[1]@@59 Patented Apr. 22, 11952 31787 126@@Claims. The present invention relates to,@st6,bilization of polymerizable unsaturated alkyd resins, @,-especially materials which are polymeriz e-;by addition reaction of double bonds in,a gtrutture of the partial forinula involvin-g carbon-axygen zonjugationi@and -.,Ithas partic.ular,relation@- to. such iiiatetials -.when -,they include,.' @lcompound nvolving@ chainlike,@pol .a ,i ;.a@: 7- ester structure.such -as is,.obtained@.bsr condensing an a p iethy.@lenic-a p:dicarboxylic@.,acid with,a,.,dihydric @e@lcahol. whi(yh @is stabilized @against premature,-gelation during.relativ6ly,proloii,- ged@,periods:-o,f.,,sWrage. -A.-second @objwt@ is@:tD.,,prcivide-@a-.material ,which is stable during extended - periods;,of @,,,storage -but which can -readily @4e cured-.to..a,@resinous state 20 .under ap'propl@iate conditions. .A third:6bJect is@to provide a-st@;bilized,-composition of 'the.-@-foregoing @ty-ge @@@whidii,,is -,hidhly resista,nt -to:@gelation n:the,'abgome-of-@peroxide cgto@iyst,s I of P(jlymerizt@tion -but-.- *Wdh -resinifles; 25 quickly b;tz@telAtiv&ly;-Io-w temperatures@;.W-.hen.@a ca;tE@ly8Vis added. A fourth object is to provide a copolymeriz6blLmixture @ of an ethylenically unsaturated mon-UN,ITED STATES @,,@T"T 2,593,787 STABILIZAT]ION OF POLYMERIZABLE -.V.N@SATUP.ATEii @I)tCARBOXY-L-IC @@ACID@' TOL-YESTERS - ,AND@,MIXTURES..TtlEREOF@?@WITH @@V-IN-Yt'fC'MON,O'MERS Earl E.-Parker,..Milw"kee, Wis.,:-4@gignor to-Pitts'burih@'P,I,ite'dlass'Compa4y,@Alieiiitiiy-.td@tit Y, Pa., a corporittion -6f Peni@iilvai@im No'Drawing.,,Applicatio;itMarch-30,1951, Serial No. 21$,'534 (Cl.:260--45@@4.) which the carboxylic @.groups.:.tir-e--!I,irik6d-'to l(ine or both of:,,tlie,@,ethyleriie.@car.,bon@itoins.-.,were cati L -bepa@ble of,,PolymeriZatipn.i@y..44dltipn:@04c,or @ twepn the 60i@14(@ii6 @g:rol @ps df .",a ",P., liii@Olity of "5 @wlectiles'to"for m,@Uieizri6@6tirodutts. 'Th"iiit3i@e of.@- i@igteritil..,is,.Widely, dis@los3'd - 5;pr. ,'pg-,41qple 'in 4t Nos.-' @409-,6a@ L64@@'P @2,"4 52- - - g'r'a-'nted- to - 'kiirdis. 10 I It has - also'been'su@gesteil @D @ii@40 Pr at least fusible linear polyiesters-.@udh-Ei@@@gt6-di@closed .in @@ the 5 -fore goingil..va;terits,@-..wi , tli,-,@@ethylien,ically unsaturated monomers and cgpolymerize One object of the invention,,is@,to the -two -by heati,ng..,the m:ixture., in,.th6,,presence polymerizable @ materisl of @ the @,foregoing @, type r3 6f - @,.i@@r6kd'e,cata;lyst. ' i n i ) igtr,7.., -'Deper.Kiber -'f93'9,,, @pa 19'4@o, page',64. The foregoing poiymerizabl e colli oris P ( s i t i undergo addition reattion, -that is reaetion at the points of carbon-caxbon unsaturgtioii,@;6Ven in the absence of polymerization room temperature or thereabGUtS. pecially true in the case of copo lym6rizo@bl-e-AiAxtu res of the polyesters and the, Ed vi ri@lically unsaturated mongmers of maleic or fumaric acid@,and,@la;" omer and a polyester of a I dihydric...alc4Dhpl apd 30- propylene glycgl or diethylene gly a dicarboxylic acid at least a part.@o I f ,wh I ich@lis ence of a vinylic monomer such as. a p ethylenic, a p dicarboxylic, whi inhibited,,@will @begin t4D,,,gel,almost,..at onee. @h,,m@xture is sta.ble agiiinst gelation under egndiaons,of -,stori@ @ti@i6.-e@en in, the' age and r6adily curable to a resinous@,stgte@tinder c at6,137t-i@.'and@.-at ro ni pi:,be -de@i-r-able.-to,,obtain-.ro apprgpriate conditions. 35 ,m A flfth 'object is to- -provide -a,topolymerimble iit.ni)n mixture of -the foregoiilg type @which@@pures rapidly and @smooth.ly without excessi.ve @ risp- Gf ter@ipemture A,; ixth dbjp6t,-islto provide-- stiehcopoly.Mor- 40,:OPemtiPns. izable:mixtures.'v@hfdh "will 'cure @'rel@@i ]'Phis ,,strong,@ten4oney,,-ot ,fh .,r6latively: large 'coc@tln tdh -are -sojind y@:r vide Iv-was@e'at'.1'. ;'e:'c"o'gi z' 'e-d gs @v@h ure a,nd'of good color. (see., Ilis,.Patent@2i25 313). ..Iil.@,the. E p@@t -'These@,gnd oth-er-objects-wi-ll"b,e .a;pp,'a@r6nt@frlom PrGPOSed to consideration 'of -.the-following 'speelflcatdn -giid 4-5- tion a cellulose ai hile@. the'appended-claims. It has heretofor&,,been,-reepgr4ized:'thmt -linear poly@-sters,-of,-dihydric@-- 6,lcoh-dlg"=d dicg;rl)oxyl@c -iidids, at least &,-pt@iti6n -of @@th -wer6l'a o'f c@ourse'. g;*@',tl-y restricts the fi d, of 4ppjiq4ign of 44p mixtures. It has further been propopi@d,,@c),impiroy4p, t]4e storage 'Chsiadterigties @-6f'@the 'I - ii 'b - , c g p o y 4 i e , , X g L l e I t m o u n t a : o f i i @ @ i i t z e r s miktures by'adding stnt@ I'@t e'thylenically 'Unsaturoted, 'di@64fbGXYIIc -aerds'in@150 such as phenolic c g., @ hy -d"r, -o,q, ' 'u I' -n o-n -6.
