CA1052931A - Powder coating compositions comprising an epoxy-functional copolymer and a crosslinking agent - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Improved powder coating compositions are disclosed which comprise an epoxy-functional copolymer and a cross-linking agent which is a mixture of dicarboxylic acids and polyanhydrides.

Description

105,'~93'1 ~: :
The present invention relates to powder coating compositions.
Powder coating compositions are extremely desirable for use in painting substrates in that they are essentially free of organic solvents conventionally utilized in liquid paint systems. Thus, they give off little, if any, volatile -material to the environment when heat cured.
Powder coating compositions comprising (1) a copolymer of a glycidyl acrylate and other olefinically unsaturated monomers, (2) an anhydride crosslinking agent, and ~3) a polymeric flow control agent were heretofore described in U.S. Patent No. 3,781,379.
Powder coating compositions comprising (1) a copolymer of a glycidyl acrylate and other olefinically unsaturated monomers, (2) a dicarboxylic acid crosslinking agent, and (3) a polymeric flow control agent were heretofore described in U.S. Patent 3,752,870 to Santokh S. Labana, a coinventor herein.
Powder coating compositions comprising (1) a ~-copolymer of a glycidyl acrylate and other olefinically unsaturated monomers, (2) a crosslinking agent comprising a mixture of a monocarboxylic acid and a dicarboxylic acid, ` *
and (3) a polymeric flow control agent were heretofore described in U.S. Patent 3,730,930 to Santokh S. Labana, a coinventor herein.
Powder coating compositions comprising (1) a copolymer of a hydroxy acrylate and other olefinically - unsaturated monomers, (2) a crosslinking agent selected from anhydrides, dicarboxylic acids, and melamunes, and (3) a polymeric flow control agent were heretofore described in ~ - 2 -r~~

~05'~931 Canadian Patent No. 979,136.
It now has been discovered that powder coating compositions having certain unexpected advantages relative to the aforedescribed compositions can be obtained by employing with the epoxy-functional or epoxy-plus hydroxy and/or amide-functional copolymer a crosslinking agent com-prising a novel mixture of dicarboxylic acids and polyanhy-drides.
To avoid repetitious disclosure in this specifica-tion, the term "acrylate" is used herein to include bothesters of acrylic acid and esters of methacrylic acid, i.e., acrylates and methacrylates, except in those instances wherein a specific compound is named.
By employing the dicarboxylic acids and the poly-anhydrides in combination, as hereinafter more fully explained, a decrease in phase separation and an increase in leveling, gel time and adhesion are realized. ~;
Further improvement in the homogeniety of the powders, improved mechanical properties of the coating, good solvent resistance and cure at a lower temperature can be obtained by incorporating about 2 to about 10 weight percent of a hydroxy-functional or an amide-functional monomer in the glycidyl acrylate copolymer.

~ -~

- 2a -, '~ :. .' . : . . .... ... . . .
.

1 Wh~re the ~ole runctlonallty o~ su¢h copolymers

2 1~ epoxy runot~onality, they contaln between about 5 and

3 about 20, prer~rably between 8 an~ 15, welght percent Or

4 a glycldyl eat~r Or a monoethylenlcally unsaturated ¢ar-boxylla a¢ld, ~.g., glycldyl acrylate and glycldyl meth-6 aarylate. These monomers provlde the ¢opolymer wlth lts 7 epo~y ~unctlonallty. The r~malndor Or the copolymer con-8 ~18t~ e~sentlally Or monorunctional, alpha-beta ole~lnl-9 oally un~aturstod monomer~. These ¢an be acrylates or a mlxture o~ a¢rylat-~ and mono~lnyl hydrocarbon~. Pro-11 rerably, ln exoc~ o~ ty (50) welght percent o~ the 12 copolymer monomer~ are ester~ Or a Cl - C8 monohydrlc 13 aloohol and acryllc or methacryllc acld, l.e., methyl 14 methaorylate, othyl acrylate, butyl acrylate, butyl meth-acrylate, hexyl acrylata, and 2-ethyl hexyl metha¢rylate.
16 C8 - Cg monovlnyl hydrocarbons such as styrene, vinyl toluene, 17 t-butyl ~tyr-ne, chloro~tyrene and alpha methyl styrone arc 18 ~ultable ~or uso but pr~erably comprl~e 1088 than ~lrty ~50) 19 u~lght peroent o~ the copolymer. Other vlnyl monomers such ac ~inyl chlorlde, aorylonltrile, methaorylonltrlle, and 21 vlnyl ao~tate may be usod a~ modl~ylng monomer~. When em-22 ploy-d, thoso aomprl~o b-tween O and 30% by welght o~ the 23 monomer ml~tur-.
24 Th~ poxy-~unatlonal and amlde-runctional oopolymers whloh ar~ u~ed ln one mbodlm~nt o~ thls lnventlon are pre-26 parod ln the same mann~r a~ the 801ely epoxy-runctlonal C0-27 polym~r~ wlth th~ ~lnglo dl~r~reno- that, ln addltlon to the 28 5 to 20 w~lght p~ra-nt glyaldyl aorylato componont, tho monomor 29 mlx u~d ln tha oopolymarl~atlon al~o aontaln~ about 2 to about 10 wolght paroent Or an alpha-beta olc~lnlcally un~aturatod 31 amldo, .g., aorylamld- or methacrylamlde. Thls 2 to 10 welght 32 poro-nt roplaoo~ tha ~qu~valont amount o~ sald r-malnd~r monomoro.

