Abstract: A process for producing modified cross-linked polymer particles which comprises polymerizing 0.01 to 900 parts by weight of (B) a monomer component containing 50% by weight or more of at least one member selected from the group consisting of aromatic monoalkenyl compounds, acrylic acid esters, methacrylic acid esters, fluoroalkyl acrylates, fluoroalkyl methacrylates, unsaturated carboxylic acids, conjugated diene compounds, vinyl esters and organosilane compounds in the presence of 100 parts by weight of (A) cross-linked polymer particles obtained by polymerizing a monomer mixture comprising 50% by weight or more of at least one cross-linking monomer selected from the group consisting of divinylbenzene, ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate.

Abstract: A rubber-reinforced vinyl aromatic (co)polymer comprising a polymeric matrix and a rubber phase dispersed and/or grafted in the polymeric matrix and consisting of a mixture of(i) a diene rubber and(ii) a vinyl aromatic monomer/conjugated 1,3-diene linear block copolymer, said block copolymer having a diene content exceeding 80 wt % and, respectively, a vinyl aromatic monomer content of less than 20 wt %.

Abstract: An object of the present invention is to provide a process for producing rubber-modified styrene resins in which a distribution of the diameters of the rubber particles is narrow and the impact resistance is well balanced with the elastic modulus. The constitution thereof is characterized in that an aromatic monovinyl series monomer, a rubbery polymer and a styrene polymer are mixed and dissolved, and the mixed solution is adjusted so that the relation of the content R (wt. %) of the rubbery polymer contained in said mixed solution with the content Ps (wt. %) of the styrene polymer satisfies 0.2<Ps/R<3; the solution is further subjected to pre-heating treatment to maintain the conditions before rubber phase inversion, and then rubber phase inversion is carried out in a plug flow type reactor followed by polymerizing to enhance the polymerization conversion rate in the following plug flow type reactor.

Abstract: Elastic-thermoplastic graft polymers manufactured by radical emulsion polymerization of resin-forming vinyl monomers in the presence of rubber present in latex form with the use of a combination of a peroxide of formula (I) ##STR1## where R.sup.1 signifies alkyl, cycloalkyl and aryl groups with 4 to 20 carbon atoms,X the groups --COOH and --SO.sub.3 H as well as their alkali, alkaline-earth or ammonium salts,n an integer in the range from 1 to 6,A alkylene, cycloalkylene and arylene groups with 6 to 40 carbon atomsand a reducing agent as initiator system, a method for their manufacture and their use as moulding compositions.

Abstract: The present invention is a free radical bulk polymerization process for producing a rubber modified polymer from a vinyl aromatic monomer comprising:polymerizing the vinyl aromatic monomer in the presence of a diene rubber having at least one stable free radical group, under polymerization conditions such that a vinyl aromatic-diene block and/or graft copolymer rubber is formed.

Abstract: ABS type thermoplastic moulding compounds obtainable byA) producing a rubber latex with an average particle diameter d.sub.50 of 30 to 160 nm and a gel content of 75 to 100 wt. %B) emulsion polymerization of an amount of butadiene and optionally up to 50 wt. % (with reference to the total amount of monomer in stage B) of a comonomer in the presence of the rubber obtained in stage A, such that a rubber latex (B) with an average particle diameter d.sub.50 =220 to 330 nm and a gel content of 25 to 70 wt. % is produced,C) emulsion polymerization of 40 to 95 parts by wt. of a mixture of styrene and acrylonitrile, which optionally contains up to 50 wt. % (with reference to the total amount of monomers used in stage C) of one or more comonomers, in the presence of 5 to 60 parts by wt. (with reference to the solids) of the rubber obtained in stage B by introducing the monomer in such a way that 55 to 90 wt.

Abstract: The present invention provides a novel multi-arm block copolymer, a novel pressure-sensitive adhesive made from a multi-arm elastomeric block copolymer, and a novel tape made therefrom. The multi-arm block copolymer has the general structure (A-B).sub.m Y(C-D).sub.n wherein A, B, C and D are polymer segments; Y is a residue of a multifunctional coupling agent; and m and n are the number of arms, where m and n are greater than 0 and the sum of m plus n is at least 3. A comprises a random copolymer of a monoalkenylarene and a conjugated diene; B and C comprise either a homopolymer of a conjugated diene or a polymer of two or more conjugated dienes; D comprises either a homopolymer of a monoalkenylarene or a copolymer of a monoalkenylarene and a conjugated diene wherein the Tg of D is greater than the Tg of A; and the weight percent of monoalkenylarene in the block copolymer is 40% or less.

