Abstract: The present invention provides a high temperature continuous polymerization and condensation process for preparing a polymeric product. The process includes continuously charging into a reaction zone: at least one radically-polymerizable monomer having a radically polymerizable group and at least one condensation reactive functionality; and at least one modifying agent having a functional group capable of reacting with the condensation reactive functionality. The reaction zone includes at least one primary reactor, but may, and preferably does, contain a secondary reactor. The process further includes maintaining an effective temperature in the primary reactor to cause polymerization of the monomer and to allow at least a portion of the condensation reactive functionality to react with the functional group of the modifying agent.

Abstract: In a process for the anionic polymerization of vinylaromatic monomers or dienes in the presence of a lithium organyl or lithium alcoholate and a magnesium and/or an aluminum compound, a sterically hindered phenol or amine is added.

Abstract: It has been discovered that the polymerization of diene compounds, such as butadiene, may be inhibited by the addition of a composition that contains at least one hindered or unhindered phenol, in combination with low nitrogen content component which is a stable nitroxide and/or a hydroxylamine substituted with at least one alkyl, aryl or alkylaryl group; and/or a second, different hindered or unhindered phenol, and optionally a hydrogen transfer agent.

Abstract: A liquid phase polymerization process for preparing low molecular weight, highly reactive polyisobutylene. The process includes the steps of providing a feedstock containing isobutylene and a catalyst composition made up of a complex of BF3 and a complexing agent. The feedstock and the catalyst composition are introduced into a residual reaction mixture in a reaction zone where the residual reaction mixture, the feedstock and the catalyst composition are intimately intermixed so as to present an intimately intermixed reaction admixture in said reaction zone. The intimately intermixed reaction admixture is maintained in its intimately intermixed condition and kept at a temperature of at least about 0° C. while the same is in the reaction zone, whereby the isobutylene therein is polymerized to form polyisobutylene having a high degree of terminal unsaturation. A product stream is withdrawn from the reaction zone.

Abstract: A process for polymerization of vinyl monomers is described comprising polymerizing vinyl monomers in the presence of an initiating system comprising (i) an organic iodide, organic bromide, organic chloride, or an organic sulfur initiator compound, and (ii) a layered material catalyst, and wherein when the initiator compound comprises an organic bromide or organic chloride compound, the initiating system further comprises an iodide or sulfur containing salt compound or a transition metal salt. The present invention provides a novel method for living polymerization of vinyl monomers, which provides a high level of macromolecular control over the polymerization process and which leads to uniform and controllable polymeric products, which may include well-defined structures and complex architectures.

Abstract: A process for the continuous preparation of polyisobutene having a number-average molecular weight {overscore (M)}N of from 500 to 50,000 and containing at least 50 mol % of terminal double bonds by one-stage or multistage, continuous polymerization of isobutene in the liquid phase in the presence of a catalyst comprising boron trifluoride and at least one oxygen-containing compound at below +40° C., wherein the liquid reaction phase has a viscosity of from 6 to 20 mm2/s (determined according to DIN 51562), at least in the first polymerization stage, is described.

Abstract: A cationically polymerizable composition is provided, which comprises a cationically polymerizable compound, a cationic polymerization initiator, and a specific tertiary alkanolamine or tertiary alkylamine. The cationically polymerizable compound is preferably an alicyclic epoxy compound and an oxetane compound. The above amine accounts for 0.01 to 1.0% by weight, preferably 0.05 to 0.5% by weight of the total of the cationically polymerizable composition and the cationic polymerization initiator accounts for 0.1 to 20 parts by weight based on 100 parts by weight of the cationically polymerizable compound. The composition is excellent in storage stability and dispersion stability of colorants contained therein.

Abstract: The invention concerns a method for preparing a first generation polymer comprising a step which consists in radical polymerization of a composition containing: at least an ethylenically unsaturated monomer a free radical source, and at least a disulfide compound.

Abstract: The invention relates to a new improved catalyst to produce random copolymers of one or more iso-olefin monomers and one or more para-alkylstyrene monomers. The invention also relates to an improved continuous slurry polymerization process to produce random copolymers using the improved catalyst system. The process is carried out in an anhydrous polymerization system containing a mixture of the monomers in a polar solvent along with a Lewis acid and a stabilizing initiator.

