Abstract: A process for producing a vinyl chloride polymer is provided. This process includes polymerizing vinyl chloride or a monomer mixture containing vinyl chloride in an aqueous medium in a polymerization vessel fitted with a reflux condenser. This process is characterized by starting to add (A) an anti-foam agent, and (B) a partially saponified polyvinyl alcohol with an average degree of polymerization of 100 to 500 and a saponification degree of 75 to 85 mole %, to a reaction mixture during the operation of said reflux condenser, and continuing the addition of (A) and (B) until recovery of unreacted monomers from said polymerization vessel is completed. According to the process, it is possible to prevent the polymer slurry from foaming, rising, or scattering during polymerization or recovery of unreacted monomers.

Abstract: A PVC composition for use in cables, particularly computer cables, exhibits improved flame resistant qualities. In addition, the cable includes an outer insulating jacket of a transparent or translucent PVC material, which exhibits a slightly tinted appearance. The PVC material additionally includes reflective particles which provide an aesthetically appealing appearance of the cable.

Abstract: The invention pertains to a process wherein peroxides are dosed to a polymerization mixture, with essentially all of the organic peroxide that is used in the polymerization process having a half-life from 0.05 hour to 1.0 hour at the polymerization temperature. The dosing of such peroxide allows for accurate control of the polymerization rate, and the process will render a polymer with a low residual peroxide level.

Abstract: A graft copolymer composition and the preparation of the composition by living radical polymerization is disclosed. The polymerization reaction can be initiated at active chlorine sites on the poly(vinyl chloride) backbone in conjunction with a transition metal catalyst and an optional ligand. The graft copolymers are useful as, among others, compatibilizers for blends and alloys, as high heat distortion temperature poly(vinyl chloride) materials, as impact modifiers, and permanently plasticized materials.

Abstract: A method of forming a polymer having reactive functionality comprises providing a reaction mixture comprising at least one monomer having at least one reactive functional group and carbon dioxide; and polymerizing the at least one monomer in the reaction mixture to form a polymer having reactive functionality associated with the at least one reactive functional group.

Abstract: The preparation of allylated poly(vinyl chloride) by utilizing an allyltrialkylsilane in the presence of Friedel-Crafts acids is disclosed. The pendant allyl groups can be further reacted through various functionalization reactions to contain end groups such as epoxy and hydroxyl. Alternatively, an unsaturated group can be added to poly(vinyl chloride) utilizing a diene also in the presence of a Friedel-Crafts acid. These pendant groups can also be reacted to contain functional end groups such as hydroxyl and epoxy. In yet a further embodiment, the functionalized end groups such as pendant—OH groups of both the allylated and diene grafted poly(vinyl chloride) are further reacted with other monomers or polymer chains which thus results in a poly(vinyl chloride) chain having pendant monomers or polymers. These compositions are useful as compatibilizers for poly(vinyl chloride) and various other resins.

Abstract: A method of preparing a sterile article is disclosed. A polymer having a halogen-containing repeating unit is prepared that contains about 0.

Abstract: The invention concerns a method for preparation of a liquid polymer composition, where ethylenically unsaturated monomers are polymerized by means of initiators that have a transferable atomic group, and one or more catalysts that contain at least one transition metal, in the presence of ligands that can form a coordination compound with the metallic catalysts, the catalyst is oxidized after the polymerization and then the catalyst is separated by filtration, where the composition contains a solvent with a dielectric constant less than or equal to 4.

Abstract: A method of preparing vinyl chloride resin is provided. In the method, a first vinyl chloride monomer is mixed with a first initiator to prepare a seed polymer particle and a second vinyl chloride monomer and a second initiator are added to the polymerized seed polymer particle. An organic siloxane polymer is added to the first monomer and/or second monomer of Formula (1), wherein R1 is hydrocarbon having 1 to 12 carbon atoms and substituted with a group selected from the group consisting of hydrogen, alkyl, haloalkyl, aryl, haloaryl, aralkyl, polyether, imino, epoxy and vinyl; R2 is saturated hydrocarbon having 1 to 12 carbon atoms; and n is an integer of 10 to 12,000.

Abstract: In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.

