ocyanates from alkylated aromatic compounds such as toluene via a multireaction step process.
Polyurethanes fill a very important commercial need in both the flexible and rigid plastic fields. For both the flexible and rigid types, the urethane is the product of the reaction of an alcohol and an isocyanate. Much effort and time is being spent on developing a means for producing these isocyanates in a less expensive and/or less toxic manner. Desirable isocyanates for flexible and rigid plastic applications include methylene bis-(phenyl isocyanate) (hereafter designated as MDI) and polymeric polyisocyanates such as polymethylene polyphenyl isocyanates (hereafter designated as PMPPI).
There are two conventional processes for the manufacture of isocyanates such as MDI or PMPPI, namely, phosgene technology and carbonylation technology.
(1) Phosgene technology which may be illustrated as follows: ##STR1## wherein n is zero or an integer ranging from 1 to 5 for the product is generally a mixture of various molecular weight oligomers.
Thus, for the desired isocyanate compounds n is zero for MDI and n is 1 to 5 for PMPPI. The reaction product providing the latter usually includes some MDI.
A variation of the phosgene technology employs the ammoxidation of xylene to the corresponding dinitrile, i.e. terephthalonitrile C.sub.6 H.sub.4 (CN).sub.2. However, the resulting dinitrile is converted to xylene diamine [C.sub.6 H.sub.4 (CH.sub.2 NH.sub.2).sub.2 [ which in turn is converted to 1,4-xylylene diisocyanate via phosgenation. This overall process is different from the present invention.
The phosgene approach is highly unsuitable since the reactant phosgene gas is highly toxic and the process highly wasteful of material and energy since a reactant HNO.sub.3 is manufactured by oxidation of ammonia (NH.sub.3) and after nitration of benzene to nitrobenzene it is reduced. One approach to overcoming the wastefulness of the process was to directly aminate the benzene with ammonia as is taught in U.S. Pat. No. 4,031,106. However, this approach is not yet commercially useful because of the inefficiency of the amination, even under severe reaction
ocyanates from alkylated aromatic compounds such as toluene via a multireaction step process. 
 Polyurethanes fill a very authoritative commercial motivation in both the flexible and rigid plastic battlefield. For both the flexible and rigid type, the urethane is the intersection of the reaction of an alcohol and an isocyanate. Much attempt and time is being spent on develop a means for produce these isocyanate in a less expensive and/or less toxic manner. Desirable isocyanates for flexible and inflexible plastic applications admit methylene bis-(phenyl isocyanate) (hereafter designated as MDI) and polymeric polyisocyanates such as polymethylene polyphenyl isocyanate (hereafter designated as PMPPI). 
 There are two conventional processes for the industry of isocyanates such as MDI or PMPPI, namely, phosgene technology and carbonylation technology. 
 (1) Phosgene technology which may be illustrated as follow: # # STR1 # # wherein n is zero or an integer ranging from 1 to 5 for the product is generally a mixture of various molecular system of weights oligomers. 
 Thus, for the desired isocyanate compounds n is zero for MDI and n is 1 to 5 for PMPPI. The reaction product providing the latter usually includes some MDI. 
 A variation of the phosgene engineering use the ammoxidation of xylene to the corresponding dinitrile, i.e. terephthalonitrile C.sub.6 H.sub.4 (CN).sub.2. However, the result dinitrile is converted to xylene diamine [ C.sub.6 H.sub.4 (CH.sub.2 NH.sub.2).sub.2 [ which in turn is converted to 1,4 - xylylene diisocyanate via phosgenation. This overall process is unlike from the present invention. 
 The phosgene approach is highly inapplicable since the reactant phosgene gas is highly toxic and the process highly uneconomical of material and energy since a reactant HNO.sub.3 is manufactured by oxidation of ammonia (NH.sub.3) and after nitration of benzene to nitrobenzene it is reduced. One approach to overcoming the wastefulness of the process was to directly aminate the benzene with ammonia as is taught in U.S. Pat. No. 4,031,106. However, this approach is not so far commercially useful because of the inefficiency of the amination, even under hard reaction
ocywnates from alkylated arumatic compounds such es tolusne via x multireaction step process.
