Patent Description:
Isobutylene copolymers are known in the art. The materials are generally reported useful in preparing fuel and lubricating oil additives when derivatized with maleic anhydride and optionally amines.

There is disclosed in <CIT>) isobutylene/diene copolymers with at least <NUM>% vinylidene groups. This reference relates to isobutylene/butadiene copolymers for the most part. Example <NUM>, Col. <NUM>, includes a reactant mixture of C5s including isoprene, pentadienes and cyclopentadienes. Conversions of the various diene monomers in Example <NUM> are not reported. Reaction is carried out in a loop reactor with the reactants in hexane solvent (<NUM>:<NUM>) at -<NUM>.

<CIT>) discloses a process for making isobutylene/isoprene copolymers with an Mn of <NUM>,<NUM> or so in an autoclave. Conversions are quite low, particularly where isoprene concentrations exceed about <NUM>%.

<CIT>) discloses isobutylene/diene copolymers made with chloride catalysts which are derivatized with anhydrides/amines for fuel additives. Examples specify isoprene/isobutylene made in a <NUM> continuous reactor at -<NUM>. See also, <CIT>) which discloses carboxylated isobutylene/polyene polymers for lubricating oil additives wherein carboxylation is carried out with maleic anhydride. The copolymers of the '<NUM> patent are made with aluminum trichloride catalyst.

It is apparent from the foregoing references that improved methodologies for manufacture of isobutylene copolymers are needed in order to provide for more efficient manufacture and more reactive isobutylene copolymers.

The copolymers made by the method of the present invention are useful in a variety of applications including fuel and lubricating oil additives, rubber compositions and products as well as applications not typically employing polyisobutylenes such as in unsaturated polyester resins, polyurethanes, adhesives, sizings, oxirane derivatives and so forth as is described hereinafter.

The copolymers made by the method of the present invention, which are typically chloride-free, can be tailored to the particular end use in terms of molecular weight and functionality to provide superior novel products which are more easily formulated and prepared than traditional products.

It has been found in accordance with the present invention that isobutylene copolymers with an increased double bond content or selective incorporation of comonomers can be prepared in high yield at low reactor residence times. Suitable reactor temperatures are above -<NUM>. Comonomers used with isobutylene include: isoprene,
<CHM>
cyclopentadiene,
<CHM>
dicyclopentadiene,
<CHM>
butadiene,
<CHM>
limonene,
<CHM>
alpha methyl styrene,
<CHM>
para methyl styrene,
<CHM>
other substituted styrenes; piperylene,
<CHM>
and C4 to C10 dienes other than isoprene, cyclopentadiene, dicyclopentadiene, butadiene and piperylene, as well as like comonomers, such as α-terpenes and β-terpenes. The comonomers may be used in combination if so desired.

There is thus provided in accordance with the present invention a method of making an isobutylene copolymer comprising: (a) providing a reaction mixture to a reactor comprising isobutylene monomer, and one or more comonomers selected from isoprene, butadiene, cyclopentadiene, limonene, substituted styrenes, and C4 to C10 dienes other than isoprene, butadiene, limonene or cyclopentadiene as well as a Lewis acid polymerization catalyst, wherein the mole ratio of isobutylene to the comonomer is from <NUM>:<NUM> to <NUM>:<NUM>; (b) polymerizing the reaction mixture while maintaining the reactor at a temperature of from <NUM> to <NUM> and utilizing a reactor residence time of less than <NUM> minutes to produce a crude isobutylene copolymer in a polymerization mixture; and (c) recovering a purified isobutylene copolymer from the polymerization mixture having a molecular weight, Mn of from <NUM> to <NUM>,<NUM> Daltons; with the provisos that (i) when the comonomer is isoprene, butadiene or mixtures thereof, the purified isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM>
Daltons and (ii) when the comonomer comprises a substituted styrene the purified copolymer has a molecular weight, Mn, of from <NUM> to <NUM> Daltons.

In another aspect of the invention there is provided an isobutylene copolymer of claim <NUM> comprising repeat units derived from isobutylene and repeat units derived from isoprene as a comonomer, wherein the molar ratio of isobutylene derived repeat units to the comonomer derived repeat units is from <NUM>:<NUM> to <NUM>:<NUM> and the isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM> Daltons, at least <NUM> double bonds per molecule and greater than <NUM> vinylidene double bonds per molecule.

The copolymers made by the method of the present invention are useful in products such as fuel and lubricating oil additives as well as rubber compositions, adhesives, sizings, functionalized copolymers, unsaturated polyesters, polyurethanes, oxirane derivatives and so forth as described hereinafter. The copolymers described herein provide enhanced properties in such products, for example, better sizing properties based on multiple succinic anhydride groups per molecule allowing better integration into the paper product and superior sizing properties. Note <FIG>, wherein it is seen that paper sizings made with the copolymers made by the method of the present invention exhibit relative water repellency more than <NUM>% higher than conventional products.

Still further features and advantages of the invention will become apparent from the discussion which follows.

The invention is described in detail below with reference to the various Figures, wherein:.

The invention is described in detail below with reference to several embodiments and numerous examples. Such discussion is for purposes of illustration only. Modifications to examples within the spirit and scope of the present invention, set forth in the appended claims, will be readily apparent to one of skill in the art. Terminology used throughout the specification and claims herein is given its ordinary meaning, for example, psi refers to pressure in lbs/inch<NUM> (psia indicates absolute pressure and psig indicates gauge pressure) and so forth. Terminology is further defined below and test methods are specified.

Absorptiveness of sized paper is measured using a modified Cobb test (TAPPI Test Method T-<NUM> or equivalent) as described herein.

"Blending" and like terminology refers to intimate mixing of two or more feedstocks and includes simultaneously feeding two feedstocks to a reactor (in situ combination).

"Chloride free" and like terminology refers to compositions with less than <NUM> ppm chlorine content.

"Consisting essentially of" and like terminology refers to the recited components and excludes other ingredients which would substantially change the basic and novel characteristics of the mixture or composition. Unless otherwise indicated or readily apparent, a composition or mixture consists essentially of the recited components when the composition or mixture includes <NUM>% or more by weight of the recited components. That is, the terminology excludes more than <NUM>% unrecited components.

Conversion of the reaction mixture to polymer is expressed in percent and calculated as the weight (or moles) of monomer incorporated into the copolymer produced less the weight (or moles) of monomer fed to the reaction system divided by the weight (or moles) of monomer fed to the reaction system times <NUM>. Conversion, selectivity and yield are related by the mathematical definition X(conversion) * S(selectivity) = Y(yield), all calculated on either a weight or molar basis; e.g. in a certain reaction, <NUM>% of substance A is converted (consumed), but only <NUM>% of it is converted to the desired substance B and <NUM>% to undesired by-products, so conversion of A is <NUM>%, selectivity for B <NUM>% and yield of substance B is <NUM>% (= <NUM>% * <NUM>%). For copolymers conversion, selectivity and yield is calculated for each comonomer based on feed and incorporation into the product.