Abstract: A process for producing a vinyl chloride polymer, including the steps of (a) subjecting a vinyl chloride monomer alone or a monomer mixture containing a vinyl chloride, to suspension polymerization in water; (b) subjecting the resultant vinyl chloride polymer slurry to stripping to remove an unreacted monomer remaining therein; and (c) dehydrating the polymer slurry having been subjected to stripping. In the polymerization step (a), the ratio of water/monomer is set in a weight ratio of from 0.80 to 1.50, and the viscosity at 20° C. of the polymer slurry to be fed to the stripping step is previously kept adjusted to 0.30 Pa.s or lower. In the stripping step (c), the residual unreacted monomer in the polymer slurry can efficiently be removed using steam in a smaller quantity, thus the vinyl chloride polymer can be produced at a high productivity.

Abstract: A polymerization process for the preparation of (meth)acrylate containing homopolymers or block copolymers comprises heating a mixture of a free radical initiator, a stable free radical agent, and a polymerizable monomer compound to form a thermoplastic resin or resins with a narrow polydispersity. The stable free radical agent is a piperazinone or morpholone based nitroxide or any adducts thereof.

Abstract: The present invention provides a 2,2′-bis(6-benzotriazolylphenol) compound represented by the formula wherein A represents a methylene group or the like, R1 and R5 each represent a hydrogen atom, an alkyl group or the like, R2 represents a hydrogen atom or the like, R3 represents an alkylene group or the like, and R4 represents a hydrogen atom or a methyl group. The compound of the invention is useful as an UV absorber. Further, the compound of the invention can be incorporated into a copolymer by copolymerization with a vinyl monomer, and a polymer composition containing the copolymer can be used as an UV absorber.

Abstract: Chlorinated polyvinyl chloride (CPVC) is prepared from polyvinyl chloride (PVC). When PVC is made utilizing polyvinyl alcohol, the low molecular weight CPVC compound so prepared is colored. A low molecular weight CPVC compound prepared from PVC that was made in the presence of a cellulose ether instead of polyvinyl alcohol resulted in a very low color compound having a DE of O by definition. However, a CPVC compound prepared from PVC made in the presence of polyvinyl alcohol resulted in a relatively high color (DE 18.51). During the polymerization of vinyl chloride, polyvinyl alcohol is replaced with the hydroxypropylmethyl cellulose ether having a methoxyl substitution of 15-35 percent and a hydroxypropoxyl substitution of from 4-35 percent.

Abstract: A vinyl chloride polymer is prepared by charging a reactor with a vinyl chloride monomer, effecting polymerization, removing a slurry of the polymer from the reactor, and washing the reactor interior with water, and repeating the series of steps. The reactor has an internal volume of at least 40 m3. A cylinder-guided lift type washer assembly having a nozzle is secured to the reactor at its top in a sealed manner such that the nozzle can be moved downward and upward in the reactor. Water is fed to the nozzle through the assembly for injecting water from the nozzle into the reactor for cleaning. The large size reactor can be effectively washed with water in the closed state, and vinyl chloride polymers of quality with least fisheyes are produced batchwise, leading to an improved productivity.

Abstract: An apparatus for the intensive degassing of polyvinyl chloride-containing dispersions comprising a polymerization reactor (1), a cooling device (2), and a vacuum unit (3), where the polymerization reactor (1) contains a steam inlet (4) in the lower half, and the polymerization reactor (1), the cooling device (2) and the vacuum unit (3) are connected to one another via a connector (5). The invention also relates to the use of this apparatus and to a process for intensive degassing using this apparatus.

Abstract: The invention is related to an olefin-carbon monoxide-vinyl monomer terpolymer composition which is derived from an olefin feed and a synthesis gas feed and at least one vinyl monomer feed. The invention is also related to a method for preparing olefin-carbon monoxide-vinyl monomer terpolymers by heating an olefin feed, a synthesis gas feed and at least one vinyl monomer feed in the presence of a free radical polymerization initiator. More particularly, the synthesis gas feed comprises predominantly carbon monoxide and hydrogen. The terpolymers of the invention are useful as polyvinyl chloride plasticizers.

Abstract: Disclosed is a method of polymerizing vinyl chloride or vinylidene chloride monomer. A mixture is prepared of (1) a monomer selected from the group consisting of vinyl chloride, vinylidene chloride, and mixtures thereof with up to about 20 wt % of a comonomer, (2) supercritical carbon dioxide, subcritical carbon dioxide, or liquid carbon dioxide in a weight ratio to the monomer of about 0.5 to about 5; and (3) about 0.1 to about 1 phr of a free radical initiator that is soluble in said supercritical carbon dioxide or a solution of said a free radical initiator in a solvent that is miscible with the carbon dioxide. The mixture is heated to a temperature of about 40 to about 70° C. to polymerize the monomer.