Abstract: The present invention provides a polymer obtained by polymerizing a mixture composed of a methacrylic ester monomer having an electron-donating group bonded to a specific site of its ester-forming residue (its alcohol moiety) and optionally a lactone or lactide, while using an alkali metal alcoholate as a polymerization initiator. Moreover, it also provides a process for preparing the polymer and polymer micelles formed from the polymer. Since the polymer has a functional group corresponding to the polymerization initiator and the aforesaid electron-donating groups (functional groups), it can perform a great variety of functions by taking advantage of these functional groups.

Abstract: Metal salts of cyclic alcohols can be used as modifiers in lithium initiated solution polymerizations of diene monomers into rubbery polymers having a low vinyl content. For instance, such initiator systems can be used in the copolymerization of styrene and isoprene to produce low vinyl styrene-isoprene rubber having a random distribution of repeat units that are derived from styrene. It is important for such polymerizations to be conducted in the absence of polar modifiers, such as Lewis bases. The subject invention more specifically discloses an initiator system which is comprised of (a) a lithium initiator and (b) a metal salt of a cyclic alcohol, wherein said initiator system is void of polar modifiers. The present invention also discloses a process for preparing a rubbery polymer having a low vinyl content which comprises: polymerizing at least one diene monomer with a lithium initiator at a temperature which is within the range of about 5° C. to about 100° C.

Abstract: An acrylic resin composition comprises an organic silicon based compound that can be copolymerised with or mixed with acryl monomer or methacryl monomer in the acrylic resin. The acrylic resin composition may contain inorganic fine grains of which the hydroxyl group or the methyl group is bonded to their surface. A painted-film molded resin plate and a coating member for a solar cell panel use the above acrylic resin composition.

Abstract: The present invention provides a method for the preparation of hydrophilic water insoluble, gel-free copolymers of 2-hydroxyethyl methacrylate and at least one of acrylic acid or methacrylic acid, and 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate and acrylic or methacrylic acid, where the copolymers are prepared in a solution of water and alcohol using monomeric 2-hydroxyethyl methacrylate containing ethylene glycol dimethacrylate impurities up to about 0.15% by weight and substantially in the absence of a chain transfer agent. The copolymers are convertible to water soluble copolymers by pH adjustment. The invention also provides a method for the preparation of a copolymer of 2-hydroxyethyl methacrylate and 4-hydroxybutyl acrylate, and a homopolymer of 2-hydroxyethyl methacrylate in a solution of water and either a monoalcohol or a polyhydric alcohol.

Abstract: A continuous process for oligomers which do not contain, as polymerized units, carboxylic acid-containing monomers and their salts, including the steps of: (1) forming a reaction mixture, substantially free of carboxylic acid-containing monomers and their salts, containing: (i) 0.5 to 99.95% by weight of the reaction mixture of at least one ethylenically unsaturated monomer; and (ii) 0.05 to 25% by weight, based on the weight of the ethylenically unsaturated monomer, of at least one free-radical initiator; and (2) continuously passing the reaction mixture through a heated zone wherein the reaction mixture is maintained at a temperature of at least 150° C. and a pressure of at least 30 bars for from 0.1 seconds to 4 minutes to form terminally-unsaturated oligomers. In addition, processes for forming oligomers of vinyl acetate and oligomers of vinyl alcohol are disclosed. Mixtures of fully saturated and terminally unsaturated oligomers are also disclosed.

Abstract: Emulsifiable ethylene polymers comprising copolymers of from 90 to 95% by weight of ethylene, from 4 to 10% by weight of one or more C3-C12 alkenecarboxylic acids, and from 0 to 1.2% by weight of one or more tertiary esters of the corresponding C3-C12 alkenecarboxylic acids, where the wax has a cinematic melt viscosity of from 800 to 3000 mm2/s, measured at 120° C.; and a process for preparing the novel emulsifiable ethylene polymers, emulsions comprising the novel ethylene polymers, a process for preparing the emulsions from the novel ethylene polymers, and also floor cleaners, car cleaners, leather cleaners and stone cleaners, and coatings for surfaces made from wood, metal, paper, glass or from plastics, comprising aqueous emulsions of the novel emulsifable waxes.

Abstract: The invention provides a process for producing a saponified vinyl acetate polymer (a saponified ethylene-vinyl acetate copolymer in particular) which features a minimum of coloration of molding pellets, a well-inhibited emanation of an odor in melt-molding, a high transparency of the product film and a low incidence of fish-eyes in the film, and a process for producing a vinyl acetate polymer (particularly an ethylene-vinyl acetate copolymer) for use as the starting material for said saponified vinyl acetate polymer having said favorable properties. In accordance with the invention, either vinyl acetate alone or vinyl acetate and one or more other monomers are polymerized in the presence of a hydroxylactone compound and a polymerization catalyst. The resulting vinyl acetate polymer (particularly the ethylene-vinyl acetate copolymer) is then saponified.