Hydrophobicity index is a measure of relative water repellency as described herein.

Kinematic viscosity of the copolymer products of the invention may be expressed in Cst @<NUM> and is preferably measured in accordance with Test Method ASTM D <NUM>.

Molecular weight herein is typically reported as number average molecular weight, Mn, in Daltons, and is measured by Gel Permeation Chromatography (GPC). GPC measurements reported herein were carried out using a Viscotek GPCmax® instrument (Malvern instruments, Worcestershire, UK) employing a <NUM>-column set-up (<NUM> (particle size) <NUM> Angstrom (pore size), <NUM> 500Angstrom, <NUM> <NUM><NUM>Angstrom) and a Refractive Index (RI) detector. Polyisobutylene standards were used to construct the calibration curve.

Polydispersity or PDI is defined as the ratio of the weight average molecular weight divided by the number average molecular weight of the polymer.

"Glass transition temperature" or Tg, of a composition refers to the temperature at which a composition transitions from a glassy state to a viscous or rubbery state. Glass transition temperature may be measured in accordance with ASTM D7426, ASTM D3418 or equivalent procedure as described herein.

"Melting temperature" refers to the crystalline melting temperature of a semicrystalline composition. Melting temperatures may also be measured in accordance with ASTM D3418 or equivalent procedure.

Copolymers made by the method of the invention have significant amounts of alpha vinylidene terminated molecules due to the isobutylene content of the copolymers and their method of manufacture:
<CHM>
Reactive end groups present may also include beta olefin isomers (<NUM>,<NUM>,<NUM>-trisubstituted or <NUM>,<NUM>,<NUM>-trisubstituted cis or trans isomer):
<CHM>
<CHM>
Other end group structures which may be present include tetrasubstituted structures, other trisubstituted structures with a double bond in the internal gamma position, structures with other internal double bonds and aliphatic structures, for example:
<CHM>
<CHM>
<CHM>
<CHM>.

The materials prepared by the method of the present invention may be characterized by double bond content based on monomer conversion or direct measurement by <NUM>H NMR and <NUM>C NMR as is seen in <NPL>; <NPL>; <NPL>; and <NPL>.

One sees different structures in the copolymer product, depending upon the comonomer species and the mechanism of addition of comonomer. For example, isobutylene/isoprene copolymer may have one of the following structures depending upon whether the addition of isoprene is a <NUM>,<NUM> or <NUM>,<NUM> or <NUM>,<NUM> addition to the copolymer chain:
<CHM>
The molecules may have chain ends besides the alpha terminated chains seen above, including beta or tetra structures on the chain ends.

For present purposes, we refer to "vinylidine" double bonds as including alpha vinylidene double bonds and the internal vinylidine double bonds seen in the latter two structures, above, as well as the "internal alpha" structure referred to in <CIT>, entitled Polyisobutylene Composition Having Internal Vinylidene and Process for Preparing the Polyisobutylene Polymer Composition:
<CHM>
In general, "vinylidene" double bonds thus refer to reactive double bonds in the molecule that are CH<NUM> terminated.

In the examples which follow, the content of vinylidine double bonds was determined based on <NUM>-NMR spectroscopy in deuterated chloroform as the solvent. The olefinic methine hydrogens of the <NUM>,<NUM> isoprene give the triplet at <NUM> ppm. The olefinic methylene hydrogens from the isoprene show a doublet at <NUM> ppm. The peak at value <NUM> and <NUM> ppm is due to the formation of double bond at the endunit in the chain. Two major isobutyl signals at <NUM> ppm and <NUM> ppm are due to methyl and methylene protons of polyisobutylene units of the isobutylene-isoprene copolymer. Besides these signals there are other signals due to the presence of isoprenyl unit in the copolymer. These signals are reported in the literature noted above.

The improved process of the present invention features the use of Friedel-Crafts or Lewis acid catalysts which are typically complexed with a complexing agent. Many useful Lewis acid catalysts are known to those of ordinary skill in the related art field. In particular, many useful catalysts are described in the patents referenced above. Useful Lewis acid catalysts include, for example, BF<NUM>, AlCl<NUM>, TiCl<NUM>, BCl<NUM>, SnCl<NUM> and FeCl<NUM> and the like. The complexing agent for the catalyst, and in particular for the BF<NUM> catalyst, may be any compound containing a lone pair of electrons, such as, for example, an alcohol, an ester or an amine. The complexing agent may be an alcohol, desirably a primary alcohol, preferably a C1-C8 primary alcohol (such as, for example, methanol, ethanol, propanol, isopropanol, hexyl alcohol and the like) and ideally methanol. For purposes of convenience, "catalyst" refers to a Lewis acid catalyst of the class described above, while "catalyst complex" refers to the Lewis acid catalyst and complexing agent up to a <NUM>:<NUM> molar ratio. When complexing agent is used in a molar excess with respect to the Lewis acid catalyst it is referred to herein as modifier. Preferred Lewis acids which can be used are complexes of Aluminum Trichloride and/or Ethyl Aluminum Dichloride with C1-C5 alcohol and/or ether as modifier.

The catalyst employed is most preferably a BF<NUM> catalyst together with a modifier, sometimes referred to as a cocatalyst or complexing agent. The modifier for the BF<NUM> catalyst may be any compound containing a lone pair of electrons, such as, for example, an alcohol, ether, an ester or an amine or mixtures thereof. The alcohol compound used as the cocatalyst may be a primary, secondary or tertiary alcohol having <NUM> to <NUM> carbon atoms, such as, for example, methanol, ethanol, isopropanol, n-propanol, isobutanol, t-butanol, hexyl alcohol and the like. The ether compound used as the cocatalyst may be a primary, secondary or tertiary ether having <NUM> to <NUM> carbon atoms, such as, for example, dimethyl ether, diethyl ether, diisopropyl ether, methylpropyl ether, methylisopropyl ether, methylethyl ether, methylbutyl ether, methyl-t-butyl ether, ethylpropyl ether, ethylisopropyl ether, ethylbutyl ether, ethylisobutyl ether, ethyl-t-butyl ether and the like. The complexing agent may be added to the reactor, in whole or in part, separately from the BF<NUM> catalyst, or pre-mixed therewith and added to the reactor together with the BF<NUM> catalyst. Likewise, modifier may be added to the reactor separately from the catalyst and complexing agent or pre-mixed therewith and added to the reactor together with the BF<NUM> catalyst and complexing agent.

