National Distillers and Chemical Corporation

Dorothee M McClain

Betty L Vest

John M Hoyt

The presence of a water-soluble substantially neutral salt significantly improves the recovery filtration of dispersions of ethylene-vinyl acetate polymers of 35 to 85 percent vinyl acetate content.

Process for recovering ethylene-vinyl acetate copolymers from an aqueous

Ethylene-acrylic acid copolymers or salts thereof are prepared by first preparing an ethylene-alkyl acrylate copolymer, saponifying such ethylene-alkyl acrylate copolymer in the molten state, in the absence of solvent or water other than by-product alkanol, with selected metal hydroxides to form alkanol and a salt, or an ionomer, of ethylene-acrylic acid copolymer, and optionally acidifying such salt to form ethylene-acrylic acid copolymer.

Preparation of ethylene-acrylic acid copolymer or salt thereof

A process is disclosed for obtaining olefin-polar comonomer resin in fibrous form. According to the invention, an olefin-polar comonomer resin such as an ethylene-vinyl acetate copolymer is vigorously agitated in molten form in water in the presence of a resin dispersion-forming amount of an alkali metal soap such as sodium stearate and a fiber-forming amount of base such as sodium hydroxide at a temperature below the degradation temperature of the resin to provide a dispersion of said resin in which a substantial number of the individual resin particles are in the form of a fiber possessing an average length of from about 50 to about 2500 microns and an average length to diameter ratio of at least about 3:1. Following cooling of the dispersion to below the solidification point of the resin, the resin fiber may be recovered employing known and conventional means, e.g., filtration, centrifugation, etc.

Dispersion process for preparing thermoplastic resin fiber

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 a substantially water insoluble ionomer polymer.

Finely divided ionomer coated thermoplastic resin

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.

Process for suppressing the formation of oversized particles of

Process for the preparation of finely divided thermoplastic resin

Powders of self-dispersing ionomer polymer of controlled particle size distribution are obtained by agitating molten resin in admixture with water and in the presence of a particle size distribution regulating amount of acid or base.

Process for regulating the particle size distribution of self-dispersing

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 a substantially water soluble salt of an interpolymer of (i) at least one ethylenically unsaturated ester derived from an alpha, beta-ethylenically unsaturated carboxylic acid and a lower alkanol and (ii) at least one alpha, beta-ethylenically unsaturated carboxylic acid as dispersing agent.

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.

Process of preparing finely divided thermoplastic resins

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.

Alcohol-wet particles of ethylene-vinyl ester interpolymer

The tendency of ethylene-vinyl ester interpolymer particles containing at least about 25% by weight of copolymerized vinyl ester to coalesce in the aqueous dispersion media in which they are prepared and consequently form unmanageable agglomerates which render impossible or greatly impede the practical filtration of the interpolymer particles, a tendency which becomes more pronounced with increasing vinyl ester content, is substantially diminished by adding an anti-coalescing amount of at least one water soluble alkanolamine processing aid to the aqueous dispersion media, or wash water used in recovery of the polymer particles prior to the recovery of the interpolymer particles therefrom. While in the alkanolamine-wet condition, the ethylene-vinyl ester interpolymer filter cake continues to resist coalescence and as such constitutes an excellent starting material for the preparation of hydrolyzed ethylene-vinyl ester resins by solid phase alcoholysis.

Alkanolamine processing aid for ethylene-vinyl ester interpolymer

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.

Rapid filtration of ethylene-vinyl ester interpolymer particles from

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.

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.

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Cincinnati, OH, United States of America

Dorothee M McClain