CA1108347A - Age-resisting polymers and their preparation by reactions involving use of certain aminomercaptans - Google Patents
Age-resisting polymers and their preparation by reactions involving use of certain aminomercaptansInfo
- Publication number
- CA1108347A CA1108347A CA282,763A CA282763A CA1108347A CA 1108347 A CA1108347 A CA 1108347A CA 282763 A CA282763 A CA 282763A CA 1108347 A CA1108347 A CA 1108347A
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- Prior art keywords
- carbon atoms
- phenyl
- polymer
- radical
- group
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08C—TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS
- C08C19/00—Chemical modification of rubber
- C08C19/20—Incorporating sulfur atoms into the molecule
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
- C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
- C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
Abstract
ABSTRACT OF THE DISCLOSURE
This invention relates to polymers which contain amino-sulfide age-resistant groups, and their prepara-tion by reaction of aminomercaptans.
This invention relates to polymers which contain amino-sulfide age-resistant groups, and their prepara-tion by reaction of aminomercaptans.
Description
E'RIOlR ART ~ ~
~____ Kline 3~$897~9 dlsl~lo~e~ polymers eon~aining relatively low levels o cert~ln N,N'-disub~3tituted p-phenylenediamine wnlts chemically bound to polymer~
as substituents of acrylic mor!omer unlts present in ther~
which unlt~ have reslstance to aging at e:levated tem-peratures. Thls resis~anee ls no~ possessed by similar polymers not conta~lng such ~ubstltuents. Ths age-re~i~ting func~ions are introduced iDto the polymers by copolymerization of acrylic monomers conta~ing such functions wi~h v~nyl or dienic monomers to prepare the polymer system.
A review ar~icle by Meyer~ Tewksbury and Pierson in HIGH PûLY~ERS, Vol. XIX, E. M~ Fetles, Ed. 9 Inter- :
science, New York, 1964, Chapter 2, dlscloses the in-corporation oiE aliphatlc mercaptans into polydi~nes to varying degrees by many workers and that ~he reactio involved was addition of ~ ercaptan to a polymeric double bond. The degrees to which the re~uïtan~ adducted polymers differed in properties from the polymeric reactants depended on the degree of lnterac~ion.
- TNE INVENTION -This lnven~iQn relates to polymer~ ~3elf-resistan~ to &ging wh~ch contain N~ disubs~i~uted-p- ~:
phenylene~diamîne groups bound to ~he re~pec~lve polymer~
-by monosulEide linkages~ It also relates to me~hods o~
preparing such compos~ tions by interact-lons o: certain am~nomercap~ans which are N, N7 -dlstlbstl~u~ed p-phenylene diamines, each containing a mercap~o alkyl function, eithe~ with a polymer radical during the course of a . free-radical polymexi~ation3 or w:Lth a polyroer contalning at least one ole~ln unit per molecule in a po~t-polymeri~
zation addition reactlon. Aminomercaptans wh:Lch are useful in the proces~ are d~scussed under the heading The Aminoa~ercaptans.
It is well known that cer~a~n N~N'-disubstitu~ed p-phenylene diamine derivati~es, when used at relatively low weight levels, as addi~ives ~o certain oxidizable oils, fat~ or polymer~, greatly enhance the resi~tance to aging or ~co oxidation of ~hese materials~ l~ence9 by iDcorporating a corr~pound c~ntaining ~uch a diamine ~ubstituen~ into a polymer by means of a chemical bond 9 one malces ~ueh polymer intrin~ically resi3tant to aging. Such age resis-tance cannot be removed from the polymer by extrac~ion, sublill~ation, decantation, filtratlon or by o~her phy~ical 2V proces~ by which conventional antiox:Ldant additives can be rem~ved from polymer~.
According to the pxesen~ inven~ion, an amino-antioxidant functlo~ is ~ncorporated into a polymer at relatively low levels by interac~ion of relatively low 3~
`3~ ~
lev21s of a non-monoaler~ c amlno-- sub~tl~uted mercaptan elther (a) as a chaln ~ransfer reagen~ reac~ing bo~h with monomer and w:l th growlllg polya~er radisals during the course of a free radlcal polym~rization or (b~ in an addition process ln wh:Lch ilt reacts with a pr~formed polymer conta~ing at least vne double bond or (c~ in a reac~lon wl~h a polydlen~ homopolymer or copol.ymer during the course of milling and curlng. All such irlteractions may be carried out e~ther in emulsion, solutiong lû dlsper~ion, or bulk media.
The pol~ymer composltions prepared by the proce~es of thls invention are preferable to known siolilar polymer composit~ons not containing chemlcally bourld ~ge resisters but protected by conven~ional age~resister~.
Hence polymers con~aining such chemirally bound age-reslster groups have a di~lnct advantage over polymers of similar ~ructure bu~ pro~ec~ed only by admixtuire wiLth conventiosaal age resister compound~.
~he pol~ymers with built-in age-resis~ance are usually composed of segmers o:E conjugated diene monomers of 4 to 10 carbon atom~ or non-conjugated cyclic or acyclic olefln monomers of 2 to 20 carbon a~om~ or vlnyl monomer~ o 2 to lV carbon atoms.
?,~3,~
Example~s of Ithe products made from the new polym~rs with bullt~ln age-resi~ter~ inolude mbber goods such as liners, gaske~, hoses and belts ~ubjscte~ to eleva~ed temperatures and/or -ln contact with oils or sslvents, and oam rubber backing~ for carpets subiected ~o dry-cleaning, etc~
The product~ wlth built-in age res~ st~ncP may be li~uid or elastomerlc solid. They may be ela~itomer~ or more resinous, depending upon ~he na~ure of ~he mononeer used and ~he 7l01erular weight, etc., and no lim~ta ~on 1~
placed on the ms~lecular weight. Those which are e~a~tomers may, when compollnded wi~ch vulcanizing ingredieIl~s; be vulcanized and used wherever rubber~ are employed. Some of these may be used as gums 9 when IlOlt vulcanized . Depend-ing upon ~he nature of the polymer~ it ~ay be u~ed ~r coatings for wood, fabrlcs, metsl~, ~tc., :Eor c:aulking~, moldings, etcO
The amount of the age-resi~ting group united - with the polymer i5 generally comparable to the amount of conventional an~ioxidant or an~iozonant employed, being generally between ~.10 and 10 par~, and preferab:Ly -~ 0. 5 ~o 5 parts per 100 par~:~ of the polymer . Th~ amount may vary depending upon the particular aminomercap.an9 ~he nature of ~:he polymer, and the use to be made of the -f~ j t~7 produc~. F~r ins~ance, an installatlon in the tropic~s wlll requlre more than the same installation whlch is ~o be lnstalled in a cold climate.
One process of the present invent~on involve~
a cha~n-transer reac~ion, in which certaln mercap~o-alkyl derivative~ of N9N'-dlsubstitu~ed-p-phenylene di-amines wh~ch have antioxidant properties intera~.t with a polymerizing monomer system to produce polymer~ eon-talr~ g these dlamino subætituents interlinked with the polymer through a monosulid~ bondO This is discussed below under the heading The Ghain Transfer React~on.
The resultan~ polymer has an intrinsic age resistance.
Such polymers may be produced by polymexizlrlg any mono-mers or mixtures of ~aonomers capable o homopolymerlz-a~ion, copolymerization or in~erpolymerizat~on by free-radical mechan~sm in pre~elace of such diamine deri~a-tive~. Such mODOmerS include con~ugated dlenes coDtain~
ing 4 to 6 or more up to~ for example,-10 carb~n atoms~
and halogen der~va~ives thereof, includi~g bu~adlene-l, 3; 2-ethylbutadiene-1~3; 2,3-dime~hyl-butadlene-1,3;
isoprene; piperylene; 1~3-hexadienes; 1,3-decadienes;
and 2-chlorobutadiene; etc. 9 and vinylic monomers Ln-cluding s~yrene, alpha methyl styrene~ divinyl benzene9 vinyl chloride, vlnyl acetate, vinyl pyr~dinesg vinyli-dene chloride, acrylonitrile~ methacrylonltrile~ ethyl :-' acrylate, methyl methacrylate, aerylic acid, methacrylic acid, maleic acid, ~6-- . ~ .
.
ilacl)nlc acid, and maleic anhydride, etc.
Another proc~ss of the present invention ln-volves another free-radical reaction of a member o~ the same family of aminomercaptans wi~h polymer substrates which contain at least one reactable double bond per polytner moleculeO This is an additi.on reaction in which the aminomercaptan reacts wi~h this double bond. This is discussed below under the heading The Free-Radical Addition Reaction.
Thus, any isotactic~ syndiotactic or atactic homopolymer or copolymer which contains a double bond reactable with the operable aminomercaptans can be used as a substrate in carrying out this addition process.
A third process relates to interaction of any of the Eoregoing polydiene homo- and co polymers with said aminomercaptans during the course of mllling and curing in the presence of rubber ehemicals including reinforcing agents and pigments, etc~ Because the reaction takes place during milling and curingl the exact nature of the reaction is not cLearly evident but a vulcanized product is obtained which is intrlnsically age-resistant. This is further discussed under the heading Milling and Curing Process.
In this process, a small amount of the amlno-mercaptan is used, such as 0.10 to 5 parts, more or less.
.
3~
The temperature rnay vary wid~ly. If the mi:Lllng is ~on-duc~ed at a sufficien~ly hiLgh ~:empera~ur~, some or all of the reac~ion may be completed before curing. The curing operation will be employed at any usl3al ~empera~ure, and ~he time required wlll depend upon th~ polymer sy~tem, ~he ~em~er~ re and the cwr:Lr3g syst~m.
The s~lnomercaptan~ usefl31 in producing the a~e-resist:Lng polymf~rs of this invention are defined by the following ormula;
Rl ~1 3 1 5 dH(C=O)~--C ~f~n--SH
R2 R4 R~ FORMIJLA 1.
which is ~omet~mes referred ~o as ZSH. In thi~ func~ion R ~ a radlcal of the c~a~s coIlsi~cing of ~a) phenyl or pher3yl which 1~ substi tuted in .
any one or srlore posl~ions with an alkyl or alkoxy group of 1 to 4 earboxl atom~ or w:ith a . radical o:E the formula N 7 in which both 1i~ and E~ may be either an - alkyl group o:E 1 to 4 carbon a~om8 or hydrogen, ~ :
or ~b) ~ cycloalkyl r~adical havlng from 5 ~o 12 carbon atorns, or ~c) a branched acycllc group comprising a chain of 1 to 12 oarbon atomsS, and each carbon m~y be subs~itutP.d wi~h 1 or 2 alkyl g oup~ of 1 'co 3 carbon atorns; ~ :
' r~ t~J
or ~d~ an allcycllc aralk~rl or aryl radioal haviDg :~r~m 7 to 14 carbon atoms~
m ~ zero or 1 1~13 a ~
R5 and ~6 are each selected from ~he group COll~ Lng o:l~ hydrogen and alkyl groups o 1 ~o 5 carboD atora~; and may be th~e ~ame or dlPferen~.
The mltlo~rcap~an may be prepared by various 10 methods. A p phenylene diamlDe substitu~ed at ore nitrogen atom wi~h ~he de~ired aryl or alicyl subs~l~uen~"
P~C6H4~ may be conver~ed ~o an N-mercap~o alkyl acyl C6H4 ~C = O~CH2)r~5H by dlrect amldation with a mercapto ac~d ~uch as ~:hioglyeolic or be~a-mercapto-proplonic acid~ Illus~ration~ o ~uch preparations are included as }~ample 1. N-Mercap~oalkyl derivative~ of similarly ~;ubsti~tJted p~phenylene diamines (as illu~trated itn Formula 1 where m3zero) may be prepared from the l~ter by treatment with ethylene sulfid~ csr propylene ~uliEide, ~r, ~n a ItW0-8tep proc~dure lnvolv~ng ~r~atmell~ o an N-substi~
~uted phenylene dlamlr1e ~i~h a ha:Lf mole equiv~len~ o a slithiLo dialdehyde uch as d, ~' di~:hioi~o~utyraldehyde ~o - form a dithio diia~ine 1 a procedure described by Ju J~
_g_ . .
.' ~ ' . . .
D'Am~i.co ,1nd W. E~ Dah]., J.Org.Chem. 409 l22~ ~l975~J; and subsequen~ reduc~ion of the diamine to an aminomercaptan ~ith lithium aluminum hyclrlde i.n refluxi.ng tetrahydrofuran ~cl procedure described by J. L. Corbin and D. E. Work, J,Org.Chern. l~ 489 (l976)~ or some other reducing system.
Such a procedure is illustrated by Exar~le 3.
The method o:~ preparing the aminomexcaptans use-Eul in this invention is not cri~ical ~o the prac~ice of this invention.
lORepresentat.-.ive amino-mercaptans whlch can be used in the present inven-~ion are listed below and the :~
numbers refer to the numbers in Table I.
No. Name .
.
I N~(4-anilino-phenyl)-~ -mercapto-acetamide ~:
II N-(4-anilino phenyl)-~mercapto-propionamide N-(4-anlsldino-phenyl)- or N-~4-phenetidino-pheny~ mercapto acetamide : V N-(4-anisidino-phenyl) ~ -rnercapto-propionamide N-(2-toluidino-phenyl) C~-mercapto-acetamide IV N-(2-toluidino-phenyl) ~ -mercapto-propionarnide III N (4-toluidino-phenyl)-~mercapto-acetamlde ::
VI N-~4-(~' J ~ - dimethyl~butylamino)-phenyl]- ~-mer-capto-acetamide ~ :
VII N-~4~ dirnethyl~butylamino~ phenyl]-~ -mer- ~ ~ .
cap~o~propionamide 3~g~ ~ :
Ncl. Name N- ~4~ani~idino-phenyl) ~mercaptc- :
propionamlde :
N- ~4~pherletldlno-phenyl~ merS~apto-pr~pionamide Another amlno mercaptan which ls descrlhed ln 13xample 3 as comp ound XIV is:
X~ NW(~ ~mercapto-f~ 3~-dimethyl~ethyl)"
N ' ~pheny 1 -p -plheny lene d lami~e ~: 10 E~samples ~E ~iamln~ sub~tr~ e~ suitable for prepara~i~
o:E a~aino-ntercap~:ans useful in thi~ inven~ioll, de~cribed and referresl to ~r number ln Table II" are:
VIIï M-phenyl-p-phenylellediamine . X N-2 ' -tolyl-p-phenylen~diaDllne XITI bi~[~ ~(4~anilinophenyl-irn~o)~., C3.
dime~hyl~ethy~3 disul~iLde ~4 1 -phe~etyl-p-phenylened~ amin~ -- IX N-4 ' -toly~-p-phenylenedlamine ~0 XI N-4 ' -ani.syl-p-phenylenediam~ne XII N- ~a ,~ ~ -d~ethyl-butyl)-p-phenylenediamlne N- (4 ' ~dirnethylamino~phenyl ) -p -phenylea~ -diamine The aminomercap~an~ may be used as anti oxidan~s following conventioDal procedure~.
h ~
Wl~hln ~he family o:f am:Lnosul~lde groups illustratcd by %S~ group of Formula 1, there i~ a sub~
family of amlno ~roups hav.ing the essential structural fea~ures of certain diamirles which are u~Pd oommercial:ly as antiozonants. These are those am:ino group~ in which at least one of the nitrogen atoms of ~he para-phenylene-dlamine ~sroup is substitutecl by an alkyl group through a ~econdary or tertlary carbon atom ~a condltlon o~
Formula 1 in wh~ch m = O, and at least either R3 or R~$, 1(3 is an alkyl group ra~ er than hydrogerl,) and the other nltrogen atom o:f thi s d~ amine group 18 a*tached either ~o an alkyl, a phenyl, or substl~u~ed phenyl group, through a ~econdary or t:ertiary carbon atom ~a carbon :~ atom havirlg no more t:han one hydrogerl atom sub~tituent).
