Abstract: Process for the preparation of polyvinylarene polymer particles by suspension polymerization, wherein (a) vinylarene monomers are suspended in an aqueous medium to yield a suspension; (b) the temperature of the suspension is adjusted to a temperature above 50° C., at which temperature an initiator is added; (c) subsequently, the reaction temperature is increased by 5 to 30° C. per hour until a temperature of at least 120° C. has been reached; and (d) the temperature is retained at a temperature of at least 120° C. until the polymerization is complete.

Abstract: A process, particularly a gas phase fluidised bed process, for the production of polymers avoids formation of sheets or chunks within the reactor, without the need to use antistatic agents, which can reduce the activity of the catalyst or alter the characteristics of the yielded product. According to the invention, a device generates a corona discharge in the polymerisation reactor during the polymerisation process; an AC voltage difference is applied between the elements which constitute the discharging pair of the device.

Abstract: This composition, which is useful as a binder in the preparation of synthetic resin concretes or mortars, bonding primers or finishing coats, comprises (A) a system of monomers comprising: (a1) 50-90 parts of a dicyclopentenyloxyalkyl eater: where R=H or CH3; n=1 or 2; and R1=C2-C6 alkylene; (a2) 0-25 parts of at least one heavy (meth)acrylate giving a homopolymer with a Tg higher than that of a homopolymer of (a1); (a3) 0-25 parts of at least one heavy (meth)acrylate giving a homopolymer with a Tg lower than that of a homopolymer of (a1); (a4) 0-25 parts of at least one monomer containing at least two (meth)acrylic unsaturations; and (B) 5-30 parts of at least one poly(allyl glycidyl ether); and (C) an initiating system chosen from (C1) to (C4): (C1) 0.1-3 parts of at least one organic peroxide derived from a C3-C18 hydrocarbon compound and 0.1-2 parts of at least one aromatic amine; (C2) 0.

Abstract: Disclosed is a process for preparing copolymers which comprises, in the order stated: (1) adding monomers containing unsaturated carbon-to-carbon bonds, a first polymerization initiator, a second polymerization initiator, and a solvent to a reaction vessel; (2) purging the resulting solution with an inert gas; (3) sealing the reaction vessel and pressurizing it by addition of an inert gas to a pressure of from about 20 to about 600 kilopascals over ambient atmospheric pressure; (4) maintaining the temperature within the pressurized reaction vessel at a temperature of from about 50 to about 100.degree. C. for a period of from about 60 to about 300 minutes; (5) thereafter maintaining the temperature within the pressurized reaction vessel at a temperature of from about 80 to about 115.degree. C.

Abstract: Suspension polymerization of vinyl chloride in an aqueous medium is carried out in the presence of an oil-soluble polymerization initiator which is a combination of diacylperoxide compound and t-hexylperoxy diglycolate, the former having a half-life period of 10 hours at 30 to 50.degree. C. in benzene (0.05 mol/L). The resulting polymer gives a high-quality molded product which is free of odor and less liable to initial discoloration.

Abstract: There is provided a process of producing a vinyl chloride polymer wherein vinyl chloride monomer or a monomeric mixture containing vinyl chloride monomer is suspension polymerized in the presence of an oil-soluble polymerization initiator and a suspending agent in an aqueous medium in a polymerization vessel, said process comprising providing, as the oil-soluble polymerization initiator, a mixture of (A) t-butyl peroxyneoheptanoate with (B) a perester peroxide other than said t-butyl peroxyneoheptanoate, said perester peroxide being such that a 10-hour half-life period temperature of a benzene solution of said peroxide dissolved in an amount of 0.1 mole per 1 liter of benzene is 44 to 55.degree. C.; and completing the polymerization at a temperature higher than a preset temperature for the polymerization by from 10 to 20.degree. C. when or after the internal pressure of the polymerization vessel begin to drop at the terminal stage of the polymerization reaction.

Abstract: A process for the preparation of (co)polymers employing a peroxide composition comprising at least one organic peroxide wherein at least 20% of the total active oxygen content of said organic peroxide is attributable to one or more cyclic ketone peroxides represented by the following formulas I-III: ##STR1## These cyclic ketone peroxides are highly efficient as polymerization initiators.