LN~ 3 105'~931 1 The epoxy-runctlonal, hydro~y-runctlonal monomer~
2 whlch are u~ed ln another embodiment Or thls ln~entlon are 3 pr-pared ln the ~ame manner as the solely epo~y-runctlonal 4 copolymer wlth the ~ln~le dlrrerence that, ln addltlon to the 5 to 20 peraont gly~ldyl acrylate component, the monomer 6 mlx u~-d ln the copolymer~zatlon also contains about 2 to about 7 10 welght percent Or a hydroxy acrylate 8 Tho hydroxy aorylato 18 pre~erably an eater o~ a 9 C2 ~ C3 dlhydrla aloohol and acryllc or m-thacryllc acld N or the~e J 2-hydroxy-thyl methacrylate and 2-hydroxypropyl 11 methaorylate are mo~t prererred Thl~ 2 to 10 welght per-12 aent replaae~ the equlvalent amount o~ sald remainder monomer~
13 Thus, the copolymer ln a rlr~t embodlment comprl~es 14 about 5 to about 20 welght pcrcent o~ a glycldyl acrylateJ
to 30 welght percent Or sald modlrylng monomer~J and about i~
16 50 to about 95 welght percent Or sald remalnder monomers When 17 sald modlrylng monomers are not employed there are about 80 to 18 about 95 welght percent Or sald remalnder monomers employed ~9 In other embodlment~, the aopolymer ¢omprlses about 5 to about 20 welght percent Or a Rlycldyl acrylate, about 2 to about 10 21 welght peroent o~ an ole~lnlcally un~aturated amlde or a hy-22 droxy acrylate or a mlxture thereo~, 0 to 30 welght percent Or 23 ~al~ modl~ylng monomer~, and about 40 to about 93 welght per-2~ o-nt Or ~ald remalndor monomer~ When sald modi~ylng monomer~
are not employed, the monomor mlx ln the~e embodlment~ ln-26 cludea 70 to about 93 welght percent Or ~ald remalnd-r monomer~
27 Where le~ than about 2 wolght peroont o~ the monomer~
28 rormlng the oopolymer are a hydro~y acrylate or an un~aturatod 29 aml~e, ~uoh oo~olymer~ ~hould be aon~ldored to be ~unctlonally qulvalont to the ~ir~t embodl~ent wherein the runotionallty Or 31 the oopolymer 1~ ~ol-ly epoxy 1052931;
1 The~c aopolymer~ have a gla~ tran~ltlon tem-2 p~ratur~ ln the range Or 40C to 90C , prererably 3 betweon 50C and 80C , and a mole¢ular welght (~n) ln 4 the range o~ about 1500 to about 15,000, pre~erably about 2500 to about 6,000 6 When dlaarboxyllc acldo have b~en u~ed a~ th-7 ~ol~ cro~llnklng agont ~or epo~y-~unatlonal copolymers, 8 lt has been round ad~antagaous to employ the aald ln an 9 amount such that about 0 3 to about 1 2 carboxyl groups aro pre~ent ror eaoh epo~y group ln the copolymer 11 In thl~ ln~ontlon, a portlon Or the dlcarboxyllc 12 acld oro~lln~lng agent 18 replaced by a ~unctlonally equlva-13 lent amount Or a polyanhydrlde Thu~, a mlxture o~ the pre-14 polymer and cro~ nklng agent ln accordance wlth thl~ lnventlon ad~antageou31y con*aln~ the dlcarboxyllc acid ln an amount ~u~-16 riclont to pro~ld- about 0 1 to about 0 6 carboxyl 8rouPs por 17 ~unctlonal group on the prepolymer and the polyanhydride ln 18 an amount ~u~rlclent to provid- about 0 2 to about 1 1 an-19 hydri~e groups por same The~e powd-r ~oatlng composltlons lnclude a~ cro~s-21 llnklnR ag nts ror tho a~orede~arlbed oopolymer~ ~aturated, 22 atralght ohaln, allphatlc, dl¢arboxyllc aold contalnlng 4 to 23 20 aarbon atom~ por molocule 24 The pro~erred dlcarboxyllc aolds aro tho~e con-talnln~ ~rom 5 to 13 ¢arbon atoms per molecule In ~tlll 26 groater dotall, the mo~t de~lrable acld~ are adlplo acld, 27 pimellc acld, ~uborlo aald, azelala aald, ~eba~lc acld, 28 undeoanola aald and braa~yllc aoid 29 The pro~orred polyanhydrlde~ are poly ~adiplo Fnhgdrlde), poly (azclala anhydrlde), and poly (~eba~lc ' . ' ' ' ' ' ~ LNS 3 ~OSZ93~
1 anhydrlde) but other~ ha~lng molecular welght up to about 2 5000 are u~erul. Tho~e havlng molecular welght ln the 3 range Or about 1,000 to about 2500 are prererred.
4 These po~dor coatlng compo~ltlon~ advantageously oontaln a rlow ¢ontrol agent aa a part o~ the powder coatlng 6 mlxture. The rlOw oontrol agent 1~ a polymer havlng a 7 molecular welght ~n) ~ at least 1000 and aomprlses at 8 loast 0.05 wel~ht peraont o~ the ml~ture. The rlow aontrol 9 agent has a gla~ transltlon temperature at loa~t 20 C. below the glass tran~ltlon tomperature Or tho mlxtur-'~ copolymer. ~ t 11 One group Or ~ultable rlow control agent~ are 12 aorylla polymer~. Prererred aaryllc polymers whlah may be 13 u~ed ~or the rlow aontrol agent aro polylauryl acrylate, 14 polybutyl aarylato, poly (2- ethylhexyl acrylate), polylauryl metba¢rylate and polylsodeayl methacrylste.
16 The rlow aon~rol agent may also be a rluorlnated 17 polymor ha~ing a ~ur~ace tenslon, at the baklng temperature 18 Or the powder, low~r than that Or th- ¢opolymer utlllzed ln 19 the mlxture. Prorerred rlow control agents, ir the agent 18 a ~luorlnatod polymer are estors Or polyethyloneRlycol or 21 polypropylen~glyool and rluorlnated ratty aclds. Por example, 22 an ~ter Or polyethyleneglycol o~ molecular welght Or over 23 2500 and p~rrluoro octanolc acld i8 a userul rlow oontrol 24 agent. Polymer ~iloxanec Or molecular welght Or o~er 1000 (advantageou~ly 1,000 to 20,000) may also be use~ul as rlow 26 control agent~, e.g. poly (dlmethyl ~lloxane) or poly (methyl-27 phonyl) ~iloxane.
28 A coatlng composltlon ~ormed in aacordanao wlth the 29 toachlng~ o~ thls lnv~ntlon may inalude a small welght peraent Or a catsly~t ln order to lncrea~e the cros~linkin~ rate Or the -~052931 1 powder coatlng composltlon at the baklng temperature 2 thereor. Baklng ~emp~ratures wlll ordlnarlly be ln the 3 range Or 130 to 200C. and the catalyst should produce a 4 ~el tlme ~or the powder coatlng composltlon at the baking temperature to be used whi¢h 18 at least 1 mlnute but no 6 greater than 20 mlnutes. m 1~ gel tlme 18 prererably ln 7 the range o~ l to 12 mlnute~ and most prererably between 8 about 2 and about 8 mlnute~
9 Some catalysts whlch are suitable ror use ln the powder coatlng compo~itlons lnclude tetraalkylammonlum salts, ll lmldazole type catalyst, tertlary amines and metal salt~ Or 12 organlc aarboxyllc aclds. The tetraalkylammonium ~alt 13 cataly~t~ lnclude the ~ollowlng: tetrabutyl ammonium chloride 14 tbromlde or lodlde), tetraethyl ammonlum chloride (bromlde or lodlde), trlmethylbenzylammonlum chlorlde, dodecyl dlmethyl 16 (2-phenoxyethyl) ammonlum bromlde, dlethyl (2-hydroxy ethyl) 17 methyl ammonlum bromlde. Sultable catalysts Or the lmldazole 18 typo lnclude: 2-methgl-4-ethyl lmldazole, 2-methyl lmldazole, 19 imldazole, 2 - C(N-benzylanlllno) methyl] - 2 - imldazoline pho~phate, and 2 - benzyl - 2 - lmldazollne hydroohlorlde.
21 Sultable tertlary amine oatalyst~ ~or the powder coating com-22 po~ltlon~ of thls ln~entlon include: triethylenediamlne, N,N -23 diethylcyclohexylamlne, and N-methyl morphollne. The metal 24 ~alt~ o~ organlc carbo~yll¢ acid whlch are cataly~ts ~or the powder coatlngs o~ thl~ lnvention lnclude, but are not llmlted 26 to: stannous octoate, zln¢ naphthenate, cobalt naphthenate, 27 zinc octoate, ~tannou~ 2 - ethylhe~oate, phenylmercurlc pro-28 plonate, lead neodecanoate, dlbutyl tln dllaurate and llthlum 29 benzoate.
The catalyst used in an lndivldual powder coatlng 31 compo~ltlon i~ generally solid at room temperaturc and has a 32 melting polnt o~ ~rom 50C. to 200C.

