CA1117239A - Compositions containing diorganopolysiloxanes - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE A composition is provided herein containing diorganopolysiloxanes and copolymers derived from monomers consisting of at least ethylene and vinyl acetate in which the copolymer consists of from 30 to 40 percent by weight of units derived from ethylene,from 57.5 to 70 percent by weight of units derived from vinyl acetate and from 0 to 3.5 percent by weight of units derived from a monomer other than ethylene and vinyl acetate which is capable of being polymerized in the presence of a free radical initiator, The copoly-mer has been prepared in the presence of the diorganopolysiloxane and being present in the composition in an amount of from 65 to 85 percent by weight based on the weight of the copolymer and the diorganopolysiloxane.

Description

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` m is invention relates to diorganopolysilQxane com~osi-tions and more particularly to compositions contaLning diorganopolysiloxanes and co-polymers which are prepared in the presence of the diorganopolysiloxanes.
More specifically the invention relates to diorganopolysiloxane compositions containing copolymers which are derived from monomers consist-ing of at least ethylene and vinyl acetate and to a process for preparing the diorganopolysiloxane com~ositions.
Compositions containing diorganopolysiloxanes and a polymer ~hich is prepared in the presence of the diorganopolysiloxanes have been known heretofore. For example, it has been known that mono-mers containing ali-phatic unsaturation can be polymerized in the presence of diorganopolysilox-anes and free radical initiators. In U.S. Patent No. 4,026,853 issued May 31, 1977 to l)re~snandt et al several patents are disclosed which describe the preparation of modified organopolysiloxanes by polymerizing monomers containing aliphatic unsaturation in the presence of organopolysiloxanes and free radical initiators. m e patent also discloses a large number of monomers containing aliphatic unsaturation, including ethylene and vinyl acetate which may be employed in the~ polymerization. ~Iowever, the prepara-tion of ethylene and vinyl acetate copolymers in ~the presence of diorgano-polysiloxanes has not been known heretofore.
Compositions prepared heretofore from the polynx~:ization of mono-mers containing aliphatic unsaturation in the presence of diorganopolysilox anes and free radical initiators have several disadvantages. For example, these compositions are not stable, i.e., they migrate on vertical or in clined surfaces and flow out of vertical fissures. In order to overcome these disadvantages, it was necessary to add fillers, e.g. described in U.S. Patent No. 3,580,971 issued May 25, 1971 to Getson. Also, U.S. Patent No. 3,776,875 issued Dec. 4, 1973 to Getson discloses that polymerization ~ `

composit-ions prepared in tha presence of solvents are thixotropic and will not migrate on vertical surfaces. One of the disadvantages of adding fillers is that they may produce an undesirably high viscosity or lead to solidifi-cation of the compounds. In addition, incorporation of fillers ~nto the compositions substantially increases the cost of the products.~ Likewise, compositions obtained from the polymerization of methacrylic acid in the presence of diorganopolysiloxanes must contain an undesirably high percentage of diorganopolysiloxane, otherwise they will have an undesirably high viscosity. Moreover, when a solvent is employed in the polymerization~the resultant products, when molded, have a tendency to shrink as the solvent evaporates.
Therefore, it is an ob~ect of onè aspect of this invention to pro- ' vide organopolysiloxane compositlons.
An ob~ect of another aspect of this invention is to provide com-positions containing diorganopolysiloxanes and copolymers derived from monomers consisting of at least ethylene and vinyl acetate.
An ob;ect of still another aspect of this invention is to provide compositions in which the copolymers may be bonded to or dispersed in, and/
or-both bonded to and dispersed in the diorganopolysiloxane.
An ob~ect of further aspect of this invention is to ~
provide organopolysiloxane compositions which will no~ significantly migrate on the surface even in the absence of fillers.
An object of a still further aspect of this invention is to provide a process for preparing diorganopolysiloxane compositions having copolymers bonded-to, or dispersed in, or both bonded to and dispersed in the diorgano-polysiloxanes in which the copolymers derived from monomers consisting of at least ethylene and vinyl acetate are prepared in the presence of dior-ganopolysiloxanes and free radical initlators.
In accordance wlth one broad aspect of this invention, an organo-A~, A

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polysiloxane composition is provided containing diorganopolysiloxanes and copolymers derived from monomers consisting of at least ethylene and vinyl acetate, in which the copolymer consists of from 30 to 40 percent by weight of units derived from ethylene, from 57~5 to 70 percent by wei&ht of units derived from vinyl acetate and from 0 to 3.5 percent by weight of units de-rived from a monomer other than ethylene and vinyl acetate which is capable of being poly~erized in the presence of a free radical initiator the copoly-mer having be~n prepared in the presence of the diorganopolysiloxane and being present in the composition in an amount of from 65 to 85 percent by weight based on the weight of the copolymer and the diorganopolysiloxane.
By a variant thereof, diorganopolysiloxanes are preferably those represented by the general formula ZnSiR3_nO(siR2o)xsiR3-n n in which R is selected from the same or dlfferent monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radi-cals, Z is selected from the class consisting of hydroxyl groups, hydrolyza-ble groups and hydrolyzable atoms, n is 0, 1, 2 or 3 and x is 0 or an inte-ger of at least 1.
By a variation thereof Z represents a hydrolyzable group.
By another variation, Z is selected from the class consisting of acyloxy, hydrocarbonoxy, substituted hydrocarbonoxy, hydrocarbonoxy-hydro-carbonoxy, aminoxy, amino, acylamino, oxime and phosphate groups.
By a further varia~ion, Z represents hydroxyl groups.
By yet another variation, one of the R radicals on each of the terminal silicon atoms is a vin~l group and n is 0.
By another aspect of this invention, a room temperature curable composition is provided which is stored under anhydrous conditions and which, when exposed to atmospheric moisture, cures to an elastomeric solid, ~he composition comprising ta) the composition descrlbed above and (b~a silicon compound having at least three hydrolyzable groups per molecule.