Abstract: In a process for preparing a styrenic resin, a rubber graft copolymer (A) having a weight average particle size of 0.05-0.8 .mu.m by coagulation and drying of a rubber graft copolymer latex (a). The rubber graft copolymer latex (a) is made from graft polymerization of a vinyl aromatic monomer and a vinyl cyanide monomer in the presence of a butadienic rubber latex. The styrenic resin is then prepared by a continuous bulk or solution polymerization method. The method comprises continuously charging 80 to 45 parts by weight of a vinyl aromatic monomer, 15 to 50 parts by weight of a vinyl cyanide monomer, 0 to 40 parts by weight of a copolymerizable monomer (totally 100 parts by weight of monomers), 0.1 to 6 parts by weight of the rubber graft copolymer based on 100 parts by weight of monomers and 0.

Abstract: Thermoplastic moulding compositions containingA) 5 to 95 parts by wt of at least one particle-shaped graft rubber polymer of the ABS type manufactured by emulsion polymerization, in which the graft rubber particles have such a structure detectable by transmission electron microscope photographs, in which the individual particles contain irregular cell-shaped inclusions of resin-forming polymer and the surface of the particles shows such an irregular toothed structure, that for every particle imaged 5 to 30 of such teeth are present, which are distinguished from an idealized round particle (with a diameter d) by a diameter d+d/x with x=3 to 15,B) 95 to 5 parts by wt of at least one particle-shaped graft rubber polymer of the ABS type manufactured by emulsion polymerization, in which the graft rubber particles have such a structure detectable by transmission electron microscope photographs, in which the individual particles do not have a pronounced inner structure as in A) and possess a round particle shape wit

Abstract: The invention relates to polymer compositions of high impact strength, comprising a vinylaromatic polymer and a rubber, and to a process for their manufacture.These compositions are obtained by virtue of the use of two polybutadienes whose viscosities, measured at 25.degree. C. at a concentration of 5% in styrene, are, respectively, between 120 and 350 centipoises in the case of one and between 30 and 90 centipoises in the case of the other.

Abstract: In a process for preparing a thermoplastic molding material comprising from 80 to 50% by weight of a hard matrix of an anionically polymerized aromatic vinyl compound and from 20 to 50% by weight of a soft phase uniformly distributed in the hard matrix, the percentages being based in each case on the sum of the hard matrix and soft phase, a rubber-elastic block copolymer based on an aromatic vinyl compound and on an alkadiene in a weight ratio of 5:95 to 55:45 is anionically polymerized in a first stage, if desired the living chain ends are capped and the aromatic vinyl compound is polymerized in the presence of the block copolymer with renewed addition of an anionic initiator and while stirring, and the living chain ends are finally (re)closed.

Abstract: A method for modifying polyolefins by grafting with a carboxylic acid, carboxylic acid anhydride or other functionalized monomer in the presence of two additional comonomers, one being an aliphatic diolefin and the other an aromatic vinyl or (meth)acrylate monomer.

Abstract: Thermoplastic moulding compositions comprisingA) 1 to 60 parts by weight of at least one particulate graft rubber polymer of the ABS type which is produced by emulsion polymerisation, in which at least 50% of the graft rubber particles (number) have a structure detectable via transmission electron microscopy photographs in which the individual particles contain irregular cellular inclusions of resin-forming polymer and the surface of the particles has an irregular jagged structure such that 5 to 30 of such peaks are present per depicted particle, which particles differ from an idealised round particle (having a diameter d) by a diameter d+d/x, where x=3 to 15,B) 40 to 99 parts by weight of at least one particulate graft rubber polymer of the ABS type which is produced by solution or bulk polymerisation and which has the morphology which is characteristic of bulk types of ABS, and optionallyC) 0 to 200 parts by weight of at least one thermoplastic, rubber-free resin.

Abstract: A method for coupling a cationic polymer includes forming a reaction mixture of a cationic polymer and a bis(diphenylethylene). The reaction mixture is exposed to a temperature which causes the bis(diphenylethylene) to react with the cationic polymer, thereby coupling to cationic polymer. In another embodiment, the method includes forming a reaction mixture of an oxo-acid and a isopropenyl polyisobutylene. The reaction mixture is exposed to a temperature below about -30.degree. C., whereby the oxo-acid reacts with isopropenyl polyisobutylene, thereby coupling the polymer.

