Alkenyl ether functional polyisbutylenes and methods for the preparation thereof

Abstract: This invention provides alkenyl ether functional polyisobutylenes and said method comprises reacting a mixture comprising an alkoxysilyl-functional polyisobutylene polymer, an alkenyl ether compound and a transesterification catalyst. This invention also discloses a method of making an alkenyl ether functional polyisobutylene polymer comprising reacting a mixture comprising a polyisobutylene containing at least one hydrolyzable group, an alkenyl ether compound and a solvent. The alkenyl ether functional polyisobutylenes of this invention have high moisture vapor barrier, high damping characteristics and a high refractive index.

Description: Our invention provides alkenyl ether functional polyisobutylene polymers and methods of making alkenyl ether functional polyisobutylene polymers. Our polyisobutylenes are useful in curable compositions in the form of coatings, sealants, caulks, adhesives and paints. Polyisobutylenes (PIB) containing functional groups which are radiation curable have been disclosed in the art. For example, T. P. Liao and J. P. Kennedy in Polymer Bulletin, V. 6 , pp. 135-141 (1981) disclose acryl and methacryl telechelic polyisobutylenes having the formula CH 2 =C(R)-COO-PIB-OOC-C(R)=CH 2 where R is -H or CH 3 . These materials were prepared by reacting alpha, omega dihydroxypolyisobutylene, HOCH 2 -PIB-CH 2 OH and excess acryloyl or methacryloyl chloride. These prepolymers are useful in the synthesis of a variety of new composites containing a soft polyisobutylene segment. J. P. Kennedy and B. Ivan in Polymer Material Science and Engineering, V. 58 , p.866 (1988) disclose allyl telechelic linear and star-branched polyisobutylenes prepared by a convenient rapid one pot polymerization functionalization process. The polymerization step involved living polymerization of isobutylene by recently discovered mono- or multifunctional initiating systems followed by electrophilic functionalizations by allyltrimethylsilane in the presence of TiCl 4 . Characterization indicated quantitative end allylations. Subsequent quantitative derivations of the allyl termini yielded mono-, di- and tri-functional hydroxyl- and epoxy-telechelic polyisobutylenes which could be cured to rubbery networks. J. P. Kennedy and B. Ivan in the Journal of Polymer Science, Part A, Polymer Chemistry, V. 28 , p. 89 (1990) disclose mono-, di-ended linear and three-arm star allyl telechelic polyisobutylenes which are prepared by a rapid economical one-pot polymerization-functionalization process. The process involved the living polymerization of isobutylene by mono-, di- or tri-functional initiating systems, specifically by aliphatic and aromatic tert-ester and -ether/TiCl 4 combinations, followed by electrophilic functionalization of the living sites with allyltrimethylsilane. Quantitative derivations of the allyl termini yielded mono-, di- and tri-epoxy and -hydroxy-telechelic polyisobutylenes. Strong rubbery networks were made by curing the epoxy-telechelic polyisobutylenes with triethylene tetramine and by reacting the hydroxy-telechelic polyisobutylenes with MDI. N.A. Merrill, I.J. Gardner and V.L. Hughes in RadTech North America Proceedings, V. 1 , pp. 77-85 (1992) disclose conjugated diene functional polyisobutylenes which have a high reactivity to both ultraviolet and electron beam radiation. These conjugated diene functional polyisobutylenes, alone or in a formulation, are disclosed as being useful in preparing pressure sensitive adhesives. In PCT Publication WO 9104992 is disclosed a functionalized copolymer of isobutylene and a para-methylstyrene, wherein at least one type of functional group is attached to the para-methyl group of the para-methylstyrene, the copolymer having a substantially homogenous compositional distribution. The functionalized groups are exemplified by alkoxides, phenoxides, carboxylates, thiolates, thiopenolates, thioethers, thiocarboxylates, dithiocarboxylates, thioureas, dithiocarbamates, xanthanates, thiocyanates, silanes, halosilanes, malonates, cyanides, amides, amines, carbazoles, phthalimides, pyridine, maleimide, cyanates and phosphines. In PCT Publication WO 9211295 is disclosed a radiation reactive functionalized