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. . By a variant thereof, the composition contains also a condensation catalyst.
By still another aspect, a curable composition is provided comprising the composition as described above (b) a crosslinking agent selected from the class consisting of silanes of the formula R ,Si~OZ~)4 n~
and siloxanes, the silanes being liquid at room temperature and contain at least three SiOZ' groups and the remaining silicon atoms on the siloxanes - which are not linked to siloxane oxygen atoms, OZ' groups or hydrogen atoms are satisfied by R groups and (c) a condensation catalyst, in which R is selected from the class consisting of monovalent hydrocarbon radicals, halo-genated monovalent hydrocarbon radicals and cyanoalkyl radicals, Z' is selec-ted from the class consisting of a hydrocarbon radical and a hydrocarbon radical containing an ether oxygen atom and n' is O or 1.

By still another aspect of this invention a curable composition is provided comprising the composition as described above and (b) an organo-polysiloxane which contains at least three Si-bonded hydrogen atoms per molecule; and (c) a catalyst which promotes the addition of Si-bonded hydro-gen to the vinyl groups.

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.- ~ By a variant thereof, ths organopolysiloxane containing at least thres Si-bonded hydrogen atoms per molecule is present in an amount of :- - from 0.5 to 20 percent by weight based on the weight of the organopolysilox-, anes.
By another aspect, a process is provided for preparing such com-positions by polymeriæing at a temperature of from 30 to 70qC, at least two monomers having aliphatic unsaturation consisting of ethylene and vinyl acetate in the presence of a diorganopolysiloxane and free radical initia-tors, in which vinyl acetate is present in an amount of from 50 to 75 per-cent by weight based on the weight of vinyl acetate and diorganopolysilox-ane and the total volume of vinyl acetate and diorganopolysiloxane does not exceed 60 percent of the total volume of the polymerization device and the ethylene is present at a pressure of from 40 to 70 bar.
~ y a variant thereof, monomers other than ethylene and vinyl ace-tate which are capable of being polymeriæed in the presence of free radical initiators are present in an amount of up to 5 percent by weight based on - 5 a -,.J~
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the weight of the vinyl acetate.
In contrast to the compositions described heretofore, the composi-tions of aspects of this invention are stable in the absence of fillers or polymethacrylic acids. Moreover, it is no longer essential that the compo-sitions be prepared in the presence of solvents in order to obtain the de-sired stability. Likewise, these compositions are stable in the absence of other materials, e.g. cross-linking agents.
The composition is preferably prepared by polymarizing at least two monomers consisting of vinyl acetate and ethylene in the presence of diorganopolysiloxans and a free radical initiator at a temperature of from 30 to 70C. In the polymerization reaction, the vinyl acetate is preferably present in an amount of from 55 to 75 percent by weight based on the weight of the vinyl acetate and the diorganopolysiloxane, and the vinyl ace-tate and diorganopolysiloxane constitute up to 60 percent by volume of the polymerization vessel and the ehtylene is employed at a pressure of from 40 to 70 bar.
It is preferred that R radicals contain from 1 to 7 carbon atoms.
Examples of suitable hydrocarbon radicals represented by R are alkyl radi-cals, e.g. methyl, ethyl, propyl, butyl, and hexyl radicals, cycloalkyl radicals, e.g. the cyclohexyl rad~cal and aryl radicals e.g. the phenyl and tolyl radicals. It is preferred that lakenyl radlcals e.g. the vinyl radical or allyl radical be present only in the terminal units.
Substituted hydrocarbon radicals represented by R are generally halogenated hydrocarbon radicals or cyanoalkyo radicals. Examples of sub-stituted hydrocarbon radicals are the 3,3,3-trifluoropropyl radical, chloro-phenyl radicals and beta-cyanoethyl radical. Because they are more readily available, i~ is preferred that at least 80 percent of the R radicals be methyl radicals.

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The hydrolyzable groups represented by Z can be the same hydrolyza-ble groups as are present in the hydrolyzable silicon compounds whlch are generally employed in the prepara~ion of compoùnds which can be stored under anhydrous conditions, but when exposed to moisture at room temperature, cure to an elastomeric solid, Examples of suitable hydrolyzable groups are acyloxy groups ~-00CR'), hydrocarbonoxy and substituted hydrocarbonoxy groups (-OR'), hydrocarbonoxy-hydrocarbonoxy groups ~-OR"OR'), where R" is a dival-ent or substituted divalent hydrocarbon radical9 e.g, the ethylene radical, aminoxy groups (-ONR'2), amino groups, for example -NR'2, acylamino groups, for example-NR'COR', oxime groups (-ON=CR'2 and phosphate groups [-0~l(OR')2~

o formulas, R' represents the sama or different monovalent or substituted mono-valent hydrocarbon radicals and hydrogen atoms. Examples of hydrocarbon `
radicals represented by R, are equally applicable for hydrocarbon radical R' and examples of substituted hydrocarbon radicals represented by R, are ~qually applicable for substituted hydrocarbon radicals R'.
Examples of acyloxy groups are especially acyloxy groups having from 1 to 18 carbon atoms, e.g. formyloxy, acetoxy, propionyloxy, valeroy-loxy, caproyloxy, myristoyloxy and stearoyloxy groups.
Examples of hydrocarbonoxy groups are alkoxy groups having from 1to 10 carbon atoms, e.g. methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, heptyloxy and octyloxy groups. Other examples of hydrocarbonoxy groups having from 1 to 10 carbon atoms are vinyloxy, allyloxy, ethylallyloxy, iso-- propenyloxy, butadienyloxy and phenoxy groups.
The bast known example of a hydrocarbonoxy-hydrocarbonoxy group is the methoxyethyleneoxy group. Examples of am~noxy groups arc dimethyl-aminoxy, diethylaminoxy, dipropylaminoxy, dibutylaminoxy, dioctylaminoxy, . ' ~ . :
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diphenylaminoxy, ethylmethylaminoxy and methylphenylaminoxy groups.
- Examples of amino groups are n-butylamino, sec,-butylamino and cyclohexylamino groups.

