Abstract: A process for producing a surface-modified molded product of synthetic resin, which comprises contacting a fluorine-containing gas to the surface of a molded product of synthetic resin and then contacting a polymerizable monomer to form a new polymer layer on the surface of the molded product.

Abstract: Seeded cation-exchange resin beads are particularly susceptible to oxidative degradation which results in the leaching of organic carbon fragments. The leachability of organic carbon fragments of molecular weights greater than 1000 g/mol is reduced to less than 800 ppm by effectively crosslinking the copolymers that comprise the seeded cation-exchange resin beads. Crosslinking can be achieved either during sulfonation by increasing sulfone bridge formation or before sulfonation by either alkylene bridge formation or by incorporation and subsequent activation of a crosslinkable functionality in the copolymer that forms the seed in the seeded polymer bead process.

Abstract: The present invention provides a new method for making an improved flame-retardant additive comprising a brominated syndiotactic styrenic polymer. The method includes the steps of providing a source of syndiotactic styrenic polymer; providing a source of inert reaction medium that is not capable of dissolving to any appreciable degree the syndiotactic styrenic polymer at ambient temperature and pressure; providing a source of brominating agent; providing a source of Lewis acid catalyst; mixing the syndiotactic styrenic polymer with the inert reaction medium and the Lewis acid catalyst; and reacting the syndiotactic styrenic polymer with the brominating agent to produce a brominated syndiotactic styrenic polymer.

Abstract: A partially tert-butoxylated poly(p-hydroxystyrene) is prepared by subjecting poly(p-tert-butoxystyrene) to reaction of eliminating some of the tert-butoxy groups in an organic solvent at a temperature of 30.degree.-100.degree. C. in the presence of an acid catalyst at a molar ratio of acid catalyst/t-BuO group of from 0.050 to 2.0. During the elimination reaction, a change of solubility of the resulting partially tert-butoxylated poly(p-hydroxystyrene) is determined to calculate a degree of elimination of tert-butoxy groups. The reaction is terminated when a desired degree of elimination is reached. Through a simple process, partially tert-butoxylated poly(p-hydroxystyrene) having a well controlled t-BuO content is produced in high yields.

Abstract: A method of preparing a high molecular weight water-soluble cationic copolymer by reacting in an aqueous solution at least one N-vinylamide and at least one cationic quaternary amine monomer in the presence of a free radical initiator and a salt of ethylenediamine tetraacetic acid and subjecting the formed polymer to an acid or base to form an N-vinylamide/N-vinylamine/cationic quaternary amine copolymer product.

Abstract: An anionic polymerization initiator includes the C-lithio reaction product of an organolithium compound and a tertiary-amino allyllithium or a tertiary-amino xylyllithium. When used in an anionic polymerization, a functional group from the initiator is incorporated onto the head of the growing polymer and a lithium atom is incorporated at the "living" end of the polymer chain prior to quenching. The initiator may be used to polymerize a monomer(s) including diolefin monomers, monovinyl aromatic monomers and trienes, and the living ends of the polymers are effectively maintained even at temperatures of up to 300.degree. F. and higher. Such polymers exhibit an increased efficiency in coupling termination reactions, and products prepared from such polymers exhibit improved hysteresis characteristics. Products such as tires and the like can be prepared from such polymers and from vulcanizable elastomer compositions employing the polymers.

Abstract: The invention relates to chlorinated hydroxyrubber, a method for making chlorinated hydroxyrubber via chlorinating partially hydroxylated rubber with chlorine gas, and environmentally friendly low volatile organic content coatings comprising chlorinated hydroxyrubber.

Abstract: Disclosed herein is a process for preparing a water-soluble polymer comprising subjecting an N-vinylcarboxylic acid amide alone or a mixture of the N-vinylcarboxylic acid amide and other water-soluble vinyl compound(s) copolymerizable therewith to suspension polymerization, and adding hydroxylamine followed by acidic hydrolysis. A water-soluble can be polymerized efficiently without forming gel.