In one embodiment, the polymerization reaction is carried out in the presence of a catalyst system comprising secondary alkylether, tertiary alcohol, and boron trifluoride, the amount of boron trifluoride is <NUM>-<NUM> weight part per <NUM> weight part of monomer, the mole ratio of a co-catalyst including secondary alkylether and tertiary alcohol:boron trifluoride is <NUM>-<NUM>:<NUM>, and the mole ratio of secondary alkylether:tertiary alcohol is <NUM>-<NUM>:<NUM>.

In many embodiments, the estimated molar ratio of modifier to BF<NUM> in the catalyst composition is generally in the range of from approximately <NUM>-<NUM> to <NUM>, desirably within the range of from approximately <NUM>:<NUM> to approximately <NUM>:<NUM>, and in some cases within the range of from approximately <NUM>:<NUM> to approximately <NUM>:<NUM>. In some cases, the catalyst estimated composition may simply be a <NUM>:<NUM> molar complex of BF<NUM> and alcohol and ether mixtures In other preferred embodiments of the invention, the estimated molar ratio of complexing agent:BF<NUM> in said complex may be approximately <NUM>:<NUM>.

The temperature in the reaction zone may be maintained at a constant level at a temperature of suitably <NUM> or above or wherein the reactor is maintained at a temperature of <NUM> or <NUM> or above. Temperatures in the range of above <NUM> to <NUM> are typical. The residence time is <NUM> minutes or less, <NUM> minutes or less or <NUM> minutes or less. Suitable pressures may be anywhere from <NUM>-<NUM> bar to maintain a liquid phase.

In some embodiments, it is desirable to use one or more inert diluents such as an alkane (e.g., isobutane, n-butane, hexane and the like).

The products of the invention may be made in a continuous stirred tank reactor (CSTR), a plug flow reactor (PFR) or a loop reactor in a liquid phase process.

The flow characteristics of the reaction mixture are also influenced by temperature in the reactor, molecular weight, monomer and diluent content and so forth as is readily appreciated by one of skill in the art. The flow characteristics of the reaction mixture are thus controlled by feed and catalyst rates, conversion of monomer, mixture composition and the temperatures in the reactor as is seen in the examples which follow.

Typically, the inventive process is operated in a loop reactor wherein the recirculation rate is much higher than the feed rate; ratios of recirculation to feed ratios may be anywhere from <NUM>:<NUM> to <NUM>:<NUM>.

Referring to <FIG>, there is shown schematically a reactor system <NUM> which includes a two-pass loop reactor <NUM>, a recirculation pump <NUM>, a feed and recirculation loop indicated at <NUM>, a product outlet indicated at <NUM> and a feed inlet indicated at <NUM>. Reactor <NUM> includes a plurality of reaction tubes indicated at <NUM>, <NUM> in a two-pass configuration within a heat exchanger shell indicated at <NUM>.

In operation, isobutylene and comonomer feedstock, catalyst and modifier is continuously fed at <NUM> to the system, while pump <NUM> operates at a pressure differential to recirculate the reaction mixture in reactor <NUM> via loop <NUM>, while product is continuously withdrawn at <NUM>. Details of operating reactor <NUM> are provided in <CIT>.

Instead of a homogeneous catalyst feed, a fixed bed loop reactor having generally the construction of <FIG> is provided with heterogeneous catalyst packed in the tubes of described heat exchanger. In such cases, a supported BF<NUM>:alcohol catalyst is charged to the system as is seen in <CIT>, entitled Activated Inorganic Metal Oxide and <CIT>, entitled Polyisobutylene Composition Having Internal Vinylidene and Process for Preparing the Polyisobutylene Polymer Composition. Optionally, additional liquid catalyst complex is injected into the system to replenish the catalyst charge.

In still another embodiment, the present invention is practiced in a CSTR, as shown schematically in <FIG>. CSTR apparatus <NUM> includes a pressurized reaction vessel <NUM> provided with a cooling jacket <NUM>, a feed port <NUM>, one or more baffles <NUM>, <NUM>, an outlet port <NUM>, as well as an agitator <NUM>, driven by a motor <NUM> via shaft <NUM>.

In operation, the isobutylene and comonomer feedstock, together with catalyst and modifier, is fed continuously to vessel <NUM> in the liquid phase through feed port <NUM>, while motor <NUM> drives agitator <NUM> via shaft <NUM> to keep the reaction mixture thoroughly mixed. The feed rate, cooling jacket temperature and catalyst concentration are manipulated to keep the reactor at the desired temperature and to achieve target conversion as product is continuously withdrawn from outlet port <NUM> after a characteristic steady state residence time in the reactor.

The residence time, feed composition and temperature in all cases are important features towards achieving the desired properties in the copolymer product. Preferably, at least a relatively high temperature and/or a short residence time is employed.

Following withdrawal from the reactor, the reaction mixture is quenched to deactivate the catalyst, preferably with an inorganic base such as sodium hydroxide or ammonium containing catalyst deactivator such as ammonium hydroxide. The effluent is then washed with water to remove salts as described in <CIT>. Following washing, the processed effluent is flashed or distilled to remove oligomers in order to provide a purified product as is discussed herein.

Suitably, after washing the product is heated to a temperature of <NUM> or above as part of the purification processes to further remove fluorides. Suitable treating temperatures may be from <NUM> to <NUM> or so, optionally at lower than atmospheric pressure (taking care not to overheat the polymer), to further remove quench salts while removing oligomers. A particularly preferred range is from <NUM> to <NUM>. A suitable post-reactor purification methodology is illustrated in connection with <FIG>.

In <FIG> there is illustrated schematically a process and apparatus <NUM> for purifying isobutylene copolymer produced in reactors such as reactors <NUM>, <NUM> described above. The reactor outlet (for example, outlet <NUM> or outlet <NUM>) feeds line <NUM> which is connected to a washing and decanting system <NUM>. Line <NUM> provides a quenching agent such as aqueous ammonium hydroxide in excess of the amount needed to quench the catalyst. At <NUM>, the quenched mixture is washed with water provided by way of line <NUM> and separated into two phases, an aqueous phase containing catalyst reside and ammonium hydroxide and a hydrocarbon phase containing polymer, un-reacted monomer and solvents. The aqueous phase exits <NUM> via line <NUM> for further processing and recycle, while the organic phase exits <NUM> via line <NUM> and is heated and flashed at <NUM> under positive pressure at temperatures of <NUM>-<NUM> to remove monomer and light oligomers, usually up to C12 oligomers which exit via line <NUM> for further processing.

