Abstract: Dandelion processes, compositions and products are provided. One process is a method of preparing dandelion that utilizes a species of a Taraxacum genus, the process including the steps of extracting and recovering a rubber and a carbohydrate from a dandelion root substantially simultaneously. The process employs a dandelion species that is selected from the group consisting of: Taraxacum officianale, Taraxacum kok-saghyz, a rubber-bearing species of the genus Taraxacum, and a combination of two or more thereof. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

Abstract: Cobaloxime derivatives and methods of producing cobaloxime derivatives are disclosed herein. Methods of producing decolorized homo- and co-polymers through polymerization of monomers in presence of the cobaloxime derivatives and decolorization of the produced polymer by exposing the polymer to a sorbent and, optionally, a solvent are also disclosed herein.

Abstract: The present disclosure describes systems and methods that utilize an extendable tracheal tube system. The extendable tracheal tube system includes an extendable tracheal tube having a distal end portion and a proximal end portion. The proximal end portion and the distal end portion of the extendable tracheal tube are capable of moving axially relative to each other. An obturator is also provided that is capable of aiding in the intubation and/or extubation of the extendable tracheal tube. The use of the extendable tracheal tube system and methods enables the secure attachment of the extendable tracheal tube to a patient airway while allowing for certain movements of the patient, such as neck and head movements.

Abstract: Process for obtaining an elastomer in solid phase starting from its polymer solution comprising: 1. a pre- concentration by means of a flash process of the polymer solution; 2. a first removal phase of the vapour by means of an innovative unitary “concentrated stripping” operation; and 3. a final devolatilization of the polymer.

Abstract: Provided by using a catalyst containing an yttrium compound is conjugated diene polymer with very low solution viscosity, improved workability, high degree of branching, and high content of cis-1,4 structures. Also provided is a rubber composition utilizing the polymer and allowing excellent dispersion of reinforcing agent. According to a method of manufacturing a conjugated diene polymer characterized by polymerizing a conjugated diene at 50 to 120° C. in the presence of a catalyst obtained from (A) an yttrium compound, (B) an ionic compound consisting of a non-coordinating anion and a cation, and (C) an organoaluminum compound, the conjugated diene polymer has the following characteristics that: (1) a ratio (Tcp/ML1+4) between a 5 wt % toluene solution viscosity (Tcp) measured at 25° C. and a Mooney viscosity (ML1+4) at 100° C. is 0.1 to 1.2; and (2) a content of cis-1,4 structures is 80% or higher, and a content of 1,2 structures is lower than 5%.

Abstract: Provided herein are polyfarnesenes such as farnesene homopolymers derived from a farnesene and farnesene interpolymers derived from a farnesene and at least a vinyl monomer; and the processes of making and using the polyfarnesenes. The farnesene homopolymer can be prepared by polymerizing the farnesene in the presence of a catalyst. In some embodiments, the farnesene is prepared from a sugar by using a microorganism.

Abstract: A carboxylic acid-modified nitrile copolymer latex is provided. The copolymer latex comprises a carboxylic acid-modified nitrile copolymer of an unsaturated monomer having at least one crosslinkable functional group selected from vinyl and epoxy groups. The use of the copolymer latex enables the production of a molded article that does not undergo long stirring and maturation, causes no allergic reactions due to the absence of sulfur and a vulcanization accelerator, has good oil resistance and high mechanical strength, and produces a soft feeling. Further provided is a latex composition for dip forming comprising the copolymer latex, and an article produced from the latex composition by dip forming.

Abstract: The present invention relates, in part, to high energy processes for manufacturing cross-linked polyolefins. The polyolefins described herein are capable of undergoing further processing without compromising their physical properties and dynamic performance.

Abstract: The present invention relates to a natural rubber that contains 200 ppm or less of phosphorus.

Abstract: The present invention generally relates to a method for sequestering carbon dioxide. Biomass is converted into paraffinic hydrocarbons. The paraffinic hydrocarbons are steam cracked into olefins. The olefins are polymerized into non-biodegradable polyolefins.

