Abstract: A process comprising heating a latex and a colorant, and optionally a wax, and wherein the latex contains a polymer with a Mz value of from about 60,000 to about 150,000.

Abstract: Elastomers which have excellent stability to prevent oxidative, thermal, dynamic, light-induced and/or ozone-induced degradation comprise, as stabilizers, at least one compound of the formula (I): [R—S(═O)m—CH2—CH(OH)—CH2]n—N(R1)2−n—R2, in which R is C4-C20alkyl, hydroxyl-substituted C4-C20alkyl; phenyl, benzyl, &agr;-methylbenzyl, &agr;,&agr;-dimethylbenzyl, cyclohexyl or —(CH2)qCOOR3, and, if m is 0, R may additionally be (a); and, if n is 1 and R4 is hydrogen, R may additionally be R2—R1N—CH2—CH(OH)—CH2—S(═O)m—(CH2)x— or R2—R1N—CH2—CH(OH)—CH2—S(═O)m—CH2—CH2—(OCH2—CH2)y—, R1 is hydrogen, cyclohexyl or C3-C12alkyl, R2 is (b), R3 is C1-C18alkyl, R4 is hydrogen or —CH2—CH(OH)—CH2—S(═O)m—R, X is C1-C8alkyl, Y is C1-C8alkyl, m is 0 or 1, n is 1 or 2, q is 1 or 2, x is from 2 to 6, and y is 1 or 2.

Abstract: Disclosed is a rubber composition for forming a core of a solid golf ball, the composition containing a base rubber (A); a filler (B); an organic peroxide (C); and a dry blend and/or a solvent slurry blend (D) of an unsaturated carboxylic acid metallic salt and a metal-containing organic sulfur compound represented by the following formula (1): (wherein X represents a halogen atom, each of m and n represents an integer of 0 to 5 inclusive, and M represents a divalent metallic atom). The rubber composition exhibits high curing rate, and can be cured within shorter time, whereby productivity of a core can be improved.

Abstract: Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan.

Abstract: The present invention provides a solid golf ball which imparts a superior shot feeling to the golfer and exhibits stabilized repulsion performance when it is hit at any head speed. The solid golf ball of the present invention comprises a core containing at least one layer which is molded by vulcanizing the rubber composition including: (a) a base rubber, (b) a co-crosslinking agent, (c) an organic peroxide, and (d) a bromine-substituted thiophenol compound represented by the formula, or a monovalent or divalent metal salt thereof: (wherein at least one of R1 to R5 is Br).

Abstract: A process comprising heating a latex and a colorant, and optionally a wax, and wherein the latex contains a polymer with a Mz value of from about 60,000 to about 150,000

Abstract: Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan.

Abstract: Aromatic and aliphatic organic thiol compounds are disclosed which can be utilized to plasticize and/or stabilize halogen-containing polymer compositions, especially poly(vinyl chloride) compositions. Compounds of the present invention are utilized in polymers normally susceptible to deterioration and color change, which typically occurs during processing of the polymer or exposure to certain environments.

Abstract: A rubber composition is disclosed wherein the rubber composition contains at least (a) a rubber component; (b) a silica filler; and, (c) at least one thiuram disulfide accelerator, it being provided that diphenyl guanidine is substantially absent in the rubber composition. The compositions may also include suitable amounts of other ingredients such as carbon black, coupling agents, antiozonants, antioxidants, etc.

Abstract: Organic thiol compounds including aromatic, aliphatic, and diester ether compounds containing sulfhydryl groups are disclosed which can be utilized to plasticize and/or stabilize halogen-containing polymer compositions, especially poly(vinyl chloride) compositions. Compounds of the present invention are utilized in polymers normally susceptible to deterioration and color change, which typically occurs during processing of the polymer or exposure to certain environments.

Abstract: Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan.

Abstract: A resin molding having welding properties, flexibility, and shock impact resistance in a balanced manner. The resin molding has a welded seam, consisting of a resin composition, wherein the resin composition comprises (a) a polyphenylene sulfide resin and (b) an olefin based resin: wherein an amount of the (a) polyphenylene sulfide resin and the (b) olefin based resin is 80 weight % or more of the entire resin composition, and the content of the (b) olefin based resin is 10 to 100 parts by weight relevant to 100 parts by weight of the (a) polyphenylene sulfide resin, and wherein the tensile elongation at break is 20% or more.