[2]2,598,787 U. S. Patent 2,409,633 contains such suggestion. Table B I-Iowever, for many applications, the phenolic 1. Ethylene glycol compounds were poor inhibitors of gelation. 2. Dietl-iylene glycol They often continued to inhibit the polymeriza- 3. 'Iriethylene glycol tion even when the catalyst was added and the 5 4. Polyethylene glycol mixture was heated. Therefore, they unduly 5. 1,3 dipropanediol slowed up the rewtion and necessitated unduly 6. 112 propylene glycol high curing temperatures. This was objection- 7. Dipropideneglycol or di-1,3 propanediol able in making -castings. The inhibitors al o 8. Butylene- glycol, tended to@ disc6lor the resins, a, featuri3 higmy lo objectionabi6 in the caseing art. Castings of sub- Halogen@substitute'd glycols, e. g., monochlor destantial size also tended strongly to crack or rivatives are contemplated. break in the ouring operations. THE SATURATED DICARBOXYLIG ACIDS The present invention is designed to provide w resiniflable composition that eomprises@ an unsat- 5 It i@ to be understood that the inventioii conurated alkyd polyester, a component of v@hich i:@- templates th6 ]@resence of a non-ethylenic dian a e ethylenically unsaturated dicarboxylic - carboxylic acid cornponent along with the eth leny acid (or a mixture of such polyester and a vinylic ically unsaturated dicarboxylic acid in the'@l I polymonomer), which is highly stable lii storage, but ester composit@l-on'. Indeed, in most instances the which will cure readily without substantial dis- 20 mixed pplyesters are preferred. coloration or cracking. Examples of appropriate saturated dicarboxylic The invention is based upon the discovery thet acids are tabulated as follows: salts of quatemary animonium hydroxides are -, Table C outstandingly successful as gelation inhibitors - 1. Phthalic acid during storage, of the foregoing p(>Iyesters or 25 2. Tetrachlorophthalic acid mixtures of such polyesters. 3. Suceinic acid 4. Adipic acid THE PoLymERtzA:BLE MIXTURES 5. Suberic acid 'ihe pol@@eMzabl6 mixtur(@s to be stabilized un- 6. Azelaic acid de@.. the'@ro@isions of the present invention are.. 3( 7. Sebacie ac'id no*, conventional in.the art. The foregoing pAteiits. and aiticles in Ii-idi@strial and Engineering (i@em'isti@y. ird iuii@ trative of the fact. These l@rior a@t r @eferences i@re herewith incorpo@ated as a part of this.diselo-su@e. The mixtuiffes should contain Viit litti@'6r;'i-lo wator. -THE':ETnYLENicALLY UNsATuRATED DicARBoxyLic ACID li i@ apparent that an appropriate a p ethylenic dib@sic a@cid for use in the p@eparation of an 6thylenically - uns@Lturated polyester may comprise a rge cl@ss. some of them in which the carboxyl groplis th@@reof o@re linked to one or both of the carbon gtoms of the ethylenic group designated[, E@@,@on@pqii.exit A are tabulated as follows: Table A l@. Maleic acid 2,.,.,F=oiric acid 3@ ,.@Acoxlitic jacid 4.@,Mes,ac@onic acid 5i@@Citraconic acid 6@. Tt4y.1 maleic @acid 7-.:.Pyroc'mehoilinic acid g.,, Xeronic acid 9,@.,@Ttaconic acid C@@ibic 'acid @-endom6thylene A 4 tetrahydrophth:ilic acid,o'f iny @rior application Serial No. 51@g@639,'filed iiiii6- 9 1945, n'o-w abandoned - of I 1 which this'ap@lication is a co ntinuation-in-part), a,ltholigh not strictlir a bthyl6riic is also cont6m-' lilated.' 9@he@ chi@&@n6 substiiuteci deri@atives ofthe'@acids,"e. 'g."'-'ciiiorom@leic- acid, are also:con.@- I.. @l-! I -; @ . - - . 1. t6iii@lated.- The anhydrides of these acids, where the ah hydriiiels- O'x'ist-;-,ai,r6, of co-urse, erribraced urider the te't'f'n @'Acid-;"-s'lnC6.t.lie re@ei,ion proiduct.s or poly6@ters 'ak6- i@he same. - Often it is p:refdrable t-0 4it)erate *iiii the @nh3@oride rather than the free abid. - - TiiE DinyDRic ALcoHOLS -T-he dihi@d@ic @Llc,6hols te rmed-component (E) of, t@i@ bolyest er- e mbrace such.compounds as are ineluded iifth6 f(ill6wiilg table-.-.-, 8. Dimethyl succinic acid 9. Chlorinated derivatives of the itbove acids :For purposes of the present invention, the aromatic nuclei of such acids as phthalic are re-- 3i garded@ as saturated since the double bonds do not'reactbyadditionasdoethyleniogroups. The term "acid" also contemplates the anhydrides of the acids. YLixtures of any two of the acids 1 to 9: 4t) are contem lated. p Naturally some of the members of Tables A, B and C are preferable to others.. For example, some of them@may presently be unduly expensive,@ but since this condition is often subji@et to change, they are,properly to be included. 45 DRYING OIL AciD COMPONE:NT It may also be desirable to include a small amount of a drying oil acid in the polyester. Such, acids impart air drying characteristics to the polyester, or the mixture of the polyester and the vinyllio monomer. Appropriate drying oil acids termed acid D include those of the follow'mg table: 77able D 55 1. Linolenic acid 2. Linole'c acid 3. Elaeoslt6aric acid 4. Octadecatrienoic acid Clupanod6iiie acid 60, - Mixtures of these acids are contemplated. PRTPARATION'OF THE POf.YE8TEP. in the pteparation of the polyesters, the dih 6.5, 4ricalcohols.of -Table B which preferably.contain.tio.,morb thiln 10 carbon atbms are usually employ6d in ai@Drbximate mol@r- e4uivalency or slightly in excess of such equivalency of the sum of.the.acids.of-TablesACandD. Usually,thig 7,o,. excess will not inuch exceed 10 or 20 Vo and it may, be lower. The excess glycol facilitates reduction. of the -acid number of the poly:ester. The a 9 ethylenically unsaturated dicarboxylic acid ma;y -Constitute the whole of -the acid com@. 7@o. ponent of. the polyester, but, usually it is pre-
[3]terre to include at least some of one or more of the non-ethylenic acids from Table C. The amount iDf acid or ocids from the latter table is capable ;of 'variotioh over a b'road range. e minimilni is,,; course,;none at all,:and the Of M"x'- 5 mum may be 10 iDr @12 m6ls per mole of the acid from Table A. D@dturally, as the - perce'ntage of the acid froin TcLble @'C Is reduced, the Volyester assumes -rilt)re@gnd More closely the chara4bter of the p6lyester eb2itgiiiing orily aoid or a;eids from 10 Table A. It'is imp68sible:to gte@te @an 'Absolute minimum to the; effective amount of adid @from Table 0. Ainoutits at least as low as @3/5 mol per mol -df 'thL, flrst inentioned acid8 Are sug@ gested. 1,5 A comp@onent from Table D is also optional, dependent upon whiather ail, air dt'ying polyester is itegired. A railge 4of 6lie.@@mole of @ Acid D to 2 t-o 12 -niols of @acids A or A ond C @is 8uggested. 20 -Apljroptia;t-e,ra,nges of the several components of the polye8tor hiasr be ta@bui-ated as follows: Componeht (A).@a p ethylenic @a p dicarboxylic acid-2 to 12 @mols 25 Component (C) -Non-ethylenically unsaturalted 'd'fdo,rbt)mylic 6ritioxyal, but if pregent-% to 144 ,ftlols CL)mp6ni5ftt (D@) -t)tyiilg oil ocid, opti6nal'but if hiol Ver'2 tb 12 riiols A+C 30 06mli6nent (13).---@-Dihydric alcohol--- @Equivglent to or In slight excess of A+C-i-@t) CONI)ITIONS OF REACTION -IN PREP-A.RING POLYFSTER In conducting the esterifleation of the dihydric 35 alcohol and the acid or acids, conventional princ@i@l&s,are adhered to. Acid catalysts may be added. The reaction may be conducted under an atmosphere of carbon dioxide or nitrogen gas. X@lene or bther ifon-reactive solvent may be in- 40 cluded -and the reaction may be conducted by heating the mixture to reaction temperature, The quaternary ammoliiun-i salts 'hav6-be6ii@ extensiv6ly d6v&roped as a chemliodl.46!ass. 'Th-ere are many such conipounds availii-ble. -I-rowever, dll hetein coritem@lated will eomprise 'the @f'dllowing basic structure: R2 RI where Ri, R2, R3,,and R4 @are organic @radicals andxisanacid,radical. The saltsmaybe-considered as the reaction,products,of.a quaternary ammonium:hydroxide of the formiila: :R2 Ri lx__@ OH P.3 and.an acid of :the fortnula H-X iwhere @X@-is the 'negative radica@l of the @acid. In the formulae the organic groups Ri.: M. R3, R4 may be -of a, single kind ior @they may @-te mixed. 