Abstract: The present invention aims to provide a multimodal polymer of propylene comprising a matrix of semicrystalline polymer and a rubber (D) dispersed in said matrix, the multimodal polymer comprising units derived from propylene of from 85 to 99% by weight and units derived from ethylene or C4 to C10 alpha-olefins of from 1 to 15% by weight. The multimodal polymer has a fraction soluble in xylene XS at a temperature of 25° C. of from 7 to 16% by weight, a melt flow rate MFR2 of from 0.05 to 5 g/10 min, a polydispersity index P1 of from 3.5 to 30, and a tensile modulus TM and XS meeting the relationship TM?2375?46.2 XS. Furthermore, the present invention aims to produce the above-mentioned multimodal polymer in a process comprising several reaction steps or zones. The compositions comprising the multimodal polymer of propylene have excellent stiffness combined with good impact strength at a low temperature.

Abstract: An object is to provide a transmission belt which is restrained from being deteriorated in a high-temperature atmosphere, is excellent in softness in a low-temperature atmosphere, and is hardly worn away. To attain the object, the invention provides a transmission belt made of a rubber composition wherein the ratio by weight of a Ziegler-Natta catalyst type ethylene/?-olefin copolymer rubber, which is an ethylene/?-olefin copolymer rubber obtained by polymerization in the presence of a Ziegler-Natta catalyst, to a metallocene type ethylene/?-olefin copolymer rubber, which is an ethylene/?-olefin copolymer rubber obtained by polymerization in the presence of a metallocene catalyst, is from 50/50 to 90/10.

Abstract: The present invention relates to functionalizing agents that are particularly useful for functionalizing living rubbery polymers to make the polymer more compatible with fillers, such as carbon black and silica. These functionalizing agents are comprised of a boron containing compound having a structural formula selected from the group consisting of: wherein R is selected from the group consisting of hydrogen atoms, alkyl groups and aryl groups, wherein R1, R2, and R3 can be the same or different and are selected from the group consisting of alkyl groups, and aryl groups, and wherein R4 represents an alkylene group or a bridging aromatic group.

Abstract: Disclosed is a thermoplastic elastomer composition containing 10-60 parts by weight of a non-crosslinkable crystalline polyolefin resin (A), 1-30 parts by weight of a specific propylene 1-butene random copolymer (B) and 89-10 parts by weight of an ethylene ?-olefin non-conjugated polyene copolymer rubber (C) which is composed of ethylene, an ?-olefin having 3-20 carbon atoms and a non-conjugated polyene, in such amounts that the total of the components (A), (B) and (C) is 100 parts by weight. The thermoplastic elastomer composition is dynamically crosslinked by an extruder. This thermoplastic elastomer is excellent in moldability and economic efficiency, and enables to obtain a molded body exhibiting sufficient adhesion strength to a vulcanized rubber or thermoplastic elastomer without the intermediation of an adhesive layer, as well as a lightweight molded body having sufficient hardness and rubber elasticity.

Abstract: The present invention has its object to provide a resin composition for tubes excellent in balance among wear resistance, flexibility, gas permeation resistance and low resilience (pliability). The object is accomplished by a resin composition for tubes which comprises an isobutylene block copolymer (A) constituted of a polymer block (a) derived from isobutylene as a main constituent and a polymer block (b) derived from a monomer component other than isobutylene as a main constituent, and a thermoplastic polyurethane resin (B).

Abstract: A method for melt-processing a polymer of a monovinyl aromatic compound, such as styrene, is disclosed. The method may include heating a polymer of a monovinyl aromatic compound volumetrically with microwave energy, wherein the polymer of a monovinyl aromatic compound includes: a discontinuous rubber phase; and a continuous poly(monovinyl aromatic) phase comprising up to 49 weight percent of at least one of an acrylate comonomer and a vinyl cyanide comonomer.

Abstract: A method of modifying the rheology of a thermoplastic resin that includes the steps of providing a thermoplastic resin and blending interpolymer resin particles with the thermoplastic resin. The interpolymer resin contains a styrenic polymer intercalated within a polyolefin, such that the thermoplastic resin is present as a continuous phase and the interpolymer resin is present as a dispersed phase. The method provides a rheology modified thermoplastic resin with improved physical characteristics.

