaddition products, compri~ing A) a hydroxyl-containing component (A) as binder, B) at least one polyisocyanate as c:rosslinking agant, D ~ if desired, customary auxiliaries and additive~, in w ~ h componsnts (A) and (~) are present in such amounts ~ t the ratio of the number of free OH groups of component ~A) to the number of isocyanate group~ of component (B ~ ~ in the range from 1 : 3 to 3 : 1.
- In the ~ ating agents, I.) component ~A ~comprises Al) 5 to 80~ ~ weight of at least one polyester and~or one a~ ~ d resin (A1) having an O~ number from 0 to 200 ~y of ~OHJg and an acLd num~er from 0 to 200 mg ~ KOEI~g and A2) 9S to ~0% by w~ ght of at lea~t one polyacryl8te ~2) hav ~ an OH number from 30 ~o 2S0 mg of KOH~g and an\acid number from 0 to 50 mg of KOHtg, the 8um 0~ the weight proport.ion~ o~ co~l~onents ~A:l) and 2S [A2) b~lng in each ca8e 100~ by weight an~
II.) componen~ (A) f.s obtainable Prom 2~ 3~

C) one or more organic ~olvents, D) if desired, customary auxiliarie~ and additives, in which components (A) and (B) are present in such amount~ that the ratio of khe number of free OH groups of component (A~ to the number of .isocyanate group~ of component (B) is in the range from 1 : 3 to 3 : 1.
In the coating agents, I.) component (A) comprisss Al) 5 to 80% by weight of at least one polyester and/or one alkyd resin (A1) having an OH number from 0 to 200 mg of KOH/g, an acid number from 0 to 200 mg of R~H/g an~ a number average molecular weight of between 500 and 10,000, preferably between 1,000 and 5,000, A2) 95 to 20% by weight of at least one polyacrylat~
(A2) having an OH number from 30 to 250 mg of KOH/g, an acid number from 0 t.o 50 my of KOH/g and a number average molecular weight of between REPLACEMENT SHEET

2~733~

1,000 and 10,000, preferably between 1,500 and 6,000, the sum of the weight proportions of components (Al~ and (A2) being in each case 100~ by weight and II.) component ~A) is obtainable from 1.) at least one polyester and/or one alkyd resin (Al), which i9 obtainable by reaction of 2) p~lyc~lrbvxylic acids and/or esterifiable derivatives thereof and, if d2sired, monocarboxylic acids, 5 to 100 mol% of this carboxylic acid component being cycloaliphatic polycarboxylic acids and/or esterifiable deri~ative~ ther~of, b) polyols, if desired together with monools/
c) if desired, further modifying components, and d) if desired, a component capable of reacting with the reaction product from a), b) and, if desired, c), 2.) at least one polyacrylate (A2), at least some of which has been prepared in the presenc~ of coll~p~jne~t (~l) obtained in the first process step usi~ ~,~ 5 to 30~ by weight, based on the total weight o~ the monomers employed, of at least one vinyl ester o ~aturated aliphatic REPLACE~ENT SHEEq' 3 ~
- G -monocarboxylic acid~ having 9 to 11 carbon atoms which are branched a-t the ~ carbon atom, and 3.) if desired, at leas-t one further polyaddition andtor one further polycondensation re~in.
The invention furthermore relates to processes for the preparation of these coating agents and to their use in automotive refinishing, in particular as clearcoat.
In what follows, first the individual components of the coating agents accordin~ to the invention are no~
illustrated in more detail.
The hydroxyl-containing component (A) of the coating agents according to the invention used as binder comprises A1) to 80% by weight, prefexably 40 to 60% by weight, of at least one polyester and/or one alkyd resin ~Al) and A2) 95 to ~0% by weight, preferably 60 to 40% ~y weight, of at least one polyacrylate (A2), the sum of the weight proportion~ of components ~A1) and ~A2) beinq in each case 100% by weight. The polyester~ or alkyd resins used a~ component ~A1) have OH numbers from 0 to 200 mg of KOH/g, preferably 30 to 150 mg of KOHJg and acid numbers from 0 to 200 mg of KOH/g, preferably S to S0 mg of KOH/g. The number-av2rage molecular weights of th~se polyesters or alkyd resins are between 500 and 2S 10,000, preferably between 1000 and 5000, in each case REPI~CEMENT SHEET

2~$733~
,, mea~ured by GPC against a poly6tyrene standard. The polyesters or alkyd resin~ can, if desired, contaln tertiary amino groups.
These polyesters or alkyd resin~ tA1~ are~
obtainable by reaction of a) polycarboxylic acid~ or eqterifiable derivative~s ~:thereof, if desired together with monocarboxylic acids, : ~: : ~ :

:: :

;

, . : ~ : ~ :

:
REPLACEMEN~ ~HEE~
, ~ :
;.~ :
; :
:: :
,~: : ;
~:

~ ~' , ' ,.

. I .

~7~1 2 ~ (~ sl 3 ;~3 ~
-- ~F
The hydroxyl-containing component (A) of the Coatin agents according to the invention used as bin~ r comprlses Al~ 5 to 80~ by weight~ prefarably 40 to 60~ by ~ ight, of at least one polye~tsr andtor one a ~ ~sic]
re~in ~A1) and A2) 95 to 20% by weight, preferably 60 to ~% by welght, of at lea~t one polyacrylate (A2), /
the sum o~ the weight proportions of ~mponents (A1) and (A2) being in each case 100~ by weL~t. The polyester~ or alkyd resin~ used as component ~ ) have OH number~ from 0 to 200 mg of KOH/g, prefer ~ly 30 to 150 mg of RO~/g and acid numbers from 0 to/200 mg o ~OHig, preferably S to 50 mg of KOH/g. ~he ~ er-average molecular weights of these polyesters or/alkyd resLns are usually betwsen 500 and 10,000, pref~ ably between 1000 and 5000, in each case measured by ~ ~C against a polystyrene ~tsndard. The polyester~ or ~lkyd resins can, if desired, contain tertiary ami76 groups.
Thf~e polyesters or alkyd resin~ (Al~ are obtalna~e by reacti.on o~
a) ~ ycarboxylic acids or e~terifiable derivatives / thereof, if desired together with monocarboxylic ~ac.ids., ~5 b) polyol~, 1 desired tos~ekher with monoola, c) i~ desired, further modi~ying components and ~3~3 d) if de~i.red, a component capable of reacting with the reaction product from a)~ b) and, if desired, c).
Carboxylic acid componen~ a) used for preparing the polyesters or alkyd re~in~ (Al) comprise~ S to 100 mol%, prefer~bly 30 to 100 mol%, and particularly preferably 50 to 100 mol~, in each ca~e relative to the total amoun~ of component a), of cycloaliphatic polycarboxylic acid~ and/or es~exifiable derivativea thereof.
ExampleR of suitabl~ cycloaliphatic polycarboxylic aclds are tetrahydroph~halic acid, hexahydrophthalic acid~
1,2-cyclohexanedicarboxylic acid, 1,3-cyclohaxane-dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic acid/ Pndomethylanetetrahydro phthalic acid, tricyclodecanedicarboxylic acidl endoethylenehexahydrophthalic acid, camphoric acid, cyclohexanetetracarboxylic acid and cyclobutanetetra-carbo~ylic acid. Preference i~ given ~o the use of 1,4 cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydrophthalLc acid and alkyl-sub~t.~tuted deriva~ives thereof and particular pre~erence to the u~e of 1,4-cyclohexanedicarboxylic acid.
The cycloaliphatic polycar~oxylic acids can be uRed not only in their ci~ but al~o in their trans form and a8 a mixture o~ both form~.
Example~ of suitable polycarbo~ylic acids, which, i~ deslred, c~n be u~ed together with the cycloaliphatic J3 ~ ~