Abstract: This invention relates to a process of manufacturing phosphoric acid-type chelate resins as uranyl ion adsorbents having enhanced chelation and re-utilizing ability by introducing plenty of phosphoric acid groups both on main- and side-chain of the copolymer skeleton. The resin is prepared by both the radical suspension copolymerization of vinyl monomers such as styrene, divinylbenzene, and bis-(2-chloroethyl) vinylphosphonate and the additional introduction of phosphono group onto the copolymer.

Abstract: Polyvinylamine derivatives having hydrophilic centers, processes for their preparation and the use of the compounds as a medicament, active compound carrier and foodstuff auxiliary.Polyvinylamine derivatives containing hydrophilic centers, of the formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3, X, w, x, y and z have the meanings given, and a process for their preparation, and the use of these compounds as medicaments, active compound carriers and foodstuff auxiliaries are described. Highly pure polyvinylamines having the recurring unit of the formula Ia ##STR2## the preparation of which is likewise described, are used in particular as starting substances for the preparation.

Abstract: Crosslinked, nitrogen-containing vinyl copolymers having units of the formula I ##STR1## and physiologically tolerated salts thereof, in which, in formula I, A1, A2, R, w, x, y and z have the meanings given, a process for their preparation and the use of the compounds as medicaments, active compound carriers and foodstuff auxiliaries are described.

Abstract: A method is disclosed for forming emulsion copolymers of (meth)acrolein by:(1) emulsion polymerizing from about 0.1% to about 25%, by weight, based on the total weight of the copolymer, of an acetal derivative of (meth)acrolein with from about 75% to about 99.9% by weight, based on the total weight of the copolymer, of at least one .alpha.,.beta.-ethylenically unsaturated comonomer; and(2) adjusting the pH of the copolymer to less than about 5 to hydrolyze the acetal derivative of (meth)acrolein to (meth)acrolein.The emulsion copolymers of (meth)acrolein formed by the method of the present invention demonstrate performance properties equivalent to those formed by conventional polymerization techniques without the attendant safety and health concerns while handling and transporting the monomer.

Abstract: A coating resin composition comprising (I) a vinyl polymer obtained by polymerizing (A) 1 to 100% by weight of a vinyl monomer having at least one unsaturated double bond and at least one siloxy group per molecule and (B) 99 to 0% by weight of a copolymerizable vinyl monomer other than (A) in the presence of a radical generator and (II) a curing agent having reactivity with the hydroxyl groups generated from the polymer (I), and optionally (III) a siloxy group-dissociating catalyst.

Abstract: A process for making polymers of conjugated dienes which contain hydroxyl groups in the diene blocks which comprises(a) making a precursor polymer by polymerizing at least one conjugated diene which leaves 1,2 disubstituted, 1,1 disubstituted, 1,1,2 trisubstituted or tetrasubstituted olefinic unsaturation in the polymer,(b) optionally partially hydrogenating said precursor polymer,(c) epoxidizing said precursor polymer such that epoxy groups form at said substituted sites and the amount of epoxy functionality in the polymer is from 0.1 to 5 Meq/g polymer, and(d) reacting the epoxidized polymer with an alcohol solution of hydrochloric acid.A diene polymer containing 0.1 to 10 Meq/g polymer of hydroxyl group and comprised of alcohol units of the formula ##STR1## where R.sub.1 and R.sub.2 are hydrogen or alkyl radicals and X and X' are either --OH or --Cl and at least one of them is --OH.