'All of 'thern may @be @,hydrocarbon @sitch as alkyl, alkenyl:or.alkynyll e. g. ethyl,.methyl, propyl, isopropyl, n-butyl,@@secondar7 butyl,:tertiarsr butyl, viiiyl, methdllyl, or ithey:may @,be @oleyl. orstearyl. All6ra.lYartmaybe"arylle.@gphenyl, benzyl. It is further to ibe @recognized @thELt in some:instances,, 9,:group suchas I?A,,may be:@an organic acid residue, such. as @one -of -the @foxmula where R is hydrocarbon of 1 to 18 carbonatoms and may be alkyl, a-ralkyl -or aryl, e. g., lauryl, oleyl, phenyl, benzyl -or,the like. Some of the Possibilities for the several @'groups Ri, R2, R3, R4 are tabulated as follows: Table E e..g, tb iheit atv@hich water is expelled from the RI R2 R3 R4 system. , it is continued until water ceases to 1. Methyl ---- Methyl -------- in[ethyl -------- - Methyl. evdlve and the acid value of a sample -is reason- 45 2. Ethyl ----------- Ethyl --------- Ethyl --------- - Eth@l, ably'low, e. g., 5 to 50. It should not be continued 3 . Propyl ---------- Propyl -------- Propyl -------- - Prop@l., 4 Isopropyl ------- Isopropyl ----- Isopropyl ----- Isopropyl. so long as to result in infusibility of the poly5: n-butyl ---- ----- n-butyl ---- --- ri-butyl . ---- -- n-butil. ec. bu@ @ See@,butyl. est6r. Usually a teinperatute 6f 150 to 190 or 6. See. butyl ------- See. butyl--- - @ YI .. 7. Tert. b u t y l - - - - - T e r t . b u t y i - - T e l t . b l l t y l . . . T e r t . , b u - t y l . 2000 C. and a reaction tinie of 2 to 20 hours is 8. Amyl ----------- Amvl ---------- Amyl --------- Amyl. sufflcient to effect the'esterification. 9 Octyl-- @ -------- Oetyl --------- Oetyl -------- @ 'Oetyl.. 50 10: Phenyl --------- Phenyl- --- Phenyl --- ---- Phenyl.. If desired, monohydric alcohol and/or mono- 11. Tolyl ----------- Tolyl ---------- Tolyl --------- Tblkl. b6s4id -moy be added to the reaction product o 12.,,Benzyl --- ----- , Benzyl.,-,--- -Benzy] ------- - - Benzyl, f 1 3 .... Cetyl. -------- - cetyl -- - ----- Cetyl. dibasic acid and -dihydric alcoh6l after su6h reac@Oetad eeyl. ( C H 2 ) . - R 2 Where n7is@.a@w ho'le number, - e.;;g.,@2 or--- 3@and'Ri R2; gnd X;ere;a;s,itb ove @defined" @and - @lso @b@ll@i@ lo-Og the $Alt ,not -dOconVo@sed. 76 in this class. tioti is sub@tontially cbmplete. Thereafter the rrii-XtUre iiiay be heated to caus'e f tirther reaction 55 ahd - iirireadted compononts finally distilled 6ff . Usiib,lly, -the unsaturated polyester is very V18dou8 or even,s6lid, but is soltible in the vinylic6My unsaturated inonomer, at least where WAr- med. 60 ST-,@BILIZING TIIF POLYESq@iR COMPOSITIOIZ It @is @ usually desitable'to add the @sa;lt of @a quaternary gftiinonium -to the. polyester in the the:poly4@ster to be stabilited or the mixtu-te thereof @,;ith villylic monomer. To this end ' the quaternary Ekmmonium salt is conveniently added to the polyester while it is warm. It will then dissblve iihmediately and will arrest any tendency 70: of the batch to gel as it cools down. An appropri,E@te temperatilre@at which to make the additidn@iof the:salt is about 1501 C@ though, 6f course, it @-could be it .-c6uld..@ BIso be hi@her siD aWeWe. of in6ii6mer -xegardless of 'Whether,it is 05@rin-g,structure. -Thfsts'yepre sented'by'the-p@tid14: 'oo@ty'dWi Obtadebyl-.- Octadecyl 15.. Alkyloi a@y,,-:-- @ kyyll @r-aryl:: @Alkyl or.aiil::, LaurQyl 16. Allryl oi - Alkyl,or aryl-- I' P.1mito-yl@ a Al 9,T 17. Alkyl or. aryl---- Alkyl or ar Alkyl@or%apyl.- ,Benzy]. I - I It is to be'understood thatthe @vario-us@possible combinations of the 'groiips @ 1 -through 16 'in !.the several.positions Ri, R2, @R3, R4 I aTe contemi5lated@ That is, the cornpounds @ may be, h6mogentous. or so mixed'as,to include -any 'combination -'of -the alyove @groiips 'desired. I In soine instonees, it -will--be, apparent that two 6f 'the groups:Rlare Joined or@iriterconnected'in a inilim@salts. Sdlts-of,the,.formula: RI
[4]7@ It is further to be appreciated that a. plurality of, quaternary ammonium groups may share. a dommon hydrocarbon radical. Such ccimpounds is represented by ethylene bis(pyridinium chlotide) and ethylene bis(trimethyl ammonium bromide). Ethylene, Dropylene, butylene and higher alkylene or ethylenically unsaturated hydrocarbon groups are also contemplated in one or more of positions R2, Ri, R3, R4. The presence of non-functioning substituents such as one or more chlorine or bromine atoms in the hydrocarbon radicals is not precluded. In the acid component of the salt, whose n6gative radical is represented by the group X, the latter group should be at least as strongly negative as acetic acid and should not involve heavy radicals or groups that would reduce its negative cha'racter I or unduly impair its mobility in the mixture. The use of excessively heavy organic acids to form the salts may also unduly increase the amount of salt required to attain stability. Organic acids employed preferably are of a weight not much above 200. Salts of weak acids, of course, are of basic character, owing to the strong basicity of the quaternary ammonium hydroxide from which the salts are derived. Basesi usually, promote gelation rather than iiihibiting it. The salts of the strong non-oxidiging mineral acids usually are the most satisfactory. The acid organic substitution products such as the acid sulfates, sulfonates and phosphonates of these acids are also contemplated. The following are some of the acids that may be employed to supply the radical X: Table F 1. Acetic 2. Suceinic 3. Sulfuric 4. Phosphoric 5. Hydrochloric 6. Hy&obromic 7. Chloroacetic 8. Malonic 9. Hydriodic 10. Oxalic Hy&o@y acids such as: 11. Malic acid 12. Tiirtaric acid 13. Lbctie acid it is de@sirable that the quaternary ammonium salt @be. soluble in, or compatible with, the polyester or mixtures of polyester and monomer at least in amount to attain desired stability. The invention contemplates the use- of the various quaternary ammonium compounds which are presently enjoying use as germicides and surface tension reducing agents. Quate.rnary ammonium salts of more strongly oxidizing acids, such as nitric acid, chromic acid and the like, are less desirable inasmuch as they may strongly, influence the gelling characteristic.s of the mixture by their oxidizing effects. Sul-. furic acid or phospboric acid are not of this type. Hence salts of acids which have an oxidizing power no greater than that of phosphoric or sulfuric are within the contemplation of this invention. The following constitute specific examples of quatemary ammonium salts which are contemplated as stabilizers or gelation inhibitors for polymeriiable polyesters or rnixtures of such Pglyesters and ethylenically unsaturated monomers: Table G 1. Trimethyl benzyl animonium acetat6 2. Trimethyl benzyl ammonium chloride 3. Trimethyl benzyl ammonium broniide 4. Triethyl benzyl ammonium chloride 5. Tripropyl benzyl ammoniuni chloride 6. Tributyl benzyl ammonium chloride 7. Cetyl trimethyl ammonium chloride .10 8. Octadecyl trimethyl ammonium chloride 9. Trimethyl benzyl ammonium sulfate 10. Lauroyl pyridinium chloride 11. Phenyl trimethyl ammonium chloride 12. Tolyl trimethyl ammonium chloride 15 13. Benzyl trimethyl ammonium phosphate 14. Benzyl trimethyl ammonium iodide 15. Ethyl pyridinium chloride 16. Phenyl tr@giethyl ammonium chloride 17. octyl trimethyl ammonium bron-dde 20 18. Ethylene bis (pyridinium chloride) 19. Ethylene bis (trimethyl annnonium bromide) 20. Trimethyl benzyl ammonium oxalate 21. Trimethyl benzyl ammonium malate 22. Trimethyl benzyl ammonium tartrate 25 23. Trimethyl benzyl ammonium lactate One important group of quaternary salts comprises those with a benzyl group and three alkyl groups, (methyl, ethyl, Propyl, butyl, amyl or the like) directly attached to ammonium 30 nitrogen. These compounds may be represented by theformula: alkyl / alkyl benzyl-N 35 alkyl \ x X being an acid radical of an acid as strong as acetic acid (dissocation constant 1.75xlO-5 or stronger. Another important class comprises quaternary 40 ammonium salts where one hydrocarbon group is higher alkyl and contains at least 8 and up to 18 carbon atoms; three hydiocarbon groups are lower alkyl containing up to 6 carbon atoms (methyl, ethyl, Propyl, butyl, hexyl). The struc45 ture of such compound may be represenied by the formula - lower alkyl lower alkyl higher alkyl-N / \ 50 lower alkyl x X again being an acid or negative group of an. acid at least as strong as acetic acid.