CA2166321A1 - Block copolymer, method of making the same, diamine precursors of the same, method of making such diamines and end products comprising the block copolymer - Google Patents

Abstract

Block copolymers having a repeating unit comprised of polysiloxane and urea segments are prepared by copolymerising certain diaminopolysiloxanes with diisocyanates. The invention also provides novel diaminopolysiloxanes useful as precursors in the preparation of the block copolymers and methods of making such diaminopolysiloxanes. Pressure sensitive adhesive compositions comprising the block copolymer are also provided as are sheet materials coated with the same.

Description

WO 9~/03354 21~ 6 3 2 L PCT/US94/08191 Bl,OCK COPOLYMER. METHOD OF MAKING l~l~ SAME, DI~MINE PRECURSORS OF THE SAME. METHOD OF
MAK~G SUC~I DIAM~ES AND END PRODUCTS
COMPRISING T~IE BLOCK COPOLYMER

FIELD OF l~ INVENTION
The present invention relates to organopolysiloxane-polyurea block copolymers, a method of making the same and certain novel minopolysiloxanes useful as precursors for making the block copolymers.
The invention also relates to methods of making the novel diaminopolysiloxanes. In a further aspect, the invention relates to products which employ the block copolymer such as p~s~.ur~-sensitive adhesive compositions.

BACKGROUND OF THE INVENTION
Block copolymers have long been used to obtain desirable pelrol~ ce characteristics in various products such as films, adhesives and molded articles.
Block copolymers are particularly useful because the blocks can be chemi~lly tailored to optimize desired char~rteri.~tics.
Siloxane polymers have unique pl~llies derived mainly from the 25 physical and chemic~l char~ctçn~tics of the siloxane bond. Such pl~c;l~ies include low glass transition l~lllp~l~lures, high thermal and oxidative stability, UV rç~i.ct~nce, low surface energy and hydrophobicity, good electrical prop~lLies and high permeability to many gases. They also have very good biocompatibility and are of great interest as biomaterials which can be utilized30 in the body in the presence of blood.
Unfortunately, despite these desirable features, most polydimethylsiloxane polymers based solely on polydimethylsiloxane lack tensile strength. Consequently, several references suggest ways for conveniently WO 95/03354 ~ 6 3 2 1 PCT/USg4/0819 increasing the strength of siloxane polymers especially elaslo,nc~ls. For eY~mp1~, various references suggest that mech~ni~ rupelLies of polysiloxane polymers can be improved subst~nti~lly through the preparation of block copolymers which include as a lc~ealillg unit a `'soft" polysiloxane block or segm~nt and any of a variety of other "hard" blocks or segmentc such as f polyu,t;L}Ialle. See, for eY~mple, (Ward) U.K. Pat. No. GB 2 140 444B, published Jun. 5, 1985, (Cavezzan et al) U.S. Pat. No. 4,518,758, (Nyilas) U.S. Pat. No. 3,562,352, and (Kira) U.S. Pat. No. 4,528,343.
~egmPntecl polydimethylciloY~ne polyurea elastomers, with cilicone se.~m~nt mol~ul~r weights less than about 4,000, pr~ d from silicone minPc and diisocyanates are described in Polymer, Vol. 25, pages 1800-1816, Decçmher, 1984.
However, elastomers with silicone segment molecular weights greater than about 4,000 have not been described in the lil~ldlule. This reflects the difficulty of ob ail,i"g silicone ~ mines of s~Mcient purity having molecular weights greater than about 4,000. Inherent in the conventional method of "11;nn of .cilicon~ minPs iS the generation of monofunctional and nonfilnctio~ ulilies in the desired rli~mine product. These coi~ ntc have the same average molecular weight as the ~i~mine but cannot be removed from the rli~minP. Thus, elastomers obtained by chain eYtenciQ~ of these silicones contain these inlpulilies, and the elastomeric ~r~,~lLies are negatively affected by them. For example, monofunrtion~l impurities inhibit the chain eYt~ncion reaction and limit the ~ t of optimum molecul~r weight, and thereby optimum tensile strength, of the polyurea. Nonfunctional silicone oil 25 can act as a plasticizing agent, which also contributes to reduction in tensile strength, and such oil can bloom to the surface of the elastomer and be transferred, e.g., to a pl`eS~iUle sensitive adhesive in contact with it, resulting in loss of adhesive p~o~e~Lies.

30 SUMMARY OF'l~ INVENTION
The present invention provides organopolysiloxane-polyurea block copolymers having the conventional eYcellent physical pl~llies associated Wo 95/033s4 ~16 6 3 21 PCTIUS94/08191 with poly.~iloY~nes of low glass transition tclllpcl~ture, high the~n~l and oxida.tive stability, UV re~i~t~nce, low surface energy and hydrophobicity, good-PlP~tlic~l pr~pelLies and high permeability to many gases, and the ~ ition~l desirable pro~clly of having eY~Rlle.nt mPich~nic~l and elastomeric properties.
S T~he organopolysiloY-~nP--polyurea block copolymers of the present invention are tho~lght to have good biocolll~aLibility and are capable of being utilized in ~itu~tioll~ where convc~.lion~l poly.~iloY-~ne polymeric m~tP.ri~l~ have found use.
The organopolysiloxane-polyurea block copolymers of the present invention are particularly useful, when t~.kifiP~ with a coll-palible t~nkifier resin, as prcs~ule 10 sensilive adhesive co,llposi~ions.
The organo~ilo~nP--polyurcLllalle block copolymers of the present invention are segm~-nted copolymers of the (AB)n type which are obtained through a con-1en.~tion polymPri7~tion of a difunctional organopoly~ilox~n~.
amine (which produces soft segm~nt) with a diisocyanate (which produces a 15 hard seg...t nt) and may include a difi-nc tion~l chain extender such as a difunctional amine or alcohol, or a IlliXLUl~ thereof.
More ~rec-ifi~lly, the present invention provides organopoly~ilo~nP--polyurea block copolymers comprising a rcpe~ling unit ~,csentcd by Formula I, as follows, the organopolysiloxane-polyurea block 20 copolymer comprising the following lcpeaLillg unit:

o : c ~ . o o o --Z--N~--1--Y~ Y--~ --Z--N~--A--B--A~--m I

where:
Z is a divalent radical se~ected from the group con.~i.cting of phenylene, alkylene, aralkylene and cycloalkylene;

WO 95/03354 21~ 6 3 21 PCT/US94/08191 --Y is sP.lect~ from the group con~i~ting of alkylene r~ of 1 to 10 carbon atoms, aralkyl r~dic.~l.c, and aryl r~-liç~
R is at least 50% methyl with the balance of the 100% of all R
r~-lir~1~ being selçct~d from the group con~i~ting of a monovalent S alkyl radical having from 2 to 12 carbon atoms, a substitutedalkyl radical having from 2 to 12 carbon atoms, a vinyl radical, a phenyl r~ 1, and a subsLilu~d phenyl r~t1ir~1;
D is select~ from the group con~i~ting of hydn~gen, an alkyl radical of 1 to 10 carbon atoms, and phenyl;
B is sçlçctçd from the group con~i~ting of alkylene, aralkylene, cycloalkylene, phenylene, polyethylene oxide, polypr~ylene oxide, polyl~l ~..lethylene oxide, polyethylene adipate, polycaprolactone, polybuhrii~ne, and mixtures thereof, and a radical completing a ring structure int.l~-ling A to form a heterocycle;
A is s~ ct~ from the group con.~i.etin~ of -O- and -N-G

where G is sPlçcted from the group con~ ting of hydrogen, an alkyl radical of 1 to 10 carbon atoms, phenyl, and a radical which completes a ring structure inc.l~l-ling B to form a helelo~ycle;
n is a number which is 70 or larger; and m is a number which can be zero to about 25.
In the yrert;lled block copolymer, Z is s~lçctçd from the group con~i~ting of hey~mP.thylene, methylene bis-(phenylene), isophorone, tet~m~.thylene, cyclohexylene, and methylene dicyclohexylene and R is methyl.
A method of making the organopolysiloxane-polyurea block copolymer 30 is also provided. The method comprises polym~ri7.ing, under reactive conditions and in an inert atmosphere: -~
(1) a di~min~q having a molecular weight of at least 5,000 and a molecular structure l~l~senled by Formula II, as follows:

WO 95/03354 ~ ~ 6 6 3 2 ~ - PCT/USg4l08lgl D R R R D
HN--Y--' i O--' i O~ Y--NH
P, R n R

II
where R, Y, D and n are as defined in Formula I above;

(2) at least one diisocyanate having a molP~ r structure ,~resenled by Formula m, as follows:
OCN-Z-NCO
m lS where Z is as defined in Formula I above; and (3) up to 95 weight percent rli~mine or dihydroxy chain eYten~er having a molecular structure ~ey~esenled by Forrnula IV, as follows:

H-A-B-A-H
IV

where A and B are defined above.
The combined molar ratio of silicone (1i~mine, ~ mine and/or dihydroxy 25 chain eYt~n-ler to diiso~;ya~lale in the reaction is that suitable for the formation of a block copolymer with desired p,~lies. Preferably the ratio is ~ in in the range of about 1:0.95 to 1:1.05.
The diisocyanate useful in the reaction can be a phenylene diisocyanate such as toluene diisocyanate or p-phenylene diisocyanate, h~x~m~thylene 30 diisocyanate, aralkylene diisocyanate such as methylene bis-(phenyl-isocyanate) or tetramethylxylene diisocyanate, or a cycloalkylene diisocyanate such as WO 95/033~4 ~ ; 6 3 ~ 1 PCT/US94/08191 --isophorone diisocyanate, methylene bis(cyclohexyl) diisocyanate, or cyclohexyl diisocyanate.
The reaction to make the novel block copolymer involves the use of the novel organopolysiloY~nF~ mine r~,ese~ d by Formula II.
A method of making the organopolysiloxane ~ mine re~resenLed by Formula II is also provided. The method involves:
(1) combining under reaction conditions and in an inert atmosphere:
(a) amine filnction~l endblocker of the molecular structure rep~esenled by Formula V, as follows:

R R
--Y--'i O~ Y--I
D 1~ P~ D

where D and Y are as defined in Formula I, and each R is indepen-l~Pntly sPlP~tecl from the group con~ ting of a monovalent aLkyl radical having from about 1 to about 12 carbon atoms, a substituted alkyl radical having from about 1 to about 12 carbon atoms, a phenyl radical and a substituted phenyl radical;
(b) sufficient cyclic siloxane to react with said amine filnction~l endblocker to form a lower molecular weight organopoly~ilo~n~
minlo having a molecular weight less than about 2,000 and a molecular structure r~,esellted by Formula VI, as follows:

HN--Y--' i O--' i~ Y--NH
R R R

VI

4 ~16 6 3 21. PCT/US94/08191 where D, R, and Y are as defined in Formula I, and x is a number in the range of about 4 to 40;
S (c) a catalytic amount not to exceed about 0.1% by weight based on the llltim~tP weight of the final organopoly~ilo~r~nP .1i~minP of a novel nl,~lly anhydrous amine silanolate catalyst of a molPc~ r structure ~resented by Formula VII, as follows R
NH--Y~ O-M+
D P, VII

where D and Y are as defined in Formula I and each R is in-lep~.n-iently selecteA from the group con~i~ting of a monovalent alkyl radical having from about 1 to about 12 carbon atoms, a substituted alkyl radical having from about 2 to about 12 carbon atoms, a phenyl radical and a substituted phenyl radical, and M+ is a cation sçlect~d from the group con~i~ting of K+, Na+, or N(CH3)4+, with N(CH3)4+ being prefelled;
(2) continuing the reaction until subst~nti~lly all of the amine functional endblocker is con~umPA; and (3) adding additional cyclic siloxane until the novel organopolysiloxane ~ mine lc~lt;sented by Formula II is obtained.
The p-erell~d amine .~ nol~t~. catalyst is 3-amino-propyl dimethyl tetramethylammonium ~ nol~tP The catalytic amount of the amine silanolate catalyst is preferably less than 0.5 weight percent, most preferably O.OOS to about 0.03 weight percent, based upon the Illtim~te weight of the final organopolysiloxane .
The ple~elled reaction conditions comprise a reaction temperature range of about 80 C. to about 90 C., a reaction time of about S to 7 hours, and the dropwise addition of the additional cyclic siloxane.

WO 95tO3354 ~ L 6 ~ 3 21 PCTtUS94/08191 --Also provided is a method of making an organopoly.~ilo~ne t1i~mine having a molecular weight of at least 2000 and having less than or equal to about 0.010 weight ~o silanol i~ulilies, and being plc~ared by the steps of (1) combining under reaction con-lition~:
(a) amine functional endblocker of the general formula D R R D
HN--Y--' i O~ Y--NH
P~

where:
Y is SPlPct~d from the group con~i~ting of an alkylene radical of 1 to 10 carbon atoms, araLkyl, and aryl r~ic~ ; D is SPlP~t~ from the group con.~i~ting of hydrugen, an alkyl radical of 1 to 10 carbon atoms, and phenyl;
and R is each indepPn-iPntly sPl~ted from the group con~i~ting of a monovalent aLkyl radical having from 1 to 12 carbon atoms, a substituted alkyl radical having from 1 to 12 carbon atoms, a phenyl radical, and a substituted phenyl radical;
(b) sl-fficjPnt cyclic siloxane to react with said amine functional endblocker to form an inte~mP~ te organopolysiloxane ~i~mine having a molecular weight less than about 2,000 and general formula D R R R D
HN--Y--~ i~--~ i~--' i--Y--R R ~ R

~ 3 ~ ~

where:
Y and D are as defined above; R is at least 50% methyl with the balance of the 100% of all R radicals being ~l~ct~d from the group con~i~ting of a monovalent alkyl radical having from 2 to 12 carbon atoms, a substituted alkyl 5 radical having from 1 to 12 carbon atoms, a vinyl r~-lic~l, a phenyl radical and a ~ liluled phenyl radical; and x is a number in the range of about 4 to about 40; and (c) a catalytic amount of a co.ll~ound çh~r~cteri7~d by having a molecular structure l~ sen~ed by the fnrm R

--Y~
D P

where: VIII
Y and D are as defined above; R is each indepPn-lently s~l~ctçd from the group con~i~ting of a monovalent alkyl radical having from 1 to 12 carbon atoms, a ~ubsliluLed alkyl radical having from 2 to 12 carbon atoms, a phenyl radical, and a ~ubslilul~d phenyl radical; and Q+ is selected from the cations Cs+ and Rb+;
(2) continuing the reaction until subst~nti~lly all of said amine functional endblocker is con~m~A;
(3) adding additional cyclic ~ilo~r~ne in an amount required to obtain the organopolysiloxane ~ mine of the desired molecular weight;
(4) le,."i~ g the reaction by addition of a volatile organic acid to form the organopolysiloxane ~ mine of at least about 2000 molecular weight having less than or equal to about 0.010 weight percent silanol i~pulilies; and (5) removing any residual cyclic siloxanes and volatile impurities.
Preferred amine silanolate compounds of Formula VIII are cesium 3-30 aminopropyklimethyl silanolate and rubidium 3-aminopr~yklimP~thyl silanolate.The catalytic amount of the amine silanolate catalyst is preferably less than 0.025 weight percent, most preferably 0.0025 to about 0.01 weight percent, 3 2 1 1~

based upon the llltim~tr weight of the final organopoly~iloY~nr ~ mine Preferred volatile organic acids are~-l~cted from the group con~i~ting of aceticacid, trimethylacetic acid, trichloroacetic acid, trifluoroacetic acid, benzoic acid, and Il~Lur~s thereof. The plefell~d reaction conditions comprise a 5 reaction l~ pe~ A~lll C~ range of about 150 C to about 160 C and a reaction time of about 4 to 8 hours.
The present invention also relates to a m~th~d of making an organopoly~ilox~n~ mine having a molecular weight greater than about 2000 and having less than or equal to about 0.010 weight % silanol impurities, 10 comprising the steps of:
(a) combining under reaction conditions (i) an amine functional endblocker r~r~sented by the formula IX

I R R D
HN--Y--' i O--' i--Y--NH
E~ R ,c IX
wherein;
Y is selected from the group cqn~i~ting of alkylene radicals comprising about 1 to about 10 carbon atoms, aralkyl r~-lic~l~, and aryl r~-lir~
D is sPl~cted from the group con~i~ting of hydrogen, an alkyl radical of about 1 to about 10 carbon atoms, and phenyl;
R is at least 50% methyl with the b~l~nee of the 100% of all R radicals being selected from the group con~i~ting of a monovalent alkyl radical having 2 to 12 carbon atoms, substituted alkyl radical having ~f~om 2 to 12 carbon atoms,a vinyl radical, a phenyl radical, and a substituted phenyl radical; and x l~resellts an integer of about 1 to about 150;
(ii) sufficient cyclic siloxane to obtain said organopolysiloxane di~mine having a molecular weight greater than about 2000;

WO 95/033~4 ~ 1 6 6 3 21 PCT/US94/08191 (iii) a catalytic amount of a compound selected from the group con~i~ting of cesium hydroxide, rubidium hydroxide, cesium silanolates, rubidium ~ nol~tPs, cesium polysiloxanolates, rubidium polysiloxanolates, and Ul'eS thereof;
S (b) co~ ;ng the reaction until ~ubs~ lly all of said amine functional endblocker is con.~umPd;
(c) l~ h~g the reaction by the ~iition of a volatile organic acid to form a ~ lulc of an organopoly~iloY~ne ~ mine having greater than about 0.010 weight % silanol illl~uliLies and one or more of the following: a cesium salt of the organic acid, a rubidium salt of the organic acid, both a cesium salt of the organic acid and a rubidium salt of the organic acid; wherein a molar excess of organic acid is added in relation to the compound of elemPnt (a)(iii);(d) con-lPn~ing under reaction conditions a suffic;~Pnt amount of said silanol impurities to form an organopolysiloxane di~minP- having less than or equal to about 0.010 weight % silanol illlpuliLies; and (e) optionally removing said salt.

DETAILED DESCRIPTION OF THE INVENTION
The reaction to produce the block copolymer of the invention involves mixing under reactive conditions the organopolysiloxane ~ mine, ~ minP
and/or dihydroxy chain extender, if used, and diisocyanate to produce the block copolymer with hard and soft sPgment~ respectively derived from the diisocyanate and organopolysiloxane ~ minP The reaction is typically carried out in a reaction solvent.
Preferred reaction solvents are those which are unreactive with the diisocyanales and which ~ h~l~in the re~t~nt~ and products completely in solution throughout the polymerization reaction. It has been found that chlnrin~t~d solvents, ethers, and alcohols perform best in the case of aliphaticdiisocyanates with methylene chloride, tetrahydloru,dn, and iso~ropyl alcohol being y~cfel~ed. For aromatic diisocyanates such as 4,4'-methylene-bis-phenyl-isocyanate (MDI), a ~ clure of tetrahydruru,~l with WO 95/03354 2~6 6 3 2~ PCT/US94/08191 --10% to 25% by weight of dipolar aprotic solvent such as dimethyl-form~mids is ~ff;llf~d.
The starting m~tf ri~l~ and reaction solvents are usually initially purified and dried and the reaction is carried out, under an inert atmosphere such as dry5 nitrogen or argon.
Suitable diiso~;y~ ates include toluene diiso~;yal~aLe and hf Y~mf tllylene diisocyanale. Prerf.red diiso~;y~u~ates include 4,4'-methylene-bis-phenylisocyanate (MDI), 4,4'-methylene-bis (cyclohexyl)diiso~;y~at~ (H-MDI) and isophorone diiso~;yanate.
Chain eYtendPrs may be incorporated with the other re~rt~nt~ to provide other physical plu~lLies in the çl~imfcl block copolymer. The chain e~tPnders may be short chain rli~minfs such as hrl~mrll,ylene tli~mine~ xylylene ~ minf, 1,3-di(4-piperidyl)propane (DIPIP), N-2-aminoethyl propylmethyl~limPthoxysilane (DAS), pi~f ,.,;,-e and the like, with piperidyl 15 ~r~ane being prefelled.
Polymeric ~ minPs as well as polymeric glycols may also be copolymPri7ed with the poly~ilo~r~ne. ~ mines, diisocy~laLes, and other optionalnon-silicone soft segmP-nt~ as chain PYtentlPrs to impart ~drlition~l desirable ~n~llies to the silicone polyureas. The res--lt~nt copolymeric segmPnt~ may 20 comprise from as little as 5% to as much as 95% of the copolymer formulation, d~Ppentlin~ on the l,r~c;lLies of the resl~lt~nt copolymer desired.
Polymeric di~minP.s useful as non~ilirone soft segmPnt~ are those which can be obtained with functinn~lity appro~ ing 2.0 such as polytetr~mP-thylene oxide di~mine of from 5,000 to 25,000 molecular weight, with a molecular 25 weight in the range of 8,000 to 15,000 being most prer~lled. Suitable polymeric diols include polytetramethylene oxide glycol, polyethylene oxide glycol, polyethylene adipate glycol, poly~r~ylene oxide glycol, polybllt~-liPne glycol, polycaprolactone glycol, and the like. In ~r~aring the polyureas from a mixture of polysiloxane and polytetramethylene oxide ~ mines, the di~mines 30 are dissolved together in a suitable solvent such as methylene chloride and the diisocyanate and chain eYtender, if used, are introduced into the l~,i,LLure, preferably at a combined amine to diisocyanate molar ratio of 1:0.95 to 1.05. A