polymer comprising an isoolefin having 4 to 7 carbon atoms and a para-alkylstyrene, wherein a radiation reactive functional group is attached to the para-alkyl group of the para-alkylstyrene and discloses radiation curable pressure sensitive adhesives comprising the functionalized polymer and a tackifier. The radiation curable groups are disclosed as being groups such as thioxanthones, acrylates, aldehydes, ketones and esters. U.S. Patent 5,665,823 discloses a method for preparing an acrylic functional polyisobutylene polymer or copolymer, the method comprising reacting a polyisobutylene polymer or copolymer which contains at least one carbon-bonded silanol group in its molecule with a silane having both an acrylic-containing group and a silicon-bonded hydrolyzable group in its molecule. Furthermore, radiation curable compositions which contain alkenyl ether functional organosilicon compounds have also been described in the art. For example, U.S. Patent 4,617,238 discloses a photopolymerizable composition comprising (a) an organopolysiloxane having at least one Si-bonded vinyloxy functional group of the formula H 2 C=CH-O-G-, where G is alkylene (such as propylene) or alkylene interrupted by at least one divalent heteroradical selected from -O-, divalent phenylene or substituted divalent phenylene or combination of such heteroradicals and (b) an onium salt catalyst. The '238 patent also describes a method wherein the vinyl ether group is introduced into the organopolysiloxane by addition (hydrosilylation) of compounds with an allyl and a vinyl ether group to an SiH group of the organopolysiloxane in the presence of a platinum catalyst. Only the allyl group is added to the SiH group in this method, while the vinyl ether group is preserved and thus only one vinyl ether group for each SiH group can be incorporated into the siloxane molecule at any given time. European Patent Publication 0462389 teaches thermosetting organopolysiloxanes with oxyalkylene vinyl ether groups bonded by SiOC groups and the vinyl groups may be substituted by alkyl groups. A method for the preparation of these compounds is also taught and their application as photochemically thermosetting polysiloxanes in encapsulating compounds, as non-stick coating compounds for flat carriers or as modified additives in compounds which can be thermoset radically, cationically or by UV or electron radiation. U.S. Patent 5,270,423 discloses organosilicon compounds with a siloxane portion of the general formula -OR'OCH=CHR" linked via an SiOC bond wherein R' is a divalent hydrocarbon group and R" is hydrogen or an alkyl group which are useful in radiation curable compositions, in which they are mixed with an initiator. The compositions are particularly useful in UV radiation curable coatings. U.S. Patent 5,594,042 discloses radiation curable compositions comprising vinyl ether functional siloxanes and aromatic iodonium salt or aromatic sulfonium salt photoinitiators which cure upon exposure to ultraviolet or electron beam radiation. The vinyl ether groups are linked to the silicon atom on the siloxane through an SiOC bond and the photoinitiators are disclosed as being preferably either diaryliodonium salts of sulfonic acids or triarylsulfonium salts of sulfonic acids. U.S. Patent 5,629,095 discloses vinyl ether functional siloxane resins, radiation curable coating compositions comprising a vinyl ether functional siloxane resin and a photocleavable acid and a coated article obtained by applying the radiation curable coating composition to a substrate and then exposing the coating to radiation in an amount sufficient to cure the coating. The vinyl ether group in the siloxane resin is attached to the silicone atom through an SiOC bond. Our present invention provides alkenyl ether functional polyisobutylenes and a method of making alkenyl ether functional polyisobutylene polymers in which at least 50 mole percent of the repeat units are isobutylene units comprising reacting a mixture comprising an alkoxysilyl-functional polyisobutylene polymer, an alkenyl ether compound and a transesterification catalyst. This invention also provides a method of making an alkenyl ether functional polyisobutylene polymer in which at least 50 mole percent of the repeat units are isobutylene units