Abstract: This invention relates to improved silyl linkers, methods for their preparation and their use in the solid phase synthesis of aromatic carbocycles, especially electron deficient aromatic carbocycles.

Abstract: A rubber composition exhibiting excellent low rolling resistance, high wet skid properties, and superior wear resistance, and suitably used as a vulcanized rubber for tire tread. The rubber composition comprises a styrene-butadiene copolymer previously extended using an extender oil, in an amount from 30 to 100 wt % of the total rubber components, and an extender oil in an amount from 6 to 50 parts by weight for 100 parts by weight of the total rubber components, of which 20 to 50 parts by weight of the extender oil for 100 parts by weight of styrene-butadiene copolymer is used to previously extend the styrene-butadiene copolymer. The styrene-butadiene copolymer has a styrene content from 5 to 45 wt %, 20 to 80% of a microstructure 1,2-bond of butadiene portion, a glass transition temperature from -55.degree. C. to -20.degree. C., and 40 wt % or more of a single styrene bond and 10 wt % or less of long styrene chain which contains 8 or more styrene molecules, among the total styrene bonds.

Abstract: A monomer such as butadiene monomer and/or styrene monomer is polymerized using an organic lithium initiator, and the active terminal of a (co)polymer thus obtained is modified with a specific modifier having reactivity with a silica surface, e.g., .gamma.-glycidoxypropyl trimethoxysilane and .gamma.-methacryloxypropyl trimethoxysilane, and then the terminally-modified (co)polymer is mixed with a silica in an organic solvent. The rubber obtained can be used in a tire tread and the like.

Abstract: A silica-blended rubber composition comprising 100 parts by weight of sulfur-vulcanizable rubber blended with 10 to 100 parts by weight of silica, 3 to 20% by weight of a silane coupling agent based on the silica and 1 to 20% by weight of sodium borate based on the silica. An alkoxy group-containing silane coupling agent is preferred as the silane coupling agent, and sodium tetraborate is preferred as the sodium borate.

Abstract: A process for producing a flame-retardant, silane-crosslinked polyolefin, characterized by melt-mixing a flame-retardant polyolefin consisting of an .alpha.-olefin polymer, a flame-retardant, a water-absorbing agent and a silanol-condensing catalyst with a substantially water-free carrier polymer comprising an organic unsaturated silane and a free-radical generator at a higher temperature than the crystalline melting point of the base polymer of the flame-retardant polyolefin to subject them to reaction and then contacting the reaction mixture with water to subject the reaction mixture to crosslinking.

Abstract: A method of (co)polymerizing vinyl and/or diene monomers comprising contacting the monomers with a (co)polymeriztion composition under conditions effective to (co)polymerize the monomers, wherein the (co)polymerization composition comprises: (a) an organic peroxide component, and (b) a heteropoly acid, in an amount effective to lower the onset temperature of decomposition of the organic peroxide component with the proviso that if the heteropoly acid is phosphomolybdic acid the organic peroxide is not a peroxydicarbonate.

Abstract: Disclosed is a curable resin which comprises at least one polymer selected from polymers each independently having a polymer chain represented by the following formula (I): ##STR1## wherein A to F are monomer units constituting a main chain of the polymer and are arranged in any order, and a to f are, respectively, wt % of A to F, based on the total weight of A to F; wherein each A is independently selected from cyclic olefin monomer units having no reactive group, each B is independently selected cyclic conjugated diene monomer units having no reactive group, each C to F is independently selected from comonomer units having no reactive group, and copolymerizable with A and B, wherein Q.sub.1 to Q.sub.6 are reactive groups, and wherein the average total number (J) of Q.sub.1 to Q.sub.6 of the at least one polymer satisfies: 1.ltoreq.(J).ltoreq.4, the polymer having an ME of from 1,000 to 5,000,000. A resin composition containing the curable resin is also disclosed.