@ Salts of quaternary ammonium hydroxide can, be dissolved in polyesters of a a ethylenic a 6 1 di55 carboxylic acids and dihydric alcohols (or their derivatives as modified by dicarboxylic acids and/or drying oil acids) to provide products thet can be stored for very long periods without fear of gelation. The stabilizers are preferably adcled 60 to the Polyester while the latter is hot. A curing catalyst, e. g., benzoyl peroxide, tertiary butyl hydroperoxide, cyclohexyl hydroperoxide, acetyl peroxide, lauroyl i)eroxide, or the like ca;n be added to the stabilized mixture 65 in appropriate amotint (.01 to 5% by weight) at any time. The mixtur6 when heated will' cure rapidly and completely with but little Interference from the inhibitor. 70 COPOLY@AIERIZABLE MIXTURFS OF POTYESTERS ANF) VIINYLIC MONOMERS The copolymerizable mixtures of the polyesters and vinylic monomers are, of@ course, much i more reactiye than, the Polyesters per se, and To the stvil>ilization@ of these Mixtures @ is usu%lly-
[5]lo; mq;@e-. ikr th A thp@t,. Qf. thq: pqlyester. qh tbpy. 4boqlcl bo, @iiie@pi y wa m to m x Wtth @@06 e4@l c,pl?olyr4er,lzo@ble mixtu@Te May comprise any of and dissolve in the -monomer tq: o r V i A y l i p p 6 l l y U 4 7 tbg@ p6i@e@teis: wjiieh have alrqady been degeribed .5 aturated c(mppukid- Thi@. 4ternar aznmoqi; y and t@-6s'e@ may b-e incorporated with a suitable ni um sglts Eks herqiiq Oisclosecl, stabili I zq. thp covinylically unsaturated, mo4omer such as those 5 p olyrgeriz4ble lpixtures while the ethylenically referrea to in the foregoing patents. unsatur@t d o .1 r vin ic y,, up@@tilrated compoiind p y 1 411 is, in Vvh tlip, inixture is THE. VINYLIC MONOMEBS - .-.-cQrpor4tp-d. therqin, exi cooled (iown to Irpom temperatuirp, it vvill remAi4 'rho monQxnor.5 com prise@, axly of. th I P comr4on stabl el. for 9 e vinylic, com ounds@ cadable of cross linking un10 r4i , c nsiderable i.jeriod , To diir the I p xture, catalyst i 40ded an t]4e hlixture is saturated i)olyester molqcules at, their point$ of I 4, rai sed to curing tqmperature. Th salt do not e , p@ un tu at n. Usually they eqntain the react subst,@t4tially 1 er e e with the, desiied clire. sa r io nt f r group ]iT2C=C<. The eth e i all The m@xtu es usugll,,y a e free of p6ter Qr zle@ar-ly y unsaturated w p o l y e s t e r @ a n d t h e v i n y l i c a l l y u n s a t u r a t e d c o m - S ( ? . p o u n d s a r e m u t u a l l y s o l u b l b . T h e m o n o m e r i c 1 5 W l i a r e @ u l t g 4 t r 4 i x u e . g s t a l e i i i s t o r a g e - t ,r 4 rk,- b.- - . ., @7 compound@is PIso normally a liquid, polymerizfQr ipp67. ppi@iods of time in @ome. cases for a able. compound. $ome of the monomf,,rs-a-re pQriQd, Qf at Ipp,;@t tbrpe yoa@4, wh !ph i.s ofte@4 tabulati@(i as fQ!Iowsbpttey ptg@ility , Pve ;4 tbg4 is requi@qo. Table H ,qwever wlien the: mi: tur s, are t bi? qu 0 ' . pqd 1. :@tyrene @o they,q4il easily be incorpp@4ted with a ppirg@040 2. a methyl styrene qatqlyst,, sucb , as benz YI p@eroxide or tertiarv b u t y - I h y d r o p e r e x @ c i p o r , o t h e r s i n c o n v e n t i o n a l 3. p methyl styiren.e 4, Divinyl benzene RmQV4t@, e. g., .1 to 5%, apci cured. The tem5. ipdene p er-atu@p of cure cai4 be moderate, e. g., below UnsatiArated esters s'uch as: 25 1001 C., bu@ may be much lower, e. g., room tem6. Vinyl acetate pe@4ture (221 C.,) pr thereabouts. The@ ;re@Ains 7. Uetbyl methacryl4te r4gy be fu,rther harde d- by baiipg- thern, t 4e 8. Methyl acrylate 125 to 1500 C. or therepb@ut@. I-Iigher tempera9. Allyl acetate tures of initial curing and baking are permissible. 10., Diall phthalatp 30 However ti@e-y should@ not be so high as to volatilYi I 11. I@ioilyl sucei ate ize t-he mon6mer (in initial @cure) or to char or 12. Di@@llyl@ adipate discolor the flnal product. The time of curing 13. Z)iallyl@ sebacate and baking, of course, will va gre tly depending I @ - y a 14. @-p6 -' @u@h f-actor-'s as the si2e and thickness of Diet-hylene glycol bis (allyl earbonate) n @ 1 15. TrioA, lyl p@io@phate 35 the body to be formed and the temperature of 16. Vin reaction. Usually 5 minut s to 2 hours@ are suf T YI chloride e. fleient. However, it is easy to determine by A.iiy one of these vinylic monor-qers, May be hardness tests when the ar-ticles are cured to combined with an of the polyesters prepared .y hard,.,clear state. from components A and B, A, B and C, A B and 40 it is@ an impgrta t feature of the us of the T> or A, B" q and D as previously described. quaternary ammonium salts as inhibitors of Mixtures of any two or MQTE of the foregoing ge @lation that alth6ugh the are very effective in vinylic compounds and the polyesters are conpe riods of sto@age of the uncatalyzed mixture, templated. the catalyzed mixtures cure very readily@'and The vin,ylic monomer usually will comprise mp letely at low temperatures. Where the mL@- 4ro CO frqm, IQ to 60% upon a weight basis of the rQ@ t ure is employed to embed delicate objects such polymeri,zable rnix re, and mix tures coiltaining tu as insects bi6logical specimens or the like, cure 20, to 40 or 50 % by weight of monomer are to be ca n be effected without damagin them Al , g s o , i n preferred,., making cast@ngs in molds 6f latex or the lijce, To formulate stabilized or non-gelling.Mixtur QS 50 the' low curing tepiperature is desirable to avoid e use of tb I e quaternary ammonium salts that they do notdiscolor (11)@:a vin.@l,ic monorqer, it @s pref rred the product in which they are employed. Pur.gol,ve A cluaternar a moniu4i salt (for e 55 ther more, castings formed from copolymeriz.Y m one of those listed in Table G) as an i able MiNtiirp4 gr.@ @oi4p4 Apq free of cracks. Prodin thi@ polyester component. This is best accom- ucts in iwhich conventional inhibitors are emplished by a@dding the salt to the polyester while ployed du rin ptqr4gp pfte4 4re, crack d gr I ..g. - e . the latter @ is hot, e. 9.1 about 1500 C. or to such broken. This is esppcially true in the case of Gther temperature as will effect rapid and com60 i@ealtivel y r4;@kssiv e casting4.. plete solution. This can @be determined by obIt is to be u4d(@rqtppd that while the ciuaternary servation, as it@is easy to see when all of the amm_onium salts,:t k n by til@Mpo@vi@s, pre -ex . I @ g e quaterna@i@@ @alt ha8 disappeared into the polycellent gelation inhibitors for. cop glypp@14p@blp ester. The@quatp-rnary ammonium salt may be mixtures of unsaturated polyesters and vinylic added in an @mount of about .01 to 2 % by weight 65 T4o nomers. other inl'i'-'t C i bi ors su h as those of of the ultim@ ate mixture of compdnents I and II. coiR ve4@lp4q; @ypp, puph as hydroqp@@one, can Thi@ is essentially the same procedure as is emalso be included,alongwith the salts. These may ployed to;stabilize the polyester without mon@ he employed, for e)@ample, in a R I roportion of orner. q pp ,,r gxi tel 1,@o by weight bosed uppn the The monomer such as one of those from Table 70 W'p @@ght.qf the,.quat6rnar sal or such 6ther pl@gy t H is added. iti@ appyopriate amount at 120, C. or pp:r Vion as is expedi,@rit, 5,uph 4dditional inhibilowor temp,6,ratures (e.. g,, 10 tq 60% by weight of tqr ,p sox4et;iA e@ aTe li e@ bm n , , @ l p f i 4 l w ] 4 e r t q t i q , @ a the monomer'stal@ilized PolYester mixture). te4lporature of the clire is relativelyuri@nlpp@tant Since the ulisaturated polyesters are usually a4d where it. is Opsirable to incrqdse the soquite viscou-5 or even solid at, room temperp,@urip, 75 p a I d Ift li@611, thp mixture,, tha is t' l.e, an t7@ of (I) an unsaturated polyester of a dihyd ric dame@ge to the molds. alcohol ond an acid compris t g an a 6, It is also a fea ure of th bpx- ic a p ethyle n yl nically u saturated aci