This ub--family of aminosulfide group~ provides polymers :::
~- to which these group~ are attached wi~h an appreciable d~gree o re~istance o ozone cracking in addition to an enhanced resistance to at~ack by oth~r :Eorms of oxygen~ :
According to one reac~ion~ a mercaptoalkyl derivative o an N~ N' -disubstitu~ed diamlne is ~hemically incorporated lnto the pe)lymer by a monosllliEide bond by means of a chain ltransfer reac~ion~, The sl~eps of the reac~ion are repre~ented by the following equations:
3~
M ~b~ IM- E~U~TION 1 IM- + nM ~ IM"+; ~ P~ ~Q~1A~eION 2 P~ -t ZSH ~ P~, H -~ ZS~ EQUATION 3 ZS + M ~ ~s~ QUATION 4 ZS~ M 4~ ZS~Sq ~ PyEQU~TII:)N 5 Py + 2.SH ~ PyH ~ ZS~ ~Q17AT~ON 6 In the~e equations:
T~ ~ the ac~:~v~ing ~nltia~or radlcal M ~ ~he reactlng wlonomer ~as defined e~rlier or the chaln ~ranser proces~) n and q ~ numbers o:f molecules o.~ monon~r reacti~g wlth initial monomer radlcal P~ represents th~ relatively small number of polymer radical~ generated initiall~r Py- represents the rnajority o polymer raelic~
formed ~ wh~ch are chemically bonded ~o ~D a~o group through a ~ulfide linka~e ZS~ ~ a member of ~he family of amino~
mercaptans used; ~ which the s~ruc~ure ~-: 20 æs is de ined in fur~her detail by the am~osul;f:Lde group illus~rated :Ln Formu:La l.
-13- :
. :
: :
An illustration of such a chain transfer reaction clS a mode of incorpora~lon of an aralkyl sul1de group into polymer.s is given in the study of the inter- ' action of 2-mercaptomethyl naphthalene with a polystyren2 radical, which is to be Eoun~ in an ar~i.cle oE Plerson~
Costanza and Weinstein in J. POLYMER SCIENCE, 17, 2~1, ~1~55).
In the use of the chaln transfer method of chemlcal incorporation of amino an~ioxidant functions into polymers, one or more monomers known to polymeri~e under ,~ free radical conditions may be polymerized ln the presence of a low level of one o~ the amlno mercaptans useful in this lnventlon. The polymerizations Inay be carried out in ~ ' ,emulsion, suspension~ `bulk or solut~on type systems, Some adjustments in the polymerization recipe and¦or conditions are necessary to assure that a satisfactory ra~e of polymer formatlon and a desirable polymer molecular weight level ~`:
are achieved. Among the parameters critical to achievement of,the process are the level o~ aminomercaptan charge, which may have an effect on the degree of lnhibitlon of polymerization as well as a very deflnite effect both on the level of age~resistor function incorporated into the , polymer and on the average molecular weight of the resul tant polymerO Other adjustments which may be required in ' order to achieve such goals are the choice o a free .~ -1 3~ d radical initlator system which doe~ not pre oxidize the aminomercaptan lnto a substance which greatly retard~
or prevents polymer:i zat l~n, and ~he po~s:1 ble u~e of a solven~ or diluent addit~Ye including u~e of a comonomer chQsen to a~slJre ~he so~LI3bilit:y of ~he amino me:rcap~:an in the polymer:Lzation sy~tem. In em~llsion systems ~ some solven~s su-~h as pyridine or toluel3eg or small amoun~s of such comonolllers as styrene, acrylonitrile or acrylic e~ters can be used to advantage :or the latter purpo~.
Examples of free~radlc~l lni~ia~or sys~ems useful in the practlce Df the chain transfer process in-clude those kncwn as "redox" ~ys~ems. An example is thosa inltiators which employ a comblnation ~uch as a chelated ferrous sal~, sodium ormaldehyde sulfoxylate and an organic hydroperoxide such as cumene or para-meal~hane hydroperoxide, Thermally dissof iative compounds m~r also ~e used as polymerization in~lators for this process~ Tho~e dissociative in~t~a~ors which are not capable of oxidizing the amlnomercaptan~, such as azo compounds, for exan~ple, c,~, d '-azobls-~ obu~yrs~nitrile and ~ " ~ '-azobis- .
( ~ ~ dimethyl-valeroni~:rile)" are~ preferable over disRocla~ive peroxy ini~la~or~, such a~ ammonium persul-;. fate or tertiarg bu~ylperoxy isobu~yxa~e whiL~h are les~
-efective .
T~le reaction may be carried out in solution.
If an emulsifier is employed, a suit~ble emulsi~ier is selccted. Other compo~ents such as buEfers (to control the pH) may be used. Suspending agents are used, if desired.
These and other components such as colorin~ agents, etc.
may be used in de 5 ired amoun t 5 ~
The te~perature will depend upon the initi& or used, etc. In the "xedox" system, the temperature will generally ~ary between 0 and 50C~ Using thermally dis~
sociative initiators~ the temperature will vary from about 30 to 100 or 120Co ~ more or less, depen~ing upon ~he half life of the initiator and the particular monomer system.
~____ Kline 3~$897~9 dlsl~lo~e~ polymers eon~aining relatively low levels o cert~ln N,N'-disub~3tituted p-phenylenediamine wnlts chemically bound to polymer~
as substituents of acrylic mor!omer unlts present in ther~
which unlt~ have reslstance to aging at e:levated tem-peratures. Thls resis~anee ls no~ possessed by similar polymers not conta~lng such ~ubstltuents. Ths age-re~i~ting func~ions are introduced iDto the polymers by copolymerization of acrylic monomers conta~ing such functions wi~h v~nyl or dienic monomers to prepare the polymer system.
A review ar~icle by Meyer~ Tewksbury and Pierson in HIGH PûLY~ERS, Vol. XIX, E. M~ Fetles, Ed. 9 Inter- :
science, New York, 1964, Chapter 2, dlscloses the in-corporation oiE aliphatlc mercaptans into polydi~nes to varying degrees by many workers and that ~he reactio involved was addition of ~ ercaptan to a polymeric double bond. The degrees to which the re~uïtan~ adducted polymers differed in properties from the polymeric reactants depended on the degree of lnterac~ion.
- TNE INVENTION -This lnven~iQn relates to polymer~ ~3elf-resistan~ to &ging wh~ch contain N~ disubs~i~uted-p- ~:
phenylene~diamîne groups bound to ~he re~pec~lve polymer~
-by monosulEide linkages~ It also relates to me~hods o~
preparing such compos~ tions by interact-lons o: certain am~nomercap~ans which are N, N7 -dlstlbstl~u~ed p-phenylene diamines, each containing a mercap~o alkyl function, eithe~ with a polymer radical during the course of a . free-radical polymexi~ation3 or w:Lth a polyroer contalning at least one ole~ln unit per molecule in a po~t-polymeri~
zation addition reactlon. Aminomercaptans wh:Lch are useful in the proces~ are d~scussed under the heading The Aminoa~ercaptans.
It is well known that cer~a~n N~N'-disubstitu~ed p-phenylene diamine derivati~es, when used at relatively low weight levels, as addi~ives ~o certain oxidizable oils, fat~ or polymer~, greatly enhance the resi~tance to aging or ~co oxidation of ~hese materials~ l~ence9 by iDcorporating a corr~pound c~ntaining ~uch a diamine ~ubstituen~ into a polymer by means of a chemical bond 9 one malces ~ueh polymer intrin~ically resi3tant to aging. Such age resis-tance cannot be removed from the polymer by extrac~ion, sublill~ation, decantation, filtratlon or by o~her phy~ical 2V proces~ by which conventional antiox:Ldant additives can be rem~ved from polymer~.
According to the pxesen~ inven~ion, an amino-antioxidant functlo~ is ~ncorporated into a polymer at relatively low levels by interac~ion of relatively low 3~
`3~ ~
lev21s of a non-monoaler~ c amlno-- sub~tl~uted mercaptan elther (a) as a chaln ~ransfer reagen~ reac~ing bo~h with monomer and w:l th growlllg polya~er radisals during the course of a free radlcal polym~rization or (b~ in an addition process ln wh:Lch ilt reacts with a pr~formed polymer conta~ing at least vne double bond or (c~ in a reac~lon wl~h a polydlen~ homopolymer or copol.ymer during the course of milling and curlng. All such irlteractions may be carried out e~ther in emulsion, solutiong lû dlsper~ion, or bulk media.
The pol~ymer composltions prepared by the proce~es of thls invention are preferable to known siolilar polymer composit~ons not containing chemlcally bourld ~ge resisters but protected by conven~ional age~resister~.
Hence polymers con~aining such chemirally bound age-reslster groups have a di~lnct advantage over polymers of similar ~ructure bu~ pro~ec~ed only by admixtuire wiLth conventiosaal age resister compound~.
~he pol~ymers with built-in age-resis~ance are usually composed of segmers o:E conjugated diene monomers of 4 to 10 carbon atom~ or non-conjugated cyclic or acyclic olefln monomers of 2 to 20 carbon a~om~ or vlnyl monomer~ o 2 to lV carbon atoms.
?,~3,~
Example~s of Ithe products made from the new polym~rs with bullt~ln age-resi~ter~ inolude mbber goods such as liners, gaske~, hoses and belts ~ubjscte~ to eleva~ed temperatures and/or -ln contact with oils or sslvents, and oam rubber backing~ for carpets subiected ~o dry-cleaning, etc~
The product~ wlth built-in age res~ st~ncP may be li~uid or elastomerlc solid. They may be ela~itomer~ or more resinous, depending upon ~he na~ure of ~he mononeer used and ~he 7l01erular weight, etc., and no lim~ta ~on 1~
placed on the ms~lecular weight. Those which are e~a~tomers may, when compollnded wi~ch vulcanizing ingredieIl~s; be vulcanized and used wherever rubber~ are employed. Some of these may be used as gums 9 when IlOlt vulcanized . Depend-ing upon ~he nature of the polymer~ it ~ay be u~ed ~r coatings for wood, fabrlcs, metsl~, ~tc., :Eor c:aulking~, moldings, etcO
The amount of the age-resi~ting group united - with the polymer i5 generally comparable to the amount of conventional an~ioxidant or an~iozonant employed, being generally between ~.10 and 10 par~, and preferab:Ly -~ 0. 5 ~o 5 parts per 100 par~:~ of the polymer . Th~ amount may vary depending upon the particular aminomercap.an9 ~he nature of ~:he polymer, and the use to be made of the -f~ j t~7 produc~. F~r ins~ance, an installatlon in the tropic~s wlll requlre more than the same installation whlch is ~o be lnstalled in a cold climate.
One process of the present invent~on involve~
a cha~n-transer reac~ion, in which certaln mercap~o-alkyl derivative~ of N9N'-dlsubstitu~ed-p-phenylene di-amines wh~ch have antioxidant properties intera~.t with a polymerizing monomer system to produce polymer~ eon-talr~ g these dlamino subætituents interlinked with the polymer through a monosulid~ bondO This is discussed below under the heading The Ghain Transfer React~on.
The resultan~ polymer has an intrinsic age resistance.
Such polymers may be produced by polymexizlrlg any mono-mers or mixtures of ~aonomers capable o homopolymerlz-a~ion, copolymerization or in~erpolymerizat~on by free-radical mechan~sm in pre~elace of such diamine deri~a-tive~. Such mODOmerS include con~ugated dlenes coDtain~
ing 4 to 6 or more up to~ for example,-10 carb~n atoms~
and halogen der~va~ives thereof, includi~g bu~adlene-l, 3; 2-ethylbutadiene-1~3; 2,3-dime~hyl-butadlene-1,3;
isoprene; piperylene; 1~3-hexadienes; 1,3-decadienes;
and 2-chlorobutadiene; etc. 9 and vinylic monomers Ln-cluding s~yrene, alpha methyl styrene~ divinyl benzene9 vinyl chloride, vlnyl acetate, vinyl pyr~dinesg vinyli-dene chloride, acrylonitrile~ methacrylonltrile~ ethyl :-' acrylate, methyl methacrylate, aerylic acid, methacrylic acid, maleic acid, ~6-- . ~ .
.
ilacl)nlc acid, and maleic anhydride, etc.
Another proc~ss of the present invention ln-volves another free-radical reaction of a member o~ the same family of aminomercaptans wi~h polymer substrates which contain at least one reactable double bond per polytner moleculeO This is an additi.on reaction in which the aminomercaptan reacts wi~h this double bond. This is discussed below under the heading The Free-Radical Addition Reaction.
Thus, any isotactic~ syndiotactic or atactic homopolymer or copolymer which contains a double bond reactable with the operable aminomercaptans can be used as a substrate in carrying out this addition process.
A third process relates to interaction of any of the Eoregoing polydiene homo- and co polymers with said aminomercaptans during the course of mllling and curing in the presence of rubber ehemicals including reinforcing agents and pigments, etc~ Because the reaction takes place during milling and curingl the exact nature of the reaction is not cLearly evident but a vulcanized product is obtained which is intrlnsically age-resistant. This is further discussed under the heading Milling and Curing Process.
In this process, a small amount of the amlno-mercaptan is used, such as 0.10 to 5 parts, more or less.
.
3~
The temperature rnay vary wid~ly. If the mi:Lllng is ~on-duc~ed at a sufficien~ly hiLgh ~:empera~ur~, some or all of the reac~ion may be completed before curing. The curing operation will be employed at any usl3al ~empera~ure, and ~he time required wlll depend upon th~ polymer sy~tem, ~he ~em~er~ re and the cwr:Lr3g syst~m.