Abstract: The present invention is a rubber modified monovinylidene aromatic polymer composition where the rubber is a sulfanylsilane chain end modified elastomeric polymer. In the present invention the functionalized rubber provides sufficient grafting levels in standard graft polymerization process technologies to prepare desired rubber particle size distributions and morphologies. Across a range of rubber modified monovinylidene aromatic polymers, it has been found that the use of the modified elastomeric polymers according to the present invention can improve the combinations of resin properties, particularly clarity, surface and physical properties, including both rubber modified monovinylidene aromatic homopolymers (e.g., high impact polystyrene and copolymers (e.g., ABS). The functionalized rubbers have sulfanyl functional groups that provide an optimized reactive grafting site.

Abstract: There is provided a rubber composition for a tread having excellent hardness and improving the processability and grip performance of a tire, and a tire comprising thereof. A rubber composition for a tread comprising 30 to 80 parts by weight of silica having a BET specific surface area of less than 150 m2/g and 10 parts by weight or less of carbon black based on 100 parts by weight of a rubber component comprising an epoxidized natural rubber, and a tire comprising thereof.

Abstract: A sealing composition containing a rubber component and polyolefin, wherein the rubber component contains butyl rubber and polyisobutylene having a viscosity average molecular weight in the range of 500,000 to 3,000,000, the mixing ratio of the rubber component to 100 parts by weight of the total amount of the rubber component and the polyolefin is in the range of 40 to 90 parts by weight, and the sealing composition contains 0 to 30 parts by weight of a hygroscopic compound with respect to 100 parts by weight of the total amount of the rubber component.

Abstract: A flexible tubing material includes a radiation crosslinked blend of a first elastomeric polymer including a styrenic thermoplastic elastomer, an ethylene vinyl acetate elastomer, a polyolefin elastomer with a second elastomeric polymer including a polyolefin elastomer, a diene elastomer, or combination thereof, with the proviso that the first elastomeric polymer and the second elastomeric polymer are different. In an embodiment, a method of making a material includes providing the first elastomeric polymer, providing the second elastomeric polymer, blending the first elastomeric polymer and the second elastomeric polymer, extruding or injection molding the blend, and crosslinking the blend with radiation.

Abstract: The present invention is directed to the incorporation of functionalized polyethylenes, in amount of about 1% to 95% by weight based upon the weight of the total crosslinkable material, into ethylene alpha olefin elastomers, such as EPDM elastomer compositions, which are crosslinked by peroxides, which results in improved properties, such as hardness and modulus of elongation, and can result in improved higher abrasion resistance, wear resistance, coefficient of friction, tensile strength, and other properties through a broad temperature range, which are beneficial to power transmission products, such as power transmission belts.

Abstract: This invention relates to a rubber composition having a high storage modulus (G?) and a low loss tangent (tan ?), and more particularly to a rubber composition comprising 2 to 60 parts by mass of a low-molecular weight aromatic vinyl compound-conjugated diene compound copolymer (B) having an aromatic vinyl compound content of 5 to 80% by mass, a vinyl bond content in a conjugated diene compound portion of 5 to 80% by mass, a weight average molecular weight as measured through a gel permeation chromatography and converted to polystyrene of 5,000 to 500,000 and at least one functional group based on 100 parts by mass of a rubber component (A) composed of at least one of natural rubber and synthetic diene-based rubbers.

Abstract: The present invention provides a rubber composition having adequate foamability, uses thereof, a copolymer contained in the rubber composition, a rubber composition capable of providing a cross-linked foam, which has a low specific gravity and an excellent shape-retaining property even when the usage of a nonconjugated polyene is reduced, and a cross-linked rubber and a cross-linked foam, which are produced from the rubber composition.

Abstract: A polyolefin composition comprising, in percent by weight: A) 20-35% of a propylene homopolymer or copolymer with up to 8% of comonomer(s); B) 65-80% of a copolymer of ethylene and (i) propylene or (ii) CH2?CHR alpha-olefins, where R is a 2-8 carbon alkyl radical, or (iii) a combination thereof, optionally with minor amounts of a diene, containing from 40 to less than 54% of ethylene; wherein the weight ratio B/XS of the content B of copolymer component (B) to the fraction XS soluble in xylene at room temperature, both referred to the total weight of (A)+(B), is of 1.25 or less.

Abstract: A curable polymer composition that is quickly curable to form a cured article having excellent adhesion and followability to a substrate and at least including (A) an acrylic copolymer having a hydrogen atom bonded to a silicon atom, (B) a compound having at least two aliphatic unsaturated bonds in one molecule thereof, (C) a fluoroolefin copolymer including vinylidene fluoride as main component, and (D) a catalyst for hydrosilylation reaction.