[6]2,593,787 crease the period in which catalyzed mixtures can be stored without gelation. It is understood that such vinylic monomers as styrene, as sold commercially, normally contain small- amounts of inhibitors to admit of 5 storage.and shipment thereof without gelation or polymerization. Commercial monomers containing such inhibitors, e. g., quinone or hydroquinbne, in small amounts can be employed in the, present process. obviously, the inhibitor in 10 the monomer is greatly diluted when the latter is incorpo,rated with a polyester under the provisions of the present invention. Also, in many instances, the-effectiveness of the added inhibitor carried in- the monomer has been greatly reduced 15 by the period of storage which the monomer has undergone before it is admixed with the polypster. Normally the inhibiting effect of the stabilize,r in the monomer will not be objectionably great. However, if so desired, the in- 20 hibitor of commercial styrene or other monomer can be elhninated by distillation before the monomer,@is incorporated with a polyester containing a q 4a.@emary ammonium salt as an inhibitor. 25 . Applications of the principles of the invention @are, Illustrated by the foll6wing examples-. EXAMPLEI Trimethyl benzyl ammonium chloride, in a proportion of .003 part by weight was incorpo- 30 rated.@into 2 parts by weight of propylene maleate @l@thalate which was a polyester of approximately 1 mol of maleic acid and 1 mol of phthalic acid witl@ 2 mols, or a slight excess thereof of propylene gly , pol. The addition of the salt was 35 effected by adding it to the polyester while the latter was at a temperature of about 1501 C. This mixture was quite stable over long periods,of time. -When it is desired to effect a 40 cure-of the mixture, a catalyst, e. g., benzoyl peroxide, or any of the others herein enumerated, e. g., .1 to 5%. The mixture can be readily polymerized by heating it in the usual manner. Prodiiets resulting from such mixture are hard, ,clear and sound. 45 -'t6 the st ' abilized mixture a monomer such as styrene or any of those from Table R can be added to,provide a stabilized copolymerizable mixture. The mixture cures rapidly when a 56 catalyst such as tertiary butyl hydroperoxide is added. The amount of monomer may be within a riiige of 10 to 50% by weight of the total mixture. EXAMPLEII r) 5 To a mixture of 2 parts by weight of propylene ,maleate phthalate and a quaternary ammonium salt, e. g., .003 part trimethyl benzyl, as above describe-d in Table G, was added 1 part by weight of diethylene glycol bis(allyl carbonate). This inixtu@e was stable for more than 18 day-s at 60 iSO'@l@P. (an accelerated aging test) and for 6 mo-nihs at 701 F. EXAMPLE III In this example, 2 parts by weight of propylene '65 maleate phthalate were stabilized with trimethyl benzyi ammonium chloride as described inconnection with Example I. This mixture constituied a stabilized unsaturated polyester which could.be stored for long beriods of tiine without 70 obj.13ctionable polymerization. To this mixture could be added 1 part by weight of methyl methslerylate as a monomer. Such mixture is stable for more than 40 days at 150' F. and more than 180 days at 700 P. Corresponding mixtures of 75 12 propylene maleate phthalate and methyl methacrylate in the E@bsence of the gelation inhibitor gelled in less than 1 da-y at 1501 P. and within 30 days at 701 P. EXAMPLEIV In this example, 2 parts by weight of propylene maleate phthalate containing 0.003 part by weight of trimethyl benzyl ammonium chloride were incorporated with 1 part by weight of vinyl acetate. The mixture did not gel in 40 days at 150' F. or within 180 days at 700 P. The unstabilized mixtures gelled in 1 day at 150' P. and within 30 days at 70, P. EXAMPLB V In this example, 2 parts by weight of diethylene f umarate were stabilized with .003' 'part by weight of trimethyl benzyl ammonium bromide in the manner already described. This mixture was stable and could be preserved for long periods of time without gelation. It could be cured in conventional manner. Two parts by weight of this mixture were added to 1 part by weight of diethylene glycol bis (allyl carbonate). The mixture was stable for more than 50 days at 150' F. and for more than 180 days at 701 P. A like mixture free of quaternary ammonium salt gelled in 1 day at 1501 P. and in 30 days at 700 P. EXAMPLE VI In this example, 1 part by weight of a polyester which was Propylene maleate was stabilized with 0.002 part by weight of triethyl benzyl ammonium chloride. The polyester could be preserved satisfactorily and would cure in the conventional manner in the presence of suitable peroxide catalysts. To the polyester mikture was added an equal amount by weight of diethylene glycol bis (allyl carbonate). This mixture was stable for more than 50 days at 1500 F. and for more than 180 days at 70' F. A like mixture free of added inhibitor gelled iii a.single day at 150' F. and in 30 days at 70' F. EXAMPLE VII In this example, 2 parts by weight of propylene azelate maleate could be stabilized with .001 to .0 1, e. g., .003 part by weight triethyl benzyl am@ monium chloride to provide Ei stabilized polyester. The stable polyester was then further incorporated with 1 part by weight of diethylene glycol bis (allyl carbonate) to provide a copolymerizable mixture. This mixture was stable for more than 20 days at 150' F. and 180 days at 700 IF. The corresponding mixture without the inhibitor gelled in 1 day at 150' F. and in 30 daysat 70' F. D@ XAMPLE VIII To 1 part by weight of propylene maleate phthalate was added .001 to .01 part of phenyl trimethyl ammonium chloride thereby providing a stabilized propylene maleate phthalate polyester. This mixture was. suitable for use as a polymerizing type of alkyd resin. When a peroxide catalyst was added, it would cure by addition reaction. To the mixture was added an equal amount by weight of diethylene glycol bis (allylearbonate). Themixturesuccessfullywithstood an accelerated gelling test at 150' F. for 20 days. It was stable at a storage temperature of 77, P. for 120 days. - EXAAFPLE IX To 2 parts by weight of diethylene fumarate adipate was added .0015 to .015 part lauroyl pyridinium chloride to provide a stabilized polyester mixture and to the mixture was then added 1