The partially purified isobutylene copolymer is forwarded via line <NUM> to a vacuum flash or distillation unit <NUM>, where the product is further purified by distillation to remove oligomers, especially C8 to C24 oligomers at temperatures of from <NUM> - <NUM> and pressures of from <NUM> psia to <NUM> psia or so. Alternatively, a wipe film evaporator or like apparatus can be employed to eliminate oligomers from the composition. The purified isobutylene copolymer product is removed at <NUM>.

Using a loop reactor as in <FIG>, polymerization was carried out by providing isobutylene, isoprene, along with BF<NUM> catalyst and a methanol co-catalyst to the circulation loop. Isobutylene and isoprene are dried on molecular sieves before use. The blended feedstock was fed to the reactor and polymerized in the liquid phase at the temperatures indicated in Table <NUM> below and an average residence time of less than <NUM> minutes; typically <NUM> minutes. Methanol/BF<NUM> molar ratio was provided in the range of <NUM>-<NUM>. After the completion of reaction, polymer was quenched with NH<NUM>OH and washed with water. Wash water was separated off and product was further purified by vacuum distillation. The purified product (IP-PIB) had isobutylene conversions by weight %, isoprene conversion by weight %, average number of double bond per polymer molecule between <NUM>-<NUM>, molecular weight, Mn, in Daltons and a vinylidine double bond content per molecule as indicated in Table <NUM> below.

The number of double bonds per molecule in the foregoing Table is calculated from the conversion and molecular weight data as the average number of diene-derived units per molecule plus one. The average number of diene units is calculated by dividing the number average molecular weight, Mn, of the polymers by the molar average molecular weight of the repeat units incorporated into the copolymer and multiplying by the mole fraction isoprene units in the copolymer. Molar contents are calculated from the conversion data. Thus, for Product <NUM>, the average number of double bonds per molecule is calculated as <NUM> + <NUM> or <NUM> using the foregoing data and densities of <NUM> and <NUM> for isoprene and isobutylene, respectively. For purposes of the calculation, molecular weights of <NUM> and <NUM> are used for isoprene and isobutylene. The average number of double bonds for Product <NUM> is thus calculated: <MAT>.

Some preferred products of isobutylene/isoprene copolymers are enumerated in Table 1A below.

The general, typical and preferred ranges for each feature in Table 1A can be interchanged for a specific embodiment made by the method of the present invention, for Example a polymer of <NUM> Daltons molecular weight may have the molar ratios and double bond features of the preferred ranges and so forth. Table 1A thus represents <NUM> specific combinations of ranges for molecular weight, molar ratios of isobutylene:isoprene derived repeat units, double bonds/molecule and vinylidene bonds/molecule for isobutylene-isoprene copolymers, which can be prepared according to the invention.

Utilizing a <NUM> reaction vial, <NUM>% of isoprene was mixed with isobutylene and equilibrated a reaction mixture to -<NUM>° C. Subsequently, methanol/BF<NUM> catalyst in a <NUM>:<NUM> molar ratio was added and the mixture reacted for <NUM> minutes, and then the polymer was quenched with NH4OH and washed with water. The product was further purified by vacuum distillation to remove unreacted product volatiles. Purified product had isobutylene conversion of less than <NUM>% with a number average molecular weight of Mn <NUM>. Despite a residence time of <NUM> minutes (more than twice the residence time of the loop reactor examples noted above) isobutylene conversions were less than about <NUM>%.

Using a loop reactor of the class described in connection with <FIG>, polymerization was carried out by providing isobutylene, para- methyl styrene (pmStyrene), along with BF<NUM> catalyst and a methanol co-catalyst to the circulation loop. Isobutylene and isobutane are dried on molecular sieves before use. The blended feedstock was fed to the reactor and polymerized in the liquid phase at the temperatures indicated in the table below and an average residence time of less than <NUM> minutes; typically <NUM> minutes. Methanol/BF<NUM> molar ratio was provided in the range of <NUM>-<NUM>. After the completion of reaction, polymer was quenched with NH<NUM>OH and washed with water. Wash water was separated off and product was further purified by a <NUM> stage flash separation. The purified product had isobutylene conversions by weight % and percentage incorporation of para methyl styrene in the polymer chain as indicated in Table <NUM> below.

In Examples <NUM>-<NUM> the percentage of para-methyl styrene incorporation in the polymeric chain was calculated based on proton NMR spectroscopy. For products <NUM>-<NUM>, aromatic region peaks between <NUM>-<NUM> ppm are due to aromatic protons, whereas peaks between <NUM>- <NUM> are due to aliphatic protons. Based on the peak intensity of aromatic and aliphatic regions, % incorporation of styrene content in the polymeric chain is calculated. A detailed description of the analysis and calculation of the molar composition of the copolymers is reported in the literature, <NPL>).

It is seen in the data that the more reactive styrene is incorporated into the copolymer at much higher levels relative to isobutylene and pmStyrene in the feed at elevated temperatures.

The copolymers prepared by the method of the invention may be used to make a variety of derivatives for use in fuel or lubricant additives as well as rubber products, adhesives, sizings and resins such as unsaturated polyester resins or polyurethanes.

<CIT>teaches to prepare alkylated hydroxyl aromatics by reacting polyisobutylene with hydroxyaromatics in the presence of an acidic ion exchange resin. This class of products is useful as lubricant and fuel additive compositions.

<CIT> discloses Mannich fuel additives prepared by reacting alkylated hydroxyaromatic compounds with an aliphatic polyamide and an aldehyde. Mannich reaction product fuel additives are also disclosed in United States Patent Application Publication No. <CIT> wherein the materials are prepared using a mixture of conventional and highly reactive polyisobutylene.

There is seen in United States Patent Application Publication No. <CIT> low molecular weight polyisobutyl-substituted amines as dispersant boosters. Such compounds may be prepared by hydroformylating polyisobutylene followed by reductive amination as is well known in the art.

PIB-maleic anhydride reaction products such as polyisobutenylsuccinic anhydrides (PIBSAs) and polyisobutenylsuccinimides (PIBSIs) are also prepared with the copolymers prepared by the method of the invention:
<CHM>.

As is appreciated from the foregoing, Polyisobutylene Succinic Anhydride (PIBSA) is often used as an intermediate for the synthesis of polyisobutylene succinimide (PIBSI). PIBSA derivatives are prepared via thermal ene reaction with maleic anhydride. It has been found in accordance with the invention that the multiple reactive double bonds in the polyisobutylene isoprene copolymer used to make IP-PIBSA with more than one maleic anhydride attached to the polyisobutylene isoprene copolymer molecule increases the polar to non-polar molecule ratio in the dispersant which has the unexpected and added advantage in dispersing property of the final molecule.