wO 95/03354 2 ~ ~ ~ 3 2 1 ! PCT/US94/08191 two stage procedure is required to copolymerize the polymeric glycols with silicone ~ mines in which the glycol is first heated with the diisocyanate in aninert solvent such as toluene or tetrahydl.~rù,~l with a catalytic amount of a tin co~n~l~und such as stannous octoate or dibutyl tin f~ t~P- for a suffi~iPnt S amount of time, e.g., one half to one hour, until all of the alcohol groups have been capped with isocyanate. In the second stage, the poly~ilox~nP ~ mine is added followed by any optional ~ ....n~ chain eYtPndPrs to provide the polyether or polyester polyulcll-al e poly~ilox~nP polyurea block copolymer, with the combined molar ratio of amine plus alcohol to isocy~ale preferably being held in the range of l:O.9S to 1:1.05 to provide for complete reaction.
The organopoly~ilo~nP--polyurea block copolymers of this invention, useful as films or co~hng.c, are p~cl)alcd in and cast from solvents.
A ~ignifi~nt feature of the invention is the discovery that subst~nti~lly pure organopoly~ilo~nP ~ s can be produced with a ~l~ s~lected desired molecular weight in excess of S,000 with eYcellPnt difunctionality. It is thought such organopolysiloxane ~i~minPs are produced according to the present invention with such high purity because of the presence of the following key process conditions during the plc~aLion:
1. utilize an anhydrous amino alkyl functional ~ nol~tP catalyst such as tesr~mpthylammonium 3-aminopropyl~imPthy~ n~l~tP;
2. use a minimum amount of this cat~lyst, preferably less than 0.05% by weight based upon the weight of the silicone f~i~mine being plcparcd;
and 3. run the reaction in two stages, as herein described.
As previously mentioned, the reaction to produce the organopoly~iloY~nP
mine employs an anhydrous amine functional ~ nol~tP catalyst lc~rcsented by Formula VII. The prcrellcd catalyst in this polymerization is 3-amino-propyl dimethyl tetr~mPthylammonium ~ nol~tP, itself a novel compound, obtained as - a crystalline solid from the reaction of one molar equivalent of 1,3 bis-(3-aminopropyl) tetramethyldisiloxane with 2 molar equivalents of tetrarnethylammonium hydroxide pentahydrate in tetrahydrofuran under reflux, followed by drying under vacuum for S hours (0.1 mm) at 60 C.

WO 9~/033~4 ~16 6 3 21 PCT/US94/08191 --In the first stage of the re~r.tion, a low molecular weight silicone rli~mine having a structure as defined by Formula VI is pl`c~arcd by reacting anamine functional disiloxane endblocker of the type represented by Formula V
with a cyclic siloxane in the presence of a catalytic amount of anhydrous amine 5 functional .~ nol~t~ esellted by Formula VII in an inert atmosphere such as niLI~gen or argon. The amount of catalyst employed should be less than 0.05 weight pcr~cnl, preferably 0.005 to about 0.03 weight percent, by weight of the re-s--lt~nt ~ mino ~ilic~ne While not wanting to be bound by theory, it is thought that, by using a minimum amount of an anhydrous amine functi~n~l 10 .~ n~ t~ catalyst, the number of inactive chain ends that are produced by catalyst molecules and spurious water are held to a miniml-m The reaction is typically carried out in bulk at a te~ c of 80-90 C., and under these conditions is usually complete in about 0.5-2 hours, as judged by subst~nti~lly complete disap~".~-ce of the endblocker of the reaction 15 ~ lUlG as determined by vaporphase ch~ -atogld~ y. An intermPAi~te organopolysiloxane ~ mine is ob~ ed having a molP~ul~r weight of less than about 2,000 and a mQlecul~r structure re~csellted by Formula VI.
The second stage of the reaction involves the slow addition of the ren ~in~çr of the cyclic ~iloYi~n~. required to achieve the desired mo1~ul~r 20 weight, prcrcl~bly dropwise addition, at such a rate that the cyclic siloxane is incorporated into the polymer about as fast as it is added, usually in about 5 to 7 hours at the reaction ten-pcldlulc of 80-90 C. The desired organopoly~iloY-~ne ~ min~ is produced having a molecul~r weight in excess of 5,000 and a structure as defined by Formula II. By utili7in~ this two-stage method with a minimllm amount of amine functional anhydrous silanolate catalyst, silicone fli~minP.s of Formula II may be con.~i~t~ntly plc~cd in any desired molecular weight from about 5,000 to about 70,000 having eYcs.ll~.nt difunctionality with little co~t~min~tiQn from monofunctional and nonfunctional polysiloxane impurities.
Subst~nti~lly pure, difunctional organopolysiloxane fli~min~.s of Formula II wherein "n" is 30 or greater, having a molecular weight of greater than about2,000, preferably greater than about 5,000, may also be prepared using an WO 95/033~4 216 6 3 21 PCTIUS94/08191 ~ltern~tive, yet related, two stage method. This method consists of combining the amine functional ~ lox~ne endblocker of the type r~rGsGIlLed by Formula V with a cyclic siloxane in an inert atmosphere such as niLI.~gell or argon.
These reagents are then heated and purged with inert gas to dispel water vapor S and the volatile c~ n~, such as carbon dioxide, which effectively poison the sil~nol~t~ polymPri7~tion catalyst. After heating to about 150 to about 160C, a sollltion of the anhydrous cesium or rubidium ~ nr~l~tP catalyst (as described in Formula VIII) in toluene is added. The amount of catalyst employed should be less than about 0.025% by weight, preferably from about 10 0.0025 to about 0.01% based on the weight of organopoly~ilo~ne ~ minP
products. As ~ cu~ed ~, it is thought that the use of minimllm amount of an anhydrous amine functional silanolate catalyst provides a means to reduce the level of undesired monofunctional and nonfilnction~l poly~ilox~ne impuritiesin the final organopolysiloxane ~ mine product.
The reaction is typically carried out in buLk at a lGInPG1~lUre of about 150 to about 160C, and under these contlition~ is usually complete in about 0.5 to about 2.0 hours, as judged by ~llbs~ lly complete disd~ ce of the endblocker of the reaction Illi~lul~ as detellllined by vapor phase chlolllatog,dphy. An inl~;l.--P~ organopolysiloxane ~ mine is obt~ined 20 having a mole~ r weight of less than about 2,000 and a mQlecl-l~r structure selllGd by Formula VI.
The next step of the reaction involves the addition of the rem~inder of the cyclic ~ilo~nP monomer required to achieve the desired molec-ll~r weight.
When the added cyclic ~ilo~nP has been totally con~--med, usually in about one 25 to two hours as judged by vapor phase chrolllal~graphy, the final step of this method involves the addition of an excess of an organic acid in an amount s-lffici~-nt to neutralize the catalyst and le,~ laLG the reaction. Such organicacids must be volatile (i.e. have a boiling point of less than about 100 C at 1- mmHg) so that excess acid may be readily removed with other volatile 30 impurities in a subsequent step of this method which involves heating the Illi~Lule under vacuum. Furthermore, the volatile organic acid must not cause the re-equilibration of the reaction product which would result in the re-WO 95/03354 ~16 6 3 2 ~ PCT/US94/08191 ~

formation of the starting m~tPri~l~. Examples of useful volatile organic acidsinclude but are not limited to those SPlP~t~P~ from the group conci.cting of acetic acid, trimethylacetic acid, trichloroacetic acid, trifluoroacetic acid, benzoic acid, and llliXLul~s thereof. In addition to small amounts of free silanol, this5 process generates the cesium or rubidium salt of the volatile organic acid or acids employed in tF~ ;ng the polym~ri7~ti~ n. These acid salts are insoluble in the .cilicone di~mine product at ambient lell.pel~lules, and are removed by conventional mPthorlc after the residual cyclic cilox~n~P.s and volatile impurities have been fliCtillP~l off under high vacuum at 150 to 160 C over a 10 period of about two to three hours.
Significantly, with prolonged heating (i.e., 4 to 10 hours at elevated lelllpt:ldtUl~S), the cesium and rubidium salts have been found to serve as effective catalysts for the con~len.C~tion of the rçm~inin~ silanol inl~ulilies (i.e., tt;....;"~l silanol, or -SiOH moi~P.tiP~C, such as organopolysiloxanes having 1 15 terminal silanol group and 1 tP-rmin~l amine group and ol~ o~olysiloxanes having 2 termin~l silanol groups) to Si-O-Si linkages, thus converting most mono~minP and non~min~ functional i~ u~ilies into ol~anol)olysiloxane minP.s. With this discovery, it is also possible to p~ high purity, high molecular weight organopolycilox~ne ~ min~s without the neCps~ily of utili7ing 20 minimum amounts of anhydrous amine functional .cil~nol~tp catalysts. Catalytic compounds selected from the group con.ci.cting of cesium hydlo"ide (which may be in aqueous solution), rubidium hydr~ ide (which may be in aqueous solution), cesium polysilox~nol~tPs, rubidium polycilox~n~lates, and ~ Ul~S
thereof, although initially generating high levels of silanol end groups, 25 ~lltim~tP.ly provide organopolycilox~ne rli~minPs of equivalent purity to products obtained from the anhydrous catalyst through the conrlen~tion of telll~inal silanols. By utili7ing this method with a cesium-based or rubidium-based catalyst, organopolycilox~ne di~min~s of Formula II wh~;le;n "n" may be further defined as 30 or greater may be consistently and conveniently prepared 30 in any desired molecular weight from 2,000 or more, typically about 5,000 to about 250,000 or more, having excellent difunctionality with little coi";-lllin~tion from monofunctional and nonfunctional polysiloxane i~n~u~iLies.