Abstract: A potentially hydrophilic resin comprises at least monomer units readily saponifiable under alkaline conditions to form carboxyl groups, carboxyl-containing monomer units, and hydroxyl-containing monomer units. A potentially hydrophilic resin composition comprises, in a liquid medium, the potentially hydrophilic and an adhesive component or film-forming component. A recycling method is provided for an article with a coating applied on a surface thereof. According to the recycling method, the coating on the surface of the article is formed with the potentially hydrophilic resin composition, and subsequent to use of the article, the article is treated with alkaline water to saponify methyl acrylate in the coating such that the coating is caused to swell, and the coating so swollen is removed from the article.

Abstract: An inorganic dispersion stabilizer having a hydrophobic inorganic oxide such as hydrophobic silica dispersed in an aqueous medium in the presence of an hydrophilic organic compound such as alcohol. An suspension polymerization process for producing resinous particles of a narrow particle diameter distribution by dispersing a monomer into an dispersion medium in the presence of the inorganic dispersion stabilizer, and polymerizing the monomer.

Abstract: The invention relates to a new improved catalyst to produce random copolymers of one or more iso-olefin monomers and one or more para-alkylstyrene monomers. The invention also relates to an improved continuous slurry polymerization process to produce random copolymers using the improved catalyst system. The process is carried out in an anhydrous polymerization system containing a mixture of the monomers in a polar solvent along with a Lewis acid and a stabilizing initiator.

Abstract: Use of surfactants in the suspension polymerization of fluorinated monomers for preparing fluoropolymers containing hydrogen, said surfacants having the general formula:

Abstract: A process for preparing low molecular weight, highly reactive polyisobutylene having an average molecular weight Mn of from 500 to 5000 Dalton and a terminal double bond content of more than 80 mol % by polymerization in the liquid phase of isobutene or hydrocarbon streams comprising isobutane [sic] with the aid of a boron trifluoride complex catalyst at from −40 to 20° C. and at from 1 to 20 bar comprises a) polymerizing until the residual isobutene content of the reaction mixture is less than 2% by weight, based on isobutene introduced, or removing residual isobutene towards the end of the polymerization until the residual isobutene content is less than 2% by weight, b) enriching the boron trifluoride complex catalyst which is obtained in the form of droplets in the disperse and/or coherent phase, c) recycling the complex-enriched phases to the polymerization and d) compensating for catalyst losses by adding boron trifluoride and, if necessary, complexing agents.

Abstract: The invention relates to a process for transitioning from polymerizing sticky polymer to polymerize another sticky polymer in gas phase fluidization bed production to decrease transition time, reduce off-grade material, and/or prevent operational difficulty.

Abstract: A free-radical polymerization process for making macromonomers having the structure: comprising contacting: (a) CH2═CHY; (b) optionally, CH2═CXB; and (c) free-radicals, produced from a free-radical source; in which B, U, X, Y, Z, m, n and p are defined in the text; macromonomer quality being controlled by adjusting one or more of the following variables: molar ratios of a, b and c; temperature; monomer concentration; and conversion.

Abstract: The present invention provides a high temperature continuous polymerization and condensation process for preparing a polymeric product. The process includes continuously charging into a reaction zone: at least one radically-polymerizable monomer having a radically polymerizable group and at least one condensation reactive functionality; and at least one modifying agent having a functional group capable of reacting with the condensation reactive functionality. The reaction zone includes at least one primary reactor, but may, and preferably does, contain a secondary reactor. The process further includes maintaining an effective temperature in the primary reactor to cause polymerization of the monomer and to allow at least a portion of the condensation reactive functionality to react with the functional group of the modifying agent.

Abstract: The present invention provides a high temperature continuous polymerization and condensation process for preparing a polymeric product. The process includes continuously charging into a reaction zone: at least one radically-polymerizable monomer having a radically polymerizable group and at least one condensation reactive functionality; and at least one modifying agent having a functional group capable of reacting with the condensation reactive functionality. The reaction zone includes at least one primary reactor, but may, and preferably does, contain a secondary reactor. The process further includes maintaining an effective temperature in the primary reactor to cause polymerization of the monomer and to allow at least a portion of the condensation reactive functionality to react with the functional group of the modifying agent.