Abstract: A structure that comprises a substrate; a cross-linked random free radical copolymer on the substrate; and a self-assembled patterned diblock copolymer film on the random copolymer; wherein the random copolymer is energy neutral with respect to each block of the diblock copolymer film. A method of making the structure is provided.

Abstract: The present invention is directed generally to the use of propylene-based elastomers in articles. The propylene-based elastomers have isotactic polypropylene crystallinity, a melting point by DSC of 110° C. or less, a heat of fusion of from 5 to 50 J/g, and comprise at least 75 wt % propylene-derived units, at least 6 wt % ethylene-derived units, and optionally diene-derived units. The present invention is also directed to processes for making articles comprising propylene-based elastomers.

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: [Issue] To provide an ink sponge and an inkpad employing the same, with which there is little deterioration or loss of ink. [Means of Resolution] An ink sponge which comprises ethylene-propylene-diene rubber sponge. An inkpad comprising a base on which is provided an ink adhesion member for causing ink to adhere thereto, and a lid member, the ink adhesion member comprising ethylene-propylene-diene rubber sponge. The ethylene-propylene-diene rubber sponge can cause ink to adhere thereto but does not absorb the ink.

Abstract: The invention relates to a process for extruding plastic compositions, in particular polymer melts and mixtures of polymer melts, above all thermoplastics and elastomers, particularly preferably polycarbonate and polycarbonate blends, also with the incorporation of other substances such as for example solids, liquids, gases or other polymers or other polymer blends with improved optical characteristics, with the assistance of a multi-screw extruder with specific screw geometries.

Abstract: A method comprising: (a) forming a living liquid polymer, wherein said living liquid polymer is anionically initiated and comprises a cation; (b) adding a functional initiator precursor of the formula FI-H, wherein H is hydrogen and FI is a functional group, said H terminates said living liquid polymer resulting in said liquid polymer having a number average molecular weight of about 20,000 (g/mole) to about 100,000 (g/mole), and said FI and said cation form a functional initiator; (c) adding monomer, wherein said functional initiator initiates anionic polymerization of said monomer; and (d) terminating the polymerization reaction initiated in step (c). Steps (a) through (c) may be conducted in a single reactor, allowing a liquid polymer to be dispersed in a functionalized polymer in a single polymerization step. Thus, the liquid polymer does not have to be handled separately and processing efficiency is improved.

Abstract: The invention provides a copolymer rubber excellent in processability in kneading and processability in extrusion; rubber compositions containing the rubber; and crosslinked moldings of the compositions excellent in sealing properties and shape retention. A random copolymer rubber of ethylene (A), a C3-20 ?-olefin (B) and a nonconjugated polyene (C) which satisfies the following requirements (1) to (5): (1) the structural units (A) and (B) are contained at an (A)/(B) molar ratio of 40/60 to 95/5, (2) the structural unit (C) content is 0.01 to 5% by mole, (3) the limiting viscosity [?] is 1.0 to 5.0 dl/g as determined in decahydronaphthalene at 135°., (4) the Mw/Mn is 1 to 8, and (5) the P value is 0.46 to 1.00 as defined by formula (1): P=Ln(limiting viscosity [?])?5.0×105×?*(10) (1) (wherein Ln is a natural logarithm; and ?*(10) is viscosity (Pa·sec) as determined at 190° C. and at 10 rad/sec.

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 hydrogenated copolymer obtained by hydrogenating an unhydrogenated copolymer comprising conjugated diene monomer units and vinyl aromatic monomer units, the hydrogenated copolymer containing at least one hydrogenated copolymer block (B) which is obtained by hydrogenating an unhydrogenated random copolymer block comprised of conjugated diene monomer units and vinyl aromatic monomer units, wherein the hydrogenated copolymer has the following characteristics: the hydrogenated copolymer has a content of the vinyl aromatic monomer units of from more than 40% by weight to less than 95% by weight; at least one peak of loss tangent (tan ?) is observed at ?10 to 80° C. in a dynamic viscoelastic spectrum obtained with respect to the hydrogenated copolymer; and substantially no crystallization peak ascribed to the copolymer block (B) is observed at ?20 to 80° C. in a differential scanning calorimetry (DSC) chart obtained with respect to the hydrogenated copolymer.