polycarboxylic acid~, are aromatic and aliphatic polycarboxylic acids, such a~, for example, phthalic acid, i~ophthalic acid, terephthalic acid, halogeno-ph-thalic acids, such a~ tetrachloro- or tetrabromo-phthalic acid, adipic acid, glutaric acid, a~elaic acid, ~ebacic acid, fumaric acid, maleic acid, trimellitic acid, pyromellitic acid, and the like.
Esterifiable derivatives of the abovementioned polycarboxylic acid~, ~uch a~, for example, mono~ or polyesters thereof with aliphatic alcohols having 1 to 4 C atoms or hydroxyalcohol~ havlng 1 to 4 C atoms are a1YO
suitable. Moreover, the anhydride~ o the abovementioned acid~ can al~o be used, if ~hey exi~t.
If de~ixed, monocarboxylic acids, ~uch a~, for example, benzoic acid, tert.-bu~ylben~oic acid, lauric acid, isononanoic acid and fatty acid~ of na~urally occurrin~ oi.l~, can al80 be used togather with the polycarboxylic acld~. ~he preferably u~ed monoc~rboxylic acid i9 isononanoic acicd.
Suitable alcohol componant8 b) for preparing the polye~tex or alkyd resin (A1) are polyhyclric alcohol~, ~uch a8 ethylene glycol, propanediol~, butanecliol~, hexanediol~, neopentylglycol, die~hylene glycol, cyclohexanediol,cyclohexanedimethanol,trimethylperltane-2.5 d.lo:L, ethylbutylpropanediol, ditrime~hylolpropane, tri-methylolethane, trimethylolpropane r glyeerol, penta-erythritol, dipentaerythritol, tri~(hydroxyethyl) g isocyanate, polyethylene ~lycol, polypropylene glycol, if desired together with monohydric alcohols, such as, for example, butanol~ octanol, lauryl alcohol, ethoxyla~ed or propoxylated phenols.
Suitable components c) for preparing the polyester~ or alkyd resins (Al) are in particular compound~ having a group which is reactive toward the functional groups of the polyester, with the exception of the compounds mentioned a~ component d). Prefarably used modifying components c) are polyLsocyanates and/or diepoxy compound~, if desired al~o monoisocyanates and/or monoepoxy compounds.
Examples of suitable polyisocyanat0~ are toluylene dii~ocyanates, hexamethylene diisocyanate and isophorone diisocyanate. Diepoxy compound~ are under~tood to mean epo~y resins ha~ing on average about two epoxy group~ par molecule. Examples of suitable monoepoxy com-pounds are olefin oxide~, such a~ octylene oxide, butyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, p-butylphenol ~sic] glycidyl ether, cre~yl glycidyl ether, styrene oxide, glycidyl methacrylate, cyclohexanevinyl monoxide [8iC] ~ dipentene monoxide, ~-pinene oxlde and ~lycidyl e~ter~ of tertiary carboxylic acid~.
2S Suitable components d) for preparing the polyesker~ or alkyd resin~ ~Al) are compound~ which1 apart from a group reactive toward the functional groups 2~ 133~

of poly~ter (A1), additionally contain a tertiary amino group.
MonoLsocyana~es having at least one tertiary amino group are preferably used a~ component~ d) reactive wlth the reaction product from a), b) and, if d~sired, c). The~e can be prepared, for example, by reactln~
~uitable diisocyanates, such as isophorone dii~ocyanate, with amino alcohols having a tertiary amino group, ~uch a~, for example, hydroxyethylpyridine or dimethylamino-ethanol, or wlth polyamines having at least one tertiary and at least one ~econdary or primary amino group. The monoisocyanate~ are bonded to the binder system by reaction with free hydroxyl group~ of the polycondensa-tion and/or addition product with the formation of a urethane bond. The components d~ used can also be polyamines having at lea~t one ~er~iary and at lea~t one primary or ~econ~ary amino group. An example o~ these i8 dimethyla~inopropylmethylamine.
If the polye~ter or alkyd re~in (Al) contains ethylenlcally unsaturated double bonds, which are preferably introduced by using ethylenically unsaturated components a) and/Qr b), it i~ also possible to u~e mercapto compounds ha~Lng at lea~t one ~ertiary amino group a~ component d).
In thi~ ca~e, the component a) used .Ls, ~or example, maleic anhydride or unsaturated fatty acids; an example o~ an un3aturated alcohol suit~ble as component b) 11 2~733~
i~ 1,4-butenedlol. In thi~ ca~e, the mercapto groups of the aminothiol having a tertiary amino group undergo an addition reaction with the double bond~ introduced into the binder via component a) and/or b).
Apart from u~ing component d) (pol~ner-analogous reaction~, the tertiary amLno groups can also be introduced into the polyester or the alkyd resin (A1) by using amino-containlng polyols andJor polycarboxylic acids.
~ninocarboxylic acids having at leaRt one tertiary amino group can be u~ed, for example, toyether with the cycloaliphatLc and, $f deslr~d, further poly-carboxylic acids, as component a). Example~ of the~e are pyridine-2-carboxylic acid, pyridine-3-carbo~ylic acld, pyridine-4-carboxylic acid and pyridine-2,6-dicarboxylic acid. Furthermore, the reaction product of an amino alcohol with at least ona tertiary amino gxoup and a polycarboxylic anhydrLde and the reac~ion product of a polyamine having at lea~t one tertiary and at least one prlmary or ~econdary amino group and a polycarboxylic anhydride can be used.
Amino alcohol~ having at lea~t one tertlary ~mino group can be used a~ alcohol component b). Examples of these are 2-hydroxyethylpyridina, dimethylaminopxopanol, methyldLethanolamine, methyldipropanolamine and dlhydroxyethylanLline. Reactlon product~ o~ epo~y re~lnR
with carboxylic acid~ and/or amines can al~o be used as - 12 - ~3~13~3 alcohol component b~.
Thus, the reac tion product of low-molecular-weight epoxy resins with polycarboxylic ac.ids and/or polycarboxylic anhydrides and aminocarboxylic acids S having at least one tertiary amino group, which i8 then, if desired, esterified with the ac.id and the alcohol component and, if desired, modified with polyi~ocyanatee, can be used as alcohol component b). Low-molecular-weight epoxy reQlns are under~tood to mean epoxy resin~ having a molecular weight of le~s than about 2000. When epoxy resins are u6ed, typ~s which are low in chlorine ~hould be used, since othexwi~e strong di~coloration of the products can take place.
Poly2~ters (Al~ are prepared by the known method~
of esterification (cf. varioug standard works, ~uch a~, f or example:
1. Temple C. Patton, Alkyd Re~in Technology, Interscience Publishers John Wiley ~ Sons, New York~
London 19 6 2;
2 0 2 . Dr . Johannes Scheiber, Chemie und Technologie der kilnstlichan Harze ( Chemistry and Technology of Synthetic Rasine ), Wissenschaftliche Verlagsge~ellscha~t mb~l, Stut~gart, 19~3;
3. Han~ Wagner ~ Hane-Friedr.ich Sarx, Lackkunstharze (Synthetic Coat.ing Re~ins), 4th edition, Carl Hanser Vexlag, Munich, 1959;

2~3~

4. Ullmanns Encyklop~die dex technischen Chemie ~Ullmanns Encyclopedia oE Industrial Chemistry~, volume 14, pages ~0 to 106 (1963)).
This reaction i~ usually carried o~lt at temperattlre~ between 180 and 280~C, if desired in the pre~ence of a ~ultable esterification catalyst, ~uch as, for example, lithium octoate, dibutyl~in oxide, dibutyltin dilaurate, para-toluene~ulfonic acid, and the like, ~ ~ The~prep-ar~a~io~ ~f~he-po~yester~-or alky~ r~ n~
(A~ is usually carried out in the presence of 3mall amoun ~ of a suitahle sol~ent a~ entrainer. ~xample~ of entraine ~ which are used are aromatic hydrocarbon~, ~uch as, in ~ ticular, xylene and (cyclo)aliphatlc hydrocarbon~, ~ example cyclohexane.
The polya ~ late~ u~ed in the coat~ng agent~
according to the in ~ tion as component tA2) have OH
number~ from 30 to 250 ~ of ~OH/g, prsferably 50 to 180 mg of KOH/g and acid ~ er~ from O to 50 mg of XOH/g, preferably S to 20 mg of ~H/g. The number-a~erage molecular weiqhts of ~he polyaddlt ~ re~in~ are usually between 1000 and lO,OOO, preferably ~ etween 1500 and 6noo, mea~ured in each case by GPC agai~ ~ poly~tyrene ~tandard. IE de~ired, the~e polyaddition ~ ~in~ can contaln tertiary amino group~. \
It 19 e~ential to the invention that at ~ ~t some o~ the polyaddition re~in ~Al) h~s been prepared 2~ J3~

- 13,~-para~t-~u~n~ulo~-iG~ f-and-the-l~ke.
The preparation of the polye~ters or alkyd resins (Al) i~ usually carried out in the pre~ence of small amount~ o a suitable sol.vent as entrainerO Examples of entrainers which are used are aromatic hydrocarbon~, such as, in particular, xylene and (cyclo)aliphatic hydrocarbon~, for example cycloh0xane.
The polyacrylates used in the coating agen~s according to the invention as component (A2) have OH
numbers from 30 to 250 mg of KO~/g, preferably 50 to 180 mg of KOH/g and acid numbers ~rom 0 to 50 mg of KOH/g, preferably 5 to 20 mg of KOHlg. The number-average molecular weight~ of the polyaddition resins are between 1000 and 10,000, presrably between 1500 and 6000, mea3ured ln each aa~e by GPC agaln~t poly~tyrene ~tandard.
I~ deslxed~ these polyaddition ra~in~ can contain tertlary amino groups.