Abstract: The dialkyl peroxydicarbonates with short alkyl chains, are used for the aqueous suspension polymerization of vinyl chloride, in the form of a solution in a dialkyl alkanedicarboxylate. The preferred solvents are hexanedicarboxylates (adipates) derived from adipic acid and C6-C10 alkanols. The peroxydicarbonate concentration of the said solutions is generally 15-40% by weight. The process according to the invention produces vinyl chloride polymers of improved quality resulting in shaped articles exhibiting markedly fewer fisheyes. The invention also relates to a two-stage process for the manufacture of a solution of dialkyl peroxydicarbonates with short alkyl chains which is particularly suited for the aqueous suspension polymerization of vinyl chloride. According to this process an inorganic salt is used in the stage of manufacture of the peroxydicarbonate (first stage) and the latter is subsequently isolated by extraction by means of a water-insoluble solvent (second stage).

Abstract: A process for preparing homo- and copolymers of vinyl chloride by batch polymerization in aqueous emulsion in the presence of an emulsifier combination comprising at least two emulsifiers selected from the class consisting of anionic and nonionic emulsifiers, metered in during the polymerization, which comprises metering-in in the first phase of the polymerization, at least one emulsifier of the emulsifier combination having at least 10 carbon atoms, and not starting to meter in the remaining emulsifiers of the emulsifier combination until a polymerization conversion of at least 10% has been reached.

Abstract: This invention relates to a process for the production of lower molecular weight polymers by free radical-initiated polymerization of unsaturated species characterized by the use of an unsaturated compound of Formula I as a chain transfer agent: wherein R1 and R2 are the same or different and are selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted saturated or aromatic carbocyclic or heterocyclic ring, and halogen; X is selected from the group consisting of chlorine, bromine, optionally substituted alkylsulfonyl, and optionally substituted arylsulfonyl, Y is selected from the group consisting of halogen, a polymer chain, and CR3R4Z, wherein R3 and R4 are the same or different and are selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted saturated, unsaturated or aromatic carbocyclic or hetercyclic ring, and halogen; and Z is selected from the group consisting of chlorine, bromine, optionally su

Abstract: A procedure for the production of PVC particles with a narrow size distribution in the range 10-50 &mgr;m, preferably 10-30 &mgr;m, in which, in a first stage, a vinyl monomer or a mixture of monomers is polymerised to form a polymer/oligomer seed particle in the range 1-10 &mgr;m. In a second stage, another vinyl monomer or mixture of monomers is swelled into the polymer/oligomer seed particles and polymerisation takes place in such a way that they grow into polymer particles of the desired size. It is preferable to use aromatic vinyl monomers or acrylates as the monomer in the seed particles. The seed particles in the first stage can be produced in a two-stage swelling process or by dispersion polymerisation.

Abstract: Certain 2,6-pyridinecarboxaldehydebis(imine) and 2,6-diacylpyridinebis(imine) compounds are provided, which are particularly suitable for use as tridentate ligands in iron and cobalt olefin polymerization catalysts.

Abstract: A cast-molding material for a plastic lens which is almost free from causing defective dyeing when dyed, and a process for producing plastic lenses almost free from causing defective dyeing, the cast-molding material containing, as essential components, a combination of (A) diethylene glycol bisallylcarbonate or a mixture of diethylene glycol bisallylcarbonate and a monomer copolymerizable therewith, with (B) a polyether-modified silicone compound, and the process comprising cast-molding the above cast-molding material in a mold.

Abstract: A process for polymerizing a vinyl chloride monomer wherein the vinyl chloride monomer is subjected to homopolymerization or (co)polymerization with a monomer copolymerizable with the vinyl chloride monomer in an aqueous solvent, comprising applying in advance a coating liquid containing a cocondensation product obtained by reacting either a phenothiazine derivative and an aldehyde or a phenothiazine derivative, a naphthol derivative and an aldehyde to give an initial condensation product and then reacting the initial product with a polyphenol, to an inner wall of a polymerization tank and parts of an apparatus in contact with the monomers during the polymerization process. The process makes it possible to apply the cocondensation product as an aqueous solution to, e.g., an inner wall of a polymerization tank; to quite effectively prevent polymer adhesion in, e.g.