Abstract: The present invention provides a rubber composition and a pneumatic tire using the rubber composition. The rubber composition comprises a diene base rubber comprising at least 15% by weight of a polybutadiene rubber, silica in an amount of 10 to 80 parts by weight per 100 parts by weight of the diene base rubber and, in an amount of 1 to 20% by weight of the amount of silica, a specific silane coupling agent, i.e., a bis (alkoxysilylalkyl) polysulfide having a polysulfide chain in which the distribution of sulfur is specified. After curing, the cured rubber composition includes closed cells. Therefore, the rubber composition has a good processability at the time of manufacturing of a tire and a pneumatic tire using the same has excellent snow/ice grip performance and abrasion resistance.

Abstract: A curable composition comprising the components (A), (B), (C) and (D), viz.(A) an isobutylene polymer which contains in a molecule, at least one alkenyl group capable of hydrosilylation reaction;(B) a curing agent which contains at least two hydrosilyl groups in a molecule;(C) a hydrosilylation catalyst; and(D) an organic compound which contains in a molecule, at least one alkenyl or alkynyl group capable of hydrosilylation reaction.This composition is excellent in workability because of its low viscosity, and has such advantages that the cured product thereof has large strength and further that the weight loss by heating is small. Since a large amount of an inorganic filler can be blended with this composition, it is possible to obtain a composition having high thixotropy and little sagging.

Abstract: A functionalized polymer prepared by a process comprising the steps of preparing a solution of a cyclic amine compound, an organolithium compound, and from 3 to about 300 equivalents, based upon one equivalent of lithium, of a monomer selected from the group including diene monomers, vinyl aromatic monomers, and mixtures thereof, where the cyclic amine compound is defined by the formula where R.sub.2 is selected from the group consisting of an alkylene, substituted alkylene, oxy- or N-alkylamino-alkylene group having from about 3 to about 16 methylene groups, N is a nitrogen atom, and H is a hydrogen atom, thereby forming a polymerization initiator having the formula where Li is a lithium atom, SOL is a divalent hydrocarbon group having from 3 to about 300 polymerized monomeric units, y is from 0.5 to about 3, and A is a cyclic amine radical derived from the cyclic amine, charging the solution containing (A)Li(SOL)y with from about 0.

Abstract: A method is disclosed for processing a rubber composition comprising thermomechanically mixing the rubber composition while maintaining a rubber temperature in a range of from 160.degree. C. to 190.degree. C. for a period of time ranging from 4 to 8 minutes, wherein said rubber composition is characterized by(i) 100 parts by weight of at least one sulfur vulcanizable elastomer containing olefinic unsaturation;(ii) 10 to 250 phr of a filler selected from the group consisting of silica, carbon black and mixtures thereof; and(iii) 0.5 to 50 phr of an ester of the formula: ##STR1## wherein R.sup.1 is selected from the group consisting of alkyls having from 16 to 18 carbon atoms and alkenyls and alkadienyls having from 16 to 18 carbon atoms; and R.sup.2 is selected from the group consisting of alkyls having from 12 to 22 carbon atoms.

Abstract: The present invention relates to silicone poly(meth)acrylates, to a process for their preparation from alkoxysiloxanes and hydroxy-functional poly(meth)acrylates and to their use as an additive in coatings, especially as an antigraffiti additive.

Abstract: Oligomeric organosilicon compounds are disclosed of the formula I ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 independently of one another denote H, (C.sub.1 -C.sub.4)alkyl, (C.sub.1 -C.sub.4) alkoxy, (C.sub.1 -C.sub.4) haloalkoxy, (C.sub.1 -C.sub.4)haloalkyl, phenyl, aryl or aralkyl andZ denotes an alkylidene radical having 0-6 carbon atoms, x can be a statistical average of 1-6 andn=1-150 and . . . means that z can be bonded either to the one or the other C atom, and the particular free valency is occupied by a hydrogen.and their use in rubber mixtures and for the production of shaped articles, in particular pneumatic tires.

Abstract: A functionalized polymer includes a polymer chain carrying at least one functional group selected from alkyl, dialkyl and cycloalkyl amine radicals having the general formula ##STR1## and cyclic amine radicals having the general formula ##STR2## where R.sub.1 is an alkyl, cycloalkyl or aralkyl having from 1 to about 12 carbon atoms, and R.sub.2 is an alkylene, substituted alkylene, oxy- or N-alkylamino-alkylene group having from about 3 to about 16 methylene groups. The invention also provides products based upon such polymers.