WO 95/03354 ~16 ~ 3 21 PCT/US94/08191 This method, which is espe~ lly useful for ~ie~ing organopolysiloxane tli~minPs of Formula II having very high molecul~r weight (i.e., greater than 70,000) and high purity, comprises the use of a silicone mi1~e endblocker r~lesel~led by Formula IX. In contrast to the other S mPthorl~ of the present invention which employ monomeric amine functional disiloxane endblockers, this amine functional endblocker may further comprise oligonneric and polymeric silicone ~ mines having a mol~c~ r weight of up to 10,000 and having any level of silanol content as a starting m~teri~l Following the relmoval of volatile co~t~"li~-~nl~ such as water or carbon dioxide from these 10 m~tPri~l~, a Illixlurc of the amine fim~tio~l endblocker and cyclic siloxane is heated to a le---perdture of about 100 to about 160 C, preferably to about 150 to about 160 C, in an inert atmosphere such as nitrogen or argon. The amount of cyclic siloxane starting m~tPri~l required d~Ppen~ls both upon the molecular weight of the amine functional endblocker and the desired molecular weight of 15 the organopolysiloxane ~ min~. product. To this heated .ni~Lurc is then addeda catalytic amount of a solution of a co-np. und sPlPctP~1 from the group con~ ting cesium hydroxide, rubidium hydroxide, cesium ~ nol~t~s~ rubidium nol~tP.s, cesium polysilox~nol~tPs" rubidium polysiloxanolates, and Illi~lulcs thercof. This catalytic amount depen-l~ upon the reactivity, availability and 20 expense of the col--pound ~1tili7P~. Examples of useful amounts of co...poui-ds sPlect~d from the group con~i~ting of cesium hydroxide, rubidium hydroxide, and --i~u,cs thereof range from about 0.005 to about 1 weight percent based upon the total weight of the endblocker and cyclic siloxane. The more highly reactive and less common compounds selP~ct~Pcl from the group con~i~ting of 25 cesium silanolates, rubidium ~ nol~tPs, and Illi~lulcs thereof may be used at a lower concentration, typically from about 0.005 to about 0.3 weight percent based upon the total weight of the endblocker and cyclic siloxane. This reaction is then continued until completion (about 0.5 to about 2 hours) when - the expected proportion of the mixed cyclic siloxane coproduct of this reaction 30 is obtained (approximately 10 to 15 % by weight) as determined by vapor phase chr~""atography.

WO 95tO3354 ~ 1 ~ 6 3 2 1 PCT/US94/08191--After this level of mixed cyclic eilo~ne material is r~Ache~, then the reaction mi~lure is cooled and a s~fflçient amount of a volatile organic acid such as those described above is added to provide a solution of neutral or acidic pH. ~çnPrA11y, the lGI~ 1d~UI`G must be cooled below the boiling point of the 5 organic acid, preferably to telllpGld~ulG of about 60 to about 80 C. Addition of such organic acids te ...i~-~les the reaction and causes the formation of the organopoly~iloY~nP ~liAminP product of the desired molecular weight, but also inrllu~e~e a high level of silanol conl~ining~ mono~minp~ and nona~ine functional polyeiloY~ne impurities and a small lu~LiLy of residual mixed cyclic eiloY~n~
10 I)y~r~lucts. An additional product of this step is the cesium and/or rubidiumsalt formed by the reaction of the catalyst and the organic acid used in the ~r.l ...;nA~;on of the rPActit)n.
This "~i~lure of impure organopolysiloxane ~ mine and cesium and/or rubidium salt is then heated to about 130 to about 160 C for a period of about lS 4 to 8 hours under vacuum conditions. As described above, at elevated telll~ldlul~s the cesium and/or rubidium salts present in this Illi~lUlG act to catalyze the con~iene~tion reaction of substAnti~lly all silanol impurities (to provide a product having less than 0.010 wt % silanol i~nl~ulilies). The vacuum is n~e~s~ly to encourage this reaction as the vacuum contimlously removes the 20 water produced as a result of the conr1en.e~tion of the silanol groups to form Si-O-Si linkages and the formation of ~ul,st~.-l;~lly pure, difunctional organopolysiloxane rli~min~s of the present invention. The vacuum also provides a means to remove the residual mixed cyclic siloxane fraction from the product. As an optional final step, the le~ g insoluble cesium and/or 25 rubidium salt may be removed from the organopolysiloxane ~ mint~. by any conventional method, such as filtration or cent-irugation.
The prior art method for the p~ ;on of amine termin~t~d silicones from the equilibration of cyclic siloxanes, amine functional disiloxanes and basic catalysts such as tetramethyl ammonium hydroxide or siloxanolate has 30 proven ImeAtiefActory for obtainillg diamino organopolysiloxanes of molecularweight in excess of 4,000 with good difunctionality. These poor results are thought to be caused by a number of ~eletPrious factors inherent in the previous WO 95/03354 ~ 3 21 PCT/US94/08191 methods, which include running the reaction in a single stage or all at once with the catalyst, amine functional endblocker and all the cyclic siloxane togethi r.This results in incomplete incorporation of endblocker and higher than calculated mqlec~ r weights. The use of an excessive amount of a 5 nonfunctional hydldLed catalyst produces a .~ignifi~nt ~er~~ ge of non-amine t~....in~ed silicone polymers as i~pulilies in the final product. These results are obviated in the method of the present invention by the use of an esse..l;~lly anhydrous amine filnction~l catalyst at a minimllm concentration in a two-stage reaction as described above.
The sæ.~ ~ polysiloxane block copolymers of this invention can be ~,epa~d in a wide range of useful piop~,lies through variations in the ratio of soft segmPnt~ to hard segm~nt the nature of the chain eYten~ers and other polymers employed, and the molecular weight of the polysiloxane segment For example, the combination of relatively low molecular weight (4,000-7,000), 15 siliccne seg~ with relatively high hard segmi~nt content provides stiff, hard, yet flexible rubbers It has been discovered that these copolymers are suitable for use as release co~tings for a variety of ~r~s~ e-sensitive adhesives. They have a high degree of difunctionality with little con~ lion from monofunctional or nonfunctional siloxane i-l~LIufilies~ virtually elimin~ting re-adhesion problemsThey have good stability in solution, are film-forming, and have um~su~lly high strength plus desirable m~rh~nic~l and elastomeric plo~llies. In ~cl-lition~ they do not require high temperature curing or long proces~ing times, a decided advantage in ples~ul~-sensitive tape m~nllf?~ctllring.
The block copolymers of this invention, for most applications, do not require curing to achieve their desirable pr~ellies, but yield tough films upon drying. Where additional stability, solvent re~i~t~nce or other additional strength is desired, the silicone block copolymers can be cro~link~ after casting or coating by any of the conventional methods described in the art, such as 30 electron beam radiation, or use of peroxides.
As mentioned previously, the segmçnt~d copolymers of this invention may be pl~ared with a wide range of useful properties through variations in WO 95/03354 ~ 1 ~i 6 3 2 i PCT/US94/08191 the ratio of soft segmentc to hard segm~ntc, the amount and nature of the chain extenders employed, and the molecular weight of the polysiloxane segment These variations give rise to varying amounts of release, i.e., from 10 g/cm or less, to about 350 g/cm. Certain copolymers are especially useful as S low-adhesion b~ Irci7~s (LABs) for removable l,le~u.~-sensitive adhesives suchas m~1ring tapes. LABs for tapes in roll form ideally exhibit release toward theadhesive of about 60 to 350 g/cm width. The plef~l~d hard segmPnt content for copolymers used as release agents and LABs is from about 15 % to about 70%. P-~ r~l.ed ranges vary, depending on the type of adhesive and its ultim~tp 10 use, i.e., the plc~r~lled range for LABs used in m~ ing tapes is from about 25% to about 60%. Copolymers having this range exhibit the n~ç~
combination of adequate unwind on fresh tape and moderate unwind after adverse aging conditions of heat and humidity, plus acceptable paint m~king ~elrc "~ ce, paint flaking re~i~t~nce and the ability to hold when used in 15 uv~l~ing applications.
Block copolymers of m~Ainm molecular weight silicone segm~nt~
(7,000-25,000) alone, or combined with other elasLo~ lic blocks and a hard segmtont content in the 15-25% range, provide highly elastic, rç~iliPnt, quite strong silicone elastomers. With the high difunction~lity of the silicone fli~min~s 20 of this invention, it is possible to p.~;p~ silicone elastomers even with very high molecular weight silicone se~mPnt~ (25,000-70,000) and hard segment content as low as 0.5 to 10%. Such polymers are extremely soft and deformable and n~hlr~lly of low tensile strength; however, it has been discovered that when these silicone polyureas are blended with an 25 a~ox~ ply equal weight of hydroxy-functional silicone t~ kifi~r resins commercially available as the MQ series, such as "MQ" SR-545 from the Gen~r~l F1~tric Co-~-p~y, a new type of silicone pressure-sensitive adhesive is obtained. Through variation in silicone molecular weight and hard segmPnt content, ~res~ule-sensitive adhesive can be formulated with an optimum balance 30 of tack, peel adhesion, and shear holding p-up~ties without the neces~ity of post-curing reactions. Furthermore, since the cohesive strength of these polymers is a result of physical forces of attraction between urea groups and not ~ g ~ 2 ~

çht mit~l cross-linking, these silicone polyurea p,es~.lre-sensitive adhesives can be coated onto tapes by hot melt extrusion processes.
This invention is further ~ tr~tecl by the following examples which are not inten~ed to be limiting in scope. Unless intlic~t~l otherwise, the molecular5 weights refer to number average molecul~r weights.

Prc~ on of the Catalyst A 100 ml three-necked round bottom flask equipped with m~gn~ti-~.
10 stirrer, argon inlet and conden~pr fitted with a drying tube was ch~ ed with 12.4 g (0.05 mole) of 1,3-bis (3-aminopropyl) t~t~m~thyldisiloxane, 18.1 g tetrarnethylammonium hydroxide pentahydrate and 30 ml of tetrahydn)ru~
The nli~lUlC; was stirred and heated under reflux in an argon atmosphere for 1.5hours until a vapor phase chromatograph (VPC) showed complete disap~.~n~e 15 of the disiloxane peak. Upon cooling, the mi~lUlC' sep~ ~l into two layers.
The tetrahydrofuran was allowed to distill from the Illixlulce until a pot ~ml)eldlule of 75 C was achieved, leaving a yellow oil which was stirred and heated under vacuum (0.1 mm) in an oil bath at 60 C until no more volatiles tilled (ca 5 hours). The crude product, a yellow waxy solid, was 20 rc~lysl;llli7~1 from tetrahydrofuran ~I~IF) under argon, filtered and dried under vacuum to give 3-aminopropyl dimethyl tetramethylammonium silanolate as a white crystalline solid. The ch~mic~l structure was confirmed by nuclear magnetic ltsonance analysis (NMR), and the product was stored at room lelllpC'~dlUl`e under argon.