Abstract: A metal-containing monomer dissolved mixture comprising a reaction product of an inorganic metal compound with a carboxyl group-containing radical polymerizable monomer, an organic solvent including at least an alcohol-based solvent, and water, wherein the water content is from 0.01 to 30% by weight; a metal-containing resin obtained by copolymerizing the metal-containing monomer (A) in this dissolved mixture with the other radical-polymerizable unsaturated monomer (B); an antifouling paint composition obtained by using this metal-containing resin; and an antifouling paint composition comprising a divalent metal-containing resin (C), a compound (D) of R1—SH (wherein, R1 represents an organic group having 1 to 30 carbon atoms.), and copper oxide (E), are disclosed.

Abstract: Flexible and semi-rigid vinyl chloride resin compositions comprising a combination of a latent mercaptan and a zinc salt of oxidized polyethylene (a zinc ionomer) as a heat stabilizer are substantially free from the offensive odor typically associated with mercaptans and are protected during processing by the degradation products of the latent mercaptan and the zinc ionomer. The oxidized polyethylene is split out from the ionomer to act as an adhesion promoter for aqueous inks and paints, and the residual zinc carboxylate functions as a co-stabilizer with the latent mercaptan in the composition. The latent mercaptan is exemplified by a 2-S-(tetrahydropyranyl)thioalkanol., a carboxylic acid ester thereof, a 2-S-(tetrahydropyranyl)thiocarboxylic acid, an ester thereof, and the furanyl homologs of each.

Abstract: Flexible and semi-rigid vinyl chloride resin compositions comprising a combination of a latent mercaptan and a zinc salt of oxidized polyethylene (a zinc ionomer) as a heat stabilizer are substantially free from the offensive odor typically associated with mercaptans and are protected during processing by the degradation products of the latent mercaptan and the zinc ionomer. The oxidized polyethylene is split out from the ionomer to act as an adhesion promoter for aqueous inks and paints, and the residual zinc carboxylate functions as a co-stabilizer with the latent mercaptan in the composition. The latent mercaptan is exemplified by a 2-S-(tetrahydropyranyl)thioalkanol, a carboxylic acid ester thereof, a 2-S-(tetrahydropyranyl)thiocarboxylic acid, an ester thereof, and the furanyl homologs of each.

Abstract: The present invention relates to a stabilizer composition, for use in polyvinyl chloride formulations, which comprises a mixture of: at least one organotin sulfide; at least one organotin chloride; and at least one free mercaptan.

Abstract: A rubber composition is disclosed wherein the rubber composition contains at least (a) a rubber component; (b) a silica filler; (c) a coupling agent; (d) a cure-enhancing amount of at least one polyalkylene oxide; and (e) at least one high molecular weight thiuram disulfide. The compositions may also include suitable amounts of other ingredients such as carbon black, antiozonants, antioxidants, etc.

Abstract: Disclosed herein is a rubber composition comprising: a) a blocked mercaptosilane of a defined structure, wherein the blocking group contains an unsaturated heteroatom or carbon chemically bound directly to sulfur via a single bond and, optionally, may be substituted with one or more carboxylate ester or carboxylic acid functional groups; b) an organic polymer; c) a filler; and d) a deblocking agent.

Abstract: A rubber composition is disclosed wherein the rubber composition contains at least (a) a rubber component; (b) a carbon black filler and (c) an effective amount of a thiuram disulfide accelerator of the general formula 1

Abstract: A composition comprising alkylthio- or aryl(heteroyl)thio-substituted p-phenylenediamine, its method of preparation, and its use as an antidegradant in natural or synthetic rubber.

Abstract: Organic thiol compounds are disclosed which can be utilized to plasticize and stabilize halogen-containing polymer compositions, especially poly(vinyl chloride) compositions. Compounds of the present invention are utilized in polymers normally susceptible to deterioration and color change, which typically occurs during processing of the polymer or exposure to certain environments.