Abstract: The invention disclosed involves the use of heteropoly acids as promoters to decompose organic peroxides.

Abstract: Hair care compositions which provide improved styling and hair conditioning properties are disclosed. The compositions comprise from about 0.1% to about 10.0% of a specifically-defined silicone copolymer and from about 0.5% to about 99.5% of a carrier suitable for application to hair. These compositions are characterized by the fact that, when dried, the polymer phase separates into a discontinuous phase which includes a silicone macromer and a continuous phase which includes the copolymer backbone.

Abstract: Novel polymeric compounds having pendent fluoroaliphatic groups, pendent organic-solubilizing groups, and pendent groups capable of reacting with an epoxy silane; which have been reacted with an epoxy silane have been discovered. These compounds are easy to apply, abrasion and impact resistant, and provide durable, low surface energy, streak reducing surfaces on coating dies, edge guides, and other coating and fluid contacting surfaces.

Abstract: (Meth)acrylic polymers having alkenyl or curable silyl groups at the chain ends high functionality ratios are prepared by a process which comprises (i) preparing a (meth)acrylic polymer having halogen atoms at the chain ends, using an organohalogenated compound or a halosulfonyl compound as an initiator and a metal complex catalyst wherein the central metal atom is selected from the group consisting of the elements of Groups 8, 9, 10 and 11 of the periodic table; and (ii) transforming the halogen atom into an alkenyl group- or a curable silyl group-containing substituent. The obtained (meth)acrylic polymers form homogeneous curing materials.

Abstract: An acyclic alkane soluble anionic polymerization initiator includes a mixture of from about 90 to about 10 parts by weight of a lithio amine having the general formula A.sub.1 Li and from about 10 to about 90 parts by weight of at least one other lithio amine having the general formula A.sub.2 Li. A.sub.1 and A.sub.2 are selected from the dialkyl, alkyl, cycloalkyl and dicycloalkyl amine radicals and cyclic amine radicals. There is also provided a method of forming a mixture of anionic polymerization initiators, a functionalized polymer and a method of forming a functionalized polymer.

Abstract: Polymeric polyamines obtainable by reacting linear, alternating carbon monoxide/1-alkene copolymers with ammonia or amines of the formula (I)R--NH.sub.2 (I)where R is --NH.sub.2, --OH, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.20 -aryl, C.sub.7 -C.sub.20 -arylalkyl, C.sub.7 -C.sub.20 -alkylaryl or an organosilicon radical having 3 to 30 carbon atoms,or with a reagent which releases ammonia or the amine (I), and subsequent hydrogenation.

Abstract: Mixtures are disclosed of bis(silylorganyl)polysulfanes and silylorganylthiocyanates, which are produced by reacting polysulfanes with cyanides. The inorganic thiocyanate formed is subsequently allowed to react with a haloalkylalkoxysilane to form the silylorganylthiocyanate. These substances are used in plastic and rubber mixtures reinforced with silica and optionally carbon black.

Abstract: A sulfur-vulcanizable rubber composition which in vulcanized state is of roved hysteresis, comprising silica as reinforcing filler and a polymer which is coupled and/or starred by means of an agent having the general formula:(Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.3--n --R.sup.3 nin whichY represents the radical ##STR1## R.sup.1 represents an alkyl, cycloalkyl, or aryl radical having 1 to 10 carbon atoms,R.sup.2 represents an alkyl, aryl, cycloalkyl, alkaryl or aralkyl radical having from 1 to 12 carbon atoms,R.sup.3 represents an alkyl, aryl or alkaryl radical having 1 to 12 carbon atoms,R.sup.4 represents a hydrocarbon radical having 1 to 6 carbon atoms and may comprise one or more oxygen atoms in the hydrocarbon chain,n is a whole number selected from among the values 0 and 1,m is a whole number selected from among the values 1 and 2,p and q are whole numbers selected from among the values 0, 1, 2, 3 and 4, it being understood that the sum of p+q must represent a whole number between 2 and 5 inclusive.