The s~lnomercaptan~ usefl31 in producing the a~e-resist:Lng polymf~rs of this invention are defined by the following ormula;
Rl ~1 3 1 5 dH(C=O)~--C ~f~n--SH
R2 R4 R~ FORMIJLA 1.
which is ~omet~mes referred ~o as ZSH. In thi~ func~ion R ~ a radlcal of the c~a~s coIlsi~cing of ~a) phenyl or pher3yl which 1~ substi tuted in .
any one or srlore posl~ions with an alkyl or alkoxy group of 1 to 4 earboxl atom~ or w:ith a . radical o:E the formula N 7 in which both 1i~ and E~ may be either an - alkyl group o:E 1 to 4 carbon a~om8 or hydrogen, ~ :
or ~b) ~ cycloalkyl r~adical havlng from 5 ~o 12 carbon atorns, or ~c) a branched acycllc group comprising a chain of 1 to 12 oarbon atomsS, and each carbon m~y be subs~itutP.d wi~h 1 or 2 alkyl g oup~ of 1 'co 3 carbon atorns; ~ :
' r~ t~J
or ~d~ an allcycllc aralk~rl or aryl radioal haviDg :~r~m 7 to 14 carbon atoms~
m ~ zero or 1 1~13 a ~
R5 and ~6 are each selected from ~he group COll~ Lng o:l~ hydrogen and alkyl groups o 1 ~o 5 carboD atora~; and may be th~e ~ame or dlPferen~.
The mltlo~rcap~an may be prepared by various 10 methods. A p phenylene diamlDe substitu~ed at ore nitrogen atom wi~h ~he de~ired aryl or alicyl subs~l~uen~"
P~C6H4~ may be conver~ed ~o an N-mercap~o alkyl acyl C6H4 ~C = O~CH2)r~5H by dlrect amldation with a mercapto ac~d ~uch as ~:hioglyeolic or be~a-mercapto-proplonic acid~ Illus~ration~ o ~uch preparations are included as }~ample 1. N-Mercap~oalkyl derivative~ of similarly ~;ubsti~tJted p~phenylene diamines (as illu~trated itn Formula 1 where m3zero) may be prepared from the l~ter by treatment with ethylene sulfid~ csr propylene ~uliEide, ~r, ~n a ItW0-8tep proc~dure lnvolv~ng ~r~atmell~ o an N-substi~
~uted phenylene dlamlr1e ~i~h a ha:Lf mole equiv~len~ o a slithiLo dialdehyde uch as d, ~' di~:hioi~o~utyraldehyde ~o - form a dithio diia~ine 1 a procedure described by Ju J~
_g_ . .
.' ~ ' . . .
D'Am~i.co ,1nd W. E~ Dah]., J.Org.Chem. 409 l22~ ~l975~J; and subsequen~ reduc~ion of the diamine to an aminomercaptan ~ith lithium aluminum hyclrlde i.n refluxi.ng tetrahydrofuran ~cl procedure described by J. L. Corbin and D. E. Work, J,Org.Chern. l~ 489 (l976)~ or some other reducing system.
Such a procedure is illustrated by Exar~le 3.
The method o:~ preparing the aminomexcaptans use-Eul in this invention is not cri~ical ~o the prac~ice of this invention.
lORepresentat.-.ive amino-mercaptans whlch can be used in the present inven-~ion are listed below and the :~
numbers refer to the numbers in Table I.
No. Name .
.
I N~(4-anilino-phenyl)-~ -mercapto-acetamide ~:
II N-(4-anilino phenyl)-~mercapto-propionamide N-(4-anlsldino-phenyl)- or N-~4-phenetidino-pheny~ mercapto acetamide : V N-(4-anisidino-phenyl) ~ -rnercapto-propionamide N-(2-toluidino-phenyl) C~-mercapto-acetamide IV N-(2-toluidino-phenyl) ~ -mercapto-propionarnide III N (4-toluidino-phenyl)-~mercapto-acetamlde ::
VI N-~4-(~' J ~ - dimethyl~butylamino)-phenyl]- ~-mer-capto-acetamide ~ :
VII N-~4~ dirnethyl~butylamino~ phenyl]-~ -mer- ~ ~ .
cap~o~propionamide 3~g~ ~ :
Ncl. Name N- ~4~ani~idino-phenyl) ~mercaptc- :
propionamlde :
N- ~4~pherletldlno-phenyl~ merS~apto-pr~pionamide Another amlno mercaptan which ls descrlhed ln 13xample 3 as comp ound XIV is:
X~ NW(~ ~mercapto-f~ 3~-dimethyl~ethyl)"
N ' ~pheny 1 -p -plheny lene d lami~e ~: 10 E~samples ~E ~iamln~ sub~tr~ e~ suitable for prepara~i~
o:E a~aino-ntercap~:ans useful in thi~ inven~ioll, de~cribed and referresl to ~r number ln Table II" are:
VIIï M-phenyl-p-phenylellediamine . X N-2 ' -tolyl-p-phenylen~diaDllne XITI bi~[~ ~(4~anilinophenyl-irn~o)~., C3.
dime~hyl~ethy~3 disul~iLde ~4 1 -phe~etyl-p-phenylened~ amin~ -- IX N-4 ' -toly~-p-phenylenedlamine ~0 XI N-4 ' -ani.syl-p-phenylenediam~ne XII N- ~a ,~ ~ -d~ethyl-butyl)-p-phenylenediamlne N- (4 ' ~dirnethylamino~phenyl ) -p -phenylea~ -diamine The aminomercap~an~ may be used as anti oxidan~s following conventioDal procedure~.
h ~
Wl~hln ~he family o:f am:Lnosul~lde groups illustratcd by %S~ group of Formula 1, there i~ a sub~
family of amlno ~roups hav.ing the essential structural fea~ures of certain diamirles which are u~Pd oommercial:ly as antiozonants. These are those am:ino group~ in which at least one of the nitrogen atoms of ~he para-phenylene-dlamine ~sroup is substitutecl by an alkyl group through a ~econdary or tertlary carbon atom ~a condltlon o~
Formula 1 in wh~ch m = O, and at least either R3 or R~$, 1(3 is an alkyl group ra~ er than hydrogerl,) and the other nltrogen atom o:f thi s d~ amine group 18 a*tached either ~o an alkyl, a phenyl, or substl~u~ed phenyl group, through a ~econdary or t:ertiary carbon atom ~a carbon :~ atom havirlg no more t:han one hydrogerl atom sub~tituent).
This ub--family of aminosulfide group~ provides polymers :::
~- to which these group~ are attached wi~h an appreciable d~gree o re~istance o ozone cracking in addition to an enhanced resistance to at~ack by oth~r :Eorms of oxygen~ :
According to one reac~ion~ a mercaptoalkyl derivative o an N~ N' -disubstitu~ed diamlne is ~hemically incorporated lnto the pe)lymer by a monosllliEide bond by means of a chain ltransfer reac~ion~, The sl~eps of the reac~ion are repre~ented by the following equations:
3~
M ~b~ IM- E~U~TION 1 IM- + nM ~ IM"+; ~ P~ ~Q~1A~eION 2 P~ -t ZSH ~ P~, H -~ ZS~ EQUATION 3 ZS + M ~ ~s~ QUATION 4 ZS~ M 4~ ZS~Sq ~ PyEQU~TII:)N 5 Py + 2.SH ~ PyH ~ ZS~ ~Q17AT~ON 6 In the~e equations:
T~ ~ the ac~:~v~ing ~nltia~or radlcal M ~ ~he reactlng wlonomer ~as defined e~rlier or the chaln ~ranser proces~) n and q ~ numbers o:f molecules o.~ monon~r reacti~g wlth initial monomer radlcal P~ represents th~ relatively small number of polymer radical~ generated initiall~r Py- represents the rnajority o polymer raelic~
formed ~ wh~ch are chemically bonded ~o ~D a~o group through a ~ulfide linka~e ZS~ ~ a member of ~he family of amino~
mercaptans used; ~ which the s~ruc~ure ~-: 20 æs is de ined in fur~her detail by the am~osul;f:Lde group illus~rated :Ln Formu:La l.
-13- :
. :
: :
An illustration of such a chain transfer reaction clS a mode of incorpora~lon of an aralkyl sul1de group into polymer.s is given in the study of the inter- ' action of 2-mercaptomethyl naphthalene with a polystyren2 radical, which is to be Eoun~ in an ar~i.cle oE Plerson~
Costanza and Weinstein in J. POLYMER SCIENCE, 17, 2~1, ~1~55).
In the use of the chaln transfer method of chemlcal incorporation of amino an~ioxidant functions into polymers, one or more monomers known to polymeri~e under ,~ free radical conditions may be polymerized ln the presence of a low level of one o~ the amlno mercaptans useful in this lnventlon. The polymerizations Inay be carried out in ~ ' ,emulsion, suspension~ `bulk or solut~on type systems, Some adjustments in the polymerization recipe and¦or conditions are necessary to assure that a satisfactory ra~e of polymer formatlon and a desirable polymer molecular weight level ~`:
are achieved. Among the parameters critical to achievement of,the process are the level o~ aminomercaptan charge, which may have an effect on the degree of lnhibitlon of polymerization as well as a very deflnite effect both on the level of age~resistor function incorporated into the , polymer and on the average molecular weight of the resul tant polymerO Other adjustments which may be required in ' order to achieve such goals are the choice o a free .~ -1 3~ d radical initlator system which doe~ not pre oxidize the aminomercaptan lnto a substance which greatly retard~
or prevents polymer:i zat l~n, and ~he po~s:1 ble u~e of a solven~ or diluent addit~Ye including u~e of a comonomer chQsen to a~slJre ~he so~LI3bilit:y of ~he amino me:rcap~:an in the polymer:Lzation sy~tem. In em~llsion systems ~ some solven~s su-~h as pyridine or toluel3eg or small amoun~s of such comonolllers as styrene, acrylonitrile or acrylic e~ters can be used to advantage :or the latter purpo~.
Examples of free~radlc~l lni~ia~or sys~ems useful in the practlce Df the chain transfer process in-clude those kncwn as "redox" ~ys~ems. An example is thosa inltiators which employ a comblnation ~uch as a chelated ferrous sal~, sodium ormaldehyde sulfoxylate and an organic hydroperoxide such as cumene or para-meal~hane hydroperoxide, Thermally dissof iative compounds m~r also ~e used as polymerization in~lators for this process~ Tho~e dissociative in~t~a~ors which are not capable of oxidizing the amlnomercaptan~, such as azo compounds, for exan~ple, c,~, d '-azobls-~ obu~yrs~nitrile and ~ " ~ '-azobis- .
( ~ ~ dimethyl-valeroni~:rile)" are~ preferable over disRocla~ive peroxy ini~la~or~, such a~ ammonium persul-;. fate or tertiarg bu~ylperoxy isobu~yxa~e whiL~h are les~
-efective .
T~le reaction may be carried out in solution.
If an emulsifier is employed, a suit~ble emulsi~ier is selccted. Other compo~ents such as buEfers (to control the pH) may be used. Suspending agents are used, if desired.
These and other components such as colorin~ agents, etc.
may be used in de 5 ired amoun t 5 ~
The te~perature will depend upon the initi& or used, etc. In the "xedox" system, the temperature will generally ~ary between 0 and 50C~ Using thermally dis~
sociative initiators~ the temperature will vary from about 30 to 100 or 120Co ~ more or less, depen~ing upon ~he half life of the initiator and the particular monomer system.
2. T~E FKEE RADICAL ADDI'rION REACTION
This procedure is an addition reaction for introducing the age resisting group into a polymer. It involves the interaction of an arylamino alkyl mercaptan with a polymer containing at least one vinylic double bond or internal double bond per polymer molecule. This inter-action is similar to tlle well-known addition of methyl mercaptan molecules to the olefin units of polydienes to form wholly or partially saturated addition products which contain methyl sulflde substituents. (5ee the article by Meyer 9 Tewksbury and Pierson in HIGH POLY*ERS, Vol. XIX
E~ M. Fettes, Edo ~ Interscience, New York, 19~4, Chapter 2, , -16~
' startir~g on page L33. There are foreign pat~nts relative ~o Lhe reaction.?
The ste-reochemical nature of polymers useful in this addition reaction may vary widely and they include polymers made from monomers containing 2 to 20 carbon atoms.
ThPy include isotactic, syndiotactic cmd atactic pol~diene homopolymers and copolymers wi~h otber conjugated or non--conjugated dienes or vinyl monomers. The method o pre-paration of such polymers is not lmporkant as long as the reactability of at least one olefin unit per polymer molecule is maintained. Polymers applicable inclucle naturally occurring polydienes such as natural rubber, gutta percha, ~alata as well as those prepared synthetically from monomers.
Preparat:ion of such polymer may be initiated thermally, by radiation or by a variety of catalysts including free-radical initiation systems or cationic, anionic or co-or~ina~ion complex ca~alysts including the Ziegler-Natta type.
Included among the polymeric substrates operative in this process are Eree-radical polymers prepared from the same monomers or mixtures of monomers which can be used in the previously described chaln-transfer process as long as Lhe resultant polymers contain at least one reactable olefin unit per polymer moleculeO Also included are polymers of ethylene, propylene or isobutylene contalning small :
;lmo~lnts of~ se~,mers of conjugated or non-conjugated acyclic )r cyclic clienes or polyolefins including isoprene, buta-diene-1,3; l-norbornene, and 1,5-cycl.ooctadiene.
Included among operative polymeric substrates prepared by non-Eree radical techni.ques are cis ancl ~rans : forms of 1,2-polybutadiene or 194-polybutadiene as well as syndiotactic or atac~ic homopolymers or copolymers prepared ~:
from butadiene-1,3; cis and trans -forms of 3,4 polyisoprene or 1~4-polyisoprene as well as syndiotactic or atactic :~ 10 homopolymers or copolymers prepared rom isoprene; analogous preparable homopolymers or copolymers o 2-ethyl-butadiene-1,3; piperylene; ~,3-dimethyl-butadiene; 2-chloro-butadiene-; 1~3; or 1,3-hexadienes.
Other polymers which may be used as substrates . include those prepared by metathesis reactions of cyclo olefins~ cyclo-diolefinsJ bicyclo-monoolefins and bicyclo- `
: dlolefins, mixtures of these withCl -olefins or copolymers of these withC~ -olefin~s, or norbornene. By the metathesis reaction is meant a polymerization in which the sub-stituents on the olefin carbon atoms of olle monomer molecule are interchanged with those o another monomer moIecule. Polymers so prepared include polypentenylene, polyoctenylene, or polyoctadlenylene.
Polymers prepared by ring opening reactions of certain cyclic olefins such as norbornene by a non~
: metathesis catalyst such as a cationic or Ziegler-Natta - 1 8r ~ ~';"~ 7 type catalyst rnay also be used as substrates for this process.
