Abstract: Method for the preparation of a partially hydrolyzed polyvinyl acetate by polymerizing vinyl acetate in ethanolic solution at a vinyl acetate/ethanol weight ratio of lower than 0.7, cooling the solution until it separates into upper and lower phases, separating the lower phase containing polyvinyl acetate, and hydrolyzing the polyvinyl acetate. The resultant partially hydrolyzed polyvinyl acetate is suitable for use in polymerization of vinyl chloride in aqueous suspension.

Abstract: Articles including ophthalmic devices prepared by a process comprising the steps of thermoforming a polymer comprising units derived from an ethylenically-unsaturated monomer bearing at least one trihaloacetoxy-substituent group, by heating the polymer in a mold or in sheet-form at a temperature in the range of 100.degree. to 400.degree. C. for about 5 seconds to 15 minutes, and then cooling said polymer, to provide a shaped article, solvolyzing the resulting shaped article to provide a hydroxy-substituted polymeric shaped article, and optionally hydrating said hydroxy-substituted polymeric shaped article to provide a shaped hydrogel article. When the polymer is derived from vinyl trihaloacetate it has a syndiotactic stereochemical configuration.

Abstract: A process for the preparation of cationized polyvinyl alcohol (PVA) by reaction of alkylidene epoxides with PVA in alkaline medium in the presence of water, in which the reaction mixture contains 11 to 30 weight % of water, based on its total amount, and 1 to 4 weight % of an alkali metal or alkaline earth metal hydroxide or alkaline earth metal oxide, based on the quantity of PVA. As the cationizing agent there are used alkylidene epoxides or their mixtures having the general formula ##STR1## wherein n - 1, 2 or 3, R.sub.1, R.sub.2 and R.sub.3 represent the same or different alkyl residues having 1 to 18 carbon atoms or R.sub.1 represents the benzyl or --C.sub.2 H.sub.4 OH, and X.sup.- denotes chloride, bromide, sulfate or acetate.

Abstract: This invention relates to a process for the production of poly(vinyl alcohol) having a weight average molecular weight of at least about 0.4.times.10.sup.6 by polymerizing vinyl acetate at a temperature of from about 0.degree. C. to about 40.degree. C. in the presence of an azo free radical polymerization initiator essentially in the absence of ultraviolet radiation to form an essentially linear poly(vinyl acetate) having a weight average molecular weight of at least about 1.0.times.10.sup.6 and thereafter hydrolyzing the poly(vinyl acetate) to form the desired poly(vinyl alcohol).

Abstract: Disclosed herein is a new process for producing polyvinyl ester having a high degree of polymerization having an intrinsic viscosity not less than 1.5 dl/g, preferably not less than 2.2 dl/g, and most preferably higher than 3.2 dl/g, said process comprising subjecting vinyl ester monomer to low-temperature emulsion polymerization under specific conditions.Disclosed also herein is a new process for producing polyvinyl alcohol having a high degree of polymerization having an intrinsic viscosity not less than 1.5 dl/g, preferably not less than 2.2 dl/g, and most preferably higher than 3.2 dl/g, said process comprising saponifying in the usual way the polyvinyl ester obtained by low-temperature emulsion polymerization under specific conditions.

Abstract: The present invention provides a process for producing easily on an industrial scale a polyvinyl ester having a high degree of polymerization and PVA having a high degree of polymerization derived by saponification form such a polyvinyl ester. The process of this invention makes it possible to produce the desired product especially even when the polymerization is carried out until a high conversion to polymer is attained, as well as even when the polymerization is suspended while the conversion to polymer is still low.

Abstract: A resin-like product having a degree of hydrolysis of 50 to 70 mole percent is obtained by selective alcoholysis of a vinyl ester copolymer, if desired in the form of a mixture with a vinyl ester homopolymer. The starting material employed is preferably a vinyl acetate/crotonic acid copolymer. The resin is suitable for use as a hot-melt adhesive which forms coherent films capable of being activated by water or water vapor.

Abstract: Hydroxyl-containing polymers are prepared by catalytic hydrogenation of acyloxy-containing polymers by a process in which a strong base is added to the acyloxy-containing polymers before or during the hydrogenation.