[7]l@3 :part@ by wc@ight of- diethylene glycol bis (all@yl catbonate-) io, form a mixture that:was stable @f-or 20 days at 15'OP F.. and fbr 120@ days a-t 77" F. 2,503@78,7 To a mixture of .003 part by weight of any one :of-. thequaterna-ry ammonium salt& from Table G, e. g.,, triinethyl@ laenzyl ammonium bromide in 2@ parts- by weight of diethylene fumarate was addedl@partbyweightofdiallylphthalate. Such 1:0 rnixtu-re@ was' stable for more than 50. days at 150' F. a@nd 180 days at 701 P. E.C@AAIPLE XI T-o a mixture of 1 part propylene maleate add .002'part by weight of any one of the quatertiary I 1,) :a=ohium salts from Table G, e. g-.1 triethyl henzyl ammonium Ghloride, -and to the resultarit mixture add 1 part by weight diallyl phthalate. The resultant mixture will withstand an accel er.ated gelling- test at 150, F. for 50 days and will 20 withstand- storage at 701 P. for 180 days. FI,XAMPLE @,II In this example, 2 parts by weight of diethylene fumarate phthalate may be stabilized by means , 2,5 of .015 part trimethyl benzyl ammonium acetate and to, the stabilized porlyester may be added 1 parti4y, weigh@t of diailyl phthalate to provide a coporlymerizable mixtur6 stable for 10 days at 150' F. or i2O days at 70' F. When it is - desired ( ta@cur.e the@ mixture, a peroxide type catalyst may be added in appropriate amount, e. g., .1 to 5%, and the@mixture cured in conventional manner. EXAINIPLE XIII In this example, propylene azelate maleate in 3;5 a proportion of 2 parts by weight may be employed, Octadecyltrimethyl ammonium chloride in an amount of .001 to .1, e. g', 0.01 part, parts by weight may be incorporated as a. -stabilizer. One part by weight of diallyl phthalate may be 40 added as a vinylic monomer. This mixture is stable for 40 days at 150' P. and will withstand storage for 180 days at 77, F. E@XAMPLE XIV 45 Propylene adipate fumarate iii a proportion of 2 parts by weight was stabilized with .001 to .01, e. g., 0.003, part by weight oetyltrimethyl ammonium bromide and I pal-t by weight diallyl 180 da-ys at 70' P. EXA.LIIPIF, XV Propylene maleate pbthalate in a proportion of 1 part by weight was stabilized with .001 to .01, 55 e. g., 0.003, part by weight of benzyl trimethyl ammonitim sulfate and to the stabilized polyester was added 1 part by weight of diallyl phthalate to,.form a copolymerizable mixture which would withstand an acceierated gelling test of 150' p. 60 for 15 days and storage at 70' F. f I or 150 days. EXAMPLE XVI Add to 2 parts by weight of diethylene fumarate 0.003 part by weight of any one of the other 6,5 quaternary ammonium salts from Table G, e. g., triinethyl benzyl aminonium bromide. Then add 1 'part by weight of vinyl acetate to the rnixture. This copolymerizable inixture will withstand. the accelerated gelling test at 150, F. for 50 days and 70 will withstand storage at 701 F. for 180 days. .The mixture can readily be incorporated with eatalyst of the peroxide type and successfully c I ured to a hard durable resin in the usual manner. 7 5 14 EXAMPLE- XVII Diethylene maleate phthalate in a proportion of 2 parts by weight was sta-bilized wlih 0.003 part by weight of triethyl benzyl ammonium chloride and to the stabilized polyester was added I part by weight of vinyj acetate to form a mixture that will withstand the accelerated gelling. test at 150' P. for 50 days and which can be stored: at 70 P. for 180 days. EXAMPLE XVIII In this test, a stabilized mixture of 2 parts by weight propylene azelate maleate, 1 part vinyl acetate and .001 to 0.1, e. g., 0 ' 02, part by weight of trimethyl benzyl ammonium acetate was preP I ared. The mixtlire withstood the accelerated gelation test at 150' F. for 10 days and withatood storage without gelation for 120 days at 70' F. The corresponding mixture without stgbili@er gelled in I day at 150' F. and in 25 days at 70" F. EXAMPLE XIX Propylene adipate fumarate in a proportion of 2 parts by weight was stabilized with triethyl benzyl ammonium chloride in a proportion of.001 to .01, e. g., .006, part by weight and then was admixed with I part by weight of vinyl, acetate to provide a mixture stable for 30 days or more at 150' P. -and which could withstand storage for rqore than 180 days at 70' F. The corresponding mixture in the absence of stabilizer gehed at 150' P. within,a day and within 27 days at 70' F. EXAMPLE XX A mixture of 2 parts by weight of diechylene maleate phthalate al-ld I part.by weight of methyl rnethaerylate stabilized with 0.003 part by weight triethyl benzyl ammbnium chloride was stable for 11 days at 1.50 F. and for over 90 da@s at 70' F. E'@KAAIPLE, . XXT Propylene adipate fumarate in a proportion of I part by weigbt and metllyl methaerylate in a pr6portion of 1 part by'weight was stabilized with .001 to 0.1 part by weight of trimethyl benzyl ammonium bromide. This mixture could be stored under atmospheric conditions and when incorPorated with benzoyl perox . ide or tertiary butyl El XAMPLE XXII In this example, a simila'r niixture was prepared from 2 parts by weighi @ of diethylpne maleath Phthalate, I part by wei@ht 6f methyl methaery:late and .001 to (Y.1 part trimethyl ammonium phosphate. EXAMPLE XXIII In this exaniple, 2 parts by weight of propylene maleate phthalate (equal mols of maleic acid and Phthalic acid) were stabilized with trimethyl benzyl ammonium Paratoluene sulfonate. To this inixture was added 1 part by weight of styrene. With a total mixture containing .1% by weight of th-e salt, a stability of 4 days at 150'@ F. was obtai-ned. EXAI%IPLE XXIV .5 parts propyleiie rnalo-,ate phthalate 18 parts styrene 0.1 to .5% inhibitox .001.0/c quinone In the polyester, iiialeic acid and Phthalic. a c i d phthalate was added as a monomer. The result- go . hydroperoxide or other catalyst of polymerization alit mixture was stable for 30 days at 150, F. and could be cured to, a satisfactory resin.
[8]2)598 787 16 were equimolar. I'he inhibitors and the storage pages 704-711, Carleton Ellis, copyrighted 1935, tests are tabulated below: Reinhold Publishing Corporation. Mixtures of the two types of catalyst, e. g., lt7o' of benzoyl Per Storage Life peroxide or tertiary butyl hydroperox w Inhibitor Cent 5 butyraldehyde-aniline may be employed Used In 6rder to promote the polymerizatioil Of a 150, F. 77' F. -- mixture such as is disclosed in Examples I to XXV Cetyl trimethyl amtuonium bro- 0.5 21 days -- -- ine - lusive, a catalyst, e. g., benzoyl peroxide, or mide' any o'L the others mentioned, in an amount of Octadecyltrimet@yl ammojiiuni 0.5 30 days ---- cbloride. 10 .1 to 5,7o by weight is added and the mixture is Bmzyltriinethyl ammonium chlo- 0.1 2(@-40 d,@iys- 1 yr. heated up to an appropriate temperature for ride. Benz Itrimethyl ammonium bro- 0.1 8 dayg ----- (i moittlis. example, to a-bout 93' C. Lower temperai@@es, m ii @(e. say 75' C, may glso be employed. By heating Benzyltrimethyl aminoniuni siil- 0..] 3 days ----- 3 months. fate. the mixtures at this latter temperature for a Beiizyltrimethyl arn-monium ace- 0.1 3 days ----- 45 days. 15 period of about an hour, it can be polymerized tate. .Latiroyl pyridinium c'Ql,)ride 0.1 33 d@iys.--.. to the setting stage. Subsequently, It eaii be Phenyl trimethvl ainrnoiiium 0.1 20 day@,---- ehloride. rendered harder and more durable by baking at BeTizyl trimetbyl ammorijuin 0.1 20 days- a temperature of about 125 to 1501 C. Of course, chloride. higher temperatures of baking can be employed Etbylene bis (pyrodi-nium chlo- I 0.1 14 ride). 20 provided they are not so high as to char or disEtbylene bis (trimethyl ar-qmo- 0.1 10 days ---- color the product. The products normally wiU nium brornide). Control ---------------------- -------- I hour ----- I day. be clear and strong. The polymerizable mixtures may be cast and cured in suitable molds with or in Examples I through IV, VII, VIII and ix, without pressure. XII, X]aI, XIV, XV and XVII through XXIII, 25 Mllers such as cellulose fibers, asbestos and the ethylenically unsaturated and the saturated glass fibers can be added to the stabilized polydicarboxylic ac;@ds are in approximately equal merizable mixtures in amounts, for example, up ',ar ratios. to 300% or more based upon the polymerizable mo, This ratio can be var4ed in the rtianner heretofore described. liquids. Fabrics of glass fibers can aiso be ini@o pregnated or coated with the polymerizable mix@ A trace of quinone, e. g., about 1% based on 3 the tertiary amine or quaternary ammonium salt content of the mixture can be added, further to stabilize the mixtures in the preceding examples but in most cases stability is adequate without it. From the foregoing examples it will be appaxent that polymerizable dihydric alcohol esters of at@ha-,beta unsaturated, alpha-beta dicarboxylic acids, or copolymerizable mixtures thereof with monomeric olefinic compounds capable of effect40 ing cross-linkage of the polyester nuclei can readily be stabilized with salts of quaternary ammonium compounds to provide mixtures that can be stored ivithout geuing for long periods of tixne. 