comprising reacting a mixture comprising a polyisobutylene containing at least one silicon-bonded hydrolyzable group, an alkenyl ether compound and a solvent. It is an object of this invention to produce alkenyl ether functional polyisobutylenes which are useful in radiation curable coatings having high moisture vapor barrier, high damping characteristics and a high refractive index. In a first embodiment, this invention provides an alkenyl ether-functional polyisobutylene polymer in which at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units and containing at least one group having the formula wherein R is independently selected from monovalent hydrocarbon groups or alkoxy groups, R 1 is a divalent hydrocarbon group having from 2 to 20 carbon atoms, R 2 and R 3 are independently selected from hydrogen atom or a monovalent hydrocarbon group and a has a value of 0 to 2. The monovalent hydrocarbon groups of R are exemplified by alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, octyl and decyl, aryl groups such as phenyl, tolyl and xylyl and can also be any monovalent hydrocarbon group which has at least one of its hydrogen atoms replaced with a halogen atom, such as fluorine, chlorine or bromine. These monovalent hydrocarbon groups are exemplified by CF 3 CH 2 CH 2 - and C 4 F 9 CH 2 CH 2 -. The alkoxy groups are exemplified by methoxy, ethoxy, propoxy and butoxy. Preferably, R is independently selected from methyl or methoxy. Each R group can be the same or different, as desired. Divalent hydrocarbon groups suitable as R 1 are exemplified by alkylene groups such as ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene, decamethylene, -(CH 2 ) 18 - and cycloalkylene groups such as cyclohexylene, arylene groups such as phenylene, combinations of divalent hydrocarbon groups such as benzylene. Examples of suitable divalent halohydrocarbon groups also include any divalent hydrocarbon group wherein one or more hydrogen atoms have been replaced by halogen, such as fluorine, chlorine or bromine exemplified by -CH 2 CH 2 CF 2 CF 2 CH 2 CH 2 -. Each R 1 can be the same or different as desired. Preferably R 1 is butylene. The groups R 2 and R 3 may be either a hydrogen atom or a monovalent hydrocarbon group exemplified by alkyl groups such as methyl, ethyl, propyl butyl. The groups R 2 and R 3 may be the same or different. Preferably, R 2 and R 3 are hydrogen atoms. In the formula above, it is preferred that a have a value of zero. For the purposes of this invention, the backbone of the alkenyl ether functional polyisobutylene polymer may be any linear or branched polymer or copolymer wherein at least about 50 mole percent, preferably at least 80 mole percent, of the repeat units are isobutylene units having the following structure: In the polymer or copolymer of the invention, the above described alkenyl ether group can be disposed either along the chain or at the terminals thereof or any combination of the above. As used herein, the term "polymer" is generic to polymers, oligomers and copolymers, all of which are within the scope of this invention. In a preferred embodiment, the alkenyl ether functional polyisobutylene polymer is a polymer containing at least one group having the formula wherein at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, R is independently selected from monovalent hydrocarbon groups or alkoxy groups, R 1 is a divalent hydrocarbon group having from 2 to 20 carbon atoms, R 2 and R 3 are independently selected from a hydrogen atom or a monovalent hydrocarbon group, n has a value from 5 to 10,000, a has a value of 0 to 2 and Y is selected from (i) an alkylene group having from 2 to 10 carbon atoms or (ii) a group having the formula wherein R 4 is independently a monovalent hydrocarbon group, R 5 and R 6 are independently alkylene groups having from 2 to 10 carbon atoms and m is an integer having a value of from 1 to 5. The groups R and R 1 are as defined hereinabove, including preferred embodiments thereof. Preferably, R is independently selected from methyl or methoxy and R 1 is butylene. Preferably, a has a value of 0 or 1. The alkylene groups of Y(i) are exemplified by ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene and decamethylene. In the formula for Y(ii) above, the monovalent