DE3328134C2 - EP powder coatings and processes for producing matt coatings - Google Patents

Abstract

The invention relates to EP powder coatings which are cured by polycarboxylic acids and triacetonediamine (TAD) adducts. The latter are made by reacting TAD derivatives of the formula $ F1 with R1, R2 = H or - (CH2) m-XH, m = 2, 3 and X = O, NH with epoxides, urea, monoisocyanates or optionally partially blocked di- and polyisocyanates obtained. The invention also relates to a process for producing matt coatings with the aid of these powder coatings.

Description

Epoxides of polyunsaturated hydrocarbons, such as. Vinylcyclohexene, dicyclopentadiene, cyclohexadiene-1,3 and -1,4, cyclododecadienes and trienes, isoprene, 1,5-hexadiene, butadiene, polybutadienes, divinylbenzenes and the same,

Epoxy ethers of polyhydric alcohols, such as. B. ethylene, propylene and butylene glycol, glycerine, pentaerythritol, Sorbitol, polyvinyl alcohols and thiodiglycols,

- Epoxy ethers of polyhydric phenols such as resorcinol, hydroquinone, bis (4-hydroxyphenyl) melhanum, Bis (4-hydroxy-3,5-dichlorophenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis - (4-hydroxy-3-rpethylphenyl) propane, 2,2-bis- (4-hydroxy-3,5,5-tricb! Orphenyl) -propane, bis- (4-hydroxyphenyl) -phenylmethane, Bis- (4-hydroxyphenyl) -diphenylmethane, bis- (4-hydroxyphenyl) -cyclohexylmethane, 4,4'-dihydroxydiphenyl, 2,2'-dihydroxydiphenyl,

- N-containing epoxides, such as Ν, Ν-diglycidylaniiine, N ^ '- dimethylglycidyM ^' - diaminodiphenylmethane, triglycidyl isocyanurate.

Epoxides based on bisphenol A with an epoxy equivalent of 500 to 2000 and a melting point of 70 to 140 ^° C. have proven to be particularly suitable.

Suitable polycarboxylic acids for the purposes of the present invention are aliphatic, cycloaliphatic and aromatic carboxylic acids with 2 to 6 carboxyl groups in the molecule and 4 to 20 carbon atoms, such as. B. butanetetracarboxylic acid, Cyclopentanetetracarboxylic acid, mellitic acid and especially pyromellitic acid and trimellitic acid.

The adducts of triacetonediamine (TAD) or its derivatives are characterized by a narrow melting point range the end. You are through implementation of TAD compounds of the formula

CH3 CH3 _Dl

HN> —N (I)

CH ₃ CH ₃ ^R

accessible with the compounds II to V, where R 'and R ^{2 are} independently hydrogen or the radical - (CH ₂ ) ^ - XH, m = 2, 3 and X = 0, NH.

In the event that X is oxygen, it is preferably a derivative which is obtained by reacting TAD with ethylene oxide (m = 2). In the event that X has the meaning of the Nil group, it is preferably the derivative which can be obtained in a simple way from acrylonitrile and TAD and subsequent hydrogenation (m = 3). Finally, R ¹ and R ^{2 can} stand for hydrogen. In this case, TAD itself is the starting product.

The reaction partners of the triacetonediamine derivatives or triacetonediamine just described are as follows Links:

II epoxy resins. In principle, all 1,2-epoxy compounds that have already been mentioned above can be used became. However, epoxy resins based on bisphenol A are also preferred here. The received Adducts have already been described in DE-OS 26 40 410.

III urea. The implementation of TAD with urea is described in DE-OS 26 40 410.

IV Aliphatic or cycloaliphatic diisocyanates with 5 to 12 carbon atoms, in particular isophorone diisocyanate (IPDI), 1 NCO equivalent being used per mole of TAD compound I.

V Partially blocked diisocyanates. These are the same diisocyanates that are already listed under IV became. The blocking agents are phenols and lactams with up to 10 carbon atoms, in particular c-caprolactam. Preferably the isocyanate compound is used with such an amount of blocking agent implemented that the NCO content drops to below 6%.

In the production of the powder coatings according to the invention, customary additives, such as leveling agents, Pigments, dyes, fillers, catalysts, thixotropic agents, UV and oxidation stabilizers, use Find. Common flow control agents are, for example, in patent application P 33 12 028.5 (Page 6, line 23, to page 7, line 12). The amount of these additives can, based on the amount of solid binder, vary within a wide range.