Abstract: High-impact poly(styrene) resins modified with small-particle-size, multi-stage impact modifiers having a crosslinked poly(butadiene) core and a poly(styrene) or other vinylaromatic polymer shell show an improved balance of impact strength, stiffness and surface gloss, and an improved resistance to environmental stress crazing, when compared to conventional high-impact poly(styrene).

Abstract: Moulding compounds the ABS type consisting of at least one resin matrix and a particulate graft-rubber polymer distributed therein and produced by emulsion polymerisation, wherein at least 70% of the graft-rubber particles (number) exhibit a structure of the rubber phase which can be detected by photographs taken with the aid of a transmission electron microscope and in which the individual particles contain irregular cellular inclusions of resin-forming polymer and the surface of the particles exhibits an irregularly jagged structure such that, for each particle illustrated, 5 to 30 of such jagged projections are present which differ from an idealised round particle (with a diameter d) by virtue of a diameter d+d/x with x=3 to 15, as well as a process for the manufacture of said moulding compounds.

Abstract: Elastic-thermoplastic graft polymers manufactured by radical emulsion polymerisation of resin-forming vinyl monomers in the presence of rubber present in latex form with the use of a combination of a peroxide of formula (I) ##STR1## where R.sup.1 signifies alkyl, cycloalkyl and aryl groups with 4 to 20 carbon atoms,X the groups --COOH and --SO.sub.3 H as well as their alkali, alkaline-earth or ammonium salts,n an integer in the range from 1 to 6,A alkylene, cycloalkylene and arylene groups with 6 to 40 carbon atomsand a reducing agent as initiator system, a method for their manufacture and their use as moulding compositions.

Abstract: A recyclable polymer is formed of a plurality of oligomer units obtained by polymerizing a fixed number of monomers, and linkage units for linking the oligomer units through a chemical bond which is different from a bond between monomers constituting the oligomer units, thereby allowing repetitive scission and re-bonding of the linkage units by a predetermined treatment not cleaving the bond between monomers. The recyclable polymer is decomposable into oligomers and the oligomers can be linked again into the original polymer without degrading the quality of the polymer. A process for producing the recyclable polymer, a method for recovering the recyclable polymer, and a method for regenerating the recyclable polymer are also provided.

Abstract: Disclosed is an expanded foamed bead of a rubber-modified styrene polymer, comprising a plurality of closed cells defined by cell walls which constitute a matrix for the bead, wherein each of the cell walls comprises two surfaces separated by a distance equal to the thickness of the cell wall.

Abstract: A process is provided for agglomerating small rubber particles in an aqueous latex to form large rubber particles. The process involves the addition of a water soluble organic acid and a water soluble organic anhydride to the latex prior to agglomeration of the rubber particles to facilitate agglomeration of the rubber particles into large rubber particles which are essentially free of coagulum. The latex of large rubber particles is useful in the preparation of ABS polyblends.

Abstract: A stable partially polymerized syrup comprising dispersed rubber-like composite particles in a resin phase may be converted to a metastable syrup in which the rubber-like composite and resin phases are co-continuous by subjecting the stable syrup to high shear under pressure.

Abstract: Microporous crumbs of a hydrogenated block copolymer, produced by the process comprising feeding a solution of a hydrogenated block copolymer in a hydrocarbon solvent at a concentration of said hydrogenated block copolymer within a range from 5% to 60% by weight into hot water while maintaining the temperature of said solution at 40.degree. C.-150.degree. C., and then steam stripping at a temperature higher than the boiling point of the hydrocarbon solvent or higher than the azeotropic point of the hydrocarbon solvent and water when they form an azeotropic mixture and lower than 150.degree. C.

Abstract: A process is provided for the preparation of tapered copolymers by the nonaqueous dispersion polymerization of a mixture of 30 to 70% by weight of a conjugated diolefin monomer, preferably butadiene, and 30 to 70% by weight of a vinyl substituted aromatic monomer, preferably styrene, in a liquid hydrocarbon dispersion medium with an anionic initiator catalyst system in the presence of a block copolymeric dispersing agent. At least one block of the dispersing agent is prepared prior to the dispersion polymerization reaction and at least one block of the dispersing agent is prepared in situ during the dispersion copolymerization. The block of the dispersing agent that is prepared in situ has the polymer structure of the tapered copolymer.