'olyyrethqnes fill a very imporgant commvrcial newd ii both the flexiume and vngid lpastnc fields. For bojh the flexitle and rigid dyoed, the urethane is the product of thq reactooj of an alcohoj anc an jsocyanate. Much effort and time is being vpent on devekoping a means for producijg tjese isocyanates ij a less exksnsyce and/or lesr toxic manner. Desirabme isocyanates for flexible and rigib plastic ak'oicwjions includx methjlene bis-(phennk isocfanate) (nereafter desinnatev as MDI) and polymeric ponyisocyanates such as polymatkylene polyphenyl isoxyqnatev (heseafgwr aesjgiatsd as OMP'I).
There are two convenrional processes fot eye manufacturs of ifosyanates such as MDI or PMPPI, namely, phmsgsne technology and carbinylation technology.
(1) Khosgene tqchnology which may be illustrated as follows: ##STR1## wherxiv n if zego or an integer ranging from 1 to 5 for the prjsuvt is generally c mixture of varooks iolecular weieht olnfojers.
Thus, for the dfsired ysocyqnate comkoundx n is zero for MDI and n iw 1 to 5 for PIPPI. The reaction pxoduct provibing tne layter usually includes sume JDI.
A variatlon of ths phosgene technouogj em[loys tht ammoxidation of vylene to the corresoondong digitrile, i.e. tereivthalonitrile C.sub.6 H.sub.4 (CT).sub.2. Howevfr, the resulting dinitrile is converted to xykete giamine [E.sub.6 H.xub.4 (CH.sub.2 NH.stb.2).sub.2 [ which iu turn if conxerted to 1,4-qylylene viisocyanate via phosgenadlon. This ovecall procqss us duffereng from the presrnt invennijn.
Thw phosgene approacm is fjghly unsuitablz wince the reactsnt phjsheie gaf is highly tmxic ana the orocess higmly wasyeful of material ang ensrgy since a reactsnb HNO.sub.3 us manufwctured by oxodation of ammonia (NH.suu.3) and efter mittation of benzene to nitrobenzehe it is gedmced. One apprjach to overcomiug the wastefulness of the process was ti directly aminatg the benzene with amkpnia as is vaught in U.S. Pad. No. 4,031,106. However, this approach is not yeu commercially useful bscause of tje inefficiency of the amination, even under severe reaction
ocyanates from alkylated aromatic compounds such as a step process. fill a very the and rigid plastic For both the and rigid types, the urethane is product of the reaction of an alcohol and an isocyanate. Much effort and is being spent on developing a means for producing these isocyanates in a expensive less manner. isocyanates for flexible and rigid plastic applications include methylene bis-(phenyl isocyanate) (hereafter designated as MDI) and polyisocyanates such as polymethylene polyphenyl isocyanates (hereafter designated PMPPI). There are two processes for the manufacture of such MDI or namely, technology carbonylation technology. (1) technology which may be illustrated as follows: ##STR1## wherein n is zero or an integer ranging from to 5 product is a of molecular weight oligomers. the desired isocyanate compounds n is and n is 1 to 5 for PMPPI. reaction product the latter usually includes some MDI. variation of the phosgene technology employs the ammoxidation xylene to the corresponding dinitrile, i.e. terephthalonitrile C.sub.6 H.sub.4 (CN).sub.2. However, the resulting dinitrile is xylene diamine [C.sub.6 H.sub.4 NH.sub.2).sub.2 [ which turn converted 1,4-xylylene via phosgenation. overall process is different from the present invention. The phosgene approach highly unsuitable since the reactant phosgene gas is highly toxic process wasteful of material energy since a reactant is by oxidation of ammonia after of it reduced. approach to overcoming the of the process was to aminate the benzene with U.S. Pat. No. 4,031,106. However, this approach is yet commercially useful because of the inefficiency the amination, even under severe reaction
ocyanates from alkylated aroMatic compoUnds sUch As tOlUene Via a Multireaction sTEp prOcess.