Abstract: Disclosed is a method of inhibiting the formation of scale on reactor surfaces in contact with a polymerizing vinyl monomer comprising contacting said monomer with a terpolymer which comprises the condensation reaction product of(A) an aromatic compound that contains the group ##STR1## where Q is OR or SR and R is hydrogen, alkyl from C.sub.1 to C.sub.15, or aryl, alkaryl, or aralkyl from C.sub.6 to C.sub.15 :(B) about 0.1 to about 10 moles of a carbonyl compound per mole of said aromatic compound; and(C) about 0.1 to about 10 moles of a thiourea per mole of said aromatic compound.

Abstract: This process is characterized in that at least one of the said monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension at a temperature which may be as low as 0.degree. C., in the presence of an initiator system comprising at least one radical-generator compound other than an arenesulphonyl chloride; and at least one catalyst consisting of a metal complex represented by the following formula (I): Ma.sub.a (L).sub.n in which: M represents Ni, Pd or Pt; A represents a halogen or a pseudohalide; the groups L are ligands of the metal M, which are chosen independently from those containing at least one from among N, P, As, Sb, and Bi, it being possible for at least two of these ligands to be connected together by one or more divalent radicals; a is an integer from 1 to 5; n is an integer from 1 to 4; with 4.ltoreq.a+n.ltoreq.6, a+n representing the coordination number of the complex.

Abstract: A process is provided for preparing polymer compositions which are multimodal in nature. The process involves contacting, under polymerization conditions, a selected addition polymerizable monomer with a metallocene catalyst having two or more distinct and chemically different active sites, and a catalyst activator.

Abstract: An improved process for producing a polymer by polymerizing a monomer having an ethylenic double bond in a polymerization vessel having a polymer scale preventive coating film on its inner wall surfaces, etc. is provided. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated .pi. bonds and a heterocyclic compound having 5 or more conjugated .pi. bonds, and then coating a second coating liquid on the first layer. The first and second coating liquids are applied by means of steam as a carrier. The second layer has a surface having a contact angle to water of less than 60.degree. after its surface has been brought into contact with a solution of mixture of water and a vinyl chloride monomer in a weight ratio of 1:1, at 50.degree. C. for 1 hour.

Abstract: In a process for recovering low-boiling point substances wherein a low-boiling point substance-containing polymer latex is atomized from a nozzle equipped at the upper part of an evaporator to evaporate the low-boiling point substances, the polymer latex is atomized over the surface of a polymer latex retained in a first evaporator maintained at a pressure of 50 to 130 torr, and then, the polymer latex is atomized over the surface of a polymer latex retained in a second evaporator maintained at a pressure of 100 to 240 torr which is higher than that of the first evaporator; each of the polymer latexes to be atomized in the first and second evaporators is maintained at a temperature of 10 to 30.degree. C. higher than the saturated steam temperature in the respective evaporator. By this process, low-boiling point substances such as unreacted monomer can be recovered with high efficiency from the polymer latex.

Abstract: Disclosed is a method of inhibiting the formation of scale on reactor surfaces in contact with a polymerizing vinyl monomer. The reactor surfaces are contacted with a composition that contains, as a scale reducing agent, an acidic hydrazone condensate or a salt thereof. The scale reducing agent can be added to the polymerizing monomer or it can be placed in a composition containing a surfactant and an inorganic binder and the composition can be applied to the reactor surfaces or added to the monomer.

Abstract: Process for monitoring the quality of latices of halogen-containing vinyl polymers during polymerization in aqueous emulsion, in which a luminous radiation is emitted directly into the aqueous emulsion, the scattered light reflected by the polymer particles of the latex in the spectrum band situated between 1100 and 2500 nm is captured and transmitted to a near-infrared spectrophotometer and is measured at specific wavelengths related by correlation equations to specific properties of the latex which is monitored.Device for monitoring the quality of latices in a reactor during polymerization, including essentially a measuring probe placed in the reactor, an optical coupling of the said probe with a near-infrared spectrophotometer provided with means for emitting light and for capturing the scattered light which is reflected and a computer which has the correlation equations in its memory.

Abstract: A process for the preparation of a resin comprising:heating a mixture of at least one free radical polymerizable monomer, a free radical initiator compound, a stable free radical compound, and a reducing agent.

Abstract: The present invention relates to vinyl chloride copolymers, in the latex form, the particles of which are composed of a core, of an outer layer and optionally of an intermediate layer. It also relates to the process for the manufacture of this latex by seeded miscosuspension polymerization and to its applications in paints and plastisols.