; , - .~ ,. . .. ..... . ..

~ LNS 3 ~OSZ931 1 Conventlonal non-metalllc and metalllc plgments 2 aan be us~d wlth th~so powd~r aoatlng compo~itlons. Such 3 are conventionally ~mployed ln an amount 3uch as to con-4 stitute between about 6 and 35 welght percent Or the total mlxture dependln~ on the plgment selected and the gloss re-6 qulred ror the baked coatlng.
7 Slnoe lndlvldual powder aoatlng aompo~itlons o~
8 thls ln~entlon can be applled to an artlcl¢ to be palnted 9 by electrostatl¢ method~, one may de~lre to lnolude a ~mall welght percenta~o o~ an antl~atl¢ agent ln ~uch compo~ltlons.
ll In partlcular, the antlstatla agent 1~ lncluded ln a range 12 rrom 0.05 welght percent Or the total powder ¢omposltlon.
13 Sultable antlstatlc agents include, but are not llmlted to, 14 tetraalkylammonlum salts as dl~cussed prevlously and whlch al~o serve as cataly~ts. Other sultable antlstatla agent~
16 lnalude: alkyl-poly (ethylen~o~y) phosphate or alkylauryl 17 poly tethyleneoxy) phosphates a~, ror example, ethyl benzyl 18 poly (ethyleneoxy) phosphate; polyethylenel~lne, poly (2-vlnyl l9 pyrollldone), pyrldlnlum ahlorlde, poly (~lnyl pyridlum ahlorlde), polyvlnyl alcohol or lnorganic salts.
21 A pla~tlclz~r may be used ln a powder coatlng 22 composltlon Or thls lnventlon lr deslred. The type Or pla~-23 tlaizers used very orten lnclude adlpates, pho~phates, 24 phthalat-~, ~ebacate~, polyester~ derlved rrO~ adlpic acld or azelalc aald, and epoxy or epoxldl~ed pla~tlclzers. Some Or 26 these plastl¢lzers ar~: dlhexyl adlpate, dll~ooatyl adlpate, 27 dlayclohe~yl adlpate, trlphenylpho~phate, trlcre~ylpho~phate, 28 trlbutylphosphate, dlbutylphthalate, dloatylphthalate, butyl 29 oatyl phthalat-, dlo¢tyl sebaoate, butyl benzyl sebaaate, 3~ dlbenzyl ~ebacate, butanedlol - 1,4 - dlglycldyl ether, dl-31 glyoldyl ether o~ bl~phanol A and lt~ polymer~ and oellulose 32 aa-tate butyrate.

;
.: . , ' . : .