Abstract: Disclosed herein is a rubber composition comprising:

Abstract: The invention relates to a method of enhancing the tear resistance, tensile strength, and the aging properties of a latex product by adding an antioxidant synergist with an antioxidant to a latex compound comprising of a polymer, a stabilizing system, a film surface conditioner and a curing system comprised of an activator, crosslinker and accelerator and to the latex products formed therefrom. Antioxidant synergists which can be used with the present invention include 2-mercaptobenzimidazole (MBI), 2-mercaptotoluimidazole (MTI), zinc 2-mercaptobenzimidazole (ZMBI) and zinc 2-mercaptotoluimidazole (ZMTI). The latex products formed may be gloves but can also include threads, balloons and other latex-related products.

Abstract: An article of manufacture comprises an ultrahigh molecular weight polyethylene (UHMWPE) mixed with a processing oil and a lubricant selected from the group consisting of fatty acid esters, ethoxylated fatty acid esters, glycol esters, PEG esters, glycerol esters, ethoxylated esters, sorbitol esters, ethoxylated sorbitol esters, aromatic ethoxylates, alcohol ethoxylates, mercaptan ethoxylates, modified ethoxylates, amide surfactants, phosphate esters, phosphonate esters, phosphite esters, alkyl sulfates, fatty acid ethers, alkyl ether sulfates, alkylaryl ether sulfates, sulfonates, naphthalene sulfonates, sulfosuccinates, sulfonated esters, sulfonated amides, alkyl ether carboxylates, alkylaryl ether carboxylates, quaternary amines, amino quaternary amines, ethoxylated amines, imidazoline derivatives, betaines, sultaines, aminopropionate, catechol derivatives, saturated fatty acids, unsaturated fatty acids, and combinations thereof. The method for making those articles is also disclosed.

Abstract: A rubber composition is disclosed wherein the rubber composition contains at least (a) a rubber component; (b) a silica filler; (c) a coupling agent; (d) a cure-enhancing amount of at least one polyalkylene oxide; and (e) at least one high molecular weight thiuram disulfide. The compositions may also include suitable amounts of other ingredients such as carbon black, antiozonants, antioxidants, etc.

Abstract: Rubber compositions contain, in addition to synthetic or natural rubber and conventional curing agents, an auxiliary composition containing a titanium or zirconium compound. The compositions are characterized by an enhanced cure rate at elevated temperatures such as would be useful for producing molded articles. At the same time the compositions exhibit an increased shelf life whereby uncured compositions of the invention are stable and can be molded for a considerable period of time even after storage at room temperature. Titanium compounds of the invention have at least one alkoxy group bonded to titanium, and zirconium compounds of the invention have at least one alkoxy group bonded to zirconium. In preferred embodiments, the auxiliary composition contains chelates of the titanium or zirconium compound. In particular, the auxiliary composition enhances the rate of cure at elevated temperature, and retards curing at room temperature.

Abstract: Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan.

Abstract: Halogen-containing polymer compositions containing a heat stabilizer comprising a latent mercaptan, a zinc salt, and a free mercaptan as a separate entity are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan. A free mercaptan is among those products. The separate free mercaptan (i.e., an alien free mercaptan) enhances the activity of the latent mercaptan in a synergistic manner.

Abstract: A blocked mercaptosilane of the structure: G—C(═O)—S—CH2CH2CH2SiX3 is disclosed wherein each X is an independently selected RO— group wherein each R is independently selected from the group consisting of hydrogen, alkyl that may or may not contain unsaturation, alkenyl groups, aryl groups, and aralkyl groups, such moieties other than hydrogen having from 1 to 18 carbon atoms, and G is a monovalent alkyl of from 2 to 12 carbon atoms.

Abstract: Sulfur-vulcanizable elastomeric compounds and pneumatic tire components having improved tensile mechanical and dynamic viscoelastic properties are produced by compounding polymers with silica at a temperature of 165° C. to about 200° C., in the presence of a silica dispersing agent, and a very small amount (e.g., about 0.01% to about 1% by weight, based on the weight of the silica) of a bis(trialkoxysilylorgano) tetrasulfide silica coupling agent.