Abstract: At least one of the monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension, at a temperature which may be as low as 0.degree. C., in the presence of at least one radical-generator compound and at least one metal complex catalyst of formula Ma.sub.a (L).sub.n (M=Cu, Ag or Au; A=Hal, pseudohalogen or carboxylate; L=ligands of M chosen from those of formula ##STR1## R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 =H, C.sub.1 -C.sub.10 alkyl, aromatic or heteroaromatic; Z.sup.1, Z.sup.2 and Z.sup.3 =one of the following: ##STR2## (R.sup.7 to R.sup.18 =H, C.sub.1 -C.sub.10 alkyl, aromatic or heteroaromatic; R.sup.19 and R.sup.20 =H, Hal, C.sub.1 -C.sub.10 alkyl, C.sub.1 -C.sub.10 alkoxy or --(CR.sup.21 R.sup.22)rNR.sup.23 R.sup.24, where R.sup.21, R.sup.22, R.sup.23 and R.sup.24 =H,C.sub.1 -C.sub.10 alkyl, aromatic or heteroaromatic, and r=integer from 1 to 10; it being possible also for not more than two from among Z.sup.1, Z.sup.2 and Z.sup.

Abstract: The present invention provides a multi-phase polymerization process for making a water insoluble polymer. The process includes (1) providing a mixture comprising carbon dioxide and an aqueous phase, and containing a monomer and a polymerization initiator, and (2) polymerizing the monomer in the reaction mixture. The monomer may be a hydrocarbon or a fluorinated monomer. The polymerization initiator may be soluble in the aqueous phase, soluble in carbon dioxide, or insoluble in both the aqueous phase and carbon dioxide, such that the initiator forms a separate phase. The present invention also provides multi-phase polymerization reaction mixtures useful in the process of making water insoluble polymers.

Abstract: Novel 1,1,2,2-tetramethylpropylperoxy esters are provided. They are useful as a polymerization initiator in polymerizing vinyl chloride, vinylidene chloride and vinyl acetate monomers, with the advantage of completing polymerization within a short time.

Abstract: A method for the homopolymerization or copolymerization of vinyl chloride, wherein the inner wall of the polymerizer and the like are prevented from being fouled with the resulting polymer by applying a coating fluid containing the oxidative polymerization product of a specific phenolic monomer to the surface of the inner wall of the polymerizer and the like, as well as an anti-fouling agent used for this purpose. The method of this invention can very effectively prevent the polymerizer and the like from being fouled with the resulting polymer without affecting the polymerization rate and various properties of the product. Consequently, the necessity of performing the operation for removal of the deposited polymer after completion of each polymerization cycle is eliminated, thus making it possible to achieve closed polymerization requiring no manhole opening after each polymerization cycle which is becoming increasingly popular in recent years.

Abstract: An improved method is provided for copolymerizing vinyl chloride with allyl glycidyl ether and a vinyl ester. The copolymers so formed include 70-99 weight percent of vinyl chloride, 0.05-15 weight percent of allyl glycidyl ether, and 0.05-15 weight percent of a vinyl ester, preferably vinyl acetate. The copolymers of this invention can be compounded to provide films exhibiting improved heat stability, low haze, and good adhesion to solid surfaces such as glass and metal. The compounded resins thus obtained may be especially advantageously used in forming the interlayer of laminated safety glazings, such as vehicle windshields and architectural glazings.The copolymerization of vinyl chloride, allyl glycidyl ether, a vinyl ester and small amounts of an unsaturated organic trifunctional silane provide self-adhesion without gelation.

Abstract: Novel (2-(1,2-benzisothiazol-3(2H)-ylidene 1,1-dioxide)-2-cyanoacetamido)-phenyl acrylates are disclosed. They are useful in making novel poly?(2-(1,2-benzisothiazol-3(2H)-ylidene 1,1-dioxide)-2-cyanoacetamido)phenyl acrylate! charge-control agents. The charge-control agents are useful for electrostatographic toners and developers.

Abstract: A process is provided for preparing a polymer from an ethylenically unsaturated monomer, wherein the process provides reduced polymer scale deposition both in the liquid-phase region of the polymer vessel and on areas around the interface between the gas phase and the liquid phase, the process involving the use of a polymer vessel having a coating on at least its inner surfaces of a polymer scale preventive film prepared from a polymer scale preventive agent of a salt, either alkali metal, ammonium or both, of a sulfonation product of a condensate prepared from (A) an aromatic amine compound and (B) an aldehyde.