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An e~l~lple of an acylamino group is the benzoylmethylamino group.
Examples of oxime groups are acetophenono~uune, acetonoxime, benzophenonoxime, 2-butanonoxime, diisopropylketoxime and chlorocyclohex-anonoxLme groups.
Exan~les of phosphate groups are dime-thylphosphate, diethylphos-phate, dibu-tylphosphate, dioctylphosphate, methylethylphosphate, me-thyl-phenylphosphate and diphenylphosphate groups.
Examples of hydrolyzable Z atoms are halogen aboms, e.g. chlor me atoms as well as hydrogen atoms.
I-t is preEerred that Z represent hydroxyl groups and that n have a value of 1. ~Icwever, if one o the R radicals in the two terminal units is a vinyl group, or if each of the R radicals is a methyl group, then n has a value of 0.
The value of X can be 20,000 or even higher, so long as the diorganopolysiloxanes are still flowable, even in -the presence of solvents.
` Although this is not indicated in the follcwing formula, ZnSiR3_n~SiR20~xSiR3_nZn, where R, Z, n and x are the same as above, small amounts of siloxane units other than diorganosiloxane units may be present within the siloxane chain. Such other units are often present only as impurities and not usually in am~unts exceeding 10 mol } cent.
m e ratio of the number of R radicals to the num~er of Si-a~oms preferably ranges from about 1.9 up to 2.25.
m e diorganopolysiloxanes employed in accordance with the process of aspects of this invention and the diorganopolysiloxanes which are pre-sent in the com~ositions of aspects of this invention can be homopolymers or copolymers. EX~mples of preferred diorganopolysiloxane~ are dimethyl-polysiloxanes and o~polymers consisting of dimethylpolysiloxane units and methylphenylsiloxane units and/or diphenylsiloxane units, in which the :: - : .

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polymers or copolymers are -terminated with Si-bon~ed hydroxyl groups.
m e diorganopolysiloxanes used in the process of an aspect of this invention and the diorganopolysiloxanes present in the resultant comr positions can, however contain sQme diorganopolysiloxanes which are not covered by -the previously cited formula. ~n example oE such a diorgano-polysiloxane which may be present is ocbamethylcyclotetrasilQxane.
Moreover, up to 50 percent by weight, and ~Dre preferably up to 20 percent by weight of the diorganopolysiloxanes used in the process of an aspect of this invention can be of a type ~hich is linked by ~ ,. .

chemical bonding to organic polymers other than organopolysiloxanes, i e graft polymers and/or block-copolymers Diorganopolysiloxanes which are linked by chemical bonding to organic polymers other than l organopolysiloxanes and which constitute graft polymers, have ¦ organopolysiloxane chains as the principal chains or "backbones"
¦ and at least one side chain which consists of an organic polymer other than an organopolysiloxane. In the block-copolymers in which l diorganopolysiloxanes are linked by chemica,l bonding to organic ¦ polymers other than organopolysiloxanes, the blocks or segments ¦ which consist of diorganopolysiloxane units alternate with blocks lor segments of an organic polymer other than the diorganopolysi-¦loxane. The principal organopolysiloxane chains or "backbones"
¦may be illustrated by the above general formula if at least one of ¦the R radicals is a bivalent, or substituted bivalent hydrocarbon ¦radical to which a polymeric organic radical other than an organo-¦polysiloxane radical is bonded thereto with the provision that x Iis at least 20. Furthermore, the blocks or segments made up of ¦diorganopolysiloxane ur,its may also contain units of the general ¦formula:
l -(SiR20)X~siR2-~
¦where R is the same as above and x' is an integer having a value ¦of at least 1, and more preferably having a valu~ of at least 20.
¦~lhen the diorganopolysiloxanes are chemically linked to the organic ¦polymers, they are generally linked through an;SiC or an SiQC
¦linkage. II The organic polymers which are chemically linked to ¦the diorganopolysiloxanes can be polymerizatiol products, polycon-¦densation products or polyaddition products. Examples of organic polyoondensation products other than organopolysiloxanes or of polyaddition products or of p~lymerization products are polyester, polyether, poly~re-thane and polymers containing aliphatic unsaturation in which the organic polymers are chemacally linked to the diorganopolysiloxanes. These comr positions are generally known and procedures for their preparation are described in German Patent Specification 14 95 531 to Dow Cornang Corpora-tion. Other patents which describe the preparation of compositions in which the organic polymers are chemically linked and/or dispersed in the diorgano-polysiloxanes are U.S. Patents 3,355,109 issued ~ov. 28, 1967 to Kane;
3,776,875 issued Dec. 4, 1973 to Getson; 3,627,836 issued Dec. 14, 1971 to Getson and 3,631,087 issued Dec. 28, 1971 to ~ewis et al. Compositions and processes for preparing compositions ~n which the organic polymers are chemically linked to and,or dispersed in the diorganopolysiloxanes are disclosed in German Patent Specifications Nos. 20 38 519; 21 16 837 to general Electric Ccmpany; U.S.S.R. Certificate 222,664; U.S. Patent No.