Abstract: The present invention has its object to provide a curable composition which comprises a reactive silyl group-containing organic polymer, does not contain, as a silanol condensation catalyst, any organotin type curing catalyst currently of concern because of the toxic feature thereof, is excellent in surface curability and depth curability and, further, can provide cured products excellent in adhesiveness; the above object can be achieved by a curable composition which comprises: an organic polymer (A) containing a silicon-containing group capable of crosslinking under siloxane bond formation; and a guanidine compound (B-1), as a silanol condensation catalyst (B), represented by the general formula (1): R1N?C(NR12)2??(1) (wherein one of the five R1s is an aryl group and the other four R1s each independently is a hydrogen atom or a hydrocarbon group in which the carbon atom at position 1 is saturated).

Abstract: In an isoolefin-diolefin rubber production process (e.g. a butyl rubber production process), the cold rubber slurry produced in the reaction vessel is transported from the reaction vessel to the flash tank during which time the cold slurry may be expressed to separate at least part of the cold liquid reaction medium from the isoolefin-diolefin rubber. The separated cold liquid reaction medium is transported off stream, for example by a mechanical filter, where it can be recycled back into the reaction vessel and/or where it can be used to cool a feed stream or streams of the reaction components. The isoolefin-diolefin rubber and the residual liquid reaction medium are transported to a flash tank for further processing. The ability to separate and recycle cold liquid reaction medium makes the process more economical.

Abstract: A hydrogenated copolymer obtained by hydrogenating an unhydrogenated copolymer comprising conjugated diene monomer units and vinyl aromatic monomer units, the hydrogenated copolymer containing at least one hydrogenated copolymer block (B) which is obtained by hydrogenating an unhydrogenated random copolymer block comprised of conjugated diene monomer units and vinyl aromatic monomer units, wherein the hydrogenated copolymer has the following characteristics: the hydrogenated copolymer has a content of the vinyl aromatic monomer units of from more than 40% by weight to less than 95% by weight; at least one peak of loss tangent (tan ?) is observed at ?10 to 80° C. in a dynamic viscoelastic spectrum obtained with respect to the hydrogenated copolymer; and substantially no crystallization peak ascribed to the copolymer block (B) is observed at ?20 to 80° C. in a differential scanning calorimetry (DSC) chart obtained with respect to the hydrogenated copolymer.

Abstract: Disclosed is a photosensitive resin composition for flexographic printing plates containing a thermoplastic elastomer (A), a polymer (B) mainly composed of butadiene, a photopolymerizable unsaturated monomer (C) and a photopolymerization initiator (D) (which composition substantially contains no hydrophilic polymers). In this photosensitive resin composition for flexographic printing plates, the number average molecular weight of the polymer (B) is not less than 10,000 and not more than 60,000, and the 1, 2 vinyl content in the total double bonds of the polymer (B) is not more than 25%.

Abstract: A thermoplastic resin composition for a refrigerator according to the present invention can include (A) about 20 to about 40 parts by weight of an acrylonitrile-butadiene-styrene graft copolymer resin prepared by grafting in emulsion polymerization about 60 to about 30% by weight of a monomer mixture comprising a cyanide vinyl compound and an aromatic vinyl compound to about 40 to about 70% by weight of a rubber polymer having an average particle size of about 0.1 to about 0.4 ?m; (B) about 1 to about 20 parts by weight of a styrenic copolymer comprising (b1) about 0 to about 75% by weight of a styrenic copolymer prepared by copolymerizing about 5 to about 20% by weight of a rubber polymer having an average particle size of about 0.

Abstract: The present invention provides 1) a complex comprising a mono-anionictridentate ligand, represented by the following general formula (I); 2) a polymerization catalyst composition, comprising the complex; and 3) a cis-1,4-isoprene polymer, a cis-1,4-butadiene polymer, a cis-1,4-isoprene-styrene copolymer, a cis-1,4-butadiene-styrene copolymer, a cis-1,4-butadiene-cis-1,4-isoprene copolymer, and a cis-1,4-butadiene-cis-1,4-isoprene-styrene copolymer, each of which has high-cis-1,4 content in a micro structure and a sharp molecular-weight distribution.