P,~,~dlion of Silicone Diamine A 500 ml three-necked round bottom flask equipped with thermometer, - m~h~nical stirrer, dropping funnel and dry argon inlet was charged with 3.72 30 g bis (3-aminopropyl) tetramethyldisiloxane and 18 g of oct~methylcyclotetra-siloxane (D4) which had been previously purged for 10 mimltes with argon. The flask con~ents were heated to 80 C with an oil bath WO 95/03354 21~; ~ 32 ~ PCT/US94/08191 and a trace (about 0.03 to 0.05 g) of the catalyst described in Example 1 was added via a sp7~t~ The reaction was stirred at 80 C and after 30 minutes of stirring had become quite viscous. VPC showed that the endblocker had completely disappeared. To the result~nt reaction ~ Lulc (which co~ te~l of a 5 1,500 molec~ r weight silicone ~i~minP, cyclic .~ilo~r~nes and active catalyst) was added dropwise over a six hour period 330 g of argon-purged D4, rP~sl-lting in a further rise in the viscosity. ~P~ting the reaction flask co.~ at 80 C
was contin~ed overni~ht The catalyst was deco---posed by heating at 150 C for 1/2 hour and the product was ~L,i~ed at 140 at 0.1 mm ~lcsi,ulc until no more 10 volatiles ~ tillP~ (ca. 1.5 hr.), resulting in 310 g of a clear, colorless viscous oil (a yield of 88% of theoretical). The molecular weight of the product detPrminPd by acid titration was 21,200.
Using this procedure, but varying the ratio of endblocker to D4, silicone mines with molecular weights from 4,000 to as high as 70,000 were 15 ~,cp~ed.

Preparation of Silicone Polyurea Under argon, to a solution of 10.92 g of the 21,200 MW silicone 20 ~i~mine described in Example 2 in 65 ml of methylene chloride was added, all at once, a solution of 0.80 g of isophorone diisocyanate (IPDI) in 15 ml of dichlorom~th~ne, rçsl-lting in a clear solution. To the clear solution was addeddropwise a solution of 0.65 g 1,3-dipiperidyl propane (DIPIP) in 10 ml dichloromPth~ne. Toward the end of the addition, the viscosity rose 25 subst~nti~lly until the m~gnPtic stirrer almost stopped, producing a clear solution of silicone polyurea with a molar ratio of silicone rli~minP./DIPIP/IPDI
of 1:6:7. This solution was cast onto a glass plate and the solvent allowed to e~ol~le overni~ht resnlting in a clear film which was quite strong and highly elastic, and had a tensile strength of 5,210 kPa, 300% elongation, and a 30 permanent set of 5%.
The tensile strength, elongation and permanent set values were all measured at break. The tensile strength, percent elongation, and percent WO 95/03354 ~ ~ 6 6 3 2 ~L PCT/US94/08191 permanent set of the elastomeric m~tPri~ were determined according to ASTM
D 412-68 under ambient conditions at a lel.lpc~l~ture of about 23 C According to this procedure, elastomer spe~im~n~, cast from solvent, were dried, cut to form "dumbbell"-shaped configurations, and the dumbbells were stretched to 5 the breaking point. The ~l.t;lching was accomplished by use of a tensile testing device which recorded the tensile strength during ~ lching until the test ~rPrim~n broke. The tensile strength at break in kPa was recorded. The device also recorded the percent elongation at break to the nearest 10 percent. The percellt permanent set was determined by carefully fitting together the broken 10 pieces of the test dumbbell 10 .llin~lles after the spe~im~n had broken, mP~min~ the co.~lbined length of the broken and stretched spe~imen pieces, dividing this measured length by the original length of the specimen before ~llc;lchillg, and multiplying the quotient by 100.

Pl~ lion of Silicone Polyurea Under argon, to a solution of 2.06 g isophorone diisocyanate (IDPI) in 30 ml dichloromtoth~nP was added a solution of 0.87 g 1,3-dipiperidyl pn~palle (DIPIP) in 20 ml dichlorometh~np~ A solution of 9.8 g of silicone ~ minP of 20 9,584 molecular weight in 20 ml dichloromPth~nP was then added dropwise. To the rçs--lting clear solution was added dropwise a solution of 0.86 g of DIPIP in 10 ml of dichlorometh~ne Toward the end of the addition, the reaction mi~lule became very viscous. After 1/2 hour, the rçs--lt~nt viscous solution was cast onto a glass plate and the solvent allowed to e~/~?ol~te, producing an elastomer25 film of silicone polyurea with a ~ minPlDIpIplIpDI molar ratio of 1:8:9, which was clear, yet stiff with a tensile strength of 8,453 kPa, 200% elongationand 15% permanent set.
Silicone polyureas with a wide range of elastomeric ~lo~ellies were - prepared by procedures illustrated in the examples above. The plvpelLies of a 30 number of these silicone elastomers are listed in Table I below as Examples 5-15.

WO 95/03354 2~1~ 6 3 2 ~ PCT/US94108191--~ ~ ~ 8 8 8 ~
o o o ~oo o t-- X ~ ~ ~ g ~ ~ ~ o o o o o ~ ~ ~ ~

~ ~ ~ _ ` ;~

g 8 8 8 8 ~

o ~- X C~ ~o WO 95/03354 ~ 1 6 6 ~ ~1 PCT/US94/08191 EXAh~PLE 16 Preparation of Silicone Diamine by the Prior Art Procedure To 10 g of oct~mPthylcyclotetrasiloxane (D4), previously purged for 20 minutes with argon, was added 0.08 g of tetramethyl ammonium hydroxide pentahydrate. After stirring at 80 C under argon for 30 min~lt~s, the "li~lure became very viscous in(li~tin~ that conversion to tetramethyl ammonium siloxanolate (the actual catalyst) had occurred. A solution of 2.5 g bis (aminopropyl) tetramethyl disiloxane endblocker (0.01 mole) in 105 g of D4 was added all at once to produce a clear solution which was stirred at 80 C to 85 C under argon to provide an ~cl~med 85% yield of polymer having a theoretical molecular weight of 10,000.
After heating the clear solution for 24 hours, it was determined by VPC
that a substantial amount of endblocker had not been incorporated into the polymer After 48 hours, although VPC indicated that some unincorporated endblocker was still present, the reaction was termin~t~d by heating to 150 C
for 3n minutes. The resultant clear, colorless oil was stripped under aspirator vacuum at 120 to 130 C for one hour to remove all volatiles, leaving 103 g (87% yield) of product.
Titration of the product with 0. lN hydrochloric acid revealed an amino content of 0.166 meq/g or a calculated molecular weight of 12,043 assuming the product is completely difunctional.

Preparation of Silicone Diamine by the Prior Art Procedure The siloxanolate catalyst was prepared as described above from 30 g D4 and 0.20 g of Me4NOH-5H2O. To this catalyst was added a solution of 9.92 g (H2NCH2CH2CH2Si)2-O endblocker (0.04 mole) in 200 g D4. The mixture was stirred and heated at 85 C under argon, and the course of the reaction was followed by VPC After 18 hrs, no endblocker remained in the mixture, and the reaction was termin~ted by heating at 150 C for 30 minutes. Residual cyclics were distilled at 130-150 C at 0.1 mm Hg, to provide the product as a clear, colorless oil which was cooled to room temperature. The yield was 198 g (83%

WO 95/033~4 ~ 2 ~ PCT/US94/08191--yield). Titration of the product with 0. lN HCI gave a molecular weight of 5412. The theoretical molecular weight was 5000.

5 Preparation of Silicone Polyurea Elastomer Using Prior Art Silicone Diamine A 100 ml one-neck round bottom flask was charged with 10.51g of the 12,043 molecular weight silicone .1i~mine of Example 16 and dissolved in 50 ml of dichlorometh~ne. A solution of O.91g H-MDI in 10 ml dichlorometh~ne was added all at once with stirring. The res~-lting clear solution was treated 10 dropwise with stirring with a solution of 0.55 g 1,3-bis(4-piperidyl) propane (DIPIP) in 5 ml of dichloromethane. Toward the end of the addition, the solution became viscous but rem~ined clear. After 1/2 hour, the viscous solution was cast on a glass plate, leaving an elastomeric film, upon solvent evaporation, of a polyurea with a silicone diamine/DIPIP/H-MDI molar ratio of 15 1:3:4.

Preparation of Silicone Polyurea Elastomer Using Prior Art Silicone Diarnine Following the procedure described in Example 17 above, a silicone 20 polyurea elastomer was prepared from 16.03 g of the 5412 molecular weight silicone diamine of Example 16A, 0.62 g DIPIP, and 1.55 g H-MDI in dichloromethane solution. After casting on a glass plate, a clear silicone polyurea elastomer was obtained having the molar ratio of silicone (li~min~/DIPIP/H-MDIof 1:1:2.

Comparison of Elastomeric Properties of Silicone Polyureas Prepared with "Prior Art" Silicone Diamines and Present Invention Diamines The tensile strength, inherent viscosity, elongation at break, and 30 permanent set of the silicone polyureas of Examples 17 and 17A were compared to the properties of analogous silicone polyureas derived from silicone diamines of similar molecular weight prepared by the method of the WO 95/03354 ~ ~ 6 3 2 ~ PCT/US94/08191 present invention. Results are shown in Table II. Included in this Table II are results obtained from the extraction of these films with boiling cyclohexane (Extractable Oil). Significant amounts of free silicone oil were obtained from films prepared using the "Prior Art" diamines when compared to the films S prepared using ~ minçs of the invention. As the molecular weight of the ~i~mine was increased, the relative level of impurities also increased, resulting in progressively inferior physical ~ lies when compared to the polyureas of the present invention.

TABLE II
Ex. Mol. Inherent TensileElongation Perm. Extract.
No. Wt. of Viscosity (kPa) at Break Set Oil (%) Diamine (%) (%) 17A 5,400 .67 6916 555 37 3.0 Prior Alt 17 12,000 .51 3312 290 3 6.0 Prior Art Ex. 3 5,300 .70 8034 550 35 1.0 The invent.
~x. 12 11,300 1.33 8383 500 6 1.2 The invent.

A Silicone-Polyether Polyurea Copolymer A mixture of 8.2 g of a silicone diamine of 8215 molecular weight, 7.3 30 g of 7,300 molecular weight polytetramethylene oxide ~i~mine, and 0.67 g of DIPIP was dissolved in a solvent system of 90 ml isopropyl alcohol and 50 ml of dichloromethane. With stirring at room temperature, 1.11 g of isophorone diisocyanate was added dropwise. Toward the end of the addition, the solution became quite viscous but remained clear and did not gel. A film was cast from ~166~2 ~

the viscous solution, dried and the resulting crystal clear silicone-polyether elastomer had a tensile strength of 19,458 kPa, 650% elongation and 6%
permanent set.