In the interaction of an amlnomercap-tan wlth a double bond already present in a polymer, this in~erac~lon may be carried out in various ways. The polymeric sub-strate may be dispersecl in an emu:Lsion, suspensiorl or solution. The addition reaction is catalyzed by free-radical initiators, either of the thermally dlssociated ~ype or the "redox" type, preferably the former, ancl including azo compounds such as bis-azoisobutyronitr~le and hydroperoxides such as cumene hydroperoxide and p-rnenthane hydroperoxlde. Temperatures necessary for effective additions of the a~inomercaptans of this in- -vention to polymeric substrates are those necessary for continuous dissociation of the particular catalyst used, and vary from about Q C. to about 100 C. The time of reaction required depends upon many factors including the catalyst used, its~co~centratipn, the level of mer-captan addition required and Eor the case of additiorl to s~ereospecific polydienes, the acceptable clegree of isomerization of polymer configuration.
In the adclition reaction the level of amino-mercaptan charged may be from 0.1 to 10.0 parts or preferably 0.5 to 5 parts per hundred parts of polymer (p.h.p.), and the level of catalyst~ if thermally dis-sociative3 may be from 0.05 to 59 and preferably Q.05 J
to 1.0 p.h.p. The reactlon temp~rature, using a thermally dissociative catalyst, may be 20 to 120 C. 3 and is prefer-ably 30~ to 80 C. The polymer system should be free of appreciable levels of reactable olefinlc monomers and of free~ra~ical inhibitors in order to ob~ain a desired level of mercap~an addition in reasonable time. Such reactions can be carried ou~ in emuls~on~ suspen~ion or solu~ion media.
This procedure is an addition reaction for introducing the age resisting group into a polymer. It involves the interaction of an arylamino alkyl mercaptan with a polymer containing at least one vinylic double bond or internal double bond per polymer molecule. This inter-action is similar to tlle well-known addition of methyl mercaptan molecules to the olefin units of polydienes to form wholly or partially saturated addition products which contain methyl sulflde substituents. (5ee the article by Meyer 9 Tewksbury and Pierson in HIGH POLY*ERS, Vol. XIX
E~ M. Fettes, Edo ~ Interscience, New York, 19~4, Chapter 2, , -16~
' startir~g on page L33. There are foreign pat~nts relative ~o Lhe reaction.?
The ste-reochemical nature of polymers useful in this addition reaction may vary widely and they include polymers made from monomers containing 2 to 20 carbon atoms.
ThPy include isotactic, syndiotactic cmd atactic pol~diene homopolymers and copolymers wi~h otber conjugated or non--conjugated dienes or vinyl monomers. The method o pre-paration of such polymers is not lmporkant as long as the reactability of at least one olefin unit per polymer molecule is maintained. Polymers applicable inclucle naturally occurring polydienes such as natural rubber, gutta percha, ~alata as well as those prepared synthetically from monomers.
Preparat:ion of such polymer may be initiated thermally, by radiation or by a variety of catalysts including free-radical initiation systems or cationic, anionic or co-or~ina~ion complex ca~alysts including the Ziegler-Natta type.
Included among the polymeric substrates operative in this process are Eree-radical polymers prepared from the same monomers or mixtures of monomers which can be used in the previously described chaln-transfer process as long as Lhe resultant polymers contain at least one reactable olefin unit per polymer moleculeO Also included are polymers of ethylene, propylene or isobutylene contalning small :
;lmo~lnts of~ se~,mers of conjugated or non-conjugated acyclic )r cyclic clienes or polyolefins including isoprene, buta-diene-1,3; l-norbornene, and 1,5-cycl.ooctadiene.
Included among operative polymeric substrates prepared by non-Eree radical techni.ques are cis ancl ~rans : forms of 1,2-polybutadiene or 194-polybutadiene as well as syndiotactic or atac~ic homopolymers or copolymers prepared ~:
from butadiene-1,3; cis and trans -forms of 3,4 polyisoprene or 1~4-polyisoprene as well as syndiotactic or atactic :~ 10 homopolymers or copolymers prepared rom isoprene; analogous preparable homopolymers or copolymers o 2-ethyl-butadiene-1,3; piperylene; ~,3-dimethyl-butadiene; 2-chloro-butadiene-; 1~3; or 1,3-hexadienes.
Other polymers which may be used as substrates . include those prepared by metathesis reactions of cyclo olefins~ cyclo-diolefinsJ bicyclo-monoolefins and bicyclo- `
: dlolefins, mixtures of these withCl -olefins or copolymers of these withC~ -olefin~s, or norbornene. By the metathesis reaction is meant a polymerization in which the sub-stituents on the olefin carbon atoms of olle monomer molecule are interchanged with those o another monomer moIecule. Polymers so prepared include polypentenylene, polyoctenylene, or polyoctadlenylene.
Polymers prepared by ring opening reactions of certain cyclic olefins such as norbornene by a non~
: metathesis catalyst such as a cationic or Ziegler-Natta - 1 8r ~ ~';"~ 7 type catalyst rnay also be used as substrates for this process.
In the interaction of an amlnomercap-tan wlth a double bond already present in a polymer, this in~erac~lon may be carried out in various ways. The polymeric sub-strate may be dispersecl in an emu:Lsion, suspensiorl or solution. The addition reaction is catalyzed by free-radical initiators, either of the thermally dlssociated ~ype or the "redox" type, preferably the former, ancl including azo compounds such as bis-azoisobutyronitr~le and hydroperoxides such as cumene hydroperoxide and p-rnenthane hydroperoxlde. Temperatures necessary for effective additions of the a~inomercaptans of this in- -vention to polymeric substrates are those necessary for continuous dissociation of the particular catalyst used, and vary from about Q C. to about 100 C. The time of reaction required depends upon many factors including the catalyst used, its~co~centratipn, the level of mer-captan addition required and Eor the case of additiorl to s~ereospecific polydienes, the acceptable clegree of isomerization of polymer configuration.
In the adclition reaction the level of amino-mercaptan charged may be from 0.1 to 10.0 parts or preferably 0.5 to 5 parts per hundred parts of polymer (p.h.p.), and the level of catalyst~ if thermally dis-sociative3 may be from 0.05 to 59 and preferably Q.05 J
to 1.0 p.h.p. The reactlon temp~rature, using a thermally dissociative catalyst, may be 20 to 120 C. 3 and is prefer-ably 30~ to 80 C. The polymer system should be free of appreciable levels of reactable olefinlc monomers and of free~ra~ical inhibitors in order to ob~ain a desired level of mercap~an addition in reasonable time. Such reactions can be carried ou~ in emuls~on~ suspen~ion or solu~ion media.
3. THE MILLING AND CURING PROCESS
In this process~ the aminomercaptan ls added to a millable elastomeric diene homopolymer or copolymer on a rubbPr mill, for example a Banbury, in presence of chernical addltives used conventionally for curing or vul-canizlng rubber, ln the presence of air and at conventlonal rubber milling temperatures, in the presen~e or absence of reinforcing pigments. Su~h rubber stock is then cured in an oven or press at a temperature normally used in the art for production of a vulcanizate, as for example, between 250 F. and 350 F.
Representative polymers and copolym~rs useful in the process include polybutadiene~ polyisoprene, isoprene-styrene, butadiene-styrene, isoprene-acrylonitrile, buta-` diene-acrylonitrile (referred to herein~ as elastomers) ln which a major portion ls butadiene or isoprene. The ' .
vulcanizate when extracted with a solvent such as acetone or methyl ethyl ketone in order to free i~ of non rubber additives, has a resls~anoe to oxidation or aging very much greater than that of a vulcanizate which has been prepared ln the presence o:~ a conveTltional an~ioxidant, suc.h as 2,6-di-t butyl-p-cresol which has been removed from the vulcanl~ate by extraction. Ia~orporatlon of age-resistor functions by this pro~ess ls illustrated by Example 11~ It is therefore evident that th~ amino-10 mercaptan used is incorporated into such a polymervulcanizate dur~ng the combined milling/cur~ng process.
AG -R15ISTA~T ~OI~MrR5 The age-resistant polymers o~ this invention obtained by the several processes described may be de~ined by the formula ZSP in which ZS is the aminosulfide group of Formula 1, namely3 l ~ 15 RNH ~ NH(C~O)m--C -- (C)2~ _ S
R2 R4 R~
defined above, and P, whieh has been removed, represents the polymeric portion of the age-resistant polymers referred to :~
herein~ Thus~ the age-resistant polymers may be represented by ~he ormula Rl tR3 ~5 RNH ~ NH(CaO)m--C --(C) --SP
R2 R~ R6 -Zl Examples of the preparation of age-re~ist nt polymers by ~he chain-tran~fer reactior; are Examples 4,5,6 and 7.
Examples of the preparation o age-re~istant polymer~ by ~he addition reac~ion are Examples 8 and gO
Example 10 i~ lustrates the incorporation o:f age-resi~tant aminosulfide group~ into the polymers by milliDg and curing.
Example ll illustrates the use of a~lnomereapt:ans of ~his invention as conventional age resl~ters~
Examples of the preparation o some of the amino-mercaptans useful ~n ~h~s inven~ionD ~lld intermediates used :~ . ln their preparation, are illustrated by Exa~ple 1, 2 and 3.
N- (4-ANILINO rPHENYL~ ME~AP~'O--PROPIONAMII)E
, .
- A mixture of 1804 gram~ of N-phenyl-p-pheDylene diamine, 1006 gram~ o ~k~ mercaptoprop:ioTlic acid and 120 `` milllliters of xylene (technical grade) was heated to reflux ~about 140C . ~ under nitrogen atmosphere " with stirring~ A 1.6 milliliter quantity of water ~90~ of theory) was removed from ~his mixture by a2~0trQpic dl~illation ~hrough a ~7igrsux column wlth the ald of a Dean-Stark ~rap, durlng a 13-hour period. A ~olid produc~ was isoïated in 18. 7 gram~ quantity from the reaction mixture by coollng ~ 3~
the latter, pouring into hexane, collecting the resultant crystalline product: by ~iltr~tion~ washing the crwshed crystalllne product wlth more hexane and evapor~ting to dryness. The product was recry~allized from hot toluene to 17.6 grams (64.5%) of white platelets melting at 98.3-9~.5C. The resultant new compound, N-(4-anilino~phellyl)-beta mercaptoproplonamide, sometimes re:erred to hereater as MPDA, had mereaptan as~y of 9308~/o of ~heoretical, on ;~he basis of a potentiometric titrat~on with an i90p~0pyl alcohol solution of silver nitrate~ ollowing a method described by R. M. Pierson, A. J. Costanza and A. H.
Weins ein, J. Polymer Sci., 17, 234 (1955).
In a manner slmilar to that describ~d above, a series oiE aminomercaptaDs were prepared by u~e of the appropria~e diamine and mercapto-acld substra~e~. They are characterized in Table I. Those product~ wh~ch did not crystallize readily were freed of mercapto-acid substrate by extracting their benzene solutlons with aqueous sodium carbvnate~ and then wi~h water before isolating.
' ~, -~7Z- ' 1 O ~ `D 09 ~ ~:; oo ~ ~
^ :~ ~ l~ ~
~ ~ ~ ~l o c~
~ ~1 o c~ ~ os z ~
~ c~
E~
ly;
t~3 ~ ~ o~
::l u . ~ .
u~
u~
~ ~ O ~
a: O ~ o~
<~
. . ~ E~ ~ ~ u~ ~ o ~il ¢, 1 H u~
, ~ ~ ~ ~ O
a~ ~ 3 P~ ~I F~IS
O J~
~ ~ ) O ~ 7 e~ 1~ 1 v ~, ~ U~ ~ ~ ~ ~ pq X
~7 O
~ ~ ll ~ C~ ~C ~
Z; ~ ~
E~ ~ 01 O
æ P~~ ~ ~ ~ ~ ~ ~ ,, ~ P~ o o :
~ ~ ~ o o~
H H
O H ~ ~ H ~1 ~
æ ~ ~ w H ;~
3~
EXAMPLF. 2 ALK~ OR ~YL-~UP~STITUTED-p-PHENYLENE _LAMINE SUBSTRATES
The diamine substra~es used ~or prepara~i.on of ~he aminomerc~ptans of Table I and ~he aminomercaptan ~IV, whose preparation is described in Example 3, are char~
~cterized in Table II. Referring to ~lle examples of -~
T~ble II, they were either ~vailable as the free amine (VIII) or i~s hydrochloride ~XI~. Compounds IX and X
were prepared from p-nitrochlorobenzene and the appro priate toluidine according to a method described by R~ H.
Kline, RUBBER CHEM. TE~HNOL. 46, 96 (1973). Compound XII was prepared by reductive alkylation o~ p-amino-acetanilide wi-th methyl isobu~l ketone according to a general procedure discu:ssed by Morris Freifelder in PRACTI~A~ CATALYTIC HYDROGENATION, Wiley-Interscience, .
New York, 1971, ~h 17, page 346.
TA~LE II
DIAMIN SUBSTRATES
NO. STRUCTURE MELTING USED FOR PREPARA
POINT, CO TION OF AMINO- ~ :
RNH Nm2 MERCAPTAN NUMæER:
in which R-VIII Phenyl 76-77 I~ II, XIV
IX p-Tolyl 115~116 III
X o-Tolyl 58.5 IV
XI p-Anisyl 102-103 V
XII 1,3-Dimethyl-butyl 43-44 VI, VII ~ :
~25-.: ; ' ;;
~: .
N-~BETA-MF.~CAPTO-BETA~BETA-DIMETHYL-ETII~L), N'-P}IENYL~PARA-PHENYLENEDIAMINE _ An intermediate compound; bis-[beta-(4-anilino-phenyl-imlno)-alpha,alpha-dimethylethyl~ disulfide was first preparecl as follows:
Following a procedure described for preparation ~ .
by J. J. D'Amico and W, E Dahl, J. Org~Chem., 40 1224 ~].975)~c~ -dithiobis-isobutyraldehyde, which was freshly prepared as described from isobutyraldehyde and sulfur monochloride, were interacted with two mole equivalents of N-phenyl-p-phenylenediamine (VIII), at ambient temperature, in methanol solventO The product~ obtained in 89 per cent yield~ ~rom a water-washed ben~ene extract o the reaction mixture wa~s a dark-brown uncrystallizable semi- - :
solid fora~ of bis-[beta-(4-anilopllenyl-amino)-alpha, alpha-dimethylethyl] disulfide.
Thls diamino clisulfide was reduced to a mercaptan as follows: A solution of 39.2 grams of compound (prepared as above) in 150 milliliters of anhydrous tetrahydrofuran was added dropwise, with stirring, under i.nert atmosphere, to a re.~luxing solution o~ 5.0 grams of lithlum aluminum hydride in 200 more mllliliters of the same solvent;
over a 4~-min-lte period. The reaction mixture was per-mitted to reflux ~or several more hours. The conditions used for this reaction and the subsequent product work-up -2~-.