7.5 It i~ essential to the invention that at laa~t .some of the polyaddition resin (A~/) has been prepared in REPLACE~ENT SHEET

the presence of polycondensation resin ~A1).
Advantageously, at least 20% by weight and particularly advantageously ~0 to 80% by weight, of component IA2) are prepared in the presence of component (A1~. Any residual amount of component (A2) is then added to the binder solution or the coating agent. This already polymerized resin can have the same monomer composition as the polyaddition resin synthesized in the presence o the polycondensation resin. However, it is also possible to add a hydroxyl-containing polyaddition and/or polycondensation resin having a different mo~omer composition.~ ~ ~ !
s=~s~-t REPI~CEMEN~ SHEE~

2~7~`3(~

~ ~p~Y~ ~~~of--~po~r co~ndensation Advantageously, at least 20% by weight and par~ ~ larly advantageously 40 to 80% by weight, of comp ~ t (~) arP
prepared in the presence o componan ~ A1~.
Any residual amount ~ ponent ~A2) is then added to the binder solu ~ or the coatinq agent. This alxeady polymerL~e ~ in can have the same monomer composition a ~ polyaddition resin synthesized in the presence ~ the polycondensation resin. However, it i5 also ~ ~ible to add a hydroxyl-containing polyaddition -po~ ~nsa~n~e~in-~v-i~7~t~l0~ d ~U~-U ~
n~¦ Furthermore, it i9 possible to add a mixture of different polyaddition resins and/or polycondensation reEiins, one resin of which may have the same monomer compoeii~ion a~ the polyaddition re3in Lsynthesized in the presence of the polycondensation resin.
The hydroxyl groups are introduced into the polyaddition re~in (A2) by u~ing hydroxyl-containing monomers. 20 to 60~ by weight, preferably 25 to 45~ by weight, in each case relative to the total welght of the monomers used, of at lsast one hydroxyl-containing ethylenically unsaturated monomer ~component Pl) are u~ually used.
Suitable componants Pl) are hydroxyalkyl a~ter~ of ~5 ~ unsaturated carboxylic acids havin~ prLmar~ or ~scondary hydroxyl group~. If a high reactivlty of the acrylate copolymer i~ de~ired, it is po~sible to u~e ~733g exclusively hydroxyalkyl esters having primary hydroxyl groups; if a less reac-tive polyacrylate is desired, it is possible to use exclusively hydroxyalkyl esters having secondary hydroxyl groups. It is of course also possible to use mixtures of hydroxyalkyl es-ters having primary hydroxyl [sic] groups and hydroxyalkyl esters having secondary hydroxyl groups. Examples of suitable hydroxy~
alkyl esters of ~,B-unsatura-tecl carboxylic acids having primary hydroxyl grou~s are hydroxyethyl acrylate, hyclroxypropyl acrylate, hydroxybutyl acrylate, hydroxyamyl acrylate, hydroxyhexyl acrylate, hydroxyoctyl acrylate and the corresponding methacrylates. Examples of usable hydroxyalkyl es~ers having a secondary hydroxyl group are 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 1~ 3-hydroxybutyl acrylate and the corresponding methacrylates.
I~ is o course also possible to use in each case the corresponding esters of other ~,~-unsaturated carboxylic acids, such as, for example, of crotonic acid and isocrotonic acid.

3 ~3 - 15~

s At least some o the component Pl) can advantageou~ly be a reaction product of one mol of hydroxyethyl acrylate and/or hydroxyethyl methacrylate with on average two mol of ~-caprolactone. At least some of the component Pl) used can also be a reaction product of acrylia aci~ and/or REPLACEMENT SHEET

.

2 ~ S~ 3 methacrylic acid with the equivalent amount of a glycidyl ester of a carboxylic acid haYing a tertiary ~-carbon atom. Glycidyl esters of highly branched monocarboxylie acids are available under the trade name "Carcdura". ~he reaction of acrylic acid or methacrylic acid with the glycidyl ester of a carboxylic acid having a tertiary ~-carbon atom can take plaee before, durlng or after the polymerization reaction. Care should be taken that the acid number of the finished polyacrylate is in the range f~om 5 to 30 mg o~ KOH/g, preferably 8 to 25 mg of KO~/g.
To prepare the polyaddition resins ~A2), 5 to ~0~ by weight, preferably 5 to 20% by weight, in each case based on the total weight of the monomers usecl, of at least one vinyl ester of saturated, aliphatic mono-carboxylic acids having g to ll carbo~l atoms which arebranched at the A carbon atom (compoltent P2) are additionally used. The branched monocarboxylic acidR ean be obtained by reaetion of formic acid or earbon monoxide and water with olefins ln the pre~ence of a liquid, strongly aeidic catalyst; the olefins can be erac:king produets o paraffinie hydrocarbons, sueh as mineral oil fractions ~nd can eontain both branehed and ~traight-chain acyclic and/or cycloaliphatie olefins. q'he reaetion of ole~ins of thi~ type with ~ormic acid or with earbon monoxide and watex give~ a mixture of carboxylie aeid~ in REPL~CEMENT SHEET

~3'~3~

which the carboxyl group~ are predominantly on a quaternary carbon atom.
Examples of other olefinic starting materials are propylene trimer, propylene tetramer and diisobutylene. The vinyl esters can also be prepared in a manner known per se from the acids, for example by reacting the acids ~ith acetylene.
To prepare the polyaddition resins IA~)~ 10 to 80% by weight, preferably up to 60% by weightJ in each case based on the total weight of the monomers used, of at least one vinylaromatic compound (component p3) are usually additionally used. Component p3) preferably contains 8 to 9 carbon atoms per molecule. Ex~mples of suitable compound~ are styrene, vinyltoluenes, ~-methylstyrene, chlorostyrenes, o-, m- or p-methylstyrene, 2,5-dimethylstyrene, p-methoxystyrene, p~-tert.-butylstyrene, p-dimethylaminostyrene, p-acetamido-styrene and m-vinylphenol. Preference i~ given to the u~e o vinyltoluenes and in particular styrene.
To synthe~lze the hydroxyl-containing copolymer (A2), it i~ furthermore possible to u~e 0 to 35% by weight of other, ethylenically unsaturated, copolymerizable monomer~ (component p4). The selection of the monomer~ i~
not particu].arly critical. However, care must be taken that incorporation of these monomers does not lead to undesirable propertie~ o~ the copolymer. Thus, the REPLACEMENT S~IE.ET