Silicone-Polyester Polyurethane Polyurea Copolymer Elastomers A one liter, three-necked round bottom flask was charged with 19.2 g of 2000 molecular weight polycaprolactone diol ("Tone"-0240 from Union Carbide) and 100 ml toluene. The solution was heated to boiling and a small 10 quantity of solvent was allowed to distill from the flask to azeotropically dry the contents. Isophorone diisocyanate (9.92 grams) was added, followed by three drops of the catalyst dibutyl tin dilaurate. After an initial vigorous reaction, the clear solution was heated under reflux for 1/2 hour. The reaction was diluted to 300 ml with toluene and a solution of 24 g of a 10,350 molecular 15 weight silicone diamine in 50 ml of toluene was added fairly rapidly with stirring. The resulting clear, colorless solution was treated rapidly while stirring with a solution of 6.88 g of 1,3-bis (4-piperidyl) propane in 100 ml of isopropyl alcohol. The reaction became quite viscous but remained clear. After an additional hour, the solution was cast in a tray and the solvent allowed to 20 evaporate. The resulting elastomer, a silicone-polyester polyurethane polyurea, contained 40% silicone and was clear, strong and highly elastic.

Preparation of Pressure-Sensitive Adhesive Using Polysiloxane Polyurea Block 25 Copolymer A 200 ml round bottom flask was charged with 23.23 g of freshly prepared silicone ~ mine of 21,213 molecular weight and 35.3 g of toluene.
The solution was stirred at room temperature and 0.29 of H-MDI was added followed by another 28 g toluene. After 20 minutes, the solution had become 30 very viscous. The pressure-sensitive adhesive was produced by adding 39.2 g of a 60% solution in xylene of an MQ silicone resin composition available from General Electric Company as SR-545. The final solids content was adjusted to WO 95/03354 ~ 1 ~ 63~I PCT/US94/08191 35% by the further addition of 10.3 g of toluene. The resulting pressure-sensitive adhesive solution had a silicone polyurea gum to MQ resin weight ratio of 1:1.
By a similar proce~dure, a number of other silicone polyurea S ~l~s~ e-sensitive adhesives were prepared by blending the polyurea obtained from the reaction of silicone diamines of various molecular weights with equimolar amounts of diisocyanates with an equal weight of MQ silicate resin.
These were coated onto polyester ~llm at a 25 to 33 ~m thickness to provide ~ress,lle-sensitive adhesive flexible sheet materials.
The performance of these examples was evaluated by two standard test metho~ds as described by the American Society of Testing and Materials (ASTM) of Philadelphia, Pennsylvania and the Pressure Sensitive Tape Council (PSTC) of Glenview, Illinois. These are Procedures No. 1 (peel adhesion) and No. 7 (shear strength).
Peel Adhesion ASTM P3330-78 PSTC-l (11/75) Peel adhesion is the force required to remove a coated flexible sheet material from a test panel measured at a specific angle and rate of removal. In 20 the examples this force is e,~lessed in Newtons per 100 mm (N/100 mm) width of coated sheet. The procedure follows:
1. A 12.5 mm width of the coated sheet is applied to the horizontal surface of a clean glass test plate with at least 12.7 lineal cm in firm contact. A
hard rubber roller is used to apply the strip.
2~ 2. The free end of the coated strip is doubled back nearly touching itself, so the angle of removal will be 180. The free end is attached to the adhesion tester scale.
3. The glass test plate is clamped in the jaws of the tensile testing machine which is capable of moving the plate away from the scale at a constant 30 rate of 2.3 meters per minute.

WO 95tO3354 ~16 6 3 ~2 1 PCT/US94l08191 4. The scale reading in Newtons is recorded as the tape is peeled from the glass surface. The data is recorded as the average value of the range of numbers observed during the test.

Shear Holding Strength (Reference: ASTM: D3654-78; PSTC-7) The shear strength is a measure of the cohesiveness or internal strength of an adhesive. It is based upon the amount of force required to pull an adhesive strip from a standard flat surface in a direction parallel to the surface to which it has been affixed with a definite pressure it is measured in terms oftime (in minutes) required to pull a standard area of adhesive coated sheet m~tPri~l from a stainless steel test panel under stress of a constant, standard load.
The tests were conducted on adhesive coated strips applied to a st~inlPs~
steel panel such that a 12.5 mm portion of each strip was in firm contact with the panel with one end portion of the tape being free. The panel with coated strip attached was held in a rack such that the panel forms an angle of 178 with the extended tape free end which is then tensioned by application of a force of one kilogram applied as a h~nging weight from the free end of the coated strip. The 2 less than 180 is used to negate any peel forces thus in~llring that only the shear forces are measured in an attempt to more accurately determine the holding power of the tape being tested. The time elapsed for each tape example to separate from the test panel is recorded as theshear strength.
For the examples of pressure-sensitive adhesives prepared from silicone polyureas without chain extenders, the peel adhesion and shear results are listed in Table III.

WO g5/03354 216 G 3 21 PCT/US94/08191 Table III
Silicone Polyurea Pressure-Sensitive Adhesive 1 Silicone Diamine/H-MDI) Gum: MO Resin = l:ll Ex.Silicone PSA
No.Diamine MW . O
Adhes1on Shear(23 C) (N/100 mm) (Minutes) 22 10,300 12 10000+
21 21,200 43 10000+
23 36,380 61 234 24 53,500 52 382 EXA~IPLES 25-29 P,~d~ion of Pressure-Sensitive Adhesives Using Polysiloxane Polyurea Block Copolymers With Chain Extenders A solution of 17.55 g of 34,000 molecular weight silicone ~ mine 15 (0.0585 meq/g) in 100 ml of methylene chloride was rapidly added at room le,llpeldture with stirring to a solution of 0.54 g of methylene bis [4,4'dicyclohexyl] isocyanate (H-MDI) in 50 ml of methylene chloride. A
solution of 0.12 g of 1,3-bis(4-piperidyl) propane (DIPIP) in 25 ml of methylene chloride was slowly added dropwise resulting in a silicone-polyurea 20 solution which became viscous but did not gel upon completion of the second addition. To prepare the pressure-sensitive adhesive, there was added 30.7 of a 60% xylene solution of MQ silicate resin (SR-545) producing 1: 1 silicone block copolymer to tackifier weight ratio. The solution containing this adhesive was cast on polyester to produce a 33 ,um adhesive film which was tested according 25 to Pressure Sensitive Tape Council (PSTC) Procedures No. 1 (peel adhesion) and No. 7 (shear strength). The results showed 50N/100 mm of peel adhesion to glass and 10,000 plus minutes of shear holding time. This is compared to a number of other pressure-sensitive adhesive compositions of the invention using silicone diamines having differing molecular weight as shown in Table IV.

WO 95/03354~ ~ ~ 6 3 2 ~ PCTtUS94/08191--TABLE IV
Silicone Polyurea Pressure-Sensitive Adhesive (With Chain Extender~
Ex.Silicone-Polyurea Gum PSA
DIPIP Shear Silicone Chain Peel Holding Diamine Extender H-MDI Adhesion 23C
(MW) (Moles) (Moles)N/100 mm Minutes 26 21,000 4 5 10 10,000+
27 21,000 3 4 28 10,000+
28 19,000 2 3 31 25 34,000 3 4 50 29 55,000 2 3 76(split) Prep~r~tinn of Copolymer to be used as Release Agent Composition:
PDMS (MW-5560) 25 parts by weight PCL (MW-1250) 35 parts by weight DIPIP/IPDI 40 parts by weight Procedure:
Polycaprolactone diol (PCL) (35 g) in toluene was refluxed under nitrogen for 30 minutes with the entire charge of IPDI (24.06 g) in the presenceof a catalytic amount (3 drops) of dibutyl tin dilaurate. After reflux, heat wasremoved and toluene was added to dilute the entire mass to 500 ml. After cooling to room temperature, the PDMS diamine (25.0 g) along with 100 ml toluene was added and stirred for 15 minutes.
Then DIPIP (15.94 g), dissolved in 100 ml is~ opallol, was added slowly over a period of 2-3 minutes and stirred for 30 minutes. An increase in viscosity was observed within 5 minutes. The entire solution remained clear and colorless throughout the procedure. A final dilution with toluene brought the solids level to approximately 10% in the solvent blend of 90:10 ratio of toluene:isopropanol. A 1.5 mil urethane saturated smooth crepe paper backing WO 95/03354 ~16 6 3 21 PCT/US94/08191 was primed with a chloroprene latex, Neoprene TM (N-115) made by DuPont, in one trip. In a second trip, the LAB was applied from a metering roll to the opposite side of the backing using a 50% solid solution in toluene/isopropallol. Finally, in a third trip, to the primer side was applied a latex adhesive (45%
5 natural rubber/57% Piccolyte TM S-65, a poly beta-pinene tackifying resin witha ring and ball softening point of 65 C made by Hercules Co.), of coating weight of 4.4 mg/cm2.

10 Composition:
polydimethyl-diphenyl 25% (contains 10 mole %
siloxane (PDMDPS) diphenylsiloxane) (MW 2680) PCL (MW 1250) 35%
DIPIP/IPDI 40 ~o This was prepared and coated similar to procedure used in Example 30.

20 Composition:
PDMS (MW 5590) 10%
PCL (MW 1240) 60%
DIPIP/IPDI 15%
DAS/IPDI 15 %
25 This ~as coated similar to the procedure used in Example 30.

Composition:
PDMS (MW 4900) 23%
PCL (MW 1250) 42%
DIPIP/IPDI 35 %

WO 95/033~4 216 6 3 2 ~ PCTtUS94/08191 This was coated similar to the procedure used in Example 30. The test results from the above exampies are tabulated in Table V.

5 Composition:
PDMS (MW 4900) 20%
PCL (MW 1250) 20%
DIPIP/IPDI 60 %
This was coated similar to the procedure of Example 30.
TESTING
The pt;.roll,-allce of Examples 30-34 was evaluated by the standard test method for peel adhesion as described supra and the unwind test described below.
UNWIND TEST
Testing was accomplished using an Instron-type testing at 90 angle and 90 in/min separation. Data is presented in ounces per inch.
TABLE V
UNWIND
Ex. UNWIND
3 WEEKS RT 65C/16 HRS 90%-50% RH

34 11 17 n/a ~166321 PEEL ADHESION TEST

Ex. PEEL ADHESION TEST
3 WEEKS RT65C/16 HRS 90%-50% RH

RT = 22 C/50% Relative Humidity -65 C/16 Hrs. was followed by 24 Hrs. at 22 C/50% Relative Humidity-90%-50%: Tape was aged at 32 C/90% Relative Humidity for 2 weeks followed by 1 week at 22 C/50% Relative Humidity.
All examples were coated from 5% solutions on ULTRA backing using a metering roll.