The epoxy resin is made with the polycarboxylic acids and the TAD adducts from I and II in such quantities implemented that per epoxy group an actively bonded hydrogen atom of the hardener mixture for reaction comes. Actively bound hydrogen atoms are on the one hand the protons of the carboxyl groups of the polycarboxylic acids, on the other hand, the hydrogen atoms bonded to nitrogen. A more than 20%, preferably one

Avoid more than 5% excess epoxy resin or hardener mixture. 20 to 90%, preferably 40 to 80% of the actively bonded hydrogen atoms in the hardener mixture should come from the polycai acid component come. It has been shown that the matt effect can be obtained by increasing the polycarboxylic acid content which can strengthen EP powder coatings produced with this hardener mixture. The matt effect can but also influence by varying the polycarboxylic acid.

If a hardener based on a TAD compound of the formula I and urea, isocyanates or blocked isocyanates according to III, IV or V is used, then, based on the total amount of binder (war / and hardener), 6 to 20, preferably 8 to 15 percent by weight hardener.

The powder coatings are produced, for example, by grinding the individual components (epoxy resins, polycarboxylic acids, TAD adducts and, if appropriate, additives), if this appears necessary, mixing them and at 80 to 110 ^° C., preferably 90 to 100 ^° C., extruded. It is then cooled and ground to a grain size of less than 100 μm.

The application of the powder coating to the body to be coated can be done by known methods, z. B. by electrostatic powder spraying, whirl sintering or electrostatic Wirhekinfp.m Λη.; <· Ϊ́ιΐι.> Ιι, .ι - », ι

the coated objects are cured for 35 minutes to six minutes in the temperature range between 170 and 240 ^° C., preferably for 30 to 12 minutes between 180 and 220 ^{° C.}

For coating with the pulverulent coating agents according to the invention, all substrates are suitable which withstand the specified curing temperatures, e.g. metals, glass, ceramics or plastic.

The powder coatings produced in this way are characterized by very good paint properties. It is particularly advantageous that degrees of gloss can be set between semi-gloss and matt.

1. Manufacture of the hardener

10 Example 1.1

To 156 parts by weight of TAD 190 parts by weight of an epoxy resin based on bisphenol-A-based added an epoxide value of 0.5 under intense agitation so that the temperature of the reaction mixture did not rise above 120 ⁰ C at 8O ⁰ C. The mixture was kept at 120 ^° C. for 10 minutes and the reaction mixture was then cooled to room temperature.

M.p .: 70 to 72 ° C

NH (active) equivalent weight: 173

Glass transition temperature (DTA): 46 to 57 ° C

Example 1.2

To 156 parts by weight of TAD 500 parts by weight was added a molten epoxy resin based on bisphenol-A based resin having an epoxide of 0.2 at 120 ⁰ C with intensive stirring. The mixture was heated to 130 ^° C. for a further 15 minutes and then the reaction mixture was cooled to room temperature.

M.p .: 108 to 112 ° C

NH (active) equivalent weight: 328 Glass transition temperature (DTA): 70 to 80 ⁰ C

Example 1.3

To 156 parts by weight of TAD 600 parts by weight of molten epoxy resin based on bisphenol-A based epoxy value of 0.11 was added with a period of 30 minutes at 130 ⁰ C with intensive stirring. The mixture was then held at this temperature for a further 10 minutes, then it was cooled to room temperature.

M.p .: 118 to 123 ° C
NH (active) equivalent weight: 324
Carbon wall temperature (DTA): 75 to 83 ° C

Example 1.4

To 170.4 parts by weight of Aminopropylderivats of TAD (Ri = - (CH _{2) m} -XH, R ₂ = H, m = 3, X = NH) were dissolved in 600 ml of ethanol were added dropwise at 50 ⁰ C, 88.8 parts by weight of IPDI . After a reaction time of 1 hour, the solvent was distilled off and the urea obtained was dried in vacuo.

M.p .: 85 to 87 ° C

Glass transition temperature (DTA): 40 to 54 ° C
NCO content: <0.1 percent by weight

Example 1.5

A mixture of 90 parts by weight of urea and 468 parts by weight of TAD was heated ^{first at 150 °} C. for 3 hours, then at 200 ^{° C. for 2 hours.} The melt was cooled, broken and ground.