Abstract: A resin composition for low expansion moldings which comprises (A) 20 to 80 parts by weight of a vinyl chloride resin having an average degree of polymerization of from 500 to 1700 and (B) correspondingly from 80 to 20 parts by weight of a copolymer made of 60 to 90 parts by weight a polymerizable monomer mixture consisting of 20 to 40 wt % of acrylonitrile, 20 to 60 wt % of .alpha.-methylstyrene and 20 to 40 wt % of styrene and, correspondingly, 40 to 10 parts by weight of a crosslinked acrylic rubber. The resin composition further comprises (C) 0.5 to 30 parts by weight of an acrylic resin having a reduced viscosity of not less than 3.0 dl/g when measured by use of a chloroform solution of the acrylic resin at a concentration of 0.1 g/100 ml, (D) 0.1 to 10 parts by weight of a thermally decomposable rosining agent, and (E) from 1 to 10 parts by weight of a stabilizer, each based on 100 parts by weight of a mixture of the components (A) and (B).

Abstract: In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.

Abstract: An improved method is provided for copolymerizing vinyl chloride with allyl glycidyl ether and a vinyl ester. The copolymers so formed include 70-99 weight % of vinyl chloride, 0.05-15 weight % of allyl glycidyl ether, and 0.05-15 weight % of a vinyl ester, preferably vinyl acetate. The copolymers of this invention can be compounded to provide films exhibiting improved heat stability, low haze, and good adhesion to solid surfaces such as glass and metal. The compounded resins thus obtained may be especially advantageously used in forming the interlayer of laminated safety glazings, such as vehicle windshields and architectural glazings.

Abstract: A process of polymerizing a monomer capable of undergoing free radical polymerization, comprising contacting the monomer with a diradical initiator at a temperature sufficient to initiate free radical polymerization, wherein said diradical initiator contains sites of C--C unsaturation which cyclize to form a diradical.

Abstract: In preparing a matte vinyl chloride polymer by suspension polymerizing a monomeric charge comprising monomeric vinyl chloride in an aqueous medium, polymerization is started in the presence of 0.05-0.25 part by weight of diallyl phthalate per 100 parts by weight of the monomeric charge, and polymerization is continued while adding 0.01-0.15 part by weight of 1,6-hexanediol di(meth)acrylate per 100 parts by weight of the monomeric charge when the rate of polymerization is in the range of 20-60%. There is produced a matte vinyl chloride-diallyl phthalate copolymer having a tetrahydrofuran-insoluble gel content of 0.5-2.5% by weight in a reproducible manner. A composition prepared by blending the copolymer with a plasticizer has minimized fish-eyes and improved matting effect.

Abstract: A polymerization method carried out in the presence of unsaturated organic peroxide chain transfer agents is disclosed. Also disclosed are (co)polymers and oligomers made by this process and articles of manufacture comprising one or more (co)polymers or oligomers made by this process. Furthermore, the use of these unsaturated organic peroxides as chain transfer agents is disclosed. The present process reduces the severe retardation of polymerization observed for unsaturated organic peroxide chain transfer agents of the prior art and, in some cases, even improves the monomer conversion in comparison to the control.

Abstract: A process for forming dielectric particles includes admixing a vinyl halide monomer and a crosslinker in a liquid dispersion medium to form a first mixture. A second mixture of an initiator and a stabilizer is prepared and added to the first mixture to form a third mixture in which the monomer polymerizes to form white crystalline polymer particles which are sonified for uniformity. The particles may be stained by exposure to a dehydrohalegenation reagent and dispersed in an electrophoretic fluid for use in an electrophoretic display.

Abstract: Vinyl polymers, e.g., the homo- and copolyvinyl chlorides, are prepared in one or more stages, to a degree of conversion of at least 50%, by suspended emulsion polymerizing at least one vinyl monomer, e.g., vinyl chloride, said at least one monomer having dispersed therein finely divided droplets of an aqueous solution of at least one component of a polymerization initiating system, and wherein the amount of water in said aqueous solution constitutes at least 19%, and preferably at least 20% by weight of the at least one monomer.

Abstract: The present invention provides new non-spherical microparticles. The microparticles are a hemisphere or a half elliptic sphere having a big opening at the central portion, say bowl-shape microparticles, and a water uptake of from 80 to 140 ml/100 g, which can be produced by suspension polymerization of polymerizable monomers in the presence of crosslinking agents and hydrophobic liquids in water. The microparticle of the present invention has an excellent extending ability, adhesiveness and water uptake. The new bowl-shape microparticles having the big opening at the center can be easily produced according to the present invention, and the size and shape can be easily controlled.