Abstract: Copolymers of ethylene with .alpha.,.beta.-unsaturated carboxylic acids are prepared at from 50.degree. to 250.degree. C. and from 500 to 5000 bar in a stirred autoclave having a length/diameter ratio greater than 5:1 by a process in which the monomer mixtures are fed into the autoclave in at least two part-streams, the first part-stream being passed into the autoclave at the beginning of the autoclave pipe and the second part-stream being introduced at a position which is a distance away from the beginning which corresponds to 25-50% of the total length and the amount of the .alpha.,.beta.-unsaturated carboxylic acids in the first part-stream is from 20 to 90% less than the average amount in the further part-streams and a peroxide polymerization initiator having a lower decomposition temperature, or a mixture of peroxide polymerization initiators having a lower average decomposition temperature, than that of the initiators in the further part-streams is passed in with the first part-stream.

Abstract: The present invention relates a toner for developing electrostatic images, comprising: a resin composition, which contains a binder resin and low molecular weight wax, and a coloring agent, wherein the binder resin does not substantially contain insoluble tetrahydrofuran (THF) component, its chromatograph measured with soluble tetrahydrofuran (THF) component has a main peak in a region of a molecular weight of 2,000 to 30,000 and a subpeak or a shoulder in a high molecular weight region of a molecular weight of 100,000 or more, a ratio of weight average molecular weight (Mw)/number average molecular weight (Mn) thereof is 30 or more, the high molecular weight region has a crosslinking monomer unit as a component monomer unit and the binder resin contains high molecular weight polymer having a Mw of 1,200,000 or more polymerized by using both polyfunctional initiator and a mono-functional initiator. Moreover, the present invention relates to a method of manufacturing a resin composition for producing a toner.

Abstract: A process for polymerizing vinyl chloride alone or a mixture of vinyl chloride and other vinyl monomer(s) with hydroxy containing monomer(s), and the copolymer obtained thereby. The hydroxy containing monomer(s) is obtained by the partial allylation of dihydroxy or polyhydroxy alcohols. The copolymers are prepared by suspension polymerization. The presence of the hydroxyl groups significantly modifies the characteristics of the polymers. Plasticizer-take-up is increased and dry-time is reduced significantly. Furthermore, the hydroxyl groups become the sites for postpolymerization reactions due to their polarity and reactivity.

Abstract: A vinyl chloride polymer is prepared through suspension polymerization of a vinyl chloride monomer in the presence of a polymerization initiator in a reactor. The reactor is charged with up to 4/5 of the overall monomer charge to initiate polymerization. Polymerization is carried out under a certain saturated vapor pressure of P1 kgf/cm.sup.2 at a preset polymerization temperature. When the internal pressure of the reactor declines to P2 kgf/cm.sup.2, the remainder of the overall monomer charge is continuously fed to the reactor so as to maintain the internal pressure within the range of (P1-.DELTA.P) wherein .DELTA.P=P1-P2 ranges from 0.1 to 2.0 kgf/cm.sup.2. A vinyl chloride polymer having a high degree of polymerization is efficiently produced while alleviating the load of heat removal.

Abstract: Organic peroxide compositions which contain phosphomolybdic acid to retard the rate of decomposition of the peroxide compound are disclosed.

Abstract: Organic peroxide compositions which contain a .beta.-dicarbonyl compound to retard the rate of decomposition of the peroxide compound are disclosed.

Abstract: Disclosed are a styrene copolymer having a weight average molecular weight of about 200,000 to 2,000,000, having 1 to 20 branching points in the Z-average molecular weight, and having a methyl ethyl ketone/methanol mixture-insoluble matter content of not more than 5% by weight and a methanol-soluble matter content of not more than 5% by weight; processes for preparing the styrene copolymer; a polystyrene resin composition containing the styrene copolymer; and injection-molded article prepared by injection-molding the polystyrene resin composition.

Abstract: A process for preparing an acrylamide polymer is herein disclosed which comprises the step of initiating polymerization in the presence of an oxidation-reduction system polymerization initiator comprising two or more kinds of oxidizing agents and a reducing agent. According to this process, the polymerization rate can be remarkably increased without bringing about a decrease in the molecular weight of the polymer, and hence, restriction on manufacturing facilities and apparatuses can be relieved and productivity can be remarkably enhanced, which permits a decrease in manufacturing cost.