M.p .: 200 to 210 ° C

Glass transition temperature (DTA): not recognizable

Example 1.6

To a solution of 133.2 parts by weight of IPDI in 100 ml of acetone 187.2 parts by weight of TAD were zugctropft, wherein the reaction temperature rose to 5O ⁰ C. The precipitated urea was filtered off with suction and dried in vacuo.

M.p .:> 230 ° C

Glass transition temperature (DTA): not recognizable

NCO content: <0.1 percent by weight

Example 1.7

253.7 parts by weight of IPDI were added at 100 ⁰ C in portions with 193.7 parts by weight ^ caprolactam. Mixture was then heated to 12O ⁰ C. After the NCO content had dropped to 5.3 percent by weight, the reaction mixture was heated to 140 ⁰ C and reacted with 60.9 parts by weight of Aminopropylderivats of TAD (see. Example 1.4) to the reaction. The reaction temperature rose to 180 ^° C. in the course of this. After a reaction time of 30 minutes, the melt was cooled, broken up and ground.

SMP .: 82 to 87 ° C

Glass transition temperature (DTA): 58 to 76 ° C
NCO content: <0.1 percent by weight

Viscosity at 130 ^° C.: 17,700 mPas

Example 1.8

As described under 1.7, 333 parts by weight of IPDI were reacted with 254.25 parts by weight of r-caprolactam. After the NCO content had fallen to 5.3 percent by weight, 81.5 parts by weight of the bishydroxyethyl derivative of TAD (R ¹ = R ² = - (CH ₂ ), "- XH, m = 2, X = 0) were added and 3 Held at 120 ^{0 C hours.} The melt obtained was cooled, broken and ground.

M.p .: 72 to 77 ° C

NCO content: <0.1 percent by weight

2. Epoxy resins used

Epoxy resins based on 2,2-bis- (4-hydroxyphenyl) propane (Dian) were used, which according to information of the manufacturer had the following physical data:

2.1 EP equivalent weight 900-1000
EP value 0.10-0.11

OH value 0.34

Melting range 96 to 104 ⁰ C

2.2 EP equivalent weight 1700-2000
EP value 0.05-0.059

OH value 0.36

Melting range 125-132 ° C

3. Manufacture of powder coatings

Example 3.1

590 parts by weight of the ground epoxy resin according to 2.1 are mixed with 33.6 parts by weight of the ground hardener according to Example 1.1.36 parts by weight of trimellitic acid, 60 parts by weight of a 10% leveling agent masterbatch based on polymer! Butyl acrylate in the epoxy resin of 2.1) and 480 parts by weight of TiO ₂ Weilipigment intimately mixed in a pug mill and then homogenized in an extruder at 90 to 100 ⁰ C. After cooling, the extrudate was broken up and ground with a pin mill to a particle size of <100 μm. The powder thus prepared was applied with an electrostatic powder spraying unit at 60 KV on degreased steel panels and baked in a convection oven at temperatures between 180 and 220 ⁰ C.

Stoving conditions Temp. Mechanical Characteristics ET GS Imp. GG GG Time ⁰ C SD HK rev. 60 ° < 85 ° -T Min. 220 2.1-2.5 0 115.2 5 18th 12th 200 70-85 130 1.9-2.3 0 <115.2 6th 20th 18th 200 60-70 140 2.4-3.1 0 230.4 5 16 25th 180 85-95 136 1.9-2.7 0 115.2 5 18th 30th 70-80 138

The abbreviations in this and the following tables mean:

SD layer thickness in; xm

MK König hardness in sec (DIN 53 157)

ET cupping according to Erichsen in mm (DIN 53 156) 5

GS cross-cut test (DIN 53 151)

Imp. Rev. Impact reverse in inch -Ib = 11.52 gm

GG 85 ° < ^{Measurement of} gloss according to Gardner (ASTM-D 523)

Example 3.2

Following the procedure described in Example 3.1 method, a powder coating having the following formulation was prepared applizicrt and baked between 180 and 22O ⁰ C. 15th

720 parts by weight of epoxy according to 2.1

75 parts by weight of hardener according to Example 1.1
600 parts by weight of white pigment (TiO ₂ )

75 parts by weight of leveling agent masterbatch according to Example 3.1 20

30 parts by weight of trimellitic acid

Iinhrcn η conditions Mechanical Characteristics ET GS Imp. GG GG / eil temp. SD HK rev. 60 ° < 85 ° < Min. "C

12 220 60-70 141 5.5-5.9 0 345.6 20 32

18 200 65-80 146 4.3-4.7 0 115.2 18 35 ³⁰

25 200 55-70 144 6.8-7.1 0 460.8 21 34

30 180 60-70 147 3.1-3.7 0 115.2 24 36

Example 3.3

Using the method described in Example 3.1, a powder coating was produced with the following recipe: applied and baked between 180 and 220 ° C.