' 3'~,A ;i~
a:re 1.n acoordance wi-th conditions described for preparation . o.~ analogous compounds by Corbin and Work, J.Org. Chem.
41, 4&9 (1976). The excess LiAlHIIwas decomposed wi-th aqueous sodlum potassium -tar-tra-te, and the produc-t isolated .
from a wa-ter-washed die-thyl e-ther extrac-t by vacuum evaporation. In this rnanner, 37~2 grams of a -th:ick dark~bro~ syrup, con-taining 47 percen~t of mercaptan, namely, N-~be-ta-mercap-to-be-ta, beta-dime-thyl-ethyl), N'-phenyl-para-phenylenediamine, Compound XIV of Table II, having the -theoretical molecular weight o~ 272, was isolated.
,~ INCORPORATION OF AMINOMERCAPTANS INTO
In two separa-te experiments, 1.00 par-t by weigh-t of Compounds I or II of Table I, corrected ~or active mercaptan conten-t, was ch.arged into vials each containing 100 parts of styrene, O.10 par-t OL bis-azoisobutyron,icrile and 5.0 parts o~ pyridine. In a -third vial~ the same O proportions of' all ingredients except aminomercaptan were charged. The vials were sealed under ni-trogen atmosphere and tumbled for 16 hours in a wa-ter bath at 50C. Low conversion of polys-tyren,e samples were isola-ted from each o~ -the -three solutions by coagula-ting into isopropyl .~, alcohol.
-27- :
: : :
~ 31~
On the basis of inherent viscosity determinations made on benzene solutions ~f driecl polystyrene samples~
the number av~rage molecular weights were determined for each sample, using an ~quation developed by F ~. Mayo, J.Am.Chem.Soc. 65a 2324 (1943~o In this way, i-t was determined that polyrner made in the presence o~ Compound IL (MPDA) had a molecular weight of 17,lOO as compared with a value of 266,000 for the con~
trol polymer. By subs~ituting these molecular weight values : lO into an equa~ion developed by the cited author, a chain : transfer constant (T~Co)~ representing a ratio of reactivity of Compound II over that o~ a styrene monomer molecule wi~h a polystyrene radical, was calculated. The ~act that the T.C~ value or Compound II at 50C. obtained in this manner wa~ an appreciable value, namely ~.40, indicated that Compound II had reacted appreciably with the polymer by means o an incorporating mechanism. By slmilar means, it ~ . was shown that Compound I ~MAD~), with a T.C. value of ; 0.273 had an appreciable, if somewhat lesser, ~endency to ~- 20 ineorporate into polystyrene.
INCnRPORATION OF MPDA I~TO ISOPRENE/STYRENE
: A series o:E emulsion copolymeri~ations A to E were carried out in four-ounce screw~cap b~ttles using ~` 20.0 gr~ms mon~mer charges and containing the following ingredients in commo~l~ all lis~ed in parts per hundred of monomer:
Isoprene - 75.0 Styrene ~ 25.0 Pyridine - 5.00 Potassium stearate - S.OO
Distilled water -200 Variable ingredients were also charged into these bottles, as lndicated in Table III on a parts per hundred o monomer basls. Converslon levels o~tained, after the bottles were swept with nitrogen, sealed and tumbled or 17 hours in a water hath at the prescribed te~peratures9 are also recorded in this table.
TABLE III
VARIABLES A B C D E
Ammonium persulfate - 0.~0. 0.40 - -; Azobis-isobutyronitrile 0.40 - - 0.40 0.40 MPDAa - 2.00 2.00 - 2.00 ::
Reaction temperature, C. 50 - SO 70 70 70 Conversion to polymer, % 76 0 26 97 80 a. On basis of 100% mercaptan activiky.
Efficien~y of incorpor~tion of MPDA into isoprene/
styrene~ olymers _ A series o~ copolymers o~ substantlally 75~/0 of isopxene: 25% styrene were prepared as in Example 5~
recipe D9 with variables indicated in Table IV including MPDA charge levels. Polymers were coagulated into isopropyl alcohol3 freed of non-polymeric substances by repeated extractions with hot isopropyl alcohol, and -2~-3f-q 7 vacuum evaporclted.
Leve:ls oE ~-anil:Lnophenyl-carbamyl units in-corporated i.nto polymers, on a parts per hundred (p,h.r.) basis, were determined on basis of a coLorometric assay of the intensity of blue-colored qulnone-imlne chromophore developed by oxid~tion o~ chloroform solutions of polymer~
wi~h benzoyl peroxide.
Thin films of polymers of known welght of from :l to 1.5 grams were made by evaporating benzene cements of polymers on~o tared aluminum sheets having a surface area of 1500 cm2O These sheets were lnserted into the chambers of a typical oxygen absorptlon apparatus.
Oxidation resistance ~0~O~ values for these polymers were determined as the number of hours required for absorpeion oE 1 per cent by weight of oxygen by a polymer sample from oxygen atmosphere at a given temperature9 in this case 90C.
: Data relatlng to efficiency of incorporation of amino groups and to oxidation resistance of these polymers are also included in Table IV~ Data shows the marked enhancing effect of incorporated MPDA on polymer oxidation resistance.
.; .
TABLE IV
PARTS BY i~EIGHT I.N
P~CIPE VARIAP~LES F G H J K
~_ _ _ _ MPDA 1.00 2.00 3.00 2.00 - :
n-Dodecyl mercaptan - - - 1, 5a Pyridine 5~- 5,0 5,0 _ 5~0 POLYMERIZATION ~ESULTS:
Conversion, % 87 80 18 94 92 P'z'n time, hrs. at 70Co 17 17 17 17 7
In this process~ the aminomercaptan ls added to a millable elastomeric diene homopolymer or copolymer on a rubbPr mill, for example a Banbury, in presence of chernical addltives used conventionally for curing or vul-canizlng rubber, ln the presence of air and at conventlonal rubber milling temperatures, in the presen~e or absence of reinforcing pigments. Su~h rubber stock is then cured in an oven or press at a temperature normally used in the art for production of a vulcanizate, as for example, between 250 F. and 350 F.
Representative polymers and copolym~rs useful in the process include polybutadiene~ polyisoprene, isoprene-styrene, butadiene-styrene, isoprene-acrylonitrile, buta-` diene-acrylonitrile (referred to herein~ as elastomers) ln which a major portion ls butadiene or isoprene. The ' .
vulcanizate when extracted with a solvent such as acetone or methyl ethyl ketone in order to free i~ of non rubber additives, has a resls~anoe to oxidation or aging very much greater than that of a vulcanizate which has been prepared ln the presence o:~ a conveTltional an~ioxidant, suc.h as 2,6-di-t butyl-p-cresol which has been removed from the vulcanl~ate by extraction. Ia~orporatlon of age-resistor functions by this pro~ess ls illustrated by Example 11~ It is therefore evident that th~ amino-10 mercaptan used is incorporated into such a polymervulcanizate dur~ng the combined milling/cur~ng process.
AG -R15ISTA~T ~OI~MrR5 The age-resistant polymers o~ this invention obtained by the several processes described may be de~ined by the formula ZSP in which ZS is the aminosulfide group of Formula 1, namely3 l ~ 15 RNH ~ NH(C~O)m--C -- (C)2~ _ S
R2 R4 R~
defined above, and P, whieh has been removed, represents the polymeric portion of the age-resistant polymers referred to :~
herein~ Thus~ the age-resistant polymers may be represented by ~he ormula Rl tR3 ~5 RNH ~ NH(CaO)m--C --(C) --SP
R2 R~ R6 -Zl Examples of the preparation of age-re~ist nt polymers by ~he chain-tran~fer reactior; are Examples 4,5,6 and 7.
Examples of the preparation o age-re~istant polymer~ by ~he addition reac~ion are Examples 8 and gO
Example 10 i~ lustrates the incorporation o:f age-resi~tant aminosulfide group~ into the polymers by milliDg and curing.
Example ll illustrates the use of a~lnomereapt:ans of ~his invention as conventional age resl~ters~
Examples of the preparation o some of the amino-mercaptans useful ~n ~h~s inven~ionD ~lld intermediates used :~ . ln their preparation, are illustrated by Exa~ple 1, 2 and 3.
N- (4-ANILINO rPHENYL~ ME~AP~'O--PROPIONAMII)E
, .
- A mixture of 1804 gram~ of N-phenyl-p-pheDylene diamine, 1006 gram~ o ~k~ mercaptoprop:ioTlic acid and 120 `` milllliters of xylene (technical grade) was heated to reflux ~about 140C . ~ under nitrogen atmosphere " with stirring~ A 1.6 milliliter quantity of water ~90~ of theory) was removed from ~his mixture by a2~0trQpic dl~illation ~hrough a ~7igrsux column wlth the ald of a Dean-Stark ~rap, durlng a 13-hour period. A ~olid produc~ was isoïated in 18. 7 gram~ quantity from the reaction mixture by coollng ~ 3~
the latter, pouring into hexane, collecting the resultant crystalline product: by ~iltr~tion~ washing the crwshed crystalllne product wlth more hexane and evapor~ting to dryness. The product was recry~allized from hot toluene to 17.6 grams (64.5%) of white platelets melting at 98.3-9~.5C. The resultant new compound, N-(4-anilino~phellyl)-beta mercaptoproplonamide, sometimes re:erred to hereater as MPDA, had mereaptan as~y of 9308~/o of ~heoretical, on ;~he basis of a potentiometric titrat~on with an i90p~0pyl alcohol solution of silver nitrate~ ollowing a method described by R. M. Pierson, A. J. Costanza and A. H.
Weins ein, J. Polymer Sci., 17, 234 (1955).
In a manner slmilar to that describ~d above, a series oiE aminomercaptaDs were prepared by u~e of the appropria~e diamine and mercapto-acld substra~e~. They are characterized in Table I. Those product~ wh~ch did not crystallize readily were freed of mercapto-acid substrate by extracting their benzene solutlons with aqueous sodium carbvnate~ and then wi~h water before isolating.
' ~, -~7Z- ' 1 O ~ `D 09 ~ ~:; oo ~ ~
^ :~ ~ l~ ~
~ ~ ~ ~l o c~
~ ~1 o c~ ~ os z ~
~ c~
E~
ly;
t~3 ~ ~ o~
::l u . ~ .
u~
u~
~ ~ O ~
a: O ~ o~
<~
. . ~ E~ ~ ~ u~ ~ o ~il ¢, 1 H u~
, ~ ~ ~ ~ O
a~ ~ 3 P~ ~I F~IS
O J~
~ ~ ) O ~ 7 e~ 1~ 1 v ~, ~ U~ ~ ~ ~ ~ pq X
~7 O
~ ~ ll ~ C~ ~C ~
Z; ~ ~
E~ ~ 01 O
æ P~~ ~ ~ ~ ~ ~ ~ ,, ~ P~ o o :
~ ~ ~ o o~
H H
O H ~ ~ H ~1 ~
æ ~ ~ w H ;~
3~
EXAMPLF. 2 ALK~ OR ~YL-~UP~STITUTED-p-PHENYLENE _LAMINE SUBSTRATES
The diamine substra~es used ~or prepara~i.on of ~he aminomerc~ptans of Table I and ~he aminomercaptan ~IV, whose preparation is described in Example 3, are char~
~cterized in Table II. Referring to ~lle examples of -~
T~ble II, they were either ~vailable as the free amine (VIII) or i~s hydrochloride ~XI~. Compounds IX and X
were prepared from p-nitrochlorobenzene and the appro priate toluidine according to a method described by R~ H.
Kline, RUBBER CHEM. TE~HNOL. 46, 96 (1973). Compound XII was prepared by reductive alkylation o~ p-amino-acetanilide wi-th methyl isobu~l ketone according to a general procedure discu:ssed by Morris Freifelder in PRACTI~A~ CATALYTIC HYDROGENATION, Wiley-Interscience, .
New York, 1971, ~h 17, page 346.
TA~LE II
DIAMIN SUBSTRATES
NO. STRUCTURE MELTING USED FOR PREPARA
POINT, CO TION OF AMINO- ~ :
RNH Nm2 MERCAPTAN NUMæER:
in which R-VIII Phenyl 76-77 I~ II, XIV
IX p-Tolyl 115~116 III
X o-Tolyl 58.5 IV
XI p-Anisyl 102-103 V
XII 1,3-Dimethyl-butyl 43-44 VI, VII ~ :
~25-.: ; ' ;;
~: .
N-~BETA-MF.~CAPTO-BETA~BETA-DIMETHYL-ETII~L), N'-P}IENYL~PARA-PHENYLENEDIAMINE _ An intermediate compound; bis-[beta-(4-anilino-phenyl-imlno)-alpha,alpha-dimethylethyl~ disulfide was first preparecl as follows:
Following a procedure described for preparation ~ .
by J. J. D'Amico and W, E Dahl, J. Org~Chem., 40 1224 ~].975)~c~ -dithiobis-isobutyraldehyde, which was freshly prepared as described from isobutyraldehyde and sulfur monochloride, were interacted with two mole equivalents of N-phenyl-p-phenylenediamine (VIII), at ambient temperature, in methanol solventO The product~ obtained in 89 per cent yield~ ~rom a water-washed ben~ene extract o the reaction mixture wa~s a dark-brown uncrystallizable semi- - :
solid fora~ of bis-[beta-(4-anilopllenyl-amino)-alpha, alpha-dimethylethyl] disulfide.
Thls diamino clisulfide was reduced to a mercaptan as follows: A solution of 39.2 grams of compound (prepared as above) in 150 milliliters of anhydrous tetrahydrofuran was added dropwise, with stirring, under i.nert atmosphere, to a re.~luxing solution o~ 5.0 grams of lithlum aluminum hydride in 200 more mllliliters of the same solvent;
over a 4~-min-lte period. The reaction mixture was per-mitted to reflux ~or several more hours. The conditions used for this reaction and the subsequent product work-up -2~-.
' 3'~,A ;i~
a:re 1.n acoordance wi-th conditions described for preparation . o.~ analogous compounds by Corbin and Work, J.Org. Chem.
41, 4&9 (1976). The excess LiAlHIIwas decomposed wi-th aqueous sodlum potassium -tar-tra-te, and the produc-t isolated .
from a wa-ter-washed die-thyl e-ther extrac-t by vacuum evaporation. In this rnanner, 37~2 grams of a -th:ick dark~bro~ syrup, con-taining 47 percen~t of mercaptan, namely, N-~be-ta-mercap-to-be-ta, beta-dime-thyl-ethyl), N'-phenyl-para-phenylenediamine, Compound XIV of Table II, having the -theoretical molecular weight o~ 272, was isolated.