hydrocarbon groups of R 4 are as described above for R, and preferably R 4 is methyl. The alkylene groups for R 5 and R 6 are as defined above for Y(i). Preferably, R 5 and R 6 are independently selected from ethylene or propylene. It is highly preferred that R 5 is propylene and R 6 is ethylene. It is also preferred that m has a value of 1. In a second embodiment, our invention teaches a method of making an alkenyl ether functional polyisobutylene polymer in which at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, the method comprising (I) reacting a mixture comprising: (A) a polyisobutylene polymer containing at least one group having the formula wherein at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, R 7 is an alkyl group having from 1 to 5 carbon atoms, R is independently a monovalent hydrocarbon group, a has a value of 0 to 2 and Z is selected from (i) an alkylene group having from 2 to 10 carbon atoms or (ii) a group having the formula wherein R 4 is independently a monovalent hydrocarbon group, R 5 and R 6 are independently alkylene groups having from 2 to 10 carbon atoms and m is an integer having a value of from 1 to 5, (B) an alkenyl ether compound having the formula HOR 1 OC(R 2 )=CH(R 3 ) wherein R 1 is a divalent hydrocarbon or halohydrocarbon group having from 2 to 20 carbon atoms, R 2 and R 3 are independently selected from a hydrogen atom or a monovalent hydrocarbon group, and (C) a transesterification catalyst. The reaction mixture can further comprise a nonpolar solvent. The reaction mixture can also further comprise an alkoxysilane. The method can further comprise removing volatiles from the product of (I). Reacting for the purposes of this invention denotes mixing components (A), (B) and (C), and any optional components at room temperature (25°C.) or heating a mixture of components (A)-(C) and any optional components at temperatures above room temperature. Preferably, a mixture of components (A)-(C) and any optional components are heated at a temperature of 40 to 150°C. The monovalent hydrocarbon groups for R 4 are as described hereinabove including preferred embodiments thereof. Preferably R 4 is methyl. The alkylene groups for R 5 and R 6 are as described hereinabove including preferred embodiments thereof. Preferably, R 5 and R 6 is selected from ethylene or propylene. It is highly preferred that R 5 is propylene and R 6 is ethylene. The group R 7 in the above formula for (A) is exemplified by methyl, ethyl, propyl, butyl and pentyl. Preferably, R 7 is methyl. It is preferred that m have a value of 1. Preferably, the polyisobutylene polymer of component (A) has a number average molecular weight of from 500 to 100,000, and especially from 1,000 to 20,000 based on their ease of handling. The polyisobutylene polymers of component (A) and their method of preparation are disclosed in U.S. Patents 4,808,664 and 4,904,732 to teach polyisobutylene polymers suitable as component (A) and the method for their preparation. Preferably, the polyisobutylene polymer of component (A) is a polymer containing at least one group having the formula wherein R is independently a monovalent hydrocarbon group, R 7 is an alkyl group having from 1 to 5 carbon atoms, n has a value from 10 to 2,000, a has a value of 0 to 2 and Z is selected from (i) an alkylene group having from 2 to 10 carbon atoms or (ii) a group having the formula wherein R 4 is independently a monovalent hydrocarbon group, R 5 and R 6 are independently alkylene groups having from 2 to 10 carbon atoms and m is an integer having a value of from 1 to 5. The monovalent hydrocarbon groups of R and R 4 are as defined hereinabove, including preferred embodiments thereof. Preferably, R and R 4 are methyl. The alkyl groups of R 7 are as defined above, preferably R 7 is methyl. The alkylene groups of Z(i) are exemplified by ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene and decamethylene. The alkylene groups for R 5 and R 6 are as defined above for Z(i). Preferably, R 5 and R 6 are independently selected from ethylene or propylene. It is highly preferred that R 5 is propylene and R 6 is ethylene. It is also preferred that m has a value of 1 and a has a value of 0. It is preferred for the purpose of this invention, that the number of moles of