Abstract: A process for making polymers of conjugated dienes which contain hydroxyl groups in the diene blocks which comprises(a) making a precursor polymer by polymerizing at least one conjugated diene which leaves 1,2 disubstituted, 1,1 disubstituted, 1,1,2 trisubstituted or tetrasubstituted olefinic unsaturation in the polymer,(b) optionally partially hydrogenating said precursor polymer,(c) epoxidizing said precursor polymer such that epoxy groups form at said substituted sites and the amount of epoxy functionality in the polymer is from 0.1 to 5 Meq/g polymer, and(d) reacting the epoxidized polymer with an alcohol solution of hydrochloric acid.A diene polymer containing 0.1 to 10 Meq/g polymer of hydroxyl group and comprised of alcohol units of the formula ##STR1## where R.sub.1 and R.sub.2 are hydrogen or alkyl radicals and X and X' are either --OH or --Cl and at least one of them is --OH.

Abstract: A propylene (co) polymer terminated with a reactive group and a process for the preparation of the same.A graft copolymer having a specific side chain and a process for the preparation of the same.The propylene (co) polymer is usable as a radial- or ion-polymerizable propylene macromonomer or as an intermediate for the preparation of a block polymer. Examples of the application thereof include compatibizing agent for polymers, light- or laser-curable plastic, viscosity index and surface modifier.The graft copolymer is useful as a surface modifier or compatibilizing agent for polypropylene or a dispersant for fillers.

Abstract: A curable resin composition comprising (a) an acrylic polymer having a plurality of alicyclic epoxide functions, and (b) an amount effective to initiate the curing reaction of the acrylic polymer (a) upon heating of a heat-latent cation polymerization initiator. The composition finds its uses in coating compositions, sealants, potting and casting compositions.

Abstract: A surface-modified fibrillated fiber composition is disclosed herein which comprises polyacrylonitrile homopolymer or copolymer and a surface of pendant N-haloamide groups. Also disclosed is a process for the production of said composition.

Abstract: A process for making polymers of conjugated dienes which contain hydroxyl groups in the diene blocks which comprises(a) making a precursor polymer by polymerizing at least one conjugated diene which leaves 1,2 disubstituted, 1,1 disubstituted, 1,1,2 trisubstituted or tetrasubstituted olefinic unsaturation in the polymer,(b) optionally partially hydrogenating said precursor polymer,(c) epoxidizing said precursor polymer such that epoxy groups form at said substituted sites and the amount of epoxy functionality in the polymer is from 0.1 to 5 Meq/g polymer, and(d) reacting the epoxidized polymer with an alcohol solution of hydrochloric acid.A diene polymer containing 0.1 to 10 Meq/g polymer of hydroxyl group and comprised of alcohol units of the formula ##STR1## where R.sub.1 and R.sub.2 are hydrogen or alkyl radicals and X and X' are either --OH or --Cl and at least one of them is --OH.

Abstract: Disclosed is a process for producing dental polymeric shaped articles resistant to the adhesion of plaque which comprises the steps of shaping and curing a dental composition containing a monomer having at least one (meth)acryloyloxy group, and bringing the cured product into contact with a halogen or a halogen compound. Also disclosed is a dental composition comprising a monomer having at least one (meth)acryloyloxy group and a polymerization initiator, which is characterized by having added thereto at least one of a halogen and a halogen compound. When cured, this dental composition produces dental polymeric shaped articles resistant to the adhesion of plaque.

Abstract: This invention provides cationic acrylamide polymers which are highly effective as paper strength agents, drainage agents and suspension flocculants, and which do not show much temporal deterioration; it also provides a method of manufacturing said polymers wherein the manufacturing equipment is compact and can be installed on site, and the cationicity of the polymers can be modified in a short time.This invention comprises a method of manufacturing cationic acrylamide polymers by reaction, with a hypohalogenite, of a (meth)acrylamide homopolymer, a copolymer of (meth)acrylamide and acrylonitrile, a copolymer of (meth)acrylamide and, N,N-dimethylacrylamide, in a high temperature range of 50.degree.-110.degree. C. for a short time; the polymers manufactured by said process; and paper strength agents, drainage agents and flocculants having these polymers as their principal constituent.