560 parts by weight of epoxy according to 2.1

87.92 parts by weight of hardener according to Example 1.1
480 parts by weight of white pigment (TiO ₂ )

60 parts by weight of leveling agent masterbatch according to Example 3.1

12.08 parts by weight of trimellitic acid 45

Burning conditions Mechanical Characteristics ET GS Imp. GG GG / eil Tcmp. SD HK rev. 60 ° < 85 ° < Min. ° C

12 220 65-75 159 6.0-6.4 0 230.4 41 53

18 200 60-70 161 5.9-6.3 0 230.4 38 55

25 200 60-80 165 6.5-6.8 0 460.8 43 58 ⁵⁵

30 180 70-80 158 4.7-5.1 0 115.2 42 57

Example 3.4

Using the method described in Example 3.1, a powder coating was produced with the following recipe: applied and baked between 180 and 220 ° C.

691.65 parts by weight of epoxy according to 2.1

95.25 parts by weight of hardener according to Example 1.2 65

600 parts by weight of white pigment (TiO ₂ )

75 parts by weight of leveling agent masterbatch according to Example 3.1

38.1 weight of trimellitic acid

Stoving conditions Temp. Mechanical Characteristics ET Time ⁰ C SD HK Min. 220 3.8-4.6 12th 200 60-70 151 3.1-3.9 18th 200 50-70 160 5.6-6.1 25th 180 60-80 158 4.0-4.2 30th 60-75 161 Example 3.5

GS Imp. GG GG rev. 60 ° < 85 ° < 0 115.2 21 40 0 115.2 24 42 0 345.6 22nd 46 0 115.2 25th 48

Using the method described in Example 3.1, a powder coating was produced with the following recipe: applied and baked between 180 and 220 ° C.

736.5 parts by weight of epoxy according to 72.4 parts by weight of hardener according to example 600 _{parts by weight of white pigment (TiO 2} ) 75 parts by weight of leveling agent masterbatch according to example 16.1 parts by weight of trimellitic acid

25th Stoving conditions Temp. Mechanical Characteristics ET GS Imp. GG GG Time ° C SD HK rev. 60 ° < 85 ° < Min. 220 4.8-5.1 0 230.4 46 59 30th 12th 200
200 60-70 162 3.8-4.1
4.4-4.9 0
0 115.2
345.6 44
45 56
60 18th
25th 180 70-80
60-75 159
164 3.1-3.9
Example 3.6 0 115.2 41 55 35 30th 70-80 160

According to the method described in Example 3.1, a powder coating with the following recipe was produced, applied and baked ^{between 180 and 220 ° C.}

747.7 parts by weight of epoxy according to 61.0 parts by weight of hardener according to example 600 _{parts by weight of white pigment (TiO 2} ) 75 parts by weight of leveling agent masterbatch according to example!

16.3 parts by weight of trimellitic acid

Stoving conditions Temp. Mechanical Characteristics ET GS Imp. GG GG Time ⁰ C SD HK rev. 60 ° < 85 ° < Min. 220 5.8-6.1 0 230.4 40 58 12th 200 60-70 162 4.9-5.1 0 115.2 44 56 18th 200 60-80 165 5.0-6.1 0 345.6 42 59 25th 180 70-80 164 4.1-4.8 0 <115.2 45 60 30th 60-70 168 Example3.7

According to the method described in Example 3.1, a powder coating with the following formulation was produced, applied and baked ^{between 180 and 220 ° C.}

736.5 parts by weight of epoxy according to

72.4 parts by weight of hardener according to example 600 _{parts by weight of white pigment (TiO 2} ) 75 parts by weight of leveling agent masterbatch according to example 16.1 parts by weight of trimellitic acid

Burning conditions Temp. Mechanical Characteristics ET Time ⁰ C SD HK Min. 220 3.5-4.1 12th 200 60-70 184 2.7-3.3 18th 200 50-60 179 3.4-4.8 25th 180 50-70 180 2.1-3.1 30th 60-70 184 Example 3.8