Abstract: A process for removing a protecting group from a polymer. Protected functional groups of a polymer may be deprotected by treating the polymer in the presence of an acid catalyst, including organic acids, mineral acids, heterogeneous acid systems, Lewis acids, and fluoride ion sources.

Abstract: Protected functional initiators have been demonstrated to polymerize dienes and alkenyl substituted aromatics. The resultant living anions were linked with a coupling agent, such as divinylbenzene or tin tetrachloride, to afford a protected functionalized star polymer. Subsequent deprotection afforded a star polymer, with functional groups on the end of each arm of the star. The star polymer could be hydrogenated before or after removal of the protecting groups. The newly liberated functional groups can participate in further polymerization chemistry.

Abstract: Protected, functionalized heterotelechelic polymers, hydrogenated and/or deprotected analogues thereof, and processes to prepare these polymers. Monomers are polymerized using a protected functionalized initiator to form a living polymer, and the living polymer is reacted with an electrophile to form heterotelechelic polymers.

Abstract: The present invention provides waterborne crosslinkable polymer compositions encompassing (A) functional latex polymers containing at least one pendant ethylenically unsaturated functional group, (B) a silicon hydride compound containing at least two reactive hydrogen atoms, and (C) a catalyst suitable to attain a crosslinked film.

Abstract: The present invention is directed toward anionic polymerization employing lithio amines mixed with an organic alkali metal compound and optionally, a chelating reagent. The lithio amines have the general formula (A)Li(SOL)y, where SOL is a solubilizing component, A is an alkyl, dialkyl, cycloalkyl or dicycloalkyl amine radical or a cyclic amine, and y is 0 or is from about 0.5 to about 3. The invention is also directed toward polymers and other products made using the initiator, and methods therefor. Further, the invention contemplates a polymer, a polymer composition and products therefrom, which include a functional group from the reaction product of an amine and an organolithium compound. The resulting polymers may be terminated with a terminating, coupling or linking agent, which may provide the polymer with a multifunctionality.

Abstract: A method of increasing the adhesion of a rubber (as hereinbefore defined) or rubber-based material which includes treating at least part of the surface of the rubber or rubber-based material with a halogenating agent simultaneously with a static and/or high freguency alternating physical field.

Abstract: A process for producing a polyacetal copolymer, which is extremely heat-stable and is extremely reduced in the quantity of unstable terminals even in a high polymerization yield in which trioxane as the principal monomer, comprises copolymerization of trioxane as the principal monomer with a cyclic ether or cyclic formal having at least one carbon-to-carbon bond as the comonomer by using a specific heteropoly-acid or acid salt thereof as a polymerization catalyst until the content of the remaining monomers is lowered to at most 10% by weight based on all the monomers fed, adding 0.01 to 10% by weight, based on the resulting crude polymer, of a solution containing a catalyst deactivator, or contacting a basic gas as the deactivator to deactivate the catalyst, and subjecting the crude polymer as such to heat melting treatment without washing thereof.

Abstract: Ionomeric polymers are provided which are dispersible in aqueous solvents yet which cross-link with ethylenically unsaturated monomers to form matrices having relatively low solubility in such solvents. The polymers can be incorporated into photocurable composition for use, for example, in photocurable printing elements.

Abstract: The invention relates to a polymer for release films of surfaces containing pressure-sensitive adhesives. The polymer includes a reactive polyolefin and a reactive release substance, which are chemically bonded together as a result of being compounded in a molten state. The invention also relates to a release film for surfaces containing pressure-sensitive adhesives.

Abstract: Polyalkenylaromatic-polyethylene copolymers are prepared using protected functional organolithium initiators. Polymerization of an alkenylsubstituted aromatic monomer followed by ethylene, results in a protected functional block polystyrene-co-polyethylenyllithium. Termination with a functionalizing agent followed by deprotection produces polymeric products with high functionalization at the initiating chain-end and at least partial functionalization at the terminal chain-end.