Abstract: Compositions for bonding substrate surfaces, particularly steel, aluminum, and urethane-primed galvanized steel, are disclosed. Desirably, the compositions include a stable emulsion including: (a) at least one curable (meth)acrylate component; (b) at least three different elastomeric polymers that are soluble and/or partially soluble in the (meth)acrylate component; and (c) optionally at least one elastomeric polymer that is not soluble in the (meth)acrylate component. Methods for preparing and methods for using these compositions also are disclosed.

Abstract: The object of the present invention is to provide a process for industrially advantageously producing a polymer having a high molecular weight and a narrow, monodispersed molecular weight distribution, and more particularly, a block copolymer of an anionic polymerizable monomer and an acrylic monomer. The object of the present invention was able to be achieved by reacting an acrylic monomer with a polymer anion, the terminal of which has been modified by a compound that forms a living carbanion capable of polymerizing an anionic polymerizable monomer by reacting with an anion, but which itself does not polymerize, in the presence of a compound represented by formula (1): (R1)nM (wherein, R1 represents a C1-C20 alkyl group or a C6-C20 aryl group, R1 may be the same or different in the case n is 2 or more, M represents an atom belonging to Group 2, 12 or 13 of the long form of the periodic table, and n represents the valency of M).

Abstract: A multi-functional polymer defined by the formula (Q-R¦n—Z—P2—Y where (Q-R)n is a functionality cluster, Q is a functional group, R is a multi-valent organic group, P2 is a long-chain polymer, n is an integer from about 2 to about 10, Y is a proton, a weak functional group, or a selective functional group, and Z is a branch point where the functionality clusters join the long-chain polymer.

Abstract: The present invention relates to hydrogenated nitrile rubber polymers having lower molecular weights and narrower molecular weight distributions than those known in the art.

Abstract: The present invention is directed to a catalyst system for synthesizing rubbery polymers, such as polybutadiene rubber, styrene-butadiene rubber, isoprene-butadiene rubber, or styrene-isoprene-butadiene rubber, that are amine functionalized and have a high trans microstructure. The catalyst system, in one embodiment, includes (a) an organolithium amine compound, (b) a group IIa metal salt of an amino glycol or a glycol ether, (c) an organoaluminum compound, and optionally (d) an amine compound. The amine functionalized rubbery polymers can be utilized in tire tread rubbers where the rubbery polymers may provide desirable wear properties without substantially sacrificing other performance characteristic(s), e.g., traction properties.

Abstract: The production of a protein free synthetic polyisoprene which has both low levels of chemical impurities and good physical properties has yet to be realized. It has now been envisioned that the use of neodymium catalyzed polyisoprene will offer the combined advantages of both a clean, as well as, high cis-1,4 polymer. Synthesis of polyisoprene rubber using a neodymium based catalyst system is described.

Abstract: Disclosed is a method and apparatus for the extraction of high molecular weight biopolymers from plants. Specifically, invention described herein relates to the commercial processing of plant material, including that from desert plants native to the southwestern United States and Mexico, such as the guayule plant (Parthenium argentatum), for the extraction of biopolymers, including natural rubbers. More specifically, the invention relates to laboratory to commercial scale extraction of high molecular weight biopolymers from plant materials including the chemical and mechanical processing of the plants and purification of the extracted biopolymer.

Abstract: This invention provides a polybutadiene capable of improving wear resistance and resistance to crack growth in a rubber composition and a tire, wherein values of e, f and g derived from the following determinant (I): ( 1.7455 0 - 0.0151 - 0.0454 0.4292 - 0.0129 - 0.007 0 0.3746 ) ? ( log 10 ? ( a / d ) log 10 ? ( a / b ) log 10 ? ( a / c ) ) = ( e f g ) ( I ) (wherein a is a mountain peak value around 1130 cm?1 in a transmittance spectrum through Fourier transform infrared spectroscopy (FT-IR), and b is a valley peak value around 967 cm?1, and c is a valley peak value around 911 cm?1, and d is a valley peak value around 736 cm?1) satisfy relationships of equation (II): (Calculated value of cis-1,4 bond)=e/(e+f+g)×100?99 and equation (III): (Calculated value of vinyl bond)=g/(e+f+g)×100?0.