EXA~PLE 35 Prepa~ation of cesium 3-aminopropyldimethyl silanolate A 250 ml 1-neck round bottom flask equipped with magnetic stirrer and a condenser fitted with a Dean-Stark water separator was charged with 7.9 g bis(3-aminopropyl) tetramethyldisiloxane (available from Silar Chemical Co.), 20 g of cesium hydroxide as a 50% aqueous solution (available from Aldrich Chemical Co.), and 100 ml toluene. The mixture was heated under reflux for 16 hours with azeotropic removal of water. The resulting clear, colorless solution was cooled to room temperature, the product precipitated by addition of hexane until hazy while cooling in an ice bath, and decanting the supernatantliquid from the solid. This precipitate was re-dissolved in 20 ml of hot toluene, cooled to ambient temperature, and 60 ml hexane slowly added with stirring;
the resulting solid was isolated by filtration under nitrogen and dried in vacuo.
13.4 g of a white crystalline solid (76% yield) was obtained. The 14C and IH
nmr spectra and elemental analysis confirmed the product to be the desired pure, anhydrous cesium 3-aminopropyl dimethylsilanolate.

WO 95/03354 ~ 1 ~ 6 3 2 1 PCT/US94/08191--Preparation of rubidium 3-aminopropyl dime~t ylsilanolate In a similar procedure to that described for Example 35 above, rubidium 3-aminopropyl dimethylsilanolate was prepared from 5.7 g 5 bis(3-aminopropyl)tetramethyl disiloxane and 11.3 g of 50% aqueous rubidium hydroxide in 50 ml toluene. In this case, the product precipild~ed imm~Ai~t~.ly upon cooling of the toluene reaction; filtration and drying gave the desired rubidium silanolate.

Pl~dLion of organopolysiloxane diamine using cesium silanolate as catalyst A mixture of 9.94 g bis(3-aminopropyl)tetramethyl disiloxane and 470.59 g octamethylcyclotetrasiloxane, which had been previously purged by bubbling dry argon gas through it for 20 min, was stirred and heated to 150C;
15 0.319 g cesium 3-aminopropyl dimethyl silanolate of Example 35 (25 ppm) was added, and heating continued. In about 20 minutes, the viscosity had increased ~ignific~ntly, and after 3 hours, analysis of a sample by gas chromatography showed complete di~appea,dnce of the starting aminopropyl disiloxane and the expected equilibrium distribution of cyclic siloxanes. The solution was cooled 20 to ~ 60 to 80 C, 0.03 g acetic acid added, the mixture stirred for 0.5 hour, and then heated to 150C under high vacuum to remove residual cyclic siloxanes.
After 4 to 6 hours, no more volatiles were collected. The mixture was then cooled to room temperature and filtered to separate the precipitated cesium acetate. The resulting clear, colorless oil amounted to an 411.12g (87%)%
25 yield. A sample dissolved in 50% tetrahydrofuran/isopropyl alcohol was titrated with 0. lN HCl to a bromphenol blue end point had a molecular weight of 10,400 (10,000 theoretical).

30 Preparation of organopolysiloxane diamine using cesium hydroxide.
A solution of 7.48 g of bis(3-aminopropyl) tetramethyl disiloxane and 352.9g octamethylcyclotetrasiloxane was purged with argon for 20 min and then WO 95/03354 ~ ~ 6 6 3 ~ ~ . PCT/US94/08191 heated to 150C; 0.06 g (100 ppm) of 50% aqueous cesium hydroxide was added and heating continued for 6 hours until the aminopropyl disiloxane had been con~l-med. The reaction was cooled to 70C, neutralized with excess triethylamine and acetic acid, and heated under high vacuum to remove cyclic 5 siloxanes over a period of at least 5 hours. After cooling to ambient temperature and filtering to remove cesium acetate, the isolated product (315g) titrated to a molecular weight of 10,491 (theoretical 10,000 molecular weight).

EXA~PLE 39 10 Preparation of a organopolysiloxane di~mine from a lower molecular weight organopolysiloxane di~mine A 1000 ml 3-neck round bottom flask equipped with mechanical stirrer, nitrogen inlet, and vacuum adapter was charged with 30 g of an organopolysiloxane diamine having a titrated molecular weight of 5,376 made 15 according to the method of Example 37 and 300 g octamethylcyclotetrasiloxane.The mixture was stirred and heated from 100C to 150C and 0.06 g of cesium silanolate catalyst of Example 35 was added. The viscosity of the reaction rose rapidly and, after 30 min, gas chromatography of a sample showed the equilibrium distribution of volatile cyclic siloxanes. The reaction was cooled to 20 70C, and 0.1 g or triethylamine and 0.06 g acetic acid were added. After stirring for 30 min, a 29Si nmr analysis of silanol content was performed on this intermediate. The intermediate was then heated to 150C under high vacuum of 30 mm for 10 minutes to distill volatile cyclic siloxanes. The vacuum was released and the mixture was heated to 150 C . After cooling to room 25 temperature and filtering to remove cesium acetate, the organopolysiloxane rli~mine having a titrated molecular weight of 50,329 (50,000 theoretical) was isolated as a clear, colorless oil.

- EXAM[PLE 40 30 Preparation of a organopolysiloxane diamine from a lower molecular weight organopolysiloxane diamine WO 95/03354 ~ 3 ~ 1 PCT/US94108191--A organopolysiloxane di~mine having a theoretical molecular weight of 50,000 was prepared according to the method of Example 39 using 53.76 g of a 5000 molecular weight organopolysiloxane diamine made according to the method of Example 37, 534.48 g octamethylcyclotetrasiloxane, and 0.0125 g 5 cesium silanolate catalyst. After cooling, 0.004 grams acetic acid were added and, after the volatile cyclic siloxanes were distilled and the cesium acetate filtered, a product having a titrated molecular weight of 49,844 was obtained.

10 P,~al~tion of a organopolysiloxane diamine from a lower molecular weight organopolysiloxane ~ mine A organopolysiloxane diamine having a theoretical molecular weight of 75,000 was prepared according to the method of Example 39 using 28.67 g of a 5000 molecular weight organopolysiloxane diamine made according to the 15 method of Example 37, 441.92 g octamethylcyclotetrasili~xane, and 0.02 g cesium silanolate catalyst. After cooling, 0.009 grams acetic acid were added and, after the volatile cyclic siloxanes were distilled and the cesium acetate filtered, a product having a molecular weight of 67,982 (as measured by 29Si nmr analysis) was obtained.

Preparation of organopolysiloxane diamine using cesium hydroxide.
A solution of 0.992 g of bis(3-aminopropyl) tetramethyl disiloxane and 352 g octamethylcyclotetrasiloxane was purged with carbon dioxide for 15 min 25 and then heated to 150C; 0.06 g (100 ppm) of 50% aqueous cesium hydroxide was added and the mixture was heated to 150C for 24 hours until the aminopropyl disiloxane had been consumed. The reaction was cooled to 70C, neutralized with 0.2 g excess triethylamine and 0.06 g acetic acid, and the verythick 5 ~-d bubbly mixture was heated slowly to 150C under high vacuum to 30 remove cyclic siloxanes over a period of at least 5 hours. After all of the mixed cyclic siloxanes were distilled and collected, the product was cooled to ambient temperature and filtered to remove cesium acetate. 318 g of the WO 95/033~4 i~ ~ 6 6 3 21 PCT/US94/08191 organopolysiloxane diamine product was obtained. The titrated molecular weight of the product was 75,634 (theoretical 75,000).

EXA~PLE 43 S Preparation of a organopolysiloxane ~ mine from a lower molecular weight organopolysiloxane ~ mine A organopolysiloxane ~ mine having a theoretical molecular weight of 100,000 was prepared according to the method of Example 39, except that the reaction was run in a 94.7 liter (25 gal) stainless steel reactor, starting from 45 10 kg (6.2 lbs.) of a organopolysiloxane diamine having a molecular weight of 5000 made according to the method of Example 2, 1234.8 kg (170 lbs.) mixed dimethyl substituted cyclic siloxanes (available as "DMC Dimethyl Cyclics"
from Shin-Etsu Chemical Co.), and 16.0 g cesium hydroxide solution (for a targeted molecular weight of 100,000). After 1 hr at 150C, the reaction had 15 reached complete equilibrium and had become very viscous. The crude product was cooled to 80C, termin~tt--d with 20.0 g triethylamine and 10.0 g acetic acid, and then re-heated to 150C under high vacuum to distill volatile cyclic siloxanes. This removal of cyclics was facilitated by allowing nitrogen to bubble up from the reactor bottom during the ~ t~ tion. After 7 hours, no 20 more cyclics were collected, and the contents were cooled to ambient temperature to provide 871.7 kg (120 lbs., 68% yield) of the desired organopolysiloxane diamine having a titrated molecular weight of 100,800.

25 Preparation of a organopolysiloxane diamine from a lower molecular weight organopolysiloxane ~ mine A organopolysiloxane diamine having a theoretical molecular weight of 20,000 was prepared according to the method of Example 43. 987 g of a 5000 molecular weight organopolysiloxane diamine, 1256.7 kg (173 lbs.) mixed 30 dimethyl substituted cyclic siloxanes (available as "DMC Dimethyl Cyclics"
from Shin-Etsu Chemical Co.) and 16 g cesium hydroxide were mixed under reaction conditions. After cooling, 20 g triethylamine and 16 grams acetic acid WO 95/03354 ~ 3~ PCT/US94/08191 were added and a 29Si nmr analysis of silanol content was performed on this interme li~tP. Following this measurement, the volatile cyclic siloxanes were 1i~tillP~ and the cesium acetate filtered, a product having a titrated molecularweight of 20,000 was obtained.
s TESTING FOR SILANOL IMPURITIES
Comparison of purity of organopolysiloxane ~ mines ~,~aled using different catalysts and methods The organopolysiloxane di~mine products described in Examples 12, 10 37-44 were examined by 29Si nmr spectroscopy and recorded in Table VI. For co,l,pal~tive purposes, 29Si nmr analysis of organopolysiloxane ~ mines made by the prior art method from Example 16 have also been provided. This method was used to determine the average molecular weight, amine and silanol endgroup distribution ratios, and the relative weight percent silanol content for 15 these examples. The organopolysiloxane diamine samples were dissolved in chloroform-dl, a relaxation agent (chromium acetonyl acetonate) added, and the spectra were acquired using a Varian Unity 300 NMR spectrometer operating at 59.59 MHz. Relative integrated area ratios of the amine endgroups (-NH2) silicon peak, silanol endgroups (-SiOH) silicon peak, and the 20 poly(dimethylsiloxane) silicon peak were used to calculate the values.