2,965,593 issued Dec 6, 1960 to Suran et al; British Patent No. 1,261,484 dated Jam. 26, 1972 to Dow Cbrnang Corporation and German Patent Specifi-cation No. 24 59 809 to General Electric Company.
It is preferred that each organic polymer which is chemically bonded to across-linked diorganopolysiloxane oontain at least 20 polymer units in the chain for each side chain or segment. Furthermore, it is preferred that -the diorganopolysiloxanes which are linked with organic polymers by a chemical kond, be generated only during the preparation of the cojposition of this invention, i.e., that the organic polymers which are linked with the diorganopolysiloxane by chemical bonding contain re-curring units whichlare derived fram vinyl acetate, ethylene and possibly other monomer which polymeriæable in the presence of free radicals and that they may be linked to the diorganopolysiloxane by SiC bonding.
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11~ 39 It is assumed that the polymerization of the vinyl acetat~
and ethylene and possibly at least one other monomer in the presenc~
of the diorganopolysiloxanes and a free radical initiator produce a s~able dispersion in which the resultant copolymer is bonded to and/or dispersed in the diorganopolysiloxanes.
The organopolysiloxanes employed ln the process of an aspect of this invention are preferably liquids which can be stirred at the poly-merization temperature. It is preferrecl that their average viscosit be from 100 to 1000 cP at 25~C.

Although only one type of diorganopolysiloxane can be used mixtures consisting of several diorganopolysiloxanes may be employed It is preferred that the vinyl acetate be employed ~n mounts of from 65 to 70 percent by weight based on the total weight f t.he dioranopolysiloxane and the vinyl acetate. It is also referred that the pressure of the ethylene be on the order of from 0 to 60 bar.
In the process of an aspect of this invention, 5 percent by weight ased on the weight of the vinyl acetat~ employed may consist of monomers other than ethylene and vinyl acetate which can be poly-merized in the presence of free radicals.
Examples of other monomers which can be polymerized in he presence of free radicals with the ethylene and vinyl acetate, re polymerizable aliphatic hydrocarbons, e.y-, propylene and utylene; vinyl halides, e-g-, vinyl fluorideland vinyl chloride;
inyl esters of organic acids, e.g.,- vinyl propionate and vinyl aurate; styrene, substituted styrenes, as well` as other aromatic inyl compounds and heterocylic vinyl compounds, e-g-~ _, vinyl aphthalene and vinyl pyridine; acrylic acids and acrylic acicl - lla ~

:~LI~7Z39 derivates, e-g., acrylic acid salts, esters and amides; as well as acrylonitrile, N-vinyl compounds, e.y., N-vinylcarbazole, N-vinylpyrrolidone and N-vinyl caprolactam; vinyl groups which contain silanes, e.q., vinyltriethoxysilane; symmetrically di-substituted ethylenes, e.~., vinylene carbonate and stilbene, as well as asymmetrically disubstituted ethylenes, e.~., vinyl-idene cyanide, methacrylic acid and methacrylic acid derivatives, - e.g., methacrylic acid salts, esters and amides; as ~ell as methacrylonitrile and methacrolein and allyl compounds, e.g., allyl chloride, allylesters and alkyl amides of organic aids.
It is preferred that organic peroxides be employed to initiate the formation of free radicals. However other compounds can be used as well; for example azo compounds, in which the two nitrogen atonns of the azo group are bonded to tertiary carbon atoms nd where the unsaturated valences of the tertiary carbon atoms re saturated by nitrile, carboxyl, cycloalkylene or alkyl groups, referably having from 1 to;10 carbon atoms. Also, free radicals an be generated by means of high energy rays, e.g., alpha, beta r gamma rays or UV-rays.
Examples of preferred free radical forming compounds are iacylperoxides, e.g., benzoylperoxide and lauroylperoxide, keto-eroxides, e g , -cetone peroxide and cyclohexanone peroxide;
ydrocarbon hydroperoxides, e.g., tert-butyl hydroperoxide, umene hydroperoxide and decahydronaphthalene hydroperoxide, dialkyl eroxides, e.g., di-tert-butyl peroxide and dicumyl peroxide;
erketals, e.g., l,l,-di-tert-butyl peroxide-3,3,5-trimethyl-yclohexane; peresters, e.g., tert-butyl perbenzoate; tert-butyl eroxyisopropyl carbonate, tert-butylperpivalate, tert-butyl 1~L~Z3 9 peroctoate, tert-butylcyclohexyl percarbonate and tert-butyl permaleinate and acetylcyclohexanesulfonyl peroxide.
Mixtures of these ~ree ~adical formin~ compounds may also be used in the process of an aspect of this invention.
It is preferred that the high energy rays be used in such an amount that no more than lO-2 mol radicals per hour are formed for each liter of reaction mixture and more preferably no more than 5xl0-4 mol radicals per liter per hour of reaction mixture. The free radical initiator is preferably used in amount of from 0.005 to 5 percent by weight and more preferably, in amounts of from 0.00 to 2 percent by weight based on the total ~eight of the vinyl aceta-~
nd the diorganopolysiloxane employed.
Preferably the reaction is conducted at a temperature of from 45 to 55C. However, temperatures of from ~ 30 to ab~u-t~
lO0C may be employed if desired. Although compounds may be mployed to control the molecular weight, it is preferred that the reaction be conducted in the absence of these compounds. It is preferred that the reaction be conducted in the absence of solvents however, relatively small amounts of so`lvent may be employed to obtain a homogeneous distribution of the -free radieal initiators among the reactants. Nevertheless, the use of solvents, especially in an amount up to 20 percent by ~eight based on the total weight of the vinyl ~cetate and the diorganopolysiloxane used in th~
weight of the vinyl acetate and the diorganopolysiloxane used in the pro-cell os an aspect of this invention should ~y no ~cans be excluded. ~hen solvents are used, it is preferred th~t solvents having the lowest possible chain transfer constant be employed. E~amples oE such solvents are ali phatic hydrocar~onsr e.g., hexane or benzene muxtures; esters, e.g., mekhyl acetate and/or ethyl acetate and/or ~ ~ 7'~ 3 alcohols, e.g., tert-butanol.
The copolymers consisting o-~ vinyl acetate, ethylene and if desired at least one monomer which can be polymerized by means of free radical initiators, are generally present in the form of minute spheres and/or irregular structures having a diameter of 0.1 to 100 mm. The formation of these particles is not dependent on the method or type of stirring.
In addition to the copolymer consisting of vinyl acetate,`
~ ethylene and if desired at least one other monomer which can be ¦polymerized in the presence of free radical initiators, the dior-¦ganopolysiloxane in whose presence the copolymer is prepared and possibly diorganopolysiloxane which is linked by chemical bonding to an organic polymer other than organopolysiloxane, as well as solvents, the cc~nFositions o~ aspects of this ~nve~tion may conta m or be mixed with other substances , e.g., diorganopolysiloxanes of the formula:
ZnSi R3_nO(Si R20)XSi R3-nZn where R, Z, n and x are the same as above except that n has a value of 0 or one of the R radicals in the two terminal units is a vinyl group and n has a value of 0. These substances may be employed in an amount in excess of 35 percent by weight based on the total eight of the copolymer consisting of at least vinyl acetate, ethyl-ene and one other monomer when present and the diorganopolysiloxane, and up to 99 percent by weight, based on the total weight of the flowable, composition including fillers, cross-linking agents, cross-linking catalysts, pigments, heat stabilizers, antioxidants, ultraviolet absorbers, emollients and cell-generating compounds, es.
a-s- azodicarbonamide, as well as bituminous materials.