Abstract: A coating is used to detect a fluid leak.

Abstract: Metal complexes, catalyst compositions containing the metal complexes, and processes for making the metal complexes and the catalyst compositions are described for the manufacture of polymers from ethylenically unsaturated addition polymerizable monomers. The metal complexes have chemical structures corresponding to one of the following formulae: wherein MI and MII are metals; T is nitrogen or phosphorus; P is a carbon, nitrogen or phosphorus atom; groups R1, R2 and R3 may be linked to each other; Y is a divalent bridging group; X, X1, and X2 are anionic ligand groups with certain exceptions; D is a neutral Lewis base ligand; and s, o, k, i, ii, p, m, a, b, c, d, e, t, and y are numbers as further described in the claims.

Abstract: The present invention provides an elastomeric composition processable in a curable, filled rubber formulation. The composition comprises a halogenated interpolymer of a C4 to C7 isoolefin and from 3 to 20 weight percent alkylstyrene and comprising from 0.2 to 2 mole percent haloalkylstyrene, a Mooney viscosity less than 37, a number average molecular weight less than 270,000, a weight average molecular weight less than 470,000, a z-average molecular weight less than 700,000, and a branching index (g?) from 0.4 to 1.1. Also disclosed are a method of making a cured, filled rubber article, comprising compounding the elastomeric composition with filler and curative, processing the compounded composition to form a shape of the article, and curing the composition to obtain the article in the formed shape, as well as a tire comprising an innerliner made by the method.

Abstract: A tread cap composition, in accordance with the principles of the invention, may be a composition resulting from a combination of components including: a conjugated diene-based elastomer; a reinforcing filler; an oil softener; a silane coupling agent; and an ultra high molecular weight polyethylene (“UHMWPE”).

Abstract: A complex compound comprising the skeletal unit of Formula A, wherein the ring represented by C(R1)-A1-A2-(A3)x-C(R2)—C— has delocalised unsaturation and is optionally substituted via one or more of A1, A2 and A3 with atoms or groups selected from hydrogen, alkyl, aryl, halogen, or heterocyclic groups containing at least one N, S or O in a carbon ring; A1, A2 and A3 are selected from carbon, nitrogen or oxygen, R1 and R2 are each selected from chlorine, bromine or iodine; x is zero or 1, O is oxygen, E is nitrogen, phosphorus or arsenic, Q represents a divalent bridging group comprising one or more Group 14 atoms; M is a metal selected from Groups 3 to 7; X represents a monovalent atom or group covalently or ionically bonded to M; L is a mono- or bidentate molecule datively bound to M, y satisfies the valency of M and z is from 0 to 5. The complex can be used to polymerise olefins optionally with organo-A1 or -B compounds as activator.

Abstract: The invention features compositions and methods for producing polymers of isoprene derived from renewable resources such as isoprene produced from cultured cells that use renewable carbon sources. A starting isoprene composition, such as a bioisoprene composition, is distinguished from petroleum based isoprene by the purity profile (such as lower levels of certain C5 hydrocarbons other than isoprene, presence of certain compounds associated with the biological process for production) and the relative content of the carbon isotopes. Polymers obtained by polymerization of such starting isoprene composition according to this invention, such as a polyisoprene homopolymer or a copolymer having repeat units that are derived from isoprene, are distinguishable from isoprene containing polymers from petrochemical resources.

Abstract: The present invention relates to a process and to an apparatus for continuous living polymerization of cationically polymerizable monomers, in which at least three feedstocks are mixed in one or more mixers with microstructures and then polymerized in at least one reaction zone.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of (i) polymerizing conjugated diene monomer by employing a lanthanide-based catalyst to form a reactive polymer, and (ii) reacting the reactive polymer with an azine compound.