2~ ~ d~

~o~
able monomers (component p4 ) . The --sel~t~on of the ,,",", -monom0r~ is not particularly c ~ l. However, care must ,,---' be taken that incor ~ on o~ these monomers doe~ not ., ~
S -~a~ e~-~-~ E~ tl~e--~op~ s, ~ lection of component p4 ) largely depends on the desired propertie~ of the curable compo~ition with re~pect to ela~tlcity, hardne~s, compatibility and polarity. Alkyl esters of olefinically unsaturated carboxylic acids are preferably used a3 compo~ent p4~.
Example~ of the~e are methyl ~meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylater i~opropyl tmeth)acrylate, isobutyl (m~th)acrylate, pentyl (meth)acrylate, i~oamyl (meth)acrylate, hexyl (meth)acrylate, cyclohe~yl ~meth)acrylate~ 2-ethylhexyl (meth)acrylate, octyl (meth~acrylate, 3,5,5-trimethyl-hexyl (meth)acrylate, decyl (meth)acrylate, dodecyl ~meth)acrylate, hexadecyl (me~h)acrylate, octadecyl (meth)acrylate, octadecenyl ~meth)acrylate and the corre~pondLng e~ter~ of maleic, crotonic, isocrotonic, vinylacetic and itaconic acid.
Furthermore, other ethylenically unsaturated compound~, ~uch as, for example, alkoxyethyl acrylates, aryloxyethyl acrylate~ and the corre~ponding methacrylates, such as, for ex~nple, butoxyethyl (meth)acrylate and phenoxyethyl (meth)ac~late are ~uitable as component p~). To improve compatibillty, it i8 al90 po~sible to incorporate 8m811 1 9 - 2 ~3 ~ r6~ 3 ~
amount~ of carboxyl-containing monomers by polymerization as component p43. Examples of suitable carboxyl-co~taining monomers are unsaturated carboxylic acids, such a~, for example, acrylic acid, methacrylic acid, it~conic acid, S crotonic acid and monoe~ter~ of maleic and fumaric ac.id and mixtures thereof. ~y using unsa~tuLa~ed compound~
having tertiary ~nino group~ a~ component p4 ), it i3 pOS-sible to incorporate tertiary amino group~ in copolymer (A2). Ex~nple~ of ~uitable monomers are NIN'-diethyl-1~ aminopropylmethacrylamide [sic], N,N~-diethylaminoethyl methacrylate [ 8iC ], 2-vinylpyridine, 4-vinylpyridine, vinylpyrroline/ vinylquinoline, vinyli~oquinoline, N,N~-dimethyl~ninoethyl E sic3 vinyl ether and 2-methyl-5-vinylpyridin~.
The polymerization o monomer components Pl) to p4) i~ preferably carried out with the exclusion of oxygen, for example by worXing in a nitrogen atmo~phere.
The reactor i~ equipped with ~uitable stirring, heating and cooling devices and with a reflux conden~er, in which volatile components, such a~, ~or example, ~tryene, are retained. The polymerization reaction i~ carried out at temperatures from 100 to 180C, preferably 130-170C, with the u~e of suitable polymerization initiator~ and, if desired, pol~nerization regulator~.
In particular, initiator~ containing ter~.-butyl group~, suah a~, ~or ax~nple, di-tert.-butyl peroxide, tert.-butylhydroperoxl.de,2,2-di-tert.-butylperoxybutane 2~ 3 ~,~

and 1,3-~bls(tert~-butylpero~yi~opropyl)benzene, and dibenzoyl peroxide are suitable for pr~paring the polyaddition resin~ (A2) in the presence of poly-condensation resins (hl). These initiator~ promote a grafting reaction of the acrylate copolymer onto the polyester. Apart from these abovementioned initiator~, the initiators u~ually used, ~uch as, for example, dicumyl peroxide, cumyl hydroperoxide, tert.-amyl perbenzoate, tert.-amyl 2-ethylperhexanoate, diacyl ln peroxides, such as, for example, diacetyl peroxide, peroxyketals, 2,2-di(tert.-amylperoxy)propane, ethyl 3,3-di(ter~.-amylperoxy)butyrate and thermolabile highly substituted ethane derivatives, for example based on silyl-subs~ituted ethane der~vatives and ba~ed on benzopinacole, are al80 ~lacuna~ for the preparation of the polyaddition resins tA2) which are not prepared in the pre~ence of the polycondensation resins (Al).
Furthermora, alipha~ic azo compounds, such as, or example, azoi~ovaleronitrile and azobis(cyclohexane-nitrlle), can also be u~ed.
The amount of initiator i~ in most cases 0.1 to8% by weight, relative to the amount of monomer to be processed, but it can, i desired, also be higher. The ini-tiator, which i~ dissolved in a portlon of the solvent used for the polymerization is gradually metered in during polymerization reactlon. Preferably, the initiator feed take~ about 0.5 to 2 houra longer than the monomer 3 ~ ~

- 2~
feed, so as to obtain a good effect al30 during the after-polymerization phase. If initiators havin~ only a small rate o decay are used under the reaction conditions present, it is also possible to initially introduce the initiator.
If desired, the polymerization can be carried out in the presence of a regulator. Suitable regulators are preferably mercapto compounds, mercapt;oethanol being used particularly preferably. Examples of other passible regulator~ are alkanethiols, such as, for example, t-dodecanethiol, octanethiol, thiophenol, octadecanethiol, butanethiol, 2-ethylhexyl thioglycolate, thiocarboxylic acids, such as, for example, thioacetic acid or thiolactic acid. These xegulators are used in an amount of up to 2%
by weight, based on the amount of monomer to be processed.
Preferably/ they are dissolved in one of the monomer feeds and added together with the monomer~. The amount of regulator added is preEerably constant with time.
The polymerization i~ prefera~ly carried out in a high-boiling, organic solvent which i9 inert toward the monomers u~ed. Example~ of suitable solvents are higher substituted aromatios, such as, for example, solvent naphtha, heavy benzene, various Solves~o~ types, variou~
Shellsol0 types and ~easol~ and higher-boiling aliphatic R~PLACEMENT SHEE'r ~3 ~3~

- 2~ -and cycloaliphatic hydrocarhons, such as, for example, various white spirits, mineral terpentine oil, tetralin and decalin and various esters, such as, for example, ethyl~lycol acetate, butylglycol acetate, ethyldiglycol acetate, and the like. Copolymer.ization of components P1) to p~) i5 preferably carried out a~ follows, such as also described in EP-A 349,818:
First, at least 60% by weight, preferably ~00%
by weight, of the total amount of component P2) to be used are initially introduced into the reactor together with a portion of the total amount of solvent to be used and heated to the particular reaction temperature. The remaining amount of solvent is, as already described, preferably added gradually together with the catalyst. Any residual amount of component P2) ~till present and the remaining monomers (components P1)l p3) and p4)) are metered in to the initially introduced component P2) over a monomer addition period which is the same for all components (it is in general 2-10 h, as i~ customary for acrylate copolymerizations) in the following manner:
i) The amount added per time unit of any component P2) still pre~ent ~ie. the residual amount of component P2) which wa~ not initially introduced) remains con~tant or decrea~es over ~EPL~CEMENT SHEET

the monomer addition period, the latter proces~
variant being preferred. In the case of a constant amount being added, component P2) is preferably metered in together with components P1) and p4).
ii) The amount of components Pl) and p~) added per time unit remains constant over the monomer additi.on period.
iii) The amount of component p3) added per time unit is varied over the monomer addition period ~uch that the total amount added of component p3) over the first third of the ~onomer addition period ..i~. 15 to 30 ~