,~ INCORPORATION OF AMINOMERCAPTANS INTO
In two separa-te experiments, 1.00 par-t by weigh-t of Compounds I or II of Table I, corrected ~or active mercaptan conten-t, was ch.arged into vials each containing 100 parts of styrene, O.10 par-t OL bis-azoisobutyron,icrile and 5.0 parts o~ pyridine. In a -third vial~ the same O proportions of' all ingredients except aminomercaptan were charged. The vials were sealed under ni-trogen atmosphere and tumbled for 16 hours in a wa-ter bath at 50C. Low conversion of polys-tyren,e samples were isola-ted from each o~ -the -three solutions by coagula-ting into isopropyl .~, alcohol.
-27- :
: : :
~ 31~
On the basis of inherent viscosity determinations made on benzene solutions ~f driecl polystyrene samples~
the number av~rage molecular weights were determined for each sample, using an ~quation developed by F ~. Mayo, J.Am.Chem.Soc. 65a 2324 (1943~o In this way, i-t was determined that polyrner made in the presence o~ Compound IL (MPDA) had a molecular weight of 17,lOO as compared with a value of 266,000 for the con~
trol polymer. By subs~ituting these molecular weight values : lO into an equa~ion developed by the cited author, a chain : transfer constant (T~Co)~ representing a ratio of reactivity of Compound II over that o~ a styrene monomer molecule wi~h a polystyrene radical, was calculated. The ~act that the T.C~ value or Compound II at 50C. obtained in this manner wa~ an appreciable value, namely ~.40, indicated that Compound II had reacted appreciably with the polymer by means o an incorporating mechanism. By slmilar means, it ~ . was shown that Compound I ~MAD~), with a T.C. value of ; 0.273 had an appreciable, if somewhat lesser, ~endency to ~- 20 ineorporate into polystyrene.
INCnRPORATION OF MPDA I~TO ISOPRENE/STYRENE
: A series o:E emulsion copolymeri~ations A to E were carried out in four-ounce screw~cap b~ttles using ~` 20.0 gr~ms mon~mer charges and containing the following ingredients in commo~l~ all lis~ed in parts per hundred of monomer:
Isoprene - 75.0 Styrene ~ 25.0 Pyridine - 5.00 Potassium stearate - S.OO
Distilled water -200 Variable ingredients were also charged into these bottles, as lndicated in Table III on a parts per hundred o monomer basls. Converslon levels o~tained, after the bottles were swept with nitrogen, sealed and tumbled or 17 hours in a water hath at the prescribed te~peratures9 are also recorded in this table.
TABLE III
VARIABLES A B C D E
Ammonium persulfate - 0.~0. 0.40 - -; Azobis-isobutyronitrile 0.40 - - 0.40 0.40 MPDAa - 2.00 2.00 - 2.00 ::
Reaction temperature, C. 50 - SO 70 70 70 Conversion to polymer, % 76 0 26 97 80 a. On basis of 100% mercaptan activiky.
Efficien~y of incorpor~tion of MPDA into isoprene/
styrene~ olymers _ A series o~ copolymers o~ substantlally 75~/0 of isopxene: 25% styrene were prepared as in Example 5~
recipe D9 with variables indicated in Table IV including MPDA charge levels. Polymers were coagulated into isopropyl alcohol3 freed of non-polymeric substances by repeated extractions with hot isopropyl alcohol, and -2~-3f-q 7 vacuum evaporclted.
Leve:ls oE ~-anil:Lnophenyl-carbamyl units in-corporated i.nto polymers, on a parts per hundred (p,h.r.) basis, were determined on basis of a coLorometric assay of the intensity of blue-colored qulnone-imlne chromophore developed by oxid~tion o~ chloroform solutions of polymer~
wi~h benzoyl peroxide.
Thin films of polymers of known welght of from :l to 1.5 grams were made by evaporating benzene cements of polymers on~o tared aluminum sheets having a surface area of 1500 cm2O These sheets were lnserted into the chambers of a typical oxygen absorptlon apparatus.
Oxidation resistance ~0~O~ values for these polymers were determined as the number of hours required for absorpeion oE 1 per cent by weight of oxygen by a polymer sample from oxygen atmosphere at a given temperature9 in this case 90C.
: Data relatlng to efficiency of incorporation of amino groups and to oxidation resistance of these polymers are also included in Table IV~ Data shows the marked enhancing effect of incorporated MPDA on polymer oxidation resistance.
.; .
TABLE IV
PARTS BY i~EIGHT I.N
P~CIPE VARIAP~LES F G H J K
~_ _ _ _ MPDA 1.00 2.00 3.00 2.00 - :
n-Dodecyl mercaptan - - - 1, 5a Pyridine 5~- 5,0 5,0 _ 5~0 POLYMERIZATION ~ESULTS:
Conversion, % 87 80 18 94 92 P'z'n time, hrs. at 70Co 17 17 17 17 7
4-Anilinophenyl-carbamyl0,52 0.76 1.06 - -units incorporated~pOh.r.
Efficiency of ~DA
lncorporation , % 52 38 35 O. R. Values at 90C.92 520 405 500 8.6 a. Added to insure polymer solubllity in benzene.
bo On basis of parts MPDA charged~
INCORPORATION OF OTHER AMINOMERCAPTANS
INTO ISOPRENE/STY~ENE COPOLYMERS B~
~ 20 CHAIN TRANSFER REACTION :~
: Using the general procedure of Example 5, but substituting for MPDA, 2.00 part qwanti~ies o other aminomercaptans characteriæed in Table I, and adjusting for mercaptan activity~ a series of 75.0 isoprene/25.0 styrene mixtures were polymerized or 17 hours at 70 C.
Polymers were isolated, worked up and tested in the manner indicated in Example 5. Parameters relating to poly-merization and to polymer characteris~ics are indicated -31- :
.~ ' '. ., ', ' , ~ ' ' . :
~h'~ 3~
in Table V.
TABIE V
L M N P Q
Aminomercap tan number (~ee Tab1e I IV V VI VIIXIV~
I or II~
Convers1On, % 5~ 53 7S ~9 99 27 P'z'n timea hrs. 22 1& 21 17 17 16 a~ 70C.
OJROa va1ues at 9O~CD 95 420 515 380 245 2~0 aO Charging on1y loOO pt~ of aminomercaptan, O.R. 3 Oxidation-Res~stance: Determined as in Examp1e 6.
INCVRPORA'rION OF AMINOMERCAPTANS I and II INTO BUTADIE~E COPOL~MERS VIA CHAIN
r _~r_ e~ACTlo~
Butadi~ne mixtures wi~h either acrylonitrile or methyl methacrylate weighing 20.0 grams each were polymer-i~ed in four-ounce 6crew~cap bot l~s in presence of 1.60 part amounts of ~minomercaptans as indicated in Table VI~
along wlth control polymers. Rec~pes used contained the reduction-oxidation ("redox") type ini~ia~or sys~eins indlcated in Table VI. Also lncluded in this table are conversion levels of the resul~an~ polymers and ~heir oxldation resictant values after remvval of non~polymeric : substances by extraction.
T~BLE VI
PARTS BY WEIGtlT IN. _ _ INGREDIENTS: T U V W X
~l~tadiene ~7.0 67.0 67.0 8~.0 80.0 Acrylonitrile 33 ~ 0 33 . 0 33 0 0 - -Methyl methacrylate - - - 20.0 20.0 Tetiary dodecyl mercaptan - - 008 - 0.5 MADA (I)a lo~O
MPDA (II)a - 1.60 - 1,60 Potasslum stearate 5.00 5.00 5.00 - -Trlsodium phosphate 0,20 0.20 0.20 Sodium linear alkyl sulfonate - - - 5.00 5.00 Water 200 200 200 200 200 4 7H2 0.042 0.042 0.042 0.042 0.042 ~; Iron chelating agentb 0.17 0.170.17 0.17 0.17 ,odium formaldehyde sulfoxylateO.04 0.04 0.04 0.04 0.04 Cumene hydroperoxide 0.24 0~24 0.24 0.24 0.24 Conversion,% 99 9~ 99 61 9~
~Ro values at 100 C., hours 390 385 1 695 5.9 ~. Adjusted upward for 100~/o mercaptan activity.
b. Active parts of a 34% aqueous solution of a 90/10 mixture of a tetrasodium salt of ethylenediamlne tetracetic acld and the~oao~odlum salt of ~,N-di-(alpha-hydroxyethyl) glycine, sold as 'iVersene Fe III".
-3~-' ~.
- . ~ .
33~-t. 1~) The last two lngreclien~s charged lnto each b)~le were the butadlene and the cumene hydroperoxide.
The bot~les were prechilled to 0C. beEore adding the butadiene 7 swept free oE air by venting the excess of this monomer, and eacll was sealed with a ~crew-cap Lined with self-sealing rubber and Teflon gaskets. The l!ydroperoxide was then added through the cap by use o a hypodermic syringe~ The bottles were then tumbled in a water bath at 10C. for 16 hours. Polymer latices were coagulated into isopropyl alcohol, and the r~sultant coagula freed of non-polymeric ma~erial by repeated - extractions wi~h hot isopropyl alcohol~ The copolymers were evaporated to dryness in vacuum, and tested ~or resistance to oxidation as in EXAMPLE 7, cas~ing nitrile copolymer films from methyl ethyl ketone and the acrylic es~er copolymer films from benzene. In thls instance 9 the oxidation resistance value determination was done at 100 C.
Results, as indicated in Table VI, show that the resis~ance to oxidation of butadiene acrylonitrile copolymers were greatly enhanced relative to a con~rol~
b~ incorporation of antioxidant groups by the use of either aminomercaptan I (MADA) or II (MPDA) and that oxidation resistance of a butadlenelmethyl me~hacrylate copolymer was greatly enhanced over that of a control ~34-: by simi].ar incorpa~i.on of MPDA.
; EXAMPI.E 8 INCORPORATION OF AMINOMERCAPTANS INTO
POLYBUTADIENE ~ ADDITION IN EMULSION
~ A polybutadiene latex was prepared by polymeriz-.~ ing butadiene in an 8-o~ncc screw cap bottle for 16 hours at 50C. using the reclpe lndieated in TABLE VII.
TABLE VII
INGREDIENTS PARTS BY WEIGHT
Butadiene 100 Tertiary dodecyl mercaptan 0.50 K2S28 0.1U
Potassium ~tearate 5.0 : W~ter 200 ~ :
The resultant latex was stripped o res~dual bu~adiene monomer by gently distillingS under ni~rogen atmosphere~ until no oaming occurred and a few droplets of wa~er condensPd~
Two 8~ounce screw-cap bottles were each charged with 72.7 gram quantities of this latex (23.9% solids) containing 20,0 grams of rubber. To each was added 0.25 parts of a~obl~-isobutyronitrile per hundred of rubber ~p.h.r.). One was charged with 2,00 parts o MADA, the other with 2.00 parts of MPDA, both adjusted to 100V/o ~ ~;
mercaptan activity. Bottles were purged with nitrogen, " ' :
sealed an~ tumbled for 16 hours in a water bath a~ 50C.
These latices as well as a sample of untreated polybutadiene latex were coagulated into isopropyl alcohol, ex~racted free of non-polymeric additives, dried and tested for oxidation resistance at 90C~ in ~he manner described ln EXAMPLE 6. On the basis of resn].ts indicated in TABLE VIII, it is seen that a onsiderable degree of lntrinsic oxidation resistance has been incorporat2d into poly-butadiene ~y the use of either MADA or MPDA in ~hls process.
TAB_E VIII
POLYMERS O.R. VALUES AT 90 Polybutadiene control 7.3 Polybutadiene treated with 2.00 parts MADA 6 Polybutadiene treated with 2.00 -~ parts MPDA 58 : EXAMPLE 9 ADDITION OF AMINOMERCAPrANS TO UNSATURATED
HYDROCARSON POLY~CR- I N So~uTloN
. 20 Samples of cis-1.,4-polybutadiene; cis-1,4-poly-: isoprene; and 15 5-polypentenylene, all of which were free :: of antioxidants and of free radical inhibitors were dissolved in benzene and treated with 2.00 parts of an aminomercaptan in presence of azobis-isobutyro~nitile (AIBN) catalyst under nitr~gen atomosphere at 70~C. under ~3~ -~ 3..~7 con~itions indlcated ln Table IX, Polymers were coagulated lnto isopropyl alcoholg freed of non-polymerlc ma~erials and tested for oxidatlon res~stance at 90Ca along wlth control polymers, in the manner described in Example 7 wl~h differen~ amlnomercap~ans identified in Tables I and II~
TABLF, IX
SUBSTRA~E SOLUTION AMINO ~EArT~ON COKDrSl0NS O.R.
MERCAPTAN AIBN TXMEVALUES AT
h~r~ HRSgnoc. HRS
0 ci5-1~4 polybutadienea ~ 9 cls-1,4-polybutadiene MADA 0O40 41 445 cls-lg4-polybu~adlene MPDA 0.20 64 43S
cls-1,4-polybutadieneb IV OD25 64 380 !~
cis-1,4-polybutadlene V 0.~5 64 60 cls-1,4-polybutadiene VI 0.25 64 62 cis-1,4-polybu~adiene VII 0,25 64 62 cis-1,4-polybutadlene x~vf 0.25 64 380 c~s 1~4-polyisopreDe ~ 0~25 cis-1,4-polyisoprene MPDAd 0.25 46 18 : :' 1,5-polypentenylenee --~ 63 1,5 polypentenylenee MPDA 0.40 64 81 a. A 5.00~/O benzene solution of a polymer hav~ng 97%
cis-1j4-structure-b~ A solu~ion o 100 parts of the same polymer in a mixture o~ 295 parts he~ane and 585 parts benzene.
.. . . . . .
t~7 c. A 5.00% benzene solution o~ a polymcr having 96~/~
cis-1,4-structure~
d~ Usin~ 4.00 parts of this compoundO
e~ A 5.00% benzene solution of a polymer made by polymeriz-ing cyclopen~ene with a ~ypical metathesls catalys~O
f. Described in Example 3~
On ~he basis of resul~s indicated in Table IX~ it . mcy be seen that the intrinsic resistance of the polymeric slibstrates were considerably enhanced by interaction wi~h an aminomercaptanO
INCORPORATION OF MPDA INTO BUTADIENE/
STYRENE COPOLYMER DVRING MILLING AND CURING
A commerclal butadiene/styrene copolymer -SBR 150~ (containing 23.5% bound styrene), proteeted with 1.25 parts o~ the non-staining phenolic antioxidant Wingstay T, (product of the Goodyear Tire and Rubber Cnmpany) was compounded on a mill with the ingredients listed in Table X.
TABLE X
INGREDIENTS PARTS BY WEIGHT:
Zlnc ~xide ~5,0 TiO2 30.0 CacO3 24 G ~
Sulfur 2.00 2-Ben~o~hiazolyl, N-morpholinyl disulflde 1,00 MPDA 2~00 , Th~ polymer was pressed into an 0.020 i.nch sheet and cured for 45 minutes at 300F. or to 90 per c~nt of optimum cure based on Monsanto rheometer dataO A con~rol polymer, compounded similarly in absence of MPDA was pressed into a similar sheet which was cured for 30 minutes at 300F. to the same cure level.