Abstract: There is provided a method of introducing functionality into a copolymer of an isoolefin and an alkylstyrene at the alkylbenzyl carbon atom comprising the steps of: forming a solution of said copolymer in a hydrocarbon solvent; adding to said polymer solution an alkali metal Cs, K, Na alkoxide and an alkyl lithium compound to form a superbase with the polymer solution; and adding an electrophile to said base polymer solution also provided are the metalated copolymers and the functionalized derivative therefrom.

Abstract: Trans 1,4-copolymers of butadiene and isoprene are provided as blends with other elastomers, including partial replacement of natural cis 1,4-polyisoprene in elastomer compositions. Pneumatic rubber tires with components composed of such elastomer blends, including tire treads, are also included.

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

Abstract: There is provided a method of introducing functionality into a copolymer of an isoolefin and an alkylstyrene at the alkylbenzyl carbon atom comprising the steps of: forming a solution of said copolymer in a hydrocarbon solvent; adding to said polymer solution an alkali metal Cs, K, Na alkoxide and an alkyl lithium compound to form a superbase with the polymer solution; and adding an electrophile to said base polymer solution also provided are the metalated copolymers and the functionalized derivative therefrom.

Abstract: A process for the preparation of hydrocarbon solutions of monofunctional ether initiators of the following general structure:M--Q.sub.n --Z--OA(R.sup.1 R.sup.2 R.sup.3)wherein M is defined as an alkali metal, selected from the group consisting of lithium, sodium and potassium, Q is an aromatic substituted saturated hydrocarbyl group produced by the incorporation of one or more alkenyl substituted aromatic hydrocarbons containing 8-25 carbon atoms into the M--Z linkage; Z is a branched or straight chain hydrocarbon group which contains 3-25 carbon atoms, optionally containing aryl or substituted aryl groups; A is an element selected from carbon and silicon; R.sup.1, R.sup.2, and R.sup.

Abstract: Cross-linked controlled density polyamines which are water-insoluble and swell at pH values up to about 8 are shown. These polyamines are useful in site-specific drug delivery systems.

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

Abstract: High clarity optical and safety glass laminate interlayer films and optical laminates are described. The films and their laminates comprise very low density polyethylene and/or its copolymers, preferably polymerized with metallocene catalysts, and modified with additives, such as coupling agents, clarifying or nucleation agents, UV-light absorbers, pigment or color concentrate, and IR-light blockers.

Abstract: The surface-modified fillers according to the invention are manufactured by treating oxidic or siliceous fillers with a silane of the formulaR.sup.1 R.sup.2 R.sup.3 Si--X.sup.1 --(--S.sub.x --Y--).sub.m --(--S.sub.x --X.sup.2 --SiR.sup.1 R.sup.2 R.sup.3).sub.nand are used for the manufacture of rubber vulcanizates, particularly tyres, with reduced dynamic damping and favourable abrasion behaviour.

Abstract: An ocular lens obtained by reacting a hydroxyl group-containing polymer shaped to have an ocular lens shape, with a silicon-containing compound of the formula (I):O.dbd.C.dbd.N--R.sup.1 --Si.sub.n O.sub.n-1 (CH.sub.3).sub.2n+1 (I)wherein R.sup.1 is a C.sub.1-6 linear or branched alkylene group, and n is an integer of from 1 to 15.

Abstract: A polypropylene resin composition having a high moldability and capable of forming therefrom shaped articles having excellent surface hardness, thermal deformation resistance and low temperature impact resistance includes (A) 35-74 wt % of a crystalline ethylene-propylene block copolymer with an ethylene content of 0.5-15 wt %, an isotactic pentad fractional propylene of 96% or more and a MFR of 40-80 g/10 min. (230.degree. C., 2160 g); (B) 21-40 wt % of an ethylene-.alpha.-olefin copolymer produced by using a single site catalyst and having an .alpha.-olefin content of 70 mol % or more, a ratio (Mw/Mn) of 2.5 or less, and a ratio (MI.sub.10 /MI.sub.2.16) of 6 to 15; and (C) 5-25 wt % of a talc particle component having an average particle size of 3-7 .mu.m.

