CA1195033A - Low modulus one-component rtv compositions and processes - Google Patents
Low modulus one-component rtv compositions and processesInfo
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- CA1195033A CA1195033A CA000423365A CA423365A CA1195033A CA 1195033 A CA1195033 A CA 1195033A CA 000423365 A CA000423365 A CA 000423365A CA 423365 A CA423365 A CA 423365A CA 1195033 A CA1195033 A CA 1195033A
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Abstract
Abstract A one-component alkoxy-functional RTV silicone rubber composition which is made shelf-stable by the incorporation of scavengers in the composition to absorb hydroxy groups. The present composition is made low modulus by the incorporation of various additives in the composition such as a trifunctional fluid and a linear diorganopolysiloxane fluid. There is also disclosed the use of sag control additives in the uncured composition to impart to it thixotsopic properties.
Description
5~3~ ~OSi-640 LOW MOI:)ULUS ONE-C~()NENT
Rl~ COMP05ITIONS AND PROCE~S5;E~S
_ . .
.
The presen~ invention rela~es ~o one-component ~TV
compositions and processes and more par~icularly the present invention rela~es to low modulus alkoxy functional, one-compon-ent RTV compositions and processes.
The earliest type of one~component RTV composikions were ones in which a cros~-linking ayent was an acyloxy-func tiona~ silane as disclosed in Cey2eriat, V.S. Pater3t 3~133,891 and Bruner3 U.SO Patent 3,035j016. Further, the disclosuxe of Kulpa, U.SO Patent 3,2960161, Goossens, U.S. Pat2nt 3,~96, 195 and Beers, U.S. Pa~en~ 3,438~930, relate ~o the use of certain self-bonding additives to m~ke such compositions self-bondiny. ~ile such acyloxy-functional composi~ionswere fast-curing and had other desirable properties, nevertheless they have two disad~antages. One disadvantage is that they relea~ed lS acetic acid upon curing whlch was somewhat corrosive.
Further, such acetic acid gave off an objectionahle odor such that it was somewha~ difficult to work wi~h this system with.in an enclosed envirollm~nt.
~ccordingly, it early became highly desirable to have a ~0 non-corrosive, fast-curin~, one component RTV system. The two-component ~TV sys~ems as exemplified by Nitzsche e~ al., U~ S. Patent 3 ,127, 363 were non~corxosive . Howevex, 5~
3~
60~I-6~0 compositions had to be prepared in two packages and mixed immediately prior to application of the system and once they were mixed they had to be used in a short period of time, otherwise the composition would not cure at a sufficiently fast rate. Accordingly, even though such compositions were non-corrosive, nevertheless they require additional labor cost in the application of the system, and once mixed -the system had a very poor shelf life.
An early example of such alkoxy-functional composition in the one-component form is to be found in Nitzsche et al., U.S. Patent 3,065,194 dated November 20, 1962. However such composition suffered from the fact that there has to he utilized vigorous drying in the preparation of the composi-tion, and that the composition also has a short shelf period. Other alkoxy-functional one-component RTV compositions are to be found in Brown et al., U.S. Patent 3,122,522, dated February 25, 1964, and srown et al.~ U.S. Patent 3,161,614 dated December 15, 1964 or U.S. Patent RE-29,760 dated September 12, 1978. These compositions were not ~0 sufficiently fast-curing, that is, if they cured at all, they would cure at a very slow rate especially after they had been stored for some time, that is a period of a week or more. It was found that such compositions would not cure at a sufficently fast rate with the normal condensation catalysts that were used in the acyloxy systems.
Accordingly, there was devised various titaniurn chelate catalysts for such alkoxy-functlonal, one-component RTV systems. Examples of titanium chelate catalysts in alkoxy one-component RTV systems are to be found in the disclosures of Weyenberg, ~.S. Patent 3,33~,067 dated August 1, 1967. Cooper et al., U.S.
Patent 3,542,901 and Smith et al., U.S. Patents 3,689,454 and 3,779,986 - the last two ~eing assigned to the same assignee as the present invention.
A further example of such systems which were commercialized in one form or another and particularly with various types of additives, are to be found in the disclosure of Beers, U.S. Paten-t 4,100,129 dated July 11, 1978. This latter patent discloses an alkoxy-functional, one-component RTV system as stated above, whi.ch is commercialized and particularly dependent upon a speci.fic type of chelate catalysts to give the composition a sufficient curing rate after the composition had been stored for periods of time, 6 months or more. In the disclosure of U.S. Patent 4,100,129 there is disclosed that alkoxy one-component RTV systems may have in particular a tri-functional containing polysi:Loxane fluid and a linear trimethylsiloxy dimethylpolysiloxane fluid and various types of adhesion promoters. It is disclosed .in this di.sclosure that various -types of adhesion promoters may be utilized with such alkoxy-functional, one-oomponent RTV systems such as silyl isocyanurates and other compounds. However, as stated previously, such compositions still suffer from the fact that they are not sufficiently shelf stable and they are not sufficiently feast-curing.
Another example of a somewhat non-corrosive, one-component RTV system is, for instance, to be :Eound in the di.sclosure of Beers, United States Patent Number 4,257,93~ dated ~larch 24, 19~1. This patent dis-~ 4 --closes a~ acyloxy~functional~ one~component RTV system wh~rein the acyloxy-functional cross-linking agen~ i5 pxefer-ably methyltris~2-ethylhexanoxysi.lane. It is disclosed that vaxious addi~lves may be utilized in such sys~ems such as for instance a fluid polysiloxane having a high degree o tri-or tetrafunctionality,~ a s~ular fluidaswa~ disclosed in U.S. Patent 4,100,129 as well as a dimethylpolysiloxane fluid.
In addition there is disclosed ~he presence of various additives such as adhesion promoters and other additives. While ~he lQ system of U~S~ Patent 4,257,932 was somewhat non-corrosivei nevertheless since i~ released an acid,albeit one of high molecular weight, i~ still was corrosive ancl still was not as fast curing as would be desired. Further, in particular, it should ~e noted its nature of corrosion was such that it would cause discoloration of various substrates and even be somewhat haxd to bond to substrates with varlous types of self-bonding acldi~ivesO Examples of several self-bonding addi~ives that could be utilized with such a compositlon is as for instance disclosed in the foregoing U.S. Patent 4,257, 932, as well as Mitchellt et alo9 U.s. Patent 4,273,698 which dis-closed th~ usc of various silyl fuma.rates, ~ilyl maleates, silyl succina~es and other compounds as adhesion promoters for such composi~ions zs well as for alkoxy~functional, one-component RTV syst~ms. Another disclosu.re ~t-deals~ ~
utilization of large amounts of calcium car~onate as a ~iller in such compositions so as to make them ~aintable i~
in. ~mith :et a~ U.S~ Patent 4,247,4~5. Ano~her disclosure in this area is D~ia~k, e~ ~., U.~. Pa ~ t 4,308,37~.
which relates to the prereacted reaction product of the -- 5 ~
adhesion promoter and the cross-linking agent so as to impart further shelf stability to the system. However, even with such prereacted systems of cross-linklng agent and adhesion pxomoter, such systems still suffer from shelf stabllity problems. ~nother disclosu.re which is pertinent is Wright et al., United States Patent Mumber 4,261,758 dated ~pril 14, 1981 which deals with the use of polyethers as sag control agents or as agents to make the composition thixotropic by the incorporation in the composition oE small amounts of polyethers.
Recently, there has been devi.sed a stable substan-tially acid~free, one package moisture curable poly-alkoxyterminated organopolysiloxane system having as a condensation catalyst, preferably a tin compo~md as disclosed in White et al., Canadian application Serial No.404,949 which was filed on June 11, 1982 and Halgren, Canadian application Serial Number 399,994 which was filed on March 31, 1982. Another re]evant patent application in this area is Chung, United States Patent Number ~ 7 dated J~V~"q~ which deals wit~ the utilizatl.on of a particular scavengex in such systems, and Lucas et al.., Canadian aplicat.ion Serial No filed /~
which dea].s with the utilization of vari.ous types of adhesion promoters in such systems and in the pre~erred system of the instant case. There is also the 3~
~nited States Patent No. 4,417,04~, issued November 22, 1983 to Dziark t which concerns the use o~
certain silazanes and silyl-nitrogen polymers as scavengers with a polya:Lkoxy base organopoly siloxane polymer. There are some of the scavenging systems not in the White et al caseO The scavengers and RTV system of the above-mentioned U.S. Patent 4,417,042 is preferably cured with the additives of the present case although it should be understood that -the additives of the present case can be used with any of -the RTV systems of White et al, Canadian Application Serial No. 404,949, filed January 11, 198~. Substantially, the utilization of certain scavengers i.n alkoxy-functional, one-component RTV systems so as to remove or tie up most hydroxy groups in the uncured polymer compositions, results in -the composition having good shel.f stab.ility and a good cure rate even with a tin soap catalyst. Further, the system i.s non-corrosive.
It was also desirabl.e to make such composi-tions low modulus, that is that such compositions have a low tensile strength and high elastivity so that they could be utilized in glazing and sealant applications.
especially in high-rise construction work. It was also desirable to make such composition self-bonding as was disclosed in the ~oregoing Lucas et al ~ Canadlan application Serial No. ~3, ~s ~
filed ~ ~P c~ 9 ~3 There has been a continuing search for additional self bonding additives and there has been an attempt to make such compositions as low-modulus as possible which was not the case with the basic system disclosed in White et al., Canadian application Serial Number 404,949 Eiled June 11/ 1982, which was disclosed aboveO
Accordingly, it is one object of -the present invention to provide for one-component, alkoxy-functional RTV systems, which is self-bonding by the use of novel self-bonding additives.
It is an additional object of the present invention to provide for an alkoxy-functional, one-component RTV system which is low modulus, that is, has a low tensile strength and a very high elongation.
Rl~ COMP05ITIONS AND PROCE~S5;E~S
_ . .
.
The presen~ invention rela~es ~o one-component ~TV
compositions and processes and more par~icularly the present invention rela~es to low modulus alkoxy functional, one-compon-ent RTV compositions and processes.
The earliest type of one~component RTV composikions were ones in which a cros~-linking ayent was an acyloxy-func tiona~ silane as disclosed in Cey2eriat, V.S. Pater3t 3~133,891 and Bruner3 U.SO Patent 3,035j016. Further, the disclosuxe of Kulpa, U.SO Patent 3,2960161, Goossens, U.S. Pat2nt 3,~96, 195 and Beers, U.S. Pa~en~ 3,438~930, relate ~o the use of certain self-bonding additives to m~ke such compositions self-bondiny. ~ile such acyloxy-functional composi~ionswere fast-curing and had other desirable properties, nevertheless they have two disad~antages. One disadvantage is that they relea~ed lS acetic acid upon curing whlch was somewhat corrosive.
Further, such acetic acid gave off an objectionahle odor such that it was somewha~ difficult to work wi~h this system with.in an enclosed envirollm~nt.
~ccordingly, it early became highly desirable to have a ~0 non-corrosive, fast-curin~, one component RTV system. The two-component ~TV sys~ems as exemplified by Nitzsche e~ al., U~ S. Patent 3 ,127, 363 were non~corxosive . Howevex, 5~
3~
60~I-6~0 compositions had to be prepared in two packages and mixed immediately prior to application of the system and once they were mixed they had to be used in a short period of time, otherwise the composition would not cure at a sufficiently fast rate. Accordingly, even though such compositions were non-corrosive, nevertheless they require additional labor cost in the application of the system, and once mixed -the system had a very poor shelf life.
An early example of such alkoxy-functional composition in the one-component form is to be found in Nitzsche et al., U.S. Patent 3,065,194 dated November 20, 1962. However such composition suffered from the fact that there has to he utilized vigorous drying in the preparation of the composi-tion, and that the composition also has a short shelf period. Other alkoxy-functional one-component RTV compositions are to be found in Brown et al., U.S. Patent 3,122,522, dated February 25, 1964, and srown et al.~ U.S. Patent 3,161,614 dated December 15, 1964 or U.S. Patent RE-29,760 dated September 12, 1978. These compositions were not ~0 sufficiently fast-curing, that is, if they cured at all, they would cure at a very slow rate especially after they had been stored for some time, that is a period of a week or more. It was found that such compositions would not cure at a sufficently fast rate with the normal condensation catalysts that were used in the acyloxy systems.
Accordingly, there was devised various titaniurn chelate catalysts for such alkoxy-functlonal, one-component RTV systems. Examples of titanium chelate catalysts in alkoxy one-component RTV systems are to be found in the disclosures of Weyenberg, ~.S. Patent 3,33~,067 dated August 1, 1967. Cooper et al., U.S.
Patent 3,542,901 and Smith et al., U.S. Patents 3,689,454 and 3,779,986 - the last two ~eing assigned to the same assignee as the present invention.
A further example of such systems which were commercialized in one form or another and particularly with various types of additives, are to be found in the disclosure of Beers, U.S. Paten-t 4,100,129 dated July 11, 1978. This latter patent discloses an alkoxy-functional, one-component RTV system as stated above, whi.ch is commercialized and particularly dependent upon a speci.fic type of chelate catalysts to give the composition a sufficient curing rate after the composition had been stored for periods of time, 6 months or more. In the disclosure of U.S. Patent 4,100,129 there is disclosed that alkoxy one-component RTV systems may have in particular a tri-functional containing polysi:Loxane fluid and a linear trimethylsiloxy dimethylpolysiloxane fluid and various types of adhesion promoters. It is disclosed .in this di.sclosure that various -types of adhesion promoters may be utilized with such alkoxy-functional, one-oomponent RTV systems such as silyl isocyanurates and other compounds. However, as stated previously, such compositions still suffer from the fact that they are not sufficiently shelf stable and they are not sufficiently feast-curing.
Another example of a somewhat non-corrosive, one-component RTV system is, for instance, to be :Eound in the di.sclosure of Beers, United States Patent Number 4,257,93~ dated ~larch 24, 19~1. This patent dis-~ 4 --closes a~ acyloxy~functional~ one~component RTV system wh~rein the acyloxy-functional cross-linking agen~ i5 pxefer-ably methyltris~2-ethylhexanoxysi.lane. It is disclosed that vaxious addi~lves may be utilized in such sys~ems such as for instance a fluid polysiloxane having a high degree o tri-or tetrafunctionality,~ a s~ular fluidaswa~ disclosed in U.S. Patent 4,100,129 as well as a dimethylpolysiloxane fluid.
In addition there is disclosed ~he presence of various additives such as adhesion promoters and other additives. While ~he lQ system of U~S~ Patent 4,257,932 was somewhat non-corrosivei nevertheless since i~ released an acid,albeit one of high molecular weight, i~ still was corrosive ancl still was not as fast curing as would be desired. Further, in particular, it should ~e noted its nature of corrosion was such that it would cause discoloration of various substrates and even be somewhat haxd to bond to substrates with varlous types of self-bonding acldi~ivesO Examples of several self-bonding addi~ives that could be utilized with such a compositlon is as for instance disclosed in the foregoing U.S. Patent 4,257, 932, as well as Mitchellt et alo9 U.s. Patent 4,273,698 which dis-closed th~ usc of various silyl fuma.rates, ~ilyl maleates, silyl succina~es and other compounds as adhesion promoters for such composi~ions zs well as for alkoxy~functional, one-component RTV syst~ms. Another disclosu.re ~t-deals~ ~
utilization of large amounts of calcium car~onate as a ~iller in such compositions so as to make them ~aintable i~
in. ~mith :et a~ U.S~ Patent 4,247,4~5. Ano~her disclosure in this area is D~ia~k, e~ ~., U.~. Pa ~ t 4,308,37~.
which relates to the prereacted reaction product of the -- 5 ~
adhesion promoter and the cross-linking agent so as to impart further shelf stability to the system. However, even with such prereacted systems of cross-linklng agent and adhesion pxomoter, such systems still suffer from shelf stabllity problems. ~nother disclosu.re which is pertinent is Wright et al., United States Patent Mumber 4,261,758 dated ~pril 14, 1981 which deals with the use of polyethers as sag control agents or as agents to make the composition thixotropic by the incorporation in the composition oE small amounts of polyethers.
Recently, there has been devi.sed a stable substan-tially acid~free, one package moisture curable poly-alkoxyterminated organopolysiloxane system having as a condensation catalyst, preferably a tin compo~md as disclosed in White et al., Canadian application Serial No.404,949 which was filed on June 11, 1982 and Halgren, Canadian application Serial Number 399,994 which was filed on March 31, 1982. Another re]evant patent application in this area is Chung, United States Patent Number ~ 7 dated J~V~"q~ which deals wit~ the utilizatl.on of a particular scavengex in such systems, and Lucas et al.., Canadian aplicat.ion Serial No filed /~
which dea].s with the utilization of vari.ous types of adhesion promoters in such systems and in the pre~erred system of the instant case. There is also the 3~
~nited States Patent No. 4,417,04~, issued November 22, 1983 to Dziark t which concerns the use o~
certain silazanes and silyl-nitrogen polymers as scavengers with a polya:Lkoxy base organopoly siloxane polymer. There are some of the scavenging systems not in the White et al caseO The scavengers and RTV system of the above-mentioned U.S. Patent 4,417,042 is preferably cured with the additives of the present case although it should be understood that -the additives of the present case can be used with any of -the RTV systems of White et al, Canadian Application Serial No. 404,949, filed January 11, 198~. Substantially, the utilization of certain scavengers i.n alkoxy-functional, one-component RTV systems so as to remove or tie up most hydroxy groups in the uncured polymer compositions, results in -the composition having good shel.f stab.ility and a good cure rate even with a tin soap catalyst. Further, the system i.s non-corrosive.
It was also desirabl.e to make such composi-tions low modulus, that is that such compositions have a low tensile strength and high elastivity so that they could be utilized in glazing and sealant applications.
especially in high-rise construction work. It was also desirable to make such composition self-bonding as was disclosed in the ~oregoing Lucas et al ~ Canadlan application Serial No. ~3, ~s ~
filed ~ ~P c~ 9 ~3 There has been a continuing search for additional self bonding additives and there has been an attempt to make such compositions as low-modulus as possible which was not the case with the basic system disclosed in White et al., Canadian application Serial Number 404,949 Eiled June 11/ 1982, which was disclosed aboveO
Accordingly, it is one object of -the present invention to provide for one-component, alkoxy-functional RTV systems, which is self-bonding by the use of novel self-bonding additives.
It is an additional object of the present invention to provide for an alkoxy-functional, one-component RTV system which is low modulus, that is, has a low tensile strength and a very high elongation.
2() It is still an additional object o~ the present invention to make one-component RTV systems wh:ich are substantially noncorrosive, shel F stable, and which have a low modulus.
It i.s still a further object o:E the present invention to make a low cost one-component RTV com-position that is low modulus by incorporating various ingrc-~dients i.ll tO the composition.
~O~i-64 It is still fur~her an addi~ional ob~ec~ of the present invention to provide a process for producin~ a one~com2onent R~V system whioh is non-corrosive, low modulus, low cos~ and îs shelf stable.
These and other objects of ~he present inven~ion are accomplished by means of the disclosures set forth ~ ~m~
.
Summary of the_Invention -In accordance with ~he above objec~s, there is provided by th~e present i~vention a stable, one package, substantially anhydrous and substan~ially acid-free, room temperature vul-canizable organo~olysiloxane composition sta~le under ambient conditions .in the substantial absence of moisture over an ex-tended period of time and convertible to a tack-free elastomer comprising: (1) an organopol~siloxane wherein the silicon atorn at each polymer chain end is ~erminated with at least 2 alkoxy radicals; (2~ an effective amount of a condensation catalyst; (3) a s~abilizin~ amoun~ of silane scavenger fo.r hydroxy functional groups having the formula, [R )c (R )~O(c~ Si(X)f where ~ is a C(l 8) aliphatic or~anic radical ~elected from the grou~ consisting of alkyl, alkylether, alkylester, alkyl-ketone, and alkylcyano radicals, or a C(7 ~3) aralXyl radical, R2 is a C(l 13) monovalent substituted or unsubstituted h~dro-carbon radical, X is a hydrolyzable leaving group selected from the ~roup consisting of amido, amino, carbamato, enoxy, -- ,~
5~;~3 imidato, isocyanato, oximato, thioisocyanate and ureido radicals, and c is a whole number e~ual to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c + f is equal to 1 to 4 inclusive, and (4) where X is enoxy or amido an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, and (5) from 2 to 20 parts by weight pex 100 parts by weight of said organopoly~iloxane of a first plasticizer fluid polysiloxane containing a high degree of tri-functionality and mixtures of tri- and tetra-Eunctionality and comprising:
(i) from 5 to 60 mole percent of mono-alkylsiloxy units or siloxy units or a mixture of suchunits;
(ii) from 1 to 6 mole percent of tri.alkyl-siloxy units and (iii) from 34 to 9~ mole percent of dialkyl siloxy units, said polysiloxane containing from about 0~1 to about 2% by weight of silicone-bonded hydroxyl groups.
The basic ingredi.ent in such compositions is a polyalkoxy-functional diorganopolysiloxane pol.ymer, which is preEerably produced first by reacting a tri-a:Lkoxy silane cross-lin]cing agent such as methyl-trimethoxysilane with a silanol terminated diorgano-polysiloxane polymer. Then af-ter the two are reacte~, pre:Eerably i.n the presence of a condensation catalyst such as hexylamine there is added a scavenger to the system to absorb all the free hydroxy groups, Eor instance, methanol and then such scavengers act to absorb all the filanol groups and hydroxy groups in the additives 5~33 - 10 - 6osI-64o that were added to the basic composition. As a result, the composition is shelf-stable~
~urt~.ter~ by the addi~ion of the ingredients dis-closed in this application, the composition can be made self-bonding and low modulus as well as thixotxopic. Al-ternatively, this system may be made by mixinq a silanol polymer with a cross-linkin~ agent and ~cavenger at the ~ame time along with o~her ingredients. However~ it is found that a faster curing more shelf-stable system is made by first prereacting the silanol polymer with the cross-linkir.tg a~en~ to make the polyalkoxysilane organo-polysiloxane and then adding the scavenger to react with residual silanol aroups, moisture, and methanol, a~d then adding the other ingredients. Howe~er, if the optim~lm shelf stability pro~erties and the fast-curing properties are not desired, ther.t the other mixing procedures dis-closed in the White et al. Canadian application S.N.
No.404 r 949 E.iled June l:L, 19~2, D~scr~ti of Preferred Embodiment The base component in the RTV compositions of the present case (RTV in this ap~lication refers to .room ~.emperatuxe vulcanizabl~3 comprises a silanol telminated diorganopolysiloxane polymer and preferably one having the formula HO - ~ sio ~ . H (2) where R is a C(1-13) monovalent substituted or un-substituted hydrocaxbon :radical, which is preferably selected from alkyl radicals of 1 to 8 carbon atoms such as methyl or a mixture of a major amount of methyl and a minor amount of phenyl, cyanoethyl, triEluoro-1.5 propyl, vinyl, and mixtures thereof and n is an integer having a value of from about 50 to about 2500. Such a s.ilanol polymer may be made by various techniques such as a method of Peterson, United States Patent 4,250,290 dated February 10, 1981. Other methods are disclosed, for instance in Lampe, U.S. Patent Number 3,888,815 dated June 10, 1975. Since such polymers are well ]cnown, more detail will not be given as to their preparation~ I'here are several definitions used in the present applications such as stable, substanti.ally acidfree, etc.
As utilized hereinafter, the term "stable" as appliecl~o the one-package polyalkoxy-terminated o.rganopolysiloxane RTV's of the present invention means a moisture - ~ ( curable mixture capable of remaining substantially un-changed while excluded from atmospheric moisture and which cures to a tack-free elastomer after an extended shelf period. In addition, a stable RTV also means that the tack~free time exhibited by freshly mixed RTV in-gredients under atmospheric conditions will be sub-stantially the same as that exhibited by the same mix-tur2 o~ ingredients exposed to atmospheric moisture after having been held in a moisture resistan~ and moisture fre~ container or an ex~ended shelf period at ambient condition~, or an equi~alent period based on aecelera~ted aging at an elevated temperature.
The expression "substantially acid-free" with respect to defining ~he elast~mer made from ~he RTV
composition of the present invention upon exposure to at.mospheric moisture, means yielding by-products having a pKa o 5.5 or greater with 6 or greater preferred and 10 or greater being particularly preferred.
PrefeIably, the silanol terminated diorganopoly~
siloxane polymer that is utilized in the present in~en-t:ion, whether an alkoxy-terminated polymer or not has a viscosity that varies from 60,000 to 500,000 centipoise at 25C.
33 ~ :
The present invention i5 based on the discovery of the addi ives for a stable, substan~lally acid~free one package, moisture curable polyalkoxy~termina~ed organo-polysiloxane RTV compositions which can ~P made by using a S silanol terminated polydiorganosiloxane consisting essen tially o chemically combined diorganosiloxy units of the formula SiO - ~3 R
such as silanol-texminated ?olydiorganosiloxane of Formula (2) where R is as previously defined, with an effectiv~ amoun~ of certain silane scavengers for chemically combined hydroxy radicals. In the silanol-termj.na~ed polydioxganosiloxane consistin~ essentially o~ chemically combined Formula g3) units the presence of silicon bonded C~l 8~ alkoxy radicals such as a methoxy radical i5 not precluded. The hydroxy radicals which can be removed by the silane scavenqer can be found in materials normally present in the ~TV composition of the pxesent invention for example trace amounts of water me~hanol silanol radicals on the silica filler (if .~ 33 used), the silanol pslymer of Formula ~2~ t or a silanol-terminated ~olymex having Formula (3~ units. The sil~ne scavenger useful or eliminating chemically co~bined hydroxy radicals in accordance with the ,~ractice of the in-vention preferably has the formula, (R2 ) (R o)4_~a+D~ Si(X)a where Rl is a C(l 8) aliphatic organic rac3ical selected ~rom alkyl radicals, alkyle~her radicals, ~lkylester radicals, alkylketone radicals and alkylcyano ar a C~7 133 aralkyl radical~ R2 is a C(l 13) mono~alent organic radical selected from R radicals as previously defined, and defined more par~
ticularly helow, X i5 a hydrolyzable leaving group selected from amido, aminoV carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato, and ureido radic~ls. The preferred members are ~ ~, amido, enoxy, such as .
for example, N-C(l ~) alkyl C(l 8) 3cylamido, a is an integer equal ~o l or 2 and ~referably l, b is a whole number equal to 0 or l and the sum of a -~ h is equal to l or 20 ~n Formula (4), where a is 2~ X can be the same or ~iffer-erlt. The l~aving group X reacts Dreferentially before -O
with available -OH in the RTV composition and ~rovides an RTV composition subs~antially free of halogen acid, or car-boxylic acid. mhe silane scavenger of Formula ~4~ is both the silane sc~venger for hydroxy functional groups and a polyalkoxysilane cross-linking agent fOE ~rminating the c the silicon a oms at each organopolysiloxane chain~end wi~h at least two alkoxy radicalsO
Ano~her way of expressing the foregoing inventlon i5 by defining ~he base polyalkoxy polymers. According-ly, among the ingredients of the present RTV composi-tions which are formed as a result of the use of the hydroxy scavenger cf Formula {4~, is silanol-free poly-diorganosiloxane, chain-terminated wi~h two or ~hree ~oRl radicals. The silanol-free polydiorganosiloxane optionally can be combined with an effective amount of a cxoss~linking silane, as deined hereinafter, under substantially anhydrous conditionS. The cross-linking polyalkoxysilane which can be utilized in combination with the scavenging silane of Formula i4) ha~ the formula, (R ~ (5) (R ~b where Rl, R2 and b are as pr~viously defined. The pre ferred condensation catalysts which can be used in the practice of the invention include metal compounds selected f~om tin compounds, zirconium compounds~ and titanium compounds or mixtures thereof. ~dditiorlal condensation catalysts which can be used are defined more particularly hereinafter.