Abstract: Disclosed is an adhesive composition. The adhesive composition comprises from 30 wt % to 65 wt % of a polyolefin, 15 wt % to 65 wt % of a conjugated diene-based elastomer, 0.5 wt % to 15 wt % of an olefin elastomer, and 0.5 wt % to 25 wt % of a maleated polyolefin. The weight ratio of olefin elastomer to conjugated diene based elastomer is within the range of 0.04 to 1. The adhesive of the invention has improved adhesion to styrenic polymer layer, barrier layer, and polyolefin layer. It is suitable for extruded multilayer films, sheets, and many other related applications.

Abstract: A resin composition for metal plating provides a molded article exhibiting excellent metal plating adhesion strength and chemical resistance, while having excellent productivity. A metal-plated molded article can also be made from such a resin composition. The resin composition for metal plating includes 50-90% by mass of Component (A) and 10-50% by mass of Component (B), the total of Component (A) and Component (B) being 100% by mass, wherein Component (A) is a polypropylene resin, and Component (B) is a rubber-reinforced vinyl resin obtained by polymerizing a vinyl monomer in the presence of a rubber-like polymer, or a mixture of the rubber-reinforced vinyl resin and a (co)polymer of the vinyl monomer. The composition may further include 0.5-30 parts by mass of a compatibilizer (C) per 100 parts by mass of the total of Component (A) and Component (B). Component (B) is preferably a non-diene rubber-reinforced resin.

Abstract: Novel crosslinkable compositions are provided and are based on thermoplastic polymers and elastomers, these compositions comprising, as crosslinking system, specific organic salts of metal ions. Ionically crosslinked thermoplastic elastomers can be obtained therefrom and have excellent physical properties, high-temperature resistance extending above 150° C., and also oil resistance. They can be used for production of moldings.

Abstract: A masterbatch composition comprising (percent by weight): A) 50%-90% of a crystalline polypropylene component comprising: AI) from 25% to 75% of a fraction having a melt flow rate MFRI of from 0.1 to 10 g/10 min.; and AII) from 75% to 25% of a fraction having a melt flow rate value MFRII equal to or lower than 100 g/10 min.; wherein the ratio MFRI/MFRII is from 5 to 60; and B) 10%-50% of a copolymer component of ethylene and at least one C3-C10 ?-olefin, containing from 15% to 50% of ethylene; said masterbatch composition having a value of the intrinsic viscosity [?] of the fraction soluble in xylene at room temperature equal to or higher than 3.5 dl/g, is added to polyolefin materials to obtain final compositions suitable for injection molding.

Abstract: A polyolefin composition comprising an olefin-based thermoplastic elastomer which is superior to conventional olefin-based thermoplastic elastomers in scratch resistance and abrasion resistance and has excellent heat aging resistance is proposed. [Means for Solving the Problem] A polyolefin composition comprising a syndiotactic ?-olefin-based copolymer (A), a polyolefin resin (B) (other than polybutene (C)), polybutene (C), and if necessary, an ethylene-based copolymer rubber (D).

Abstract: A method of preparing a high impact polystyrene comprising contacting styrene monomer, a high cis polybutadiene elastomer, and an initiator under high shear within a reaction zone. A high-impact polystyrene comprising a high cis polybutadiene elastomer. A method of preparing a high impact polystyrene comprising contacting styrene monomer, a high cis polybutadiene elastomer, and an initiator under extreme reaction conditions within a reaction zone.

Abstract: A weatherstrip composition includes the following polymer A group and polymer B group, Polymer A group. A polymer group is made up of a domain 1 consisting of crosslinked product of a polymer selected from a group consisting of ethylene polymer, ethylene/?-olefin copolymer (where the ?-olefin has from 3 to 20 carbons), ethylene/?-olefin/diene copolymer (where the .alpha.-olefin has from 3 to 20 carbons), homopolymer rubber of a conjugated diene monomer, copolymer polymerized with a conjugated diene monomer and an aromatic vinyl monomer, and hydrogenated copolymer polymerized with a conjugated diene monomer and an aromatic vinyl monomer (where the hydrogenation of all double bonds except for the aromatic groups is at least 50%), and a domain 2 is made up of crosslinked product of ethylene polymer or ethylene/?-olefin copolymer (where the ?-olefin has from 3 to 20 carbons).