11~7Z39 Fillers which may be included in these compositions are reinforcing fillers, i.e., fillers having a surface area of at leasl 50 m2/gm. Examples of suitable fillers are precipitated silicon dioxide having a surface area of at least 50 m2/gm and/or pyrogen-ically produced silicon dioxide.
A portion of the fillers can be non-reinforced fillers, i.e., fillers which have a surface area of less than S0 m2/gm.
Examples of non-reinforced fillers or pigments are diatomaceous earth, bentonite, quartz meal, crystobalite meal, pigment grade titanium dioxide, ferric oxide and zinc oxide. Fibrous fillers, e.g.
: -asbestos and glass fibers may also be incorporated in the compo-sitions of aspects of this invention. The fillers may ~r example be treated .
with trimethylethoxysilane in a ball mill to coat the surfaces with organosiloxy groups. However, it is preferred that reinforcing fillers be omitted from these c-omposition. When reinforcing fillers are employed however, it is preferred that they be present in an amount less than 50 percent by weight based on the total weigh of the fillers and all other components.
Suitable examples of emollients are phthalic, adipic, sebacic, citric or phosphoric acid esters having from 1 to 30 carbon atGms per molecule of aliphatic or aromatic alcohols. IndiYidual examples of such emollients are dioctyl and didecylphthalate, dioctyl and didecyladipate, dioctyl sebacate~ trioctylcitrate, tricresyl phosphate and trixylenylphosphate. The use of emollients which are either entirely immiscible with the diorganopolysiloxane or only just slightly miscible with the diorga;opolysiloxane is referred, since these emollients surprisingly do not decrease the stability of the oompositions of aspec-ts of this invention. When an emollient _14_ is employed, it ;s preferably employed in an amount less than 25 percent by weight based on the total weight of the emollient a~d the other components. ~en the compositions of aspects of this invention ¦¦contain emollients, they are especially suited for the sealing of ¦¦fissures which are subject to stress as the result of expansion.
Even when t~e comFositions of asEects of ~his invention do not contain organopolysiloxanes having hydrolyzable groups or hydroly-zable atoms or crosslinking agents and possibly crosslinking catalysts, they constitute valuable coating agents for electronic devices or lubricants or components of lubricants which are .
superior to the pastes known heretofore which consist of trimethyl-siloxy endblocked dimethylpolysiloxanes and silicon dioxide havin~ a surface area of at least 50 m2/gm.
When the organopolysiloxanes in the com~ositions of as~ects of ~

invention contain at least three hydrolyzable groups and/or hydroly-zable atoms per molecule, these compositions can be stored under anh drous conditions, but when exposed to moisture at room temperature ?
they crosslink to form elastomers. The moisture present in normal atmospheric air is sufficient to cause these compositions to cross-link.
'~hen the organopolysiloxanes pres~nt in the compositions of aspects of this invention have tw~ Si-konded hydroxyl groups per ~,olecule, these compositions can be crosslinked at room temperature to form elastomers by the addition of crosslinking agents which contain at least three condensable groups and/or condensable atoms per molecule, and condensation catalysts when desiled.
The addition of the crosslinking agents containing at least 3 condensable groups and/or condensable atoms per molecule ~ ~ 7~39~