Abstract: There are herein disclosed an olefin copolymer which comprises an olefin unit and a diolefin unit and in which a weight-average molecular weight is in the range of 200 to 800,000, the content of the diolefin unit is in the range of 0.002 to 30 mol%, and a ratio TUS/DOU between the total content of unsaturated groups observed in a molecular chain (TUS mol%) and the content of the diolefin unit (DOU mol%) is in the range of 0.001 to 200; an olefin graft copolymer obtained by the graft polymerization of this olefin copolymer and an olefin; a hydrogenated olefin copolymer and olefin graft copolymer thereof; and a process for preparing these copolymers.These olefin copolymers are excellent in molding/working properties and have a good thermal stability, transparency and uniformity. Therefore, they are useful as a high-performance VLDPE, LDPE, L-LDPE and HDPE, and further useful as a novel branched propylene polymer, a thermoplastic elastomer, a compatibilizing agent for other resins, and the like.

Abstract: Graft and core-shell copolymers are provided which are useful as binders and are prepared from a peroxy-containing copolymer phase a) wherein the copolymer phase contains 0.01 to 20% by weight of residues of an olefinically di-unsaturated peroxy compound and from 80 to 99.99% by weight of residues of at least one comonomer and a polymer phase b) grafted thereon which is obtained by grafting one or more monomers. A process for preparing the copolymers is also provided.

Abstract: A paint film-protective sheet comprising a supporting substrate having formed thereon a rubber-based pressure-sensitive layer comprising a rubber-based polymer having a low polarity and which does not contain unsaturated bonds or contains a small amount of unsaturated bonds, and a high-polar additive. The paint film-protective sheet can adhere even to a paint film which is liable to cause a poor adhesion by bleeding, etc., without need of applying a cleaning treatment, can maintain the good adhered state over a long period of time, and can be easily peeled cleanly even after adhering for a long period of time.

Abstract: An anionic dispersion polymerization process is described for preparing linear block copolymers containing an odd number of blocks including blocks of polymerized styrenic compound, e.g., styrene, (A blocks) which are the end or terminal blocks of the polymer and which alternate along the polymer chain with elastomeric blocks of polymerized conjugated diene units (B blocks). The process includes initially contacting the total amount of styrenic compound to be utilized in forming the block copolymer under polymerization conditions with an anionic initiator and dispersant in an inert dispersion medium in which the polymer is insoluble and carrying out the process in stages wherein less than the total amount of styrenic compound is allowed to polymerize, alternating with stages wherein amounts of diene are added and allowed to polymerize completely. The addition of diene interrupts the polymerization of styrenic compound due to the greater tendency of diene to polymerize.

Abstract: The high nitrile graft copolymer is provided and a high nitrile resin composition impact modified thereby is also provided. Brittle high nitrile resins can be effectively impact modified by the addition of a high nitrile graft copolymer thereto. The high nitrile graft copolymer contains a rubber substrate and a polymeric graft portion superstrate. The substrate contains high levels of diene and amounts of vinyl cyanide and alkylmethacrylate. The polymeric graft portion (superstate) contains high level of vinyl cyanide and a vinyl aromatic hydrocarbon. The high nitrile resin composition is useful as a resin for making chemical resistant high impact molded articles.

Abstract: A method for preparing blends of a copolymer in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomer in the presence of a randomizer; (2) an initiator and monovinylaromatic monomer; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjuated diene monomers; (5) conjugated diene monomer; and (6) a coupling agent; and the polymodal tapered block copolymers prepared thereby. The copolymers are particularly useful neat or in blends for applications such as packaging and food or drink containers which require transparency and good environmental stress crack resistance.

Abstract: A block copolymer comprises block A containing as a main component thereof a homopolymer consisting of units of a vinylaromatic hydrocarbon (VAH), block B consisting of units of a conjugated diene (CD), and block C consisting of VAH and CD, is represented by General Formulae (I) or (II), and has a structure in which blocks A, B, and C are repeated in the order shown in the General Formulae (I) or (II). The block copolymer contains 15 to 98% by weight of a block consisting of 20 to less than 200 VAH, 10% or less by weight of a block consisting of 200 or more VAH, 1 to 70% by weight of an isolated single VAH, and a block consisting of 2 to less than 20 VAH in an amount to make up the rest, each based on total VAH; 15 to 65% by weight of total VAH; 85 to 35% by weight of total CD; and a number-average molecular weight of 5.times.10.sup.4 to 150.times.10.sup.4.