It is not compl~tely understood why thP polyalkoxy--terminated organopolysiloxane composi~ions o ~he present invention are stable in the pres~nce of cer~ain conden-sation catalysts over an ext nded period of time in ~n~
substantial absence of moisture.
-
It i.s still a further object o:E the present invention to make a low cost one-component RTV com-position that is low modulus by incorporating various ingrc-~dients i.ll tO the composition.
~O~i-64 It is still fur~her an addi~ional ob~ec~ of the present invention to provide a process for producin~ a one~com2onent R~V system whioh is non-corrosive, low modulus, low cos~ and îs shelf stable.
These and other objects of ~he present inven~ion are accomplished by means of the disclosures set forth ~ ~m~
.
Summary of the_Invention -In accordance with ~he above objec~s, there is provided by th~e present i~vention a stable, one package, substantially anhydrous and substan~ially acid-free, room temperature vul-canizable organo~olysiloxane composition sta~le under ambient conditions .in the substantial absence of moisture over an ex-tended period of time and convertible to a tack-free elastomer comprising: (1) an organopol~siloxane wherein the silicon atorn at each polymer chain end is ~erminated with at least 2 alkoxy radicals; (2~ an effective amount of a condensation catalyst; (3) a s~abilizin~ amoun~ of silane scavenger fo.r hydroxy functional groups having the formula, [R )c (R )~O(c~ Si(X)f where ~ is a C(l 8) aliphatic or~anic radical ~elected from the grou~ consisting of alkyl, alkylether, alkylester, alkyl-ketone, and alkylcyano radicals, or a C(7 ~3) aralXyl radical, R2 is a C(l 13) monovalent substituted or unsubstituted h~dro-carbon radical, X is a hydrolyzable leaving group selected from the ~roup consisting of amido, amino, carbamato, enoxy, -- ,~
5~;~3 imidato, isocyanato, oximato, thioisocyanate and ureido radicals, and c is a whole number e~ual to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c + f is equal to 1 to 4 inclusive, and (4) where X is enoxy or amido an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, and (5) from 2 to 20 parts by weight pex 100 parts by weight of said organopoly~iloxane of a first plasticizer fluid polysiloxane containing a high degree of tri-functionality and mixtures of tri- and tetra-Eunctionality and comprising:
(i) from 5 to 60 mole percent of mono-alkylsiloxy units or siloxy units or a mixture of suchunits;
(ii) from 1 to 6 mole percent of tri.alkyl-siloxy units and (iii) from 34 to 9~ mole percent of dialkyl siloxy units, said polysiloxane containing from about 0~1 to about 2% by weight of silicone-bonded hydroxyl groups.
The basic ingredi.ent in such compositions is a polyalkoxy-functional diorganopolysiloxane pol.ymer, which is preEerably produced first by reacting a tri-a:Lkoxy silane cross-lin]cing agent such as methyl-trimethoxysilane with a silanol terminated diorgano-polysiloxane polymer. Then af-ter the two are reacte~, pre:Eerably i.n the presence of a condensation catalyst such as hexylamine there is added a scavenger to the system to absorb all the free hydroxy groups, Eor instance, methanol and then such scavengers act to absorb all the filanol groups and hydroxy groups in the additives 5~33 - 10 - 6osI-64o that were added to the basic composition. As a result, the composition is shelf-stable~
~urt~.ter~ by the addi~ion of the ingredients dis-closed in this application, the composition can be made self-bonding and low modulus as well as thixotxopic. Al-ternatively, this system may be made by mixinq a silanol polymer with a cross-linkin~ agent and ~cavenger at the ~ame time along with o~her ingredients. However~ it is found that a faster curing more shelf-stable system is made by first prereacting the silanol polymer with the cross-linkir.tg a~en~ to make the polyalkoxysilane organo-polysiloxane and then adding the scavenger to react with residual silanol aroups, moisture, and methanol, a~d then adding the other ingredients. Howe~er, if the optim~lm shelf stability pro~erties and the fast-curing properties are not desired, ther.t the other mixing procedures dis-closed in the White et al. Canadian application S.N.
No.404 r 949 E.iled June l:L, 19~2, D~scr~ti of Preferred Embodiment The base component in the RTV compositions of the present case (RTV in this ap~lication refers to .room ~.emperatuxe vulcanizabl~3 comprises a silanol telminated diorganopolysiloxane polymer and preferably one having the formula HO - ~ sio ~ . H (2) where R is a C(1-13) monovalent substituted or un-substituted hydrocaxbon :radical, which is preferably selected from alkyl radicals of 1 to 8 carbon atoms such as methyl or a mixture of a major amount of methyl and a minor amount of phenyl, cyanoethyl, triEluoro-1.5 propyl, vinyl, and mixtures thereof and n is an integer having a value of from about 50 to about 2500. Such a s.ilanol polymer may be made by various techniques such as a method of Peterson, United States Patent 4,250,290 dated February 10, 1981. Other methods are disclosed, for instance in Lampe, U.S. Patent Number 3,888,815 dated June 10, 1975. Since such polymers are well ]cnown, more detail will not be given as to their preparation~ I'here are several definitions used in the present applications such as stable, substanti.ally acidfree, etc.
As utilized hereinafter, the term "stable" as appliecl~o the one-package polyalkoxy-terminated o.rganopolysiloxane RTV's of the present invention means a moisture - ~ ( curable mixture capable of remaining substantially un-changed while excluded from atmospheric moisture and which cures to a tack-free elastomer after an extended shelf period. In addition, a stable RTV also means that the tack~free time exhibited by freshly mixed RTV in-gredients under atmospheric conditions will be sub-stantially the same as that exhibited by the same mix-tur2 o~ ingredients exposed to atmospheric moisture after having been held in a moisture resistan~ and moisture fre~ container or an ex~ended shelf period at ambient condition~, or an equi~alent period based on aecelera~ted aging at an elevated temperature.
The expression "substantially acid-free" with respect to defining ~he elast~mer made from ~he RTV
composition of the present invention upon exposure to at.mospheric moisture, means yielding by-products having a pKa o 5.5 or greater with 6 or greater preferred and 10 or greater being particularly preferred.
PrefeIably, the silanol terminated diorganopoly~
siloxane polymer that is utilized in the present in~en-t:ion, whether an alkoxy-terminated polymer or not has a viscosity that varies from 60,000 to 500,000 centipoise at 25C.
33 ~ :
The present invention i5 based on the discovery of the addi ives for a stable, substan~lally acid~free one package, moisture curable polyalkoxy~termina~ed organo-polysiloxane RTV compositions which can ~P made by using a S silanol terminated polydiorganosiloxane consisting essen tially o chemically combined diorganosiloxy units of the formula SiO - ~3 R
such as silanol-texminated ?olydiorganosiloxane of Formula (2) where R is as previously defined, with an effectiv~ amoun~ of certain silane scavengers for chemically combined hydroxy radicals. In the silanol-termj.na~ed polydioxganosiloxane consistin~ essentially o~ chemically combined Formula g3) units the presence of silicon bonded C~l 8~ alkoxy radicals such as a methoxy radical i5 not precluded. The hydroxy radicals which can be removed by the silane scavenqer can be found in materials normally present in the ~TV composition of the pxesent invention for example trace amounts of water me~hanol silanol radicals on the silica filler (if .~ 33 used), the silanol pslymer of Formula ~2~ t or a silanol-terminated ~olymex having Formula (3~ units. The sil~ne scavenger useful or eliminating chemically co~bined hydroxy radicals in accordance with the ,~ractice of the in-vention preferably has the formula, (R2 ) (R o)4_~a+D~ Si(X)a where Rl is a C(l 8) aliphatic organic rac3ical selected ~rom alkyl radicals, alkyle~her radicals, ~lkylester radicals, alkylketone radicals and alkylcyano ar a C~7 133 aralkyl radical~ R2 is a C(l 13) mono~alent organic radical selected from R radicals as previously defined, and defined more par~
ticularly helow, X i5 a hydrolyzable leaving group selected from amido, aminoV carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato, and ureido radic~ls. The preferred members are ~ ~, amido, enoxy, such as .
for example, N-C(l ~) alkyl C(l 8) 3cylamido, a is an integer equal ~o l or 2 and ~referably l, b is a whole number equal to 0 or l and the sum of a -~ h is equal to l or 20 ~n Formula (4), where a is 2~ X can be the same or ~iffer-erlt. The l~aving group X reacts Dreferentially before -O
with available -OH in the RTV composition and ~rovides an RTV composition subs~antially free of halogen acid, or car-boxylic acid. mhe silane scavenger of Formula ~4~ is both the silane sc~venger for hydroxy functional groups and a polyalkoxysilane cross-linking agent fOE ~rminating the c the silicon a oms at each organopolysiloxane chain~end wi~h at least two alkoxy radicalsO
Ano~her way of expressing the foregoing inventlon i5 by defining ~he base polyalkoxy polymers. According-ly, among the ingredients of the present RTV composi-tions which are formed as a result of the use of the hydroxy scavenger cf Formula {4~, is silanol-free poly-diorganosiloxane, chain-terminated wi~h two or ~hree ~oRl radicals. The silanol-free polydiorganosiloxane optionally can be combined with an effective amount of a cxoss~linking silane, as deined hereinafter, under substantially anhydrous conditionS. The cross-linking polyalkoxysilane which can be utilized in combination with the scavenging silane of Formula i4) ha~ the formula, (R ~ (5) (R ~b where Rl, R2 and b are as pr~viously defined. The pre ferred condensation catalysts which can be used in the practice of the invention include metal compounds selected f~om tin compounds, zirconium compounds~ and titanium compounds or mixtures thereof. ~dditiorlal condensation catalysts which can be used are defined more particularly hereinafter.
It is not compl~tely understood why thP polyalkoxy--terminated organopolysiloxane composi~ions o ~he present invention are stable in the pres~nce of cer~ain conden-sation catalysts over an ext nded period of time in ~n~
substantial absence of moisture.
-
3~
It is believed that the reason that the compositions of White et al., Canadian application Serial No.404,949 filed January ll, 1982 are stable is the fact that the scavenger ties up all hydroxy groups in the ~TV system such that there are no free hydroxy groups in the system which can further cross-link the uncured polymer so as to increase its viscosity and decrease its shelf llfe while it ls being stored. Further, such free hydroxy g:roups may tend to degrade and degenerate further the alkoxy polymer in the package during storage in various ways.
The use of the silane scavenger for hydroxy of E'ormulas (l) or (4), in which the leaving group X
is not a halogen radical, substan-tially eliminates undesirable water in the filler and silicone polymer, as well as residual moisture in the RTV composition during the shelf period. In determining what level of silane scavenger of Formula (l) or (4) to use in the practice of the invention, the total hydroxy Eunctionality of the RTV composition can be estimated.
The total hydroxy Eunctionality o~ the polymer can be determined by infrared analysis. In order to insure that an e:Efective or stabilizing amount of scavenger is used to maintain the stability o:E the composition over an extended shelf period of six months or more at ambient temperature while in a sealed container, there can be used an additional amount of scaven~er over that amount required to end-stop the polymer.
This excess o~ scavenger can be up to about 3% by weight, based on the weight of the polymer. The aforementioned 3% of scavenger by weight exceeds ~ c c 3~
that amount required to substantially eliminate available hydroxy functionality in the polymer as a result of reaction between OH functionality and X radicalsO ~n compositions which also contain filler an(3 o~her addi~ives, the additional amount of scavenger of Formulas (13 or (4) which is re~uired is estimated by running a 48-hour stability check at 100C.
to determine whether the tack-free time remairls substantially u.nchan~ed as compared to the tacli-free tim~ of the com~osition beore aging measured under substantially the same cond tions.
Where polyalkoxy-terminated polymer of Formula ~
below is made withouk usin~ silane scavenger of Formula ~4), silane scavenger can be used in the practice of the invention having less than two ~ORl radicals attached ~o silicon, as shown by the formula, (R ~c (R )4-(c~d) SiXd where Rl, R~, and X are as oreviously defin~d, c is a whole number e~ual to 0 to 3 inclusive, d is an inte~er equal to 1 to 4 lnclusive, and the sum of (c + d) i5 equal to 3 or
It is believed that the reason that the compositions of White et al., Canadian application Serial No.404,949 filed January ll, 1982 are stable is the fact that the scavenger ties up all hydroxy groups in the ~TV system such that there are no free hydroxy groups in the system which can further cross-link the uncured polymer so as to increase its viscosity and decrease its shelf llfe while it ls being stored. Further, such free hydroxy g:roups may tend to degrade and degenerate further the alkoxy polymer in the package during storage in various ways.
The use of the silane scavenger for hydroxy of E'ormulas (l) or (4), in which the leaving group X
is not a halogen radical, substan-tially eliminates undesirable water in the filler and silicone polymer, as well as residual moisture in the RTV composition during the shelf period. In determining what level of silane scavenger of Formula (l) or (4) to use in the practice of the invention, the total hydroxy Eunctionality of the RTV composition can be estimated.
The total hydroxy Eunctionality o~ the polymer can be determined by infrared analysis. In order to insure that an e:Efective or stabilizing amount of scavenger is used to maintain the stability o:E the composition over an extended shelf period of six months or more at ambient temperature while in a sealed container, there can be used an additional amount of scaven~er over that amount required to end-stop the polymer.
This excess o~ scavenger can be up to about 3% by weight, based on the weight of the polymer. The aforementioned 3% of scavenger by weight exceeds ~ c c 3~
that amount required to substantially eliminate available hydroxy functionality in the polymer as a result of reaction between OH functionality and X radicalsO ~n compositions which also contain filler an(3 o~her addi~ives, the additional amount of scavenger of Formulas (13 or (4) which is re~uired is estimated by running a 48-hour stability check at 100C.
to determine whether the tack-free time remairls substantially u.nchan~ed as compared to the tacli-free tim~ of the com~osition beore aging measured under substantially the same cond tions.
Where polyalkoxy-terminated polymer of Formula ~
below is made withouk usin~ silane scavenger of Formula ~4), silane scavenger can be used in the practice of the invention having less than two ~ORl radicals attached ~o silicon, as shown by the formula, (R ~c (R )4-(c~d) SiXd where Rl, R~, and X are as oreviously defin~d, c is a whole number e~ual to 0 to 3 inclusive, d is an inte~er equal to 1 to 4 lnclusive, and the sum of (c + d) i5 equal to 3 or
4. In such situations, the scavengln~ silanes of Formula ~0 ~6) can be used in an amount sufficient to stabilize the R~V
comoosition as ~reviously defined for the scavenging silane of Formula ~41. In additio~, there can be used w' th scavengers of Formulas (4) or (6~ at least 0.01 ?art and up to 10 parts of the cross lin~in~ silane of Formula ~5~.
~5~33 ~ 18 - 60SI-640 The polyalkoxy-terminated organopolysiloxane of the present invention has the formula (R )b ~ R ~ sl(OR )3 (b-~e) (7) Xe R Xe where R, R , R , X, n and b are as previously defined and e i.s equal to 0 to 1 and the sum of b + e is equal to 0 to 1. The polyalkoxy-terminated organopolysiloxane of Formula (7), can be made by various procedures. One procedure is taught by Cooper et al, U.S. Patent 3,542,901, issued November ~4, lg70, involving the use of a polyalkoxysilane with a silanol-terminated polydiorganosiloxane in the presence of an amine catalyst as discussed above.
A method no-t taught by Cooper et al is the use o:E the silane scavenger of Formula (4) as an end-capper with silanol-terminated polydiorgano-siloxane used i.n the practice of the invention.
The additives of the present case are pre.ferably used where the polyalkoxy diorganopolysiloxane of Formula (7~ is first formed and then the additives are added.
In Formulas (1-7) J R is preferably selected from C(l 13) monovalent hydrocarbon radicals, halogerlated hydrocarbon radicals and cyano alkyl radicals, Rl is preferably a C(l 8) alkyl radical or a C(7-13) aralkyl radical, R2 i5 preferably methyl, phenylg or vinyl.
The preferxed X radicals in Formulas ~3), ~5)0 and t61 are amido, amino and enoxy, and ~h most pre-ferred is amidoO
It has been further found that improved cure rates can be achieved if minor amoun~s of amines, sub-stituted guanidines, or mixtures thereof, are utilized as curing accelera~ors in the polyalkoxy compositions of the present invention. Ihese curing accelera~ors also serve to catalyse the ability of the enoxy leaving group to act a~ a scavenger. There can be used from O~l to 5 parts, and preferably from abou~ .3 to l part of curing accelerator, per lO0 parts of the silanol-terminated polymer of Formula (2), or which consists of chemically combined units of Formula ( 3 ), or lO0 parts of the polyalkoxy-terminated polymer of ~ormula (7) to substantially reduce the tack~free time ~TFT) of the RTV composition of the present invention. This enhanced cure rate i5 maintained after it has been ~0 a~ed ~or an extended shelf period, for example 6 months or more at an~ient temperatures, or a comparable period uncler acceleratecl aging condi~ions~ Its cure proper-ties after the extended shelf period will be sub stantially similar to its initial cure propertiesg for example, tac~fre~ ~ime ~TFT), shown by the RTV composl-tion upon bein~ freshly mlx d and im~ediately exposed to atmospheric moisture.
It appears -that the curing accelerators described herein, in addition to decreasin~ the tack-free times of the RTV compositions of this invention, also provide a surl?rising stabilizing e:Efect for paxticular P~TV compo-SitionS ::atalyzed wi~ch cer~ain corldensatioll ca~alysts which exhi~i~ a marked len~theniny of tack-free time after 1~ accelerated aging. For this class of condensation cata-lysts, addition of amines, substi~u~ed g~anidines and mixtures thereof described herein provide stable RTV
compositions which exhibit ~ fast cur~ rate initially, i.e., less than about 30 minutes which remains sub-stantially unchan~ed after accelerated aging.
The RTV compositions of the present invention can cuxe to a depth of abol~t 1~8" thickness within 24 hours. Durometer Hardness (5hore ~) can then be deter-mined and used ~o evaluate the cure of the compositions 2~ as shown in the examples.
;~ 3~
A general way of stat ng the polymer system of White e~ al~ is tha~ there is present a one-package subs~antially anhydrous room ~emperature vulcanizable organopolysiloxane composi~ion stable under ambient conditions in the substantial ab-sence of moisture over an extended pexiod of time ~nd convertible to a substantially acid~free, tack-free elastomer comprising~ an organopolysiloxane where~
in the .silicon atom at each polymer chain end is ter-minated with at least two alkoxy radicals, (2~ an ef-fective amount of condensation catalyst; and (33 a stabilizing amount of scavenging silane of the formula, (Rl) ~, (C ~) S;X~
~here R , R2, X and c are as previously deined, f is lS all integer equal to 1 to 4 inclusive, and the sum of c + ~ is ~ual to 1 to 4 i.nclusj.ve. In addition, an effective amount of a curin~ accelerator selec~ed from substituted guanidines, amines and mixtures thereof is used.
In a fu~ther asp~ct of the present invention/ there is provided a s~able room ~emp~rature vulcani~able poly~
.~ 3~
alkcxy-terrnina~ed organopolysiloxane composition curable under ambient condi ions ~o a ~ack-free, subs~antially acid-free el as komer compri sing:
(A) 100 parts o a polyalkoxy-terminate~ organor poiysiloxane of Formula ( 7 );
(B~ O to 10 parts of a cross linking silane of Formula ( 5 );
(C) an efective amount of condensatlon catal~st; and ~D~ a ~ta~ilizin~ amount of scavenging silane of Formul~
Also included within the scope of the presen~ case is a method of making a room temperatuxe vulcanizable organo-polysiloxane composition under subs~antially anhydrous con~
ditions utilizin~ an effective amount of a condensation lS catalyst with a silanol-terminated organopolysiloxane and a polyalkGxysilane cross linking ayent, the improvement which comprises: (1) adding to the silano.l-terminated organopolysiloxane a sta~ilizing amount of a polyalkoxy-silane which i5 both a scavenger for hydroxy functional groups and a cxoss linking a~ent of the formula, (~2)b ~ )4-~b+a) Sl(X)a where Rl, R2, X~ a and b are as previously defined, and thereater adding an efective amount of a condensatio-catalyst, whereby improved sta~ y is ach-eved in the ~S resul~ing room tempera~ure ~Julcani~able organopolysiloxane compositions.
Another method of the present case is making a room temperature vulcanizable organopolysiloxane composition under subs~.antially anhydrous conditions u~ilizing an ef-fective amount of a condensation ca~alyst wit~ an organo~
polysiloxane wherein the silicon atom at each polymer chain cnd is terminated with at leas~ two alkoxy radicals/ which involv~s the improvement which comprises addiny to said polyalkoxy-terminated organopolysiloxane (1) a ~tabilizing amQunt of a silane scavenger for hydroxy functional groups of the formula, ( 12) C
(~lo~4-(c+~Si(X)f where R , R , X, c and f are as previously defined and (2) an effective amount of a condensation catalyst, whereby improved stability is achieved in ~he resulting room temper-ature vulcanizable organopolysiloxane composition.
In an additional aspect of ~he ~resent case, there is provided a method of making a stable, one-pAckage room ~mperatuxe vulcanizable polyalkoxy-terminated organo-polysiloxane composition which comprises agitating, under su~s~antially anhydrou~ conditions, a room temperature vulcani2able material selected from (i) a mixture comprising on a weigh~ Dasis (a) 100 parts o a silanol-terminated polydiorgano-~iloxane consisting essentially of chemically combined units of Fonmula (3);
~b) an amount of silane of ~ormula ~4~ sufficient to scavenge available -OH in the RTV compositibn ~ 24 ~
and ~rovide up to ?.% by weight excess, based o~ the weight of RTV composition;
(c3 0 to 10 parts of t.he cross-linking silane of Formula t5~; -~d) an efective amoun~ of a condensation c~talyst, and ~e) O to 5 part~ of curing accelerator selected from substituted guanidines, amines and mixtures thereof wherein, the condensation ca~alyst i5 added after the silanol-termina~ed polydiorganosiloxane and scavenging silane are mixed; and (ii) a mixture comprisin~;
(a) 1~0 parts of the polyalkoxy-terminated orgallopolysiloxane of Formula (7);
(b) O to 10 parts of the cross-link1ng silane of Formula (5);
(c) an effective amount of a condensation catalys~;
(d) a stabilizin~ amount of silane scavenger xn of Formula (1)~ and (e) O t.o 5 parts of curing accelerator xelected from subs~ituted guanidines, amines, and mixtures thereof.
- c -- 25 ~
R~dicals included wi~hin R of Formulas (2), (3)~ and ; (7) are, for example, aryl radicals and halogenated a~yl radicals, such ~ phenyL, tolyl, chlorophenyl~ naphthyl;
alipha~ic and cycloallphatic radicals, for example, cyclo-hPxyl, cyclobutyl; al~yl and alkenyl radicals, such as methyl, ethyl, propyl, chloropropyl, vinyl, allyl, trifluoropropyl; and cyanoalkyl radicals, for example, cyanoethyl, cyanopropyl, cyanobutylO ~adicals preferably ith ~1 are, for example, C(1-8) f~r example, methyl, ethyl, propyl, butyl, pentyl;
C(7_13~ aralkyl radicals~ for example, benzyl; phenethyl;
alk~lether r~dicals such as 2-me~hoxy~thyl; alkylester radicals t for example 2-acetoxyethyl; alkylketone radicals, for example l-butan-3-onyl; alkyl~yano radi.cals, for example 2~cyanoe~hyl. Radicals included with R2 are the same ox d.ifferent radi.cals included within R radicals.
In Formula (1-7), where R, Rl, and ~2, can be more than 1 radical, the~e radicals can be the same or different.
Some o the scavengers for chemically combined hydroxy ~0 xadicals included within one or more of ~ormula (4), (6), and (1~, are fo~ example;
Oximatosilanes such as, methyldimRthoxy(ethylmethylketoximo~silane;
methylmethoxybis-(ethylmethyl~etoximo)silane;
methyldimethoxy(acetaldoximo)silaneO
Carbamatosilanes such as, methyldimethoxy(N-methylcarbama~o3silane;
ethyldimethoxy(N-methylcarb2mato)silane.
¦ 60SI 640 Enoxysilanes such as, methyldimethoxyis~propenoxysilane;
trimethoxyiSP~F enoxysilane;
methyltri-iso~pro~enoxy~ilane;
methyldimethoxy(bu~-2-ene~2-oxY)silane;
methyldimethoxy(lS phenylethenoxy)silane;
methyldimethoxy-2(1-carboe~hoxypropenoxy~silane.
Aminosilanes such as, methyl~ethoxydi-NrMethylaminosilane;
vinyldimethoxymethylaminosilane;
tetra~N~N-diethylaminosilan2 methyldimethoxy-methylaminosilane;
methyltricyclollexylaminosilane;
methyldimethoxyethylamlnosilane;
dimethyldi-N,N-dimetllylaminosilane;
methyldimethoxyisopropylaminosilane dimethyldi N,~ dietlylaminosilane.
Amidosilanes such as, ethyldimethoxy(n-ethylpropionamido)silane;
meth~"ldimethoxy(N-methylacetamido)s.ilane;
methyltri(N~methylace~.amido)silane;
methyltL~i(N-methylbenzamido~silane;
ethyldimPthcxy(N-methylacetamido)silane;
methyltri(N-methylbenzamido)silane, methylmethoxybis(N-me hylacetamido)silane;
methyldimethoxy~caprolactamo~silane, trimethoxy(N-methYlacetamido)silane.
~5~33 ( `~-- 27 - 60S:~ 640 Imida tosi lane such as, methyldimethoxyethylace~imidatosilane;
methyldimethc3x~/propylac:eti~ida~osi lane .
t~reidosi lanes such as, methyldime~chvxy (N,N' ,N'~trimethylureido~ silane;
methyldimethoxy t~-allyl-N ' ,~ ' -dimethylureido~
ilane;
methyldimethoxy(N-phenyl ~',N'-dimethylureido-silane.