and condensation catalysts when desired, provides a composition which must be molded more or less immediately following the add;tion of the crosslinking agents and catalysts. These compositions constitute the so called "two-component systems". Also, crosslinkin agents and catalysts when desired may be used to prepare composition which can be stored under anhydrous conditions and which cure spontaneously to form elastomers, when exposed to atmospheric moisture at room temperature. These compositions constitute the so called "one-component systems".
One-component systems can be PrePared under anhydrous con-ditions, by mixing the compositions of aspects of ~s invention which contain diorganopolysiloxanes having two Si-bonded hydroxyl groups, wjth pol functional silicon compounds having at least 3 hydrolyzable groups per molecule, and condensation catalysts, if desired. Examples of ;
such polyfunctional silicon compounds are methyltriacetoxysilane, -tetracetoxysilane, methyl-tert-butoxyacetoxysilicon compounds havint a total of three tert-butoxy and acetoxy groups per molecule, methyl tris(cyclohexylanlino)-silane~ methyltris-(sec butylamino)silane, isopropoxytriacetoxysilane, methyltris-(2-butanonoximo)silane, methyltris-(diethylphosphato)-silane and methyltris-(isopropylamino) silane, as well as methyltris-(diethylaminoxy)-silane.
Two-componen~t systems can be prepared by mixing the comp?sitions of asPçcts of this invention co.n~.;.nin~ ora~.nQ~lysil~xanes hav~g¦two Si-bonded hydroxyl groups per molecule, with crosslinking agent ¦and condensation catalysts. Examples of suitable crosslinking ¦agents are silanes of the formula:
I Rn,si(OZ )~-n' 111'7Z39 where R is the same as above, Z' is a hydrocarbon radical or a hydrocarbon radical containing an ether oxygen atom, and n' is O
or 1, or siloxanes which are liquid at room temperature and which contain at least three SiOZ' groups and/or at least three Si-bonded hydrogen atoms per molecule, and the silicon atoms not linked to siloxane oxygen atoms, -0~' groups and hydrogen a-toms are satisfied by R groups.
Suitable examples of crosslinking agents which may be employed in the preparation oF two-component systems are methyl-triethoxysilane, tetraethoxysilane, "ethylsilicate 40", i.e., an ethylpolysilicate having an SiO2 content of approximately ~0 per-cent by weight, isopropylpolysilicates, methylbutoxydiethoxysilane, methyltris (methyloxyethyleneoxy)-silane and methylhydrogenpoly-siloxanes.
In the preparation of the one-component and two-component systems, the polyfunctional silicon compounds are generally used in amounts of from 0.5 to 20 percent by weight and more preferably-from 1 to 10 percent by weight based on the weight of the organopoly-siloxanes.
Examples of suitable condensation catalysts are metal carboxylic acid salts or organometal carboxylic acid salts of metals selected from lead to manganese of the electrochemical series, (cf.
llandbook of Chemistry and Physics, 31 Ed., Cleveland, Ohio, 1949, page 1465). Examples of preferred catalysts are tin compounds e.g., dibutyltin dilaurate, dibutyltin diacetate, tin-II-octoate, a mixture of dibutyltin diacylates~ where the acylate group is derived From carboxylic acids having from 9 to 11 carbon atoms per molecule and the carboxyl group in at least 90 percent by weight of .

the acids is ko~ded to a tertiary carkon atom; dibu-tyltin dioctoate, dis-t-~n-noxanes, e.g., diacetoxytetrabutyl distannoxane and dioleoyltetramethyl distannoxane. Other catalysts are ferric octoate, lead octoate, lead laurate and cobaltnaphthenate; titanium esters, e.g., titrabutyl titanate;
am mes e.g., n-hexylamine; amine salts e.g., n~hexylamine hydrochloride and n-butylamino acetate.
When one or tw~-componen-t systems are prepared, the condensation catalysts are generally employed in an amount of from 0.2 to 10 percent by weight based on the weight of the organopolysiloxanes.
Crosslinking can be accelerated by applying heat or where the compounds are crosslinked by water, then water in addition to that oontained in -the atmosphere or carbon dioxide may be added.
When the diorganopolysiloxanes contained in the com~ositions of a y cts of this invention have aliphatically unsaturated terminal groups bonded to silicon via carbon, then they can be crosslinked by the addition of organopolysiloxanes which contain at least three Si bonded hydrogen atoms per molecule and catalysts which prcm~te -the addition of Si-konded hydrogen or aliphatic m~ltiple bonds at room -te~erature or at elevated temperatures, generally not in excess~of 100C.
A preferred example of organopolysiloxanes containing at least three Si-bonded hydrogen atoms per molecule which may be used for cross-linking organopolysiloxanes having aliphatically unsaturated groups bonded to silioon via carkon, is methylhydrogenpolysiloxane.
Organopolysiloxanes containing at leas-t three Si-bonded hydrogen atoms per ~olecule which are used for crosslinking organo-: ~ .. . ..

: , .

polysiloxanes having groups which contain aliphatically unsaturated groups that are linked to silicon via carbon are preferably employed in an amount of from 0.5 to 20 percent by weight and more preferabl~
l in an amount of from 1 to 10 percent by weight based on the weight c ¦ the organopolysiloxanes.
Examples of catalys-ts which promote the acldition of Si-¦bonded hydrogen to aliphatic multiple bonds are platinum, platinum ¦supported catalysts, e.g., platinum on silicon dioxide or activated ¦charcoal and platinum compounds , e.g., chloroplatinic acid as well ¦as the products or complexes obtained from the reaction of chloro-¦platinic acid and organic and silicon organic compounds and/orinorganic compounds. The reaction products or complexes can be free of inorganic halogen. Specific examples are reaction products of chloroplatinic acid and ketones, e-g-~ cyclohexanone and platinum complexes in whic~ platinum is chemically bonded to 1,3-divinyltetramethyldisiloxane. Platinum and platinum cornpounds, including the reaction products and complexes, are preferably employed in amounts of from 0.5 to 500 ppm ~parts by weight per million parts by weight), calculated as Pt based on the weight of the organopolysiloxanes. Other examples of catalysts which promote the addition of Si-bonded hydrogen to aliphatic multiple bonds are rhodium compounds and rhodium complexes, iridium compounds and iridium complexes as well as cobalt and manganese carbonyls.
Regardless of whether or not the organopolysiloxanes .
'~Ised in the com~ositions of aspects of this in~ention cont~n a.1.. i.nhati.c~ :
unsaturated groups, Si-bonded hydroxyl groups or hydrol.yzable groups and~or hydrolyzable atoms, the compositions of aspects of this invention ¦~and/or the compositions prepared in accordance with the process of an aspec t of I l~Llt7Z3~