component(B) is equal to or as close as possible to the number of moles of the Si(OR 7 ) functional group in component A. Component (B) is an alkenyl ether compound having the formula HOR 1 OC(R 2 )=CH(R 3 ) wherein R 1 is a divalent hydrocarbon or halohydrocarbon group having from 2 to 20 carbon atoms. Divalent hydrocarbon groups suitable as R 1 are exemplified by alkylene groups such as ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene, -(CH 2 ) 18 - and cycloalkylene groups such as cyclohexylene, arylene groups such as phenylene, combinations of divalent hydrocarbon groups such as benzylene. Examples of suitable divalent halohydrocarbon groups also include any divalent hydrocarbon group wherein one or more hydrogen atoms have been replaced by halogen, such as fluorine, chlorine or bromine exemplified by -CH 2 CH 2 CF 2 CF 2 CH 2 CH 2 -. Each R 1 can be the same or different as desired. Preferably R 1 is butylene. The groups R 2 and R 3 may be either a hydrogen atom or a monovalent hydrocarbon group exemplified by alkyl groups such as methyl, ethyl, propyl or butyl. The groups R 2 and R 3 may be the same or different. Preferably, R 2 and R 3 are hydrogen atoms. It is preferred for the purposes of this invention that the number of moles of alkenyl ether groups be equal to the number of moles of the Si(OR 7 ) functional groups, that is the number of moles of component (B) is equal to or as close as possible to the number of moles of the Si(OR 7 ) functional groups. Component (C), the transesterification catalyst, is exemplified by alkali metal alkoxides, Sn compounds, Ti compounds, Zn compounds, Ba compounds, as well as standard strong alkali compounds. Strong acid compounds are to be avoided as they tend to polymerize oxyalkenyl groups. Examples of suitable transesterification catalysts include dimethyltin neodecanoate, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctoate, zinc napthenate, cobalt napthenate, zinc octylate, tin octylate, cobalt octylate, diisooctyl mercaptoacetate, zirconium napthenate, zirconium octylate, tetrabutyl titanate, tetraisopropyl titanate, barium hydroxide monohydrate and other organic metal catalysts. It is preferred for the purposes of this invention that the transesterification catalyst be selected from alkoxides such as tetraisopropyl titanate, barium hydroxide monohydrate and sodium methoxide. The amount of transesterification catalyst needed for the method of the present invention will be determined by the skilled artisan through routine experimentation. Typically, this component is employed at a level of from 50 parts per million (ppm) to 100,000 ppm, preferably from 50 ppm to 1000 ppm. The mixture of step (I) can further comprise a nonpolar solvent. The nonpolar solvent is exemplified by aliphatic hydrocarbons such as pentane, cyclopentane, hexane, cyclohexane, heptane, octane and nonane, aromatic hydrocarbons such as benzene, toluene and xylene; and halogenated solvents such as fluorine-, chlorine- and bromine-substituted aliphatic or aromatic hydrocarbons such as perchloroethylene and bromobenzene. Two or more nonpolar solvents may be used together. The amount of nonpolar solvent is not critical and may be readily determined by one skilled in the art. The compositions of this invention may contain up to 0-100 parts by weight of the nonpolar solvent per 100 parts by weight of the polymer, however, it is preferred that from 50 to 100 parts by weight be employed per 100 parts by weight of the polymer. The method of this invention can further comprise removing volatiles from the product of (I). Methods of removing volatile components are well-known in the art. Any method of removing volatile components can be used in the present invention, such methods exemplified by heating, heating and applying a vacuum, rotoevaporators, thin film strippers, wiped film evaporators or a combination thereof. Preferably, the volatiles are removed by heating the product of (I) to a temperature of from 50 to 150°C. under a vacuum of approximately 20-100 Torr (0.027 - 0.13 bars). In a third embodiment, this invention provides a method of making an alkenyl ether functional polyisobutylene polymer in which at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, the method comprising (I) reacting a mixture