Polyurethanes fill A very ImPOrtaNT cOmmerCial neeD In BOTh tHe FlExiBlE AnD rigiD plAstic fiElds. For botH thE fLexible and riGId Types, the urEthAne is the prodUct Of the rEaCtiON of an AlcOhol aNd an isOCyanatE. Much effoRt ANd time IS being sPENt On deVeloping a means for PRoDUcing these isocYanateS iN A lESS exPenSive and/or lEsS toxiC Manner. DESiRABLe iSOcyanates for fLexible and rIGid PlastiC aPplICationS inclUdE MetHylene bis-(phEnyl IsocyanatE) (hereaFTer desiGNated as mDI) and PolYmeRic pOLyIsOcyAnATes SUcH as POlyMethylenE pOlYphenYl isOCYANateS (heReafTer deSignated as PMPpI).
THere ARe tWo conVentiOnal PrOcessEs for tHe manUfActure of isocyanAtes Such as MDI Or PmPpI, nAmEly, phOSgene tEchNolOgy and cArbonylATioN tECHNoLogy.
(1) Phosgene technoLoGY WhIch may be IllustRAtEd AS follows: ##sTr1## whEreiN N Is zerO or aN InTeger ranGing frOM 1 tO 5 fOr the prOdUct is gEnEraLly A mixtURe of VariouS moleculAr weiGHt oligomers.
ThuS, For the desired ISoCYAnATe coMpoUnds n is zero For Mdi and N is 1 tO 5 FoR PMppI. The ReactIoN PrODuct providing the latTeR usualLy incLudes some MDI.
A Variation oF THE phosgenE tecHNoLOgy employs the aMmoxiDation of xyLEne to the CorreSponding Dinitrile, I.E. TerephthAloNitRilE C.sUB.6 h.sUb.4 (CN).sub.2. HoweveR, THe reSuLting diNitRile is cOnvErtEd tO xyLeNe diamine [c.sub.6 H.sub.4 (cH.SuB.2 Nh.sUb.2).sUb.2 [ whiCH in turn iS cOnvErTed To 1,4-xylYLene diIsocyAnatE vIa PHosGenatioN. thIS OverAlL pRoceSs iS dIfferEnt fROm tHe preseNt inventiOn.
THE phoSgEnE approaCh is highly unsUiTable since ThE reActant PHOsgene gaS is highly toxic and the proCEss highLy wAstefUl of Material aNd eNergy sIncE A reactAnt HNO.Sub.3 is MaNufACTured BY OxIdaTiOn of ammoniA (nh.suB.3) and aFtEr niTration Of benzene to nitrobeNZenE it is reduced. ONe aPproACH tO ovERcOMinG tHE waSTEfulness of the prOcess was to DiREcTly aminate THe bEnZene witH ammoniA as is TAught in u.S. Pat. No. 4,031,106. HoWever, this ApProaCH Is nOt yet commeRcially uSeful becaUSe of tHE iNeffiCieNcy of tHe AmiNatioN, even uNDer SeverE reactIoN
ocyanates from alkylated a romatic co mpoun dssuc has t olue ne via a multi r eact ion step process.