this invention can be crosslinked by means of free radicals formed by the conventional techniques. Thus, crosslinking can be carried out in the presence of the free radical~forming chemical and non-I chemical medium mentioned heretofore.
¦ In order to facilitate the dispersion of the crosslinking ¦agents and/or crosslinking catalysts in the compositions, the cross-¦linking agents and/or the crosslinking catalysts can be dissolved lor dispersed in a solvent which is inert with respect to the cross-¦linking agent or the catalysts employed. Examples of suitable sol-¦vents or dispersing agents are organopolysiloxanes, e.g. dimethyl ¦polysiloxanes having trimethylsiloxy terminal groups, and organic solvents which evaporate at room temperature. Examples of suitable organic solvents are chlorinated hydrocarbons e.g. trichloro~
ethylene. ~Ihen organic solvents or chlorinated organic solvents are~
employed, they are preferably employed in an amount of less than 20 percent by weight based on the weight of the composition to be crosslinke~.
The compositiolls oE aspects of t~-is invention contain up to 35 percent by weight of diorganopolysiloxanes based on the total weight of the copolymer which comprises vinyl acetate, ethylene and possibly one other monomer and the diorganopolysiloxanes. The compositions oE asl)octs of this invention, can be employed in the prel7aration of molds, including those used for the manufacture of articifial teeth, concrete and furniture elements, gaskets, electrical insula-tion items, including coatings for electrical conduits and cableterminal closures, maritime coatings, roof coatings, hydrophobic coatings on poured concrete and brickwork, paper and textile coatings, embedding of electrical and electronic devices and for fil ng ~issures and cavities. Due t~ their c~nsistency an~ sta-bility these compositions are especially suited for the coating of vertical or steep surfaces, for the filing or sealing of vertical or steep fissures and for the molding of vertical or steep planes.
Various embodiments of this invention are illustrated in the following examples in which all parts are by weight, unless otherwise specified.

A mixture containing 150 kg of a dimethylpolysiloxane having an Si-bonded hydroxyl group in each of its terminal units and which has a viscosity of 500 cP at 25C, 278 kg vinyl acetate and 1 kg of tert-butylcyclohexylpercarbonate is heated in a 2 m3 po1ymerization reactor. The mixture is stirred with an anchor stirrer for 10 hours at the rate of 50 to 100 rpm, under an ethylene pressure of 60 bar, wi-th the temperature maintained at 47C
The unreacted e~hylene ancl vinyl acetate is removed and the resultan product contains 28 percent by weight of dimethylsiloxane units, 50 percent by weight of vinyl acetate derived units and 22 percent by weight of ethylene derivecl units, based on the weight of the composition. The resultant product is a paste and is physically stable. j A mixture consisting of 187.5 gms of a diorganopoly- i siloxane having a viscosity of 620 cP at 25C and having an Si-bonded hydroxyl group in each of its terminal units, 312.5 gms of vinyl acetate and 1.5 gms of tert-butylcyclohexylpercarbonate is heated in a l-liter polymerization reactor to a temperature of 45C over a period of 22 hours, while being stirred with an anchor stirrer at 300 rpm under an ethylene pressure of 40 bar. Following removal of unreacted ethylene and vinyl acetate, a product is obtair ed which contains 33 percent by weight of dimethylpolysiloxane unit~
53 percent by weight of vinyl acetate derived units and 22 percent t weight of ethylene derived units, based on the weight of the compo-sition. The resultant product is of a paste-like consistenc~ and i~
physically stable.

A mixture consisting of 2.13 kg of a dimethylpolysiloxane having a viscosity of 420 cP at 25C and an Si~bonded hydroxyl group in each of its terminal units, 3.95 kg vinyl acetate, O.g kg of ethyl acetate and 11 grams of a mixture containing 75 percent by weight of tert-butylperpivalate and 25 percent by weight of alipha-tic hydrocarbons which are liquid at room temperature, is heated to a temperature of 55C in a 16-liter polymerization reactor over a period of 7 hours while being stirred at the rate of 100 to 300 rpm under an ethylene pressure of 60 bar. Thereafter 7 grams of tert-butylperpivalate, dissolved in 100 milliliters of ethyl acetate, are added to the poly~erization reactor and heated at 55C while being stirred at 100 to 300 rpm, for an additional 8 hours under an ethylene pressure of 60 bar. After removing the unreacted ethylene and the volatile components at 12 mm Hg (abs.), the rèsultant composition contains 27 percent by weight of dimethylpolysiloxane units, 51.2 percent by weight vinyl acetate de!rived units, and 22.8 percent by weight of ethylene derived units. The resultant paste-like product is physically stable.
EXAl'lPLE ~ !
300 grams of the product prepared in accordance wit~

~L7J;239 the procedure described i~ Example 1 are mixed under anhydrous con-ditions with 15 grams of methyltris-(cyclohexylamino)-silane. The resultant composition is physically stable and when applied as a 1 r, thick coating on a vertical surface, it cures at room temperature in atmospheric moisture to form a 1 mm thick uniform coatin~. The thickness of the coating is uniform since none of the substance mi~rated prior to curing. Elastomers made from this composition have a tensile strength of 3.5 MegaPa and an elongation of 500 per~
cent. The stability is determined in accordance with the procedure described in DIN 52,424.
EXAIlPLE 5 100 grams of the product prepared in accordance witi the procedure described in Example 1 are mixed under anhydrous conditions with 6.25 grams of methyltris-(cyclohexylamino)-silane and 25 grams of dioctyl phthalate. The resultant composition is physically stable and when exposed to atmospheric moisture at Iroom telnpera-ture, cures to an elastomeric solid having an elongatio ¦of 100 percent and a tensi?e strength of 1.8 ~legaPa. The stability is determined in accordance with the procedure described in DIN 52,424.
~ EXAMPLE 6 100 grams of the product prepared in accordance witl the precedure described in Example 1 are mixed with 3 grams of tetraethoxysilane and 0.6 gram of tin-II-octoate. The physical stability is determined in accordance with the procedure described in DIN 52,424. The composition is placed on a vertical stone surfa as a 0.5 cm thick coating. ~fter one hour, the composition cured to an elastomeric solid. It is then removed from the irregul 2 ~9 stone surface and the resultant coating is a negative pattern of the irregular stone surface.