Abstract: N-vinylformamide is polymerized with or without other water-soluble monoethylenically unsaturated monomers and with or without water-insoluble monoethylenically unsaturated monomers in not less than 30% strength by weight aqueous monomer solutions in the presence of a polymerization initiator at not more than 150.degree. C. in a kneader by a method in which the polymerization is carried out to such an extent that the initially formed water-containing polymer gel disintegrates into fine particles and the finely divided polymer obtainable in this manner is hydrolyzed, preferably in the kneader, so that not less than 0.1 mol % of the N-vinylformamide units present in the polymer are converted into vinylamine units. The polymers obtainable in this manner dissolve readily in water. The aqueous solutions are used, for example, in papermaking and tertiary oil production.

Abstract: A process for halogenating star-branched butyl rubber is provided wherein water and a wetting agent or wetting agent precursor are added to a solution comprising the star-branched butyl rubber, solid particles of branching agent and an organic solvent prior to the neutralization step to increase the rate of neutralization of the hydrogen halide by-product of the halogenation reaction.

Abstract: The present invention provides a process for the production of polymers with an optical position in diagram where refraction index n.sub.D is plotted against optical dispension v.sub.D expedient for an optical use by metathetic counterion exchange, wherein, in a polymer of the general formula: ##STR1## R.sub.1 and R.sub.2, which can be the same or different, are divalent organic radicals, R.sub.3 and R.sub.4, which can be the same or different, are monovalent organic radicals, n is a whole number greater than 2 and y is 0 or 1. R.sub.1, R.sub.2, R.sub.3, R.sub.4, y and n are so chosen that together they form a polymeric basic structure which promotes glass formation and prevents crystallisation, and X.sup.- is a halogen atom. The halogen ion is replaced by an equivalent of a mono- or polyvalent organic or inorganic counterion different from the halogen ion and suitable for the adjustment of the desired solid body properties.

Abstract: Poisoning or deactivation of conventional homogeneous catalysts to be used in hydrogenation of the backbone unsaturation in liquid monofunctional and difunctional-terminated conjugated diene polymers, is prevented by reacting a blocking agent compound with the functional end groups present in these polymers. More specifically, subsequent to formation of a selected starting material monofunctional or difunctional-terminated conjugated diene polymer, a suitable blocking agent is reacted with the functional end groups of the polymer enabling relatively inexpensive titanium, iron, cobalt, or nickel-based homogeneous catalysts to be used in hydrogenating the backbone unsaturation of the polymer to a high degree. Subsequent to hydrogenation, the polymer is subjected to conventional hydrolysis using a mineral acid or base to remove the blocking groups and return the hydrogenated conjugated diene polymer to its original functionality.

Abstract: Crosslinked copolymer particles comprising hydrophilic crosslinked copolymer particles with a hydrophobic functional group being bonded thereto via an oxygen atom derived from a hydroxyl group of said hydrophilic crosslinked copolymer, which are obtained by reacting hydrophilic crosslinked copolymer particles with a reagent for introducing a hydrophobic functional group in an organic solvent capable of swelling said hydrophilic crosslinked copolymer particles, said hydrophilic crosslinked copolymer particles being prepared by suspension polymerization of glycerol monomethacrylate and a crosslinking polyvinyl compound in the presence of an organic solvent, such as a monohydric alcohol having from 5 to 14 carbon atoms. The polymer particles are useful as a carrier for gel-filtration of hydrophilic biopolymers such as proteins and nucleic acids.

Abstract: PVP-HI-I.sub.2 complexes having a partition coefficient above 300 were prepared by oxidizing a PVP-HI intermediate in air and light at room temperature. These complex products were light in color, water soluble and stable.