Isocyanatosilanes such as, methyldimethoxyisocyanatosilane;
dimethyoxydiisocyanatosilane.
Thioisocyanatosi lanes such as, methyldimethoxythioisoc~arlatosilane, methylm~thoxydithioisocyanatosilane.
In addition, Formula (6) scavenin~ silanes include silanes such as me~hyltxis (N-methylace~amido~ silane;
tetra ~isopro~enoxy) silane. 7~lso included are silanes havinc~
d.ifferent leaving grou?s such as dieth~la~Tino~N-meth~"lcarba~
mato) isopropenoxytM-allyl-~.l',N'-dimethylureido)silane.
Some of the cross~linking ?olyalkoxysilanes included within Formula t5) are, for example, me~hyltrirnethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, tetraethoxy-silane, vinyltrimethoxysilane, etc~
~mon~ the curing accelerators which can be used in the practice of the invention are silyl substituted ~uanidines having the formula, ~Z)~Si ~R ) ~_g (8) where Rl is as previously defined, Z is a ~uanidine radical of the formula, ( )2 ~=N P3 R is divale~t C~2 ~) alkylene radical, ~ and R axe selected from hvdro~en and C(l ~) alkyl radicals and g is an integer equal ~o 1 to 3 inclusive. IJI addition, alkyl substi uted guanidines havin~ the formula, 2 ~C=N R6 (10) ~ P~ ) 2N~
where R and R5 are as previously defined and R i~ a C(l 8) alk~l radical, also can be e~?loved. Some of ~he silyl substituted guanidines included within Formula (8) are shown by Takago, U.S~ Pa~ents 4,180,~42 and 4,248,993 In addition to the above substituted ~uanidines, there can be used various amir~es, fc~r example, di-n-hexyl~
amine, dichclohexyla~nine, di~n-octylamine, hexa~ethox~methyl melamine, and silylated a~ines, for e~am~le, y~aminopropyl~
trimethoxysilane and methyldirnethoxydi-n--hexyla~inosilane.
Methyldimethoxy~di-n-hexylarninosilane acts as both a scaven~er and curing acceleratorO The primary amines, secorldary amines, silylated secondary amines are preferred, and s~condary amir~es, and silyla~ed secondary amines are ~articularly preferred.
Silylated secondary amines such as alkyldialkoxy~n-dialkyl a~inosilanes and s~uanidines such alkyldialkoxyalkylguanidyl~
silanes which are useful as cure accelerators herein also act as scavencers and, in certain instances, as stabilizers in the com?ositions of this invention.
~ 5~33 Effective amounts of the condensation catalysts which can be used in the practice of ~he ?resent invention to facilitate the cure of ~he RTV compositions are~ for exam~le, 0.001. to 1 part based on the weight of 100 parts cf th~
silanol-terminated ~olydiorganosiloxane of Formula (1).
There are included tin compounds, for example, dibu~yltin-dilauraeate; dibutyltindiac~tate, dibutyltindime~hoxide, carbomethoxyphenyl ~in tris-~erate; tin octoate; isobutyl tin triceroate; dime~hyl din dibutyra~e; dime~hyl tin di~
neodeconoate; ~riethyl tin tartrate; dibutyl tin diben~oate;
tin oleate; tin naphthenate; butyltintri~2-ethylhexoate;
tinbutyrate. The preferred condensation catalysts are tin com~ounds and dibutyltindiacetate is particularly preferred.
Titanium com~ounds which can be used are, for exarn~le, 1,3-propanedioxytitanium bis(ethylaceto~cetate):
1,3-pro~anedioxvtitanium bis~acetylacetonate); diisopro poxytitani~m bis(acetylacetonate); titanium naphthenate;
tetrabutyltita~a~e, te~ra 2--ethylhexvltitanate; tetra-~henvltitanate; tetraoctadecyltitanate, ethyltriethano~
lamin~titanate. Xn addition be~a-dicarbonyltitanium com-pounds as shown by Weyenberg, U.S. Patent ~,334,067 can be used as condensation catalysts in the ~resent invention.
Zirconium compounds, for example, zirconium octoate, also can be usedc Further examples of metal condensation catalysts are, for example, lead 2-ethylocto~te; iron 2-ethylhexoate;
3~
30 - 60SI~640 cobalt 2-ethylhexoa-te; manganese 2-ethylhexoate;
zinc 2-ethylhexoate; antimony octoate; bismuth naphthenate; zinc naphthenate; zinc stearate~
Examples of non-metal condensation catalysts are hexylammonium acetate and benzyl-trimethylammonium acetate.
The preferred catalys-t for the presen-t compositions is dibutyltindiacetate. However, other tin soaps may be utilized with almost equal effectiveness.
As used hereinafter, the expressions "molsture-free conditions" and "substan-tially anhydrous conditions," with reference to making the RTV compositions of the present invention, mean mixing in a dry box, or in a closed container which has ~een subjected to vacuum to remove air, which thereafter is replaced with a dry inert yas, such as nltrogen. Experience has shown that a sufficient amount of silane of Formula (l) should be utilized as previously defined. Temperatures can vary from 0 C. to about l~0 C. depending upon the degree of blending, the type and amoun-t of filler, a mixture of the silanol terminated polydiorganosiloxane, filler and an effective amount of the scavenging silane o:E
Formula (4) sufficient to effect the substantia:L
elimination of hydroxy functional radicals and to end-cap the pol.ymer. This "end-capping" and scavenCJing procedure can require several minutes, hours, or even days, clependirlg upon such factors as the nature o:E the X
.l.eavincJ cJroup, the number of -OR1 radicals on the scavenging silane, etcO There then can be added to the substantially silanol-free mixture, the condensation catalyst, the cross-lin}cing silane, or mixture thereof, along with other ingredients, for example, the curing accelerator and pigments.
A preferred procedure for making the RTV
composition of the present invention is to agitate under substantially anhydrous conditions, a mixture oE the silanol terminated polydiorganosiloxane, filler and an effective amoun~ of the scavenying silane of Formula (4) sufficient to effect the substantial eli.mination of hydroxy functional radicals and to end-cap the polymer. This "end capping" and scavenging procedure can require several minutes, hours, or even days, depending upon such factors as the nature of the X leaving group, the number of -ORl radicals on the scavenging silane, etc There then can be added to the substantially silanol-free mixture, the condensa-tion catalyst, the cross-lin]cing silane, or mixture the:reof, along with other ingredien-ts, for example, the curing accelerator and pigments.
A stabili%ing excess of the scavenging silane can be used in the initial or final stages of the mixing procedure if desired in amounts previously defined.
In instances where the polyalkoxy-~e:rm.i.nated organopolysiloxane o:E Formula (7) is madeby a procedure not requ:iring the use of scavenging silane of Formula (~), stabilizing amounts of scavenging silane can be added before, with, or af-ter the addition of condensation catalyst. Alternative ' procedures for making ~olyalkoxy-terminated org~nopoly-siloxane are shown as previously indicated hy Cooper e~ al.
U.S. Patent ~,542,901.
The preferred method of makin~ the RTV compositions cf the present case, tha~ ~s a low modulus non-corrosive, fast-curing composition that is shelf-stable, is to utili~e a polyalkoxy-terminated diorganopolysiloxane polymer, that is to form the polyalkoxydioryanopolysilo~ane first, remove or scavenge the hydroxy groups in the composition, and then add the other in~redien~s as desired. This may be done by adding the silanol polymer of Formula (1) tv the cross-linking agent of Formula (5), that is prereacting the silanol polymer with a cross-linkiny a~ent, and in the presence preferably of a catalyst and preferably a~ amine catalyst such as hexylamine to ~roduce the desired dialkoxy end-ca2ped polymer nd then taking this di~ or trialkoxy end-capped polymer and adding a scavenger to it so as ~o absorb the silanol grou~s.
Then the other ingxedients can be added to the co~position under substantially anhydrous conditions to prepare a one-compon~nt ~TV package, which will be shelf stable and willcure at a sufficiently fas~ rate, that is bc fast~curiny even with tin soap catalyst in the composition~ The first basic ingredient in accordance with the instant invention which should be added to the above ~TV system after it has been ~repared, that is, the polya~oxy material, the scavenger and the condensation catalyst is from 2 to ~0 parts 3~;3 by weight per 100 parts by weight of diorgano-polysiloxane base polymer, (that is either in terms of 100 parts by weight of the silanol polvmer of Formula (2~ or in terms of 100 parts by weight of the polyalkoxy-terminated organopolysiloxane polymer of Formula (7)) is a first plasticizer Eluid polysiloxane containing a high degree of tri-functionality or a mixture of tri- and tetra-Eunctionality and comprising (i) from 5 to 60 mole percent oE mono-alkylsiloxy, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of tri~
alkylsiloxy units and (iii) from 34 to 9~ mole percen-t of dialkyl siloxy units, said first plasticizer poly-siloxane containing from 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
It should be pointed ou-t that this first plasticizer polysiloxane Eluid may be added generally at a concentration of 2 to 20 parts by weight oE
the base polymer generally, or more preEerably a concentration of 5 to 15 parts by weight per 100 parts by weigh-t of a base polymer. Such a poly-siloxane Eunctions in the instant compositionas a plasticizer and adhesion promoter and more particularly, a plasticizer. Too much of it cannot be added to plas-ticize the compositions, since by itself as a result of its tri-functionality, it will cross-link and unduly increase the viscosity of the system. Above 20 parts by weight per 100 ÇOSi-640 - 34 ~
parts of the ~ase Dolymer is undesirableO ~ccordingly, ~enerally, it should no~ be used above 20 parts by weight and below 2 parts by w~ight it does not have much of an ef f ect O
The highly trifunctional polysiloxane component can be made by means known ~o those skilled in this art. For example, a mixture O r monoalkyltrichlorosilane;
( ii ) dialkyldichlorosi lane, and ~iii) alkyltrichlorosilane, si.licone tetrachloride or a mix~ure thereof, at the appropriate mole ratio can be run into toluesle and water to co-hydrolyze them.
Then the mixture can be hPated, e.g., at abou~ 60C.
for a time, e~g., 3 hours sufficient ~o insure completion of the reaction. The oil phase is separated an~ neutrdlized, e.~., by washing with an aqueous solution of sodium carbonate or bicarbonate. ~fter filtration to remove insolubles and devolatili~.ation~ e~., by heating at about 140C. under a vacuum, e.g., about 2 mm or mercury, the fluid polysiloxane~
2n c~mponent remains as the residue. Preferred for economy's sake i~ to keep the silicon bonded hydroxyl content to less than 0~6% by weight to minimize the viscosity of the final composition and to ~eep the cross-lin~er level to a minimum.
This is done by heating ~he product at ll~C. in the presence 2S of a~pro~imately 1~ of sodiu~ carbo~ate. The water from the silanol condensation can oonverli ently be removed by azeotro~ic ~34-~- c 3~
~istillatio~, eOg.r with tolueneO ~ftex removal of the toluene ~y distillation~ ~he product is filtered before use~
Beers, U.S. Patent No. 3t382~2Q5 d~ted Ma~7 7~ 1968 iS
incorporat~d for its illustrative teachings.
Preferably, the 1uid will have a viscosity in the range of 15 to 3ao cps~ at 25C. Preferably, also, in the fluid polysiloxan plasticizer at least 50 per~ent of the alkyl substituents are methyl and the fluid comprises from 0.2 to 0.6 percent by weigh~ o silanol. Especially, preferably, the monoalkylsiloxy units, siloxy units or mixed such uni~s comprise about 10 to 30 mole percent, the trialkylsiloxy units comprise rom 3 to 5 mole percent, the dialkyl~iloxy uni~s comprise from 65 to 87 molP percent, and the silanol content is about 0.2 to 0.6 percent by weightO
~ccordingly, while such trifunctional fluid will plasticize the base composition so as to make it low modulus, it will not in all.cases make i~ sufficiently.lcw modulus ~Id suficient-ly 1~ in viscosity by itself. According:ly, it is hiqhly desirabl~ there be 100 parts of ~he ba~e polyrr~ utilized in ~ddi.tion to the trifunc-tional 1uid, from 1.0 to SO parts by weight: of a second plasticizer per 100 parts of said base organopolysi loxane polymer .
~s stated previously, by base organopolysiloxane polymer, it is meant either the si lanol terminated diorgano-polysiloxane polymer of Formula (23 or the polyalkox.y-terminat~d diorganopolysiloxane polymer of Formula ~7J or
comoosition as ~reviously defined for the scavenging silane of Formula ~41. In additio~, there can be used w' th scavengers of Formulas (4) or (6~ at least 0.01 ?art and up to 10 parts of the cross lin~in~ silane of Formula ~5~.
~5~33 ~ 18 - 60SI-640 The polyalkoxy-terminated organopolysiloxane of the present invention has the formula (R )b ~ R ~ sl(OR )3 (b-~e) (7) Xe R Xe where R, R , R , X, n and b are as previously defined and e i.s equal to 0 to 1 and the sum of b + e is equal to 0 to 1. The polyalkoxy-terminated organopolysiloxane of Formula (7), can be made by various procedures. One procedure is taught by Cooper et al, U.S. Patent 3,542,901, issued November ~4, lg70, involving the use of a polyalkoxysilane with a silanol-terminated polydiorganosiloxane in the presence of an amine catalyst as discussed above.
A method no-t taught by Cooper et al is the use o:E the silane scavenger of Formula (4) as an end-capper with silanol-terminated polydiorgano-siloxane used i.n the practice of the invention.
The additives of the present case are pre.ferably used where the polyalkoxy diorganopolysiloxane of Formula (7~ is first formed and then the additives are added.
In Formulas (1-7) J R is preferably selected from C(l 13) monovalent hydrocarbon radicals, halogerlated hydrocarbon radicals and cyano alkyl radicals, Rl is preferably a C(l 8) alkyl radical or a C(7-13) aralkyl radical, R2 i5 preferably methyl, phenylg or vinyl.
The preferxed X radicals in Formulas ~3), ~5)0 and t61 are amido, amino and enoxy, and ~h most pre-ferred is amidoO
It has been further found that improved cure rates can be achieved if minor amoun~s of amines, sub-stituted guanidines, or mixtures thereof, are utilized as curing accelera~ors in the polyalkoxy compositions of the present invention. Ihese curing accelera~ors also serve to catalyse the ability of the enoxy leaving group to act a~ a scavenger. There can be used from O~l to 5 parts, and preferably from abou~ .3 to l part of curing accelerator, per lO0 parts of the silanol-terminated polymer of Formula (2), or which consists of chemically combined units of Formula ( 3 ), or lO0 parts of the polyalkoxy-terminated polymer of ~ormula (7) to substantially reduce the tack~free time ~TFT) of the RTV composition of the present invention. This enhanced cure rate i5 maintained after it has been ~0 a~ed ~or an extended shelf period, for example 6 months or more at an~ient temperatures, or a comparable period uncler acceleratecl aging condi~ions~ Its cure proper-ties after the extended shelf period will be sub stantially similar to its initial cure propertiesg for example, tac~fre~ ~ime ~TFT), shown by the RTV composl-tion upon bein~ freshly mlx d and im~ediately exposed to atmospheric moisture.
It appears -that the curing accelerators described herein, in addition to decreasin~ the tack-free times of the RTV compositions of this invention, also provide a surl?rising stabilizing e:Efect for paxticular P~TV compo-SitionS ::atalyzed wi~ch cer~ain corldensatioll ca~alysts which exhi~i~ a marked len~theniny of tack-free time after 1~ accelerated aging. For this class of condensation cata-lysts, addition of amines, substi~u~ed g~anidines and mixtures thereof described herein provide stable RTV
compositions which exhibit ~ fast cur~ rate initially, i.e., less than about 30 minutes which remains sub-stantially unchan~ed after accelerated aging.
The RTV compositions of the present invention can cuxe to a depth of abol~t 1~8" thickness within 24 hours. Durometer Hardness (5hore ~) can then be deter-mined and used ~o evaluate the cure of the compositions 2~ as shown in the examples.
;~ 3~
A general way of stat ng the polymer system of White e~ al~ is tha~ there is present a one-package subs~antially anhydrous room ~emperature vulcanizable organopolysiloxane composi~ion stable under ambient conditions in the substantial ab-sence of moisture over an extended pexiod of time ~nd convertible to a substantially acid~free, tack-free elastomer comprising~ an organopolysiloxane where~
in the .silicon atom at each polymer chain end is ter-minated with at least two alkoxy radicals, (2~ an ef-fective amount of condensation catalyst; and (33 a stabilizing amount of scavenging silane of the formula, (Rl) ~, (C ~) S;X~
~here R , R2, X and c are as previously deined, f is lS all integer equal to 1 to 4 inclusive, and the sum of c + ~ is ~ual to 1 to 4 i.nclusj.ve. In addition, an effective amount of a curin~ accelerator selec~ed from substituted guanidines, amines and mixtures thereof is used.
In a fu~ther asp~ct of the present invention/ there is provided a s~able room ~emp~rature vulcani~able poly~
.~ 3~
alkcxy-terrnina~ed organopolysiloxane composition curable under ambient condi ions ~o a ~ack-free, subs~antially acid-free el as komer compri sing:
(A) 100 parts o a polyalkoxy-terminate~ organor poiysiloxane of Formula ( 7 );
(B~ O to 10 parts of a cross linking silane of Formula ( 5 );
(C) an efective amount of condensatlon catal~st; and ~D~ a ~ta~ilizin~ amount of scavenging silane of Formul~
Also included within the scope of the presen~ case is a method of making a room temperatuxe vulcanizable organo-polysiloxane composition under subs~antially anhydrous con~
ditions utilizin~ an effective amount of a condensation lS catalyst with a silanol-terminated organopolysiloxane and a polyalkGxysilane cross linking ayent, the improvement which comprises: (1) adding to the silano.l-terminated organopolysiloxane a sta~ilizing amount of a polyalkoxy-silane which i5 both a scavenger for hydroxy functional groups and a cxoss linking a~ent of the formula, (~2)b ~ )4-~b+a) Sl(X)a where Rl, R2, X~ a and b are as previously defined, and thereater adding an efective amount of a condensatio-catalyst, whereby improved sta~ y is ach-eved in the ~S resul~ing room tempera~ure ~Julcani~able organopolysiloxane compositions.
Another method of the present case is making a room temperature vulcanizable organopolysiloxane composition under subs~.antially anhydrous conditions u~ilizing an ef-fective amount of a condensation ca~alyst wit~ an organo~
polysiloxane wherein the silicon atom at each polymer chain cnd is terminated with at leas~ two alkoxy radicals/ which involv~s the improvement which comprises addiny to said polyalkoxy-terminated organopolysiloxane (1) a ~tabilizing amQunt of a silane scavenger for hydroxy functional groups of the formula, ( 12) C
(~lo~4-(c+~Si(X)f where R , R , X, c and f are as previously defined and (2) an effective amount of a condensation catalyst, whereby improved stability is achieved in ~he resulting room temper-ature vulcanizable organopolysiloxane composition.
In an additional aspect of ~he ~resent case, there is provided a method of making a stable, one-pAckage room ~mperatuxe vulcanizable polyalkoxy-terminated organo-polysiloxane composition which comprises agitating, under su~s~antially anhydrou~ conditions, a room temperature vulcani2able material selected from (i) a mixture comprising on a weigh~ Dasis (a) 100 parts o a silanol-terminated polydiorgano-~iloxane consisting essentially of chemically combined units of Fonmula (3);
~b) an amount of silane of ~ormula ~4~ sufficient to scavenge available -OH in the RTV compositibn ~ 24 ~
and ~rovide up to ?.% by weight excess, based o~ the weight of RTV composition;
(c3 0 to 10 parts of t.he cross-linking silane of Formula t5~; -~d) an efective amoun~ of a condensation c~talyst, and ~e) O to 5 part~ of curing accelerator selected from substituted guanidines, amines and mixtures thereof wherein, the condensation ca~alyst i5 added after the silanol-termina~ed polydiorganosiloxane and scavenging silane are mixed; and (ii) a mixture comprisin~;
(a) 1~0 parts of the polyalkoxy-terminated orgallopolysiloxane of Formula (7);
(b) O to 10 parts of the cross-link1ng silane of Formula (5);
(c) an effective amount of a condensation catalys~;
(d) a stabilizin~ amount of silane scavenger xn of Formula (1)~ and (e) O t.o 5 parts of curing accelerator xelected from subs~ituted guanidines, amines, and mixtures thereof.
- c -- 25 ~
R~dicals included wi~hin R of Formulas (2), (3)~ and ; (7) are, for example, aryl radicals and halogenated a~yl radicals, such ~ phenyL, tolyl, chlorophenyl~ naphthyl;
alipha~ic and cycloallphatic radicals, for example, cyclo-hPxyl, cyclobutyl; al~yl and alkenyl radicals, such as methyl, ethyl, propyl, chloropropyl, vinyl, allyl, trifluoropropyl; and cyanoalkyl radicals, for example, cyanoethyl, cyanopropyl, cyanobutylO ~adicals preferably ith ~1 are, for example, C(1-8) f~r example, methyl, ethyl, propyl, butyl, pentyl;
C(7_13~ aralkyl radicals~ for example, benzyl; phenethyl;
alk~lether r~dicals such as 2-me~hoxy~thyl; alkylester radicals t for example 2-acetoxyethyl; alkylketone radicals, for example l-butan-3-onyl; alkyl~yano radi.cals, for example 2~cyanoe~hyl. Radicals included with R2 are the same ox d.ifferent radi.cals included within R radicals.
In Formula (1-7), where R, Rl, and ~2, can be more than 1 radical, the~e radicals can be the same or different.
Some o the scavengers for chemically combined hydroxy ~0 xadicals included within one or more of ~ormula (4), (6), and (1~, are fo~ example;
Oximatosilanes such as, methyldimRthoxy(ethylmethylketoximo~silane;
methylmethoxybis-(ethylmethyl~etoximo)silane;
methyldimethoxy(acetaldoximo)silaneO
Carbamatosilanes such as, methyldimethoxy(N-methylcarbama~o3silane;
ethyldimethoxy(N-methylcarb2mato)silane.
¦ 60SI 640 Enoxysilanes such as, methyldimethoxyis~propenoxysilane;
trimethoxyiSP~F enoxysilane;
methyltri-iso~pro~enoxy~ilane;
methyldimethoxy(bu~-2-ene~2-oxY)silane;
methyldimethoxy(lS phenylethenoxy)silane;
methyldimethoxy-2(1-carboe~hoxypropenoxy~silane.
Aminosilanes such as, methyl~ethoxydi-NrMethylaminosilane;
vinyldimethoxymethylaminosilane;
tetra~N~N-diethylaminosilan2 methyldimethoxy-methylaminosilane;
methyltricyclollexylaminosilane;
methyldimethoxyethylamlnosilane;
dimethyldi-N,N-dimetllylaminosilane;
methyldimethoxyisopropylaminosilane dimethyldi N,~ dietlylaminosilane.
Amidosilanes such as, ethyldimethoxy(n-ethylpropionamido)silane;
meth~"ldimethoxy(N-methylacetamido)s.ilane;
methyltri(N~methylace~.amido)silane;
methyltL~i(N-methylbenzamido~silane;
ethyldimPthcxy(N-methylacetamido)silane;
methyltri(N-methylbenzamido)silane, methylmethoxybis(N-me hylacetamido)silane;
methyldimethoxy~caprolactamo~silane, trimethoxy(N-methYlacetamido)silane.
~5~33 ( `~-- 27 - 60S:~ 640 Imida tosi lane such as, methyldimethoxyethylace~imidatosilane;
methyldimethc3x~/propylac:eti~ida~osi lane .
t~reidosi lanes such as, methyldime~chvxy (N,N' ,N'~trimethylureido~ silane;
methyldimethoxy t~-allyl-N ' ,~ ' -dimethylureido~
ilane;
methyldimethoxy(N-phenyl ~',N'-dimethylureido-silane.
Isocyanatosilanes such as, methyldimethoxyisocyanatosilane;
dimethyoxydiisocyanatosilane.
Thioisocyanatosi lanes such as, methyldimethoxythioisoc~arlatosilane, methylm~thoxydithioisocyanatosilane.
In addition, Formula (6) scavenin~ silanes include silanes such as me~hyltxis (N-methylace~amido~ silane;
tetra ~isopro~enoxy) silane. 7~lso included are silanes havinc~
d.ifferent leaving grou?s such as dieth~la~Tino~N-meth~"lcarba~
mato) isopropenoxytM-allyl-~.l',N'-dimethylureido)silane.
Some of the cross~linking ?olyalkoxysilanes included within Formula t5) are, for example, me~hyltrirnethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, tetraethoxy-silane, vinyltrimethoxysilane, etc~
~mon~ the curing accelerators which can be used in the practice of the invention are silyl substituted ~uanidines having the formula, ~Z)~Si ~R ) ~_g (8) where Rl is as previously defined, Z is a ~uanidine radical of the formula, ( )2 ~=N P3 R is divale~t C~2 ~) alkylene radical, ~ and R axe selected from hvdro~en and C(l ~) alkyl radicals and g is an integer equal ~o 1 to 3 inclusive. IJI addition, alkyl substi uted guanidines havin~ the formula, 2 ~C=N R6 (10) ~ P~ ) 2N~
where R and R5 are as previously defined and R i~ a C(l 8) alk~l radical, also can be e~?loved. Some of ~he silyl substituted guanidines included within Formula (8) are shown by Takago, U.S~ Pa~ents 4,180,~42 and 4,248,993 In addition to the above substituted ~uanidines, there can be used various amir~es, fc~r example, di-n-hexyl~
amine, dichclohexyla~nine, di~n-octylamine, hexa~ethox~methyl melamine, and silylated a~ines, for e~am~le, y~aminopropyl~
trimethoxysilane and methyldirnethoxydi-n--hexyla~inosilane.
Methyldimethoxy~di-n-hexylarninosilane acts as both a scaven~er and curing acceleratorO The primary amines, secorldary amines, silylated secondary amines are preferred, and s~condary amir~es, and silyla~ed secondary amines are ~articularly preferred.
Silylated secondary amines such as alkyldialkoxy~n-dialkyl a~inosilanes and s~uanidines such alkyldialkoxyalkylguanidyl~
silanes which are useful as cure accelerators herein also act as scavencers and, in certain instances, as stabilizers in the com?ositions of this invention.
~ 5~33 Effective amounts of the condensation catalysts which can be used in the practice of ~he ?resent invention to facilitate the cure of ~he RTV compositions are~ for exam~le, 0.001. to 1 part based on the weight of 100 parts cf th~
silanol-terminated ~olydiorganosiloxane of Formula (1).
There are included tin compounds, for example, dibu~yltin-dilauraeate; dibutyltindiac~tate, dibutyltindime~hoxide, carbomethoxyphenyl ~in tris-~erate; tin octoate; isobutyl tin triceroate; dime~hyl din dibutyra~e; dime~hyl tin di~
neodeconoate; ~riethyl tin tartrate; dibutyl tin diben~oate;
tin oleate; tin naphthenate; butyltintri~2-ethylhexoate;
tinbutyrate. The preferred condensation catalysts are tin com~ounds and dibutyltindiacetate is particularly preferred.