Abstract: What is claimed is a coherent, elastomeric, solid, free-standing film comprising an organic phase comprising: (a) one or more block copolymer(s) corresponding to the formula:A--B--X.sub.m --(B--A).sub.

Abstract: A low viscosity adhesive composition which comprises:(a) an asymmetric radial block copolymer of a vinyl aromatic hydrocarbon and at least one conjugated diene having from 3 to 6 polymer arms, which:(i) contains from 33 to 85% by weight of polyvinyl aromatic hydrocarbon block/polydiene block copolymer arms and the balance polydiene homopolymer arms,(ii) has vinyl aromatic hydrocarbon blocks with block molecular weights of from 8000 to 30,000,(iii) has conjugated diene blocks in the copolymer arms with a molecular weight of at least 6000, and(iv) has a polyvinyl aromatic hydrocarbon content of from 10 to 40% by weight; and(b) from 20 to 400 parts per hundred parts of polymer of a tackifying resin.The invention also encompasses the polymers used in the adhesive.

Abstract: A method is provided for continuous mass polymerization of acrylonitrile-butadiene-styrene type thermoplastics. The method involves charging a liquid feed comprising a vinylidene aromatic monomer, an unsaturated vinyl nitrile monomer and a synthetic butadiene polymer dissolved therein into a grafting reactor to prereact the liquid mass to form grafted rubber continuous phase polymeric product. The product from the grafting reactor is then charged to a phase inversion reactor where free rigid copolymer in monomer is the only continuous phase, and where dispersed particles of grafted rubber with occluded rigid copolymer and monomer are immediately formed from the product of the grafting reactor. The second polymerization product, which is coming out from the phase inversion reactor, is then charged to a finishing reactor wherein the material is further polymerized to form a third polymerization product which then can be devolatilized to provide a final thermoplastic composition.

Abstract: Aqueous dispersions, and films prepared therefrom, comprising an organic phase of block copolymers and optional extenders wherein the block copolymers corresponds to the formula:A-B-X.sub.m -(B-A).sub.nwherein each A is a polymer block of a monovinylidene aromatic monomer and conjugated dienes, each B is a polymer block of one or more conjugated dienes and, optionally, one or more monovinylidene aromatic monomers, X is the remnant of a multifunctional coupling agent, m is 0 or 1, and n is an integer from 1 to 5. Each A polymer block has a weight average molecular weight from 4,000 to 15,000 Daltons. Each B polymer block has a weight average molecular weight from 20,000 to 200,000 Daltons. The total monovinylidene monomer content is from 6 to 30 percent by weight of the organic phase. The effective phase volume of the A polymer block in the organic phase is from 8 to 20 percent. Thin elastomeric articles prepared from the emulsions have improved tensile strength properties.

Abstract: A process for the preparation of hydrocarbon solutions of monofunctional ether initiators of the following general structure:M--Z--O--C(R.sup.1 R.sup.2 R.sup.3)wherein M is an alkali metal; Z is a branched or straight chain hydrocarbon group which contains 3-25 carbon atoms, optionally containing aryl or substituted aryl groups; and R.sup.1, R.sup.2, and R.sup.3 are independently selected from hydrogen, alkyl, substituted alkyl, aryl or substituted aryl groups, and their employment as initiators in the anionic polymerization of olefin containing monomers in an inert, hydrocarbon solvent comprising reacting an omega-protected-1-haloalkyl with lithium metal dispersion having a particle size between 10 and 300 millimicrons in size, at a temperature between 35.degree. and 130.degree. C. in an alkane solvent containing 5 to 10 carbon atoms.