Abstract: A heterofunctional macromer represented by the formula: ##STR1## in which R.sub.1 is H or C.sub.1 -C.sub.4 alkyl; R.sub.2 is a (poly) lactone or (poly) ether chain; X.sub.1 is --COO--, --COOCH.sub.2 CH.sub.2 OCO--, --CONHCOO--, --COOCH.sub.2 CH.sub.2 NH--COO-- ##STR2## X.sub.2 is --O--, --COO-- or --OCO--NH--R.sub.3 --NHCOO--group; R.sub.3 is C.sub.1 -C.sub.6 alkylene, aromatic or alicyclic group; A is --CH.sub.2 --, --C(CH.sub.3).sub.2 -- or ##STR3## and reactive polymers derived from said macromer.

Abstract: This invention provides cationic acrylamide polymers which are highly effective as paper strength agents, drainage agents and suspension flocculants, and which do not show much temporal deterioration; it also provides a method of manufacturing said polymers wherein the manufacturing equipment is compact and can be installed on site, and the cationicity of the polymers can be modified in a short time.This invention comprises a method of manufacturing cationic acrylamide polymers by reaction, with a hypohalogenite, of a (meth)acrylamide homopolymer, a copolymer of (meth)acrylamide and acrylonitrile, a copolymer of (meth)acrylamide and N,N-dimethylacrylamide, in a high temperature range of 50.degree.-110.degree. C. for a short time; the polymers manufactured by said process; and paper strength agents, drainage agents and flocculants having these polymers as their principal constituent.

Abstract: This invention relates to a process for reducing the formation of carbonyl halide in bromine chloride and to an improved process for the bromination of compounds with BrCl in the presence of a carbonyl halide poisonable catalyst.

Abstract: A unique polymer was synthesized via copolymerization of vinylpyridine and acetoxystyrene under radical-initiated conditions followed by acidic or basic hydrolysis of the acetoxy group to afford the corresponding hydroxy group. The built-in acid-base dual functionality (phenolic and pyridyl units) in this polymer backbone gives rise to its unique solubility properties over a wide pH range in both aqueous and non-aqueous media. Due to its amphoteric nature, this polymer finds application as an anti-stat, viscosity modifier, and/or ion-exchange resin.

Abstract: The method of crosslinking polyvinylpyrrolidone (PVP) which comprises: copolymerizing vinyl pyrrolidone (VP) and an aminoalkene, a hydroxyalkene, or an aminoalkyl acrylamide or methacrylamide, to provide a crosslinkable, functional PVP copolymer as a starting material; then (a) condensing predetermined amounts of the starting material and a haloacetal under basic conditions to form a stable, crosslinkable PVP copolymer intermediate containing an acetal group as a functional appendant on the PVP polymer backbone; (b) acidifying the basic solution to hydrolyze the acetal group to an aldehyde group, and (c) crosslinking the aldehyde-functional PVP copolymer with the amine group of the amine-functional PVP copolymer, present on the polymer as free amine after step (a), or as added amine-functional copolymer to the reaction mixture, under basic conditions.

Abstract: Alkali-resistant core-shell polymers having an acid-insoluble core and an acid-soluble shell are prepared by sequential emulsion polymerization of a monomer mixture having acid-ionizable functionality such that the resulting polymer has an acid-insoluble core and an acid-soluble shell. Films from these alkali-resistant, core-shell polymers are resistant to high pH environments where alkali-resistance is required. The alkali-resistant, core-shell polymers are useful in applications such as inks, clear overprint varnishes, coatings, metal adhesion, fiber treatment, paper treatment, cathodic deposition coatings, stain blocking, coagulants and flocculants.

Abstract: A room-temperature curable resin composition comprising (a) an acrylic polymer having a plurality of alicyclic epoxide functions, and (b) an amount effective to initiate the curing reaction at room-temperature of the acrylic polymer (a) of a proton-donating cation polymerization initiator. The composition finds its uses in coating compositions, sealants, potting and casting compositions.