-~ LNS 3 ~o5Z931 1 Havlng des¢rlbed the varlou~ materlals whlch are 2 employed ln rormulating the powder coatlng composltlons Or 3 thls lnvention, a plurality o~ examples are herelnarter ~et 4 rorth to lllwtrRte variou~ ln~ivldual powder coatln~ com-po~lt~on~.
6 Example 1 7 An epo~y-runctlonal copolymer 18 prepare~ rrom the 8 below llsted components ln the manner herelnarter set rorth:
. Percent ~y W lght 9 Reactants Amount~,grms. or Tot~l ~ aotant~
glycidyl methacrylate 30 15 11 butyl methacrylate 90 45 12 methyl methacrylate80 40 13 The above mentloned monomers are adml~ed ln the 14 proportlon~ above 3et ~orth and 10.0 gram~ o~ 2,2' - azobl~ -(2-methylproplonitrlle), herelnarter ¢alled AIBN, (5S based 16 on co~bined welght~ Or reactants) are added to the monomer 17 mlxture. The ~olutlon t ~ added dropwl~e over a 3 hour perlod 18 lnto 200 ml toluene at 108 - 111C. under nltrogen atmo~phere.
19 A aonden~er 1~ pro~ld-d at the top Or the toluene contalner to oonden~e the toluene vapors and return the ¢ondensed toluene 21 to the contalner. Then 0.2 Bram~ Or ~IBN dls~olved ln 15 ml 22 aaetone are adaed o~er one-halr hour perlod and rerluxlng 18 23 contlnued ror 3 addltlonal hourJ.
24 The polymer ~olutlon 18 dlluted wlth 200 ml acetone and coagulated ln 2 llter~ Or hexane. The whlte powder 18 26 drled ln a ~acuum oven ror 24.0 hours at 55C. The molecular 27 welght Or the re~ultant copolymer, herelnarter termed Copolymor 28 I, 1~ M /M ~ 6050/3150 tmol wt. per epoxy group or WPE --1000) ~ n 29 and lt~ gla~ tranaltlon temperature, h~rolna~ter rererred to a~ Tg 1~ 48C.

', 105'~931 1 Thls dry oopolymer 18 ml~ed wlth the rollowlng 2 lngredlent~ in the proportions hereina~ter set rorth to 3 ~orm a coatlng powdcr.
4 Ingredlent~ Amounts, grams Copolymer I 50.0 6 Poly ta~elalc anhydrlde) 4.7 7 Azelalc a¢ld 2.35 8 Tltanlum dlo~lde 4.50 9 Ferrlte yellow 4.0 Poly (2-ethylhexyl aorylate) 0.42 11 Mn 9 12 This mlxture iB ball-milled ror 5 houra and mlll-13 rolled ror 10 mlnute~ at 110C. Sub~¢quently, the coolod 14 materlal 1~ granulated and oonvert~d to a partlcle slze range o~ 5 - 30 mlcrona wlth a ~luld energy mlll. Thls powder demon-16 ~trates esaellent non-caklng chara¢terl~tlcs, is unlrorm ln 17 appearance, and demon~trates a hlgh gel tlme o~ 4 mlnutes at 18 175C.
19 Thls powder 1~ ~prayed electro~tatlcally on a grounded ~teel panel by u~lng electrostatlc po~der spray gun 21 operat~ng at 50 KV charglng voltage. The powder coatlng 22 panel~ are cured at 160C. ror 20 mlnutes.
23 m e cured aoatlngs have good adheslon on the ~teel 24 panel~. They alao ha~e good lmpact strength and are not ~oluble ln ~ylene, toluene, methyl ethyl ketone, and gasollne. Thelr 26 appearance 18 ~aellent and are ~ree Or orange peel.
27 E~ample 2 28 m e copolymer Or E~ample 1 la mi~ed wlth the rol-29 lowlng lngredlent~ ln the proportlon~ herelnarter ~et ~orth to rorm a coatlng powder.

~05'~931 Ingredients Amounts, grams Copolymer I 50.0 Poly (azelaic anhydride) 5.0 Azelaic acid 2.6 Titanium Dioxide 4.5 Ferrite yellow 4.0 Poly (lauryl acrylate) (Mn = 8000) 0.5 All components were ball-milled for 4 hours and mill-rolled for 10 minutes at 110C. The material is then granulated and pulverized to a particle size range of 15 - 30 microns~ This powder is uniform, non-caking and has a high gel time~
The coatings are sprayed on steel panels and cured as in the preceding example. On melting, the coating leveled very well and gelled in 4.5 minutes at 175C. The solvent resistance of these coatings-in xylene, toluene, methyl ethyl ketone, and gasoline i5 excellent. The impact strength of these coatings is very good.
Example 3 Powder coating materials of Example 1 including the copolymer and all other ingredients was dispersed in 45 mls and reduced with acetone to a homogeneous mixture containing 30% total solids. After processing this mixture with a spray dryer, a powder is obtained that contained less than 1.5 solvent.
This powder is deposited on steel panels as in Example 1 and cured at 160C. for 25 minutes. The resulting coating has good solvent resistance and appearance.
Example 4 ~ -The procedure of Example 1 is repeated with the following differences: (1) the composition of the copolymer, ~C - .

105'~931 hereinafter called Copolymer II, is formed fro~ and contains the following monomers: -:

- lla - -~

- ., '' ' ' ' ' ,- , , ~ ' -~ LNS 3 105;~931 Percent By Weight 1 Reactants Amount,Grams O~ Total Reactants 2 glyaldyl methacrylate 10 5 3 butyl methacrylate90 45 4 methyl methacrylate 100 50 The~e are polymerlzed with using 1.60 Rrams Or AIBN.
6 (2) In the compoundlng Or the ¢oatlng materlals, the ~ollowlng 7 lngredlent~ are used ln the rollowlng proportlon~:
8 In~redlents mount~, grams g Copolymer II 50 Poly (azelalc anhydrld~) 3.0 11 Azelalc acld 0.5 12 Tltanlum dloxlde 4.50 13 Ferrlte yellow 4.0 14 Poly (2-ethylhe~yl acrylate) 0.42 The coatlng~ exhlblt a hlgh gel time, good 16 appoarance and good adhe~lon.
17 Exampl 18 The procedure o~ Example 1 18 repeated e~cept 19 that a runctlonally equlvalent amount o~ glycldyl acrylate ls ~ubstltuted ~or the glycldyl methacrylate used to rorm 21 the copolymer.
22 Example 6 ~, 23 The proc~dure o~ Example 1 ls repeated except ~or 24 the dlr~erenae that a ~unctionally equlvalent amount Or adlpic acld 1~ sub~tltuted ~or the azelalc acld ln the coatlng 26 materlal ~ormulatlon.
27 Example 7 28 The proce~ure Or Example 1 ls repeated e~cept ror 29 the dlr~erence that a unctlonally equlvalent amount Or plmellc acld 18 ~ub~tltuted ror tho azelalc acld ln the coatlng materlal 31 ~ormulatlon.