Abstract: An aqueous dispersion is claimed which is capable of forming a free-standing, coherent, elastomeric, solid film which, after drying and annealing at 80.degree. C. for 30 minutes, demonstrates a tensile strength of about 11.0 MPa or greater wherein the dispersion comprises: I. an organic phase comprising: (a) one or more block copolymer(s) corresponding to the formula A-B-X.sub.m -(B-A).sub.n, wherein each A polymer block consists essentially of a monovinylidene aromatic monomer, having a weight average molecular weight from about 8,000 to about 15,000 Daltons, each B polymer block consists essentially of a conjugated diene and, optionally, a monovinylidene aromatic monomer having a weight average molecular weight from about 30,000 to about 200,000 Daltons, X is the remnant of a multifunctional coupling agent, m is 0 or 1, and n is an integer from 1 to 5, and (b) optionally, an extender for the block copolymer which is compatible with the B block; II. a surfactant; and III.

Abstract: Aqueous dispersions, and films prepared therefrom, comprising an organic phase of block copolymers and optional extenders wherein the block copolymers corresponds to the formula:A--B--X.sub.m --(B--A).sub.nwherein each A is a polymer block of a monovinylidene aromatic monomer and conjugated dienes, each B is a polymer block of one or more conjugated dienes and, optionally, one or more monovinylidene aromatic monomers, X is the remnant of a multifunctional coupling agent, m is 0 or 1, and n is an integer from 1 to 5. Each A polymer block has a weight average molecular weight from 4,000 to 15,000 Daltons. Each B polymer block has a weight average molecular weight from 20,000 to 200,000 Daltons. The total monovinylidene monomer content is from 6 to 30 percent by weight of the organic phase. The effective phase volume of the A polymer block in the organic phase is from 8 to 20 percent. Thin elastomeric articles prepared from the emulsions have improved tensile strength properties.

Abstract: Block copolymers of the structure A-B-C-D of improved processability derived from a vinyl aromatic monomer and a conjugated diene, having a total bound vinyl aromatic content in the range of from 10 to 40 wt %, wherein the conjugated diene has been polymerized in a 1,2 or 3,4 addition in an amount of from 1 to 20% of the total bound conjugated diene, and wherein A represents a predominantly poly(vinylaromatic)block, B represents a predominantly poly(conjugated diene), D represents a predominantly poly(vinylaromatic)block, and C represents a tapered block of the conjugated diene occurring in the block B and a the vinyl aromatic occuring in the block D, wherein the tapering in block C shows an increasing content of vinyl aromatic monomer in the direction to block D, wherein the weight ratio of the conjugated diene occurring in block B and the conjugated diene occurring in block C is in the range of from 5:5 to 9:1, and wherein the total apparent molecular weight of which is in the range of from 130,000 to 300,0

Abstract: A molding of an ABS-based resin is described. Rubber particles located at a depth of 0.5-1.5 .mu.m from a surface of the molding morphologically comprise at least the following two types of particles:(1) A particles having an a/b ratio not greater than 1.5, wherein a and b represent a major axis and a minor axis, respectively, and(2) B particles having an a/b ratio not smaller than 5, wherein a and b have the same meanings as defined abovewhen a section extending at the depth in parallel with the surface of the molding is observed in an electron micrograph taken by the ultrathin sectioning technique. Assuming that the total area of the rubber particles as observed in the electron micrograph is 100%, the total area of the A particles accounts for at least 10% and that of the B particles is in a range of 0.01-90%.

Abstract: The present invention is a process for producing predominately four-armed asymmetric radial block copolymers which contain predominately, on average, two arms which are copolymers of at least one conjugated diene and at least one vinyl aromatic hydrocarbon and two conjugated diene homopolymer or copolymer arms, said process comprising:(a) anionically polymerizing at least one conjugated diene monomer and at least one vinylaromatic hydrocarbon monomer to form a set of living polymer arms,(b) anionically polymerizing at least one conjugated diene monomer to form another set of living polymer arms,(c) coupling the one set of living polymer arms with a coupling agent which is selected from the group consisting of tetramethoxysilane and .gamma.

Abstract: The volume average diameter of relatively large rubber-like composite particles dispersed through out a continuous resin phase may be reduced by subjecting the syrup to a shear field. The application of a uniform shear field generator to the relatively large rubber-like composite particle syrup is particularly desirable since it gives a high degree of control over the size and distribution of the dispersed rubber-like composite phase. As a result it is possible to optimize the particle size distribution in an impact modified thermoplastic and obtain better or a better balance of properties.

Abstract: A rubber composition comprised of elastomer, silica, a silica coupler, 2-mercaptobenzothiazole and, optionally, carbon black, in which the silica, silica coupler and at least a portion of the 2-mercaptobenzothiazole are added in a non-productive mix stage.Pneumatic tires having treads comprised of such rubber composition are provided.