comprising: (A') a polyisobutylene polymer containing at least one group having the formula wherein at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, X is a hydrolyzable group selected from a halogen atom, an acyloxy group, a ketoxymate group, an amino group, an amido group or an aminoxy group, R is independently a monovalent hydrocarbon group, b has a value of 0 to 2 and W is selected from (i) an alkylene group having from 2 to 10 carbon atoms or (ii) a group having the formula where R 4 is a monovalent hydrocarbon group, R 5 and R 6 are independently alkylene groups having from 2 to 10 carbon atoms and m is an integer having a value of from 1 to 5, (B') an alkenyl ether compound having the formula HOR 1 OC(R 2 )=CH(R 3 ) wherein R 1 is a divalent hydrocarbon or halohydrocarbon group having from 2 to 20 carbon atoms, R 2 and R 3 are independently selected from a hydrogen atom or a monovalent hydrocarbon group and (C') a solvent. The reaction mixture can further comprise a base to consume any acidic by products generated during the reaction. The hydrolyzable group X can be a halogen atom exemplified by fluorine, chlorine and bromine, an acyloxy group, a ketoxymate group, an amino group, an amido group and an aminoxy group. Preferably X is chlorine. Preferably b has a value of 0. The monovalent hydrocarbon groups for R and R 4 are as described hereinabove including preferred embodiments thereof. Preferably R and R 4 are methyl. The alkylene groups of W(i) are exemplified by ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene and decamethylene. The alkylene groups for R 5 and R 6 are as defined above for W(i). Preferably R 5 and R 6 are selected from ethylene or propylene. It is highly preferred that R 5 is propylene and R 6 is ethylene. It is preferred that m have a value of 1. Preferably, the polyisobutylene polymer of component (A') has a number average molecular weight of from 500 to 100,000, and especially from 1,000 to 20,000 based on their ease of handling. Preferably, the polyisobutylene polymer of component (A') is a compound containing at least one group having the formula wherein n has a value from 10 to 2,000, X is a hydrolyzable group selected from halogen atom, an acyloxy group, a ketoxymate group, an amino group, an amido group and an aminoxy group, R is independently a monovalent hydrocarbon group, b has a value of 0 to 2 and W is selected from (i) an alkylene group having from 2 to 10 carbon atoms or (ii) a group having the formula where R 4 is a monovalent hydrocarbon group, R 5 and R 6 are independently alkylene groups having from 2 to 10 carbon atoms and m is an integer having a value of from 1 to 5. Preferably X is chlorine, R is methyl, b has a value of 0, W(i) is selected from ethylene, propylene, butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene or decamethylene. Preferably R 4 is methyl. The alkylene groups for R 5 and R 6 are as defined above for W(i). Preferably, R 5 and R 6 are selected from ethylene or propylene. It is highly preferred that R 5 is propylene and R 6 is ethylene. It is preferred that m have a value of 1. Component (B'), the alkenyl ether compound, is as described hereinabove in the second embodiment of this invention including preferred embodiments thereof. Preferably R 1 is butylene and R 2 and R 3 are hydrogen atoms. Component (C') the solvent can be either a non-polar solvent or a polar solvent. The non-polar solvent is as described above in the second embodiment of this invention including preferred embodiments thereof. The polar solvent is exemplified by chloromethane, methylene chloride and mixtures thereof. The amount of solvent is not critical and may be readily determined by one skilled in the art. The compositions of this invention may contain up to 200 parts by weight of solvent per 100 parts by weight of Component (A'); however, it is preferred that from 50 to 100 parts by weight be employed per 100 parts by weight of Component (A') be used. The reaction mixture can further comprise a base exemplif ied by amines such as pyridine, triethylamine, tri-n-butylamine and dodecyl amine. It is preferred for purposes of this invention that the number of moles of the alkenyl ether compound, Component (B'), described above be equal to or slightly larger than the