100 grams of the product prepared in accordance with the procedure described in Example 2 are nlixed with 11.6 grams of a hydroxyl terminated dimethylpolysiloxane having a viscosity of 500 c at 25C. The resultant mixture has a viscosity of 16,000 cP at 25C
and may be pourecl due to the increase in the proportion of dimethyl-siloxane units.
COMPARISO~I EXAI~lPLE5 a) to f) a) A mixture consisting of ~.0~ kg of a hydroxyl-terminated diorganopolysiloxane, 5.2 kg of styrene, 4.2 kg of -butylacrylate, 0.8 kg of water and 0.1~1 ~g of l,l-di-tert-butyl-peroxy-3,3,5-trimethylcyclohexane is heated to 100C for 7 hours under nitrogen in a 30-liter polymerization vessel equipped with a reflux condenser and an anchor stirrer rotating at 200 rpm. After .emoving the unreacted monomers and water, the resultant liquid product contains 30 percent by weight of dimethylpolysiloxane units, 31.5 percent by weight of n-butylacrylate derived units and 38.50 ercent by weight oF styrene derived units.
b) The product prepared in accordance with Example (a) above, is mixed with 1 gram of pyrogenically produced silicon dioxide having a surface area of approximately 200 m2/9nl and 5 grams of methyltris-(cyclohexylamino)-silane. The resultant product is5 a liquid.c) The procedure described in Example (b) above is repeated, except that 2 grams of pyrogenically produced silicon dioxide having a surface area of approximately 200 m2/gm is used.

. ~ Z ~9 The resultant liquid product solidifies after storing for 2~ hours in a closed container.
d) The procedure described in Example (b) is repeated, except that 4 grams of pyrogenically produced silicon dioxide having a surface area of approximately 200 m2/gm is used. The resultant product solidifies as soon as the silicon dioxide is added e) The procedure described in Example (d) is repeated, except that 5 grams of Methyltris-(sec.-butylanlino)-silane is substituted for 5 grams of methyltris-(cyclohexylamino)-silane.
Again, solidification occurs as soon as the silicon dioxide is adde~
f) The procedure described in Example (b) is repeated, except that 10 grams of quartz ~neal is substituted for 1 gram of the pyrogenically produced silicon dioxide. The resultant mixture is a quid.

. ,1 .

Claims (13)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A composition containing a diorganopolysiloxane and a copoly-mer derived from monomers consisting of at least ethylene and vinyl acetate in which the copolymer consists of from 30 to 40 percent by weight of units derived from ethylene, from 57.5 to 70 percent by weight of units derived from vinyl acetate and from 0 to 3.5 percent by weight of units derived from a monomer other than ethylene and vinyl acetate which is capable of being polymerized in the presence of a free radical initiator, said copolymer hav-ing been prepared in the presence of the diorganopolysiloxane and being present in the composition in an amount of from 65 to 85 percent by weight based on the weight of the copolymer and the diorganopolysiloxane.

2. The composition of claim 1, wherein the diorganopolysiloxane is represented by the formula:
Zn SiR3-n0(siR20)xSiR3-nzn in which R is selected from the class consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radi-cals, Z is selected from the class consisting of hydroxyl groups, hydrolyza-ble groups and hydrolyzable atoms, n is 0, 1, 2 or 3 and x is 0 or an inte-ger of at least 1.

3. The composition of claim 2 , wherein Z represents a hydrolyza-ble group.

4. The composition of claim 3, wherein Z is selected from the class consisting of acyloxy, hydrocarbonoxy, substituted hydrocarbonoxy, hydrocarbonoxy-hydrocarbonoxy, aminoxy; amino, acylamino, oxime and phos-phate groups.

5. The composition of claim 2 wherein Z represents hydroxyl groups.

6. The composition of claim 2 wherein one of the R radicals on each of the terminal silicon atoms is a vinyl group and n is 0.

7. A room temperature curable composition which is stored under anhydrous conditions and, which when exposed to atmospheric moisture, cures to an elastomeric solid, comprising (a) the composition of claim 1 and (b) a silicon compound having at least three hydrolyzable groups per molecule.

8. The composition of claim 7, wherein said composition also contains (c) a condensation catalyst.

9. A room temperature curable composition comprising: (a) the composition of claim 1, (b) a crosslinking agent selected from the class consisting of silanes of the formula Rn,Si(OZ')4-n' and siloxanes, said silanes being liquid at room temperature and contain at least three SiOZ' groups and the remaining silicon atoms on the siloxanes which are not linked to siloxane oxygen atoms, OZ' groups or hydrogen atoms are satisfied by R groups and (c) a condensation catalyst, in which R is selected from the class consisting of monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals and cyanoalkyl radicals, Z' is selected from the class consisting of a hydrocarbon radical and a hydro-carbon radical containing an ether oxygen atom and n' is 0 or 1.

10. A curable composition comprising: (a) the composition of claim 6; (b) an organopolysiloxane which contains at least three Si-bonded hydro-gen atoms per molecule; and (c) a catalyst which promotes the addition of Si-bonded hydrogen to the vinyl groups.

11. The composition of claim 10, wherein the organopolysiloxane containing at least three Si-bonded hydrogen atoms per molecule is present in an amount of from 0.5 to 20 percent by weight based on the weight of the organopolysiloxanes.

12. A process for preparing the composition of claim 1 which com-prises: polymerizing at a temperature of from 30 to 70°C,at least two mono-mers having aliphatic unsaturation consisting of ethylene and vinyl acetate in the presence of a diorganopolysiloxane and free radical initiators, in which vinyl acetate is present in an amount of from 50 to 75 percent by weight based on the weight of vinyl acetate and diorganopolysiloxane and the total volume of vinyl acetate and diorganopolysiloxane does not exceed 60 percent of the volume of the polymerization device and the ethylene is present at a pressure of from 40 to 70 bar.

13. The process of claim 12, wherein monomers other than ethylene and vinyl acetate which are capable of being polymerized in the presence of free radical initiators are present in an amount of up to 5 percent by weight based on the weight of the vinyl acetate.