Process for the manufacture of a microfibrous pulp suitable for making synthetic paper

Claim 1

A method for preparing an amorphous microfibrous pulp suitable for use in the manufacture of synthetic paper, comprising the steps of: (a) forming an aqueous emulsion of a solution in an organic solvent of a polymerization product of at least one polymer having a molecular weight of from 10 3 to 10 6 selected from the group consisting of olefinic homopolymers, olefinic copolymers, copolymers of at least one olefinic monomer with at least one further monomer copolymerizable therewith and mixtures thereof; (b) heating said emulsion above the melting point of the polymerization product; (c) spraying the hot emulsion in the form of a tubular jet into a zone of expansion in which water and the organic solvent are evaporated from the spray; (d) injecting into the cavity of the tubular jet substantially coaxially with the tubular jet a stream of inert gas to spread the jet transversely of the length of the jet in said zone of expansion.

Claim 2

A method for preparing an amorphous microfibrous pulp suitable for use in the manufacture of synthetic paper, comprising the steps of: (a) forming an aqueous emulsion of a solution in an organic solvent of a polymerization product of at least one polymer having a molecular weight of from 10 3 to 10 6 selected from the group consisting of olefinic homopolymers, olefinic copolymers, copolymers of at least one olefinic monomer with at least one further monomer copolymerizable therewith and mixtures thereof; (b) heating said emulsion above the melting point of the polymerization product; (c) spraying the hot emulsion in the form of a tubular jet into a zone of expansion in which water and the organic solvent are evaporated from the spray; (d) injecting into the cavity of the tubular jet substantially coaxially with the tubular jet a stream of inert gas to spread the jet transversely of the length of the jet in said zone of expansion.

Claim 24

A method for preparing a microfibrous pulp suitable for use in the manufacture of synthetic papers, comprising the steps of forming an aqueous emulsion of a solution in an organic solvent of a polymerization product of at least one polymer having a molecular weight from 10 3 to 10 6 selected from the group consisting of olefinic homopolymers, olefinic copolymers, copolymers of at least one olefinic monomer with at least one further monomer copolymerizable therewith and mixtures thereof, said organic solvent consisting essentially of at least one compound selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons and chlorinated hydrocarbons, said aqueous emulsion containing from 5 to 35% by weight of the polymerization product based on the organic solvent, from 0.2 to 2 kg water for each liter of said emulsion and a surfactant in a proportion from 0.2 to 5% by weight based on the weight of the polymerization product, heating said emulsion at a temperature from 150° to 250° C., said temperature being above the melting point of the polymerization product, maintaining said emulsion at a pressure from 15 to 60 atmospheres, spraying said emulsion in the form of a tubular jet into a zone of expansion while injecting into the cavity of the tubular jet substantially coaxially with the tubular jet a stream of inert gas, said stream of inert gas being fed at a pressure from 20 to 200 Kg/sq.cm. and in a proportion from 0.1 to 1 Nm 3 for each liter of emulsion and said zone of expansion being maintained at atmospheric pressure and at a temperature of 20°-25° C., thereby spreading the jet transversally of the length of the jet in said zone of expansion and evaporating said water and organic solvent from the spray.

Claim 25

A method for preparing a microfibrous pulp suitable for use in the manufacture of synthetic papers, comprising the steps of forming an aqueous emulsion of a solution in an organic solvent of a polymerization product of at least one polymer having a molecular weight from 10 3 to 10 6 selected from the group consisting of olefinic homopolymers, olefinic copolymers, copolymers of at least one olefinic monomer with at least one further monomer copolymerizable therewith and mixtures thereof, said organic solvent consisting essentially of at least one compound selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons and chlorinated hydrocarbons, said aqueous emulsion containing from 5 to 35% by weight of the polymerization product based on the organic solvent, from 0.2 to 2 kg water for each liter of said emulsion and a surfactant in a proportion from 0.2 to 5% by weight based on the weight of the polymerization product, heating said emulsion at a temperature from 150° to 250° C., said temperature being above the melting point of the polymerization product, maintaining said emulsion at a pressure from 15 to 60 atmospheres, spraying said emulsion in the form of a tubular jet into a zone of expansion while injecting into the cavity of the tubular jet substantially coaxially with the tubular jet a stream of inert gas, said stream of inert gas being fed at a pressure from 20 to 200 Kg/sq.cm. and in a proportion from 0.1 to 1 Nm 3 for each liter of emulsion and said zone of expansion being maintained at atmospheric pressure and at a temperature of 20°-25° C., thereby spreading the jet transversally of the length of the jet in said zone of expansion and evaporating said water and organic solvent from the spray.