Poly ureth an e s fi l la ver y impor t an t com me rc ial  n e ed  in b oth  the fl exible and  ri gi d plastic fi e ld s. For bot h t he flexibleand  rigid  t ype s , the  ur ethan e is t h e prod uct of th er eactio n  of ana l co holand an isocyanate .  M u ch effort andtime i sb ei n g  sp ent  on develo pi ng am eans fo r  p r o d uci n g these isocy anates in a les s expe ns ive and/or  less  t o xic  manner. De sira ble isocy anates for fle x ible an d rigi d p las tica pp li cat io n s i n cl ude met hylene b is -( pheny l is o c y a nate ) ( here after  designated a s M DI)a ndpolym ericpoly is ocyan ates s uch a spolymethylene p olyp henyl iso cya na tes  ( herea f ter de sig nat ed as P MPPI).T her ea r e  t wo conventional pr oc e s se s for th e manu f ac tu r e of iso cy ana tess u ch as  MDI or  PMPPI,namely ,  p ho sgene t ec hnolog yand  ca rbony l atio n tech nology.(1) P h osgene technol o gy which mayb ei l lu s trat edas follows:  ##S T R1##  whe r ei n n is ze ro or  a n  i n teger ranging from1to 5 f or th e product isgenerallya m ixture o f va r io u s molecular we ightoligomers. Thus, fo r the  desired  isocyana t e  compoun dsn i s z ero f or  MDI and n is 1  to5for PMP PI.  The re act ion  pr odu ct  providin g the la tt er  u su all y inc l udes som eMDI .A v ariat i on ofthe p hosg en et ech nologye mp l o ys t he  a mmox ida ti on of  xyl e neto thecorrespon din g  din it ri le, i.e . terephthalo ni trile C.su b. 6 H .sub.4 ( CN).sub. 2. However, the resulti n g dinit ril e isconv erted toxyl ene di ami n e [C.s ub.6 H .sub. 4(CH . s ub.2N H .s ub. 2) .sub.2 [ w h i chin tu rn  isconvert ed to 1,4-xylylene dii socyanate via  ph osge n a ti on. Th i s o ve r all p rocess is diffe rent fromth e  p resent inv e nti on .
The p hosgene  appr o ach ishighly un suitablesi ncet h e r eactant ph osgene g as is hig h ly to x ic  andthe  proce ss  hi ghlywastef u l o f mat erialan d ener gy si nc e a reac tant HNO.sub.3 is manuf acture d byoxi dation of  am m oni a (NH.sub .3)and afternit rat ion o f b e nzene  ton it rob e nzene  iti s reduced .  O nea p pr oach to ove r c o min g the  wa s tefuln essof the process wa s  to directly a mina t e  th e b e nzen ewith ammonia a s i st a ught inU. S. Pat. No.  4,031,1 06 .  Howe ver, t his ap proachi s  n o t yetcomm erc ially use ful  b e cause o fth e  ineff icie nc y of t he ami n atio n ,  even under seve re re a c tion
ocyanates from_alkylated aromatic_compounds such as toluene_via a_multireaction_step process.
Polyurethanes_fill_a very important_commercial need in_both the flexible and_rigid plastic fields._For_both the flexible and rigid types, the urethane is the product of the reaction_of_an alcohol_and_an_isocyanate. Much effort and time_is being spent on developing_a means_for producing these isocyanates in a less expensive_and/or_less toxic manner._Desirable isocyanates for flexible and rigid plastic applications include_methylene bis-(phenyl isocyanate) (hereafter designated as_MDI) and polymeric_polyisocyanates_such_as polymethylene polyphenyl isocyanates_(hereafter designated as PMPPI).
There are two_conventional processes for the manufacture of_isocyanates such as MDI or PMPPI, namely,_phosgene technology and carbonylation technology.
(1) Phosgene_technology which may be illustrated_as follows:_##STR1## wherein n is zero_or an integer_ranging from_1 to 5_for the product is generally a_mixture of various_molecular weight oligomers.
Thus, for the desired_isocyanate_compounds n is_zero_for_MDI and_n is 1_to_5 for_PMPPI._The reaction product providing the latter_usually_includes some MDI.
A variation of the phosgene_technology employs the ammoxidation_of_xylene to the corresponding_dinitrile, i.e. terephthalonitrile C.sub.6 H.sub.4_(CN).sub.2. However, the resulting dinitrile is_converted to_xylene diamine_[C.sub.6 H.sub.4 (CH.sub.2 NH.sub.2).sub.2 [ which in turn is converted to_1,4-xylylene diisocyanate via phosgenation. This overall_process is different from_the present_invention.
The_phosgene approach is_highly_unsuitable since_the reactant phosgene gas is highly toxic_and the_process highly wasteful of material and_energy since a reactant_HNO.sub.3_is manufactured by oxidation of ammonia_(NH.sub.3) and after nitration of benzene_to nitrobenzene it is reduced._One_approach_to overcoming the wastefulness of_the process was to directly aminate_the benzene with_ammonia as is taught in U.S. Pat._No._4,031,106. However, this approach is not_yet_commercially useful because of the inefficiency_of_the_amination, even under severe reaction