Abstract: A free radical polymerization process for producing a branched polymer from a vinyl aromatic monomer comprising polymerizing a vinyl aromatic monomer in the presence of a free radical initiator of the formula: ##STR1## wherein R is H, alkyl, or aralkyl, and R' is alkyl or aryl.

Abstract: A novel and safe ethylenically unsaturated peroxyester composition derived from an ethylenically unsaturated dicarboxylic acid is provided, as well as processes for making and using the composition. The peroxyester composition comprises about 0.04 to about 0.70 mole fraction of a first component compound having a formula I: ##STR1## about 0.32 to about 0.50 mole fraction of a second component compound having a formula II: ##STR2## about 0.04 to about 0.70 mole fraction of a third component compound having a formula III: ##STR3## wherein Q is an unsaturated ethylene divalent radical and R.sup.1 and R.sup.2 are organic substituents. Polymeric-peroxides are prepared via polymerizing the peroxyester compositions. The peroxyester compositions are also used for curing unsaturated polyester resins and for initiating polymerization of ethylenically unsaturated monomers.

Abstract: This process is a process of producing a vinyl chloride polymer by suspension polymerization of vinyl chloride or a mixture of vinyl monomers mainly made up of vinyl chloride in an aqueous medium in the presence of an oil-soluble polymerization initiator, wherein, as said oil-soluble polymerization initiator, (A) an organic peroxide such that a 10-hour half-life period temperature of a solution containing 0.1 mol of the organic peroxide per liter of benzene is 30.degree. to 50.degree. C. and the organic peroxide does not, in its structure, contain a benzene ring or an alkoxy group, and (B) 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate are used in combination. The polymerization vessel used is preferably coated with a polymer scale preventive agent.

Abstract: Vesiculated polymer beads are prepared in which a water-in-oil-in-water emulsion containing a cross-linkable polymer and a copolymerizable monomer in the oil phase is heated in the presence of an initiator to cure the polymer beads, wherein curing is commenced in a first stage in the presence of a substantially water-insoluble initiator and, when the beads are sufficiently stable, curing is completed in a second stage in the presence of an at least partially water-soluble initiator. Preferably, the completion of curing is carried out at a temperature higher than that of the first stage. The beads can be used in low odor paint formulations.

Abstract: Disclosed are a styrene copolymer having a weight average molecular weight of about 200,000 to 2,000,000, having 1 to 20 branching points in the Z-average molecular weight, and having a methyl ethyl ketone/methanol mixture-insoluble matter content of not more than 5% by weight and a methanol-soluble matter content of not more than 5% by weight; processes for preparing the styrene copolymer; a polystyrene resin composition containing the styrene copolymer; and injection-molded article prepared by injection-molding the polystyrene resin composition.

Abstract: A process for producing a monovinylidene aromatic polymer having molecular weight (Mw) greater than 275,000 which comprises polymerizing a monomer mixture comprising a monovinylidene aromatic monomer in the presence of:A) from 10 to 2000 ppm by weight of at least one free radical generating, branching polymerization initiator; andB) from 10 to 2000 ppm of one or more organic gel reduction agent selected from the group consisting of:1) mercaptans, terpenes, halocarbons and halohydrocarbons, such agent having up to 20 carbons,2) distillate recovered from the reaction devolatilization process (recycle), and3) mixtures of 1) and 2).

Abstract: A novel and safe ethylenically unsaturated peroxyester composition derived from an ethylenically unsaturated dicarboxylic acid is provided, as well as processes for making and using the composition. The peroxyester composition comprises about 0.04 to about 0.70 mole fraction of a first component compound having a formula I: ##STR1## about 0.32 to about 0.50 mole fraction of a second component compound having a formula II: ##STR2## about 0.04 to about 0.70 mole fraction of a third component compound having a formula III: ##STR3## wherein Q is an unsaturated ethylene divalent radical and R.sup.1 and R.sup.2 are organic substituents. Polymeric-peroxides are prepared via polymerizing the peroxyester compositions. The peroxyester compositions are also used for curing unsaturated polyester resins and for initiating polymerization of ethylenically unsaturated monomers.