In a parr reactor, using product <NUM> as shown in Table <NUM>, <NUM>:<NUM> molar ratio of product <NUM> and maleic anhydride was added at room temperature. The reaction mixture was stirred for <NUM> minutes and then heated to <NUM> degree Celsius for <NUM> hours to reaction completion. After, excess maleic anhydride was removed using vacuum and reaction product was collected. Product yield was more than <NUM>%. Product made using polyisobutylene isoprene copolymer is higher in viscosity than the one prepared from polyisobutylene succinic anhydride. This is likely due to crosslinking of double bonds at higher temperature. Additional ratios of feed and suitable reaction conditions are noted in the following Table <NUM>.

Exemplary PIBSA and PIBSI compounds are enumerated in <NPL>. Amines may also be prepared from a carbonyl functionalized PIB as described in <CIT>, Col. <NUM>, lines <NUM>-<NUM>. The various derivatives may thus be represented:
<CHM>.

Additional copolymers and derivatives within the purview of the present invention include the following:
<CHM>.

Adhesives are of numerous types, including chemically reactive, for example, epoxy type adhesives or thermoplastic adhesives such as hot melt adhesives or solvent based systems such as polyvinyl acetate emulsions. <NPL>) discloses various methods of epoxidating styrene/butadiene resins which are then blended with epoxy resins of the bisphenol-A type. The epoxidized resins are reported to make the blends more ductile. The reagents used to epoxidize the resins include m-chloroperoxy benzoic acid (MCPBA), peracetic aid (PAA), performic acid (PFA) and hexafluoro isopropanol (HFIP). Terpene resins have been disclosed for use in pressure-sensitive adhesives as tackifiers along with other resins and are reported to increase heat resistance of adhesives. Exemplary compositions might include <NUM>% styrene-isoprene-styrene resin (SIS), <NUM>% limonene resin, naphthenic oil and anti-oxidant.

The polyisobutylene/isoprene or other diene copolymers made by the method of the invention where many of the polymeric chains will have at least two double bonds is used as reactive plasticizer for adhesive formulations. Having multiple double bonds in the polymer chain facilitates crosslinking with pressure sensitive adhesives.

Paper sizing imparts hydrophobicity to paper which is generally very hydrophilic, thus allowing enhanced properties such as inking and water barrier properties. Paper sizing agents typically are of two classes, Alkyl Ketene Dimer (AKD) sizings or Alkyl Succinic Anhydride (ASA) sizings. ASA is typically an alpha olefin product in the range of <NUM>-<NUM> carbons prepared by reaction with maleic anhydride. ASA sizings are thus amphiphilic and reactive allowing integration into the paper via the succinic anhydride end and sizing properties are imparted by the hydrophobic hydrocarbon end. Thus, ASA is subsequently emulsified and added into the papermaking process either at the wet-end or sprayed on the paper web. The copolymers described herein are expected to offer enhanced sizing properties based on multiple succinic anhydride groups per molecule allowing better integration into the paper product and superior sizing properties. Further details are seen in: <NPL>; <NPL>. A detailed discussion of paper sizing compositions, their preparation and use is also found in <NPL>). <CIT> and <CIT> are of interest as well.

Samples of PIB or co-polymer of isobutylene and <NUM> wt % isoprene were maleated using the thermal reaction of addition of maleic anhydride to the reactant at <NUM> for <NUM> hours. The standard sizing agent, dodecanyl succinic anhydride, a <NUM> carbon alkenyl succinic anhydride (ASA), was used as a control in all tests. To make the sizing emulsion using the anhydride sizing agents, <NUM> of the alkylated succinic anhydride was combined with <NUM> <NUM>% starch solution and <NUM> or <NUM> emulsion stabilizing agent, Genapol <NUM>, and the mixture was emulsified (blended) for <NUM> seconds.

No. <NUM> Whatman filter paper (unsized <NUM> samples per treatment group) was tared for untreated weight and then immersed into an emulsion prepared as noted above. Within <NUM> seconds the samples were removed, air dried overnight, and then oven dried (<NUM>) for <NUM> hours. The samples were then weighed for uptake of solids from the emulsion. Details for Examples <NUM> to <NUM>, referred to as Examples A-E and X, appear in Table <NUM> below.

The degree of sizing Hydrophobicity Index, (HI) was determined using a modified Cobb Test as follows: the paper samples were immersed fully in water for <NUM> seconds, then blotted with a blotting towel (new each time), followed by rolling with a <NUM> weight 5X, then weighed immediately to establish the amount of water uptake (n=<NUM>). Note that an untreated control was also used. Water uptake for the samples appears above in Table <NUM> and in <FIG> where water uptake is normalized to grams of treated paper.

A calculated Hydrophobicity Index takes into account the weight of sizing agent per gram of paper used in the test, which is then compared to ASA (ratio of the two) after first normalizing to untreated control. HI> <NUM> means the sample is more hydrophobic than ASA treated. A sample calculation is set forth below:
All paper samples used were substantially the same size, thus equivalent in paper content and weight of paper need not be normalized in the calculation.

A dimensionless hydrophobicity index (HI) is thus calculated as: <MAT> or: <MAT>.

For Sample E, ASA: <NUM> + [(<NUM>/<NUM>) - (<NUM>/<NUM>)] / (<NUM>/<NUM>) = <NUM> or <NUM>%.

For Sample B: <NUM> + [(<NUM>/<NUM>) - (<NUM>/<NUM>)] / (<NUM>/<NUM>) = <NUM> or <NUM>%.

The sample showing the greatest resistance to water uptake was the isoprene-isobutylene random co-polymer reacted with maleic anhydride (IP-PIBSA) with <NUM>. 5X or <NUM>% higher hydrophobicity index than standard ASA. This is indeed a very useful and unexpected result. PIBSA, the homopolymer of PIB reacted with maleic anhydride with or without Genapol, showed similar hydrophobicity indices which were about <NUM>% higher than ASA. The PIB only, without the maleic anhydride reaction, showed hydrophobicity most similar to that of the ASA, showing that the succinic anhydride group on the PIB or the isoprene-PIB is preferred for bonding to the paper and thus hydrophobicity of the paper after sizing. The rank of sizing agents with increasing efficacy (hydrophobicity) is therefore: <MAT>.