Abstract: A method is provided for reducing the solvent content and increasing the sticking temperature of polyvinyl alcohol, which is prepared from the alcoholysis of polyvinyl acetate, charged to a dryer. The polyvinyl alcohol from the alcoholysis reaction, without prior vacuum drying at an elevated temperature, is slurried in a liquid medium comprising methanol, methyl acetate, water and, optionally, a nonsolvent for polyvinyl alcohol. The slurry is heated to at least 60.degree. C. for at least 5 minutes. The polyvinyl alcohol burnt particle count is reduced in the subsequent drying step and a product is afforded which has a reduced ash content and increased cold water solubility and low temperature solubility.

Abstract: A process as disclosed for producing vinylic alcohol copolymers by reacting vinyl ester or carbon monoxide copolymers with organometallic compounds in a homogeneous reaction medium.

Abstract: An improved poly(vinyl acetate) which on hydrolysis and reacetylation has an intrinsic viscosity of at least about 5 dL/g and an improved poly(vinyl alcohol) which on acetylation yields poly(vinyl acetate) having an intrinsic viscosity of at least about 5 dL/g. Such poly(vinyl acetate) can be prepared by photo-initiated free radical bulk polymerization of vinyl acetate with controlled low initiator concentration, polymerization temperature and reaction time. Such poly(vinyl alcohol) can be prepared by conventional alcoholysis of the poly(vinyl acetate).

Abstract: A composition for lining the walls of reactors and other connected apparatus in contact with reactant mixtures and reaction products during the polymerization of vinyl compounds, which reduces or prevents polymer deposits or incrustations on the said walls, constituted by the product of the prolonged reaction at 75.degree. C. between a polyvinyl alcohol of medium degree of hydrolysis prepared by the controlled alkaline alcoholysis of an ester of a wide molecular weight distribution polyvinyl alcohol and a polycarboxylic oxyacid, in a weight ratio of beween 35:10 and 40:10, which is applicable by known means, preferably by spraying.

Abstract: A surface treatment for ethylene/vinyl acetate copolymer film resulting in an elastomeric, heat sealable film which retains its transparency after release from 200 percent elongation. The treatment comprises irradiation and controlled surface hydrolysis and, optionally, subsequent attachment of mineral particulates to the surface of the film with or without the use of coupling agents.

Abstract: A process is provided for obtaining particles of thermoplastic resin which comprises agitating said resin in the molten state in an aqueous dispersion system comprising a resin dispersing amount of an alkali metal soap and an oversized particle formation-suppressing amount of an alkaline earth metal soap and cooling the resulting dispersion to obtain said resin as finely divided particles of which no more than about 5 weight percent of the total exceeds an average diameter of about 420 microns.

Abstract: Polyvinyl alcohol is manufactured by the alcoholysis of polyvinyl esters, in particular polyvinyl acetate, in the presence of a basic catalyst and in the presence of an alkanol as the solvent. The degree of polymerization of the polyvinyl ester used as the starting material is normally within the range from 400 to 10,000. The catalyst used is preferably an alkali metal hydroxide or an alkali metal alcoholate. The alcoholysis is effected by first preparing a solution of the polyvinyl ester, which is then trans-esterified at an elevated temperature. The resulting polyvinyl alcohol exhibits a high degree of purity. It is suitable for use as a base material for the production, by thermoplastic methods, of shaped articles, chiefly by compression molding, injection molding and extrusion.

Abstract: A process for the preparation of a substantially dust-free PVA powder comprising contacting the PVA with about 0.5 percent to 4.0 percent polyglycol, preferably about 0.5 percent to 2.0 percent polyglycol, based on the weight of the PVA, and the product therefrom.

Abstract: A saponified ethylene-vinyl acetate copolymer composition, improved in behavior in the molten state, which comprises: a saponified ethylene-vinyl acetate copolymer, with an ethylene content of 20-80 mole percent and a saponification degree of at least 85 percent, and 0.00005 to 0.005 percent by weight, based on said copolymer, of manganese, copper or mixtures thereof; said composition, when extracted with pure water, giving an acidic extract, is disclosed, along with a method of making the same.

Abstract: In the hydrolysis of methyl acetate to acetic acid, the improvement comprising a flasher or stripper to separate methyl acetate and water from the hydrolyzer product stream and the recycle of these directly to the hydrolyzer.