Abstract: The process for producing bead polymers having a mean particle size of 0.5 to 50 &mgr;m and a narrow particle size distribution by polymerisation of monomers dissolved in a solvent that constitutes a precipitation agent for the polymers obtained from these monomers is characterized in that the solvent contains 5 to 3000 ppm of sulfur-free radical interceptors.

Abstract: A copolymer comprising units derived from (a) methaciylic acid esters containing from about 9 to about 25 carbon atoms in the ester group and (b) methacrylic acid esters containing from 7 to about 12 carbon atoms in the ester group, said ester groups having 2-(C1-4 alkyl)-substituents, and optionally (c) at least one monomer selected from the group consisting of methacrylic acid esters containing from 2 to about 8 carbon atoms in the ester group atoms and which are different from methacrylic acid esters (a) and (b), vinyl aromatic compounds, and nitrogen-containing vinyl monomers with the proviso that no more than 60% by weight of the esters contain not more than 11 carbon atoms in the ester group. Also described are additive concentrates and lubricating oil compositions containing the copolymers and processes for preparing copolymers.

Abstract: Disclosed is a process for preparing temperature-responsive polymers that may be formed into a thermally-processable form which exhibits flushability properties when immersed in water such that the temperature-responsive polymer may be used in a disposable absorbent product to impart flushability properties to the product. The process prepares the temperature-responsive polymer in an aqueous solution using a chain transfer agent such as isopropanol.

Abstract: The present invention provides a high temperature continuous polymerization and condensation process for preparing a polymeric product. The process includes continuously charging into a reaction zone: at least one radically-polymerizable monomer having a radically polymerizable group and at least one condensation reactive functionality; and at least one modifying agent having a functional group capable of reacting with the condensation reactive functionality. The reaction zone includes at least one primary reactor, but may, and preferably does, contain a secondary reactor. The process further includes maintaining an effective temperature in the primary reactor to cause polymerization of the monomer and to allow at least a portion of the condensation reactive functionality to react with the functional group of the modifying agent.

Abstract: The present invention relates to a process for the preparation of microencapsulated polymers having a high surface smoothness, a soluble fraction of less than 6%, and a swelling index of between 1.3 and 9 by polymerizing a microencapsulated monomer mixture suspended in an aqueous phase containing at least one hydroxyaromatic compound as polymerization inhibitor, wherein the microencapsulated monomer mixture contains (a) 34 to 99.7% by weight of a monomer having one polymerizable C═C double bond, (b) 0.1 to 15% by weight of a crosslinking agent having at least 2 polymerizable C═C double bonds, (c) 0.2 to 1.0% by weight of at least one aliphatic peroxyester as polymerization initiator, and (d) 0 to 50% by weight of additives, the percentages being based on the sum of the components (a) to (c).

Abstract: Unsheared, water-soluble, branched, high molecular weight, anionic, polymeric flocculants are produced by polymerizing ethylenically unsaturated anionic, and optionally non-ionic, monomers and a branching agent in the presence of a chain-transfer agent. They are useful as flocculating agents for releasing water from dispersions of suspended solids.

Abstract: A process for preparing highly concentrated aqueous solutions of low molecular mass homopolymers of N-vinylpyrrolidone by free-radical solution polymerization in an aqueous medium with H2O2 as initiator comprises carrying out the polymerization in the presence of from 0.1 to 30% by weight, based on N-vinylpyrrolidone, of a polymerization regulator which is selected from the group consisting of C1-C6-alkanols, hydroxylamine salts and water-soluble compounds containing sulfur in bonded form.

Abstract: A process for preparing an aqueous emulsion with a narrow droplet size distribution of an oily material comprising one or more highly water insoluble substances, wherein the oily material is homogenized in a hydrophilic phase in which the oily material is more soluble than in water, but still so insoluble that an emulsion is formed by the homogenization, and the emulsion is subsequently diluted with a high proportion of water to form a stable emulsion of the oily material having the desired narrow size distribution. The stable emulsion may be mixed with an excess of a partly water soluble material which becomes absorbed by the droplets of the oily material. Said partly water soluble material may comprise a polymerizable monomer, and polymerization is subsequently effected to prepare a dispersion of polymer particles, and if desired, the polymer particles are recovered from said dispersion.