Abstract: The present invention relates to powdered thermosetting compositions including a binder which comprises a carboxyl group containing amorphous isophthalic acid containing polyester, a carboxyl group containing semi-crystalline polyester, at least 10 parts by weight, based on the total weight of the binder, of a specific glycidyl group containing acrylic copolymer and a curing agent having functional groups reactive with the polyesters' carboxyl groups. The powdered thermosetting compositions are useful for the preparation of powdered paints and varnishes which give low gloss coatings having an outstanding flow, a remarkable weatherability and excellent mechanical properties.

Abstract: A golf ball consisting of a core having a diameter of between about 1.54 and about 1.61 inches and a compression of between about 70 and about 80, the core comprising a polybutadiene rubber having a Mooney viscosity of less than about 50 and a halogenated organosulfur compound, or a salt thereof, present in an amount of at least about 2.

Abstract: A composition for an insulating layer of an electric cable wherein the composition contains an ethylene plastic as the base resin and further contains up to about 5% by weight of additives including antioxidant, and peroxide cross-linking agent. The composition is characterised in that the antioxidant additive includes a compound of the formula (V): R1(—(C+O)O—)k(CH2)1—S—(CH2)m(—OO(C═O)—)nR2 where R1 and R2, which are the same of different, are C7-C23 alkyl, C7-C23 alkenyl, R3—Ar—, Ar—R3—, or AR—, where R3 is C8-C24 alkyl and Ar is c6-c14 aryl; k and n, which are the same of different, are 0 or 1, l and m, which are the same or different, are integers ≧0; with the proviso that the compound is free from phenolic groups; and that the compositions is free from compounds having the formula (VI): R—O—(C═O)—CH2CH2SCH2CH2—(C═O)—O—R where R is a C8-C20 alkyl group.

Abstract: The present invention provides a solid golf ball having exceptional rebound characteristics and flight performance, as well as good shot feel. The present invention relates to a solid golf ball comprising at least one layer of a core, and at least one layer of a cover formed on the core, wherein at least one of the layers of the core is formed by vulcanizing and press-molding a rubber composition comprising a base rubber, co-crosslinking agent, organic peroxide, filler and specific organic sulfur compound which contains substituent groups having a substituent constant of not less than 1.42.

Abstract: The present invention relates to a process for improving the shelf life of a hindered phenol antioxidant comprising the step of intimately mixing the hindered phenol antioxidant with a sulfur-containing peroxide decomposer. The inventors have discovered that mixing the peroxide decomposer with the hindered phenol antioxidant reduces the tendency of hindered phenols to yellow with age. This increases the desirability of the hindered phenol because it will not impart color to polymer systems. The present invention also relates to a composition produced from the process described above, and stabilized compositions and additive packages containing the composition produced from the above-described process.

Abstract: Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan.

Abstract: Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan.

Abstract: Flexible, semi-rigid, and rigid vinyl chloride polymer compositions comprising a latent mercaptan-containing heat stabilizer are substantially free from the offensive odor typically associated with mercaptans and are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. The free mercaptan thus released enhances the activity of metallic-based heat stabilizers such as zinc carboxylates and organotin carboxylates and mercaptides in the polymer composition. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan is selected from the group consisting of a 2-S-(tetrahydropyranyl)-thioalkanol, a carboxylic acid ester thereof, a 2-S-(tetrahydropyranyl)-thioglycolic acid, and an ester thereof.

Abstract: An anionic surfactant having a thermal weight loss initiation temperature of at least 250° C. is incorporated with a thermoplastic resin comprising a graft copolymer formed by graft-polymerizing an ethylenically unsaturated monomer onto a rubber trunk polymer obtained by emulsion polymerization using a carboxylic acid-type surfactant. As a result, it is possible to obtain an antistatic resin composition which can be effectively produced on an industrial scale and can provide a shaped product excellent in permanent antistatic property and free from haze or discoloration even when processed under severe processing conditions.

Abstract: A rubber composition comprising (A) a base rubber, (B) a metal salt of an unsaturated carboxylic acid and/or a mixture of an unsaturated carboxylic acid and zinc oxide, (C) an organic peroxide, and (D) a non-aromatic mercaptan and/or (E) a dialkyl disulfide whose alkyl has 3-10 carbon atoms is suitable for forming center cores of solid golf balls and wound golf balls and one-piece golf balls by a pressure molding process.