It is appreciated from the foregoing data that PIB-Isoprene copolymers are particularly preferred for preparing alkylated succinic anhydride sizing agents and emulsifying them with starch and optionally an additional emulsifier or protective colloid. Such compositions include a succinic anhydride derivative of a PIB-Isoprene copolymer having the features in the foregoing Table 1A, emulsified with starch and optionally including an additional emulsifier or protective colloid selected from one or more of: anionic surfactants such as an alkylbenzenesulfonate, an alkylsulfate, a rosined soap, a polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene alkylphenyl ether sulfonate, polyoxyethylene alkylphenyl ether sulfosuccinate, a polyoxyethylene distyrylphenyl ether sulfate and a polyoxyethylene distyrylphenyl ether sulfosuccinate; nonionic surfactants such as polyethylene oxide, polypropylene oxide, and an alkyl, aryl, alkylaryl or aralkylaryl ester or partial ester, ether, or amide of polyethylene oxide or polypropylene oxide; cationic surfactants such as lauryltrimethylbenzylammonium chloride, stearyltrimethylbenzylammonium chloride, distearyldimethylammonium chloride, alkylbenzyldimethylammonium chloride and alkylpyridinium chloride and the like as well as protective colloids, for instance, casein, lecithin, polyvinyl alcohol, a salt of styrene-maleic anhydride copolymer, a salt of styrene-acrylic acid copolymer, various kinds of modified starches, and the like. The various ranges of features in Table 1A may be combined with each other if so desired, for example the general range for molecular weight may be combined with typical ranges or preferred ranges for molar ratios of repeat units, double bonds per molecule and so forth as is noted above in connection with Table 1A.

The copolymers made by the method of the invention may also be used in connection with preparing various resinous products, including unsaturated polyester resins (UPR). These resins are mostly used with reinforced and non-reinforced material for a wide variety of applications. Fiberglass and other inorganic filler reinforced polyester resins are used in cars, boats, construction, fire retardant resins and in electronic devices. However, non-reinforced polyester resins are used in coating applications. Reinforced polyester resin has increased mechanical properties as compared to the non-reinforced one.

Polyester resins are synthesized by condensation reaction of anhydride or acid and alcohol based functional group. In general, maleic anhydride, phthallic anhydride and <NUM>,<NUM> propane glycol is used for condensation reaction. For fire retardant material, brominated or phosphate derivatives of phthallic anhydride is used. Synthesis of polyester resins using these molecules are mostly brittle in character. To reduce the brittleness and increase the hydrolytic stability of resins, we use polyisobutylene succinic anhydride (PIBSA) or polyisobutylene based copolymer derivatives in place of maleic anhydride to make polyester resins.

In a three neck round bottom flask polyisobutylene succinic anhydride (<NUM> mol), phthallic anhydride (<NUM> mol) and propylene glycol (<NUM> mol) was added. Mixture was heated to <NUM> with continuous stirring for <NUM> hrs. After the completion of condensation reaction, temperature was reduced to <NUM>°C and <NUM> of hydroquinone was added in the polyester resin and diluted with <NUM>-<NUM> wt% of styrene. Usually, methyl ethyl ketone or benzoyl peroxide is used as initiator to cure the polymer. The polyester resins and the styrene solvents react together to crosslink and form the solid resins. Polyester resins are formulated with inorganic filler for various applications.

Maleic Anhydride or (PIBSA) + phthallic anhydride + <NUM>,<NUM> propane glycol → Polyester:
<CHM>.

Polyester + Styrene yields the polyester/styrene resins. See <NPL>). See also <CIT>.

The following polyester resins are readily prepared by way of the above procedure:.

In the above Table, PIBSA (<NUM>) refers to isobutylene homopolymer based anhydride and PIB-IPSA (<NUM>) refers to isobutylene/isoprene copolymer based anhydride, wherein the molecular weight of the copolymer, Mn, is <NUM> Daltons. It will be appreciated from the foregoing that an unsaturated polyester resin may be synthesized to incorporate a low molecular weight polyisobutylene homopolymer or oligomer having a number average molecular weight, Mn, of less than <NUM> Daltons, suitably <NUM> Daltons or less. This is conveniently provided by incorporating succinic anhydrides of oligomers such as triisobutylene or tetraisobutylene during preparation of the resins.

There is thus provided in accordance with the present invention an improvement in unsaturated polyester resin production comprising preparing a succinic anhydride from a polyisobutylene composition and synthesizing the unsaturated polyester resin by reacting the succinic anhydride with a glycol and a diacid or diacid anhydride, wherein the polyisobutylene composition is selected from (i) low molecular weight polyisobutylene homopolymer or oligomer having a molecular weight of less than <NUM> Daltons, suitably from <NUM> to <NUM> Daltons, or an isobutylene copolymer having a molecular weight of less than <NUM> Daltons, suitably from <NUM> to <NUM> Daltons, or (ii) a polyisobutylene copolymer of isobutylene and one or more comonomers selected from isoprene, butadiene, cyclopentadiene, dicyclopentadiene, limonene, substituted styrenes, piperylene and C4 to C10 dienes other than isoprene, butadiene, limonene, cyclopentadiene or dicyclopentadiene wherein the molar ratio of isobutylene derived repeat units to the comonomer derived repeat units is from <NUM>:<NUM> to <NUM>:<NUM> and the isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM>,<NUM> Daltons. The isobutylene copolymer composition may have any of the features noted herein, including without limitation, one or more of the features listed in Table <NUM> below.

To an unsaturated polyester of maleic anhydride, phthalic anhydride, and <NUM>,<NUM> propylene glycol of the class of Example <NUM> (with styrene), <NUM> weight % of polyisobutylene isoprene copolymer (Mn~<NUM>), <NUM>% of cobalt napthenate, <NUM>-<NUM>% of MEKP and <NUM>% of diethyl aniline was added and mixed to make a homogenous solution at room temperature. Subsequently, the resin mixture was cured in an oven at <NUM> degree celsius overnight. A similar experiment was performed with polyisobutylene para-methyl styrene copolymer (Mn~<NUM>). It was found that cured resin with added polyisobutylene isoprene copolymer or polyisobutylene para- methyl styrene copolymer had better mechanical properties (such as izod impact, flexural strength and shrinkage property of resins) than those without added polyisobutylene copolymer. Similar results are seen with low molecular weight PIB copolymer.

To an unsaturated polyester of maleic anhydride, phthalic anhydride, and <NUM>,<NUM> propylene glycol utilized in Example <NUM>, <NUM> weight % of polyisobutylene homopolymer (Mn~<NUM>), <NUM>% of cobalt napthenate, <NUM>-<NUM>% of MEKP and <NUM>% of diethyl aniline was added and mixed to make a homogenous solution at room temperature. Subsequently, the resin mixture was cured in an oven at <NUM> degrees Celsius overnight. A similar experiment was performed with and without addition of polyisobutylene (Mn~<NUM>). It was found that cured resin with added polyisobutylene had better mechanical properties (Izod impact, flexural strength and shrinkage of the resins) than the one without added polyisobutylene.