Abstract: Disclosed is an expanded foamed bead of a rubber-modified styrene polymer, comprising a plurality of closed cells defined by cell walls which constitute a matrix for the bead, wherein each of the cell walls comprises two surfaces separated by a distance equal to the thickness of the cell wall.

Abstract: A post inversion metastable syrup comprising a continuous or co-continuous rubber like composite phase and a discontinuous or co-continuous resin phase may be particulated by the application of a shear field to yield a stable syrup comprising a dispersed rubber-like composite phase and a continuous resin phase. The application of a uniform shear field to the post inversion metastable syrup is particularly desirable since it results in a high degree of control over the size and distribution of the dispersed rubber-like composite phase. As a result it is possible to optimize the particle size distribution in an impact modified thermoplastic and obtain better or a better balance of properties. The present invention also provides in cooperating arrangement reactors or devices to produce a post inversion metastable syrup, a device to subject the roetastable syrup to a shear field and a polymerization plant.

Abstract: Block copolymers of the structure A-B-C-D of improved processability derived from a vinyl aromatic monomer and a conjugated diene, having a total bound vinyl aromatic content in the range of from 10 to 40 wt.

Abstract: Impact modified resin compositions are provided containing bi-lobed graft copolymers. The lobed graft copolymers contain a rigid lobe and a rubbery lobe. The rubber lobes exhibit an affinity for each other and tend to agglomerate during compounding resulting in large rubber particle sizes which provide the compositions with reduced gloss. The resin compositions are useful as molding resins.

Abstract: High impact polystyrene resins are provided having a surprisingly good combination of toughness and gloss characteristics. Such resins contain small (i.e., 0.1 to 0.4 micron) capsule morphology rubber particles in combination with relatively small (i.e., 0.25 to 1 micron) entanglement morphology rubber particles. It has been found that such resins are capable of providing Izod impact strength values in the range of 2.5 to 3.5 ft-lb/in (133.4 to 186.7 J/m) and higher at an overall volume average rubber size of less than 0.4 micron with corresponding gloss values in excess of 90 percent.

Abstract: Disclosed are a rubber-modified polystyrene resin composition which comprises a polystyrene resin serving as a matrix and soft component particles as dispersed therein, the composition fulfilling the following requirements (a) to (d):(a) the polystyrene resin as the matrix satisfies the following requirements:150,000.ltoreq.Mw.ltoreq.500,000wherein Mw is the weight average molecular weight, and2.ltoreq.Bn(Mz).ltoreq.20wherein Bn(Mz) is the branch count or the number of branching points in the Z-average molecular weight (Mz),(b) the soft component particles in the composition have an average particle diameter (Dp) of 0.1 to 10 .mu.m,(c) the soft component particles in the composition have a swelling index in the range of 3 to 30, and(d) the proportion of the soft component particles in the composition is in the range of 5 to 30% by weight, as well as an injection-molded article formed from the composition.

Abstract: Disclosed are a rubber-modified polystyrene resin composition which comprises a polystyrene resin serving as a matrix and soft component particles as dispersed therein, the composition fulfilling the following requirements (a) to (d):(a) the polystyrene resin as the matrix satisfies the following requirements:150,000.ltoreq.Mw.ltoreq.500,000wherein Mw is the weight average molecular weight, and2.ltoreq.Bn(Mz).ltoreq.20wherein Bn(Mz) is the branch count or the number of branching points in the Z-average molecular weight (Mz),(b) the soft component particles in the composition have an average particle diameter (Dp) of 0.1 to 10 .mu.m,(c) the soft component particles in the composition have a swelling index in the range of 3 to 30, and(d) the proportion of the soft component particles in the composition is in the range of 5 to 30% by weight, as well as an injection-molded article formed from the composition.

Abstract: Novel star-branched polymers in which the arms are each a polymer of an anionically polymerizable monomer consisting of monoethylenically unsaturated compounds comprising p-tert-butylstyrene (t-BS) coupled with a polyalkenyl coupling agent. Certain of the foregoing star-branched polymers, e.g., wherein the arms are a homopolymer of t-BS and the coupling agent is divinylbenzene (DVB), are useful as additives to functional fluids, particularly hydrocarbon lubricating oils, for the purpose of improving their viscometric properties.