GS Imp. GG GG rev. 60 ° < 85 ° < 0 230.4 59 70 0 115.2 60 74 0 230.4 58 68 0 <1 15.2 62 70

According to the method described in Example 3.1, a powder coating with the following recipe was produced, applied and baked ^{between 180 and 220 ° C.}

736.5 parts by weight of epoxy according to 2.1

72.4 parts by weight of hardener according to example 600 _{parts by weight of white pigment (TiO 2} ) 75 parts by weight of leveling agent masterbatch according to example 16.1 parts by weight of trimellitic acid

Burning conditions Temp. Mechanical Characteristics ET GS Imp. GG GG Time ⁰ C SD HK rev. 60 ° < 85 ° < Min. 220 5.9-6.9 0 460.8 50 61 12th 200 55-65 170 3.5-4.0 0 115.2 55 60 18th 200 50-70 168 4.7-5.5 0 460.8 49 56 25th 180 60-70 174 3.2-3.8 0 115.2 51 59 30th 50-60 173 Example3.9

According to the method described in Example 3.1, a powder coating with the following recipe was produced, applied and baked ^{between 180 and 220 ° C.}

268.65 parts by weight of epoxy according to 2.1 336.15 parts by weight of epoxy according to 2.2 175.2 parts by weight of hardener according to example 600 parts by weight of white pigment (TiO ₂ ) 75 parts by weight of leveling agent masterbatch according to example 45 parts by weight of trimellitic acid

Burning conditions Temp. Mechanical Characteristics ET GS Imp. GG GG Time ° C SD HK rev. 60 ° < 85 ° < Min. 220 2.7-3.1 0 115.2 30th 41 12th 200 60-70 135 2.2-2.9 0 115.2 28 40 18th 200 50-70 141 2.3-3.8 0 230.4 32 45 25th 180 55-80 139 1.9-2.5 0 <115.2 34 43 30th 60-75 144 Example 3.10

Following the procedure described in Example 3.1 method, a powder coating having the following formulation was prepared, applied and baked between 180 and 22O ⁰ C.

560 parts by weight of epoxy according to

87.36 parts by weight of hardener according to example 480 _{parts by weight of white pigment (TiO 2} ) 60 parts by weight of flow control masterbatch according to example 12 parts by weight of promellitic acid

Stoving conditions Temp. Mechanical Identifier I. ET GS Imp. GG GG Time ⁰ C SD HK rev. 60 ° < 85 ° < Min. 220 5.5-5.9 0 230.4 38 50 12th 200 50-70 162 4.0-5.0 0 115.2 35 49 18th 200 60-80 159 6.1-6.7 0 345.6 38 53 25th 130 60-70 164 4.2-4.4 0 115.2 40 56 30th 70-90 165 Example 3.11

Using the method described in Example 3.1, a powder coating was produced with the following recipe: applied and baked between 180 and 220 ° C.

747.7 parts by weight of epoxy according to 61.0 parts by weight of hardener according to example 600 _{parts by weight of white pigment (TiO 2} ) 75 parts by weight of leveling agent masterbatch according to example 16.3 parts by weight of pyromellitic acid

Using the method described in Example 3.1, a powder coating was produced with the following recipe: applied and baked between 180 and 220 ° C.

829.95 parts by weight of epoxy according to 127.5 parts by weight of hardener according to example 450 _{parts by weight of white pigment (TiO 2} ) 75 parts by weight of leveling agent masterbatch according to example 17.55 parts by weight of trimellitic acid

Stoving conditions Temp. Mechanical Identifier I. ET GS Imp. GCi (Xi Time ⁰ C SD HK rev. 60 ° < 85 ° < Min. 220 4.7-5.3 0 115.2 35 53 12th 200 60-80 168 4.0-4.4 0 115.2 38 59 18th 200 50-70 171 4.8-5.7 0 230.4 40 57 25th 180 60-70 170 3.9-4.6 0 <115.2 38 57 30th 65-75 167 Example 3.12

Stoving conditions Temp. Mechanical Characteristics ET GS Imp. GG GG Time ⁰ C SD HK rev. 60 ° < 85 ° < Min. 220 6.5-7.2 0 345.6 45 57 12th 200 50-60 180 4.8-6.1 0 345.6 46 56 18th 200 60-70 182 6.2-7.8 0 576 48 59 25th 180 60-80 184 5.1-5.8 0 230.4 45 57 30th 50-75 179

10

Comparative experiment A

From equivalent amounts of piperidine and an epoxy resin based on bisphenol A with an epoxy equivalent weight of about 900 a piperidine-epoxy resin adduct was produced.