Abstract: A macromolecule including a polymer and a polyhedral radical chemically bonded to a terminus of the polymer provides numerous processing and performance advantages. Further functionalization of this macromolecule also is described as being advantageous in certain circumstances. Methods of providing, functionalizing, and utilizing the macromolecule also are provided.

Abstract: A homogeneous polymer blend comprises a thermoplastic first polymer having a crystallinity of at least 30%; and a second polymer having a crystallinity of more than 5% and being at least partially cross-linked.

Abstract: An object of the present invention is to provide a rubber composition for a tire, which is, when it is used as a rubber composition for a tire, capable of exhibiting good dry grip properties and excellent grip properties in both a relatively low temperature range and a relatively high temperature range, as well as a tire produced by using the rubber composition. The rubber composition of the present invention contains: a rubber component made of at least one type of diene-based polymer; and a copolymer resin obtained by copolymerizing ?-methylstyrene based monomer and aromatic vinyl monomer.

Abstract: Disclosed are four gel compositions that have improved properties over the prior art. These gels include elastosols, solid rubbery gels, UV cured gels and chemically cured gels. The gels are formed from selectively hydrogenated styrene/diene block copolymers, unhydrogenated styrene/diene block copolymers, and selectively hydrogenated styrene/diene block copolymers that have been maleated.

Abstract: The rubber composition for a tire base tread includes a rubber component containing not less than 15% by weight of a terminal-modified diene rubber having a number average molecular weight prior to modification of 150000 to 400000, a filler, and a compound (vulcanizing agent) represented by the following general formula (1) in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the rubber component: (wherein R represents a benzyl group, and n represents an integer of 3 to 12.

Abstract: This invention relates to a composition comprising (a) from about 5 to about 50 weight % mEPDM; and (b) from about 95 weight % to about 50 weight % of a first mPE, wherein the weight % is based on the total weight of the mEPDM and the mPE. This invention further relates to films and articles made from the compositions and methods of making the compositions, films and articles.

Abstract: Disclosed are polyarylene sulfide compounds and melt-processed shapes therefrom in the form of extruded profiles, tubings, pipes, fibers, monofilaments and films. Embodiments especially adapted from the invention are elongated spooled tubings exhibiting a smooth surface texture, spoolability and chemical resistance. The compounds contain polyarylene sulfide, a highly saturated, hydrogenated (if applicable) nitrile copolymer; and an organofunctional silane. The compounds exhibit spherical microdomains of the nitrile copolymer in diameters ranging from 0.1 ?m-100 ?m.

Abstract: It is to provide a high-elasticity rubber composition having a good workability and an excellent crack resistance while preventing the deterioration of rubber properties by using a vulcanization accelerator having a retarding effect equal to or more than that of DCBS without using a retarder such as CTP possibly causing the deterioration of rubber properties after the vulcanization and problems such as blooming and the like. The rubber composition according to the invention is characterized by comprising a rubber component, a sulfenamide-based vulcanization accelerator represented by a formula (I), trans-polybutadiene and sulfur.

Abstract: The invention relates to functionalized bimodal butadiene-methylmethacrylate impact modifiers. The impact modifiers are especially useful in blends of engineering resins, particularly where the blend contains both functional and non-functional resins. Polycarbonate (PC)/polyethylene terephthalate (PET) blends using the functionalized bimodal butadiene-methylmethacrylate impact modifiers of the invention have excellent low temperature impact performance.

Abstract: The present invention relates to a graft copolymer for a transparent thermoplastic polyurethane resin prepared by graft copolymerization of (a) 50-85 weight % of rubber latex having a multi-layered structure composed of an inner layer and an outer layer comprising a conjugated diene monomer and an ethylenically unsaturated aromatic compound in which the refractive index of the inner layer is greater than that of the outer layer; and (b) 15-50 weight % of a C2-C20 vinyl monomer; a method for making same; and a thermoplastic polyurethane resin composition comprising same having excellent color properties, calendaring properties, low temperature impact strength and transparency.

Abstract: A rubber composition for a tire superior in grip performance and abrasion resistance and a tire prepared by using the same are provided. The rubber composition for a tire comprises 3 to 200 parts by weight of an aromatic vinyl polymer having an end modified with —OH, —SH, —COOH, —CSSH, —SO3H, —(COO)xM, —(SO3)xM or —CO—R (M is a cation, x is an integer of 1 to 3 depending on the valency of M and R is an alkyl group) and having a weight average molecular weight of 300 to 10,000, based on 100 parts by weight of a diene rubber, and the tire is prepared by using the rubber composition.