REPLACEMENT SH~ET

'J~ ~ 3 ~

com~on~ ~J-a-nd p~). /
ii) The amount of components p~ and p4) ad~ ~per time unit remaLn~ constant within t ~ omer addition period- /
iii) The amount of compo ~ p3~ added per time unit i~
variad within ~ ~ onomer addition period ~uch that the total/ ~ unt added o component p3 ) within the fir~ ~ ird of the monomer addltion period is lS to ~ by weight, pre~erably 18 to 26% by weight, of the total amount of component p3). Within the second third of the monomer addltion period, a total of 25 to 40% by weight, preEerably 30 ~o 38% by weigh~, and within the last third of khe monomer addition period 35 to 60~ by weight, preferably 40 to 50% by weight, o~ the total amount of componen~ p3~ are metered in, the 5um of the amounts added in the first, second and third third being of course 100 by weight.
There are various pos~ibLlitie~ of varying tha amount of component p3) ~dded per time unit, the only critical ~actor being that the above-mentioned total amounts added in each third are observed. ~hus, for example, a ~tapwisa change in ~hs amount ef component p3 ~
added per time unlt i8 po~sible. Any deslred number of step2 in whiah the amount added is changed in each case c~n be ~elected. ~hu~, ~or example, i~ i8 possible to l.ncrease the amount added per tLme unit of component p3) 2~rJJ3~
- 24~-only at the beginning of the second and~or at the beginning o~ the third third. Within the third, the amount added per time unit remain~ then in each case constant. However, i~ i~ also po~ible ~o vary the amount of component added per time unit continuou~ly, in accordance with the limiting ca~e of an infinite number of steps.
It i9 a~umed that addLtion of the component~ in the manner indicated promotes copolymerization and reduces homopolymerlzation of the indlvidual component0.
Preferred coating compositions are obtained if component (Al) and/or component (A2) contain tertlary ~mi.no group~. Accordingly, it i8 preferred to u8e polycondensation re~lns (A1) hav}ng an amine num~er from 5 to 20 mg of KO~/g and/or polyaddition re~in~ (A2) having an amine number from S to 20 mg of KOH/g. The tertiary amino groups can be introduced into copolymer t~2) by the additional use of amino-containing monomer~.
However, the hydroxyl-containing polyesters or alkyd resins or copol~ners obtalned can al~o additionally be re~cted after the polymerization in a polymer-analogou~ reaction with compounds (V), which, apart from a tert~ary amlno group, addl~lonally contain a group reactive toward the functional group of the copolymer.
Compound~ ~V) which conta.ln on average 0.8 to l.S, preferably 1, Pree i~ocyanate groups per molecule are preferably u~ed.

~7~

The reaction of copolymers ~A~) with compounds (V) i8 carried out in a solvent which i inert ~o isocyanate, at temperatures from lO to 100Cr preferably 50 to 80C, i desired in the presence o~ organic tin compounds a5 catalysts, until an NC0 value of virtually zero ha~ been reached. The amount o~ ccmpound (V) i~ cho~en such that the re~ulting resin ha~ the above-mentloned amine n~mber.
Compound~ (v~ whi.ch are used for introducin~ a tertiary amino group into the binder are prepared by reacting dLisocyanates or polyL~ocyana~es with a la than stoichiometric amount of a tertiary ~mine. Suitable tertiary amines for thi~ reac~ion are those of the general formula NR~2R3, in which Rl i5 preferably an alkanol radical or another hydroxyl-containing radical and R2 or R3 can be alkyl or cycloalkyl radicals.
Preference is given to dialkylalXanolamines, ~uch as, for example, dimethylethanolamine, diethylethanolamine and higher homolog~ or isomer~ thereof.
Examples of suitable di- or polyisocyanates are:
Aromatic i~ocyanate0, such as, for example, 2,4-, 2,6-toluylene dii30cyanate and mixtures thereof, 4,4~-di-phenylmethane diiso¢yanate, m-phenylene dii~ocyanatel p-phenylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene dii.socyanate, 4,4-toluidine diisocyanate, xylylene diisocyanate and ~ub~tit~ted aromatLc systems, such as, for example, dianisidine dii~ocyanate3, 4,4-diphenyl "~ ~

ether diLsocyanates or chlorodiphenylene diisocyanates and higher functional aromatic i30cyanate~, such a3, for example, 1,3,5~triisocyanatobenzene, 4,4',4'~-triiso-cyanatotriphenylmethana, 2,4,6-trii~ocyantotoluene and 4,4'-diphenyldimethylm~thane 2,2~,5,5~ te~raisocyanate;
cycloaliphatic i~ocyanates, such as, o.r example, 1,3-cylcopen-tane [sic] diisocyanate, 1,4-cyclohexane diisocyanate, 1,2-cyclohexane [lacuna] and i~ophorone diisocyanate; aliphatic i~ocyanates, such a~, for example, trLmethylene dilsocyanat~, tetramethylene diisocyanate, pentamethylene dii~ocyanate, hexamethylene diisocyanate, trimethylhexamethylene 1,6-diisocyanate an~
tris(hexamethylene) trii~ocyanate.
Diisocyanates having i~osyanate group~ of different reactivity, such aa, for example, i~ophorone diisocyanate, are preferably u3ed.
ComponRnts (Al) and (A2) are preferably used in the coating agents in such amounts tha~ the binder component (A) ha6 an acid number of at mo~t 50 mg of ROH~g, preferably 5 to 20 mg of KOH/g, an OH number rom 30 to 200 mg of KOH/g, preferably 50 to }50 m~ of KOH/g and pxeferably an amine number from O to 20 mg of KOH/g, preerably 5 to 15 mg of ~OHtg.
The polyi30cyanates used a~ component (h) for crosslinklng the hydro~yl-aontaining binder~ nre the ~ame polyi~ocyanate~ whlch are also u~ed ~or preparing com-pound (V). Thu~, ~or ~uitable example~ see the description of compound (V). However, the polyisocyanate~
can furth~rmore also be linked to give prepolymers having a higher molecular weight. Of these, adducts of toluylene diisocyanate with trimethylolpropane, a biuret formed from 3 molecules of hexamethylene diisocyanate and trimers of hexamethylPne di:isocyanate and 3,5,5 trimethyl-1-1socyanato-3-isocyanatomethyl-cyclohexane may be mentioned.
The amount ~elected of the crosslinking agent u~ed is ~uch that the ratio of isocyanate groups of the cro~slinking agent to ~ydroxyl groups of componen~ (A) i~
in the range from 1:3 to 3:1.
Combinations with polyisocyanates or resins carrying isocyanate groups are rapidly crosslinked even at room temperat~re.
However, i~ is also possible to use the isocyanates described above, which have been reac~ed with conventional blocking agent~, such a~, for example, phenol~, alcohols, acetoacetic esters, ketoxime and ~-caprolactam. These combinations are s~able at room temperature and are in general only cured at temperatures above 100C. In special c~es, for example if acetoacetic esters are used ~or blocking, crosslinking can also taka place even below 100C.
~5 The coating agents according to the invention c:ontain one or more organ~c ~olvent~ a~ component ~C).
These solvents are usuall~ u~ed in amounts o~ 20 to 65 2 ~ ~ 3 ~.J ri -- 28 ~
by weight, preferably 30 to 55~ by weight, .in each ca~e r~lative to the total weight of ~he coating agent.
Examples of suitable solvents are the abovementioned compound~.
S The coating agen~ according to the invention can furthermcr~ contain cusromary auxiliaries and additives in the usual amountsl preferably 0.01 to 10% by weight, relative to the total weight of the coating agent (component D~. Example~ of ~uitable auxiliarie~ and additives are flow-improving agents, such as silicone oils, pla~ticizars, ~uch as pho~phoric es~ers and phthalic esters, viscosity-controlling additives, flatting ~gents, W ab~orb~r~, light ~tabllizers and, if desired, fillers.
The coating asent~ are prepared from components (A) to (D) in a known manner by mixing and, if nece~sary, disper~ing the individual componen~s (A) to (D).
~hese coating agsnt~ can be applied to a ~ub~trate in the form of a film by ~praying, flooding, dipping, roller application, knife application or bru~hing, after which the f~lm i~ cured to gi~e a firmly adherlng coating.
The curing of these coatin~ agents i~ u~ually : carried out at room temperature or slightly elevated temperature, advantageou~ly at temperature~ below 100C, pxe~er~bly at temperature~ below 80C. Hownver, the coatlng agent~ can al~o be cured under baking aonditlonR/

7 '~ 3 ~

ie. at temperatures of at least 100C.
Suitable ~ubstrates are in particular metal~ and wood, plastic, gla~, and the like.
Owing to the short curing times and low curing temperatures~ the coating agents according to the invention are preferably u~ed for automotive refinishing and the coating of large vehicles and truck super-structure3. However, depending on the cro~slînking agent used, they can also be used ~or automotive mas~-produc~ion coating.
Furthermore, they are in particular suitable as clearcoat.
The coating agants according to ths invantion are distinguished in particular by a short drying time in combination with long proeessibili~y (pot life).
Furthermorel the resul~ing coatings, in par~icular in the ca~e of clearcoat coating~, have good mechanical properties, such as, for example, good stability of gloss, good filling power and good flow properties.
Below, the Lnvention i~ illu~trated in more detail by way of exemplary embodimen~. All parts and percentages given are by weight, unless expressly stated otherwise.
1. Preparation of PolYe~ter3 l to 6 The raw materials li~ted in Table 1 are weighed into a 4 1 ~tainless ~teel boiler e~uipped with ~tLrrer, ~team-heaked column and w~ter separ~tor. Af-ter addition ~ ~ 6l~

of 4% (relative to the weighed amount of polye~ter raw materials) o xylene a~ entrainer, khe mixture is slowly heated (over a perlod of 5-7 hours) to 220C. The water formed is distilled off azeotropioally. After reaching an acid number of 12~1~ mg of XOH/g, the mixture L~ partly dis~olved with Shell~ol~A (a commercially availablo mixture of C3-C4-alkyl-substituted aromatics) to a non-volatile content of 70%.