Following the procedure described in Example 3.1 method, a powder coating having the following formulation was prepared, 5 applizicrt and baked at 200 ⁰ C.

456.2 parts by weight of bisphenol A-based epoxy resin with an epoxy equivalent weight of about 900

54.8 parts by weight of piperidine-epoxy resin adduct

39.0 parts by weight of trimellitic acid 10

400.0 parts by weight of white pigment (TiO ₂ )

50.0 parts by weight leveling agent masterbatch

rioietn

Comparative experiment B

Using the method described in Example 3.1, a powder coating was produced with the following recipe:
and stoved at 200 ⁰ C.

501.8 parts by weight of bisphenol A-based epoxy resin with an epoxy equivalent weight of about 900
6.0 parts by weight of piperidine-epoxy resin adduct analogous to Comparative Example A 30

42.4 parts by weight of trimellitic acid
400.0 parts by weight of white pigment

50.0 parts by weight of leveling agent masterbatch

Stoving conditions Temp. Mechanical Characteristics Imp. GG GG Time ° C SD ET rev. 60 ° < 85 ° < Min. 200 460.8 43 56 10 200 70 1.5 691.2 40 54 15th 60-65 2.4

burning conditions Mechanical Characteristics ET GG GG Line temp. SD Imp. 60 ° < 85 ° < Min. ° C rev.

IO 200 55> 921.6 9 61 84

15 200 60> 921.6 8.8 64 82

Claims (1)