Abstract: A laser-sinterable resin powder, which retains properties of styrene resins such as impact resistance and low water absorption and shows sharp decrease of melt viscosity similarly to crystalline resins at a temperature not lower than the glass transition temperature can be made of a thermoplastic resin composition containing 10-80 mass % of a crystalline resin (A) with a melting point of 80-250° C. and 20-90 mass % of a styrene resin (B), and having a 50% average particle diameter of 10-100 ?m. The Component (A) is preferably a polyolefin resin. The Component (B) is preferably a rubber-reinforced styrene resin composition, wherein the rubber component is preferably an ethylene-?-olefin copolymer rubber and/or a hydrogenated product of a diene rubber. The laser-sinterable powder preferably has a melt flow rate of 5-500 g/10 min.

Abstract: A heterogeneous polymer blend comprises a dispersed phase comprising a thermoplastic first polymer having a crystallinity of at least 30% and a continuous phase comprising a second polymer different from the first polymer. The second polymer has a crystallinity of less than 20% and is at least partially cross-linked.

Abstract: This invention relates to blends of linear low density polyethylene copolymers with other linear low density polyethylenes or very low density, low density, medium density, high density, and differentiated polyethylenes. The invention also includes articles produced from the linear low density polyethylene and polyethylene blends described.

Abstract: The invention relates to a molded body consisting of plastic with a material thickness of at least 150 $g(m)m at any point. Said body contains a polymer mixture of an impact-resistance modified poly(meth)acrylate plastic, a polymethyl methacrylate matrix, elastomer particles contained in said matrix and a fluoropolymer. According to the invention, the fraction of the fluoropolymer in the mixture is between 30 and 95 wt. % and the polymer mixture of the impact-resistance modified poly(meth)acrylate plastic and the fluoropolymer is present in an outer layer with a continuous material thickness of at least 10 $g(m)m. The invention is characterized in that the impact-resistance modified poly(meth)acrylate plastic consists of between 20 and 70 wt. % poly(meth)acrylate matrix and between 30 and 80 wt. % elastomer particles.

Abstract: The present invention concerns a vulcanizable composition, vulcanized products produced from it, and their use in particular in the production of golf balls or roll coverings.

Abstract: Resin beads having an average particle size of from 0.001 mm to 10 mm and containing a continuous phase and a particulate dispersed phase are described. The continuous phase includes elastomeric polymers; the dispersed phase includes homopolymers and/or copolymers containing repeat units resulting from the polymerization of one or more aryl polymerizable monomers. The unexpanded polymer resin beads can be prepared by dispersing an organic phase containing elastomeric polymers and one or more monomers, into droplets and polymerizing the monomers in the organic droplets in a low shear flow pattern. The beads can be impregnated with blowing agents, expanded and can be used to make molded articles. Resin beads having a continuous phase comprising a nitrile rubber, and a dispersed phase comprising one or more homopolymers and/or copolymers containing repeat units resulting form the polymerization of one or more aryl polymerizable show prolonged retention of blowing agents in unexpanded form.

Abstract: Natural rubber blends, methods for making the same, and articles made therefrom are provided. The natural rubber blend includes at least one propylene copolymer containing ethylene derived units. The natural rubber blend can further include one or more reinforcing fillers, such as carbon black. The presence of the propylene copolymer significantly improves the ozone resistance and ageing properties of the natural rubber gum stock.

Abstract: The invention provides cross-linked polymeric films, laminates, membranes or other polymeric articles, which show rubber like heat resistance (hot set) and dimensional stability above the polymer melting point, while maintaining heat sealing properties. For example, the invention provides a film comprising at least one layer formed from a composition comprising the following components: A) at least one polymer selected from the group consisting of the following: i) an ethylene-based polymer, ii) an ethylene/?-olefin/diene interpolymer, and ii) a C4-C10 olefin-based polymer; B) at least one polymer selected from the group consisting of a propylene/ethylene interpolymer and a propylene/&alpha,- -olefin interpolymer; and wherein the film is crosslinked using radiation and/or chemicals.