~- LNS 3 Example 8 l The pro¢edure Or Examplc l i8 repeated except ror the 2 dlr~erence that a runctlonally equlvalent amount Or 3uberlc acld 3 1B ~ubstltuted ror the azelal¢ acld ln the coatlng materlal 4 rormulatlon.
Example 9 6 Th~ procedur~ Or Example 1 1~ repeated ex¢ept ror the 7 dlrrerence that a runctlonally equlvalent amount Or sebaclc acld 8 1~ ~ub~tltuted ror thc azelalc acld ln the coatlng materlal 9 rormulatlon.
Example lO
ll The procedure Or Example l ~ repeated except ror the 12 dlrrerence that a runctlonally equlvalent amount Or undecanolc 13 acld 18 substltuted ror the azelalc acld ln the coatlng materlal 14 rormulatlon.
Example ll 16 The procedure Or Example l 18 repeated except ror the 17 dlrreren¢e that a runctionaily equlvalent amount Or bra~syllc 18 acid 1~ ~ub~tltuted ror the azelalo acld ln the coatlng materlal 19 rormulatlon. , Example 12 21 The procedure o~ Example l 1~ repeated exoept ~or the 22 dlrrerence that a runctionally equlvalent amount Or poly 23 (adlplc anhydrlde) 18 ~ub~tltuted ror the poly tazelalc an-24 hydrlde) ln the coatlng materlal rormulatlon.
Example 13 26 The procedure Or Example 1 18 repeated except ror the 27 dlrreren¢e that a ~unctlonally equlvalent amount Or poly (~e-28 basi¢ anhydrlde) 18 ~ub~tltuted ror the poly (a&elalc anhydrldo) 29 ln the coatlng materlal ~ormulatlon.

105'~931 ~xamplc 14 1 The procedur~ o~ Example 1 1~ repeated e~cept for 2 the preparatlon Or the copolymer and the composltlon Or the 3 camplete coating materlal. In thls e~ample, the preparatlon 4 Or the copolymer, herclnarter called Copolymer III, rollows the preparatlon Or Copolymer I except rOr the changes hereln-6 a~ter ~et rorth:
Per¢ent By Welght 7 Reactants Amounts, grams 0~ Total Roactant~
8 glycldyl methacrylate 45 15 9 acrylamlde 15 5 butyl methacrylate lll 37 11 methyl methacrylate129 43 -12 In thl~ polymerlzatlon, ll.0 grams Or AIBN are used, 13 the monomer mlxture 18 added through a regulatlng ~alve and 14 the rate Or additlon i~ contro}led to malntaln a reactlon temperature Or 90 - 110C. wlth the rest o~ the heat supplled 16 rrom an e~ternal heater. Arter the addltlon Or the monomer 17 mlxture i8 completed (3 hours), 0.8 grams o~ AIBN dlssolved 18 in lO ml acetone 1~ added over a one halr tl/2) hour period l9 and rerluxlng ls contlnued ~or two (2) addltlonal hours.
The resultant toluene-polymer solutlon 18 dlluted 21 wlth 200 ml~. acetone and coagulated in 2 llters Or hexane.
22 The whlte powder 1~ drled ln the vacuum o~en at 55C. ror 24 23 hour~. Its molecular welght 1~ determlned to be M /M - 6700/3200 24 ~ and WPE (molecular weight per epoxlde group) 18 about lO00.
The coatlng materlal ha~ the ~ollowlng composltlon:

lOSZ931 l 1 Ingr~dlent~ Amounts, grams 2 Copolymer III jO.0 3 Poly (azelal¢ anhydride) 4.8 4 Azelaic acld 2.4 Tltanlum dloxlde 4.50 6 Ferrlte yellow 4.0 7 Poly (2-ethylhexyl acrylate) Mn~llO00 0.42 8 . . Example 15 9 The procedure Or Example 14 1~ repeated except rOr the dl~reren¢e~ that the composltlon Or the copolymer and the 11 compo~ltlon Or the ¢omplete coatlng materlal dlrrer as herein-12 arter set rorth.
13 . m e compo~ltlon Or the copolgmer, herelnarter called 14 Copolymer n~ l~ as ~ollow~:
Percent By Welght ReactantsAmountsJ gram8 or Total Rea¢tants 16 ~lycldyl methacrylate 45 15 17 methacrylamlde 6 2 18 butyl methacrylate120 40 ~-19 methyl methacrylate129 43 The composltlon Or the coatlng materlal Or thl~ :
21 examplc 18 as rollow~:
22 }n~redlents A o nts, gram~
23 Copolymer N 50.0 24 Poly (azelalc anhydrlde) 8.5 Azelalc acld 1.1 26 Tltanlum dloxlde 4.50 27 Ferrlte yellow 4.0 28 Poly (2-ethylhcxyl a¢rylate), ~n~9000 0.42 29 - Example 16 The procedure Or Example 14 1~ repoated except ror the 31 dlrrerences that the composltlon Or the copolymer and the compo-32 sltlon Or the ¢ompletc coatlng materlal dlr~er as herelnarter 33 ~et rorth.

.