Abstract: Improved process for the preparation of partially alcoholyzed polyvinyl acetate having good compositional uniformity comprises rapid premixing of the polyvinyl acetate polymer and base catalyst solutions in a static mixer and carrying out the alcoholysis reaction in an intermeshing, self-wiping, twin-rotor mixer or mixing extruder. The process yields polyvinyl alcohol product having a maximum hot water insoluble fraction of about 1.1% by weight obtained by the proper adjustment of the feed temperature, the shear rate in the premixer and the catalyst concentration in the catalyst feed solution.

Abstract: Foamable copolymers and copolymer mixtures comprising 35% to 98% by weight ethylene, 1% to 30% by weight vinyl alcohol, 1% to 30% by weight acrylic acid esters of secondary or tertiary alcohols, and 0 to 5% by weight vinyl ester are disclosed. All percentages are based upon the total weight of the copolymer or mixture. Methods of foaming such materials, foamed materials made therefrom, and methods of preparation thereof are also disclosed.

Abstract: A water-soluble cationic copolymer and methods for producing the same is disclosed which comprises comonomer units respectively represented by the formulae: ##STR1## wherein R.sup.1 is H or lower alkyl; B is ##STR2## R.sup.2, R.sup.3 and R.sup.4 are each independently lower alkyl or lower alkyl which contain a substituent; X is an anion capable of forming a salt with the ammonium nitrogen; and A is a group which links the nitrogen atom in B to the amide nitrogen atom.These copolymers are used in preparing paper strength additives.

Abstract: A spherical powder of a hydrolyzed ethylene-vinyl acetate copolymer or its carboxyl modified product, is prepared by a method which comprises mixing 100 parts by weight of (1) a hydrolyzed product of an ethylene-vinyl acetate copolymer having 5 to 50% by weight of vinyl acetate group content or (2) a carboxyl modified product of the aforementioned hydrolyzed product obtained by reacting said hydrolyzed product with an unsaturated carboxylic acid or cyclic acid anhydride, with 10 to 100 parts by weight of an organic solvent capable of dissolving said hydrolyzed product or its carboxyl modified product, the solvent being not freely miscible with water and having a boiling point of not lower than 80.degree. C., 300 to 1000 parts by weight of water and 0.

Abstract: Powders of thermoplastic resins such as polyethylene homopolymer and ethylene-vinyl acetate copolymer are obtained by agitating molten resin in admixture with water and in the presence of a dispersing amount of an alkali metal salt of an organophosphate ester. The particle size distribution of the dispersed resin can, if desired, be regulated by the addition of base thereto.

Abstract: According to the invention there are provided a thermoplastic resin for use in a coating resin, and a process for preparing such resin, said thermoplastic resin being a hydrolyzed product of a vinyl chloride copolymer obtained by polymerizing 50 to 80% by weight of a vinyl chloride monomer, 20 to 40% by weight of a vinyl ester monomer and 0 to 15% by weight of a comonomer polymerizable with the vinyl chloride monomer, said vinyl chloride copolymer having an average polymerization degree of 200 to 800 and said hydrolyzed product having an absorption ratio of OH/CH in the infrared absorption spectrum of from 0.5 to 0.9.

Abstract: Particles of ethylene-vinyl ester interpolymer containing at least about 30% by weight of copolymerized vinyl ester which are produced in aqueous dispersion media when recovered from such media exhibit a tendency to coalesce into unmanageable agglomerates which is prevented herein by adding an anti-coalescing amount of a lower saturated aliphatic monohydroxyl alcohol such as ethanol or isopropanol to the dispersion media and recovering the interpolymer particles therein in the alcohol-wet condition.

Abstract: This invention relates to novel partially saponified polyvinyl acetates with a degree of hydrolysis of 30 to 65 mole % which might be considered as vinyl alcohol-vinyl acetate block copolymers. The invention relates further to the application of said novel block copolymers as a pore-forming additive used together with at least one known protective colloid in the homo- and copolymerization of vinyl compounds, primarily of vinyl chloride in a pure aqueous medium.

Abstract: In the manufacture of a vinyl chloride copolymer solution by dissolving in an organic solvent a vinyl chloride copolymer consisting of 50 to 90 wt % of vinyl chloride and 10 to 50 wt % of vinyl ester and having a mean polymerization degree of 100 to 800 and hydrolyzing the solution in the presence of alcohol, the viscosity of the hydrolyzed solution of the vinyl chloride copolymer is adjusted to 500 to 1000 CPS and the alcohol and the organic solvent are distilled at a temperature below 60.degree. C. under a reduced pressure of 100 to 200 Torr and, when the alcohol content in the hydrolyzed solution becomes less than 0.5 wt %, the atmospheric pressure is restored.