Abstract: Chlorinated ethylene-.alpha.-olefin copolymer rubber of the present invention is characterized in that the content of chlorine bonded to primary carbon atom is 0.6 % by weight or more and the content of chlorine bonded to tertiary carbon atom is 1.6 % by weight or less. This chlorinated ethylene-.alpha.-olefin copolymer rubber has a high vulcanization speed and excels in heat resistance. Additionally, this thermoplastic elastomer composition consisting of this vulcanizate and crystalline polyolefin resin particularly excels in moldability and processibility.

Abstract: The invention relates to bidimensional organic membranes or diaphragms and to their preparation processes.These diaphragms have at least one monomolecular layer of organic molecules A, such as porphyrins, phthalocyanines and porphyrazines. In a layer, each molecule A is directly or indirectly bonded to n (n.gtoreq.3) identical molecules A by n bonds arranged symmetrically with respect to the center of the molecule A.Therefore there diaphragms have microscopic physical properties identical in at least two directions of the plane of the diaphragm. They can be used as conductive diaphragms.

Abstract: The monomer cis-5,6-bis(trimethylsiloxy)-1,3-cyclohexadiene can be polymerized with certain nickel II catalysts, such as bis[(allyl)trifluoroacetatonickel(II)], bis[(allyl)pentafluorophenoxynickel(II)], and bis[(allyl)iodonickel(II)]. The resulting polymer is a precursor to poly(para-phenylene). Other substituted cyclohexadienes may also be polymerized by these catalysts to form useful polymers.

Abstract: A copolymer of a C.sub.4 to C.sub.7 isoolefin and a para-alkylstyrene is provided as well as the corresponding halogenated, functionalized and grafted derivatives thereof. Processes for producing these copolymers are also provided.

Abstract: Polymers of olefin monomers and a substantially uniform concentration of carboxyl, hydroxyl, thio, amino, carbonyl and imino functional group-containing monomers. Polymers of olefin monomers and carboxyl, hydroxyl, thio, amino, carbonyl and imino functional group-containing monomers substantially devoid of halogen. Method for preparing polymers by reacting carboxyl, hydroxyl, thio, amino, carbonyl and imino functional group-containing monomers with non-halogenated organometallic compounds to form masked, functional group-containing monomers and polymerizing polymer chain monomers with the masked, functional group-containing monomers to produce a polymer chain. Method for forming masked, functional group-containing monomers by reacting carboxyl, hydroxyl, thio, amino, carbonyl and imino functional group-containing monomers with non-halogenated organometallic compounds. Masked, carboxyl, hydroxyl, thio, amino, carbonyl and imino functional group-containing monomers.

Abstract: Ethylene/.alpha.-olefin polymers grafted with perfluoro-substituted, ethylenically-unsaturated epoxides and then reacted with perfluoro-substituted nucleophiles, provide enhanced wear resistance to lubricating oils.

Abstract: A bead composition is disclosed herein which comprises a core of a polyacrylonitrile homopolymer or copolymer and a surface of pendant N-haloamide groups. Also disclosed is a process for the production of said composition.

Abstract: A process for the preparation of polymers of isobutene having tertiary chloride groups by reaction of appropriate polymers which have been prepared by cationic polymerization of isobutene with hydrogen chloride.

Abstract: A metal treatment solution comprising an effective amount of a soluble or dispersible compound which is a derivative of a polyphenol. A composition for treatment and after treatment of metal with polyphenol compounds is provided. The present invention includes novel derivatives of polyphenol compounds which are useful in surface treatment solutions or dispersions. A method for using these solutions or dispersions is also provided. The molecular weight of the polyphenols used to form the derivatives of the present invention are in the range of from about 360 to 30,000 or greater. The resulting derivatives of the present invention typically have molecular weight of up to about 2,000,000 with molecular weights within the range of about 700 to about 70,000 being preferred.