A series o one inch strips was cut Erom each whi~e vulcanizateO Some were ex~racted repeatedly with 80¦20 benzene/ethanol mixture at ambient temperature over a 2-week period and then ~ried. Times for extracted strips ~o absorb 1% by wPight o oxygen at 100C. were compared with times required by non-extracted strips. ~ :
~t may be seen on the basis of data recorded ~.
in TABLE XI that whereas the control SBR vulcanizate loses most of its resistance to oxidation by extraction of the antioxidant Wingstay T, that the SBR vulcanizate :.
milled and cured in presence of MPDA retains a very large percentage of its origioal]y higher resistance to .
oxidation aEter extraction beca~se of the chemical incorporation o some of the MPDA into the vulcanizate. ~
TABLE ~I -0.R VALUES AT 100C; HRS
; VULCANIZATE UNEXTRACTED EXTRACTED
SBR - 1502 Control 95 9 :~
SBR - 1502 compounded with MPDA 250 170 - ' Aminomercaptans as conventlonal an~ xldants for butadiene/styrene copolymer.
A butadlerletstyreDe copolymer was preparecl by the method used for preparation of SBR-1()06~ Tlhe latex was shor~stopped at 70% conYersion but was not protected with commerclal antioxidants. The latex was coagulated wi~h isopropyl alcohol 9 . extracted ree of non-polymeric substances with hot ~sopropyl alcohol and vacuum evaporated. A 3% solution of copolymer in benzene was preparedc ~Satches of 'chls eement were charged w~th ~.00 levels of dl:Eer~nt amiTIomercaptans . Oxidat~ on resistance of film~ made rom ~hese cement batches was de~rmlned at 100Co Such values are indicated ln Table XII and compared - with controls. The structureR of the aminorQercaptans are . .
referred to in Table XII by Rs~man nume~als indentified ln Tables I or II.
I~ may be seen from Table XII that all of the aminomercaptans I, IXg~ VII and XIV, when uniormlg 20 distrib~l~ed ln smal:L quantity in SBRa not contalnlng any . ~ other antioxidant, con~iderably enhance the oxidation :: reslstance of this polymer in the ~ame manner that the comEnercial ant~oxidant Wingstay-L does when distrlbuted in the same manner.
: .:
~40~
' .
r~7~
TABLE XII
~b~ 0, R ,, VALIIE S AT
None 0 5 XIV 181) loO() par~ of Wingstay-La 300 - 350 a. A hindered phenol-lc antioxidant product of The Goodyear Tirf~ and ~bber Company.
. Am:1nomercaptans described hereln, some of which are noYel compoundsg serve as an~iox1dants to sta~ilize po1ymers against aging when distr1buted thrc)ughout a polymex by conventional techniques a~ by additi on to a .~ polymer cement or 1atex" by blendlng Into a solid polymer ~:
on a mill or Banbury, or by mixing wi~h a 1iquid polymer or solid polymer powder. Sueh am,nomercaptans inc1ude~
- N (4 ani1 Lno phenyl) ~ mercapto-acetamide, N-Ç4-ani1ino-pheny1)~ mercap~o-prop ionamide, N- ~ , ?' ' dime~hy1-buty1amino)-phenyl~- ~ -merca~o-propionamide and N~ mercapto- ~ "~ di~ethyl-~thyl ~ 3 Nl-pheny1~p~phenglene diam~ne ' ' ' ;~' ~ ' - ~ . ~ . . . ~ .. ...
All o~ he compounds except the first are considered to be new cornpounds. Th~y have antioxidant propPrties. The last of the compounds has some antiozonant propextles as well.
~4~- :
.
Efficiency of ~DA
lncorporation , % 52 38 35 O. R. Values at 90C.92 520 405 500 8.6 a. Added to insure polymer solubllity in benzene.
bo On basis of parts MPDA charged~
INCORPORATION OF OTHER AMINOMERCAPTANS
INTO ISOPRENE/STY~ENE COPOLYMERS B~
~ 20 CHAIN TRANSFER REACTION :~
: Using the general procedure of Example 5, but substituting for MPDA, 2.00 part qwanti~ies o other aminomercaptans characteriæed in Table I, and adjusting for mercaptan activity~ a series of 75.0 isoprene/25.0 styrene mixtures were polymerized or 17 hours at 70 C.
Polymers were isolated, worked up and tested in the manner indicated in Example 5. Parameters relating to poly-merization and to polymer characteris~ics are indicated -31- :
.~ ' '. ., ', ' , ~ ' ' . :
~h'~ 3~
in Table V.
TABIE V
L M N P Q
Aminomercap tan number (~ee Tab1e I IV V VI VIIXIV~
I or II~
Convers1On, % 5~ 53 7S ~9 99 27 P'z'n timea hrs. 22 1& 21 17 17 16 a~ 70C.
OJROa va1ues at 9O~CD 95 420 515 380 245 2~0 aO Charging on1y loOO pt~ of aminomercaptan, O.R. 3 Oxidation-Res~stance: Determined as in Examp1e 6.
INCVRPORA'rION OF AMINOMERCAPTANS I and II INTO BUTADIE~E COPOL~MERS VIA CHAIN
r _~r_ e~ACTlo~
Butadi~ne mixtures wi~h either acrylonitrile or methyl methacrylate weighing 20.0 grams each were polymer-i~ed in four-ounce 6crew~cap bot l~s in presence of 1.60 part amounts of ~minomercaptans as indicated in Table VI~
along wlth control polymers. Rec~pes used contained the reduction-oxidation ("redox") type ini~ia~or sys~eins indlcated in Table VI. Also lncluded in this table are conversion levels of the resul~an~ polymers and ~heir oxldation resictant values after remvval of non~polymeric : substances by extraction.
T~BLE VI
PARTS BY WEIGtlT IN. _ _ INGREDIENTS: T U V W X
~l~tadiene ~7.0 67.0 67.0 8~.0 80.0 Acrylonitrile 33 ~ 0 33 . 0 33 0 0 - -Methyl methacrylate - - - 20.0 20.0 Tetiary dodecyl mercaptan - - 008 - 0.5 MADA (I)a lo~O
MPDA (II)a - 1.60 - 1,60 Potasslum stearate 5.00 5.00 5.00 - -Trlsodium phosphate 0,20 0.20 0.20 Sodium linear alkyl sulfonate - - - 5.00 5.00 Water 200 200 200 200 200 4 7H2 0.042 0.042 0.042 0.042 0.042 ~; Iron chelating agentb 0.17 0.170.17 0.17 0.17 ,odium formaldehyde sulfoxylateO.04 0.04 0.04 0.04 0.04 Cumene hydroperoxide 0.24 0~24 0.24 0.24 0.24 Conversion,% 99 9~ 99 61 9~
~Ro values at 100 C., hours 390 385 1 695 5.9 ~. Adjusted upward for 100~/o mercaptan activity.
b. Active parts of a 34% aqueous solution of a 90/10 mixture of a tetrasodium salt of ethylenediamlne tetracetic acld and the~oao~odlum salt of ~,N-di-(alpha-hydroxyethyl) glycine, sold as 'iVersene Fe III".
-3~-' ~.
- . ~ .
33~-t. 1~) The last two lngreclien~s charged lnto each b)~le were the butadlene and the cumene hydroperoxide.
The bot~les were prechilled to 0C. beEore adding the butadiene 7 swept free oE air by venting the excess of this monomer, and eacll was sealed with a ~crew-cap Lined with self-sealing rubber and Teflon gaskets. The l!ydroperoxide was then added through the cap by use o a hypodermic syringe~ The bottles were then tumbled in a water bath at 10C. for 16 hours. Polymer latices were coagulated into isopropyl alcohol, and the r~sultant coagula freed of non-polymeric ma~erial by repeated - extractions wi~h hot isopropyl alcohol~ The copolymers were evaporated to dryness in vacuum, and tested ~or resistance to oxidation as in EXAMPLE 7, cas~ing nitrile copolymer films from methyl ethyl ketone and the acrylic es~er copolymer films from benzene. In thls instance 9 the oxidation resistance value determination was done at 100 C.
Results, as indicated in Table VI, show that the resis~ance to oxidation of butadiene acrylonitrile copolymers were greatly enhanced relative to a con~rol~
b~ incorporation of antioxidant groups by the use of either aminomercaptan I (MADA) or II (MPDA) and that oxidation resistance of a butadlenelmethyl me~hacrylate copolymer was greatly enhanced over that of a control ~34-: by simi].ar incorpa~i.on of MPDA.
; EXAMPI.E 8 INCORPORATION OF AMINOMERCAPTANS INTO
POLYBUTADIENE ~ ADDITION IN EMULSION
~ A polybutadiene latex was prepared by polymeriz-.~ ing butadiene in an 8-o~ncc screw cap bottle for 16 hours at 50C. using the reclpe lndieated in TABLE VII.
TABLE VII
INGREDIENTS PARTS BY WEIGHT
Butadiene 100 Tertiary dodecyl mercaptan 0.50 K2S28 0.1U
Potassium ~tearate 5.0 : W~ter 200 ~ :
The resultant latex was stripped o res~dual bu~adiene monomer by gently distillingS under ni~rogen atmosphere~ until no oaming occurred and a few droplets of wa~er condensPd~
Two 8~ounce screw-cap bottles were each charged with 72.7 gram quantities of this latex (23.9% solids) containing 20,0 grams of rubber. To each was added 0.25 parts of a~obl~-isobutyronitrile per hundred of rubber ~p.h.r.). One was charged with 2,00 parts o MADA, the other with 2.00 parts of MPDA, both adjusted to 100V/o ~ ~;
mercaptan activity. Bottles were purged with nitrogen, " ' :
sealed an~ tumbled for 16 hours in a water bath a~ 50C.
These latices as well as a sample of untreated polybutadiene latex were coagulated into isopropyl alcohol, ex~racted free of non-polymeric additives, dried and tested for oxidation resistance at 90C~ in ~he manner described ln EXAMPLE 6. On the basis of resn].ts indicated in TABLE VIII, it is seen that a onsiderable degree of lntrinsic oxidation resistance has been incorporat2d into poly-butadiene ~y the use of either MADA or MPDA in ~hls process.
TAB_E VIII
POLYMERS O.R. VALUES AT 90 Polybutadiene control 7.3 Polybutadiene treated with 2.00 parts MADA 6 Polybutadiene treated with 2.00 -~ parts MPDA 58 : EXAMPLE 9 ADDITION OF AMINOMERCAPrANS TO UNSATURATED
HYDROCARSON POLY~CR- I N So~uTloN
. 20 Samples of cis-1.,4-polybutadiene; cis-1,4-poly-: isoprene; and 15 5-polypentenylene, all of which were free :: of antioxidants and of free radical inhibitors were dissolved in benzene and treated with 2.00 parts of an aminomercaptan in presence of azobis-isobutyro~nitile (AIBN) catalyst under nitr~gen atomosphere at 70~C. under ~3~ -~ 3..~7 con~itions indlcated ln Table IX, Polymers were coagulated lnto isopropyl alcoholg freed of non-polymerlc ma~erials and tested for oxidatlon res~stance at 90Ca along wlth control polymers, in the manner described in Example 7 wl~h differen~ amlnomercap~ans identified in Tables I and II~
TABLF, IX
SUBSTRA~E SOLUTION AMINO ~EArT~ON COKDrSl0NS O.R.
MERCAPTAN AIBN TXMEVALUES AT
h~r~ HRSgnoc. HRS
0 ci5-1~4 polybutadienea ~ 9 cls-1,4-polybutadiene MADA 0O40 41 445 cls-lg4-polybu~adlene MPDA 0.20 64 43S
cls-1,4-polybutadieneb IV OD25 64 380 !~
cis-1,4-polybutadlene V 0.~5 64 60 cls-1,4-polybutadiene VI 0.25 64 62 cis-1,4-polybu~adiene VII 0,25 64 62 cis-1,4-polybutadlene x~vf 0.25 64 380 c~s 1~4-polyisopreDe ~ 0~25 cis-1,4-polyisoprene MPDAd 0.25 46 18 : :' 1,5-polypentenylenee --~ 63 1,5 polypentenylenee MPDA 0.40 64 81 a. A 5.00~/O benzene solution of a polymer hav~ng 97%
cis-1j4-structure-b~ A solu~ion o 100 parts of the same polymer in a mixture o~ 295 parts he~ane and 585 parts benzene.
.. . . . . .
t~7 c. A 5.00% benzene solution o~ a polymcr having 96~/~
cis-1,4-structure~
d~ Usin~ 4.00 parts of this compoundO
e~ A 5.00% benzene solution of a polymer made by polymeriz-ing cyclopen~ene with a ~ypical metathesls catalys~O
f. Described in Example 3~
On ~he basis of resul~s indicated in Table IX~ it . mcy be seen that the intrinsic resistance of the polymeric slibstrates were considerably enhanced by interaction wi~h an aminomercaptanO
INCORPORATION OF MPDA INTO BUTADIENE/
STYRENE COPOLYMER DVRING MILLING AND CURING
A commerclal butadiene/styrene copolymer -SBR 150~ (containing 23.5% bound styrene), proteeted with 1.25 parts o~ the non-staining phenolic antioxidant Wingstay T, (product of the Goodyear Tire and Rubber Cnmpany) was compounded on a mill with the ingredients listed in Table X.
TABLE X
INGREDIENTS PARTS BY WEIGHT:
Zlnc ~xide ~5,0 TiO2 30.0 CacO3 24 G ~
Sulfur 2.00 2-Ben~o~hiazolyl, N-morpholinyl disulflde 1,00 MPDA 2~00 , Th~ polymer was pressed into an 0.020 i.nch sheet and cured for 45 minutes at 300F. or to 90 per c~nt of optimum cure based on Monsanto rheometer dataO A con~rol polymer, compounded similarly in absence of MPDA was pressed into a similar sheet which was cured for 30 minutes at 300F. to the same cure level.
A series o one inch strips was cut Erom each whi~e vulcanizateO Some were ex~racted repeatedly with 80¦20 benzene/ethanol mixture at ambient temperature over a 2-week period and then ~ried. Times for extracted strips ~o absorb 1% by wPight o oxygen at 100C. were compared with times required by non-extracted strips. ~ :
~t may be seen on the basis of data recorded ~.
in TABLE XI that whereas the control SBR vulcanizate loses most of its resistance to oxidation by extraction of the antioxidant Wingstay T, that the SBR vulcanizate :.
milled and cured in presence of MPDA retains a very large percentage of its origioal]y higher resistance to .
oxidation aEter extraction beca~se of the chemical incorporation o some of the MPDA into the vulcanizate. ~
TABLE ~I -0.R VALUES AT 100C; HRS
; VULCANIZATE UNEXTRACTED EXTRACTED
SBR - 1502 Control 95 9 :~
SBR - 1502 compounded with MPDA 250 170 - ' Aminomercaptans as conventlonal an~ xldants for butadiene/styrene copolymer.