number of moles of Si-X groups in the polyisobutylene polymer (A'). The polyisobutylenes of this invention find utility as components in curable compositions in the form of coatings, sealants, caulks, adhesives and paints. These compositions can be applied to various substrates such as glass, metal cloth, fabric, paper, plastic and masonary. The curable compositions are preferably cured in form of films. The cured films are expected to have high refractive index, good barrier properties, good adhesion and good damping properties. It is preferable to apply these coatings to surfaces that are adversely affected by exposure to oxygen, moisture vapor and other environmental factors. The alkenyl ether functional polyisobutylenes are particularly useful as components in high refractive index coatings for optical fibers. The application of the radiation curable compositions containing the polyisobutylenes of this invention to optical fibers and curing of the compositions can be achieved by conventional equipment (see Blyler and Aloisio, Polymers for coating optical fibers, Chemtech, Nov. 1987, pages 680-684). The curable compositions can also be used as an additive to compositions for improving barrier properties to higher values. The radiation curable compositions can used to increase the barrier properties of sealants and pottants used for encapsulating electronic devices that are adversely affected by moisture. Materials: The allyl functional polyisobutylene (PIB) polymer was made by Kaneka Corporation and is called Epion™ 200A polymer. Hydroxybutyl vinyl ether, 1-dodecene, methyltrichlorosilane and methyldichlorosilane was purchased from Aldrich Chemical Company, as were other solvents and common reagents used in the examples. The platinum (vinylsiloxane) catalyst were prepared by the procedure of Hitchcock et. al., Angew. Chem. Int. Ed. Engl. 1991, 30. 13 C NMR and 29 Si NMR (nuclear magnetic resonance) spectroscopy was used to confirm the structures. The molecular weight of each polyisobutylene was determined by gel permeation chromatography (GPC) using standard PIB samples for molecular weight calibration. In the examples hereinbelow, M n denotes number average molecular weight and M w denotes weight average molecular weight. Example 1 The methoxysilyl-functional polyisobutylene polymers were prepared per the procedure disclosed by Saam et. al. in Example 2 of U.S. Patent 4,808,664, except that the starting polyisobutylene polymer was the commercially available Epion™ 200A (an allyl telechelic polyisobutylene made by Kaneka Corporation, Tokyo, Japan). Example 2 A mixture of 1112 g of the polymer from Example 1 and 1500 ml of cyclohexane was added to a round bottom flask, equipped with mechanical stirrer, Dean-Stark separator and reflux condenser. To the flask was added 140 grams of 4-hydroxybutyl vinyl ether (HO(CH 2 ) 4 OCH=CH 2 ) and 0.5 ml of tetraisopropyl titanate. The reaction mixture was heated at a temperature of 70°C. with stirring for eight hours, during which time approximately 35 ml of methanol was removed from the Dean-Stark separator. 1 H NMR spectrum of a small sample confirmed that the product had the following structure: (Note: PIB denotes the initial polyisobutylene polymer) The cyclohexane solvent was removed by thin film stripper. Molecular weight data: M n = 6800; M w 10400; M w /M n = 1.52. Example 3 Fifty grams of Epion™ 200A was dissolved in 150 ml of heptane. Platinum (vinylsiloxane) catalyst was added to the mixture at a molar ratio of 1x10 -4 equivalents/allyl group and 1.10 (equivalents per allyl group)) of trichlorosilane was added dropwise to the reaction mixture. The reaction mixture was maintained for eight hours at 70°C. 1 H NMR spectra confirmed the absence of allyl resonance. After cooling to room temperature, 40 ml of methylene chloride was added to the flask followed by 15 g of triethylamine. Thereafter, 15 ml of 4-hydroxybutyl vinyl ether was added dropwise from an addition funnel to the flask, and after addition, the contents were allowed to stir overnight. The precipitated salts were filtered off. The polymer was isolated by precipitation into methanol and dried. 1 H NMR spectra of the product confirms the following structure: Molecular Weight data: M n = 7528, M w = 35420; M w /M n = 4.70.