- 31 _ 2~3~3~
Table 1: Compo~ition of polyes~ers l to 6 in mol Polyeqter resln 1 2 3 4 (C) S 6 (C) __~____~_______________________________~___________ __ PSA 0.77 l.0 1,4 ~CHDA 0.23 1.0 THPSA l . 0 HHPSA 1 . 0 IPS 1.() I'rimethylol- 1.08 1.08 1.08 1.18 1.2 1.07 propane Iosononanoic 0.62 0.62 0.62 0.70 0.70 O.S2 acid Characteristic value~:
Viscosity 7.g 3.9 ~.55 l9 6.6 ~.0 Acid number 14.7 14.3 13.8 12.3 10.3 12.0 OH number 107 107 106 130 140 lOO

(1,4-C~DA = 1,4-c~clohexanedicarboxylic acid, HHPSA = hexahydrophthalic anhydride, ~HPSA = tetra-hydroph~halic anhydride, IP5 = isophthalic acid, PSh -phthalic anhydride, C a comparison) OH number and acid number are given Ln mg of KOH/g; vi~cosity mea~ured on a plate/cone v~cometer at 23C, given in dPa~s; amount~ given in mol.

- 32 ~
2. Preparation of copolvmer ~olution~ 1 ~o 6 The preparation of the po.lyester-modified polyaddition resins i~ carried out in a 4 1 stainless skeel boiler equipped with ~tirrer, reflux conden~er and feed inlets. The initial feed~ are in each case the solutions of the polyester resin~ and variable amounts of a commercially available mixture of vinyl es~ers of saturated aliphatic monocarboxylic acids having predominan~ly 10 C atom~/ which are branched at the ~-C atom (commercial product VeoVa~ 10 from Shell~, and the mixture i~ heatsd to 165C.
Copolymer ~olution 1 The followLng are weighed into the boiler and mixed:
998.75 parts of polye~ter resin 5 118.32 parts of YeoVa~ 10 The followLng are weighed into the monomer feed and mi~ed:
236.64 parts of methyl methacrylate 236.64 parts of hydroxyethyl methacrylate 591.60 parts of styrene The following are weighed into the initiator feed and mixed 36.0 parts of di-tert.-butyl peroxide 124.2 parts of 5hellsol~
The monomer mixture i3 metered ln uni~ormly over a per.od of our hours and the inLtiator mixture over a ~ ' .
.

3 ~ ~

period of five hour~. During this addition, the temperature may drop to 160C. After the initiator addition is complete, afterpolymerization o~ the mixture i~ allowed to continua at lbO-165~C for ano~her two hours. The copolymer ~olutlon thu~ obtained has a solid~
content of 83.6% (15 minutes at 180C) and a ~i4co4ity, measured as a 55% ~trength ~olution in butyl acetate, of 3.9S dPa-s. The polymer ~olution is then partly di~solved with xylene to a ~olids content of 70~ and further dis~olved with bytyl [~ic] acetate to a 301id~ content of 60~. The vi~cosity of the 60~ ~trength ~olution i4 9.1 dPa. 8 . Acrylate copolymer 1 has an OH nu~ber of 86 mg of gO~/q. The mixture ha4 an acid number of 3.6 mg of ~O~/g and an OH number of 105 mg of KoHJg.
Co~lymer ~olution 2 The preparation of copolymer sol~tion 2 i8 carried out ~imllarly to tha preparation of copolymer solution 1. The amount~ of polye~ter precursor and monomer mlxture u~ed and the amount of initiator remain the sams relative to one another and are composed a~
~ollows:
The following are weiqhed into the boile:r and mixed;
600.00 parts of polyester resLn 1 fi3.00 part~ of VeoVa- 10 The following are weighed into the monomer feed and mixeds 1~6.00 part~ of m~thyl methacrylats 126.00 part~ of hydroxyethyl me~hacrylate 315.00 par~ of ~yrene The following are weighed into the initiator feed and m~xed:
12.6 part~ of di-tert.-bu~yl peroxide 85.60 part~ of Shell~ol~ A
Copolymer ~olution 2 obtained ana.logou~ly to the proces~ of copolymer solu~ion 1 ha~ a solids content after polymerization (15 minutes at 180C) of 83.4% and a viscosity (measured a~ a 5S~ strength solution in butyl acetate, of 3.2 dPa~ 8 . Analogou~ly to copolymer 1, copolymer 2 i9 fir~t dilu~ed with xylene to a ~olids conten~ of 70% and then with butyl acetate to a ~olid~
lS content of 60%. The original vl~co ity i~ 8.8 dPa-~. The acrylate copolymer has an OH number of 86 mg of KOH~g.
The mix~ure ha~ an acid number of 5.1 mg of ROH/g and an OH number of 95 mg of KOH/g.
Copolymer ~olution 3 The preparation of copolymer ~olution 3 ia carried out ~imilarly to ~he preparation of copo:L~mer ~olution 1. I'he amount~ of polye~ter precur~or and monomer mixture u~ed and the amount of initiator remain the ~ame relative to one another and h~ve the following compo~Ltion~

. .

:

2 $ ~

The follow.ing are weigh2d in~o the boiler and mixed:
~00.00 parts of polye~ter re3in 2 63.00 parts of VeoVa lO
The ~ollowing are weighed into ~he monomer feed and mixed:
126.00 parts of methyl methacrylate 126.00 part~ of hydroxyethyl methacrylate 315.00 parts of styrene The ollowing are weighed into the initiator feed and mixed:
12.6 part~ of di-tert.-butyl peroxide 85.60 part~ of Shellsol~ A
Copolymer ~olution 3 obtained analogously to the process of copolymer solution 1 has a solids content after polymerization (15 minutes at l~OaC~ of 82.1% and a vl~cosity ~measured a~ a 55% trength solution in butyl acetate, of 5.1 dPa.s. ~nalogously to copolymer 1, copolymer 3 is first diluted with xylene to a ~olid~
content of 70~ and then with butyl acetate to a solids content of 60%. The original vi~cosity i~ 18.5 dPa.~. The acrylate copolymer 3 has an OH number of 86 m0 of KOH~g.
The mixtuxe ha~ an acld number of 5.~3 mg of KOH/g and an OH number of 95 mg of KOH/g.
~o~ym~ y~io~_~
The preparation of copol~mer ~olution 4 is carried out sLm1larly to the prepar~tion o~ copol~mer 2 ~ ~ r~

~olution 1. The amount~ of polye~ter precur~or and monomer mixture u~ed and the amOUJlt o initiator remain the same relati~e to one ~nother and have the following compo~itlon:
The following are weighed in~o the boiler and mixeds 600.00 parts of polyester resin 3 6~.00 parts of VeoVaC .10 The followlng are weighed into the monomer feed and mixed:
125.00 part3 of methyl methacrylate 126.00 part~ of hydroxyethyl methacrylate 315.00 part~ of styrene The following are weighed into the initiator feed and mixed:
12.6 parts of di-tert.-butyl peroxide 85.60 parts of Shellsol- A
Copolymer ~olution 4 obtained analogou~ly ko tha proce~s of copolymer solution 1 ha~ a solid3 content af~er polymerization (15 mlnutes at 180C) of 83.5~ and a vi~c08ity (measured as a 55$ ~trength solutLon in butyl acetate, of 2~3 dPa.s. Analo~ou~ly to copolymer 1, copolymer 4 i~ irst diluted with xylene to a solids content of 70~ and then wlth butyl acetate to a solld~
con~ent o~ 60%. The original viscosLty i8 6.05 dPa.~. The acrylate copol~mer 4 has an OH n~mber of 86 mg of KOH/g.
The mlxture ha~ an OH number o~ 95 mg o~ KOH/g and an , :