~05'~931 1 The compo~ltlon o~ the copolymer, herelna~ter 2 called Copolymer V, 18 as ~ollow~:
Pcrcent By Weight 3 ReactantJ Amount~, 8rams0 ~otal Rea¢tants 4 glyaldyl methacrylate 16 8 methacrylamlde 20 lO
6 butyl methacrylate 84 42 7 methyl methacrylate 80 40 8 The compos~tlon o~ the coatlng materlal in thl~
9 example 18 as ~ollows:
In~redlent~ ~~ E~
ll Copolymer V 50.0 12 Poly (azelalc anhydrlde) 3.0 13 Azelaic acld 1.6 14 Tltanlum dlo~lde 4.50 Ferrlte yellow 4.o 16 Poly t2-ethYlhexYl acrylate)~ M ~llO00 0.42 17 Example 17 18 The procedure Or Example l 18 repeated except ror -l9 the preparation o~ the copolymer and the composltlon Or the complete coatlng materlal. In thls example, the preparatlon 21 Or the copolymer, herelnarter called Copolymer VI, ~ollows 22 the preparatlon o~ Copolymer I except ror the changes hereln-23 a~ter set rorth.
Percent By Welght 24 Reactant~ Amount~, grams 0~ Total Rea¢tants gly¢ldyl metnacrylate 30 15 26 hydroxyethyl methacrylate 10 5 27 butyl methacrylate 80 40 28 methyl methacrylate 80 . 40 -,, . . - .

105'~931 l In thl~ polymerizatlon, ll.0 grams Or AIBN are 2 employed. Th~ mlxture 1~ ~lowly added to 200 ml Or toluene 3 heated to 80 - 90C. whl¢h 1~ belng stlrred vlgorously under 4 a nltrogen atmosphere. A condenser 1~ provld~d at the top Or the toluene contalner to aondense the tolueno vapors and re-6 turn the ¢onden~cd toluene to the contalner. The monomer 7 ml~ture 18 added through a regulatlng ~alve and the rate o~
8 addltlon 18 controlled to malntaln a reactlon temperature Or 9 90 - 110C. wlth the rest o~ the heat supplle rrom an ex-ternal heater. Arter the addltlon o~ the monomer mixture 1 11 complet~d (3 hours), 0.8 grams Or AIBN dl~solved ln lO ml 12 acotone 1~ added over a one halr (1/2) hour perlod and re-13 ~luxlng 1~ aontlnued ~or two (2) addltlonal hours.
14 The reaultant toluene - polymer solutlon 18 dlluted wlth 200 mls acetone and coagulated ln 2 llters Or hexane.
16 The whlte powder 1~ drled ln the racuum oven at 55 C. ~or 24 -17 hour~. Its mol~ular welght ls determlned to be M /M
18 6700/3200 and WPE (molecular welght per epoxlde group) 18 l9 about 1000.
The compo~ltlon o~ the ¢oatlng materlal ~n thls 21 example 1~ a~ rollow~:
22 In~redlent~ Amounts, grams 23 Copolymer VI 50 24 Poly (azelalo anhydrlde) 5.0 Azelal¢ acld 2.1 26 Tltanlum dloxlde 4.50 27 Ferrlte yellow 4.0 28 Poly (2-~thylhexyl acrylate) 0.42 ~05'~931 l Example 18 2 The proceduro o~ Example 17 ls repeatod e~cept ror 3 the dirrerenae~ that the composltlon Or the copolymer and the 4 composltlon Or the ¢omplete aoatlng materlal dlrrer as hereln-a~ter set ~orth:
6 The aomposltlon of the copolymer, horelna~ter oalled 7 Copolymer VII, 1~ a~ ~ollow~:
Poraent ~y Welght 8 Reactants Amounts, gram3 or Total Roaatants :~-9 gly¢ldyl methacrylato . 30 15 hydrosyethyl metha~rylate 4 2 ll butyl metha¢rylate 80 40 i2 methyl methaarylate 86 43 ~.
13 ~he aomposltlon o~ the aoatlng materlal ls a~
14 ~ollows:
In~redients A ounts, ærams --16 Copolymer VII 50.0 17 Poly (azelala anhydride) 4.7 18 Azelala acld 2.35 l9 ~ltanlum dloxlde 4,50 Forrlte yellow 4.0 21 Poly (2-ethylhexyl acrylate) 0.42 22 Example 19 23 The proceduro o~ Examplo 17 1~ repeated exaept 24 ~or tho dlr~erenae~ that the aomposltlon Or tho oopolymer and the composltlon o~ tho complete ooatlng material dlrrer as 26 horeina~tor set rorth:
27 The ¢omposltion o~ the aopolymer, herelnarter 28 aalled Copolymer ~III, 1~ a~ ~ollows:

~05'~931 Per¢ent By Welght 1 Reaat_nt~ 9l_E~9e~or Total Reactants 2 glyoldyl methacrylato 30 15 3 hydroxyethyl metbacrylate 20 lO
4 butyl mothaorylate 80 40 m~thyl methaorylato 70 35 6 The ¢ompo~ltlon Or the ooatlng ~aterlal 18 as 7 rOllow8:
8 Ingredlents A~g~t~_E
9 Copolymer VIII 50 0 Poly (a~olale anhydrlde) 4 4 il A~-lale a¢ld 1 4 12 Tltanlum dloxlde 4 50 13 Ferrlto yellow 4 0 14 Poly (2-ethylhexyl aerylate) 0 42 _xample 20 16 The proc-dures Or ~xample 17 are ropeated ex¢ept l? ror tho dl~rorenee that a chemlcally equlvalent amount Or 18 hydroxyethyl a¢rylate 18 ~ub~tltuted rOr the hydrosyethyl l9 methaorylat- componont o~ Copolymer VI
Examp1o 21 21 Tho proeodure~ Or Example 17 are ropeat-d exoept 22 ~or the dlrreren~o that a ohemloally equlvalent amount or 23 hydroxypropyl aarylato 1~ sub~tituted rOr the hydroxyothyl 2~ mothaorylato oomponont Or Copolymer VI
~
26 Tho proo-duro~ Or Example 17 aro ropoated except 27 ror the dlrrorcneo that a cheml¢ally equlval-nt amount Or 28 hydroxypropyl m-thaerylato i~ ~ub~tltutod ror the hydroxy-29 othyl methaorylato oo~ponont Or Copolymer VI

.