Titanium com~ounds which can be used are, for exarn~le, 1,3-propanedioxytitanium bis(ethylaceto~cetate):
1,3-pro~anedioxvtitanium bis~acetylacetonate); diisopro poxytitani~m bis(acetylacetonate); titanium naphthenate;
tetrabutyltita~a~e, te~ra 2--ethylhexvltitanate; tetra-~henvltitanate; tetraoctadecyltitanate, ethyltriethano~
lamin~titanate. Xn addition be~a-dicarbonyltitanium com-pounds as shown by Weyenberg, U.S. Patent ~,334,067 can be used as condensation catalysts in the ~resent invention.
Zirconium compounds, for example, zirconium octoate, also can be usedc Further examples of metal condensation catalysts are, for example, lead 2-ethylocto~te; iron 2-ethylhexoate;
3~
30 - 60SI~640 cobalt 2-ethylhexoa-te; manganese 2-ethylhexoate;
zinc 2-ethylhexoate; antimony octoate; bismuth naphthenate; zinc naphthenate; zinc stearate~
Examples of non-metal condensation catalysts are hexylammonium acetate and benzyl-trimethylammonium acetate.
The preferred catalys-t for the presen-t compositions is dibutyltindiacetate. However, other tin soaps may be utilized with almost equal effectiveness.
As used hereinafter, the expressions "molsture-free conditions" and "substan-tially anhydrous conditions," with reference to making the RTV compositions of the present invention, mean mixing in a dry box, or in a closed container which has ~een subjected to vacuum to remove air, which thereafter is replaced with a dry inert yas, such as nltrogen. Experience has shown that a sufficient amount of silane of Formula (l) should be utilized as previously defined. Temperatures can vary from 0 C. to about l~0 C. depending upon the degree of blending, the type and amoun-t of filler, a mixture of the silanol terminated polydiorganosiloxane, filler and an effective amount of the scavenging silane o:E
Formula (4) sufficient to effect the substantia:L
elimination of hydroxy functional radicals and to end-cap the pol.ymer. This "end-capping" and scavenCJing procedure can require several minutes, hours, or even days, clependirlg upon such factors as the nature o:E the X
.l.eavincJ cJroup, the number of -OR1 radicals on the scavenging silane, etcO There then can be added to the substantially silanol-free mixture, the condensation catalyst, the cross-lin}cing silane, or mixture thereof, along with other ingredients, for example, the curing accelerator and pigments.
A preferred procedure for making the RTV
composition of the present invention is to agitate under substantially anhydrous conditions, a mixture oE the silanol terminated polydiorganosiloxane, filler and an effective amoun~ of the scavenying silane of Formula (4) sufficient to effect the substantial eli.mination of hydroxy functional radicals and to end-cap the polymer. This "end capping" and scavenging procedure can require several minutes, hours, or even days, depending upon such factors as the nature of the X leaving group, the number of -ORl radicals on the scavenging silane, etc There then can be added to the substantially silanol-free mixture, the condensa-tion catalyst, the cross-lin]cing silane, or mixture the:reof, along with other ingredien-ts, for example, the curing accelerator and pigments.
A stabili%ing excess of the scavenging silane can be used in the initial or final stages of the mixing procedure if desired in amounts previously defined.
In instances where the polyalkoxy-~e:rm.i.nated organopolysiloxane o:E Formula (7) is madeby a procedure not requ:iring the use of scavenging silane of Formula (~), stabilizing amounts of scavenging silane can be added before, with, or af-ter the addition of condensation catalyst. Alternative ' procedures for making ~olyalkoxy-terminated org~nopoly-siloxane are shown as previously indicated hy Cooper e~ al.
U.S. Patent ~,542,901.
The preferred method of makin~ the RTV compositions cf the present case, tha~ ~s a low modulus non-corrosive, fast-curing composition that is shelf-stable, is to utili~e a polyalkoxy-terminated diorganopolysiloxane polymer, that is to form the polyalkoxydioryanopolysilo~ane first, remove or scavenge the hydroxy groups in the composition, and then add the other in~redien~s as desired. This may be done by adding the silanol polymer of Formula (1) tv the cross-linking agent of Formula (5), that is prereacting the silanol polymer with a cross-linkiny a~ent, and in the presence preferably of a catalyst and preferably a~ amine catalyst such as hexylamine to ~roduce the desired dialkoxy end-ca2ped polymer nd then taking this di~ or trialkoxy end-capped polymer and adding a scavenger to it so as ~o absorb the silanol grou~s.
Then the other ingxedients can be added to the co~position under substantially anhydrous conditions to prepare a one-compon~nt ~TV package, which will be shelf stable and willcure at a sufficiently fas~ rate, that is bc fast~curiny even with tin soap catalyst in the composition~ The first basic ingredient in accordance with the instant invention which should be added to the above ~TV system after it has been ~repared, that is, the polya~oxy material, the scavenger and the condensation catalyst is from 2 to ~0 parts 3~;3 by weight per 100 parts by weight of diorgano-polysiloxane base polymer, (that is either in terms of 100 parts by weight of the silanol polvmer of Formula (2~ or in terms of 100 parts by weight of the polyalkoxy-terminated organopolysiloxane polymer of Formula (7)) is a first plasticizer Eluid polysiloxane containing a high degree of tri-functionality or a mixture of tri- and tetra-Eunctionality and comprising (i) from 5 to 60 mole percent oE mono-alkylsiloxy, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of tri~
alkylsiloxy units and (iii) from 34 to 9~ mole percen-t of dialkyl siloxy units, said first plasticizer poly-siloxane containing from 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
It should be pointed ou-t that this first plasticizer polysiloxane Eluid may be added generally at a concentration of 2 to 20 parts by weight oE
the base polymer generally, or more preEerably a concentration of 5 to 15 parts by weight per 100 parts by weigh-t of a base polymer. Such a poly-siloxane Eunctions in the instant compositionas a plasticizer and adhesion promoter and more particularly, a plasticizer. Too much of it cannot be added to plas-ticize the compositions, since by itself as a result of its tri-functionality, it will cross-link and unduly increase the viscosity of the system. Above 20 parts by weight per 100 ÇOSi-640 - 34 ~
parts of the ~ase Dolymer is undesirableO ~ccordingly, ~enerally, it should no~ be used above 20 parts by weight and below 2 parts by w~ight it does not have much of an ef f ect O
The highly trifunctional polysiloxane component can be made by means known ~o those skilled in this art. For example, a mixture O r monoalkyltrichlorosilane;
( ii ) dialkyldichlorosi lane, and ~iii) alkyltrichlorosilane, si.licone tetrachloride or a mix~ure thereof, at the appropriate mole ratio can be run into toluesle and water to co-hydrolyze them.
Then the mixture can be hPated, e.g., at abou~ 60C.
for a time, e~g., 3 hours sufficient ~o insure completion of the reaction. The oil phase is separated an~ neutrdlized, e.~., by washing with an aqueous solution of sodium carbonate or bicarbonate. ~fter filtration to remove insolubles and devolatili~.ation~ e~., by heating at about 140C. under a vacuum, e.g., about 2 mm or mercury, the fluid polysiloxane~
2n c~mponent remains as the residue. Preferred for economy's sake i~ to keep the silicon bonded hydroxyl content to less than 0~6% by weight to minimize the viscosity of the final composition and to ~eep the cross-lin~er level to a minimum.
This is done by heating ~he product at ll~C. in the presence 2S of a~pro~imately 1~ of sodiu~ carbo~ate. The water from the silanol condensation can oonverli ently be removed by azeotro~ic ~34-~- c 3~
~istillatio~, eOg.r with tolueneO ~ftex removal of the toluene ~y distillation~ ~he product is filtered before use~
Beers, U.S. Patent No. 3t382~2Q5 d~ted Ma~7 7~ 1968 iS
incorporat~d for its illustrative teachings.
Preferably, the 1uid will have a viscosity in the range of 15 to 3ao cps~ at 25C. Preferably, also, in the fluid polysiloxan plasticizer at least 50 per~ent of the alkyl substituents are methyl and the fluid comprises from 0.2 to 0.6 percent by weigh~ o silanol. Especially, preferably, the monoalkylsiloxy units, siloxy units or mixed such uni~s comprise about 10 to 30 mole percent, the trialkylsiloxy units comprise rom 3 to 5 mole percent, the dialkyl~iloxy uni~s comprise from 65 to 87 molP percent, and the silanol content is about 0.2 to 0.6 percent by weightO
~ccordingly, while such trifunctional fluid will plasticize the base composition so as to make it low modulus, it will not in all.cases make i~ sufficiently.lcw modulus ~Id suficient-ly 1~ in viscosity by itself. According:ly, it is hiqhly desirabl~ there be 100 parts of ~he ba~e polyrr~ utilized in ~ddi.tion to the trifunc-tional 1uid, from 1.0 to SO parts by weight: of a second plasticizer per 100 parts of said base organopolysi loxane polymer .
~s stated previously, by base organopolysiloxane polymer, it is meant either the si lanol terminated diorgano-polysiloxane polymer of Formula (23 or the polyalkox.y-terminat~d diorganopolysiloxane polymer of Formula ~7J or
5~33 various mixtures of bo~h. Since the alkoxy groups add very lit~le to the mole~ular wPight of ~he polymer, the concentration cf the varlous additives in addi~ion to the tri~
function21 fluid that will be discussed below will be sub-stantially the same as expressed in terms of either polymersystemO
~ ccordingly, per 100 parts by weight of the base orqano-~olysiloxane polymer there m~y be utilized from 5 to 60 parts by weight of a second plasticizer which is a linear triorganosiloxy end-sto~ped diorganopolvsiloxan-e polymer of a viscosi~y varying from 10 to 20, noo centi~oise at 25C.
and in which the organo grou~s are selected from C(l 8) monovalent hydrocarbon radicals, More preerably, these monovalent hydrocarbon radicals are a].kyl radicals of 1 to 8 carbon atoms. Thus, preferably, the s~cond plasticizer has ~he formula R
R - sio ~ SiO - ~ R20 (11) l20 ~ l20 t where R20 is a monovalent hydrocarbon radical~ ~referably an alkyl or phenyl radical of C(l ~ carbon ato~s or genexal~y ~o Ctl 8) alkyl or aryl radical~a~ varies such that the vis-coslty of the polymer varies from 10 ~o 20, ono centipoise at 25C. Most preferably, the R group is ~ethyl and the polymer has a viscosity varying from 10 ~o ln, ooo centipoise at 25C. more pre~erably having a viscosity varying from 10 to 1000 cPntipoise at 25~C. Generally, such polymers by ~he way they are made have from 500 to 1500 parts OH.
per mi~lion of silanol as/ The general process for producing such plasticizer of ~ormula ~11) above is to hydrolyze ~he appropriake chlorosilanes. ~hus~ triorganochlorosilane i5 hydrolyzed with diorg~nodichloxosilane in water, then th~
hydrolyzate is removed and purified by decantation and other procedures used to result in the desired linear d~-organopolysiloxane polymer of Formula (11). Such a pol~nerjust by thi5 natural hydrolysis method has usually 500 to 1500 parts per million of silznol as 0~l r and may be further purified by other procedures. However 9 this is not normally done because of the expense~ Further, such silanol groups or hydroxy groups will not cause difficulty in the presen~ situat.ion if there is a scavenge.r that absorbs substantially all such hydxoxy groups that ar~ pre~ent in such a polymer. As noted pre-vio~lsly, there has to b~ ut.ili~ed a scavenger in the instant system that absorbs all the free hydroxy groups in such a plasticizer.
As noted previously~ in order to get the Modulus of the compositiQn to a desirably low level, there has to be utiliz~d two pl~sticlzers since the trifunctional fluid . 60SI-640 ; ~ 3~ -alone will not give both the maximum decrease i~ vis cosity and modulus. Thus, if it is desired to obtain the lowest modulus, maximum adhesion and minimum vis-oosity ~o increase the ease of application of the sealant, it is necessary to use both plasticizers.
Accordingly, the most ~referred low modu1us, one-component RTV systems of the pres~nt case are pro-duced by utilizing the two plasticizers of the present invention in ~he foregoing propor~ions shown above.
~t should ~e noted that within the above bxoad ranae - of the second plasticizer of from 5 to 60 parts, there may preferably be utilized a concentration of 20 to 45 parts by wei~ht.
Another aspect of the present composition is that is low cost. The composition may be made low cost by incorporating in it anywhere from 50 to 300 parts or more by weight per 100 parts of ~he base or ganopolysiloxane of an extending filler~ An extending filler is desirably in the composition since it lowers ~0 the cost of the composition~ and adds to the s~renqth of the composition without detracting from i~s low modulus properties. Most preferably, the filler is calcium carbonate. The most desirable calcium car-bonate is the one that is ~rea~ed wi~h stearic acid.
~ 5~33 This giv~s the best flow properties ~o the uncured com-position of the present case and the best l-ow modulus properties specifi2d previouslyO Other extending fillers may be incorporated into the presen~ composition in the foregoing concentrations of calcium carbonate that have been disclosed above. Thus, other extending fillers and reinforcing fillers that may be utiliæed ~n various concen~rations, are for example, ti~anium dioxide, zirconi~m silica~e, silica aero~el, iron oxide, diatomaceous earth, fumed silica, carbon black, precipitated silica, galss fibers, polYvinyl chloride, ground quartz, ete. Th~ amoun~s of filler used can ob viously be varied within wide limits in accordance with the intende~ u~e. For example, in some sealant appllca-tions, the curable compoisitons Eor making bindingmaterial on a weight basis, as much as 700 parts or more o fillex, per lO0 parts of or9ano.Dolysiloxane can be employed. In such applications, the filler can con-sist of a major amount of extending matexials, such as yround quartz, polyvinylchloric~e, or mi~tures thereof, prefexably having arl average particle size in the range of from a~out l to lQ microns.
3~
The compositions of the present invention also can be employed as construction sealant~ znd caul~in~
compounds. The exact am~unt of fi.ller, therefore, will depend upon such factors as he application for which the organopolysiloxane composition is in~ended, the type o~ fillex utilized (that is, the density of the filler and ~s particle sizc~. Preferably~ a proportion of from 1 to 300 p2rt5 of filler, which can includ~ up to about 20 par~s of a reinorcing filler, such as fumed silioa filler, per lOa par~s of silanol-terminated organopolysiloxane is utilized.
However~ the iller~ utilized at a concentration of 50 to 300 parts by weight should be an extending iller such as calcium carbonate Por the low moduluc compositions of the present case. In addition to the extending flller, there is utili~ed from I to 50 parts and preferably fxom 1 ~ 10 parts by weight per 100 par~s o~ the base organopolysiloxane polymer of a reinforcing E.iller. The reinforclng filler may he selecte~ from precipl~ated silica~ and Pumed silica, and is most preferably fumed sillca. More preferably, 3~ -there is utilized a fumed silica ~ha~ is t.rea~ed either with cyclopolysiloxanes as disclosed in Lucas, U.SO
Patent 2,938,009 or with silazaries as disclosed in Smith, ~.S~ Paten~ 3,635,743. More pr~ferably, there is utilized from l to lO parts by weigh~ of said ~reated fumed sillca treated with cyclopolysiloxanes. Such fumed silica acts as a sa~ control agent ~o make ~he composition thixo~ropic. Thixo~xopic means that the composition when put on a vertical plane will no~. flow in the uncured sta~e, or will have only minimal flowO
Another way of making the composition thixotropic is as disclosed in Lampe~ et al., U.S. Patent 4,261,758 dated A~.ril 14, 1981. . .
Thus, per 100 parts of the base organopolysilo~ane polymer with the reinforcing fumed silica, and in addition to the ex~endina filler, ~here may be .incorporated in the RTV composition from .l ~o 2.0 parts by weight per lO0 parts by weight of the oxganopolysiloxane of a second sag con~rol agent whioh is a polye~her selec~ed from ~0 the Eormulas con~isting oE
A O (C~H2XO)~ B (12 , ~
:
and [A ~ (CxH2x)n ~ z (13) where A and B represent radlcals select.ed from the class consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cyclo alkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals and mono-nuclear aryl lower alkyl radicals wherein the alkyl gxoups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
o Il R - C - O ~ -where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethyl.olpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; y has a value of from 2 to 10; and æ has a value of from 1 to 5; n is an integer equal to from 4 to 20,000; the po:l.yether having a molecular weight of from about 300 to abou-t 200,000~
The polyether which is a sag control agent may be utili.zed in addition to the fumed silica or in place of it ~S~3~
. 60SI-640 to impart thi~otropic properties -to the uncured RTV
composition which is desired in a sealant. It must be noted that the preferred RTV composition of the present case, that is, non-corrosive, low modulus, fast-curing, shelf-stable low modulus is very desirable as a sealant in constructing buildings, in glazing applications and in ot~er manufacturing sealant applications. Accoringly, it is highly desirable that such sealant be thixotropic, that is when it is inserted in the uncured state in a creviee, it will not flow. Such thixotropy may be incorporated in the present composition by the utilization of fumed silica in small quantities in combination with the above polyethers. Further the polyethers are present at preEerably from .1 to lo0 parts by ~eight, in com-bination with the fumed silica. Although the fumeclsilica will provide sag control properties to the com-positions, these properties are considerably enhanced with the incorporation of the polyether. For more information as to the use of the polyethers as a sag control agent, one is referred to the disclosure of Lampe et al., U.S. Patent 4,261,758 dated ~pril 14, lg81 .
Examples of commercially available polyethers which may be utilized in the present invention are such polyethers as Pluracol V-7 sold by the Wyandotte Chemicals Corporation, and UNCON LB-1145 sold by the Union Carbide Corporation of Connecticut.
In place of both of these sag control or in acldition to them, there may be utilized per 100 parts by weight - 4~ ~ .
of the base organQpolysiloxane of rom . 2 ~o 2. 0 parts and more preexably from ~ 2 to 1. 5 par~s by weight of a hydrog-enal:ed castor oil.
~ n example of hydrogenated castor oil t~at may be utilized as a sag controï agent is onP known as Thixcin (tradename of NL Chemicals, Heightstown, N.J~) ~ ccordingl~, when a hydrogenated castor oil is utilized as a sas co~trol agent, ne.itherthe fumed silicz o~ ~he poly~
eth~r has to b~ utili~ed. However, when the hydrogenated ca~tor oil is no~ utilized as a sag control a~en~, ~hen ~here should be utilized the ~umed silica with the polyether.
~s an alternative thc fumed 5i lica or polyeth~r may be used alone. Please note that it must be emphasized that a reinor~ing filler is neither necessary nor desired in the present composition since it is desired to make the compositiorl low modulus~ ~ reinforcing filler in large quantities will undesirably increase the modulus of the present compos:itio~ ost ~referably, the fumed silica if ~o used is used in addition to the extending :Eil:ler such as calcium carbonate and specifically stearic acid treated cal~
cium carbonate ~hich reduces the cost of the composi~io~, keeps the viscosity o~ the uncured composition and the modulus of the uncured composition at a low level~ There may be added various other types of additives to the composition as they ~ecome available or as they are invented.
3 60Si-6~0 _ 45 -Thus, ~ may ~e incorporated into the present com~
position per 100 par~s of the organopolysiloxan2 of .1 to lO parts by weight of an adhesion ~romoter. The present compositions, that is the composition of the White et al.
Can ap~l-s N-404~949~ do not bcnd very well to substrates, Accordingly9 it is desirable to utilize a primer with such compositions or an adhesion promoter. The primers are wldesi.rable in that they add ad~itional labor costs to the applica~ion of the sealant. Accordingly, i~ is highly desirable tha there be u~ilized or incorporated into the composition a self-bonding additive. For in-stance, note the recitation of self-bondin~ additives as dis losed i.n Lucas et al.,Canadian ~r)li.cation Serial No. ~ ~ ~S 9 filed ~ ~ JI~
An additional self-bondinq additive that may be utilized in the compositions of the present case is one that may be present from .1 to lO ~arts by wei~ht of an adhesion promoter whlch has the formula R31 R33 R34 R3~
tR3~ Si ~ R32 _O ~ C ~ CHc~2 ~N ~ R ~ N ~ R ~14) where R30, R are selected from C(~_~3 monovalent hydro-carbon radicals, R32, R36 are selec~ed from C~ 23 di-vale~t hydrocarbon radicals, R38 and ~40 are selected from the class consisting of hydrogen and C(l ~ mono~
valent hydrocarbon radicals, ~34 i5 sele-ted from hy-ogen and C(~_3) alkyl radicals and R33 is selected from hydrogen and methyl, and p is a whole number that varies rom 0 to 3. Preferably R3~ and R31 are sel2cted ~rom C~l 8j alkyl radicals and most preferably methyl, but they can be any of the radicals previously disclosed fvr the R radical. In addition, R38 and R40 may be selected from hydrogen and any of the C[1 8~
monovalent hydrocarboll radicals disclssed previously for ~30 and R31. Most preferably, ~hey ~re selected from C(l ~) alkyl radicals t phenyl radicals and vinyl radicals. Most preferably, R33, R34, R38 and R
are selected from hydrogen or alkyl radicals such as methyl~ The specific compound within the above for~
: mula which is preferred in ~he ins~ant invention has the formula NH~ CH2 CH2 Nl--CH2 - fH~c~o (CH2)3Si(OCH3)3 CH
~l 3 Such compounds may bP made by reacting ethylene-diamine with the approp1-.iate silylacrylate. Such silylacrylates are well known in the art and can be made by reacting the appropriate olefinic methacrylate com pound with a hydrotrialkoxysilane in the presence of a platinum catalystc The hydrogen of ~he silane will add 47 ~ 60SI-640 onto the olefinic group of the acrylate to produce an acrylate silyl compound, as disclosed, for instance, in Canadian Application Serial Number 375,687 of Keating, filed April 16, 1981. Such reaction takes place in the presence of a platinum catalyst at a temperature anywhere from room temperature to 150Co with or without a solvent at preferably ambient pressures. Once the acrylate silane is obtained than it can be reacted with appropriate amine in the presence of a solvent without catalyst to produce the desired amine acrylate adduct of Formula (L4) above for utilization as an adhesion promoter in the present invention. No catalyst is necessary for such a reaction, and temperatures anywhere from room temperature to 100Co can be used.
Pre~erably ambient pressures are utilized.
The desired amine acrylate adduct is produced in high yields.
This adhesion promoter is one of the adhesion promoters that can be utilized wi-th the White et al, Canadian Patent Applica-tion Serial Number ~04,9~9, filed June 11, 1982.
/_~
....~
~ 48 -Other adhesion promoters as they are developed may be able to be utilized in this composition in addion to the ones discloed in the prior case of Lucas et al., Canadian Patent Application Serial No. ~3J~ 1 filed ~ 9~It should be noted that the instant composition is low modulus, fast-curing and shelf stable in addition to its other pro perties and that this low modulus property of the composition is imparted to it by the plasticizers. I-t is also thixotropic in accordance with the addition of a thixotropic agent disclosed previously and is low cost iE the preferred extend-ing filler of the present case is utilized.
Any of the other adhesion promoters that were disclosed in Lucas et al. Canadian Appl~
Serial No. ~fS q filed ~ ~ ~ /J~ 19~
the present case, may be utilized. In addition, other additives as they are developed may be utilized in the compositions of the present invention.
To produce the low modulus, shelf-stable, fast-curing composition of the present case, i-t is desirable to form the polyalkoxy diorgano-2'i polysiloxane polymer Eirst. This may be done by reactillg the silanol polymer with a cross-linking agent o:E Formula (5~ in the presence of amine catalyst, preferably hexy].amine as disclosed in the foregoin~ Can ~pp. S~404,949 flled June 11/82, then taking ~ 33 60sl-S4~
. - 4g this product, adding ~he scavenger to it 50 as to absorb the hydroxy groups. The scavenger is preferably an ~une or a silaæ~.To this there is added the various additives as will be shown in the examples below. By this method, there is then produced a low modulus, o~e-comDonent RTV system which is low cost, is thixotropic and can also be made self bonding. ~ur~her, the compositlon has the properkies of being shelf stable and fas~ curina as disclosed in Whi~e et al.,Can~,Appl~ S.~404,949~
The examples given below are given for the purpose of ill ustratin~ the present inven~ion. They are not given for setting limits or boundaries to the instant inven-tion. All par~s are by weight.
_ampl.e 1 There was prepared a base composition comprising 100 .
parts by weight of a 150,000 centipoise methyldimethoxy-terminated dimethylpolysiloxane polymer, 0.5 parts of di~N-hexylamine, 35 par~s by weigh~ o trimethysiloxy end-stopped dimethylpolysiloxane polymer havinq a viscosity of 100 centipoise at 25C., 10 par~s by weight of a 3 mole percent trimethylsiloxy monofunctional uni~s, 20 mole percent methylsiloxy trifunctional units t and ~ 50 -77 mole percent dimethysiloxy difunc~ional units having a viscosity of 50 centipoise at 25~C. and ~5 weight ~ silanol. There was also mixed in this composi-tion, 130 parts of stearic acid trea~ed calcium carbonate sold under the trade name Hydro~arb 95T from OMYA, Inc.
of Vermont, 3 paxts of octamethylcyclo~etrasiloxane treated fumed silica .2 parts of a ~olyether sold under the trade name of UCON LB-114S by the ~nion Carbide Corporation, and 4.2 parts of methyldimethoxy ~-methyl-acetamidosilane. Such composition which was ~repared ina substantially anhydrous manner was fur~her mixed with a catalyst .in a substantially anhydrous manner in the concentrations shown in ~able I below. In Table I are given the flow properties, ~ack-free time, the applica lS tion rate and certain physical properties that re~
sulted from such RrrV compositions when they were cured.
The test for flow properties is deterrninecl by the 3Oei.ng Test and i5 as follows. A ver~ical jig is present with a cylindrical cavity on the top which .20 contains a plunger. The cavi~y is filled with sealant.
The ~lunger is then pushed level with the surface of the jig~ The instrument is then set in a vertical positio with the sealant pro~ruding 0O5 inches above the sur~
ace. The sag is then measured in ~exms of tenths o~
~ 60Si-6~0 of inches. The cavity i~ O.S inches deep and 1.5 inches in diameter.
The tack-free time is determined by making an approximately one inch by five inch by lJ8 lnch smear S of the sealant and ~hen determi.oina the time the sur-face is dry to the touch of the finger.
The application rate i5 determined by filling a 6 oz~ Semco tube affixed with a 1/8 inch diameter orifice. The application rate is hen run under 90 psi air pressure as supplied by an air tank. The measurement is made in ter~s of grams per minute o delivered sealant.
The test resul s are set forth ~n Table I below.