Abstract: Process for producing polyvinyl ester having a high degree of polymerization and an intrinsic viscosity of from 15 dl g.sup.-1 to 3.2 dl g.sup.-1, and a polyvinyl ester obtained thereby. The process comprises subjecting a vinyl ester monomer to emulsion polymerization using nonionic emulsifiers nonionic-anionic emulsifiers, or anionic emulsifiers and a redox initiator at a temperature of -60.degree. to 15.degree. C.

Abstract: A process for producing a vinyl chloride polymer comprises subjecting a vinyl chloride monomer or a mixture comprising a major proportion of a vinyl chloride monomer along with at least one co-polymerizable monomer to suspension polymerization in an aqueous medium in the presence of a monomer-soluble polymerization initiator. The monomer-soluble polymerization initiator comprises, in combination, (A) a compound which is free of a benzene ring, a cyclohexyl group and an alkoxy group in the molecule and whose 10 hours half-life temperature at a concentration of 0.1 mole/liter of benzene is in the range of 30.degree. to 50.degree. C. and (B) 1-cyclohexyl-1-methylethyl peroxyneodecanoate.

Abstract: The preparation of vinyl chloride-type polymers by suspension polymerization of vinyl chloride monomers in the presence of monomer-soluble polymerization initiators, wherein the monomer-soluble polymerization initiators utilized are a combination of (A) a compound which possesses neither a benzene ring nor an alkoxyl group, and has a half-life of 10 hours at 0.1 mol/l concentration in benzene solution at a temperature of 40.degree.-50.degree. C., and (B) 1-cyclohexyl-1-methylethylperoxy pivalate.This method yields vinyl chloride-type polymers the qualities of which such as an initial colorization and thermal stability are effectively improved, without being affected by the limitations accompanied by the insufficient cooling capacity of the polymerization vessel in general. The preparative method further enables one to effectively avoid scale deposition in the polymerization vessel.

Abstract: A process for producing a vinyl chloride-based polymer, which comprises suspension polymerizing vinyl chloride monomer or a vinyl chloride-containing monomeric mixture in an aqueous medium in the presence of an oil-soluble polymerization initiator, wherein the initiator comprises (A) at least one compound having a 10-hour half-life temperature, at a concentration of 0.1 mol/l in benzene, of not lower than 35.degree. C., and (B) at least one compound having a 10-hour half-life temperature, at a concentration of 0.1 mol/l in benzene, of lower than 35.degree. C., with the amount of the initiator (B) being from 0.01 to 0.07% by weight based on the monomer or monomeric mixture and being from 10 to 30% by weight based on the total amount of the initiators (A) and (B). The process makes it possible to shorten easily the time required for raising temperature, and to produce vinyl chloride-based polymers which have a good particle size distribution and which have few fish eyes when formed into sheets or the like.

Abstract: Suspension polymers ofa) from 80 to 100% by weight of methyl methacrylate andb) from 0 to 20% by weight of further monomers capable of undergoing free radical polymerization,are obtainable by polymerization at a temperature of from 100.degree. to 140.degree. C. which is virtually constant over the major part of the polymerization time by means of an initiator system consisting of two or more peroxide initiators I having different decomposition temperatures T at which in each case half of the initiator has decomposed after 1 hour, whereinthe initiator I.sub.min having the lowest decomposition temperature has a decomposition temperature T.sub.min of from 60.degree. to 100.degree. C.,the initiator I.sub.max having the highest decomposition temperature has a decomposition temperature T.sub.max of from 100.degree. to 140.degree. C., the difference between T.sub.max and T.sub.min is greater than 10.degree. C. and I.sub.max is a perketal of the general formula (1) ##STR1## where R.sup.1 and R.sup.

Abstract: An improved process for the polymerization of styrene is provided. The process comprises feeding styrene monomer and a mixture of peroxides, which decompose at progressively higher temperatures, into a prepolymerization vessel maintained at 200.degree.-270.degree. F. About 20-40% of the styrene in this vessel is converted to polymer (depending on temperature and residence time) and then fed to an extruder where the polymer is raised in temperature by passage through a heat exchanger or through the heated throat of the extruder. During this heating, the polymerization is completed in seconds to minutes in an extruder as the peroxides decompose in sequence as the temperature rises. A final devolatilization zone is provided to remove the final traces of monomer. The molten polymer is then passed through a die and stranded or hot die face cut.