Abstract: A radioluminescent light source comprises a solid mixture of a phosphorescent substance and a tritiated polymer. The solid mixture forms a solid mass having length, width, and thickness dimensions, and is capable of self-support. In one aspect of the invention, the phosphorescent substance comprises solid phosphor particles supported or surrounded within a solid matrix by a tritium containing polymer. The tritium containing polymer comprises a polymer backbone which is essentially void of tritium.

Abstract: Novel styrene derivatives are disclosed of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are the same or different and each represents a saturated aliphatic hydrocarbon group or an aromatic hydrocarbon group, and R.sub.3 is --OH, Cl, or a group of the formula --OR.sub.4 or ##STR2## wherein R.sub.4 represents a saturated aliphatic hydrocarbon group or an aromatic hydrocarbon group. The functionalized styrene monomers I as well as polymers and copolymers incorporating such monomer units are useful as initiators, or precursors thereof, for the polymerization of isobutylene under cationic conditions to give graft copolymers containing both styrenic and isobutylenic units. These copolymers have commercial applications such as rubbers, coatings, and lubricants.

Abstract: A composition is disclosed herein which comprises a core of a polyacrylonitrile homopolymer or copolymer and a surface of N-haloamides. Also disclosed is a process for the production of said composition.

Abstract: A no-post-cure method of curing polyacrylates having dual cure sites is accomplished with a two-part curing system or a combined one-part curing system. The two-part curing system consists of one or more metallic acid salts and an ammonium and/or phosphonium quaternary salt. The one-part curing system consists of an ammonium or phosphonium quaternary acid salt. The polyacrylate rubber must have both a halogen and a carboxyl cure site. The method consists of blending the curative with the polyacrylate rubber and heating the resultant composition until the composition cures. Because the mixed composition is shelf stable, it is not necessary to immediately heat the composition to cure it. The method may optionally include the step of storing the mixed composition until it is desired to cure it.

Abstract: This invention relates to a process for hydrolysing polymeric amides with a hydrolysing agent at elevated temperatures under the influence of ultrasound in a homogeneous reaction medium. The reaction is particularly suited to the production of polyacrylic acid from polyacrylamide.

Abstract: .[.Disclosed herein is a vinylamine copolymer having the structural units represented by the following formulas (I), (II), (III), (IV) and (V): ##STR1## wherein X.sup..crclbar. represents an anion or hydroxyl ion, R represents a hydrogen atom or a methyl group, M.sup..sym. represents a hydrogen ion or a monovalent cation, in which the molar fraction of the structural unit (I) is 5 to 85% by mole, the molar fraction of the structural unit (II) is 2 to 85% by mole, the molar fraction of the structural unit (III) is 5 to 80% by mole, the molar fraction of the structural unit (IV) is 0 to 40% by mole, all of said molar fractions being based on the vinylamine copolymer and the molar fraction of the structural unit (V) is 0 to 8% by mole which is based on the total content of the structural units (III), (IV) and (V), a flocculating agent and a paper strength increasing agent using the vinylamine copolymer, and a process for producing the vinylamine copolymer..]..Iadd.

Abstract: Disclosed herein is a vinylamine copolymer having the structural units represented by the following formulas (I), (II), (III).[.,.]. .Iadd.and .Iaddend.(IV) .[.and (VI).].: ##STR1## wherein x.crclbar. represents an anion or hydroxyl ion R represents a hydrogen atom or a methyl group, M.sym. represents a hydrogen ion or a monovalent cation, in which the molar fraction of the structural unit (I) is 5 to 85% by mole, the molar fraction of the structural unit (II) is 2 to 85% by mole, the molar fraction of the structural unit (III) is 5 to 80% by mole,.[.the molar fraction of the structural unit (IV) is 0 to 40% by mole,.]. all of said molar fractions being based on the vinylamine copolymer, and the molar fraction of the structural unit .[.(V).]. (.Iadd.IV) is 0 to 8% by mole which is based on the total content of the structural units (III).[.,.]. .Iadd.and .Iaddend.(IV), .[.and (V),.].