3 ~

acld number oE 6.50 mg of KOH~g.
Co~olymer ~olution 5 Icomparison~
The preparation of copolymer ~olution 5 i9 carried out Rimilarly to the prepara~ion of copolymer ~olution 1. The amounts of polyester precurRor and monomer mixture u~ed and the amount of initiator remain the s~me rel.ative to one another and have the followLng compo~ition:
The following are weighed into the boiler and 10 mixeds 600.00 part~ of polyester resin 4 63.00 parts of VeoVa~ 10 The following are weighed into tha monomer feed and mixed.
126.00 part~ of me~hyl methacrylate 126.00 parts of hydroxyethyl methacrylate 315.00 part~ of styrsne The following are weighed into the initiator feed and mixeds 12.6 parts of di-tart.-butyl peroxide 85.60 parts of Shellsol~ A
Copolymer ~olution 5 obtained analogou~ly to ~he process of copolymer ~olution 1 ha~ a solid~ content after polymerization (15 minute3 at 180~C) o 81.5%
(where the ~oli.ds content i~ measured, it i3 necessary to add xylene) and a ~iscosLty (mea~ured a~ a 55~ strength solution in butyl ~cetate, o~ 4.6 dPa~. An~logously to ~$ ~3$$
- 3~ -copolymer 1, copolymer 5 is first dilu~ed with xylene to a solids content of 70% and then with butyl acatate to a solids content of 60%. q~he original viscosity i~
14.0 dPa-s. The acrylate copolymer 5 has an OH number of 86 mg of KOH/g. The mixture ha~ an acid number of 5.1 mg of KOH/g and an OH number of 105 mCJ of KOH/g.
Copol~mer solution_6 ~comparlson!
The preparation of copolymer ~olution 6 is carried out similarly to the preparation of copolymer olution 1. The amount3 of polyester precur~or and monomer mixt~re u~ed ancl the amount of initlator xemain the same relative to one another and have the following composition:
The followinq are weighed ~n~o the boiler and 15 mixed:
600.00 parts of polye~ter re~in 6 63.00 parts of VeoVa- 10 The following are we~ghed into the monomer feed and mixeds 126.00 par~s of methyl methacrylate 126.00 parts of hydroxyethyl methacrylate 315.00 part~ o~ ~tyrens ~he ~ollowing are weighed into the initiator feecl and mixed~ .
12.6 parts of cli-tert.-butyl perox~de ~5.60 parts of ~hellsol~ A

13 f'i ~

Copolymer solution 6 obtained analogously to the process of copolymer solution 1 ha~ a solids content after polymerization ~15 minutes at 180C) of 81.5%
(where the solids content is measured, it is nece~ary to 5 add xylene) and a visco~ity ~measured as a 55% strength solution ln butyl acetate, o~ 3.5 dPa~s. Analogou~ly to copolymer 1, copolymer 6 is first diluted with xylene to a solids content o~ 70% and then with butyl acetate to a sol~ds content of 60~. The original viscosity is 9.O dPa.~. The acrylate copolymer 6 ha~ an OH number of 86 my of ~OH/g. The mixture has an acid number of 5.6 mg of KO~/g and an OH number of 92 mg of KOH/g.
3. Preparation of a paint reduction 1 Paint reduction 1 iB prepared from the following components:
15 parts of xylene 13 part~ of ~olvent naphtha 10 part~ of a commercially available hydrocarbon mixture having a boiling rang0 of 135-185C and an aromatic3 content of about 16.5%
SO parts of butyl acetate 5 parts of l-methoxypropyl 2 acetate 3 part~ of butylglycol aca~ate 2 parts of 3-methoxybutyl acetate 2 parts of a commercially available mixture of monoayclic terpenes having a boiling range o~
162-1~2C

~7~
~o 4. Preparatlon of a curinq aqenk solution 1 Curing aqent solution 1 is prepared from the following components:
50.6 parts of ~rimerized hexamethylene dilsocyanate, 90% strsngth solution in a 1:1 ~ixture o butyl acetate and solvent naphkha 10.8 part~ of ~olvent naphtha 7.5 parts of xylene 1.5 parts of butyl acetate 1014.0 part~ of 1-methoxypropyl 2-acetate 11.0 parts of butylglycol acetate 4.0 part~ of a 1% ~trength solution of dibutyltin dilaurate in a 1:1 mixture of ~ylsne and butyl acetate 1~0.6 part o a commercially available silicone oil Examples l to 5 and ComParative Examples 1 to 3 Clearcoat solutions 1 to R are prepared from the components li~ted in Table 2 by mixing.

.

213 ~3 r~l 3 3 ~
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E~ ~ m ~ u u u u u u u u 2 ~ 3 Copolymar solution 7 is Desmophen- A 365 from Bayer; copolymer ~olution ~ is a commercially available Cardura~ ~ 10 modified OH acrylate, which is used in au~omotive repair coatings S (commercial product Macrynal'~ SM 513 from Hoechst).
The clearcoat solu~ion~ are pre-diluted with pain~ red~ction 1 and then brought to a vi~cosity, measured in the DIN 4 cup at 23C, of 18 second with paint reduction 1. The paLnt solution~ are ~hen mixed wlth curing agent solution 1 in a mi.xing ratio of 2:1. In order to determine the pendulum hardnes6, coated gla~s panel~ are prepared from the paint~ by ca~ting, and the films are baked at 60C ~or 30 minute~ or left at room temperature for 24 hours. At a layer thickness of 20 ~m (dry), the pendulum hardnes~ of the film i9 then determined. For the other test procedure~, the paint i~
applied to phospated and coated steel sheets. To this end, the pho~phated steel ~heets are coated wlth a commercially available 2~component polyurethane ~iller (OH components = polyestRr-modifled hydroxyl-containing acrylate having an OH number of 90-110 mg of ROH/g;
isocyanate component = hexamethylene diisocyanate.
trimerized via a biuret s~ructure), dried overnight and ~hen cva~eA wi~h a commercially available, conventional.
metalllc base coat ~dried by physical means, based on polyester re~in, melamine ra~in, cellulose acetobutyrate, :
'' ' ' , . .

~7~3~

aluminum fl3kes). After a flash-off time ef 30 minutes, tha clearcoat is applied. The panels are immediately sub~ected to th~ tests described. The results are summarized in Tables 3 and 4.

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~ 4~ -Explanations for Table 3 and Table 4:
1) Pendulum hardness according to Konig in s 2) Dust-dry: about 15 minutas after spraying on the paint, a small sample of seasand (3-4 g~ is spread on a cornex of the panel. The panel i9 then hit from a height of 30 cm with ~he edge agains~ the ground (free fall). It is du~t-dry if no sand adhPre~. The test is repeated after 15 minutes each time, and shortly before it becomes du~t-dry the repetition interval is shortened to 5 minutes.

3) Touch-dry About 20 minutes after having becom dust-dry, the painted panel i~ covered with a sheet o paper about 3 cm2 in si~e. A small rigid plastic sheet is placed on this paper, and then a 100 g weight is placed on top. After exactly 1 minute, a~ in the test for dust drynes~, it is te~ted whether the paper still adheres. The tLme interval i8 a~ in the te~t for dust dryne~.

20 4 ) Drying recorder:
The te~t L~ carried out by the ~ollowing proceclure.
It wa~ sLlghtly modi~ied compared with th~ o~ the drying recorder model 504 from Erichsen.