Abstract: A novel styrene type resin having excellent strength which comprises(A) a unit represented by the formula ##STR1## wherein l and n are each an integer of 1 to 20;m is an integer 0 to 5; andR.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cyclohexyl group or a phenyl groupand(B) a unit represented by the formula ##STR2## wherein R.sub.1 is a hydrogen atom or a methyl group andR.sub.2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atomsand wherein the ratio of S.sub.A (namely, an amount of structural unit (A)) to S.sub.B (namely, an amount of structural unit (B)), S.sub.A /S.sub.B, is in the range of 0.00001 to 0.006; the resin having weight average molecular weight in the range of 200,000 to 600,000; and a total amount of styrene type monomers, styrene type dimers, styrene type trimers and a solvent of not more than 0.8% by weight.

Abstract: The present invention is directed to a product and method of incrementally adding comonomers to co-polytetrafluoroethylene (PTFE) by an improved process, resulting in a PTFE product independent and/or much less dependent upon drying temperatures. The improved PTFE exhibits increased green strength at substantially constant extrusion pressures and an extrusion pressure that is substantially independent of drying temperatures of the wet PTFE.

Abstract: Process for the preparation of polymers which comprises a suspension free radical polymerization of monomers in the presence of the initiator O,O-t-amyl-O-(2-ethylhexyl)monoperoxycarbonate.

Abstract: This disclosure relates to storageable and/or transportable compositions containing a peroxydicarbonate to which an organic hydroperoxide, e.g. t-butyl hydroperoxide, has been added. The hydroperoxide serves to retard peroxydicarbonate decomposition. The compositions may be in the form of physical mixtures, aqueous dispersions or solutions in organic solvents.

Abstract: This invention relates to the polymerization of a monomer capable of forming a precipitate of polymerized particles which comprises reacting in the liquid phase said monomer in the presence of a high temperature, free radical initiator at a temperature within a critical range of between about 110.degree. and 150.degree. C. to produce a particulate polymeric product having a glass transition temperature. (Tg) in excess of the temperature at which polymerization is effected and having a residual monomer content less than 1,000 ppm.

Abstract: Polyethylene and copolymers of predominant amounts of ethylene and minor amounts of comonomers which are polymerizable with ethylene are obtainable by free radical polymerization of the monomers under from 1,500 to 5,000 bar and at from 40.degree. to 250.degree. C. by means of an initiator with virtually complete exclusion of oxygen in not less than n=3 polymerization stages, by a method in which, in the first stage, the total amount of the predominant part of the monomers are subjected to polymerization using some of the initiator required, until said polymerization comes virtually to a stop, thereafter a further part of the initiator and, if required, of the monomers are added to the mixture, which has been cooled by 20.degree.-60.degree. C., and this process is repeated in the subsequent stages until the n th stage, with the proviso that the initiators used in the (n-1) th stage have a half-life temperature of from 80.degree. to 160.degree. C.

Abstract: In a process for producing a conjugated diene copolymer, the improvement in which when copolymerizing a conjugated diene monomer with an ethylenically unsaturated nitrile monomer, at least one compound selected from a bifunctional peroxide represented by formulaR.sub.1 --OO--R.sub.2 --OO--R.sub.3 (I)wherein R.sub.1, R.sub.2 and R.sub.3 each denote a hydrocarbon group, anda bifunctional peroxycarbonate represented by formula ##STR1## wherein R.sub.4, R.sub.5 and R.sub.6 each denote a hydrocarbon group, said bifunctional peroxide and peroxycarbonate being soluble in said monomers, is used as a polymerization initiator.

Abstract: A polyvinyl chloride polymer or copolymer having excellent thermal resistance and being free from FEs and offensive smell can be obtained in a high yield through a polymerization reaction of vinyl chloride monomer alone or together with a vinyl monomer copolymerizable therewith by the use of a combination system polymerization initiator consisting of (A) .alpha.,.alpha.'-bis(neodecanoylperoxy)-diisopropylbenzene, and (B) at least one of peroxy ester, diacyl peroxide and peroxy dicarbonate, each of which has a 10-hour half-life period temperature within the range of 40.degree.-65.degree. C. in its 0.1 mol concentration solution in benzene.