35~3~3 `
- ~2 -TABLE ~
A B
Base 100 100 Dibutyltindiacetate 0.4 0.4 Methyldimethoxy N-methylacetamido silane --- 1.0 Flow, inches 0.5 Tack-free time, minutes~3 20 Application rate, g.~min. 14 360 Shore A, hardness 15 18 Tensile/ psi 268 275 Rlongationt ~ 990 g25 le 2 There was prepared a base composition comprising 100 parts by weigh~ of a methyldimethoxy-termi.rlated di-metnylpolysiloxane polymer ha~î.ng a v.iscosity of 150,000 centipoi~e at 25C~, 0.5 parts of di-N-hexylamine, 35 parts of 100 centipoi~se at 25 C. trimethylsiloxy end-stopped dimethylpolysiloxarle fluid, 10 parts o the same trifunctiona~ fluid as in Exam le 1 J 130 arts of ~ .2 ~ ~ 5 U~O~-LB-1145, the samecalcium cIrbonate identified in Example 1,/and 3.0 par~s of octamethylcyclote~rasiloxane treated fumed silica of a surface area of approximately 200 meters square per gram. To this base comPosi~ion, there was -- 53 . .
added various amounts of me~hyldimethoxy ~l-methylacetamido silane and dibutyl tin acetate as wPll ~as a standard amount of adhesiolrl promoter indicat~d in Table II below. The ~dhesion promoter had the formula, The samples were tested for tack-free time as this test was utilizetl in ~xample 1. The results are set forth in Table II below for the various compositionsO
~AsLE ~ I
A B C D E F
Base 100 100 100 lOû 100 100 ~thyldimethoxy-N~n~ tlyl 2 . 0 2 . 5 3 . 0 3 . 5 4 . O 4 . 5 acet~TIidosilane Dibutylt.Lndiacetat~O ~ 3 0 0 3 0 . 3 0 . 3 0 . 3 0 . 3 A~sic n Prc~noter 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 lS In~tial DuraT~ter 23 24 24 2S 27 24 48 hrs.tlOO~C.Du~cxneter 0 0 22 28 27 28 Initial Tack F~Pe Tin~ 24 24 25 25 2g 43 Im~n. ) 4~ ;. /100C. ~ra~k No ~ ~0 1~ ~2 ~1 ~20 E'ree r~ (mLn. ~ e Cure 3~
Example_3 The same base composition as in Example 2 was utilize~
in this example. This base composition was catalyzed with the scavenger, catalyst system and adhesion promoter with the evaluated tack-ree times shown in Table III below.
TAsLE III
A B C D E F G H
Base 100 100 100 100 100 100 100 100 Hexamethyldisilazane 1.7 --- --- --- --- --- --- ---t-~utoxydimethyl~
isopropylaminosilane -- 3.0 --- --- - - --- --- ---Bis-(dimethylamino3-dimethyl~ilane ~ 1.7 --~ --- --- ~-- 1.7 Bis-(diethylamino~-dimethylsilane --- --- --- 1.7 ---Bis-(dimethylamino~-diphenylsilane --- --- --- --- ~. ~~~ ~~~ ~~-Bis-(monoethylamino~-dimethylsilane --- -~- --- -- --- 1.7 --- ---Bis-(mono-n-butyl-amino)-dime~hyl-silane --~ --- --- -- --- --- 1.7 Adhesion promo~r (ethylene-diamine-methacryloxypro-~5 pyl tr.imethoxy-silane adduct~ 1.0 1.0 1.0 1.0 1.0 1.0 1.0 ---Di.butyltindiacetate 0.3 ~.3 0.3 0.3 0.3 0.3 0.3 0~3 Methyltrimethoxysi-lane 2.5 2.5 2~5 2.5 2.5 2.5 2.5 2.5 Initial durometer 25 25 26 26 26 20(1)25 q8 hrs~/100CO
aging durometex 27 23 24 27 0 23 26 Initial ~FT -minutes 26 16 ~0 21 15 14 1~ 30 48 hxs.JlOO~C~Ag.ing 15 14 ~ 13 No 14 13 No TFT Cure Cure ~19 Air was entrapped in these samples durinq catalyzation.
.. . . .. . . . ~
., o -~
- 55 _ The following conclusions that were reached as a result of the above test were that the adhecion promoter (the ethylenediamine-methacryloxypropyltrimethoxysilane adduct) helped stabilize the formulation and that the bis-~dimethylamino) diphenylsilane is a poor scaven~er~ Theremaining materials appear to function effectively as scavengers.
F ~ 4 There was prepared a base compound comprising 100 parts by weight of a methyldim~thoxysiloxy-te~minated di~
methylpopysiloxane polymer of 150,000 centipoise viscosity, at 25C. in which there was oresent 0.5 parts of di-n-hexyl-amine and into which was mixed 35 parts by weight o~ the same trimethylsiloxy~terminated polydimethylsiloxane poly-mer o ~xample 1, 10 parts by weiaht of the same trifunc-tional fluid of Example 1, 180 parts by weight of the same stearic acid treated carbonate as Example 1, and .2 parts by weight of the ~CON I.B 1145. Such basecompounds were catalyzed with various amounts of ethylenediamirle-meth-acryloxypropyltrimethoxysilane adduct and dibutyltindi~acetate and with various scavengers. The physical ~roper-ties of the initial samples as well as the tack-free time of the aged samples of the composition with test results are given in Table I~ below. The difference in the tack-free time between th~ i~itial sample and the one that hasbeen subjected to an accelerating aginq i~ a measure of 3~ - `` - --
function21 fluid that will be discussed below will be sub-stantially the same as expressed in terms of either polymersystemO
~ ccordingly, per 100 parts by weight of the base orqano-~olysiloxane polymer there m~y be utilized from 5 to 60 parts by weight of a second plasticizer which is a linear triorganosiloxy end-sto~ped diorganopolvsiloxan-e polymer of a viscosi~y varying from 10 to 20, noo centi~oise at 25C.
and in which the organo grou~s are selected from C(l 8) monovalent hydrocarbon radicals, More preerably, these monovalent hydrocarbon radicals are a].kyl radicals of 1 to 8 carbon atoms. Thus, preferably, the s~cond plasticizer has ~he formula R
R - sio ~ SiO - ~ R20 (11) l20 ~ l20 t where R20 is a monovalent hydrocarbon radical~ ~referably an alkyl or phenyl radical of C(l ~ carbon ato~s or genexal~y ~o Ctl 8) alkyl or aryl radical~a~ varies such that the vis-coslty of the polymer varies from 10 ~o 20, ono centipoise at 25C. Most preferably, the R group is ~ethyl and the polymer has a viscosity varying from 10 ~o ln, ooo centipoise at 25C. more pre~erably having a viscosity varying from 10 to 1000 cPntipoise at 25~C. Generally, such polymers by ~he way they are made have from 500 to 1500 parts OH.
per mi~lion of silanol as/ The general process for producing such plasticizer of ~ormula ~11) above is to hydrolyze ~he appropriake chlorosilanes. ~hus~ triorganochlorosilane i5 hydrolyzed with diorg~nodichloxosilane in water, then th~
hydrolyzate is removed and purified by decantation and other procedures used to result in the desired linear d~-organopolysiloxane polymer of Formula (11). Such a pol~nerjust by thi5 natural hydrolysis method has usually 500 to 1500 parts per million of silznol as 0~l r and may be further purified by other procedures. However 9 this is not normally done because of the expense~ Further, such silanol groups or hydroxy groups will not cause difficulty in the presen~ situat.ion if there is a scavenge.r that absorbs substantially all such hydxoxy groups that ar~ pre~ent in such a polymer. As noted pre-vio~lsly, there has to b~ ut.ili~ed a scavenger in the instant system that absorbs all the free hydroxy groups in such a plasticizer.
As noted previously~ in order to get the Modulus of the compositiQn to a desirably low level, there has to be utiliz~d two pl~sticlzers since the trifunctional fluid . 60SI-640 ; ~ 3~ -alone will not give both the maximum decrease i~ vis cosity and modulus. Thus, if it is desired to obtain the lowest modulus, maximum adhesion and minimum vis-oosity ~o increase the ease of application of the sealant, it is necessary to use both plasticizers.
Accordingly, the most ~referred low modu1us, one-component RTV systems of the pres~nt case are pro-duced by utilizing the two plasticizers of the present invention in ~he foregoing propor~ions shown above.
~t should ~e noted that within the above bxoad ranae - of the second plasticizer of from 5 to 60 parts, there may preferably be utilized a concentration of 20 to 45 parts by wei~ht.
Another aspect of the present composition is that is low cost. The composition may be made low cost by incorporating in it anywhere from 50 to 300 parts or more by weight per 100 parts of ~he base or ganopolysiloxane of an extending filler~ An extending filler is desirably in the composition since it lowers ~0 the cost of the composition~ and adds to the s~renqth of the composition without detracting from i~s low modulus properties. Most preferably, the filler is calcium carbonate. The most desirable calcium car-bonate is the one that is ~rea~ed wi~h stearic acid.
~ 5~33 This giv~s the best flow properties ~o the uncured com-position of the present case and the best l-ow modulus properties specifi2d previouslyO Other extending fillers may be incorporated into the presen~ composition in the foregoing concentrations of calcium carbonate that have been disclosed above. Thus, other extending fillers and reinforcing fillers that may be utiliæed ~n various concen~rations, are for example, ti~anium dioxide, zirconi~m silica~e, silica aero~el, iron oxide, diatomaceous earth, fumed silica, carbon black, precipitated silica, galss fibers, polYvinyl chloride, ground quartz, ete. Th~ amoun~s of filler used can ob viously be varied within wide limits in accordance with the intende~ u~e. For example, in some sealant appllca-tions, the curable compoisitons Eor making bindingmaterial on a weight basis, as much as 700 parts or more o fillex, per lO0 parts of or9ano.Dolysiloxane can be employed. In such applications, the filler can con-sist of a major amount of extending matexials, such as yround quartz, polyvinylchloric~e, or mi~tures thereof, prefexably having arl average particle size in the range of from a~out l to lQ microns.
3~
The compositions of the present invention also can be employed as construction sealant~ znd caul~in~
compounds. The exact am~unt of fi.ller, therefore, will depend upon such factors as he application for which the organopolysiloxane composition is in~ended, the type o~ fillex utilized (that is, the density of the filler and ~s particle sizc~. Preferably~ a proportion of from 1 to 300 p2rt5 of filler, which can includ~ up to about 20 par~s of a reinorcing filler, such as fumed silioa filler, per lOa par~s of silanol-terminated organopolysiloxane is utilized.
However~ the iller~ utilized at a concentration of 50 to 300 parts by weight should be an extending iller such as calcium carbonate Por the low moduluc compositions of the present case. In addition to the extending flller, there is utili~ed from I to 50 parts and preferably fxom 1 ~ 10 parts by weight per 100 par~s o~ the base organopolysiloxane polymer of a reinforcing E.iller. The reinforclng filler may he selecte~ from precipl~ated silica~ and Pumed silica, and is most preferably fumed sillca. More preferably, 3~ -there is utilized a fumed silica ~ha~ is t.rea~ed either with cyclopolysiloxanes as disclosed in Lucas, U.SO
Patent 2,938,009 or with silazaries as disclosed in Smith, ~.S~ Paten~ 3,635,743. More pr~ferably, there is utilized from l to lO parts by weigh~ of said ~reated fumed sillca treated with cyclopolysiloxanes. Such fumed silica acts as a sa~ control agent ~o make ~he composition thixo~ropic. Thixo~xopic means that the composition when put on a vertical plane will no~. flow in the uncured sta~e, or will have only minimal flowO
Another way of making the composition thixotropic is as disclosed in Lampe~ et al., U.S. Patent 4,261,758 dated A~.ril 14, 1981. . .
Thus, per 100 parts of the base organopolysilo~ane polymer with the reinforcing fumed silica, and in addition to the ex~endina filler, ~here may be .incorporated in the RTV composition from .l ~o 2.0 parts by weight per lO0 parts by weight of the oxganopolysiloxane of a second sag con~rol agent whioh is a polye~her selec~ed from ~0 the Eormulas con~isting oE
A O (C~H2XO)~ B (12 , ~
:
and [A ~ (CxH2x)n ~ z (13) where A and B represent radlcals select.ed from the class consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cyclo alkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals and mono-nuclear aryl lower alkyl radicals wherein the alkyl gxoups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
o Il R - C - O ~ -where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethyl.olpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; y has a value of from 2 to 10; and æ has a value of from 1 to 5; n is an integer equal to from 4 to 20,000; the po:l.yether having a molecular weight of from about 300 to abou-t 200,000~
The polyether which is a sag control agent may be utili.zed in addition to the fumed silica or in place of it ~S~3~
. 60SI-640 to impart thi~otropic properties -to the uncured RTV
composition which is desired in a sealant. It must be noted that the preferred RTV composition of the present case, that is, non-corrosive, low modulus, fast-curing, shelf-stable low modulus is very desirable as a sealant in constructing buildings, in glazing applications and in ot~er manufacturing sealant applications. Accoringly, it is highly desirable that such sealant be thixotropic, that is when it is inserted in the uncured state in a creviee, it will not flow. Such thixotropy may be incorporated in the present composition by the utilization of fumed silica in small quantities in combination with the above polyethers. Further the polyethers are present at preEerably from .1 to lo0 parts by ~eight, in com-bination with the fumed silica. Although the fumeclsilica will provide sag control properties to the com-positions, these properties are considerably enhanced with the incorporation of the polyether. For more information as to the use of the polyethers as a sag control agent, one is referred to the disclosure of Lampe et al., U.S. Patent 4,261,758 dated ~pril 14, lg81 .
Examples of commercially available polyethers which may be utilized in the present invention are such polyethers as Pluracol V-7 sold by the Wyandotte Chemicals Corporation, and UNCON LB-1145 sold by the Union Carbide Corporation of Connecticut.
In place of both of these sag control or in acldition to them, there may be utilized per 100 parts by weight - 4~ ~ .
of the base organQpolysiloxane of rom . 2 ~o 2. 0 parts and more preexably from ~ 2 to 1. 5 par~s by weight of a hydrog-enal:ed castor oil.
~ n example of hydrogenated castor oil t~at may be utilized as a sag controï agent is onP known as Thixcin (tradename of NL Chemicals, Heightstown, N.J~) ~ ccordingl~, when a hydrogenated castor oil is utilized as a sas co~trol agent, ne.itherthe fumed silicz o~ ~he poly~
eth~r has to b~ utili~ed. However, when the hydrogenated ca~tor oil is no~ utilized as a sag control a~en~, ~hen ~here should be utilized the ~umed silica with the polyether.
~s an alternative thc fumed 5i lica or polyeth~r may be used alone. Please note that it must be emphasized that a reinor~ing filler is neither necessary nor desired in the present composition since it is desired to make the compositiorl low modulus~ ~ reinforcing filler in large quantities will undesirably increase the modulus of the present compos:itio~ ost ~referably, the fumed silica if ~o used is used in addition to the extending :Eil:ler such as calcium carbonate and specifically stearic acid treated cal~
cium carbonate ~hich reduces the cost of the composi~io~, keeps the viscosity o~ the uncured composition and the modulus of the uncured composition at a low level~ There may be added various other types of additives to the composition as they ~ecome available or as they are invented.
3 60Si-6~0 _ 45 -Thus, ~ may ~e incorporated into the present com~
position per 100 par~s of the organopolysiloxan2 of .1 to lO parts by weight of an adhesion ~romoter. The present compositions, that is the composition of the White et al.
Can ap~l-s N-404~949~ do not bcnd very well to substrates, Accordingly9 it is desirable to utilize a primer with such compositions or an adhesion promoter. The primers are wldesi.rable in that they add ad~itional labor costs to the applica~ion of the sealant. Accordingly, i~ is highly desirable tha there be u~ilized or incorporated into the composition a self-bonding additive. For in-stance, note the recitation of self-bondin~ additives as dis losed i.n Lucas et al.,Canadian ~r)li.cation Serial No. ~ ~ ~S 9 filed ~ ~ JI~
An additional self-bondinq additive that may be utilized in the compositions of the present case is one that may be present from .1 to lO ~arts by wei~ht of an adhesion promoter whlch has the formula R31 R33 R34 R3~
tR3~ Si ~ R32 _O ~ C ~ CHc~2 ~N ~ R ~ N ~ R ~14) where R30, R are selected from C(~_~3 monovalent hydro-carbon radicals, R32, R36 are selec~ed from C~ 23 di-vale~t hydrocarbon radicals, R38 and ~40 are selected from the class consisting of hydrogen and C(l ~ mono~
valent hydrocarbon radicals, ~34 i5 sele-ted from hy-ogen and C(~_3) alkyl radicals and R33 is selected from hydrogen and methyl, and p is a whole number that varies rom 0 to 3. Preferably R3~ and R31 are sel2cted ~rom C~l 8j alkyl radicals and most preferably methyl, but they can be any of the radicals previously disclosed fvr the R radical. In addition, R38 and R40 may be selected from hydrogen and any of the C[1 8~
monovalent hydrocarboll radicals disclssed previously for ~30 and R31. Most preferably, ~hey ~re selected from C(l ~) alkyl radicals t phenyl radicals and vinyl radicals. Most preferably, R33, R34, R38 and R
are selected from hydrogen or alkyl radicals such as methyl~ The specific compound within the above for~
: mula which is preferred in ~he ins~ant invention has the formula NH~ CH2 CH2 Nl--CH2 - fH~c~o (CH2)3Si(OCH3)3 CH
~l 3 Such compounds may bP made by reacting ethylene-diamine with the approp1-.iate silylacrylate. Such silylacrylates are well known in the art and can be made by reacting the appropriate olefinic methacrylate com pound with a hydrotrialkoxysilane in the presence of a platinum catalystc The hydrogen of ~he silane will add 47 ~ 60SI-640 onto the olefinic group of the acrylate to produce an acrylate silyl compound, as disclosed, for instance, in Canadian Application Serial Number 375,687 of Keating, filed April 16, 1981. Such reaction takes place in the presence of a platinum catalyst at a temperature anywhere from room temperature to 150Co with or without a solvent at preferably ambient pressures. Once the acrylate silane is obtained than it can be reacted with appropriate amine in the presence of a solvent without catalyst to produce the desired amine acrylate adduct of Formula (L4) above for utilization as an adhesion promoter in the present invention. No catalyst is necessary for such a reaction, and temperatures anywhere from room temperature to 100Co can be used.
Pre~erably ambient pressures are utilized.
The desired amine acrylate adduct is produced in high yields.
This adhesion promoter is one of the adhesion promoters that can be utilized wi-th the White et al, Canadian Patent Applica-tion Serial Number ~04,9~9, filed June 11, 1982.
/_~
....~
~ 48 -Other adhesion promoters as they are developed may be able to be utilized in this composition in addion to the ones discloed in the prior case of Lucas et al., Canadian Patent Application Serial No. ~3J~ 1 filed ~ 9~It should be noted that the instant composition is low modulus, fast-curing and shelf stable in addition to its other pro perties and that this low modulus property of the composition is imparted to it by the plasticizers. I-t is also thixotropic in accordance with the addition of a thixotropic agent disclosed previously and is low cost iE the preferred extend-ing filler of the present case is utilized.
Any of the other adhesion promoters that were disclosed in Lucas et al. Canadian Appl~
Serial No. ~fS q filed ~ ~ ~ /J~ 19~
the present case, may be utilized. In addition, other additives as they are developed may be utilized in the compositions of the present invention.
To produce the low modulus, shelf-stable, fast-curing composition of the present case, i-t is desirable to form the polyalkoxy diorgano-2'i polysiloxane polymer Eirst. This may be done by reactillg the silanol polymer with a cross-linking agent o:E Formula (5~ in the presence of amine catalyst, preferably hexy].amine as disclosed in the foregoin~ Can ~pp. S~404,949 flled June 11/82, then taking ~ 33 60sl-S4~
. - 4g this product, adding ~he scavenger to it 50 as to absorb the hydroxy groups. The scavenger is preferably an ~une or a silaæ~.To this there is added the various additives as will be shown in the examples below. By this method, there is then produced a low modulus, o~e-comDonent RTV system which is low cost, is thixotropic and can also be made self bonding. ~ur~her, the compositlon has the properkies of being shelf stable and fas~ curina as disclosed in Whi~e et al.,Can~,Appl~ S.~404,949~
The examples given below are given for the purpose of ill ustratin~ the present inven~ion. They are not given for setting limits or boundaries to the instant inven-tion. All par~s are by weight.
_ampl.e 1 There was prepared a base composition comprising 100 .
parts by weight of a 150,000 centipoise methyldimethoxy-terminated dimethylpolysiloxane polymer, 0.5 parts of di~N-hexylamine, 35 par~s by weigh~ o trimethysiloxy end-stopped dimethylpolysiloxane polymer havinq a viscosity of 100 centipoise at 25C., 10 par~s by weight of a 3 mole percent trimethylsiloxy monofunctional uni~s, 20 mole percent methylsiloxy trifunctional units t and ~ 50 -77 mole percent dimethysiloxy difunc~ional units having a viscosity of 50 centipoise at 25~C. and ~5 weight ~ silanol. There was also mixed in this composi-tion, 130 parts of stearic acid trea~ed calcium carbonate sold under the trade name Hydro~arb 95T from OMYA, Inc.
of Vermont, 3 paxts of octamethylcyclo~etrasiloxane treated fumed silica .2 parts of a ~olyether sold under the trade name of UCON LB-114S by the ~nion Carbide Corporation, and 4.2 parts of methyldimethoxy ~-methyl-acetamidosilane. Such composition which was ~repared ina substantially anhydrous manner was fur~her mixed with a catalyst .in a substantially anhydrous manner in the concentrations shown in ~able I below. In Table I are given the flow properties, ~ack-free time, the applica lS tion rate and certain physical properties that re~
sulted from such RrrV compositions when they were cured.
The test for flow properties is deterrninecl by the 3Oei.ng Test and i5 as follows. A ver~ical jig is present with a cylindrical cavity on the top which .20 contains a plunger. The cavi~y is filled with sealant.
The ~lunger is then pushed level with the surface of the jig~ The instrument is then set in a vertical positio with the sealant pro~ruding 0O5 inches above the sur~
ace. The sag is then measured in ~exms of tenths o~
~ 60Si-6~0 of inches. The cavity i~ O.S inches deep and 1.5 inches in diameter.
The tack-free time is determined by making an approximately one inch by five inch by lJ8 lnch smear S of the sealant and ~hen determi.oina the time the sur-face is dry to the touch of the finger.
The application rate i5 determined by filling a 6 oz~ Semco tube affixed with a 1/8 inch diameter orifice. The application rate is hen run under 90 psi air pressure as supplied by an air tank. The measurement is made in ter~s of grams per minute o delivered sealant.
The test resul s are set forth ~n Table I below.
35~3~3 `
- ~2 -TABLE ~
A B
Base 100 100 Dibutyltindiacetate 0.4 0.4 Methyldimethoxy N-methylacetamido silane --- 1.0 Flow, inches 0.5 Tack-free time, minutes~3 20 Application rate, g.~min. 14 360 Shore A, hardness 15 18 Tensile/ psi 268 275 Rlongationt ~ 990 g25 le 2 There was prepared a base composition comprising 100 parts by weigh~ of a methyldimethoxy-termi.rlated di-metnylpolysiloxane polymer ha~î.ng a v.iscosity of 150,000 centipoi~e at 25C~, 0.5 parts of di-N-hexylamine, 35 parts of 100 centipoi~se at 25 C. trimethylsiloxy end-stopped dimethylpolysiloxarle fluid, 10 parts o the same trifunctiona~ fluid as in Exam le 1 J 130 arts of ~ .2 ~ ~ 5 U~O~-LB-1145, the samecalcium cIrbonate identified in Example 1,/and 3.0 par~s of octamethylcyclote~rasiloxane treated fumed silica of a surface area of approximately 200 meters square per gram. To this base comPosi~ion, there was -- 53 . .
added various amounts of me~hyldimethoxy ~l-methylacetamido silane and dibutyl tin acetate as wPll ~as a standard amount of adhesiolrl promoter indicat~d in Table II below. The ~dhesion promoter had the formula, The samples were tested for tack-free time as this test was utilizetl in ~xample 1. The results are set forth in Table II below for the various compositionsO
~AsLE ~ I
A B C D E F
Base 100 100 100 lOû 100 100 ~thyldimethoxy-N~n~ tlyl 2 . 0 2 . 5 3 . 0 3 . 5 4 . O 4 . 5 acet~TIidosilane Dibutylt.Lndiacetat~O ~ 3 0 0 3 0 . 3 0 . 3 0 . 3 0 . 3 A~sic n Prc~noter 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 lS In~tial DuraT~ter 23 24 24 2S 27 24 48 hrs.tlOO~C.Du~cxneter 0 0 22 28 27 28 Initial Tack F~Pe Tin~ 24 24 25 25 2g 43 Im~n. ) 4~ ;. /100C. ~ra~k No ~ ~0 1~ ~2 ~1 ~20 E'ree r~ (mLn. ~ e Cure 3~
Example_3 The same base composition as in Example 2 was utilize~
in this example. This base composition was catalyzed with the scavenger, catalyst system and adhesion promoter with the evaluated tack-ree times shown in Table III below.
TAsLE III
A B C D E F G H
Base 100 100 100 100 100 100 100 100 Hexamethyldisilazane 1.7 --- --- --- --- --- --- ---t-~utoxydimethyl~
isopropylaminosilane -- 3.0 --- --- - - --- --- ---Bis-(dimethylamino3-dimethyl~ilane ~ 1.7 --~ --- --- ~-- 1.7 Bis-(diethylamino~-dimethylsilane --- --- --- 1.7 ---Bis-(dimethylamino~-diphenylsilane --- --- --- --- ~. ~~~ ~~~ ~~-Bis-(monoethylamino~-dimethylsilane --- -~- --- -- --- 1.7 --- ---Bis-(mono-n-butyl-amino)-dime~hyl-silane --~ --- --- -- --- --- 1.7 Adhesion promo~r (ethylene-diamine-methacryloxypro-~5 pyl tr.imethoxy-silane adduct~ 1.0 1.0 1.0 1.0 1.0 1.0 1.0 ---Di.butyltindiacetate 0.3 ~.3 0.3 0.3 0.3 0.3 0.3 0~3 Methyltrimethoxysi-lane 2.5 2.5 2~5 2.5 2.5 2.5 2.5 2.5 Initial durometer 25 25 26 26 26 20(1)25 q8 hrs~/100CO
aging durometex 27 23 24 27 0 23 26 Initial ~FT -minutes 26 16 ~0 21 15 14 1~ 30 48 hxs.JlOO~C~Ag.ing 15 14 ~ 13 No 14 13 No TFT Cure Cure ~19 Air was entrapped in these samples durinq catalyzation.