Abstract: A curable composition comprising an aged mixture of tetramethoxysilane with water added in excess of the theoretical amount sufficient for the hydrolysis and condensation of 100% of the silane and a reactive organic compound having at least two functional groups capable of condensing with the product of hydrolysis and condensation of the silane in the above mixture.

Abstract: A reactive monomer for preparing ultraviolet absorbing polymers has formula (I) wherein R.sup.1 is a halogen or C.sub.1 -C.sub.6 straight or branched chain alkoxy group; and R.sup.2 is a --(CH.sub.2).sub.3 O--, --(CH.sub.2).sub.2 O--, --CH(CH.sub.3)CH.sub.2 O--, --CH.sub.2 CH(CH.sub.3)O--, --(CH.sub.2).sub.3 OCH.sub.2 --, --(CH.sub.2).sub.2 OCH.sub.2 --, --CH(CH.sub.3)CH.sub.2 OCH.sub.2 --, or --CH.sub.2 CH(CH.sub.3)OCH.sub.2 -- group. The compound can be used to produce ultraviolet absorbing polymers, such as those used for ocular devices including contact and intraocular lenses.

Abstract: An acyclic alkane soluble anionic polymerization initiator includes a mixture of from about 90 to about 10 parts by weight of a lithio amine having the general formula A.sub.1 Li and from about 10 to about 90 parts by weight of at least one other lithio amine having the general formula A.sub.2 Li. A.sub.1 and A.sub.2 are selected from the dialkyl, alkyl, cycloalkyl and dicycloalkyl amine radicals and cyclic amine radicals. There is also provided a method of forming a mixture of anionic polymerization initiators, a functionalized polymer and a method of forming a functionalized polymer.

Abstract: In a polymerization process of at least one of monomers selected from the group consisting of conjugated diene compounds such as butadiene and vinylaromatic compounds such as styrene, an organolithium compound such as butyllithium is added to the polymerization system first in the presence of the monomer, and thereafter a secondary amine compound such as saturated cyclic imine is added thereto to produce a soluble initiator by bringing the both compound into contact with each other. Polymerization is carried out with the soluble initiator formed. The obtained high molecular weight polymer is modified with a coupling agent such as tin tetrachloride. The polymer obtained has a high molecular weight, a narrow molecular weight distribution, and controlled molecular weight, and exhibits remarkable coupling property, low hysteresis loss. The process provides a polymer having a consistent characteristic, regardless of production scale and procedures of adding materials.

Abstract: There is provided a melt extrudable, moisture curable thermoplastic polymer which is produced from a silane modified elastomeric polymer and which has improved hysteresis, reduced stress decay and improved creep properties. The polymer may be processed into a nonwoven web, film, fiber or foam which may be laminated to other materials such as spunbond polyolefin layers and may be used in medical, personal care, feminine hygiene and other applications.

Abstract: A hydrophilic soft gas permeable contact lens having substantially improved clinical performance by the provision of a sufficient higher proportion of hydroxy acrylic units to silicon units in the lens surface layer, as compared to that existing in the lens core, by the surface treatment of the lens, such as by reacting of the lens surface with polyols and base or acid or by radiation treatment of the base lens to graft, deposit or coat thereon hydroxy acrylic units.

Abstract: According to the present invention, there are provided a process for producing a vinyl alcohol polymer comprising reaction of a vinyl ester polymer (A) having an epoxy group with a compound (B) having a thiol or thioester group and hydrolysis thereof, said hydrolysis being conducted during or after said reaction; and a process for producing a vinyl alcohol polymer comprising reaction of a vinyl ester polymer (C) having a thiol or thioester group with a compound (D) having an epoxy group and hydrolysis thereof, said hydrolysis being conducted during or after said reaction. According to the present invention, it is possible to efficiently introduce into PVA various functional groups having excellent reactivity, crosslinkability, ionic interactivity, water-solubility, interfacial physical properties, low-temperature flexibility, etc., under relatively mild reaction conditions.