In another experiment, when more than <NUM>% of polyisobutylene copolymer was used, it led to separation of two layers during curing. Polyisobutylene or polyisobutylene copolymer is preferably employed at relatively low levels, wherein the PIB polymer also acts as a plasticizer in the resins. Depending upon the solubility of the PIB polymer or PIB copolymer in the medium, the amount of PIB polymer or copolymer employed in an unsaturated polyester resin may be higher or lower considering the solubility of the PIB polymer or PIB copolymer; typically in the range of from <NUM>% to <NUM>% of the solids present.

There is thus provided in another aspect of the present invention an improvement in curing unsaturated polyester resin compositions comprising providing an unsaturated polyester resin composition, adding a polyisobutylene composition along with an initiator and optionally one or more copromoters followed by curing the unsaturated polyester composition. The initiator is suitably a peroxide compound such as methyl ethyl ketone peroxide, and the copromoters (accelerators) may be a metal complex such as a metal napthenate or octoate, or an organic compound such as diethyl aniline, N,N dimethylacetoacetamide, or acetoacetanilide. Suitable components are enumerated in <NPL>. See also <CIT>, <CIT> and a product brochure from <NPL>). The polyisobutylene composition is selected from (i) low molecular weight polyisobutylene homopolymer or oligomer having a molecular weight of less than <NUM> Daltons, suitably from <NUM> to <NUM> Daltons, or an isobutylene copolymer having a molecular weight of less than <NUM> Daltons, suitably from <NUM> to <NUM> Daltons, or (ii) a polyisobutylene copolymer of isobutylene and one or more comonomers selected from one or more comonomers selected from isoprene, butadiene, cyclopentadiene, dicyclopentadiene, limonene, substituted styrenes, piperylene and C4 to C10 dienes other than isoprene, butadiene, limonene, cyclopentadiene or dicyclopentadiene wherein the molar ratio of isobutylene derived repeat units to the comonomer derived repeat units is from <NUM>:<NUM> to <NUM>:<NUM> and the isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM>,<NUM> Daltons. The isobutylene copolymer composition may have any of the features noted herein, including without limitation, one or more of the features listed in Table <NUM> below.

Polyisobutylene copolymer based epoxy derivatives are also used for epoxy resins. These may be prepared by way of reacting the copolymers made by the method of the invention with a peroxidizing agent in order to provide epoxidized copolymers in accordance with the following:
<CHM>.

See <CIT> and the references noted above for details.

Polyisobutylene or PIB based copolymers may be functionalized with OH groups and reacted with di or polyisocyanates to make polyurethanes. See <NPL> See also, <CIT>.

The copolymers made by the method of the invention are likewise suitable to improve properties of rubber compositions, such as those comprising butyl rubber, styrene-butadiene rubber (SBR), natural rubber and the like. The copolymers may be used as such or more preferably derivatized to phenolic, succinimide or succinic anhydride form to provide further functionality and compatibility with the rubber composition. Typically, the copolymers made by the process of the invention are used in amounts of from about <NUM> to <NUM> percent by weight of copolymer or copolymer derivative based on the combined weight of the rubber and copolymer or copolymer derivative in the composition. The copolymers of the invention may be used as reactive intermediates that are part of the rubber matrix production process by grafting onto the rubber matrix resin or copolymerizing with the rubber monomers during production of the rubber resin, thereby modifying the mechanical or physical properties of the rubber itself. The copolymers made by the method of the invention may also be compounded into the rubber in connection with curing to improve the mechanical or physical properties, and may be used as a replacement or enhancement for the typically used process (asphalt) oils during cure. Similarly, the copolymers of the invention may be applied after curing a rubber product and reacted with the cured product to improve properties of the product, for example frictional properties.

Due to increased functionality, viscosity and so forth, the copolymers made by themethod of the invention further improve the properties of a rubber product as compared to conventional rubber/polyisobutylene based compositions as are seen in <CIT>and <CIT> The copolymers made by the method of the invention can be tailored to the application. For example, a random or non-random isobutylene/styrene copolymer optionally derivatized to phenolic, succinimide or succinic anhydride form provides a better anchor in the matrix of an SBR system than PIB or other PIB copolymer compositions. So also, the diene copolymers made by the method of the invention are especially useful when used in connection with curing of the rubber product; here again the diene copolymers may be derivatized to phenolic, succinimide or succinic anhydride form.

There is provided in accordance with the present invention a method of making an isobutylene copolymer comprising: (a) providing a reaction mixture to a reactor comprising isobutylene monomer, and one or more comonomers selected from isoprene, butadiene, cyclopentadiene, dicyclopentadiene, limonene, substituted styrenes, piperylene and C4 to C10 dienes other than isoprene, butadiene, cyclopentadiene, dicyclopentadiene, limonene or piperylene as well as a Lewis acid polymerization catalyst, wherein the molar ratio of isobutylene monomer to the comonomer is from <NUM>:<NUM> to <NUM>:<NUM>; (b) polymerizing the reaction mixture while maintaining the reactor at a temperature of from <NUM> to <NUM> and utilizing a reactor residence time of less than <NUM> minutes to produce a crude isobutylene copolymer in a polymerization mixture; and (c) recovering a purified isobutylene copolymer from the polymerization mixture having a molecular weight, Mn of from <NUM> to <NUM>,<NUM> Daltons. Suitable temperatures and residence times which may be selected for the process appear in the following Table <NUM>:.

The conversion of isobutylene monomer is suitably from <NUM>% to <NUM>%, more preferably from <NUM>% to <NUM>% or <NUM>% to <NUM>%, while the conversion of comonomer is suitably from <NUM>% to <NUM>%, more preferably from <NUM>% to <NUM>% or from <NUM>% to <NUM>%.

Polymerization is typically carried out in a loop reactor or in a CSTR. The Lewis Acid polymerization catalyst typically comprises a catalyst including BF<NUM>, AlCl<NUM> or EtAlCl<NUM> and a co-catalyst comprising an alcohol, ether or ester or mixture thereof, most preferably the catalyst comprises BF<NUM> and an alcohol co-catalyst.

Molar ratios of isobutylene to the one or more comonomers is generally from <NUM>:<NUM> to <NUM>:<NUM>, more typically the molar ratio of isobutylene to the one or more comonomers is from <NUM>:<NUM> to <NUM>:<NUM> or from <NUM>:<NUM> to <NUM>:<NUM>. In some preferred embodiments, the molar ratio of isobutylene to the one or more comonomers is from <NUM>:<NUM> to <NUM>:<NUM>. The one or more comonomers may consist essentially of isoprene, or alpha methyl styrene or mixtures thereof, or may consist essentially of butadiene, cyclopentadiene, dicyclopentadiene, limonene, piperylene or mixtures thereof.