Claims: An alkenyl ether-functional polyisobutylene polymer in which at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units and containing at least one group having the formula wherein R is independently selected from monovalent hydrocarbon groups and alkoxy groups, R 1 is a divalent hydrocarbon group having from 2 to 20 carbon atoms, R 2 and R 3 are independently selected from a hydrogen atom and monovalent hydrocarbon groups and a has a value of 0 to 2. A polymer according to claim 1, wherein R is independently selected from methyl and methoxy, R 1 is butylene, R 2 and R 3 are each hydrogen atoms and a has a value of zero. A polymer according to claim 1 wherein the alkenyl ether functional polyisobutylene polymer is a polymer containing at least one group having the formula wherein at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, wherein R, R 1 , R 2 , R 3 and a are as defined in claim 1, n has a value from 5 to 10,000 and Y is selected from (i) an alkylene group having from 2 to 10 carbon atoms and (ii) a group having the formula wherein R 4 is independently a monovalent hydrocarbon group, R 5 and R 6 are independently alkylene groups having from 2 to 10 carbon atoms and m is an integer having a value of from 1 to 5. A polymer according to claim 3 wherein R is independently selected from methyl and methoxy, R 1 is butylene, a has a value of 0 or 1, R 2 and R 3 are hydrogen atoms, and Y(i) is ethylene, propylene butylene, pentylene, trimethylene, 2-methyltrimethylene, pentamethylene, hexamethylene, 3-ethyl-hexamethylene, octamethylene or decamethylene. A polymer according to claim 3,wherein R is independently selected from methyl and methoxy, R 1 is butylene, a has a value of 0 or 1, R 4 is methyl, R 5 is propylene, R 6 is ethylene and m has a value of 1. A method of making an alkenyl ether functional polyisobutylene polymer in which at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, the method comprising (I) reacting a mixture comprising: (A) a polyisobutylene polymer containing at least one group having the formula wherein at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, R 7 is an alkyl group having from 1 to 5 carbon atoms, R and a are as defined in claim 1 and Z is selected from (i) an alkylene group having from 2 to 10 carbon atoms and (ii) a group having the formula wherein R 4 , R 5 , R 6 and m are as defined in claim 3; (B) an alkenyl ether compound having the formula HOR 1 OC(R 2 )=CH(R 3 ) wherein R 1 , R 2 and R 3 are as defined in claim 1; and (C) a transesterification catalyst. A method according to claim 6 wherein (A) is a polymer containing at least one group having the formula wherein R and a are as defined in claim 1, R 7 and Z are as defined in claim 6 and n has a value from 10 to 2,000. A method according to claim 6 or 7, wherein the mixture of step (I) further comprises a nonpolar solvent selected from pentane, cyclopentane, hexane, cyclohexane, heptane, octane, nonane, benzene, toluene, xylene, perchloroethylene and bromobenzene. A method according to any of claims 6 to 8, wherein the method further comprises removing volatiles from the product of (I). A method of making an alkenyl ether functional polyisobutylene polymer in which at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, the method comprising: (I) reacting a mixture comprising: (A') a polyisobutylene polymer containing at least one group having the formula wherein at least 50 mole percent of the non-terminal repeating units of the polymer are isobutylene units, X is a hydrolyzable group selected from a halogen group, an acyloxy group, a ketoxymate group, an amino group, an amido group an an aminoxy group, R is as defined in claim 1, b has a value of 0 to 2 and W is selected from (i) an alkylene group having from 2 to 10 carbon atoms and (ii) a group having the formula wherein R 4 , R 5 , R 6 and m are as defined in claim 3; (B') an alkenyl ether compound having the formula HOR 1 OC(R 2 )=CH(R 3 ) wherein R 1 , R 2 and R 3 are as defined in claim 1; and (C') a solvent. A method according to claim 10 wherein component (A') is a polymer containing at least one group having the formula wherein n is as defined in claim 3, X is a hydrolyzable group selected from a halogen atom, an acyloxy group, a ketoxymate group, an amino group, an amido group and an aminoxy group, R is as defined in claim 1, and b and W are as defined in claim 10. A method according to claim 10 or 11, wherein the mixture of (I) further comprises a base selected from pyridine, triethylamine, tri-n-butylamine and dodecyl amine.

Inventors: BAHADUR MANEESH, SUZUKI TOSHIO, BAHADUR, MANEESH, SUZUKI, TOSHIO
Applicants: DOW CORNING, DOW CORNING CORPORATION
Application year: 1999
Main classification: C08F8
IPC codes: C09J123, C09J4, C08F10, C09D4, C08F8, C09D123, C08F110