Abstract: A controlled free-radical polymerization process for forming end-functionalized polymers is disclosed, particularly by degenerative iodine transfer. The end-functionalized polymers are characterized by a polydispersity less than 2.5 and a predetermined molecular weight. The end-functionalized polymers are useful as reactive intermediates in condensation polymerization, chain polymerization and heterogeneous polymerization reactions.

Abstract: Living random (meth)acrylic copolymers, facilely converted into random co(meth)acrylates and block copolymers thereof, comprise the anionic copolymerizates of at least one comonomer A with at least one comonomer B selected from among the (meth)acrylates and maleimides, at least one of the comonomers A and B comprising a (meth)acrylate, in the presence of (i) at least one alkali or alkaline earth metal, mono- or difunctional initiator and (ii) at least one ligand, for example a nonnitrogenous macrocyclic complexant, e.g., a crown ether, or an alkali metal alcoholate.

Abstract: A method for producing a catalyst for the polymerization or copolymerization of olefins is described. The method includes producing a magnesium compound solution by reacting a magnesium halide compound in the mixture of a cyclic ether and two alcohols with an organosilane compound. The magnesium compound solution may be reacted with a titanium halide compound such that precipitated solid components are formed. These precipitated solid components may be reacted with a titanium compound and an electron donor to produce the polymerization catalyst.

Abstract: The present invention provides substituted phenols which are effective to inhibit polymer formation during the manufacture of acrylonitrile. Preferred substituted phenols are (a) hindered phenols, nonhindered phenols, and partially hindered phenols, or (b) combinations of hindered phenols with nonhindered or partially hindered phenols. A most preferred substituted phenol is p-nitrosophenol. In a preferred embodiment, the substituted phenols (with the exception of p-nitrosophenol) are combined with hydrogen transfer agents.

Abstract: This invention relates to polymers that are formed by polymerizing a reaction mixture that comprises at least one silicone-containing monomer and at least one hydrophilic monomer. More particularly, this invention relates to polymers formed by polymerizing a reaction mixture that comprises at least one silicone-containing monomer and at least one hydrophilic monomer in the presence of a diluent.

Abstract: Use of surfactants in the suspension polymerization of fluorinated monomers for preparing fluoropolymers containing hydrogen, said surfacants having the general formula:R.sub.f --[L--(OCHR.sub.1 --CHR.sub.2).sub.m --OZ)].sub.iwherein:i is equal to 1 or 2;m is an integer comprised between 4 and 60;L can be chosen between: --(CFY--CO--O).sub.p R'-- and --(CFY--CO--NH).sub.p R'--wherein p is an integer equal to 0 or to 1;Y=F, CF.sub.3 ; R'=alkylic radical C.sub.1 -C.sub.5, linear or branched when possible;R.sub.1, R.sub.2 can be both H or the former H and the latter CH.sub.3 ;Z can be H, alkyl radical C.sub.1 -C.sub.3, linear or branched when possible; or (CH.sub.2).sub.n OH with n an integer from 1 to 6;R.sub.f is a perfluoroalkylic radical or a perfluoropolyether radical, having a number average molecular weight comprised between 250 and 1500.

Abstract: The present invention is directed to precipitation polymerization processes for the manufacture of polymers prepared from N-vinyl formamide monomer, the processes including the steps of contacting the N-vinyl formamide monomer with a polymerization medium containing t-butanol as diluent and a free-radical initiator, under conditions effective to polymerize the N-vinyl formamide monomer, thereby forming a precipitate of the polymer in the polymerization medium, substantially isolating the precipitated polymer from the polymerization medium, contacting the substantially isolated polymer with a wash containing a different diluent than the t-butanol used in the polymerization and isolating the washed polymer from the wash.

Abstract: Living random (meth)acrylic copolymers, facilely converted into random co(meth)acrylates and block copolymers thereof, comprise the anionic copolymerizates of at least one comonomer A with at least one comonomer B selected from among the (meth)acrylates and maleimides, at least one of the comonomers A and B comprising a (meth)acrylate, in the presence of (i) at least one alkali or alkaline earth metal, mono- or difunctional initiator and (ii) at least one ligand, for example a nonnitrogenous macrocyclic complexant, e.g., a crown ether, or an alkali metal alcoholate.