105'~93~
1 Examplo 23 2 The prooedures Or E~amples 1, 14 and 17 are 3 repeated wlth the slngle dl~rerence that an equl~alent amount -;
4 Or poly (butyl acrylate) (M -9000) 18 ~ubstituted ror the poly (2-ethylhexyl aarylate) rlow aontrol agent 6 E~ample 24 7 The procedur-~ Or E~ample~ 1, 14 and 17 aro 8 repoated wlth the ~ingle dlrrerence that an equlvalent amount 9 Or poly (lauryl methacrylate) ~Mn-6000) 18 sub~tituted ~or the poly (2-ethylhe~yl acrylato) rlow control agent 11 Exampl~ 25 12 The procedure~ Or E~ample~ 1, 14 and 17 are 13 repeated with the ~lngle dlrrerence that an equivalent 14 amount Or poly (i~odeayl methacrylate) ~n'5~ ubstituted ror th~ poly (2-ethylhe~yl acrylate) rlow control agent 16 E ample 26 17 The prooedure~ Or E~ample~ 1, 14 and 17 are 18 repeated wlth the sin~le dlrrer~nce that an oqulvalent amount 9 Or polyethylone glyaol perrluoro octonoate - hn~3400 1~ ~ub-~tltuted rOr the poly (2-othylhe~yl acrylate) rlow control 21 ~gent 22 E~ample 27 23 The prboe~uro~ Or Example~ 1, 14 and 17 are 2~ repeated wlth tho ~ingle dirrerenco that an equival~nt amount Or poly (methyl ~ilo~ane) 1~ sub~tltuted ror the 26 poly (2-cthylho~yl acrylato) rlow control agent 27 E~ample 28 28 m e proaedure~ Or E~ample~ 1, 14 and 17 ar- r-p-atod 29 wlth tho ~lngle ~lrrerenae that the rlow control agent, poly (2-ethylho~yl aarylate), 1~ reduood ~rom 0 42 grams to 0 25 31 grams ~05;~931 1 Example 29 2 The procoduroæ Or Examples 1, 14 and 17 are 3 r-p~ated with the slngle dlrrerence that the rlow control 4 agent, poly (2-ethylhe~yl a¢rylatc), 1~ ln¢reased rrom 0.42 grams to 0.75 ~ram~.
6 Example 30 7 The prooeduros o~ Examplos 1, 14 and 17 are 8 repeated wlth the slngle dlrrerence that the ~low control 9 agent, poly (2-e~hylh-xyl acrylate), 1~ lncreased rrom 0.42 grams to 1.0 gram~.
11 Example 31 12 The ~rooedure~ Or ~xamplos 1, 14 and 17 are 13 repeated wlth the ~l~glo dlrr-ron¢e that the rlow control 14 aent, poly (2-ethylhexyl acrylat~ lncrea~ed ~rom 0.42 gram~ to 1.5 gram~.
16 Example 32 17 The proc-dure o~ Example 1 19 repeatod wlth the 18 ~lngle dlrrerence that Copolymer I lB rormed rrom the rol-19 lowlng monomer~ a~ rOllOwæ:
Percent ~y Welght Reactant~ r Total ~-actant~
21 gly~idyl metha¢rylate 15 22 hydroxyethyl methacrylate 6 23 ~lnyl chlorlde 22 24 butyl mothaarylato 17 meehyl methaorylat- 4 26 . Exampl- 33 27 The pro~odure Or Example 1 i8 ropeated ~lth the 28 ~lngl- dlrrerenco that Copolymor I i~ rormed rrom the rollowing 29 monomers a~ rollowæ:

105~931 Pereent Ey Wel~ht 1 Reactants 0~ Total Reactant~
2 glyeldyl mcthacrylate 20 3 hydroxyethyl methaerylate 2 4 l~obutyl acrylate 25 alpha methyl ~tyrene 1~
6 methacrylonltrllo 15 7 methyl methacrylate 8 Example 34 9 m e proeedure o~ E~ample 1 1~ repeated wlth the slngle dl~rerenae that Copolymer I 1~ ~ormed rrom the rol-11 lowing monomers a~ ~ollows:
.Percent ~y Welght 12 Reaetant~ or Total Reaet-nts 13 glyoldyl methaerylate 12 14 hydroxyethyl methaerylate 3 2-ethylhe~yl acrylate 10 16 aerylonltrlle 25 17 methyl methacrylate 50 18 Example 35 19 The procodure o~ E%ample 1 1~ repeated wlth the ~lngle di~rerenae that Copolymer I 1~ rormed rrom the rol-21 lowlng monomers a~ rollows:
Peraent By Welght 22 Roaotant~ or Total Reactants -23 glyeldyl methaerylate 10 24 hydroxyethyl methaarylate 10 ~lnyl toluene 5 26 butyl methaerylate 35 27 methyl methaerylate 40 28 Many modirieatlons Or this lnventlon wlll be 29 apparent tc tho~e ~kllled ln tho art ln ~lew Or thl~ spe¢lrlea-tlon. It 1~ lntendod that all sueh modlrlcatlon~ whlch rall 31 wlthln the ~eope Or thi~ lnventlon be lncluded wlthin the 32 appended elalms.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A powder coating composition which exclusive of pigments and other non-reactive components comprises a coreactive mixture of:
(A) a copolymer of about 5 to about 20 weight percent of a glycidyl ester of a monoethylenically unsaturated acid, 0 to about 10 weight percent of monoethylenically unsat-urated monomers selected from the group consisting of C5-C7 monohydroxy acrylates or methacrylates, acrylamide and methacrylamide, and about 70 to about 95 weight percent of monoethylenically unsaturated monomers consisting essentially of monofunctional monomers selected from the group consisting of esters of a C1-C8 monohydric alcohol and acrylic acid, esters of a C1-C8 monohydric alcohol and methacrylic acid and C8-C12 vinyl hydrocarbons, said copolymer having a glass transition temperature in the range of about 40°C. to about 90°C. and a molecular weight (?n) in the range of 1500 to 15,000, (B) a C4-C20 saturated, straight chain, aliphatic dicarboxylic acid present in an amount sufficient to provide about 0.1 to about 0.6 carboxyl group per functional group on said copolymer, and (C) a polyanhydride having molecular weight in the range of about 1000 to about 5000 and present in an amount sufficient to provide about 0.2 to about 1.1 anhydride groups per functional group on said copolymer.