Abstract: A method of forming a functionalized polymer, the method comprising reacting a living polymer with a compound defined by the formula where R5 includes a monovalent organic group, R6 independently includes a monovalent organic group, each R7 independently includes hydrogen or a monovalent organic group, each R8 independently includes hydrogen or monovalent organic group, R9 includes a monovalent organic group, M is silicon or tin, and x includes an integer from about 2 to about 10, where R5 and R6 may optionally each independently be alkoxy groups, and where R7, R8, and R9 are non-Zerewitinoff organic groups.

Abstract: Provided herein are farnesene interpolymers derived from a farnesene and at least one vinyl monomer. In certain embodiments, the farnesene is ?-farnesene, ?-farnesene or a combination thereof. In some embodiments, the at least one vinyl monomer is ethylene, an ?-olefin such as styrene, or a substituted or unsubstituted vinyl halide, vinyl ether, acrylonitrile, acrylic ester, methacrylic ester, acrylamide or methacrylamide, or a combination thereof.

Abstract: Provided herein are composition comprising a farnesene interpolymer. The farnesene interpolymer can be derived from a farnesene and at least one vinyl monomer. In some embodiments, the mole percent ratio of the farnesene to the at least one vinyl monomer is from about 1:4 to about 100:1. In certain embodiments, the farnesene is ?-farnesene, ?-farnesene or a combination thereof. In some embodiments, the at least one vinyl monomer is ethylene, an ?-olefin such as styrene, or a substituted or unsubstituted vinyl halide, vinyl ether, acrylonitrile, acrylic ester, methacrylic ester, acrylamide or methacrylamide, or a combination thereof.

Abstract: A thermally stable brominated butadiene copolymer, such as brominated styrene/butadiene block copolymer, brominated random styrene/butadiene copolymer or brominated styrene/butadiene graft copolymer, preparation of the brominated butadiene copolymers, use of the brominated butadiene copolymers as a flame retardant additive and polymeric compositions, both foamed and non-foamed, that incorporate a flame-retarding amount of brominated butadiene copolymer.

Abstract: A cationic polymerization process for isoolefins using a zinc halide initiator. The zinc halide initiator is added to a solution of the isoolefin in a suitable solvent, preferably a halocarbon solvent. Polymerization reactions are normally conducted at temperatures high enough to allow the zinc halide initiator to dissolve in the solution. An alkyl halide activator may optionally be used and is preferably added to the solution prior to the zinc halide initiator. A multiolefin may optionally be present in the solution. The process is particularly useful in the formation of isoolefin homopolymers and co-polymers of isoolefins and multiolefins, such as butyl rubber.

Abstract: Disclosed is a catalyst injection nozzle that comprises an outer tube with an open end, a nozzle tip with a diameter connected to the outer tube open end, an orifice connected to the nozzle tip internal to the outer tube, an internal mixing zone connected to the orifice internal to the outer tube, an inner tube residing within the outer tube further comprising an open end connected to the internal mixing zone, where a steady-state, uniform two-phase flow regime between an atomizing gas and at least one liquid catalyst feed does not form in the internal mixing zone at an atomizing gas to liquid catalyst feed flow ratio of about 0.05 to about 10.

Abstract: A flame retardant molding composition includes a rubber modified aromatic vinyl resin, a polyphenylene ether resin, and a cyclic phosphonate ester compound. A shaped article and an electronic device can be made from the flame retardant molding composition.

Abstract: A polymer composition includes a rubber modified vinyl resin, a polyphenylene ether resin, a cyclic alkyl phosphate compound, and an aromatic phosphate ester. In some embodiments, the cyclic alkyl phosphate compound is able to impart good flame retardancy to the composition and thermal resistance to the polymer composition.

Abstract: 3,4-isoprene-based polymer having high isotacticity can be produced by polymerizing an isoprene compound using a complex represented by the general formula (A) and a catalyst activator: wherein R1 and R2 independently represent an alkyl group, a cyclohexyl group, an aryl group or an aralkyl group; R3 represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an aliphatic, aromatic or cyclic amino group, a phosphino group, a boryl group, an alkylthio or arylthio group, or an alkoxy or aryloxy group; M represents a rare earth element selected from Sc, Y, and La to Lu with promethium (Pm) excluded; Q1 and Q2 independently represent a monoanionic ligand; L represents a neutral Lewis base; and w represents an integer of 0 to 3.