Abstract: A method and product which provides a solid, non-powdered homogeneous form to liquid and low melting point solid compounds which facilitates stability, storage, dispersability and handling and which may be added directly to formulations requiring the liquid compound or low melting point solid compound. The liquid or low melting point solid ingredient is combined with a binder which is comprised of at least a wax and thermoplastic polymer. During the method of forming the product, both the binder and the liquid compound (or low melting point solid compound) pass through a liquid phase during which they are mixed. The product is then formed and cooled.

Abstract: Flexible, semi-rigid, and rigid vinyl chloride polymer compositions comprising a latent mercaptan-containing heat stabilizer are substantially free from the offensive odor typically associated with mercaptans and are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. The free mercaptan thus released enhances the activity of metallic-based heat stabilizers such as zinc carboxylates and organotin carboxylates and mercaptides in the polymer composition. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan is selected from the group consisting of a 2-S-(tetrahydropyranyl)-thioalkanol, a carboxylic acid ester thereof, a 2-S-(tetrahydropyranyl)-thioglycolic acid, and an ester thereof.

Abstract: A flame-retardant composition having anti-electrostatic properties is disclosed. The composition contains (co)polycarbonate, a flame retardant selected from a specifically defined group and a polyalkylene ether compound.

Abstract: Polymerization process of unsaturated pefluoromonomers, fluoro-containing monomers and optionally in the presence of hydrogen containing olefins, for obtaining polymers contaning hydrogen and fluorine, which utilizes a microemulsion comprising the following components: (a) water; (b) a fluoropolyoxyalkylene having hydrogen-containing end groups and/or hydrogen-containing repeating units; (c) a fluorine-free organic radicalic initiator for the polymerization of fluoro-containing monomers, soluble in component (B); (d) a fluoro-containing surfactant.

Abstract: The zinc bum experienced during the processing of a composition comprising a halogen-containing polymer and a zinc mercaptoester is eliminated by the addition of an organothio compound selected from dithioglycol, polyformals and polyacetals of said dithioglycol, and a mercaptoalkanol.

Abstract: The invention concerns the use, for increasing the durability of moulds made of silicone elastomer crosslinkable by a poly addition or polycondensation reaction, of additive capable of stabilizing the silicone elastomer constituting the mold with respect to materials to be molded, of an additive selected among: (a) antioxidant additives comprising, in their structure additives containing at least one R—Sq—R′ group in which R and R′ are monovalent hydrocarbon groups with at least 3 carbon atoms or a monovalent hydrocarbon group with an ester bond or R and R′ together form a cycle, q being a whole number between 1 and 3 inclusively, (b) additives inhibitors of free radicals capable, in moulding conditions of generating radicals ═N—O; the invention concerns the synergistic combination of (a)+(b), the synergistic combination of (a) and/or (b) with phosphites (c), except for the use of bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate as only additive in a silic

Abstract: A composition comprising 2-alkylthio- or 2-aryl(heteroyl)thio-substituted p-phenylenediamine, its method of preparation, and its use as an antidegradant in natural or synthetic rubber.

Abstract: Organic thiol compounds are disclosed which can be utilized to plasticize and stabilize halogen-containing polymer compositions, especially poly(vinyl chloride) compositions. Compounds of the present invention are utilized in polymers normally susceptible to deterioration and color change, which typically occurs during processing of the polymer or exposure to certain environments.

Abstract: Composite materials particularly suitable in the dental art as a tooth filling material including a polymer matrix, a metal, metal alloy, metal oxide particulate, or combinations thereof, in the presence or absence of colloidal silica, and a coupling agent to adhere the particulate to the polymer matrix. Adhesion can also be facilitated by cleaning and/or coating the particulates prior to incorporation into the polymer matrix. One or two paste systems of the composition with suitable initiators, accelerators, etc. can be formulated.

Abstract: Compositions comprising halogen-containing polymers such as PVC resins are stabilized against heat by a synergistic combination of a free mercaptan and a metal-based stabilizer and/or a Lewis acid such as zinc chloride.