- ~7 -Refore ~he steel ~heets are coated with the base coat, glass ~tripes, 25 mm wide and 30 cm long, are qlued onto the particular test panel longi~udinally.
The test p~nel~ along with the gla~s ~tripe3 are S then coated with ~he base coat and, a-fter a flash-off tLme of 30 minute~, with the clearcoat. The qlass stripe~ are removed and clamped into a special te~t device (drying recorder). By means o~ the drying recordar, a needle haviny a diameter of 1 mm is then moved acros~ the coating for a period of 6 hours. This lead~ to the formatLon of three scratch traces, called phases, caused by the d~ying of the coating. In the first pha~e, the needle penetrates to the glass, and the paint s~111 coale~ce~. In the ~econd pha3e~ a clear scratch trace can be observed, and the paint no longer coale~ces. In tha third pha~e, the needle penetrate~
into the coa~ing ~urface only very slightly and only leava~ a trace which i~ baxely vi~ible. The middle of transition between two clearly definable phase~
is called phase transition.

The te~ts were carried out in each case at an ambient temperature o~ 26~28~,

Claims (16)

26.05.1992 New Patent claims

1. A coating agent based on hydroxyl-containing polycondensation and polyaddition products, comprising A) a hydroxyl-containing component (A) as binder, B) at least one polyisocyanate as crosslinking agent, C) one or more organic solvents, D) if desired, conventional auxiliaries and additives, in which the components (A) and (B) are present in such amounts that the ratio of the number of free OH groups of component (A) to the number of isocyanate groups of component (B) is in the range from 1 : 3 to 3 : 1, in which I.) component (A) comprises A1) 5 to 80% by weight of at least one polyester and/or one alkyd resin (A1) having an OH number from 0 to 200 mg of KOH/g, an acid number from 0 to 200 mg of KOH/g and a number average molecular weight of between 500 and 10,000, preferably between 1,000 and 5,000, A2) 95 to 20% by weight of at least one polyacrylate (A2) having an OH number from 30 to 250 mg of KOH/g, an acid number from 0 to 50 mg of KOH/g and a number average molecular weight of between 1,000 and 10,000, preferably between 1,500 and 6,000, the sum of the weight proportions of components (A1) and (A2) being in each case 100% by weight and REPLACEMENT SHEET

26.05.1992 II.) component (A) is obtainable from 1.) at least one polyester and/or one alkyd resin (A1), which is obtainable by reaction of a) polycarboxylic acids and/or esterifiable derivatives thereof and, if desired, monocarboxylic acids, 5 to 100 mol% of this carboxylic acid component being cycloaliphatic polycarboxylic acids and/or esterifiable derivatives thereof, b) polyols, if desired together with monools, c) if desired, further modifying components, and d) if desired, a component capable of reacting with the reaction product from a), b) and, if desired, c), 2.) at least one polyacrylate (A2), at least some of which has been prepared in the presence of component (A1) using from 5 to 30% by weight, based on the total weight of the monomers employed, of at least one vinyl ester of saturated aliphatic monocarboxylic acids having 9 to 11 carbon atoms which are branched at the A
carbon atom, and 3.) if desired, at least one further polyaddition and/or one further polycondensation resin.

2. A coating agent as claimed in claim 1, wherein component (A) comprises 26.05.1992 A1) 40 to 60% by weight of at least one polyester and/or one alkyd resin (A1) and A2) 60 to 40% by weight of at least one polyacrylate (A2).

3. A coating agent as claimed in claim 1 or 2, wherein 30 to 100 mol% of cycloaliphatic polycarboxylic acids or esterifiable derivatives thereof have been used as component a) for preparing the polyester or alkyd resin (A1).

4. A coating agent as claimed in one of claims 1 to 3, wherein cyclohexane dicarboxylic acid and/or tetra-hydrophthalic acid and/or hexahydrophthalic acid and/or alkyl-substituted derivatives thereof have been used as cycloaliphatic polycarboxylic acid (component a)) for preparing component (A1).

5. A coating agent as claimed in one of claims 1 to 4, wherein cyclohexane-1,4-dicarboxylic acid and isononanoic acid have been used as cycloaliphatic polycarboxylic acid (component a)) for preparing component (A1)

6. A coating agent as claimed in one of claims 1 to 5, wherein component (A2) has been prepared using from 5 to 20% by weight, based on the total weight of the monomers employed, of at least one vinyl ester of saturated aliphatic monocarboxylic acids having 9 to 11 carbon atoms which are branched at the .alpha. carbon atom.

REPLACEMENT SHEET

26.05.1992

7. A coating agent as claimed in one of claims 1 to 6, wherein polyesters and/or alkyd resins having an OH
number from 30 to 150 mg of KOH/g and an acid number from 5 to 50 mg of KOH/g have been used as component (A1) and/or polyacrylates having an OH number from 50 to 180 mg of KOH/g and an acid number from 5 to 20 mg of KOH/g have been used as component (A2).

8. A coating agent as claimed in one of claims 1 to 7, wherein 40 to 80% by weight of component (A2) have been prepared in the presence of polyester (A1).

9. A coating agent as claimed in one of claims 1 to 8, wherein the polyester and/or alkyd resin (Al) and/or polyaddition resin (A2) contain tertiary amino groups.

10. A coating agent as claimed in one of claims 1 to 9, wherein the polyester and/or alkyd resin (A1) have an amine number from 5 to 20 mg of KOH/g and/or polyacrylate (A2) has an amine number from 5 to 20 mg of KOH/g.

11. A coating agent as claimed in one of claims 1 to 10, wherein binder (A) has an OH number from 30 to 200 mg of KOH/g and an acid number from 5 to 50 mg of KOH/g.

12. A coating agent as claimed in one of claims 1 to 11, wherein binder (A) has an OH number from 50 to 150 mg of KOH/g and an acid number from 5 to 20 mg of KOH/g.

13. A coating agent as claimed in one of claims 1 to 12, wherein component (A) has an OH number from 80 to 120 mg of KOH/g and an acid number from 5 to 20 mg of REPLACEMENT SHEET

26.05.1992 KOH/g, component (A1) having an acid number from 0 to 20 mg of KOH/g and component (A2) an acid number from 0 to 20 mg of KOH/g.

14. A process for the preparation of the coating agent as claimed in one of claims 1 to 13, which comprises mixing and, if necessary, dispersing A) a hydroxyl-containing component (A) as binder, B) at least one polyisocyanate as crosslinking agent, C) one or more organic solvents, D) if desired, conventional auxiliaries and additives, in which components (A) and (B) are used in such amounts that the ratio of the number of free OH groups of component (A) to the number of isocyanate groups of component (B) is in the range from 1 : 3 to 3 : 1, in which I.) a component (A) is used which comprises A1) 5 to 80% by weight of at least one polyester and/or one alkyd resin (A1) having an OH number from 0 to 200 mg of KOH/g, an acid number from 0 to 200 mg of KOH/g and a number average molecular weight of between 500 and 10,000, preferably between 1,000 and 5,000, A2) 95 to 20% by weight of at least one polyacrylate (A2) having an OH number from 30 to 250 mg of KOH/g an acid number from 0 to 50 mg of KOH/g and a number average molecular weight of between 1,000 and 10,000, preferably between 1,500 and 6,000, 26.05.1992 the sum of the weight proportions of components (A1) and (A2) being in each case 100% by weiqht and II.) component (A) is prepared by preparing ........................................ resin (A1), by reaction of a) polycarboxylic acids and/or esterifiable derivatives thereof and, if desired, monocarboxylic acids, 5 to 100 mol% of this carboxylic acid component being cycloaliphatic polycarhoxylic acids and/or esterifiable derivatives thereof, b) polyols, if desired together with monools, c) if desired, further modifying components, and d) if desired, a component capable of reacting with the reaction product from a), b) and, if desired, c), 2.) by preparing at least one polyacrylate (A2), at least some of which has been prepared in the presence of component (A1) obtained in the first process step, using from 5 to 30% by weight, based on the total weight of the monomers employed, of at least one vinvl ester of saturated aliphatic monocarboxylic aaids having 9 to 11 carbon atoms which are branched at the .alpha. carbon atom and REPLACEMENT SHEET

26.05.1992 3.) by adding any polyacrylate (A2) not prepared in the presence of polyester (A1) and, if desired, at least one further polyaddition and/or polycondensation resin.

15. Use of the coating agent as claimed in one of claims 1 to 13 for the refinishing of automotive bodies and for the coating of large vehicles and the coating of truck superstructures.

16. Use of the coating agent as claimed in one of claims 1 to 13 as clearcoat.

REPLACEMENT SHEET