Abstract: A process for producing a styrene resin by continuous bulk polymerization using a polymerization apparatus comprising a circulating line (I) for initial-stage polymerization including at least one tubular reactor having fixedly set therein a plurality of mixing elements having no moving parts and a main-polymerization line (II) following the circulating line (I) and including at least one tubular reactor having fixedly set therein a plurality of mixing elements having no moving parts; characterized in that while a polmerization solution containing a styrene monomer (A), an organic solvent (B) and an organic peroxide (C) whose half life reaches 10 hours at a temperature of 75.degree. to 130.degree. C. is polymerized in the initial stage while it is circulated through the circulating line (I), and at the same time, a minor part or a major part of the initial-stage polymerization solution is introduced continuously into the main-polymerization line (II) and polymerized.

Abstract: Excellent polymers of vinyl chloride series monomers having a good thermostability to prevent coloring and not having displeasant odor can be provided with even polymerization speed at high yield by using a specific combination system of a fast initiator and retarded initiators.

Abstract: A continuous process and system for producing a polymer comprising maleic anhydride and alpha-olefin monomeric units is disclosed. The process comprises combining monomeric reactants comprising the maleic anhydride and the alpha-olefin, in the presence of a minimal effective amount of a solvent, to produce a polymerizable reaction mixture. The solvent is present in minimal amounts, namely, at about 2 to about 9 weight percent, based upon the weight of the reaction mixture. The polymerizable reaction mixture is heated; and at least one thermally-decomposable initiator is added to the thus-heated, polymerizable reaction mixture to initiate the polymerization reaction. The presence of the initiator causes the maleic anhydride and the alpha-olefin to polymerize, thereby producing the desired polymer.

Abstract: Photopolymerization initiators of the general formula: ##STR1## wherein R.sub.1 and R.sub.1 ' independently stand for a tertiary alkyl group or a tertiary aralkyl group and R.sub.2 and R.sub.2 ' independently stand for a hydrogen atom, a tertiary alkoxy group, or a tertiary aralkyloxy group are disclosed. They are useful for effecting polymerization of radically polymerizable unsaturated compounds. Tetra peroxy esters of benzophenone are preferred.

Abstract: A process is provided for the free radical polymerization of monomers derived from substituted or unsubstituted acrylic acid/methacrylic acid and esters thereof for the production of a polymer having a narrow molecular weight distribution and an average molecular weight of less than 4000. These polymers are produced by the solution polymerizing of said monomers wherein 20-40% by weight of the monomer composition is hydroxyalkyl acrylate or methacrylate in the presence of a solvent system suitable for high solids coating applications and in the presence of an initiating amount of a tertiary alkyl hydroperoxide and/or its derivatives having at least 5 carbons wherein the initiator and monomers, alone or in combination, are added continuously at a programmed rate wherein the rate of addition corresponds approximately to the rate of decomposition of said monomer and initiator. These polymers are used for high solids coating applications.

Abstract: Copolymers which contain, as copolymerized monomer units, monoethylenically unsaturated mono- and dicarboxylic acids are prepared by a process in which(a) from 10 to 60% by weight of a monoethylenically unsaturated dicarboxylic acid of 4 to 6 carbon atoms, its salt and/or, if appropriate, its anhydride,(b) from 90 to 40% by weight of a monothylenically unsaturated monocarboxylic acid of 3 to 10 carbon atoms and/or its salt and(c) from 0 to 20% by weight of another, carboxyl-free monoethylenically unsaturated monomer which is copolymerizable with (a) and (b),the percentages being based on the sum of the monomers, are polymerized in the presence of from 0.5 to 5% by weight of a water-soluble free-radical-forming initiator in an aqueous medium at from 60.degree. to 150.degree. C.