Abstract: A foamable copolymer comprising 40 to 98 percent by weight units of ethylene, 1 to 30 weight percent units of vinyl alcohol, 1 to 30 weight percent units of acrylic acid ester of a secondary or tertiary alcohol, and up to 2 percent by weight of vinyl acetate units is described together with a process for the manufacture thereof. The same is useful in the formation of a foamed mass which is relatively highly cross-linked. The copolymer can be foamed to form a foam by heating the same at 250.degree. to 350.degree. C. for 5 to 60 minutes in the absence of oxygen.

Abstract: Process for the production of partially-hydrolyzed ethylene-vinyl ester interpolymers by the controlled alcoholysis of the base resins, in which discoloration of the hydrolyzed products is suppressed by the rapid addition of the alcoholysis catalyst to the reaction medium. In reactions carried out over periods of from 0.5 to 200 minutes, the catalyst is thus added to the medium within periods of from 0.1 to 20 minutes at substantially uniform rates varying by no more than .+-.25% over the period of addition. Substantially colorless hydrolyzed resins of particular application for packaging films are thereby produced.

Abstract: A crosslinked copolymer of an olefin and vinyl alcohol is produced by crosslinking a copolymer of the olefin and a vinyl ester to produce a crosslinked precursor, hydrolyzing the crosslinked precursor copolymer to produce a crosslinked copolymer of an olefin and vinyl alcohol.

Abstract: The difficulty of successfully and rapidly filtering finely divided ethylene-vinyl ester interpolymer particles containing at least about 30% by weight of copolymerized vinyl ester from aqueous dispersion media is overcome by the addition of an anti-coalescing amount of a lower saturated aliphatic monohydroxyl alcohol such as ethanol or isopropanol to the aqueous dispersion media accompanied by, or followed with, agitation prior to recovering the interpolymer particles therefrom. Maintaining the filtered ethylene-vinyl ester interpolymer particles in the alcohol-wet condition resists the tendency of the particles to coalesce into unmanageable agglomerates, formation of which otherwise tends to limit or even preclude the use of the interpolymer with respect to some applications. Solid phase alcoholysis of the alcohol-wet ethylene-vinyl ester interpolymer filter cake is also disclosed.

Abstract: Powders of thermoplastic resins such as polyethylene homopolymer and ethylene-vinyl acetate copolymer are obtained by agitating molten resin in admixture with water in the presence of a dispersing system comprising a dispersing amount of a surface active agent selected from the group consisting of sulfates, sulfonates, sarcosinates, taurates, isethionates, fatty amido phosphates, fatty amide derivatives, amido amines, higher alkyl amines, substituted imidazolines, substituted betaines, ethoxylated alkylol amides, ethoxylated phenols and ethoxylated fatty ethers in combination with a dispersion promoting amount of strong base. Optionally, the dispersing system can also contain a water-soluble substantially neutral salt to further promote dispersion formation.

Abstract: Recovery of partially hydrolyzed copolymers of vinyl acetate and unsaturated carboxylic or sulfonic acid from aqueous solution dissolving them by adding an acid to the solution at a temperature of at least 40.degree. C. and then separating the deposited copolymers. This process can be advantageously applied to waste water dissolving the above hydrolyzed copolymers from desizing and washing of textile. About 70 to about 90% of the hydrolyzed copolymers dissolved in the solution can be recovered, and the recovered copolymers can be reused as a sizing agent for fibers.

Abstract: Finely divided saponified ethylene-vinyl acetate copolymer particles are prepared by forming an aqueous dispersion of the copolymer without effecting any appreciable saponification of the dispersed copolymer and thereafter saponifying the dispersed copolymer to the extent desired.

Abstract: Process for the production of partially-alcoholyzed ethylene-vinyl ester interpolymers by controlled alcoholysis of the base resins in which discoloration is suppressed by gas-sparging the base polymer in solution prior to alcoholysis.

Abstract: A size for textile fiber which comprises a modified polyvinyl alcohol type resin obtainable by the alkali saponification of a copolymer comprising a vinyl ester and an ethylenically unsaturated dicarboxylic acid substantially free from the monoester, diester and anhydride as essential and predominant copolymeric units. The size has excellent adhesive and cohesive strengths with respect to textile fibers as well as superior desizing properties and workability.