WO 9~/033~4 21 ~ PCT/US94/08191 TABLE VI

Ex.Catalyst Mw Wt.%S % NH2 % -SiOH
iOH Endgroups Endgroups 16(Comp.) NMe4OH 12,043 0.019 93.8 6.2 12 NMe40Si 11,300 0.010 97.4 2.6 37 CsOSi 10,400 0.005 98.5 1.5 38 CsOH 10,491 0.006 98.2 1.8 391 CsOH 50,329 0.014 81.5 18.5 392 CsOH 50,329 0.005 92.3 7.7 CsOSi 49,844 0 100 0 41 CsOSi 67,982 0 100 0 42 CsOH 75,634 0.002 95.8 4.2 43 CsOH 100,800 0 100 0 441 CsOH 20,000 0.017 91.2 8.8 442 CsOH 20,000 0.004 97.9 2.1 1 denotes purity of organopolysiloxane diamine prior to treatment with cesium acetate salt 2 denotes purity of organopolysiloxane rli~mine following treatment with cesium 20 acetate salt "CsOSi" denotes cesium 3-aminopropyldimethyl silanolate "NMe40Si" denotes tertamethylammonium 3-aminopropyl silanolate Table VI clearly illustrates that the methods of the present invention can 25 be used to prepare novel organopolysiloxane diamines having a broad range of molecular weights and very low levels (0.010 wt. % and less) of silanol endgroups, particularly when compared to those materials made by previously known methods (Example 16). As repeatedly stressed throughout the present application, highly difunctional, high molecular weight organopolysiloxane 30 diamines are essential in preparing a variety of elastomeric compositions and, prior to the present invention, none of the known methods for producing such compounds could yield a diamine of sufficient purity to result in the superior elastomeric materials described herein.

3 2 ~ ~
WO 95/033~4 PCTIUS94/08191 While this invention has been described in connection with speci~lc embodiments, it should be understood that it is capable of further modification.The claims herein are intended to cover those variations which one skilled in the art would recognize as the chemical equivalent of what has been described 5 here.

Claims (20)

CLAIMS:

1. A method of making an organopolysiloxane diamine having a molecular weight greater than 2000 and having less than or equal to 0.010 weight % silanol impurities, comprising the steps of:
(a) combining under reaction conditions (i) an amine functional endblocker represented by the formula IX

XI

wherein;
Y is selected from the group consisting of alkylene radicals comprising 1 to 10 carbon atoms, aralkyl radicals, and aryl radicals;
D is selected from the group consisting of hydrogen, an alkyl radical of 1 to 10 carbon atoms, and phenyl, R is at least 50% methyl with the balance of the 100% or all R radicals being selected from the group consisting of a monovalent alkyl radical having 2 to 12 carbon atoms, substituted alkyl radical having from 2 to 12 carbon atoms, a vinyl radical, a phenyl radical, and a substituted phenyl radical; and x represents an integer of 1 to 150;
(ii) sufficient cyclic siloxane to obtain said organopolysiloxane diamine having a molecular weight greater than 2000;
(iii) a catalytic amount of a compound selected from the group consisting of cesium hydroxide, rubidium hydroxide, cesium silanolates, rubidium silanolates, cesium polysiloxanolates, rubidium polysiloxanolates, and mixtures thereof;
(b) continuing the reaction until substantially all of said amine functional endblocker is consumed;
(c) terminating the reaction by the addition of a volatile organic acid to form a mixture of an organopolysiloxane diamine having greater than 0.010 weight %
silanol impurities and one or more of the following: a cesium salt of the organic acid, a rubidium salt of the organic acid, both a cesium salt of the organic acid and a rubidium salt of the organic acid; wherein a molar excess of organic acid is added in relation to the compound of element (a)(iii);
(d) condensing under reaction conditions and under vacuum condition a sufficient amount of said silanol impurities to form an organopolysiloxane diamine having less than or equal to 0.010 weight % silanol impurities; and (e) optionally removing said salt.

2. The method of claim 1 wherein the endblocker has greater than 0.010 weight % silanol impurities.

3. The method of claim 1 wherein the endblocker has less than or equal to 0.010 weight % silanol impurities.

4. The method of claim 1 wherein said organopolysiloxane diamine has a molecular weight greater than 5000.

5. The method of claim 1 wherein x represents an integer of 1 to 70 and Y is selected from the group consisting of -CH2CH2CH2- and -CH2CH2CH2CH2-.

6. The method of claim 1 wherein 0.005 to 0.3 weight percent of the compound of element (a)(iii) is used based upon the total weight of the endblocker and the cyclic siloxane, and wherein said compound is selected from the group consisting of cesium silanolates, rubidium silanolates, and mixtures thereof.

7. The method of claim 1 wherein 0.005 to 1 weight percent of the compound of element (a)(iii) is used based upon the total weight of the endblocker and cyclic siloxane, and wherein said compound is selected from the group consisting of cesium hydroxide, rubidium hydroxide, and mixtures thereof.

8. The method of claim 1 wherein said volatile organic acid is selected from the group consisting of acetic acid, trimethylacetic acid, trichloroacetic acid, trifuoroacetic acid, and mixtures thereof.

9. The method of claim 1 wherein said reaction conditions of element (a) comprise a reaction temperature of 150°C to 160°C
and a reaction time of 0.5 to 2 hours.

10. The method of claim 1 wherein said reaction conditions of element (d) comprise a reaction temperature of 130°C to 160°C
and a reaction time of 4 to 8 hours and wherein the reaction is conducted under vacuum.

11. The organopolysiloxane diamine obtainable according to the method of claim 1.

12. A method of making and organopolysiloxane diamine having a molecular weight of at least 5000, and being prepared by the steps of (1) combining under reaction conditions:
(a) amine functional endblocker of the general formula where; Y is selected from the group consisting of aralkyl, and aryl radicals; D is selected from the group consisting of hydrogen, an alkyl radical of 1 to 10 carbon atoms, and phenyl;
and R is each independently selected from the group consisting of a monovalent alkyl radical having from 1 to 12 carbon atoms, a substituted alkyl radical having from 1 to 12 carbon atoms, a phenyl radical, and a substituted phenyl radical;
(b) sufficient cyclic siloxane to react with said amine functional endblocker to form an intermediate organopolysiloxane diamine having a molecular weight less than 2,000 and general formula where:
Y and D are as defined above; R is at least 50% methyl with the balance of the 100% of all R radicals being selected from the group consisting of a monovalent alkyl radical having from 2 to 12 carbon atoms, a substituted alkyl radical having from 1 to 12 carbon atoms, a vinyl radical, a phenyl radical and a substituted phenyl radical; and x is a number in the range of 4 to 40; and (c) a catalytic amount of a compound characterized by having a molecular structure represented by the formula:

where;
Y and D are as defined above; R is each independently selected from the group consisting of a monovalent alkyl radical having from 1 to 12 carbon atoms, a substituted alkyl radical having from 2 to 12 carbon atoms, a phenyl radical, and a substituted phenyl radical; and M+ is selected from the cations K+, Na+ and N(CH3)4+;
(2) continuing the reaction until substantially all of said amine functional endblocker is consumed; and (3) adding additional cyclic siloxane until said organopolysiloxane diamine having a molecular weight of at least 5000 is formed.

13. The organopolysiloxane diamine obtainable according to the method of claim 12.

14. A method of making an organopolysiloxane diamine having a molecular weight of at least 2000 and having less than or equal to 0.010 weight % silanol impurities, and being prepared by the steps of (1) combining under reaction conditions:
(a) amine fuctional endblocker of the general formula where:
Y is selected from the group consisting of an alkylene radical of 1 to 10 carbon atoms, aralkyl, and aryl radicals; D
is selected from the group consisting of hydrogen, an alkyl radical of 1 to 10 carbon atoms, and phenyl; and R is each independently selected from the group consisting of a monovalent alkyl radical having from 1 to 12 carbon atoms, a substituted alkyl radical having from 1 to 12 carbon atoms, a phenyl radical, and a substituted phenyl radical;

(b) sufficient cyclic siloxane to react with said amine functional endblocker to form an intermediate organopolysiloxane diamine having a molecular weight less than 2,000 and general formula where:
Y and D
are as defined above; R is at least 50% methyl with the balance of the 100%
of all R radicals being selected from the group consisting of a monovalent alkyl radical having from 2 to 12 carbon atoms, a substituted alkyl radical having from 1 to 12 carbon atoms, a vinyl radical, a phenyl radical and a substituted phenyl radical; and x is a number in the range of 4 to 40; and (c) a catalytic amount of a compound characterized by having a molecular structure represented by the formula:

where:
Y and D are as defined above; R is each independently selected from the group consisting of a monovalent alkyl radical having from 1 to 12 carbon atoms, a substituted alkyl radical having from 2 to 12 carbon atoms, a phenyl radical, and a substituted phenyl radical; and Q+ is selected from the cations Cs+ and Rb+;
(2) continuing the reaction until substantially all of said amine functional endblocker is consumed;
(3) adding additional cyclic siloxane in an amount required to obtain the organopolysiloxane diamine of the deiired molecular weight;
(4) terminating the reaction by addition of a volatile organic acid to form the organopolysiloxane of at least 2000 molecular weight having less than or equal to 0.010 weight percent silanol impurities; and (5) removing any residual cyclic siloxanes and volatile impurities.

15. The organopolysiloxane diamine obtainable according to the method of claim 14.

16. The method of claim 14 wherein said reaction conditions comprise a reaction temperature of 150° to 160°C and a reaction time of 0.5 to 2 hours.

17. The method of claim 14 wherein the compound of element (1) (c) is used at less than 0.025 weight percent based upon the total weight of the organopolysiloxane diamine.

18. The method of claim 14 wherein the compound of element (1) (c) is used at 0.0025 to 0.01 weight percent based upon the total weight of the organopolysiloxane diamine.

19. The method of claim 14 wherein the organopolysiloxane diamine has a molecular weight greater than 5000.

20. A compound having catalytic properties, characterized by having a molecular structure represented by the formula:

where D is selected from the group consisting of hydrogen, as alkyl radical of 1 to 10 carbon atoms, and phenyl;
Y is an alkylene radical of 1 to 10 carbon atoms;
R is each independently selected from the group consisting of a monovalent alkyl radical having from 1 to 12 carbon atoms, a substituted alkyl radical having from 2 to 12 carbon atoms, a phenyl radical, and a substituted phenyl radical; and Q+ is selected from the cations Cs+ and Rb+.