45 It is to be appreciated that in order to eff ect . a.rapid cure of the mixtures of polyester and th6 olefinically unsaturated monomer, a cataiyst of the addition reaction involved in copolymerization is usually desirable. However, in some in-@ r)o stances, e. g., where high curing temperatures or long curing times are permissible, or ultraviolet irradiation is available, catalysts may be omitted. , . Appropriate catalysts include peroxides such r )5 a-s: Benzoyl peroxide Tertiary butyl hydroperoxide Cyclohexyl hydroperoxide 60 Acetyl peroxide Lauroyl peroxide These are merely typical, others are a-vailable. -The catalysts will usually be emplpyed within a range of .01 to 5%, e. g., 1% of the mixture. 65 Preferably the catalyst is added shortly before the mixture is to be polymerized. Other types of catalysts such as thioglycollic acid or catalysts such as are employed as accelerators of rubber vulcanization or as rubber pre7o servatives, obtained by condensation of arnines and aldehydes, e. g., forrnaldehyde or acetaldehyde or butyraldehyde and aniline or toluidine may be employed. Many of these are described , in The Chemistry of Synthetic Resins, vol. I, 75 tures. Mixtures of fibrous material and resin con@@tituents can be heated under pressure to form hard, strong bodies of appropriate form. , PIasticizers such as dimethyl phthaiate can also be added to the polymerizable mixtures in amounts, for example, of 5 to 40% based upon Polymerizable constituents. The Polymerizable'mixtures can be applied as coatings to -metal wobd, paper, cotton or other cloth and cured i@ situ to form protective fllms. EXAMPLF, XXV This example is for purposes of comparing quaternary a-mmoriium salts as inhibitors of gela,tion in polyesters of alpha-beta ethylenic alphabeta dicarboxylic acids and glycols or mixtures of such polyesters and monorners with other common types of inhibitors. In the tests, a polyester wliieh was the condensation product of 2.2 mols of 1,2 propylene glycol, 1 mol of maleic anhydride and I mol of phthalic anhydride was prepared, and was then divided into 4 equal samples of 200 grams each. To sample I was added .1 part by weight of trimethyl benzyl ammonium chloride. Samples II was stabilized with .1% by weight of parabenzyl amino phenol. Sample II:I was stabilized with .1 % by weight of di-beta naphthyl paraphenyl di-amine. Sample IV was stabilized with .0 168 % by weight of hydroquinone. To each of the four samples was added 100 grams of styrene. To th.e foregoing samples was added ..5% by weight of tertiary btity-I hydroperoxide which is the catalyst most,cornmonly used in casting rnixtures of the foregoing tYPe. The samples wer6 then placed in pint jars of comrnon Mason type so. that the depth of tlie copolymerizable mixture in all Jars was about equal a-nd greater than 1 inch. The jars were the-n piaced in a water bath at 100' P. for I hour. At the end of this period, sample i. cont . aini . ng triinethyl benzyl ammonium chloride as a -it@L-bilizer had gelled, indicating that the stabilizer had but little retarding effect uporl the rat,6 of
[9]2@)5931787@ cure of the ca;talyzed mixture at moderate temperat,ures. This stabilizer would be very desir@. able ill rnixtures employed iy-i forming castings Iv,rhere low temperatures of cure@:were required. None of the other sainples had, gelled. This was 5 aln indication that the inhibitors in these samples had materially retardea the rate of cure of tbe mixture at 100o F. The water bath i@ias then gradually warmed over a period of I hour to a temperature of 190' P. 10 at which value it was held for a further p4eriod of 15 r-qinutes. At the conclusioii of this period, it vvas found that al-I sampl6s had resinifled and the products were of the follbwing characteristics, 15 Sample I which was stabilized with trimethyl benzyl ammonium chloride was a hard, sound casting Nirhich -was clear, colorless and free of cracks. Sample II Nvhich had been stabilized with .1 % 20 by weight of parabe,.izyl amino phenol restilted iT,i a, productarhich was brown in color and severely fractured. Sample III which was from the mixture stabilized with d-i-bet,,i naphthyl paraphenyl di2 1-) amine was black in color and was severely fractured. Sample IV which had been stabilized with hydroquinone formed a resin which was of a yellow color. and ivas severely fractured. This 30 test demonstrated the fact that the quatemary ammonium coinpound wp-s of outstanding merit in tlie protection of inixtures employed @aseasting resins, especially those to be cast at low or moderate temperatures and in the absence of sub- 35 stantial pressures because the stabilized mixtures could be cured so re,-dily to provide such satis.factory products. ri,.%'AilIPLE XXVI 40 in tT.L;s example, a series of tests were conducted to determine the stabil,izing effect of a number of difierent quaternary ammonium salts in the absence of cat;ilysts at an eleva,.ted temperature and further to test the @curing rate of these samples after the catalyst had been added-. Por purposes 45 of comparison, sim,:Iar tests were conducted upon sa,-nples stabilized with certain conventional- inhibitor,s of.gelation. In the example, a,polyester 18 weight of styrene. This mixture was divided into thL- requisite number of sainple s for the, severb6l tests. The accelerat@6,d aging test hereinafto-r desig@. iiatod as"Test A" I wa;s conducted by inebrporat@ing the gelation i,.ihibitor to the unca;talyzod co-; polymerizable rnixtur6,and subjecting the; sta@bilized mixttire to a temperature of 150' F. uritil g@blation occurred. The low temperature test, "Test B" Was conducted at sligl-itly abov.e norrqal room temi)6rature W. ,t.li. enzoyl peroxido as a catalyst. The latter was added to Llie stabilized mixtures a2ad the mix@tures' w@ ere stbred at 771 P. Piirther to determine the retarding effect @of the iiihibitors upoh the copolym,-rizable mixture8@ after the @addition bf catolyst ert ary 'It i butyl hydroroxide w@Cs addedto samples stabilized with.1% by @veight of the severbl inhibitors in a pr@oportion of .1 % by weight and the stabilized nuxture was then stoi,,-d at 77' F. iintil gelation ocdurred. This test is hereinaf@@--,r designated as "C." A @similar test was conducted upon certain- of the stabilized mixtures ilicluding thb various gei'.ation inhibito@-s with .5 Yo of tertiary@ @but@l hydrbperoxide as a - catalyst. This test is hereinafter desi,.anated as "D." nnally, to determine the retarding effect of the gelation inhibitors upon the catalyzed niixbure-s@at norma-I curing temperatures, ta soties of samples was prepgred containing 1.5% by wib!ght of bbn-zo@l peroxide as catalyst and, Gf cou rs6, contdining gelation inhibitors. Test tubes 16 niillimlete@s iii dia-neter containing the@ mixture to a depth of 3 inches were placed in a; water bath at a temperat-are of 180' F. The temlieratiires of tl-ie mixtures- during the curin&- operat.@on were deterin'nied by means of conventional thermocouples and the time in minutes required for the; temperatures of the samples to rise froin i50, F. to the maximum, ivhich, was termed the P.@ak ex6therm, was Gbserved and is hereinafter recorded in the test designated as "E." 'khis test c6iastituteg a good indication of the rgte at whiiah the catalyzed rrilxtures will cuie -when heated. The results of the,se several tests are-,recorded a-s follows: NO@ The Iiihibitor Compouiid lyst 1501 F oxide, oxide, bath, Time in Timein hours 771 F. 771 F. 1801, F. days 771 F. Time in Timein Time in hours hours miiautes 1 -------- - 1% Lauroyl p@ridininm chloride---- 8 11-15 4Y2 2 3.2 2 -------- - 1% Cetyltrimethyl am@nonium br6. 8 4-8 4 2 3.1 mide@ 3 -------- .1@7,, Phenyltrimethyl ammonlum 8 17@ 4 2 2.9 '%Iorid6. c 4 --- .1% Trimethyl bdnzyl' immonium 8 11-15 4 1@5 3.5 chloride. 