Abstract: Process for the preparation of polymers of vinylphosphonic acid in protic diluents with the aid of catalysts which form free radicals, which comprises heating vinylphosphonic acid at temperatures of 40.degree. to 130.degree. C. in a total of 10 to 150% by weight of protic diluents for a total of 4-60 hours in the presence of 1.0 to 5.5% by weight of aliphatic peroxy-esters, diacyl peroxides and/or aliphatic azo compounds which decompose by half in one hour at temperatures below 122.degree. C.

Abstract: A specialized polymeric peroxide is copolymerized with vinyl type monomers in the presence of organic liquid, thereby obtaining a solution of a copolymer having peroxy bonds therein.This solution is admixed with vinyl type monomers which are different in composition from the ones used in the first copolymerization, and the resultant mixture is subjected to block copolymerization.The obtained block copolymer solution is admixed with an organic liquid which exert solubility to one of polymers of the vinyl type monomers which are employed in the first or second copolymerization, whereby a non aqueous system liquid dispersion is obtained.This dispersion contains a block copolymer in a high concentration and it also is splendid in uniformity of dispersion and dispersion stability.

Abstract: A process for producing acrylic polymers at a high rate which have high thermal stability, are free of defects and have a low level of unreacted monomer by polymerization of a methyl methacrylate syrup in the presence of a mixture of three peroxide initiators.

Abstract: Organic peroxydicarbonates such as bis[3-(isobutyryloxy)-2,2,4-trimethylpentyl] peroxydicarbonate are described. The peroxydicarbonates are useful as initiators for the polymerization or copolymerization of vinyl acetate and may be used in combination with the more commonly used peroxydicarbonates such as diisopropyl peroxydicarbonate.

Abstract: A plastic lens which has high hardness and excellent scratch resistance and can form a transparent and uniform reflection preventing film through vacuum deposition, is produced by mixing(a) diethylene glycol bis(allyl carbonate) with(b) at least one of organic peroxides having a decomposition temperature at selected half-life value for ten hours of not higher than 80.degree. C. and(c) at least one of specifically limited peroxycarbonates having a radical copolymerizability to the diethylene glycol bis(allyl carbonate) (a), as a polymerization initiator, and polymerizing and casting the resulting mixture in a desired lens-forming mold.

Abstract: A process for producing acrylic polymers which have high thermal stability, are free of defects and have a low level of unreacted monomer. The process includes the polymerization at a high production rate of a methyl methacrylate syrup in the presence of a mixture of two peroxide initiators. The first initiator has a 5-minute half-life at temperatures between about 75.degree. C. to 100.degree. C. and emits a maximum of 1 mole of carbon dioxide per 2 moles of free radicals. The second initiator has a one minute half-life at temperatures of between about 105.degree. C. to about 125.degree. C. and emits a maximum of 1 mole of carbon dioxide per 1 mole of free radicals.

Abstract: A process for the preparation of aqueous polymer dispersions comprising polymerizing compounds with unsaturated ethylenic bonds at a temperature of 10.degree. to 100.degree. C. in the presence of an at least partially water-soluble free-radical initiator and at least one water-soluble protein and optionally present conventional adjuvants with the starting mixture containing not more than 40% of the total monomers and the remaining monomer being added by metering during the polymerization, the initiators being at least one member of the group consisting of ketone peroxides and organic hydroperoxides in an amount of at least 30 mmol per kg of total monomer mixture and optionally present water-soluble reducing agents and the amount of protein being at least 3% by weight based on the total monomer weight and at least 30% by weight is added during the polymerization and the isoelectric point of the protein is not reached or exceeded during polymerization.

Abstract: A process for the preparation of aqueous polymer dispersions comprising polymerizing vinyl esters and up to 50% by weight of the total monomer of compounds with unsaturated ethylenic bonds at a temperature of 10.degree. to 100.degree. C. in the presence of an at least partially water-soluble free-radical initiator and at least one starch member of the group consisting of cyanalkylated starch, hydroxyalkylated starch and carboxyalkylated starch and optionally present conventional adjuvants with the starting mixture containing not more than one-third of the total monomers and the remaining monomers being added by metering during the polymerization, the initiators being at least one member of the group consisting of hydrogen peroxide and organic hydroperoxides in an amount of at least 30 mmol per kg of total monomer mixture and optionally present water-soluble reducing agent and the amount of starch being at least 1% by weight based on the total monomer weight.