The purified copolymer products made by the method of the invention have the features indicated in the Table <NUM> below.

In another aspect of the invention, there is provided an isobutylene copolymer according to claim <NUM> comprising repeat units derived from isobutylene and repeat units derived from isoprene, wherein the molar ratio of isobutylene derived repeat units to the comonomer derived repeat units is from <NUM>:<NUM> to <NUM>:<NUM> and the isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM>,<NUM>. The product may have any of the features noted above and the additional features noted below.

The molar ratio of isobutylene derived repeat units to the comonomer derived repeat units is generally from <NUM>:<NUM> to <NUM>:<NUM>, more preferably from <NUM>:<NUM> to <NUM>:<NUM> or from <NUM>:<NUM> to <NUM>:<NUM>. In some embodiments, the molar ratio of isobutylene derived repeat units to the comonomer derived repeat units is from <NUM>:<NUM> to <NUM>:<NUM>. Most preferably, the isobutylene copolymer is substantially chloride-free.

The isobutylene copolymer made by the method according to the invention may be incorporated into an adhesive composition, a sizing composition, an unsaturated polyester resin, a fuel or lube additive composition, an epoxy resin or a polyurethane resin. It has also been found that an unsaturated polyester resin incorporating low molecular weight polyisobutylene having a number average molecular weight, Mn, of less than <NUM> Daltons especially wherein the polyester resin incorporates a succinic anhydride derivative of a low molecular weight polyisobutylene oligomer selected from triisobutylene and tetraisobutylene.

Among the preferred embodiments of the invention are the following: In a preferred embodiment of the invention the reactor is maintained at a temperature of up to <NUM>, more preferred at a temperature of <NUM> or above, still more preferred at a temperature of <NUM> or above, very preferred at a temperature of <NUM> or above and most preferred at a temperature of at least 20C or above.

In a preferred embodiment of the method of this invention a reactor residence time of <NUM> minutes or less is used.

In another preferred embodiment of the method of this invention the conversion of isobutylene monomer is from <NUM>% to <NUM>%, more preferred from <NUM>% to <NUM>%.

In another preferred embodiment of the method of this inventionthe polymerization is carried out in a loop reactor or in a CSTR.

In another preferred method according to the invention the polymerization catalyst comprises BF3 and an alcohol co-catalyst.

Preferrred is a method according to the invention, wherein the molar ratio of isobutylene to the one or more comonomers is from <NUM>:<NUM> to <NUM>:<NUM>, more preferred from <NUM>:<NUM> to <NUM>:<NUM>.

Preferred is a method according to the invention, wherein the one or more comonomers comprise isoprene or comprise alpha methyl styrene or para methyl styrene.

In another preferred embodiment of the method according to this invention the purified isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM>,<NUM> Daltons, more preferred from <NUM> to <NUM> Daltons.

In another preferred embodiment of the method according to this invention the purified isobutylene copolymer has, on average, from <NUM> to <NUM> double bonds per molecule.

In still another preferred embodiment of the method according to this invention the purified isobutylene copolymer has, on average, from <NUM> to <NUM> vinylidene double bonds per molecule, more preferred from <NUM> to <NUM> vinylidene double bonds per molecule.

In still another preferred embodiment of the method according to this invention the purified isobutylene copolymer has a PDI of from <NUM> to <NUM>.

Preferred is a method according to the invention, further comprising incorporating the copolymer into an adhesive composition, a sizing composition, an unsaturated polyester resin, a fuel or lube additive composition, an epoxy resin, a polyurethane resin or a rubber composition.

Preferred is an isobutylene copolymer, wherein the molar ratio of isobutylene derived repeat units to the comonomer derived repeat units is from <NUM>:<NUM> to <NUM>:<NUM>, and most preferred from <NUM>:<NUM> to <NUM>:<NUM>.

Preferred is an isobutylene copolymer according to the invention, wherein the isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM>,<NUM> Daltons, more preferred from <NUM> to <NUM> Daltons, and most preferred from <NUM> to <NUM> Daltons.

Preferred is an isobutylene copolymer according to the invention, wherein the isobutylene copolymer has a PDI of from <NUM> to <NUM>.

In a preferred isobutylene copolymer according to the invention the isobutylene copolymer has, on average, from <NUM> to <NUM> double bonds per molecule, more preferred from <NUM> to <NUM> double bonds per molecule and most preferred from <NUM> to <NUM> double bonds per molecule.

In a preferred isobutylene copolymer according to the invention the isobutylene copolymer has, on average, from <NUM> to <NUM> vinylidene double bonds per molecule more preferred from <NUM> to <NUM> vinylidene double bonds per molecule and most preferred from <NUM> to <NUM> vinylidene double bonds per molecule.

Preferred is an unsaturated polyester resin incorporating low molecular weight polyisobutylene made by the method of the invention having a number average molecular weight, Mn, of less than <NUM> Daltons.

Also preferred is an unsaturated polyester resin incorporating low molecular weight polyisobutylene made by the method of the invention having a number average molecular weight, Mn, of less than <NUM> Daltons and incorporating a succinic anhydride derivative of a low molecular weight polyisobutylene oligomer selected from triisobutylene and tetraisobutylene.

Preferred is an unsaturated polyester resin, incorporating low molecular weight polyisobutylene made by the method of the invention having a number average molecular weight, Mn, of less than <NUM> Daltons, wherein the polyisobutylene is incorporated in an amount of less than <NUM>% by weight of the composition.

Claim 1:
A method of making an isobutylene copolymer comprising:
(a) providing a reaction mixture to a reactor comprising isobutylene monomer, and one or more comonomers selected from isoprene, butadiene, cyclopentadiene, dicyclopentadiene, limonene, substituted styrenes, piperylene and C4 to C10 dienes other than isoprene, butadiene, cyclopentadiene, dicyclopentadiene, limonene or piperylene as well as a Lewis acid polymerization catalyst,
wherein the molar ratio of isobutylene monomer to the comonomer is from <NUM>:<NUM> to <NUM>:<NUM>;
(b) polymerizing the reaction mixture while maintaining the reactor at a temperature of from <NUM> to <NUM> and utilizing a reactor residence time of less than <NUM> minutes to produce a crude isobutylene copolymer in a polymerization mixture; and
(c) recovering a purified isobutylene copolymer from the polymerization mixture having a molecular weight, Mn, of from <NUM> to <NUM>,<NUM> Daltons,
with the provisos that (i) when the comonomer is isoprene, butadiene or mixtures thereof, the purified isobutylene copolymer has a molecular weight, Mn, of from <NUM> to <NUM> Daltons and (ii) when the comonomer comprises a substituted styrene the purified copolymer has a molecular weight, Mn, of from <NUM> to <NUM> Daltons.