Abstract: In a process for producing an elastomer composition, ethylene, at least one alpha-olefin, and at least one diene is contacted with a catalyst system comprising at least two metallocene catalyst compounds and a non-coordinating anion activator wherein one of the metallocene catalyst compounds is an indenyl complex having the general formula: (In1R1m)R3(In2R2p)MXq, and at least one metallocene catalyst compound comprises a compound having the general formula: wherein M is a transition metal from Group 3, 4, or 5 of the Periodic Table of the Elements and other deatures defined herein.

Abstract: A polyolefin composition containing elastomers (plasticizers), crystalline polypropylene, modified by mixing with polybutene-1 and a coupling agent and a bicyclic dicarboxyl acid salt nucleating agent and/or a lubricant which comprises an unsaturated fatty acid ester which acts as a surface modifier in a molded article is described. The composition is adapted to be used with pigments to make finished molded articles which have an appearance of paint covered by a clear coat and which are scratch resistant and have good low temperature (?30° C.) impact properties.

Abstract: The invention provides a composition that contains at least one specific non-crosslinkable organic medium at least one microgel and at least one thickening agent, a process for the preparation thereof and uses of the compositions.

Abstract: In a process for producing a heterogeneous polymer blend, at least one first monomer is polymerized in a first reaction zone in the presence of a supported catalyst to produce a thermoplastic first polymer having a crystallinity of at least 30%. At least part of said first polymer is then contacted with at least one second monomer and at least one polyene in a second reaction zone under conditions sufficient to polymerize said second monomer to produce a second polymer having a crystallinity of less than 20%. The second polymer is at least partially cross-linked in the second reaction zone such that at least a fraction of the second polymer is insoluble in xylene and such that the first and second polymers form different phases of the blend.

Abstract: The present invention relates to a process for preparing a thermoplastic vulcanizate (TPV) comprising: contacting a thermoplastic polymer, a cross-linkable elastomer, at least one curative, and at least one cure activator in a solvent to form Composition A. The solvent is then removed, and thereafter the cross-linkable elastomer is at least partially cured. The average particle size of the cross-linkable elastomer is 10 microns or less after the solvent is removed.

Abstract: In one embodiment is a thermoplastic vulcanizates having improved extrusion properties formed from a composition that includes from 20% to about 80% by weight of an elastomer, from about 80% to about 20% by weight of a thermoplastic, from about 0.05 to about 12 phr of a multifunctional methacrylate monomer peroxide curing coagent; and from about 0.02 to about 6 phr of a phosphorous containing stabilizer. The resultant thermoplastic vulcanizate may be cured with a peroxide curing agent and shows improved die lip build up compared to conventionally prepared thermoplastic vulcanizates. Methods of forming thermoplastic vulcanizates having improved die lip build up are also taught.

Abstract: The present invention provides a crosslinked propylene-based elastomer having an isotactic propylene triad tacticity of from 65 to 95%, a melting point by DSC equal to or less than 110° C., a heat of fusion of from 5 J/g to 50 J/g, and a haze % per 100 mil thickness of 95 or less, and comprising at least 75 wt % propylene-derived units, at least 5 wt % ethylene-derived units, and optionally 10 wt % or less of diene-derived units. In an embodiment, the present invention is a blend of a continuous phase of the crosslinked propylene-based elastomer and a dispersed phase of a crystalline polymeric compound. The present invention also provides elastomeric compositions comprising a crosslinked propylene-based elastomer as described herein and 100 parts by weight or less of a pigment per 100 parts of polymer. The present invention also provides films, fibers, nonwovens, molded objects, and extruded forms which include any of the inventive compositions described herein.

Abstract: The present invention provides a method of manufacturing a stabilized polyacetal resin, comprising the step of applying a heat treatment to a polyacetal resin having an unstable terminal group in the presence of an unstable terminal group decomposer selected from the following Group I, Group II and Group III, thereby decreasing the unstable terminal group: unstable terminal group decomposer of Group I: (I) a quaternary ammonium salt of an acidic cyclic amide compound, unstable terminal group decomposer of Group II: (II) a quaternary ammonium salt of a polycarboxylic acid intramolecularly having four or more carboxyl groups and/or a quaternary ammonium salt of an aminocarboxylic acid intramolecularly having one or more carboxyl group(s), unstable terminal group decomposer of Group III: (III) a quaternary ammonium salt, wherein a compound providing a counter-anion of a quaternary ammonium salt is at least one selected from the group consisting of the following (i) to (v): (i) a carbonic acid monoester