5 -------- .1% Trimethyl benzy]. ammonium 9 ------------ 7 2 --------- ---- chlbride + quinone (0.0012). 6 -------- - 5% - Trimethyl benzyl- ammonium 1.5 ------------ ------------ --------- --- ----------- hydroxid'e. 7 -------- - 1% Hydroqu' 192 216 1()2 291. 3 inone -- ------------------ 8 8------- .1% 4-tertiary butyl catechol -------- &I @ 192 216 72 26.7 9------ .- .1@y,Catechoi ------------------------ 8' 192 216 72 7: 0 10 ------- @@.1% Ascorbic acid --------- ---------- gelled at ------------ gelled at gelled at -------- once once once I I------- -1% AIph@ naphth6i ------------------ 5 ------------ 60 34 ------------ 12- Tbrtiary bttyl cateebol + n. 9 ------------ 216 72 --------- --- butyl.amine.: 13- 1% D'-O-naphthkl p-phenylene di- 9 43-120 216 7 34 17.4 TegtB- TestC- TestD- Test - Etest A- Benzovl -1%t-b@tyl .5%t-butyl Benzoyl No cata- - peroxide. hyd@oper- hydroper- peroxide vihich was-prepared fro-tn 2.2 moles of propyl- In the@ tdstg, '!the inhibitors I to 5 were quaterene glye6l, 1 mole of maleic anhydride:and 1 m'ole na;r@llammotittini'salts 6f the t3q@e co,.iterApla@t6d r.hth lic anhydride *ds em@loyed@., -T6@2'@p6rt@ hereih. The remaining compounds- reptosonted bk'@weight of this polyast6r@w@g added@lpdft':b@r 7@; ifthibitcitsi@ or pr6surh6d inhibitor@ selectbd from
[10]2,593,787 19 the prior art. Com@ounds 1 to 5 gave mixtures which were well stabilized for storage, and would withstand an accelerbted gelation test at 150' F. for 8 or 9 days. They would gel qu@ckly, even at low temperatures, when the catalysts were 5 added. V&en the catalysts of polymerization were added and the mixtures were heated to the normal curing range, the cure proceeded very rapidly and the peak of the exotherm was attained in 3 or 4 minutes. lo In contradistinction with compounds to 13, some did not substantially retard gelation of the mixtures even before the catalyst was added. Some, such as the phenolic compounds, did stabilize the uncatalyzed mixtures, but they also 15 greatly interfered with subsequent cure o catalyzed mixtures. In most cases several da were required to attain gelation at normal room. temperature and the catalyzed, mixtures even. when heated did not reach the peak of their 6xd", 20 thermal rise even in many minutes. E@'KA-.NIPLE XXVII In this example, a resin-like polyester or alkyd body resulting from conventional esterification' of- 1.2 propylene glycol in,a ratio 2.2 moles, malele 25 anhydride 1 mole, and I mole of phthalic anhydride was prepared. The polyester was cooked until it was solid or.nearly solid but was still fusible. Any of the other unsaturated polyesters or alkyds herein disclosed could be employed in this example. To this mixture was added .01 to 2L7o, e. g., .1@'o, by weight of trialkyl benzy' ammonium oxalate, e. g., triethyl or preferably trimethyl benzyl oxalate. The mixture was A liquid soluble monomer, namely styrene, wag added to the stabilized polyester in a proportion of 2 parts by weight 6f -polyester per 1 part by weight of monomer. The temperature was se- 40 lected to attain reasonable fluidity of the polyI ester, thus facilitating addition of the monomer. Usually such addition ca-n be effected at about 1201 C. However, if the polyester is inherently soft or fluid, this temperature may be reduced. 45 If a harder polyester is employed, ft may be desirable to increase the temperature. The polyester and the quaternary ammo nium oxalate readily dissolved in each other. Likewise, the polyester and- the vinylic compound, 50 namely styrene, could readily be admixed in the pres ende of the salt without danger of, premature gelling. The stabilized mixture could be stored for long periods at room temperature without gelling. 55 The stabilized mixture withstood an accelerated gelation test in the absence of catalyst 9-nd at' 150' V. for 4 days before gelation occurred. An outstanding characteristic of mixtures stabilized with quaternary ammonium oxalatb is. 60 unusual "tank life" (resistance to gelation after. the catalyst is added) coupled with remarkable ease of curing at the normal curing temperature' of the catalyzed mixture. This coftibination of characteristics is demonstrated by the following o5 tests: E@XAMPLr,, XXVIII To a set of samples of the copolymerizable miiture of the polyester and styrene of Example 2M-M stabilized with .1 % by weight of trimethyl 70 benzyl ammonium oxalate was added 1.5% by @ weight of benzoyl peroxide., These samples withstood gelation at a temperature of 71' P. for a period of 54 to 58 hours. Samples of the same mixture-similarly stabi- 75 20 lized and catalyzed when subjected to an "LPE" test in the manner already described to determine rate of cure, reached "peak exotherm" in 2.6 minu.tes. This is a vely rapid rate of cure. Th-e samples, when gelledlcan be baked at 100 or 150' C. for a period, e. g., 5 minutes to 2 hours, in order fully to harden them. The time ie4uir@d for gelling and curing, naturally, will var@, de,iendent upon the thickness or mass,of the body formed,@,the hardness desired, the catalyst emDloyed, etc. EXA)@fPLE, XXIX 400 grams of propylene maleate phthalate (prepared by heating together propylene glycol, phtiialic anhydride . and maleic anhydride fn the p.@opor-tion of 2.2 moles of glycol, one mole of phthalic anhydride and one mole of maleic anhydride, to an acid number of about 45-5 was rnixed with 200 grams of styrene and the amounts of 0.1 percent by weight inhibitor set forth in the table below. These mixtures were tested for storage stability at 1500 P. aiid for tank life at '171 F. in the presence of 1.5% benzoyl peroxide. The i,esults were as follows - Inhibitor Stability TaTik Liie. at 150' F. Tr 6thyl (benzyl ammotilurn) acid oxalate. a Over 100 hours. Di-(trimethyl benzyl ainmonium) 28 Do. oxalate. lvlono@ (trimethyl benzyl amrnoniurri) 18 Do. maleate. Di (trirnoth@,l benzyl ammonium) 16 DO. @vlono (triinethyl benzyl ammonium) 18 Do. Di (trilmethyl benzyl ailimonium) 17 '1)0. .tartarate.. Trimethyl benzyl amm nium lactate- 18 Do. T@iiriethyl benzyl am Oonium glyco- 18 1)6. late. From the above disclosure and examples, it will li@6 apparent that a wide variety of quaternary ammomum salts stabilize the contemplated polymerizable compositions without adversely affecting'the rate- of cure. Since the salts of weaker acids are less effective than salts of strong acids, it is fbund desirable to use salts of acid8 which are Eit lea@t as strong as acetic acid. As a general proposition, the soluble salts of non-oxidizing acids which have dissociation constants for the first. acid hydrogen of at least I X 10-3 are superior. Thus the halides have been found to be especially valuable. As shown above, the oxalate salts have been found to be unusually effective in promoting long "tank life." That is, polymerizable compositions containing a quaternary ammonium oxalate and a peroxide catalyst are stable at room te 'pipera tur6 for unusually @long periods of tirne and in this respect at least are superior even to the halide' Unlike many of the phenolic compounds such as hydroquinone, -the oxalic acid salts of 4uaternary ammonium bases do not interfere appreciably with the rate of cure of the catalyzed copolymerizable mixtures when the latter are heated to normai curing temperatures, e. g., 1501 F. orthereabouts. The quaternary ammonium oxalates such as trimethyl benzyl ammonium oxalate may be employed in polymerizable mixtures of any of the liquid or fus - ible.,.ethylenically unsaturated polyQsters and any of the soluble vinylically unsaturated polymerizable compounds herein disclosed. T he oxalate salts can be substituted for all or a part, e. g., l@O to 90% of any of the other quaternary ammonium @alts, e. g., trimethyl or triethyl warmed until the oxalate salt dissolved. 35 tartarate. SOIUtion took place below 1501 C.