Patent claims: 1. Storage-stable powder coatings with a grain size smaller than 100 μΐη based on a mixture of substances, consisting of A epoxide compounds having on average more than one epoxide "roup per molecule and a melting point of about 70 ⁰ C, namely a) epoxides of polyunsaturated hydrocarbons, b) epoxy ethers of polyhydric alcohols, c) epoxy ethers of polyhydric phenols or d) N-containing epoxies, B aliphatic, cycloaliphatic :! or aromatic polycarboxylic acids with 2 to 6 carboxyl groups in the Molecule and 4 to 20 carbon atoms, C derivatives of cyclic amines and D usual additives, characterized in that the derivatives of cyclic amines C are adducts obtained by reaction of triacetonediamine (TAD) or its derivatives (TAD derivatives), the TAD or the TAD derivatives the formula I. have, in which R 'and R ^{2 are} independently hydrogen or the radical (CH ₂ ) ", - XH, m = 2.3 and X = O, NH, have been obtained with one of the following compounds II to V : II aliphatic, cycloaliphatic, araliphatic or heterocyclic epoxides having up to 100 carbon atoms, which contain on average more than one epoxy group per molecule and having a melting point of about 7O ⁰ C, namely a) epoxides of polyunsaturated hydrocarbons, b) epoxy ethers of polyhydric alcohols, tj c) epoxy ethers of polyhydric phenols or * ₍ ^v d) N-containing epoxides, \ · III urea,
IV aliphatic or cycloaliphatic diisocyanates with 5 to 12 carbon atoms, namely in such a \ - Quantity ratio that comes to 1 mol of TAD or TAD derivative of the formula I 1 NCO equivalent, ^ V aliphatic or cycloaliphatic diisocyanates with 5 to 12 carbon atoms, which are replaced by phenols or Lac- $ camouflage with up to 10 carbon atoms are partially blocked. 2. Powder coatings according to claim 1, characterized in that _v 1. The derivative of the cyclic amines C is an adduct based on TAD or a TAD derivative of the formula I is unii of an epoxy according to II and (, 2. to one epoxy equivalent of the epoxy compounds mentioned under A 0.8 to 1.2 NH- and COOII- * Equivalents of components B and C come in. <'< 3, powder coatings according to claim 2, characterized in that an epoxy equivalent of the under A mentioned epoxy compounds 0.95 to 1.05 NH and COOH equivalents of components B and C come. '<4. Powder coatings according to claims 1 to 3, characterized in that the derivative of the cyclic, Amine C is an adduct that by reacting triacetonediamine with the sub-amount of one Epoxy resin based on bisphenol A and an epoxy value between 0.1 and 0.5 has been obtained. 5. Powder coatings according to claim 1, characterized in that the derivative of the cyclic amines C is a Is an adduct obtained by reacting TAD or TAD derivatives of the formula I with isophorone diisocyanate has been obtained, the NCO content of which, if necessary, by blocking with t ^ caprolactam to below 67 «> has been reduced. 6. Powder coatings according to Claims 1 to 5, characterized in that the polycarboxylic acid B is an aromatic one Is tri- or tetracarboxylic acid. 7. Use of the powder coatings according to Claims 1 to 6 for the production of matt coatings, powder coatings being applied to the objects to be coated and within 35 to 6 minutes hardens at 170 to 240 ° C. For some time there has been an increasing interest in powder coatings that give a matt surface. the The reason for this is mostly of a practical nature. Shiny surfaces require a much higher degree of cleaning as matt surfaces. In addition, for safety reasons, ts may be desirable to be strong avoid reflective surfaces. The simplest principle to obtain a matt surface is to apply the powder coating depending on the extent of the desired matt effect smaller or larger amounts of fillers, such as. B. Chalk, finely divided silicon dioxide, Add barium sulfate or incompatible additives such as waxes, cellulose derivatives. These However, additives cause a deterioration in the film properties of the coating. At the beginning of the 1970s, the development of powder paints began, which resulted in different ones Reactivities were used to adjust the matt effect. From the Dutch application 68 06 930 it is known that a matting effect is obtained that the epoxy resin is cured simultaneously with sulfamic acid and at least 2% trimellitic anhydride. DE-OS 21 47 653 describes a powder paint mixture with a matt effect that is produced by mechanical mixing of at least two paint powders of different epoxy resin / hardener systems with differing Melting range is established. The method of DE-OS 22 47 779 is based on a mixture of two paint powder, which is through the Differentiate between the presence and absence of a curing accelerator. In DE-PS 23 24 696 a process for the production of coatings with a matt surface is presented, in which a special hardener - the salt of cyclic amidines with certain polycarboxylic acids - is used comes. In fact, only this process has proven itself due to its excellent technical paint properties be able to prevail in the market; the process flow has since been improved (cf. DE-OS 30 26 455 and 30 26 456). However, the production of the amidine salt remains technically complex because it creates difficulties To control the reaction so that only mono- or disalts are formed. It therefore has no attempts lack of the expensive, organic solvents, dimethylformamide, which are required for salt formation simpler ones, such as water or methanol, to replace. In this case there are intensive drying processes as well laborious micronization of the salts formed is necessary in order to avoid strong fluctuations in the degree of gloss avoid. Of course, you could do without the use of amidine salts and instead use that at the same time Use amidine and the polycarboxylic acid. However, such lacquer powders become coatings with inferior ones physical properties obtained. In DE-OS 26 30 011 a process for the production of coatings with a matt surface is described, in which a solid epoxy resin is reacted with a modified anhydride, which optionally contains ester groups, but contains at least one acid equivalent per anhydride equivalent in the molecule. Acts as a catalyst a tertiary amine, preferably by reacting equivalent amounts of pyrrolidine, piperidine or imidazole is obtained with solid epoxy resins. Our own studies have shown that such adducts, which contain tertiary amino groups, neither alone still mixed with polycarboxylic acids in combination with solid epoxy resins based on bisphenol A. (Epoxy equivalent weight about 170 to 2000) result in matt films with good lacquer properties. Finally, state of the art are EP powder coatings that contain cyclic amines, such as, for example, 2,2,6,6-tetramethyl-4-aminopiperidine (Triacetonediamine, abbreviated TAD, cf. DE-OS 26 40 408) or its derivatives (DE-OS 26 40 410) or with polycarboxylic acids or their derivatives (compare, for example, DE-OS 29 08 700) cured in this way and result in the gloss varnishes. The aim of the present invention was to develop EP powder coatings that produce coatings with a matt effect and the lacquer properties of the films obtained should correspond to the state of the art. The disadvantages of the various methods listed above should be avoided. Powder coatings have now been found which meet this goal and which are described in claims 1 to 6 are described. These consist of epoxy resins, polycarboxylic acids and triacetonediamine adducts, which are described in more detail and the usual additives for powder coatings. The subject matter of this invention is also the method described in claim 7 for producing a matt finish Coatings. The epoxy compounds that can be used have on average more than one epoxy group per molecule a melting point of over 70 ° C. The epoxy compounds can be saturated or unsaturated, aliphatic, be cycloaliphatic, araliphatic or heterocyclic. In detail it concerns