.. . . .. . . . ~
., o -~
- 55 _ The following conclusions that were reached as a result of the above test were that the adhecion promoter (the ethylenediamine-methacryloxypropyltrimethoxysilane adduct) helped stabilize the formulation and that the bis-~dimethylamino) diphenylsilane is a poor scaven~er~ Theremaining materials appear to function effectively as scavengers.
F ~ 4 There was prepared a base compound comprising 100 parts by weight of a methyldim~thoxysiloxy-te~minated di~
methylpopysiloxane polymer of 150,000 centipoise viscosity, at 25C. in which there was oresent 0.5 parts of di-n-hexyl-amine and into which was mixed 35 parts by weight o~ the same trimethylsiloxy~terminated polydimethylsiloxane poly-mer o ~xample 1, 10 parts by weiaht of the same trifunc-tional fluid of Example 1, 180 parts by weight of the same stearic acid treated carbonate as Example 1, and .2 parts by weight of the ~CON I.B 1145. Such basecompounds were catalyzed with various amounts of ethylenediamirle-meth-acryloxypropyltrimethoxysilane adduct and dibutyltindi~acetate and with various scavengers. The physical ~roper-ties of the initial samples as well as the tack-free time of the aged samples of the composition with test results are given in Table I~ below. The difference in the tack-free time between th~ i~itial sample and the one that hasbeen subjected to an accelerating aginq i~ a measure of 3~ - `` - --
6 0S I - 6 ~1 0 of the shelf stability of ~he compound. If the tack-free time does not measurably chanae ater accelerated aging then the compound has good shelf stab~ IityO The results may be seen in Table IV below.
TP~:BLE IV
Base lOQ 100lOû 100 100 100 100 100 100 Ethylenediamine~
s methacryloxy- , -p~pylt~i-methoxysilane : adduct 1.0 --~ 1.0 Di~utyltin-diacetate 0.3 0.3 0.3 0.3 0.3 0.3 0.3 C.3 0.3 Methyltri-methoxy-silane 2.5 2.5 2.5 2~5 2.5 2~5 2.5 205 2O5 B.is-~dimethyl-amino) di methylsilane -~- 1.7 1.7 2.2 207 3.2 3~Z
~is-~rnono-ethylamino-dimethyl-silane --~ -- 3.2 3.7 Xnitial Physicals Tack free time, minutes 33 25 26 20 23 22 22 23 21 Shore A, 2S hardness 34 22 26 21 21 21 20 23 20 Tensile, psi. '~12 157 138 147 133 128 116 105 103 Elongation,~ 280 390 350 390 390 360 350 380 340 4~ hrs~/100C. Accelerated_~e Tack free time~ min. No No 23 No No Semi Semi 20 20 Shore A, Cure Cure lS Cure Cure Cure Cure 23 25 har~nes 5 3~
The data above indicates ~hat low modulus composi~ions were obtained which had good shelf stability.
The above da~a also indicates ~ha~ bis-(dimethyl-amino)~dimethylsilane is a poor scavenger while the S ethylenediamineme~hacryloxypropyltximethoxysilane adduct i5 not a shelf stabili~y agent by itself but does promote shelf~stability with a poor sca~bnger like bis ~dimethyl-amino)dLmethylsilane.
Bi~-(monoethylamino)dimethylsilane is an excellent : 10 scavenger.
Exam~le 5 A base compound was prepared as in Example l in whi.ch the base me~hyldimethylpolysiloxane polymer was the in w~ch there was present 0~5 parts of di-n-hexyl~ne same as Exampl~ l/to which was added 15 parts of the same trifunctional fluid as Example l, 35 parts by weight of the same trimethylsilyl~terminated po].ydimethylsiloxane as Example l, 185 parts of ~he same stearic acid treated calcium carbonate as i.n Example l and .2 paxts of Pluracol V-7 whlch is a polyether sag control agent sold by the .0 Wyandotte Chemicals Corporation. As in all the exam-ples, lO0 parts of the base compounds were catalyzed with various amounts o~ scaven~er cross~linking agent, conden-sation catalyst and self-bondlng additives in a sub . ll95B33 60Si-640 - 59 _ .
stantially anhydrous manner~ Preferably such mixing in _ pressure all cases was carried out in a Semco ~ /mixer in an anhydrous manner. The concentration of the ingredients mixed into the base compound as well as the physical properties obtained from their particular composition are shown in Table V below.
TA~LE V
_ A B C D
Base 100 100 100100 ~examethyldisilazane 2.0 2.0 ~.22.0 Methyltrimethoxysilane ~ 4.0 Dibutyltindiacetate 0.075 0.075 0.0750.1 Aminoethylaminopropyltri-methoxysilane 1.0 1.0 1.01 0 Pro~erties 5hore A, hardness 12 25 10 30 Tensile, psi 119 207 103153 Elongation, ~ 650 410 640230 Application rate 9 g. /min.
20 Tack free time, minutes ~Initial) 11 12 10 19 (20 hrs.~100UC. ac-celerated) 13 13 8 18 Peel adhesion, lbs./in.
~S Cohesive Failure (Concrete~ 7/10* 8/10 28/90 56/100 *Semi-cured at interface~
33 -~
As the results of Table V indicate the composition has good low modulus, ~ood self~bondin~ proper~ies and good shelf stability. Other conclusions that can be drawn from this data is that the level of ~rimethylme~hoxysilane in the product had a very pronounced effect on the cross-link density as shown by the difference in Duromet~r measure yoing from 0 ~o 1 to 4 parts. The ~urometer goes fro~l 12 to 2S to 30. It can also be appreciated that the h.ighest peel adhesion values obtained from concrete are o~tained at ~he 4 part level of the methyltrimethoxy-sila~e~
Example 6 There was prepaxed a base compound comprising 1.00 parts of the same dimethoxymethylsiloxy-terminated dimethyl~
0.5 parts of di-n~ laminP
siloxane polymer of Example 1,/35 pa.rts b~ weight of a tri-methylsiloxy-terminated polydimethylsiloxane of 100 centipoise viscosity at 25C. of Example 1, 10 parts by weight of the same txifunctional fluid as Exampl~ 1~
145 parts of the sam~ stearic acid ~reated calcium car-bonate of Example 1, and 3 parts by weight of the sametreated fumed silica as Example 1. A 100 parts of such base compound W2S cataly2ed withv arious amo~nts of scavenger, cross-linkin~ aaent, catalyst, and self-bondin~ additiv~s as shown in Table VI below. The physical properties of such examples, shelf-aging properties, that is the tack free time of such S samples, and the peel-adhesion values are shown in Table IV below.
TABLE VI
A B C
Base (above) 100 100 100 Hexamethyldisilazane 2.5 2.5 3.0 Methyltrimethoxysislane 0.5 0.25 0.5 Dibutyltindiacetate 0~075 0.075 0O075 Aminoethylaminopropyltri-methoxysilane 1.0 1.0 1.0 Pro~erti~
Shore A, hardness 16 15 20 TensiLe, psi. 231 140 194 Elongation, ~ 630 630 570 Application rate, g./min. 269 ~41 313 Tack free timer minutes 11 5 6 Peel Adhesion, lbs./in.
% Cohesive Failure (Cuxe 10 days at 50Q~ R.H./77F) (1) Anodized aluminum43/100 42/100 47/100 (2) Lexan 5/S 42/100 48/95 ~S (3) P~C Sl/l~0 ~4/100 50/100 (4) Glas~
(5) Polyacrylate 6/1 7/3 4~0 (6) Conor~te* 13/90 11/95 13/93 ~7) Andersen Terrestone *All of the concrete specimens werP semicured at the substrate interface.
~3 3 3 ~ 62 -Example 7 o~
Th~re were prepared a ~ase compound/100-parts of the same dimethox~methylsiloxy dime~hylsiloxan~ poly~er containin~ 0.5 parts of di-N-he~ylamune of Example 1,~5 par~s of the same trimethylsiloxy dimethylpolysiloxane of Example ]., 10 parts of t.he same tri-functi.onal fluid of Example 1, 140 parts of the sarne stearic acid tre2ted calciulu carbonate of Example 1, 3 part~ of the same txeated umed silica of Ex~mple 1, and .2 parts of polyether sold under the name of Pluracol V-7 by the Wyandotte Chemieals Corp-oration. To 100 parts of such compound there was added various amounts of scavenger, cross linki.ng agent, condensation catalyst and self-bonding additive. The physical properties as well as th~ concentration of ingredients and the peel adhesion results are shown in Table VII ~elow~
TABL~ VII
A B C
Base II 100 100 100 Hexamethyldisila~ane 2.5 2u5 3.0 Methyltrimethoxysilane 0.5 0.25 0O5 Dibutyltindiacetate 0.075 0.075 0.075 Aminoethyle~hylamino-propyltrimethoxysilalle 1.0 1.0 1.0 Example 7 (cont. ) Table VII (cont. ~
A B C
Properties Shore A, hardness 17 12 16 Tensile, psi. 199 1~3 1~7 Elongation, % 50~ 680 600 Application rate, g./min, 294 290 314 T~c~ free time, minutes 5 7 5 Peel Adhes on, lb~,/in -~ Cohesive Pailure ~:ured fox ten days 50~ R.H.~77~F~
(1) Anodized aluminum 4~/100 47/100 Sl/100 (2) Lexan 5/0 10/22 3/1 (3) PVC 51/100 47/100 51/lQ0 (4) Glass 4~93 42/93 50/95 (5) Polyacryla~e 4/0 5/0 3/0 (6) Concrete 15/93 15/97 12/95
TP~:BLE IV
Base lOQ 100lOû 100 100 100 100 100 100 Ethylenediamine~
s methacryloxy- , -p~pylt~i-methoxysilane : adduct 1.0 --~ 1.0 Di~utyltin-diacetate 0.3 0.3 0.3 0.3 0.3 0.3 0.3 C.3 0.3 Methyltri-methoxy-silane 2.5 2.5 2.5 2~5 2.5 2~5 2.5 205 2O5 B.is-~dimethyl-amino) di methylsilane -~- 1.7 1.7 2.2 207 3.2 3~Z
~is-~rnono-ethylamino-dimethyl-silane --~ -- 3.2 3.7 Xnitial Physicals Tack free time, minutes 33 25 26 20 23 22 22 23 21 Shore A, 2S hardness 34 22 26 21 21 21 20 23 20 Tensile, psi. '~12 157 138 147 133 128 116 105 103 Elongation,~ 280 390 350 390 390 360 350 380 340 4~ hrs~/100C. Accelerated_~e Tack free time~ min. No No 23 No No Semi Semi 20 20 Shore A, Cure Cure lS Cure Cure Cure Cure 23 25 har~nes 5 3~
The data above indicates ~hat low modulus composi~ions were obtained which had good shelf stability.
The above da~a also indicates ~ha~ bis-(dimethyl-amino)~dimethylsilane is a poor scavenger while the S ethylenediamineme~hacryloxypropyltximethoxysilane adduct i5 not a shelf stabili~y agent by itself but does promote shelf~stability with a poor sca~bnger like bis ~dimethyl-amino)dLmethylsilane.
Bi~-(monoethylamino)dimethylsilane is an excellent : 10 scavenger.
Exam~le 5 A base compound was prepared as in Example l in whi.ch the base me~hyldimethylpolysiloxane polymer was the in w~ch there was present 0~5 parts of di-n-hexyl~ne same as Exampl~ l/to which was added 15 parts of the same trifunctional fluid as Example l, 35 parts by weight of the same trimethylsilyl~terminated po].ydimethylsiloxane as Example l, 185 parts of ~he same stearic acid treated calcium carbonate as i.n Example l and .2 paxts of Pluracol V-7 whlch is a polyether sag control agent sold by the .0 Wyandotte Chemicals Corporation. As in all the exam-ples, lO0 parts of the base compounds were catalyzed with various amounts o~ scaven~er cross~linking agent, conden-sation catalyst and self-bondlng additives in a sub . ll95B33 60Si-640 - 59 _ .
stantially anhydrous manner~ Preferably such mixing in _ pressure all cases was carried out in a Semco ~ /mixer in an anhydrous manner. The concentration of the ingredients mixed into the base compound as well as the physical properties obtained from their particular composition are shown in Table V below.
TA~LE V
_ A B C D
Base 100 100 100100 ~examethyldisilazane 2.0 2.0 ~.22.0 Methyltrimethoxysilane ~ 4.0 Dibutyltindiacetate 0.075 0.075 0.0750.1 Aminoethylaminopropyltri-methoxysilane 1.0 1.0 1.01 0 Pro~erties 5hore A, hardness 12 25 10 30 Tensile, psi 119 207 103153 Elongation, ~ 650 410 640230 Application rate 9 g. /min.
20 Tack free time, minutes ~Initial) 11 12 10 19 (20 hrs.~100UC. ac-celerated) 13 13 8 18 Peel adhesion, lbs./in.
~S Cohesive Failure (Concrete~ 7/10* 8/10 28/90 56/100 *Semi-cured at interface~
33 -~
As the results of Table V indicate the composition has good low modulus, ~ood self~bondin~ proper~ies and good shelf stability. Other conclusions that can be drawn from this data is that the level of ~rimethylme~hoxysilane in the product had a very pronounced effect on the cross-link density as shown by the difference in Duromet~r measure yoing from 0 ~o 1 to 4 parts. The ~urometer goes fro~l 12 to 2S to 30. It can also be appreciated that the h.ighest peel adhesion values obtained from concrete are o~tained at ~he 4 part level of the methyltrimethoxy-sila~e~
Example 6 There was prepaxed a base compound comprising 1.00 parts of the same dimethoxymethylsiloxy-terminated dimethyl~
0.5 parts of di-n~ laminP
siloxane polymer of Example 1,/35 pa.rts b~ weight of a tri-methylsiloxy-terminated polydimethylsiloxane of 100 centipoise viscosity at 25C. of Example 1, 10 parts by weight of the same txifunctional fluid as Exampl~ 1~
145 parts of the sam~ stearic acid ~reated calcium car-bonate of Example 1, and 3 parts by weight of the sametreated fumed silica as Example 1. A 100 parts of such base compound W2S cataly2ed withv arious amo~nts of scavenger, cross-linkin~ aaent, catalyst, and self-bondin~ additiv~s as shown in Table VI below. The physical properties of such examples, shelf-aging properties, that is the tack free time of such S samples, and the peel-adhesion values are shown in Table IV below.
TABLE VI
A B C
Base (above) 100 100 100 Hexamethyldisilazane 2.5 2.5 3.0 Methyltrimethoxysislane 0.5 0.25 0.5 Dibutyltindiacetate 0~075 0.075 0O075 Aminoethylaminopropyltri-methoxysilane 1.0 1.0 1.0 Pro~erti~
Shore A, hardness 16 15 20 TensiLe, psi. 231 140 194 Elongation, ~ 630 630 570 Application rate, g./min. 269 ~41 313 Tack free timer minutes 11 5 6 Peel Adhesion, lbs./in.
% Cohesive Failure (Cuxe 10 days at 50Q~ R.H./77F) (1) Anodized aluminum43/100 42/100 47/100 (2) Lexan 5/S 42/100 48/95 ~S (3) P~C Sl/l~0 ~4/100 50/100 (4) Glas~
(5) Polyacrylate 6/1 7/3 4~0 (6) Conor~te* 13/90 11/95 13/93 ~7) Andersen Terrestone *All of the concrete specimens werP semicured at the substrate interface.
~3 3 3 ~ 62 -Example 7 o~
Th~re were prepared a ~ase compound/100-parts of the same dimethox~methylsiloxy dime~hylsiloxan~ poly~er containin~ 0.5 parts of di-N-he~ylamune of Example 1,~5 par~s of the same trimethylsiloxy dimethylpolysiloxane of Example ]., 10 parts of t.he same tri-functi.onal fluid of Example 1, 140 parts of the sarne stearic acid tre2ted calciulu carbonate of Example 1, 3 part~ of the same txeated umed silica of Ex~mple 1, and .2 parts of polyether sold under the name of Pluracol V-7 by the Wyandotte Chemieals Corp-oration. To 100 parts of such compound there was added various amounts of scavenger, cross linki.ng agent, condensation catalyst and self-bonding additive. The physical properties as well as th~ concentration of ingredients and the peel adhesion results are shown in Table VII ~elow~
TABL~ VII
A B C
Base II 100 100 100 Hexamethyldisila~ane 2.5 2u5 3.0 Methyltrimethoxysilane 0.5 0.25 0O5 Dibutyltindiacetate 0.075 0.075 0.075 Aminoethyle~hylamino-propyltrimethoxysilalle 1.0 1.0 1.0 Example 7 (cont. ) Table VII (cont. ~
A B C
Properties Shore A, hardness 17 12 16 Tensile, psi. 199 1~3 1~7 Elongation, % 50~ 680 600 Application rate, g./min, 294 290 314 T~c~ free time, minutes 5 7 5 Peel Adhes on, lb~,/in -~ Cohesive Pailure ~:ured fox ten days 50~ R.H.~77~F~
(1) Anodized aluminum 4~/100 47/100 Sl/100 (2) Lexan 5/0 10/22 3/1 (3) PVC 51/100 47/100 51/lQ0 (4) Glass 4~93 42/93 50/95 (5) Polyacryla~e 4/0 5/0 3/0 (6) Concrete 15/93 15/97 12/95
(7) Andersen Terrastone45/100 41/100 47/130 PVC
Andexsen Terxastone PVC is thin lavers of PVC which ha~ been extruded over wood f~r use as window framPs.
The data above indicates ~he compositions had good self-bonding properties to most substrates and al~ had a 1QW modulus.
Example 8 There was prepared a base compound comprising 100 parts of the methyldimethoxydime~hylpolysiloxane :~19503~ ~ ~
- . 60SI-640 ~ 64 -0.5 ~ts of di-N-he~yl ~ ne polymer of Example 1,/3S parts of a ~remethylsiloxy-terminated dimethylpolysiloxane polymer of Example 1, 10 parts of the trifunctional fluid of Example 1 t 160 parts of the stearic acid trea~ed calcium carbonate of Example 1, 3 parts of the octameth~lcyclotetra~
siloxane treated fumed sillca of ~xAmple 1; and .2 parts o~ Pluracol V-7 of Example 6. This base colnpound was cataly~ed in a ~ubstan~ially anhydrous manner in a ~pressuxe Semco ~ixer with a scavenger, cross-linking a~ent condenscttion catalyst and self-bonding additi~e, much the same way as ~he other examples. They physical data that was obtained of the samples, ~he concentration of ingredients that were utilized to catalyze the base compound as well as the peel adhesion tests are indicated in Table VIII below~
_ABLE VIII
A s C
Parts Base . 100 100 100 Hexame~hyldisilazane 2.5 2.5 2.5 ~ethyltrime~hoxysilane 0.25 0.70 0.70 Dibutyltindiacetat~ 0.075 0O025 0.075 Aminoethylaminopropyltrim~thoxy silane 1.5 1.0 1.0 LD V~ At ~
A . B C' Parts Base 100 lC0 100 Hexamethyldisilazane 2.5 2.5 2~5 Methyltrimethoxysilane Q.25 0.70 0~70 Dibutyltindiacetate 0~0750.0~5 0.075 ~minoethylaminopropyltrimethoxy silane 1.5 1.0 1.0 ~
~hore A, hardness 10 13. 24 Tensile~ psi 109 172 31B
Elongation, % 535 470 360 Application rate, g./min. - -lS Tack free time~ minute~ 22 27 11 Peel Adhesion, lbs./in.
% Cohesive Failure (CurPd for 10 days 50~ RoHo/77~F~
(1) Al~lad Al~minum 12/5031/80 40/80 (~) Lexan 15/10041/g844/100 ~3) PVC 14/10042/8046~.00 (4) Glass 14/4542~75 47/80 (5) Polyacrylate 21/93~2/35 4/0 (6) Concrete 11/80*9/3 1~/3 2i; *Semi-cured sealant observed at substrate interf~ce.
E~ E~ 9 -There were prepared a base compound comprising 100 parts of the same methyldime~hoxypvlysiloxane po.l~m~r 0.5 parts of di~N-hexylamine as in ~xample 1 of Example 1,~10 par~s of the same tri.runctional fluld of x~mple 1, 35 parts of ~he same trime~hyl~ilyl-teIminated æolydime~hylsiloxane of ~xamDlc 1, 220 par~s of stearic acid treated calcium car~onate Hydrocarb . ...
(cont.~
95 T of Example 1 t and 3 parts of the treated fumed silica of Example 1. To this base compound, there was added 2.5 parts of hexamethyldisilazane, .5 parts of methyltrimethoxysila~e, 1.0 parts of amino ethyl aminopxopyl trimethoxysilane and O07 par~s of dibutyl-tindiacetate~ Such mixture of the base compound was p~^epared and catalyzed in sub~tantially anhydrous state in a c~ntmucus ~r-P1eiderer ~in ~ ew ex~ er. The physical da~a results of various samples of such compositions is indica~ed in Table IX below.
Table IX below also includes ~he peel adhesion re-sults of the samples. The results indicated that most samples had good self-bonding pro~erties to a number of subs~rates, were stable and had the low modulus that is desired in the present inven~ion.
, , . . .
~5~33 TABLE IX
Sample No. _ 24 44 Application rate, g./min. 258 234 210 Flow, inches 0.15 0.20 0.15 Speci~lc Gravity 1.52 1.52 1.53 Tack free time, minu-tes 30 30 30 Shore A, hardness 16 16 16 Tensile, psi. 187 184 194 Elongation, % 555 565 540 10 Adhesion, lbs./in. Samples Samples Samples (Peel) 5, 6, 7 24,25,26 44,45,46 Concrece 17/0 10/0 8/0 Glass 60/100 55/90 55/80 PVC (Rigid) 57/100 52/100 54/100 Lexan 52/100 48/100 51/100 Marviplate* 58/100 53/100 58/100 *A rigid PVC from Australia Zincalume 35/30 Not tested 31/100 Anodized aluminum55/100 55/100 52/100 Polyacrylate 40/30 38/30 37/30 - 72 hrs./100C Accelera-ted Age (Samples 24, 25, 26) cals (Sample 25) (Shore A, T n_ le_and Elongat _n) **Samples 24, 25, 26 Tack Free Time (minutes)** 20, 20, 20 Shore A 27 Tensile, psi. 300 Elongation, ~ 450 **Numbered samples taken during trial run on Werner Pfeiderer mixer.
~1 ~ .
5~33~
6~Si-640;, There was prepared a base composition havin~ 100 parts o a dimethoxy methylsiloxy termina~ed polydimethyl-siloxane polymer having a viscosity of 150 t 000 centipoise at 25~C., 0.5 parts of di-n-hexylamine, 180 parts of stearic acid treated calcium carbonate; 35 parts of trimethylsiloxy terminated polydimethylsiloxane 1uid having a viscosi y of 100 centipoise at 25C; 10 p,arts of the same high trifunc~ional fluid of the other Examples; and 5.68 p~rts of Thixcin ~ (hydrogenated castor oil). To 100 parts of the base composition there was added under substantially anhydrous conditions ~.5 parts of hexamethyldisilazane, 0.5 parts of methyltri methoxysilane~ loO parts o aminoethylaminopropyltri-methoxy silane and 0O05 parts of dibutyltindiacetate.
The physical property resul~s are in Table X b~low.
. .. ... .. .. . .
. __ ._ .. _ . ,. .. .... .. . ... _ ,... . .
TA~L~ X
Tack-Free Time, minutes 25 ~low, inches O.Q8 ~pplication rate, g~/min.164 Shore A Durometer 22 Elongation, ~ 435 Tensile, psi 248 50~ Modulus, psi 51 75~ ~lodulus, psi 62 100% Modulus, psi 75 Peel Adhesion tlO-day cure) lbs./in. ~ ~ Cohesive Failure (1) Anodized Aluminum47/100 ~2~ Lexan (polycarbonate)46/100 (3) Rigid PVC (Folyv~yl chloride) 44/100 (4) Glass 46~1.00 .... .... ~ ... .. ........ --_ .. .. .... ............ ..... ... .... . . .. .. . .. .. .. .. .. .... . . .. . . . .. ..
, _ __ ,. ..... . .. ....... ... .. . .. ..... .. .
~5~33 The addi-tives of the present case are preferably used with the RTV compositi.ons of the aforementioned Dziark U.S. Patent 4,417,042.
In one instance, Dziark discloses certain preferred silane compounds as scavengers for the RTV systems of White et al, Canadian Application Serial No.
404,949, filed June 11, 1982. The preferred systems of the aforemen-tioned Dziark U.S. Patent 4,417,042 comprise firs-t forming a polyalkoxy diorganopolysiloxane polymer and then having a scaverlging compound separate from the cross-linking agent which compound is a silazane or pol~mer, or certain amine polymeric compounds. It should be noted that -the scavengers of Dziark aforementioned U.S. Patent 4~417,042 are separate compounds and in addition to the cross-linking agent. The ~TV systems as opposed to the scavengers of Dziark aforementioned U.S. Patent 4,417,0A2 are disclosed in the White et al, aforementioned Canadian Application Serial No~ 404,949, in addition to other al]~oxy-functiona] ~TV systems. A short synopsis of the Dziark aforementioned U.S. Patent 4,417,042 system is disclosed below. For more i.nformation as to such scavengers and RTV systems one is re:Eerred to the disclosure of Dziark a:~oremerltioned U.S. Patent 4,417~042. In accordance with D~iark aforementioned U.S. Patent 4,417,042, the present Additives can be utilized with a .~table, one-pack substantially anhydrous and substantially acid~free, room temperature vulcanizable organopolysiloxane composition s-table under ambient conditions in -the substantial absence of mois-33 - -:
~;
ture over an extended period of time and convertible to a tack-free elastomer comprisin~: (1) an or~anopoly-siloxane wherein the silicon ato~ a~ each ?olymer chain end is ~erminated with at leas~ 2 alkoxy r~dicals; (23 an effective amount of a condensation c~alyst; (3) a stabilizing amount of silane scaven~er for hyllro:~y func-t:ional ~roups whic:h is a silicon~nitro~ r) compound selec~ed from the class consisting of (P~) a silicon-nitroqen compound having the f ormula R "
IY) (R3" ) 2Si N Si (R"3 ) 2Y
where Y i5 selected from R"' and R~N~ and (B) a silicon nitrogen polymer comprisinq (i) from 3 to 100 mole percent chemically com-bined structural uni~s selected rrom ~he class consisting of units havin~ the formula R'l' R"' P~" R"
l / l ()2 1 ~ ( 32 I t ( R ) 3 ~,. R"' R"' ~RI' R"' ~R" R'~
SiN , ~ SiW - , -SiN -R ~5~
33 -~
- 72 - .