Abstract: Vinylphenol polymers are useful materials having many applications, vinylphenol polymers possessing an appropriate molecular weight corresponding to each of the applications are desired. However, it is very difficult to control the molecular weight of vinylphenol polymers, because vinylphenol monomer exhibits a very high reaction rate in the presence of a radical initiator, and it is very difficult to obtain vinylphenol polymers having molecular weight of from eight thousand to one hundred thousand. Further, vinylphenol monomer is very difficult to store, because it is rapidly polymerized even at room temperature. A simple process for preparing vinylphenol polymers having the molecular weight range mentioned above by simply adding methanol to the polymerization system is disclosed. A stabilized composition of vinylphenol suitable for use to prepare vinylphenol polymers, comprising vinylphenol-containing polymerization raw material and methanol as the indispensable constituents is also disclosed.

Abstract: Improved monodisperse spheroidal particle latices of vinyl chloride polymers, e.g., having particle sizes ranging from 0.17 to 0.8 .mu.m or from 0.5 to 1.2 .mu.m, are produced by aqueous emulsion polymerization of vinyl chloride monomer, whether in a single stage or in two stages, in the absence of surface-active agent, in the presence of at least 0.2% by weight of at least one water-soluble alkali metal or ammonium persulfate initiator, and also in the presence of at least one water-soluble auxiliary compound that is a solvent for vinyl chloride, in such amount that the solubility of vinyl chloride in the aqueous phase at 25.degree. C. at atmospheric pressure is at least 1.5 g/l.

Abstract: The present invention provides adhesive compositions which include free radical polymerizable compounds and a redox catalyst system to accelerate polymerization thereof. The redox catalyst includes an aniline derivative substituted in the para position by halogen as an accelerator. The use of para-halogenated aniline derivatives as an accelerator in the cure of free radical polymerizable compounds results in good bond strength and greatly improved surface cure of the adhesive composition.

Abstract: Polyisobutene having an average molecular weight M.sub.n of from above 5000 to 80,000 dalton and containing more than 50 mol % of terminal double bonds is prepared by a novel process, by cationic polymerization of an isobutene-containing hydrocarbon mixture in. the liquid phase in the presence of a boron trifluoride complex catalyst, and has a dispersity of M.sub.w /M.sub.n of from 2 to 4 and is contained in lubricants.

Abstract: A process for the preparation of a resin comprising:heating a mixture of at least one free radical polymerizable monomer, a free radical initiator compound, a stable free radical compound, and a reducing agent.

Abstract: An alkyl-containing porous resin with a specific surface area of 50 to 600 m.sup.2 /g, the resin being prepared by polymerizing a monomer mixture of, based on the total weight of the monomers, 15 to 97% by weight of divinylbenzene, 0 to 82% by weight of at least one aromatic monovinyl monomer selected from the group consisting of styrene, methylstyrene and ethylvinylbenzene and 3 to 50% by weight of a vinylbenzyloxyalkane derivative represented by the formula ##STR1## wherein n is an integer of 1 to 18, a process for its preparation and its use.The porous resin of the invention is capable of fully exhibit its modified functions based on the variations of chemical and structural environments on the surface of resin, the functions being modified by introducing alkyl groups having varying chain lengths.

Abstract: Described are preferred processes for producing linear polyvinylpyridines. The processes involve the use of hydrogen peroxide to initiate polymerization of vinylpyridine monomers in an aqueous solvent. Processes of the invention provide good reaction rates and conversions, and are particularly advantageous in achieving control of the M.sub.w 's of the final product polymers.

Abstract: (i) A method for emulsion polymerization of tetrafluoroethylene, which comprises emulsion-polymerizing tetrafluoroethylene in the presence of a polymerization initiator, a paraffin wax containing not larger than 100 ppm of a reducing substance and an emulsifier, and (ii) a method for preventing irregular polymerization of tetrafluoroethylene, which comprises using the above method for emulsion polymerization give a constant polymerization time, and polytetrafluoroethylene having values of physical properties which meet the desired standard requirements.

Abstract: The present invention provides a novel halogen-free solvent system which can produce a good isobutylene polymer and can be easily reused. A novel process for the production of an isobutylene polymer is provided which comprises using a hydrocarbon solvent having a boiling point of not lower than 105.degree. C. and a melting point of not higher than -90.degree. C. Heretofore, a solvent system containing a halogenated hydrocarbon such as methylene chloride has been used for the production of an isobutylene polymer. However, such a solvent system has a great adverse effect on the environment. Therefore, a non-halogenated solvent is desirable. The present invention is characterized by the use of a hydrocarbon solvent as a reaction solvent. The resulting polymer has good properties. Further, compounds which are produced as by-products during the reaction can be easily removed, enabling the recycling of the solvent used. Thus, the production cost can be reduced.