2. A coating composition in accordance with claim 1 wherein said dicarboxylic acid is present in an amount suffi-cient to provide about 0.4 to about 0.6 carboxyl group per functional group on said copolymer.

A coating composition in accordance with Claim 1 wherein said dicarboxylic acid is present in an amount suf-ficient to provide about 0.2 to about 0.5 anhydride group per functional group on said copolymer.

A coating composition in accordance with Claim 1 wherein said polyanhydride has molecular weight in the range of about 1000 to about 2500.

A coating composition in accordance with Claim 1 wherein said copolymer has molecular weight (?n) in the range of about 2500 to about 6000.

A coating composition in accordance with Claim 1 wherein said other monoethylenically unsaturated monomers consist essentially of esters of acrylic or methacrylic acid.

A powder coating composition which exclusive of pigments and other non-reactive components comprises a co-reactive mixture of:
(A) a copolymer of about 5 to about 20 weight percent of a glycidyl ester of monoethylenically unsaturated acid and about 80 to about 95 weight percent of monoethyleni-cally unsaturated monomers which lose their sole functionality in polymerization, having a glass transition temperature in the range of about 40°C. to about 90°C. and a molecular weight (?n) in the range of about 1500 to about 15000, and (B) a C5 - C13 dicarboxylic acid in an amount sufficient to provide about 0.1 to about 0.6 carboxyl group per epoxy group on said copolymer, and (C) a polyanhydride having molecular weight in the range of about 1000 to about 5000 and being present in an amount sufficient to provide about 0.2 to about 1.1 an-hydride groups per epoxy group on said copolymer.

A powder coating composition which exclusive of pigments and other non-reactive components comprises a co-reactive mixture of:
(A) a copolymer of about 5 to about 20 weight percent of a glycidyl ester of a monoethylenically un-saturated acid, about 2 to about 10 weight percent of an alpha-beta olefinically unsaturated amide selected from acrylamide and methacrylamide, and about 70 to about 93 weight percent of monoethylenically unsaturated monomers which lose their sole functionality in polymerization, having a glass transition temperature in the range of about 40°C.
to about 90°C. and a molecular weight (?n) in the range of about 1500 to about 15000, and (B) a C5 - C13 dicarboxylic acid in an amount sufficient to provide about 0.1 to about 0.6 carboxyl group per functional group on said copolymer, said functional group being selected from epoxy groups and amide groups, and (C) a polyanhydride having molecular weight in the range of about 1000 to about 5000 and being present in an amount sufficient to provide about 0.2 to about 1.1 an-hydride groups per functional group on said copolymer, said functional group being selected from epoxy groups and amide groups.

A powder coating composition which exclusive of pigments and other non-reactive components comprises a co-reactive mixture of:

(A) a copolymer of about 5 to about 20 weight percent of a glycidyl ester of a monoethylenically un-saturated acid, about 2 to about 10 weight percent of a C5 - C7 monohydroxy acrylate or monohydroxy methacrylate and about 70 to about 93 weight percent of monoethylenically unsaturated monomers which lose their sole functionality in polymerization, having a glass transition temperature in the range of about 40°C. to about 90°C. and a molecular weight (?n) in the range of about 1500 to about 15000, and (B) a C5 - C13 dicarboxylic acid in an amount sufficient to provide about 0.1 to about 0.6 carboxyl group per functional group on said copolymer, said functional group being selected from epoxy groups and hydroxy groups, and (C) a polyanhydride having molecular weight in the range of about 1000 to about 5000 and being present in an amount sufficient to provide about 0.2 to about 1.1 anhydride groups per functional group on said copolymer, said functional group being selected from epoxy groups and hydroxy groups.

10. A thermosetting acrylic powder coating composition which comprises (a) an acrylic resin having glycidyl groups in the molecules, a glass transition temperature of 40° to 90°C and a molecular weight (?n) in the range of 1500 to 15,000, (b) a saturated, straight chain, aliphatic dicar-boxylic acid containing 4 to 20 carbon atoms per molecule in the amount of about 0.1 to about 0.6 carboxyl groups per functional group on said copolymer, and (c) a polyan-hydride in an amount sufficient to provide about 0.5 to about 1.1 anhydride groups per functional group on said copolymer, said acrylic resin being a copolymer of 1) about 70 to about 93 weight percent of an alkyl ester of acrylic or methacrylic acid in which the alkyl group contains from 1 to 8 carbon atoms or a mixture of said alkyl ester and other vinyl monomers wherein said alkyl ester constitutes more than 50% of the copolymer, 2) about 2 to about 10 weight percent of at least one hydroxyalkyl ester of acrylic or methacrylic acid wherein the alkyl group contains from 2 to 4 carbon atoms, and 3) about 5 to about 20 weight percent of at least one of glycidyl acrylate and glycidyl methacrylate.

11. The composition of claim 10 wherein said acrylic resin has a glass transition temperature of 50° to 80°C.

12. The composition of claim 10 wherein about 8 to about 15 percent by weight of said glycidyl esters are present in said resin.

13. The composition of claim 10 wherein said vinyl monomer is one member selected from styrene, acrylonitrile, vinyl acetate and vinyl toluene.

14. The composition of claim 10 wherein said dicarboxylic acid is selected from adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and brassylic acid.

15. The composition of claim 10 wherein said poly-anhydride is selected from poly(azelaic anhydride) and poly (sebacic anhydride).