. .
and (i~ from 0 t~ 97 mole percent chemically com~
bined structural units represented by t~e formula ~R"'~ SiO4 c and mixtures thereof ~here the silicon atoms of said silicon-nitrogen polymer ar~ joined to e~ch other by a member selected from ~n Si~Si linkage and a SiN~nSi linkage, the free valanccs o~ s~id silicon atoms other than those joined to oxygen to form a siloxy unit an~ nitro~en to form a silazy unit are joined to a member selected from an ~" radical and (R")2~1 radical, an~ where the ratio of the sum of said ~"' radicals an~l said (R")2N radicals to the silicon ato~s c>f said silicon-rlitrogen polymer has a val~e of 1.5 to 3, inclusive, and R" is a member selected from the class consisting of hydrogen and monovalent h~drocarbon ra~icals, and f].uGroalkyl radicals, R~ i5 a member selected from hydrogen, monovalen~
hydrocarbon radicals and fluoroalkyl rad.icals, and c is a whole number e~ual to 0 t~ 3, inclusive, and (iii) optionally an effective amount of a curing accelerator selec~ed rom the ~rou~ oon sisting of substituted guanidines, amines and mixtures thereo.
There is pre~ent from 0.5 to 10 par-ts by weight of the silicone scavenger per 100 parts by weight of the organopolysiloxane.
The silazane polymers can include cyclic silazanes of chemically combined R"l~yR"
_ SiN -R"' units where R", R"' are as previously defined to provide for a ratio of 1.5 to 3.0 of the sum of the R"' and (R")2N radicals per silicon atom in said silazane polymer.
The silazane polymer can comprise linear polymers having at least one unit selected from the class consisting of JR
(R"2N)(R"')2 SiN -uni-ts, and R"
(R"')2 SiN -un:its where R" and R"~ are as defined to provide for a .ratio o~ 1.5 to 3.0 of the sum of the R"' and (R")~N
radi.cals pe.r silicon a-tom in said silazane polymer.
I~'uxther the silazane polymers can comprise linear pol.ymers consisting essentially of R"' R"
i D
SiN
R"' ;~`
.~ 3~ ~
60Si-640 - 74 - ~
units were R" and R"' are as defined to provi~e for a ratio of 1.5 to 3.0 of the 59lm of the p~ Ql~ and (R~3~N
radicals per silicon atom in said silazane ~olymer.
The silaza~e Dolymers can comprise polymers having at least one unit selected from the class consisting of ~ "' F~"
(R")2 ~ Si~ -1.0 units and ~ "
(R ~3 SiN
units where R" and R"~ are as previously defined to provide for a ratio of 1.5 to 3 of the sum of th~ R 9~t and (R")2N radicals per silicon atom in said silazane polymer.
In addition, the silazane polymer comprises poly-mers having a sufficient amount of units selected .rom R"' R" P."' R" R"
SiN - , - sir~ , ~s iM ~
R"
where R" and R"' are as previously defined to provide for a ratio o 1~5 to 3 of the surn of ~he ~"' and (R")2N
radicals per silicon atom in said silazan~ ?olymer.
~lso, the silazane-siloxane comp~unds are co~
polymers with u~ to 97 mole percent of (~ ~9~ ~ ~Sio4-c units with most of the units being selected from where R" and R?, and c are as previously defined to provide for a ratio of the sum of R? + (R")2N radicals per silicon atom of said silazane-siloxane copolymer of from 1.5 to 3.
The silazane-siloxane compounds can be cyclics such cyclics consisting of chemically combined (R?)2SiO
units and units where R" and R? are as previously defined.
Further, the silazane nitrogen compounds are linear and cyclic silazanes having the formula ~ 5~33 60Si-~0 y.
where R" and R"' are as previously defined where n i5 a positive whole numbPr and is prefer~bly 0 ~o 20, inclusive, and d is a whole num~er equal ~o 0 to 1, inclusive, and where d is equal to 0, n is prefer~bly equal to 3 to 7, inclusive.
The sil.azane ni~rogen compoun~ can be a ~olysiloxane having the formula Rn R"' R~" R"
l I ~
ZN - SiO - - SiN -~ n R"
where ~"; R"' and n are as defined previously and ~ is 10a number s~lected from ~" and ~ Si(R"~)3.
Preferred silicon nitrogen com~ounds axe selected f.rom hexamethyldisilazane, hexamethylcyclotrisilazane, octamethylcycLotetrasilazane or silicon nitrogen con-pollnds having the formula 15LCF3 CH2 C~l2 (C~3) 2 Si]2 a sil.icon nitrogen compound havin~ the formula LCF3 CH2 CH2 ~C~3) Si ~;33 and a silicon nitrogen compound havin~ the formula LCF3 CF~2 C~;2 (CH3) 2Si]2 3
Andexsen Terxastone PVC is thin lavers of PVC which ha~ been extruded over wood f~r use as window framPs.
The data above indicates ~he compositions had good self-bonding properties to most substrates and al~ had a 1QW modulus.
Example 8 There was prepared a base compound comprising 100 parts of the methyldimethoxydime~hylpolysiloxane :~19503~ ~ ~
- . 60SI-640 ~ 64 -0.5 ~ts of di-N-he~yl ~ ne polymer of Example 1,/3S parts of a ~remethylsiloxy-terminated dimethylpolysiloxane polymer of Example 1, 10 parts of the trifunctional fluid of Example 1 t 160 parts of the stearic acid trea~ed calcium carbonate of Example 1, 3 parts of the octameth~lcyclotetra~
siloxane treated fumed sillca of ~xAmple 1; and .2 parts o~ Pluracol V-7 of Example 6. This base colnpound was cataly~ed in a ~ubstan~ially anhydrous manner in a ~pressuxe Semco ~ixer with a scavenger, cross-linking a~ent condenscttion catalyst and self-bonding additi~e, much the same way as ~he other examples. They physical data that was obtained of the samples, ~he concentration of ingredients that were utilized to catalyze the base compound as well as the peel adhesion tests are indicated in Table VIII below~
_ABLE VIII
A s C
Parts Base . 100 100 100 Hexame~hyldisilazane 2.5 2.5 2.5 ~ethyltrime~hoxysilane 0.25 0.70 0.70 Dibutyltindiacetat~ 0.075 0O025 0.075 Aminoethylaminopropyltrim~thoxy silane 1.5 1.0 1.0 LD V~ At ~
A . B C' Parts Base 100 lC0 100 Hexamethyldisilazane 2.5 2.5 2~5 Methyltrimethoxysilane Q.25 0.70 0~70 Dibutyltindiacetate 0~0750.0~5 0.075 ~minoethylaminopropyltrimethoxy silane 1.5 1.0 1.0 ~
~hore A, hardness 10 13. 24 Tensile~ psi 109 172 31B
Elongation, % 535 470 360 Application rate, g./min. - -lS Tack free time~ minute~ 22 27 11 Peel Adhesion, lbs./in.
% Cohesive Failure (CurPd for 10 days 50~ RoHo/77~F~
(1) Al~lad Al~minum 12/5031/80 40/80 (~) Lexan 15/10041/g844/100 ~3) PVC 14/10042/8046~.00 (4) Glass 14/4542~75 47/80 (5) Polyacrylate 21/93~2/35 4/0 (6) Concrete 11/80*9/3 1~/3 2i; *Semi-cured sealant observed at substrate interf~ce.
E~ E~ 9 -There were prepared a base compound comprising 100 parts of the same methyldime~hoxypvlysiloxane po.l~m~r 0.5 parts of di~N-hexylamine as in ~xample 1 of Example 1,~10 par~s of the same tri.runctional fluld of x~mple 1, 35 parts of ~he same trime~hyl~ilyl-teIminated æolydime~hylsiloxane of ~xamDlc 1, 220 par~s of stearic acid treated calcium car~onate Hydrocarb . ...
(cont.~
95 T of Example 1 t and 3 parts of the treated fumed silica of Example 1. To this base compound, there was added 2.5 parts of hexamethyldisilazane, .5 parts of methyltrimethoxysila~e, 1.0 parts of amino ethyl aminopxopyl trimethoxysilane and O07 par~s of dibutyl-tindiacetate~ Such mixture of the base compound was p~^epared and catalyzed in sub~tantially anhydrous state in a c~ntmucus ~r-P1eiderer ~in ~ ew ex~ er. The physical da~a results of various samples of such compositions is indica~ed in Table IX below.
Table IX below also includes ~he peel adhesion re-sults of the samples. The results indicated that most samples had good self-bonding pro~erties to a number of subs~rates, were stable and had the low modulus that is desired in the present inven~ion.
, , . . .
~5~33 TABLE IX
Sample No. _ 24 44 Application rate, g./min. 258 234 210 Flow, inches 0.15 0.20 0.15 Speci~lc Gravity 1.52 1.52 1.53 Tack free time, minu-tes 30 30 30 Shore A, hardness 16 16 16 Tensile, psi. 187 184 194 Elongation, % 555 565 540 10 Adhesion, lbs./in. Samples Samples Samples (Peel) 5, 6, 7 24,25,26 44,45,46 Concrece 17/0 10/0 8/0 Glass 60/100 55/90 55/80 PVC (Rigid) 57/100 52/100 54/100 Lexan 52/100 48/100 51/100 Marviplate* 58/100 53/100 58/100 *A rigid PVC from Australia Zincalume 35/30 Not tested 31/100 Anodized aluminum55/100 55/100 52/100 Polyacrylate 40/30 38/30 37/30 - 72 hrs./100C Accelera-ted Age (Samples 24, 25, 26) cals (Sample 25) (Shore A, T n_ le_and Elongat _n) **Samples 24, 25, 26 Tack Free Time (minutes)** 20, 20, 20 Shore A 27 Tensile, psi. 300 Elongation, ~ 450 **Numbered samples taken during trial run on Werner Pfeiderer mixer.
~1 ~ .
5~33~
6~Si-640;, There was prepared a base composition havin~ 100 parts o a dimethoxy methylsiloxy termina~ed polydimethyl-siloxane polymer having a viscosity of 150 t 000 centipoise at 25~C., 0.5 parts of di-n-hexylamine, 180 parts of stearic acid treated calcium carbonate; 35 parts of trimethylsiloxy terminated polydimethylsiloxane 1uid having a viscosi y of 100 centipoise at 25C; 10 p,arts of the same high trifunc~ional fluid of the other Examples; and 5.68 p~rts of Thixcin ~ (hydrogenated castor oil). To 100 parts of the base composition there was added under substantially anhydrous conditions ~.5 parts of hexamethyldisilazane, 0.5 parts of methyltri methoxysilane~ loO parts o aminoethylaminopropyltri-methoxy silane and 0O05 parts of dibutyltindiacetate.
The physical property resul~s are in Table X b~low.
. .. ... .. .. . .
. __ ._ .. _ . ,. .. .... .. . ... _ ,... . .
TA~L~ X
Tack-Free Time, minutes 25 ~low, inches O.Q8 ~pplication rate, g~/min.164 Shore A Durometer 22 Elongation, ~ 435 Tensile, psi 248 50~ Modulus, psi 51 75~ ~lodulus, psi 62 100% Modulus, psi 75 Peel Adhesion tlO-day cure) lbs./in. ~ ~ Cohesive Failure (1) Anodized Aluminum47/100 ~2~ Lexan (polycarbonate)46/100 (3) Rigid PVC (Folyv~yl chloride) 44/100 (4) Glass 46~1.00 .... .... ~ ... .. ........ --_ .. .. .... ............ ..... ... .... . . .. .. . .. .. .. .. .. .... . . .. . . . .. ..
, _ __ ,. ..... . .. ....... ... .. . .. ..... .. .
~5~33 The addi-tives of the present case are preferably used with the RTV compositi.ons of the aforementioned Dziark U.S. Patent 4,417,042.
In one instance, Dziark discloses certain preferred silane compounds as scavengers for the RTV systems of White et al, Canadian Application Serial No.
404,949, filed June 11, 1982. The preferred systems of the aforemen-tioned Dziark U.S. Patent 4,417,042 comprise firs-t forming a polyalkoxy diorganopolysiloxane polymer and then having a scaverlging compound separate from the cross-linking agent which compound is a silazane or pol~mer, or certain amine polymeric compounds. It should be noted that -the scavengers of Dziark aforementioned U.S. Patent 4~417,042 are separate compounds and in addition to the cross-linking agent. The ~TV systems as opposed to the scavengers of Dziark aforementioned U.S. Patent 4,417,0A2 are disclosed in the White et al, aforementioned Canadian Application Serial No~ 404,949, in addition to other al]~oxy-functiona] ~TV systems. A short synopsis of the Dziark aforementioned U.S. Patent 4,417,042 system is disclosed below. For more i.nformation as to such scavengers and RTV systems one is re:Eerred to the disclosure of Dziark a:~oremerltioned U.S. Patent 4,417~042. In accordance with D~iark aforementioned U.S. Patent 4,417,042, the present Additives can be utilized with a .~table, one-pack substantially anhydrous and substantially acid~free, room temperature vulcanizable organopolysiloxane composition s-table under ambient conditions in -the substantial absence of mois-33 - -:
~;
ture over an extended period of time and convertible to a tack-free elastomer comprisin~: (1) an or~anopoly-siloxane wherein the silicon ato~ a~ each ?olymer chain end is ~erminated with at leas~ 2 alkoxy r~dicals; (23 an effective amount of a condensation c~alyst; (3) a stabilizing amount of silane scaven~er for hyllro:~y func-t:ional ~roups whic:h is a silicon~nitro~ r) compound selec~ed from the class consisting of (P~) a silicon-nitroqen compound having the f ormula R "
IY) (R3" ) 2Si N Si (R"3 ) 2Y
where Y i5 selected from R"' and R~N~ and (B) a silicon nitrogen polymer comprisinq (i) from 3 to 100 mole percent chemically com-bined structural uni~s selected rrom ~he class consisting of units havin~ the formula R'l' R"' P~" R"
l / l ()2 1 ~ ( 32 I t ( R ) 3 ~,. R"' R"' ~RI' R"' ~R" R'~
SiN , ~ SiW - , -SiN -R ~5~
33 -~
- 72 - .
. .
and (i~ from 0 t~ 97 mole percent chemically com~
bined structural units represented by t~e formula ~R"'~ SiO4 c and mixtures thereof ~here the silicon atoms of said silicon-nitrogen polymer ar~ joined to e~ch other by a member selected from ~n Si~Si linkage and a SiN~nSi linkage, the free valanccs o~ s~id silicon atoms other than those joined to oxygen to form a siloxy unit an~ nitro~en to form a silazy unit are joined to a member selected from an ~" radical and (R")2~1 radical, an~ where the ratio of the sum of said ~"' radicals an~l said (R")2N radicals to the silicon ato~s c>f said silicon-rlitrogen polymer has a val~e of 1.5 to 3, inclusive, and R" is a member selected from the class consisting of hydrogen and monovalent h~drocarbon ra~icals, and f].uGroalkyl radicals, R~ i5 a member selected from hydrogen, monovalen~
hydrocarbon radicals and fluoroalkyl rad.icals, and c is a whole number e~ual to 0 t~ 3, inclusive, and (iii) optionally an effective amount of a curing accelerator selec~ed rom the ~rou~ oon sisting of substituted guanidines, amines and mixtures thereo.
There is pre~ent from 0.5 to 10 par-ts by weight of the silicone scavenger per 100 parts by weight of the organopolysiloxane.
The silazane polymers can include cyclic silazanes of chemically combined R"l~yR"
_ SiN -R"' units where R", R"' are as previously defined to provide for a ratio of 1.5 to 3.0 of the sum of the R"' and (R")2N radicals per silicon atom in said silazane polymer.
The silazane polymer can comprise linear polymers having at least one unit selected from the class consisting of JR
(R"2N)(R"')2 SiN -uni-ts, and R"
(R"')2 SiN -un:its where R" and R"~ are as defined to provide for a .ratio o~ 1.5 to 3.0 of the sum of the R"' and (R")~N
radi.cals pe.r silicon a-tom in said silazane polymer.
I~'uxther the silazane polymers can comprise linear pol.ymers consisting essentially of R"' R"
i D
SiN
R"' ;~`
.~ 3~ ~
60Si-640 - 74 - ~
units were R" and R"' are as defined to provi~e for a ratio of 1.5 to 3.0 of the 59lm of the p~ Ql~ and (R~3~N
radicals per silicon atom in said silazane ~olymer.
The silaza~e Dolymers can comprise polymers having at least one unit selected from the class consisting of ~ "' F~"
(R")2 ~ Si~ -1.0 units and ~ "
(R ~3 SiN
units where R" and R"~ are as previously defined to provide for a ratio of 1.5 to 3 of the sum of th~ R 9~t and (R")2N radicals per silicon atom in said silazane polymer.
In addition, the silazane polymer comprises poly-mers having a sufficient amount of units selected .rom R"' R" P."' R" R"
SiN - , - sir~ , ~s iM ~
R"
where R" and R"' are as previously defined to provide for a ratio o 1~5 to 3 of the surn of ~he ~"' and (R")2N
radicals per silicon atom in said silazan~ ?olymer.
~lso, the silazane-siloxane comp~unds are co~
polymers with u~ to 97 mole percent of (~ ~9~ ~ ~Sio4-c units with most of the units being selected from where R" and R?, and c are as previously defined to provide for a ratio of the sum of R? + (R")2N radicals per silicon atom of said silazane-siloxane copolymer of from 1.5 to 3.
The silazane-siloxane compounds can be cyclics such cyclics consisting of chemically combined (R?)2SiO
units and units where R" and R? are as previously defined.
Further, the silazane nitrogen compounds are linear and cyclic silazanes having the formula ~ 5~33 60Si-~0 y.
where R" and R"' are as previously defined where n i5 a positive whole numbPr and is prefer~bly 0 ~o 20, inclusive, and d is a whole num~er equal ~o 0 to 1, inclusive, and where d is equal to 0, n is prefer~bly equal to 3 to 7, inclusive.
The sil.azane ni~rogen compoun~ can be a ~olysiloxane having the formula Rn R"' R~" R"
l I ~
ZN - SiO - - SiN -~ n R"
where ~"; R"' and n are as defined previously and ~ is 10a number s~lected from ~" and ~ Si(R"~)3.
Preferred silicon nitrogen com~ounds axe selected f.rom hexamethyldisilazane, hexamethylcyclotrisilazane, octamethylcycLotetrasilazane or silicon nitrogen con-pollnds having the formula 15LCF3 CH2 C~l2 (C~3) 2 Si]2 a sil.icon nitrogen compound havin~ the formula LCF3 CH2 CH2 ~C~3) Si ~;33 and a silicon nitrogen compound havin~ the formula LCF3 CF~2 C~;2 (CH3) 2Si]2 3
Claims (156)
1. A stable, one-package, substantially anhydrous and substantially acid-free, room temperature vulcanizable organopolysiloxane composition stable under ambient conditions in the substantial absence of moisture over an extended period of time and convertible to a tack-free elastomer comprising: (1) an organopolysiloxane wherein the silicon atom at each polymer chain end is terminated with at least 2 alkoxy radicals; (2) an effective amount of a condensation catalyst; (3) a stabilizing amount of silane scavenger for hydroxy functional groups having the formula where R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato, and ureido radicals, and c is a whole number equal to 0 to 3, inclusive, f is an integer equal to 1 to 4 inclusive, and the sum od c + f is equal to 1 to 4 inclusive; and (4) where X is enoxy or amido, an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof; and (5) from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid containing a high degree of trifunctionality or mixtures of tri- and tetrafunctionality and comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicone-bonded hydroxyl groups.
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicone-bonded hydroxyl groups.
2. The composition of claim 1 wherein said organopolysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
3. The composition of claim 2 wherein there is further present from 5 to 60 parts by weight of a second plasticizer per 100 parts of said organopolysiloxane, said second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
4. The composition of claim 3 wherein said second plasticizer polymer has the formula where R20 is a monovalent hydrocarbon radical and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
5. The composition of claim 4 wherein R20 is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
6. The composition of claim 4 wherein there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
7. The composition of claim 6 wherein the extending filler is calcium carbonate.
8. The composition of claim 7 wherein the calcium carbonate is treated with stearic acid.
9. The composition of claim 6 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organopolysiloxane of a reinforcing filler.
10. The composition of claim 9 wherein the reinforcing filler is a sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
11. The composition of claim 10 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms, and radicals, where R is an alkyl containing from 1 to 11 carbon atoms, Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, tri-methylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of from 2 to 4; n is an integer equal to from 4 to 2000;
y has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
y has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
12. The composition of claim 6 wherein there is present from 0.2 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a sag control agent which is hydrogenated castor oil.
13. The composition of claim 2 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
14. The composition of claim 1 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30 and R31 are selected from C(1-8) monovalent hydrocarbon radicals, R38 and R40 are selected from the group consisting of hydrogen and C(1-6) monovalent hydrocarbon radicals, R34 is selected from hydrogen and C(1-3) alkyl radicals and R33 is selected from hydrogen and methyl, R32 and R36 are selected from C(1-12) divalent hydrocarbon radicals and p is a whole number that varies from 0 to 3.
15. The composition of claim 14 wherein the adhesion promoter has the formula
16. The composition of claim 1 wherein the silane has the formula where R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkyl-ester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato and ureido radicals; and a is an integer equal to 1 to 2 inclusive, b is a whole number equal to 0 to 1 inclusive, and the sum of b + a is equal to 1 to 2 inclusive and the silane is both the silane scavenger for hydroxy functional groups and a polyalkoxysilane cross-linking agent for terminating the silicon atom at each organopolysiloxane chain end with at least two alkoxy radicals.
17. A stable, one-package, substantially anhydrous and substantially acid-free, room temperature vulcanizable organopolysiloxane composition stable under ambient conditions in the substantial absence of moisture over an extended period of time and convertible to a tack-free elastomer comprising: (1) an organopolysiloxane wherein the silicon atom at each polymer chain end is terminated with at least 2 alkoxy radicals; (2) an effective amount of a condensation catalyst; (3) a stabilizing amount of silane scavenger for hydroxy functional groups having the formula where R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkyl ester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato and ureido radicals, and c is a whole number equal to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c + f is equal to 1 to 4 inclusive; (4) an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof; and (5) from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunctionality or mixtures of tri- and tetrafunctionality comprising (i) from 5 to 60 mole percent of monoalkylsiloxany units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
18. The composition of claim 17 wherein said organopolysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
19. The composition of claim 18 wherein there is further present from 5 to 60 parts by weight of a second plasticizer per 100 parts of said organopolysiloxane, said second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
20. The composition of claim 19 wherein said second plasticizer polymer has the formula where R20 is a monovalent hydrocarbon radical and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
21. The composition of claim 20 wherein R20 is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
22. The composition of claim 20 wherein there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
23. The composition* of claim 22 wherein the extending filler is calcium carbonate.
24. The composition of claim 23 wherein the calcium carbonate is treated with stearic acid.
25. The composition of claim 22 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organopolysiloxane of a reinforcing filler.
26. The composition of claim 25 wherein the reinforcing filler is a first sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
27. The composition of claim 24 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas A - O - (CxH2xO)n - B
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
where R is alkyl containing from 1 to 11 carbon atoms;
Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000; y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
where R is alkyl containing from 1 to 11 carbon atoms;
Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000; y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
28. The composition of claim 22 wherein there is present from 0.2 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a sag control agent which is hydrogenated castor oil.
29. The composition of claim 25 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
30. The composition of claim 17 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30 and R31 are selected from C(1-8) monovalent hydrocarbon radicals, R32 and R36 are selected from C(1-12) divalent hydrocarbon radicals, R38 and R40 are selected from the class consisting of hydrogen and C(1-6) monovalent hydrocarbon radicals, R34 is selected from hydrogen and C(1-3) alkyl radicals, R33 is selected from hydrogen and methyl, and p is a whole number that varies from 0 to 3.
31. The composition of claim 30 wherein the adhesion promoter has the formula
32. A one-package, room temperature vulcanizable polyalkoxy-terminated organopolysiloxane composition in accordance with claim 1, where the polyalkoxy-terminated organopolysiloxane has the formula where R is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato and ureido radicals, and b is a whole number equal to 0 or 1, e is a whole number equal to 0 to 1 inclusive and the sum of b + e is equal to 0 or 1 inclusive, and n is an integer having a value of from about 50 to about 2500 inclusive.
33. A room temperature vulcanizable composition in accordance with claim 1 having an effective amount of a cross-linking silane of the formula where R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkyl-ester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, and b is a whole number equal to 0 or 1.
34. A room temperature vulcanizable composition in accordance with claim 1, where the silane scavenger is methyldimethoxy(N-methylacetamido)silane.
35. A room temperature vulcanizable composition in accordance with claim 1, which contains a tin compound as the condensation catalyst.
36. A room temperature vulcanizable composition in accordance with claim 35 where R, R1 and R2 are methyl and which has a tin compound as a condensation catalyst.
37. A room temperature vulcanizable composition in accordance with claim 1, containing an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof.
38. A stable, one-package, substantially anhydrous and substantially acid-free room temperature vulcanizable composition in accordance with claim 1 comprising, as the organopolysiloxane, a polymethoxy-terminated polydimethylsiloxane, an effective amount of a tin-containing condensation catalyst, and a stabilizing amount of an alkyldialkoxy-n-dialkylaminosilane or alkyl-dialkoxyalkylguanidylsilane as both the scavenger and cure accelerator.
39. A stable, one-package, substantially acid-free, room temperature vulcanizable composition of claim 1 comprising a polymethoxy-terminated polydimethylsiloxane, an effective amount of a tin containing condensation catalyst, an effective amount of trimethoxysilylpropyl-tetramethylguanidine curing accelerator and a stabilizing amount of a polymethoxyacetamidosilane.
40. An RTV composition in accordance with claim 38 wherein the tin-containing condensation catalyst is dibutyltindiacetate.
41. An RTV composition in accordance with claim 38 containing a polymethoxysilane cross-linking agent.
42. A stable and substantially acid-free, one-package room temperature vulcanizable polyalkoxy-terminated organopolysiloxane composition curable under ambient conditions to a tack-free elastomer over an extended period of time comprising on a weight basis, (i) 100 parts of a substantially silanol-free polyalkoxysiloxydiorganopolysiloxane of the formula (ii) 0 to 10 parts of a cross-linking polyalkoxy-silane of the formula
42. A stable and substantially acid-free, one-package room temperature vulcanizable polyalkoxy-terminated organopolysiloxane composition curable under ambient conditions to a tack-free elastomer over an extended period of time comprising on a weight basis, (i) 100 parts of a substantially silanol-free polyalkoxysiloxydiorganopolysiloxane of the formula (ii) 0 to 10 parts of a cross-linking polyalkoxy-silane of the formula
Claim 42 - Cont'd.