A butadlerletstyreDe copolymer was preparecl by the method used for preparation of SBR-1()06~ Tlhe latex was shor~stopped at 70% conYersion but was not protected with commerclal antioxidants. The latex was coagulated wi~h isopropyl alcohol 9 . extracted ree of non-polymeric substances with hot ~sopropyl alcohol and vacuum evaporated. A 3% solution of copolymer in benzene was preparedc ~Satches of 'chls eement were charged w~th ~.00 levels of dl:Eer~nt amiTIomercaptans . Oxidat~ on resistance of film~ made rom ~hese cement batches was de~rmlned at 100Co Such values are indicated ln Table XII and compared - with controls. The structureR of the aminorQercaptans are . .
referred to in Table XII by Rs~man nume~als indentified ln Tables I or II.
I~ may be seen from Table XII that all of the aminomercaptans I, IXg~ VII and XIV, when uniormlg 20 distrib~l~ed ln smal:L quantity in SBRa not contalnlng any . ~ other antioxidant, con~iderably enhance the oxidation :: reslstance of this polymer in the ~ame manner that the comEnercial ant~oxidant Wingstay-L does when distrlbuted in the same manner.
: .:
~40~
' .
r~7~
TABLE XII
~b~ 0, R ,, VALIIE S AT
None 0 5 XIV 181) loO() par~ of Wingstay-La 300 - 350 a. A hindered phenol-lc antioxidant product of The Goodyear Tirf~ and ~bber Company.
. Am:1nomercaptans described hereln, some of which are noYel compoundsg serve as an~iox1dants to sta~ilize po1ymers against aging when distr1buted thrc)ughout a polymex by conventional techniques a~ by additi on to a .~ polymer cement or 1atex" by blendlng Into a solid polymer ~:
on a mill or Banbury, or by mixing wi~h a 1iquid polymer or solid polymer powder. Sueh am,nomercaptans inc1ude~
- N (4 ani1 Lno phenyl) ~ mercapto-acetamide, N-Ç4-ani1ino-pheny1)~ mercap~o-prop ionamide, N- ~ , ?' ' dime~hy1-buty1amino)-phenyl~- ~ -merca~o-propionamide and N~ mercapto- ~ "~ di~ethyl-~thyl ~ 3 Nl-pheny1~p~phenglene diam~ne ' ' ' ;~' ~ ' - ~ . ~ . . . ~ .. ...
All o~ he compounds except the first are considered to be new cornpounds. Th~y have antioxidant propPrties. The last of the compounds has some antiozonant propextles as well.
~4~- :
.
Claims (11)
1. A polymer consisting of segmeric units from the class consisting of (1) conjugated diene monomers of 4 to 10 carbon atoms and (2) non-conjugated cyclic or acylic olefin monomers of 2 to 20 carbon atoms and (3) vinyl monomers of 2 to 10 carbon atoms and (4) any combination thereof, to which is attached one or more units of an age-resisting group of the formula in which R = a radical of the class consisting of (a) phenyl and phenyl which is substi-tuted in any one or more positions with an alkyl or alkoxy group of 1 to 4 carbon atoms or with a radical of the formula in which both R7 and R8 are either an alkyl group of 1 to 4 carbon atoms or hydrogen; and (b) a cycloalkyl radical having from 5 to 12 carbon atoms; and (c) a branched acyclic group comprising a chain of 1 to 12 carbon atoms, and each carbon may be substituted with 1 to 2 alkyl groups of 1 to 3 carbon atoms; and (d) an alicyclic aralkyl or aryl radical having from 7 to 14 carbon atoms.
m = zero or 1 n = 0 to 12 R1, R2, R3, R4, R5, and R6 are each selected from the group consisting of hydrogen and alkyl groups of 1 to 5 carbon atoms; and may be the same or different, the attachment being through the sulfur linkage, the age-resisting portion of the polymer being 1.1 to 10 parts per 100 parts by weight of the polymer and being attached to the body of the polymer either at a terminal or side chain portion; the polymer portion attached to the age-resisting group or groups being a homopolymer or copolymer and being isotactic, syndiotactic or atactic.
m = zero or 1 n = 0 to 12 R1, R2, R3, R4, R5, and R6 are each selected from the group consisting of hydrogen and alkyl groups of 1 to 5 carbon atoms; and may be the same or different, the attachment being through the sulfur linkage, the age-resisting portion of the polymer being 1.1 to 10 parts per 100 parts by weight of the polymer and being attached to the body of the polymer either at a terminal or side chain portion; the polymer portion attached to the age-resisting group or groups being a homopolymer or copolymer and being isotactic, syndiotactic or atactic.
2. Compounds of claim 1 in which a substantial portion of the monomer segmers include those of butadiene-1,3 or isoprene.
3. Compounds of claim 2 in which at least one age-resisting group is p-anilino-phenyl-carbamyl-methyl sulfide or beta-(p-anilino-phenyl-carbamyl)-ethyl sulfide.
4. The process of producing a polymer self-resistant to aging, by a chain transfer reaction which comprises homopolymerizing or copolymerizing by a free radical process involving a chain transfer reaction, olefinic and diolefinic monomers of 2 to 10 carbon atoms of the class consisting of 1,3-diolefins and vinyl monomers in the presence of from 0.1 to 10 parts by weight per 100 parts of monomer of an aminomercaptan whose structure is defined by the formula in which R = a radical of the class consisting of (a) phenyl and phenyl which is substi-tuted in any one or more positions with an alkyl or alkoxy group of 1 to 4 carbon atoms or with a radical of the formula in which both R7 and R8 are either an alkyl group of 1 to 4 carbon atoms or hydrogen; and (b) a cycloalkyl radical having from 5 to 12 carbon atoms; and (c) a branched acyclic group comprising a chain of 1 to 12 carbon atoms, and each carbon may be substituted with 1 to 2 alkyl groups of 1 to 3 carbon atoms; and (d) an alicyclic aralkyl or aryl radical having from 7 to 14 carbon atoms.
m = zero or 1 n = 0 to 12 R1, R2, R3, R4, R5, and R6 are each selected from the group consisting of hydrogen and alkyl groups of 1 to 5 carbon atoms; and may be the same or different.
m = zero or 1 n = 0 to 12 R1, R2, R3, R4, R5, and R6 are each selected from the group consisting of hydrogen and alkyl groups of 1 to 5 carbon atoms; and may be the same or different.
5. The process of claim 4 in which the aminomercaptan is either N-(4-anilino-phenyl)-?-mercapto-acetamide or N-(4-anilino-phenyl)-.beta.-mercapto-propionamide and substantial portion of the monomer used is butadiene-1,3 or isoprene or a vinyl copolymer thereof.
6. The process of producing a polymer self-resistant to aging by an addition reaction) which process comprises interacting a polymeric substrate containing at least one reactable double bond per polymer molecule with from 0.1 to 10 parts by weight of an aminomercaptan of the formula in which R = a radical of the class consisting of (a) phenyl and phenyl which is substi-tuted in any one or more positions with an alkyl or alkoxy group of 1 to 4 carbon atoms or with a radical of the formula in which both R7 and R8 are either an alkyl group of 1 to 4 carbon atoms or hydrogen; and (b) a cycloalkyl radical having from 5 to 12 carbon atoms; and (c) a branched acyclic group comprising a chain of 1 to 12 carbon atoms, and each carbon may be substituted with 1 to 2 alkyl groups of 1 to 3 carbon atoms; and (d) an alicyclic aralkyl or aryl radical having from 7 to 14 carbon atoms.
m = zero or 1 n = 0 to 12 R1, R2, R3, R4, R5, and R6 are each selected from the group consisting of hydrogen and alkyl groups of 1 to 5 carbon atoms; and may be the same or different, in the presence of a free radical catalyst.
m = zero or 1 n = 0 to 12 R1, R2, R3, R4, R5, and R6 are each selected from the group consisting of hydrogen and alkyl groups of 1 to 5 carbon atoms; and may be the same or different, in the presence of a free radical catalyst.
7. The process of claim 6 in which the aminomercaptan is from the class consisting of N-(4-anilino-phenyl)-?-mercapto-acetamide and N-(4-anilino-phenyl)-.beta.-mercapto-acetamide and a substantial portion of the monomer used is butadiene-1,3 or isoprene or a vinyl comonomer thereof.
8. The process of producing a polymer self-resistant to aging which comprises mixing with a millable elastomeric diene polymer or copolymer plus a curing agent, 0.1 to 10 parts by weight per 100 parts of said polymer or copolymer, of a aminomercaptan, and then curing; the aminomercaptan having the formula in which R = a radical of the class consisting of (a) phenyl and phenyl which is substi-tuted in any one or more positions with an alkyl or alkoxy group of 1 to 4 carbon atoms or with a radical of the formula in which both R7 and R8 are either an alkyl group of 1 to 4 carbon atoms or hydrogen; and (b) a cycloalkyl radical having from 5 to 12 carbon atoms; and (c) a branched acyclic group comprising a chain of 1 to 12 carbon atoms, and each carbon may be substituted with 1 to 2 alkyl groups of 1 to 3 carbon atoms; and (d) an alicyclic aralkyl or aryl radical having from 7 to 14 carbon atoms, m = zero or 1 n = 0 to 12 R1, R2, R3, R4, R5 and R6 are each selected from the group consisting of hydrogen and alkyl group s of 1 to 5 carbon atoms; and may be the same or different.
9. The process of claim 8 in which the copolymer is butadiene styrene.
10. The process of claim 8 in which the homopolymer is polybutadiene or polyisoprene.
11. The process of claim 8 in which the aminomercaptan is from the class consisting of N-(anillno-phenyl)-?-mercapto-acetamide and N-(4-anilino-phenyl)- .beta. -mercapto-propionamide.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US71255176A | 1976-08-09 | 1976-08-09 | |
| US712,551 | 1976-08-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1108347A true CA1108347A (en) | 1981-09-01 |
Family
ID=24862594
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA282,763A Expired CA1108347A (en) | 1976-08-09 | 1977-07-14 | Age-resisting polymers and their preparation by reactions involving use of certain aminomercaptans |
Country Status (10)
| Country | Link |
|---|---|
| JP (2) | JPS5321290A (en) |
| BE (1) | BE857591A (en) |
| BR (1) | BR7705182A (en) |
| CA (1) | CA1108347A (en) |
| DE (1) | DE2735178C2 (en) |
| FR (1) | FR2361424A1 (en) |
| GB (1) | GB1536253A (en) |
| IT (1) | IT1079406B (en) |
| NL (1) | NL181016C (en) |
| ZA (1) | ZA774041B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2540495B1 (en) * | 1983-02-07 | 1986-02-14 | Roussel Uclaf | NOVEL DERIVATIVES OF O-MERCAPTOPROPANAMIDE AND ITS HOMOLOGUES, THEIR PREPARATION METHOD, THEIR APPLICATION AS MEDICAMENTS, THE COMPOSITIONS CONTAINING THEM AND THE NEW INTERMEDIATES OBTAINED |
| DE3324194A1 (en) * | 1983-07-05 | 1985-01-17 | Bayer Ag, 5090 Leverkusen | AGING AGENTS, THEIR PRODUCTION AND THEIR POLYMERS CONTAINING THEM |
| DE3430510A1 (en) * | 1984-08-18 | 1986-02-27 | Bayer Ag, 5090 Leverkusen | AGING AGENTS AND POLYMERS CONTAINING THEM |
| AU2001234056B2 (en) * | 2001-01-04 | 2007-11-01 | Council Of Scientific And Industrial Research | A new linker based solid support for peptide and small molecule organic synthesis |
| FR2854404B1 (en) | 2003-04-29 | 2005-07-01 | Michelin Soc Tech | METHOD OF OBTAINING GRAFT ELASTOMER WITH FUNCTIONAL GROUPS ALONG THE CHAIN AND RUBBER COMPOSITIONS |
| JP4934323B2 (en) * | 2006-02-07 | 2012-05-16 | 株式会社ブリヂストン | Modified natural rubber, process for producing the same, rubber composition and tire using the same |
| JP5265093B2 (en) * | 2006-05-19 | 2013-08-14 | 株式会社ブリヂストン | Rubber composition and tire using the same |
| EP3191528B1 (en) * | 2014-09-12 | 2021-12-29 | Cooper Tire & Rubber Company | Oxidation resistant natural rubber and a method for its production |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1278526A (en) * | 1970-02-24 | 1972-06-21 | Winner Food Products Ltd | Continuous preparation of pastry |
| GB1441621A (en) * | 1973-07-13 | 1976-07-07 | Ici Ltd | Sulphides |
| JPS6039684B2 (en) * | 1974-03-06 | 1985-09-07 | スコツト ジエラルド | Method for producing oxidatively stable polymers |
-
1977
- 1977-07-05 ZA ZA00774041A patent/ZA774041B/en unknown
- 1977-07-14 CA CA282,763A patent/CA1108347A/en not_active Expired
- 1977-07-26 GB GB31312/77A patent/GB1536253A/en not_active Expired
- 1977-07-28 IT IT50491/77A patent/IT1079406B/en active
- 1977-08-04 DE DE2735178A patent/DE2735178C2/en not_active Expired
- 1977-08-04 FR FR7724047A patent/FR2361424A1/en active Granted
- 1977-08-05 BR BR7705182A patent/BR7705182A/en unknown
- 1977-08-08 BE BE180000A patent/BE857591A/en not_active IP Right Cessation
- 1977-08-09 JP JP9550777A patent/JPS5321290A/en active Granted
- 1977-08-09 NL NLAANVRAGE7708787,A patent/NL181016C/en not_active IP Right Cessation
-
1987
- 1987-01-05 JP JP62000330A patent/JPS62253639A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0219142B2 (en) | 1990-04-27 |
| BR7705182A (en) | 1978-05-30 |
| DE2735178C2 (en) | 1985-05-23 |
| NL181016C (en) | 1987-06-01 |
| JPS6330326B2 (en) | 1988-06-17 |
| DE2735178A1 (en) | 1978-02-16 |
| FR2361424A1 (en) | 1978-03-10 |
| IT1079406B (en) | 1985-05-13 |
| BE857591A (en) | 1977-12-01 |
| FR2361424B1 (en) | 1980-04-25 |
| NL7708787A (en) | 1978-02-13 |
| ZA774041B (en) | 1978-05-30 |
| JPS5321290A (en) | 1978-02-27 |
| JPS62253639A (en) | 1987-11-05 |
| GB1536253A (en) | 1978-12-20 |
| NL181016B (en) | 1987-01-02 |
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