(iii) an effective amount of a condensation catalyst, and (iv) a stabilizing amount of a silane scavenger for hydroxy functional groups having the formula where R is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato and ureido radicals, and b is a whole number equal to 0 to 1, e is a whole number equal to 0 to 1 inclusive, and the sum of b + e is equal to 0 to 1 inclusive, and n is an integer having a value of from about 50 to about 2500 inclusive, c is a whole number equal to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c + f is equal to 4 inclusive; and (v) where X is enoxy or amido there is present 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines, and mixtures thereof, and (vi) from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunction-ality or mixtures of tri- and tetra-functionality comrprising (a) from 5 to 60 mole percent of mono-alkylsiloxy units, siloxy units or a mixture of such units;
(b) from 1 to 6 mole percent of trialkyl-siloxy units and, (c) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
(iii) an effective amount of a condensation catalyst, and (iv) a stabilizing amount of a silane scavenger for hydroxy functional groups having the formula where R is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato and ureido radicals, and b is a whole number equal to 0 to 1, e is a whole number equal to 0 to 1 inclusive, and the sum of b + e is equal to 0 to 1 inclusive, and n is an integer having a value of from about 50 to about 2500 inclusive, c is a whole number equal to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c + f is equal to 4 inclusive; and (v) where X is enoxy or amido there is present 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines, and mixtures thereof, and (vi) from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunction-ality or mixtures of tri- and tetra-functionality comrprising (a) from 5 to 60 mole percent of mono-alkylsiloxy units, siloxy units or a mixture of such units;
(b) from 1 to 6 mole percent of trialkyl-siloxy units and, (c) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
43. The composition of claim 42 wherein said organopolysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
44. The composition of claim 43 wherein there is further present from 5 to 60 parts by weight of a second plasticizer per 100 parts of said organopolysiloxane, said second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
45. The composition of claim 44 wherein said second plasticizer polymer has the formula where R20 is a monovalent hydrocarbon radical and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
46. The composition of claim 45 wherein R20 is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
47. The composition of claim 45 wherein there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
48. The composition of claim 47 wherein the extending filler is calcium carbonate.
49. The composition of claim 48 wherein the calcium carbonate is treated with stearic acid.
50. The composition of claim 47 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organopolysiloxane of a reinforcing filler.
51. The composition of claim 49 wherein the reinforcing filler is a sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
52. The composition of claim 49 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas consisting of and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
radicals, where R is an alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radial containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethylol-propane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000; y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
radicals, where R is an alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radial containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethylol-propane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000; y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
53. The composition of claim 47 wherein there is present agent which is present from 0.2 to 2.0 parts by weight per 100 parts by weight of said organopoly-siloxane of a sag control agent which is a hydrogenated castor oil.
54. The composition of claim 43 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
55. The composition of claim 42 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30 and R31 are selected from C(1-8) monovalent hydrocarbon radicals, R32 and R36 are selected from C(1-12) divalent hydrocarbon radicals, R38 and R40 are selected from the class consisting of hydrogen and C(1-6) monovalent hydrocarbon radicals, R34 is selected from hydrogen and C(1-3) alkylradicals and R33 is selected from hydrogen and methyl, and p is a whole number that varies from 0 to 3.
56. The composition of claim 55 wherein the adhesion promoter has the formula
57. A room temperature vulcanizable polyalkoxy-terminated organopolysiloxane composition in accordance with claim 42 containing an effective amount of a curing accelerator selected from the group consisting of sub-stituted guanidines, amines and mixtures thereof.
58. A one-package, room-temperature vulcanizable composition in accordance with claim 42 where R, R1 and R2 are methyl.
59. A one-package room temperature vulcanizable composition in accordance with claim 42 where the conden-sation catalyst is a tin compound.
60. A stable and substantially acid-free, one-package, room temperature vulcanizable composition of claim 42 comprising a polymethoxy-terminated polydimethyl-siloxane, a polymethoxysilane, an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, an effective amount of a tin compound condensation catalyst, and a stabilizing amount of a silane scavenger for hydroxy functional groups having at least one hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioiso-cyanato and ureido radicals.
61. A one-package room temperature vulcanizable composition in accordance with claim 60 where the poly-methoxysilane is methyltrimethoxysilane.
62. A one-package room temperature vulcanizable composition in accordance with claim 60, where the substituted guanidine is butyltetramethylguanidine.
63. A one-package room temperature vulcanizable composition in accordance with claim 60 where the organic amine is a dialkylamine.
64. A substantially acid-free room temperature vulcanizable composition of claim 1 comprising methyl-dimethoxysiloxy terminated polydimethylsiloxane, a reinforcing amount of octamethylcyclotetrasiloxane treated silica filler, an effective amount of dibutyltindiacetate condensation catalyst, a cure accelerating amount of trimethoxysilylpropyltetramethylguanidine and an excess of up to 3% by weight, based on the weight of the polydimethyl-siloxane of methyldimethoxy-N-methylacetamidosilane.
65. A one-package, stable room temperature vulcanizable composition in accordance with claim 1, comprising methyldimethoxysiloxy terminated polydimethyl-siloxane, a reinforcing amount of octamethylcyclotetra-siloxane treated silica filler, an effective amount of dibutyltindiacetate condensation catalyst, a cure accelerating amount of trimethoxysilylpropyltetramethyl-guanidine and an excess of up to 3% by weight, based on the weight of the polydimethyl siloxane of methyldimethoxyiso-propenoxysilane.
66. A room temperature vulcanizable composition in accordance with claim 63 having up to 10 parts of methyltrimethoxysilane per 100 parts of the polydimethyl-siloxane.
67. A room temperature vulcanizable composition in accordance with claim 63 having an effective amount of di-n-hexylamine curing accelerator in place of trimethoxy-silylpropyltetramethylguanidine.
68. A method of making a one-package and substantially acid-free room temperature vulcanizable composition curable to the solid elastomeric state, which method comprises agitating under substantially anhydrous conditions at a temperature in the range of from 0°C to 180°C, a room temperature vulcanizable material selected from (i) a mixture comprising (a) 100 parts of a silanol-terminated polydiorganosiloxane consisting essentially of chemically combined units of the formula (b) a stabilizing amount of a silane scavenger for hydroxy functional groups of the formula (c) 0 to 10 parts of cross-linking silane of the formula (d) an effective amount of a condensation catalyst, and
68. A method of making a one-package and substantially acid-free room temperature vulcanizable composition curable to the solid elastomeric state, which method comprises agitating under substantially anhydrous conditions at a temperature in the range of from 0°C to 180°C, a room temperature vulcanizable material selected from (i) a mixture comprising (a) 100 parts of a silanol-terminated polydiorganosiloxane consisting essentially of chemically combined units of the formula (b) a stabilizing amount of a silane scavenger for hydroxy functional groups of the formula (c) 0 to 10 parts of cross-linking silane of the formula (d) an effective amount of a condensation catalyst, and
Claim 68 continued:
(e) where ingredient (b) is enoxy or amido functional, 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof; and (ii) a mixture comprising (a) 100 parts of a polyalkoxy-terminated organopolysiloxane of the formula (b) 0 to 10 parts of a cross-linking silane of the formula (c) an effective amount of a condensation catalyst;
(d) a stabilizing amount of a silane scavenger for hydroxy functional groups having the formula.
and (e) where ingredient (d) is enoxy or amido functional, 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, where R is selected from C(1-13) monovalent substituted and unsubstituted hydro-carbon radicals, R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, and a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioiso-cyanato and ureido radicals, and a is an integer equal to 1 or 2, b is a whole number equal to 0 or 1, and the sum of a + b is equal to 1 or 2, e is a whole number equal to 0 or 1 and the sum of b + e is equal to 0 or 1, n is an integer having a value of from about 50 to about 2500 inclusive, c is a whole number equal to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c + f equals 1 to 4 inclusive; and (f) from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid siloxane containing a high degree of trifunctionality or mixtures of tri- and tetrafunctionality comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said first plasticizer fluid containing from about 0.1 to about 2% by weight of silicon bonded hydroxyl groups.
(e) where ingredient (b) is enoxy or amido functional, 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof; and (ii) a mixture comprising (a) 100 parts of a polyalkoxy-terminated organopolysiloxane of the formula (b) 0 to 10 parts of a cross-linking silane of the formula (c) an effective amount of a condensation catalyst;
(d) a stabilizing amount of a silane scavenger for hydroxy functional groups having the formula.
and (e) where ingredient (d) is enoxy or amido functional, 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, where R is selected from C(1-13) monovalent substituted and unsubstituted hydro-carbon radicals, R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, and a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioiso-cyanato and ureido radicals, and a is an integer equal to 1 or 2, b is a whole number equal to 0 or 1, and the sum of a + b is equal to 1 or 2, e is a whole number equal to 0 or 1 and the sum of b + e is equal to 0 or 1, n is an integer having a value of from about 50 to about 2500 inclusive, c is a whole number equal to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c + f equals 1 to 4 inclusive; and (f) from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid siloxane containing a high degree of trifunctionality or mixtures of tri- and tetrafunctionality comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said first plasticizer fluid containing from about 0.1 to about 2% by weight of silicon bonded hydroxyl groups.
69. The method of claim 68 wherein said organo-polysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
70. The method of claim 69 wherein there is further present from 5 to 60 parts by weight of a second plasticizer per 100 parts of said organopolysiloxane, said second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
71. The method of claim 70 wherein said second plasticizer polymer has the formula where R20 is a monovalent hydrocarbon radical and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
72. The method of claim 71 wherein R20 is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
73. The method of claim 71 wherein there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
74. The method of claim 73 wherein the extending filler is calcium carbonate.
75. The method of claim 74 wherein the calcium carbonate is treated with stearic acid.
76. The method of claim 73 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organo polysiloxane of a reinforcing filler.
77. The method of claim 76 wherein the rein-forcing filler is a first sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
78. The method of claim 77 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas A - O - (CxH2xO)n - B
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 *
to 12 carbon atoms, cyaloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000;
y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 *
to 12 carbon atoms, cyaloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000;
y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
79. The method of claim 73 wherein there is present from 0.2 to 2.0 parts by weight per 100 parts by eight of said organopolysiloxane of a sag control agent which is a hydrogenated castor oil.
80. The method of claim 76 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
81. The method of claim 68 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30 and R31 are selected from C(1-8) monovalent hydrocarbon radicals, R32 and R36 are selected from C(1-12) divalent hydrocarbon radicals, R38 and R40 are selected from the group consisting of hydrogen and C(1-6) monovalent hydrocarbon radicals, R34 is selected from hydrogen and C(1-3) alkyl radicals and R33 is selected from hydrogen and methyl, and p is a whole number that varies from 0 to 3.
82. The method of claim 81 wherein the adhesion promoter has the formula
83. A method in accordance with claim 68 where R, R1 and R2 are methyl.
84. A method in accordance with claim 68 where the curing accelerator is selected from the group consist-ing of silylated guanidine and alkyl guanidine.
85. A method in accordance with claim 68 where the scavenging silane is a polymethoxyacetamidosilane.
86. A method in accordance with claim 68 where the cross-linking silane is methyltrimethoxysilane.
87. A method in accordance with claim 68 where the condensation catalyst is a tin compound.
88. A method in accordance with claim 87 where the silane scavenger is methyldimethoxy(n-methylacetamido) silane.
89. A mixture comprising (a) 100 parts of a silanol-terminated organo-polysiloxane consisting essentially of chemically combined units of the formula (b) a stabilizing amount of a silane scavenger for hydroxy functional groups of the formula (c) 0 to 10 parts of cross-linking silane of the formula
89. A mixture comprising (a) 100 parts of a silanol-terminated organo-polysiloxane consisting essentially of chemically combined units of the formula (b) a stabilizing amount of a silane scavenger for hydroxy functional groups of the formula (c) 0 to 10 parts of cross-linking silane of the formula
Claim 89 continued:
(d) an effective amount of a condensation catalyst, and (e) wherein ingredient (b) is enoxy or amido functional, 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, where R is selected from C(1-13) monovalent substituted and unsubstituted hydrocarbon radicals, R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioiso-cyanato and ureido radicals, and a is an integer equal to 1 or 2, b is a whole number equal to 0 or 1, and the sum of a + b is equal to 1 or 2; and from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunctionality or mixtures of tri- and tetra-functaionality comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to 2%
by weight of silicon-bonded hydroxyl groups.
(d) an effective amount of a condensation catalyst, and (e) wherein ingredient (b) is enoxy or amido functional, 0.1 to 5 parts of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, where R is selected from C(1-13) monovalent substituted and unsubstituted hydrocarbon radicals, R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioiso-cyanato and ureido radicals, and a is an integer equal to 1 or 2, b is a whole number equal to 0 or 1, and the sum of a + b is equal to 1 or 2; and from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunctionality or mixtures of tri- and tetra-functaionality comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to 2%
by weight of silicon-bonded hydroxyl groups.
90. The mixture of claim 89 wherein said organopolysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
91. The mixture of claim 90 wherein there is further present from 5 to 60 parts by weight of a second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
92. The mixture of claim 91 wherein said second plasticizer polymer has the formula where R20 is a monovalent hydrocarbon radical and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
93. The mixture of claim 92 wherein R20 is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
94. The mixture of claim 92 wherein there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
95. The mixture of claim 94 wherein the extending filler is calcium carbonate.
96. The mixture of claim 95 wherein the calcium carbonate is treated with stearic acid.
97. The mixture of claim 97 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organopolysiloxane of a reinforcing filler.
98. The mixture of claim 97 wherein the reinforcing filler is a sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
99. The mixture of claim 98 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas A - O - (CxH2xO)n - B
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cyclicalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, tri-methylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000;
y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to 200,000.
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cyclicalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, tri-methylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000;
y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to 200,000.
100. The mixture of claim 94 wherein there is present from 0.2 to 2 parts by weight per 100 parts by weight of said organopolysiloxane of a sag control agent which is a hydrogenated castor oil.
101. The mixture of claim 97 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
102. The mixture of claim 89 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30, R31 are selected from C(1-8) monovalent hydro-carbon radicals, R32, R36 are selected from C(1-12) divalent hydrocarbon radicals, R38 and R40 are selected from the class consisting of hydrogen and C(1-6) mono-valent hydrocarbon radicals, R34 is selected from hydrogen and C(1-3) alkyl radicals and R33 is selected from hydrogen and methyl, and p is a whole number that varies from 0 to 3.
103. The mixture of claim 102 wherein the adhesion promoter has the formula
104. In the method of making a substantially acid-free room temperature vulcanizable organopolysiloxane composition under substantially anhydrous conditions utilizing an effective amount of a condensation catalyst with a silanol-terminated organopolysiloxane and a polyalkoxysilane cross-linking agent, the improvement which comprises adding to the silanol-terminated organo-polysiloxane a stabilizing amount of a polyalkoxysilane which is both a scavenger for hydroxy functional groups and a cross-linking agent of the formula where R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkyl-ester, alkylketone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, ixocyanato, oximato, thioisocyanato and ureido radicals, and a is an integer equal to 1 or 2, b is an integer equal to 0 to 1, and the sum of a + b is equal to 1 or 2, and thereafter adding an effective amount of a condensation catalyst, whereby improved stability is achieved in the resulting room temperature vulcanizable organopolysiloxane composition, and where X is enoxy or amido, adding before or with the scavenger an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof and from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunctionality or mixtures of tri- and tetra-functionality and comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
105. The method of claim 104 wherein said organopolysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
106. The method of claim 105 wherein there is further present from 5 to 60 parts by weight of a second plasticizer per 100 parts of said organopolysiloxane, said second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
107. The method of claim 106 wherein said second plasticizer polymer has the formula R20 is a monovalent hydrocarbon radical, and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
108. The method of claim 107 wherein R20 is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
109. The method of claim 107 wherein there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
110. The method of claim 109 wherein the extending filler is calcium carbonate.
111. The method of claim 110 wherein the calcium carbonate is treated with stearic acid.
112. The method of claim 109 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organopolysiloxane of a reinforcing filler.
113. The method of claim 111 wherein the reinforcing filler is a first sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
114. The method of claim 113 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas A - O - (CxH2xO)n - B
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, tri-methylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups, x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000;
y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms;
radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, tri-methylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups, x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000;
y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
115. The method of claim 109 wherein there is present from 0.2 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a sag control agent which is a hydrogenated caster oil.
116. The method of claim 112 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
117. The method of claim 104 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30, R31 are selected from C(1-8) monovalent hydro-carbon radicals, R32, R36 are selected from C(1-12) divalent hydrocarbon radicals, R38 and R40 are selected from the group consisting of hydrogen and C(1-6) monovalent hydrocarbon radicals, R34 is selected from hydrogen and C(1-3) alkyl radicals and R33 is selected from hydrogen and methyl, and p is a whole number that varies from 0 to 3.
118. The method of claim 117 wherein the adhesion promoter has the formula
119. A method in accordance with claim 104 where the silane scavenger is methyldimethoxy-N-methylacetamido-silane.
120. A method in accordance with claim 104 where the silane scavenger is methyldimethoxyisopropenoxysilane.
121. A method in accordance with claim 104 where the silane scavenger is methyltriisopropenoxysilane.
122. A method in accordance with claim 104 using an effective amount of dibutyltindiacetate as the condensation catalyst.
123. In the method of making a substantially acid-free room temperature vulcanizable organopolysiloxane composition under substantially anhydrous conditions utilizing an effective amount of a condensation catalyst with an organopolysiloxane wherein the silicon atom at each polymer chain end is terminated with at least two alkoxy radicals, the improvement which comprises adding to said polyalkoxy-terminated organopolysiloxane (1) a stabilizing amount of a silane scavenger for hydroxy functional groups of the formula where R1 is a C(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylke-tone and alkylcyano radicals, or a C(7-13) aralkyl radical, R2 is a C(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thiosocyanato and ureido radicals, and c is a whole number equal to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive, and the sum of c + f is equal to 1 to 4 inclusive, and (2) an effective amount of a condensation catalyst, whereby improved stability is achieved in the resulting room temperature vulcanizable organopolysiloxane composition, and (3) where X is enoxy or amido, adding before or with the scavenger an effective amount of a curing accelerator selected from the group consisting of substituted guanidines, amines and mixtures thereof, and (4) from 2 to 20 parts by weight per 100 parts by weight of said organopolysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunctionality or mixtures of tri- and tetra-functionality comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units;
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
(ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent of dialkyl siloxy units, said polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
12. The method of claim 123 wherein said organopolysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
125. The method of claim 124 wherein there is further present from 5 to 60 parts by weight of a second plasticizer per 100 parts of said organopolysiloxane, said second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
126. The method of claim 125 wherein the said second plasticizer polymer has the formula where R20 is a monovalent hydrocarbon radical and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
127. The method of claim 126 wherein R20 is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
128. The method of claim 126 where there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
129. The method of claim 128 wherein the extending filler is calcium carbonate.
.
.
130. The method of claim 129 wherein the calcium carbonate is treated with stearic acid.
131. The method of claim 128 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organopolysiloxane of a reinforcing filler.
132. The method of claim 130 wherein the reinforcing filler is a first sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
133. The method of claim 132 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas and where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethylol-propane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000; y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
134. The method of claim 128 wherein there is present from 0.2 to 2.0 parts by weigh-t per 100 parts by weight of said organopolysiloxane of a sag control agent which is a hydrogenated castor oil.
135. The method of claim 124 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
136. The method of claim 123 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30 and R31 are selected from C(1-8) monovalent hydrocarbon radicals, R32 and R36 are selected from C(1-12) divalent hydrocarbon radicals, R38 and R40 are selected from the group consisting of hydrogen and C(1-6) monovalent hydrocarbon radicals, R34 is selected from hydrogen and C(1-3) alkyl radicals and R33 is selected from hydrogen and methyl, and p is a whole number that varies from 0 to 3.
137. The method of claim 136 wherein the adhesion promoter has the formula
138. A method in accordance with claim 123 where the silane scavenger is methyldimethoxy-N-methylacetamido-silane.
139. A method in accordance with claim 123 where the silane scavenger is methyldimethoxyisopropenoxy-silane.
140. A method in accordance with claim 123 utilizing a stabilizing amount of methyltriisopropenoxy-silane and an effective amount of methyltrimethoxysilane.
141. A method in accordance with claim 123 using an effective amount of dibutyltindiacetate as the conden-sation catalyst.
142. A stable, one-package, substantially anhydrous and substantially acid-free, room temperature vulcanizable organopolysiloxane composition stable under ambient conditions in the substantial absence of moisture over an extended period of time and convertible to a tack-free elastomer comprising: (1) an organopolysiloxane wherein the silicon atom at each polymer chain end of terminated with at least 2 alkoxy radicals; (2) an effective amount of a condensation catalyst; (3) a stabilizing amount of scavenger for hydroxy functional groups which is a silicon-nitrogen compound having at least two structural units selected from the group consisting of units of the formula and such nitrogen-containing structural groups comprising from 3 to 100 mole percent of the scavenger for hydroxy functional groups and from 0 to 97 mole percent chemically combined structural units represented by the formula where the silicon atoms of said silicon-nitrogen compound are joined to each other by a member selected from an SiOSi linkage and a SiNR''Si linkage, the free valences of said silicon atoms other than those joined to oxygen to form a siloxy unit and to nitrogen to form a silazy unit are joined to a member selected from an R''' radical and an (R'')2N radical, and where the ratio of the sum of said R''' radicals and said (R'')2N radicals to the silicon atoms of said silicon-nitrogen compound has a value of 1.5 to 3.5 inclusive, and R'' is a member selected from the class consisting of hydrogen, monovalent hydrocarbon radicals and monovalent fluoroalkyl radicals, R''' is a member selected from hydrogen, monovalent hydrocarbon radicals and monovalent fluoroalkyl radicals, and c is a whole number equal to 0 to 3, inclusive, and (4) from 2 to 20 parts by weight per 100 parts by weight of said organo-polysiloxane of a first plasticizer fluid polysiloxane containing a high degree of trifunctionality and mixtures of tri- and tetrafunctionality comprising (i) from 5 to 60 mole percent of monoalkylsiloxy units, siloxy units or a mixture of such units, (ii) from 1 to 6 mole percent of trialkylsiloxy units and (iii) from 34 to 94 mole percent dialkylsiloxy units said first plasticizer fluid polysiloxane containing from about 0.1 to about 2% by weight of silicon-bonded hydroxyl groups.
143. The composition of claim 142 wherein said organopolysiloxane has a viscosity in the range of 60,000 to 500,000 centipoise at 25°C.
144. The composition of claim 143 wherein there is further present from 5 to 60 parts by weight of second plasticizer per 100 parts of said organopolysiloxane, said second plasticizer being a linear triorganosiloxy end-stopped diorganopolysiloxane of a viscosity ranging from 10 to 20,000 centipoise at 25°C and the organo group is a monovalent hydrocarbon radical.
145. The composition of claim 144 wherein said second plasticizer polymer has the formula where R20 is a monovalent hydrocarbon radical and t varies such that the viscosity of the polymer varies from 10 to 20,000 centipoise at 25°C.
146. The composition of claim 145 wherein R
is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
is methyl and t varies such that the viscosity of the polymer varies from 10 to 10,000 centipoise at 25°C.
147. The composition of claim 145 wherein there is present from 100 to 300 parts by weight per 100 parts of said organopolysiloxane of an extending filler.
148. The composition of claim 147 wherein the extending filler is calcium carbonate.
149. The composition of claim 148 wherein the calcium carbonate is treated with stearic acid.
150. The composition of claim 147 wherein there is present from 1 to 50 parts by weight per 100 parts by weight of said organopolysiloxane of a reinforcing filler.
151. The composition of claim 149 wherein the reinforcing filler is a sag control agent and is fumed silica which is present at a concentration of 1 to 10 parts by weight per 100 parts of said organopolysiloxane.
152. The composition of claim 151 wherein there is present from 0.1 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a second sag control agent which is a polyether selected from the formulas A - O - (CXH2XC)n - B
and [A - O - (CXH2XO)n - y - QZ
where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms, radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethyl-olpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000; y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
and [A - O - (CXH2XO)n - y - QZ
where A and B represent radicals selected from the group consisting of hydrogen, alkyl radicals containing from 1 to 12 carbon atoms, cycloalkyl radicals containing 5 to 7 carbon atoms in the ring, mononuclear and binuclear aryl radicals, and mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms, radicals, where R is alkyl containing from 1 to 11 carbon atoms; Q is a residue of a polyhydric initiator radical containing at least two hydroxyl radicals selected from the group consisting of ethylene glycol, glycerol, trimethyl-olpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a whole number having a value of 2 to 4; n is an integer equal to from 4 to 2000; y has a value of from 2 to 10; and z has a value of from 1 to 5; the polyether having a molecular weight of from about 300 to about 200,000.
153. The composition of claim 147 wherein there is present from 0.2 to 2.0 parts by weight per 100 parts by weight of said organopolysiloxane of a sag control agent which is a hydrogenated castor oil.
154. The composition of claim 150 wherein the reinforcing filler is treated with cyclopolysiloxane prior to incorporation in the composition.
155. The composition of claim 142 wherein there is present from 0.1 to 10 parts by weight of an adhesion promoter which has the formula where R30 and R31 are selected from C(1-8) monovalent hydrocarbon radicals, R38 and R40 are selected from the group consisting of hydrogen and C(1-6) monovalent hydrocarbon radicals, R33 is selected from hydrogen and C(1-3) alkoxy radicals and R33 is selected from hydrogen and methyl, R32 and R36 are selected from C(1-12) divalent hydrocarbon radicals and p is a whole number that varies from 0 to 3.
156. The composition of claim 155 wherein the adhesion promoter has the formula
156. The composition of claim 155 wherein the adhesion promoter has the formula
Claim 156 continued:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000423365A CA1195033A (en) | 1983-03-11 | 1983-03-11 | Low modulus one-component rtv compositions and processes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000423365A CA1195033A (en) | 1983-03-11 | 1983-03-11 | Low modulus one-component rtv compositions and processes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1195033A true CA1195033A (en) | 1985-10-08 |
Family
ID=4124758
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000423365A Expired CA1195033A (en) | 1983-03-11 | 1983-03-11 | Low modulus one-component rtv compositions and processes |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1195033A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0337791A2 (en) * | 1988-04-15 | 1989-10-18 | Dow Corning Corporation | Self leveling highway sealant |
| EP0337792A2 (en) * | 1988-04-15 | 1989-10-18 | Dow Corning Corporation | Flowable joint sealant for concrete highway |
| JP2014532091A (en) * | 2011-09-16 | 2014-12-04 | ブルースター・シリコーンズ・フランス・エスアエス | Methods and compositions for sealing and assembly of powertrain components |
-
1983
- 1983-03-11 CA CA000423365A patent/CA1195033A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0337791A2 (en) * | 1988-04-15 | 1989-10-18 | Dow Corning Corporation | Self leveling highway sealant |
| EP0337792A2 (en) * | 1988-04-15 | 1989-10-18 | Dow Corning Corporation | Flowable joint sealant for concrete highway |
| EP0337792A3 (en) * | 1988-04-15 | 1990-01-24 | Dow Corning Corporation | Flowable joint sealant for concrete highway |
| EP0337791A3 (en) * | 1988-04-15 | 1990-09-12 | Dow Corning Corporation | Self leveling highway sealant |
| JP2014532091A (en) * | 2011-09-16 | 2014-12-04 | ブルースター・シリコーンズ・フランス・エスアエス | Methods and compositions for sealing and assembly of powertrain components |
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