US3993718A — Method of manufacturing an artificial paper

Claim 1

Independent Claim 256 words

A process for the manufacture of artificial paper requiring neither calendering nor biorientation, which comprises homogenizing in a conventional rotary mixer a composition containing: 30 to 94.8% by weight of at least one rigid polyolefin (A) selected from the group consisting of homopolymers and copolymers of ethylene, propylene, and butylene, and also mixtures thereof, and having a melt index of at most 1 dg./min. 0.1 to 35% by weight of at least one polymer (B) which is incompatible with the rigid polyolefin (A and which when extruded by itself produces a brittle film and which has a melt index lower than 10 dg./min., the polymer (B) being selected from the group consisting of homopolymers and copolymers containing a preponderant amount of styrene; 0.1 to 35% by weight of a macromolecular material (C) producing compatibility between (A and (B) which is a mixture prepared in advance by melting and mixing together at least one homopolymer of ethylene, propylene or butylene, and at least one homopolymer of isobutylene, butadiene or isoprene, or butyl rubber, said material (C) having a melt index of at most 2 dg./min.; 5 to 45% by weight of an inorganic filler (D) having a particle size lower than 50 microns; 0 to 10% by weight of adjuvants (E) selected from the group consisting of antioxidizing agents, thermal stabilizers, optical bleaching agents, pigments, coloring materials, antistatic agents, and lubricants; the mixture thus homogenized being subjected to extrusion to obtain an artificial paper, and the artificial paper thus obtained, if desired, being subjected to surface treatment.

Claim 2

Dependent Claim 256 words

A process for the manufacture of artificial paper requiring neither calendering nor biorientation, which comprises homogenizing in a conventional rotary mixer a composition containing: 30 to 94.8% by weight of at least one rigid polyolefin (A) selected from the group consisting of homopolymers and copolymers of ethylene, propylene, and butylene, and also mixtures thereof, and having a melt index of at most 1 dg./min. 0.1 to 35% by weight of at least one polymer (B) which is incompatible with the rigid polyolefin (A and which when extruded by itself produces a brittle film and which has a melt index lower than 10 dg./min., the polymer (B) being selected from the group consisting of homopolymers and copolymers containing a preponderant amount of styrene; 0.1 to 35% by weight of a macromolecular material (C) producing compatibility between (A and (B) which is a mixture prepared in advance by melting and mixing together at least one homopolymer of ethylene, propylene or butylene, and at least one homopolymer of isobutylene, butadiene or isoprene, or butyl rubber, said material (C) having a melt index of at most 2 dg./min.; 5 to 45% by weight of an inorganic filler (D) having a particle size lower than 50 microns; 0 to 10% by weight of adjuvants (E) selected from the group consisting of antioxidizing agents, thermal stabilizers, optical bleaching agents, pigments, coloring materials, antistatic agents, and lubricants; the mixture thus homogenized being subjected to extrusion to obtain an artificial paper, and the artificial paper thus obtained, if desired, being subjected to surface treatment.

Claim 3

Dependent Claim 24 words

A process according to claim 1, in which the polyolefin (A) is selected from the group consisting of high density polyethylene and isotactic polypropylene.

Claim 4

Dependent Claim 22 words

A process according to claim 1, in which the polyolefin (A is a physical mixture of high density polyethylene and isotactic polypropylene.

Claim 5

Dependent Claim 18 words

A process according to claim 1, in which the polyolefin (A) is a copolymer of ethylene and propylene.

Claim 6

Dependent Claim 47 words

A process according to claim 1, in which the polymer (B) is a mixture containing a major amount of a homopolymer of styrene and a minor amount of a homopolymer obtained by polymerization of an olefinic compound selected from the group consisting of isobutylene, butadiene and isoprene.

Claim 7

Dependent Claim 42 words

A process according to claim 1, in which the polymer (B) is a copolymer obtained by copolymerization of a major amount of styrene and a minor amount of a polymerizable olefinic monomer selected from the group consisting of isobutylene, butadiene and isoprene.

Claim 8

Dependent Claim 22 words

A process according to claim 1, in which the polymer (B) is plasticized with 0.1 to 30% by weight of a plasticizer.

Claim 9

Dependent Claim 96 words

A process according to claim 1, in which the macromolecular material (C) is selected from the group consisting of a 50/50 mixture of high or low density polyethylene and polyisobutylene, a 90/10 mixture of high or low density polyethylene and polyisobutylene, a 75/25 mixture of high or low density polyethylene and polybutadiene, a 50/50 mixture of isotactic polypropylene and polybutadiene, a 70/30 mixture of high density polyethylene and butyl rubber, a 50/50 mixture of isotactic polypropylene and polyisobutylene, a 90/10 mixture of low density polyethylene and polyisoprene and a 60/40 mixture of isotactic propylene and polyisoprene.

Claim 10

Dependent Claim 18 words

A process according to claim 1, in which the composition used contains 40 to 80% of polyolefin (A).

Claim 11

Dependent Claim 20 words

A process according to claim 1, in which the composition used contains 5 to 30% by weight of polymer (B).

Claim 12

Dependent Claim 19 words

A process according to claim 1, in which the composition used contains 6 to 25% of macromolecular material (C).

Claim 13

Dependent Claim 41 words

A process according to claim 1, in which macromolecular material (C) contains 50 to 90% by weight of homopolymer of ethylene, propylene or butylene, and 10 to 50% by weight of homopolymer of isobutylene, butadiene or isoprene or of butyl rubber.

Claim 14

Dependent Claim 36 words

A process according to claim 1, in which the inorganic filler (D) is selected from the group consisting of talc, titanium dioxide, kaolin, zeolites, silica, zinc oxide, natural or precipitated calcium carbonate, magnesium carbonate and barytine.

Claim 15

Dependent Claim 27 words

A process according to claim 1, in which the antioxidizing agent used as adjuvant (E) is selected from the group consisting of 4,4'-thio-bis(6-t-butyl-metacresol, 4,4'-methylene-bis(2,6-di-t-butylphenol) and butylated hydroxytoluenes.

Claim 16

Dependent Claim 26 words

A process according to claim 1, in which the optical bleaching agent used as adjuvant (E) is selected from the class of sulfonated derivatives of stilbene.

Claim 17

Dependent Claim 28 words

A process according to claim 1, in which the lubricant used as adjuvant (E) is selected from the group consisting of magnesium stearate, calcium stearate, and paraffin oil.

Claim 18

Dependent Claim 23 words

A process according to claim 1, in which the mixing of the composition in the rotary mixer is carried out at ambient temperature.

Claim 19

Dependent Claim 21 words

A process according to claim 1, in which the extrusion is carried out at a temperature between 100° and 290° C.

Claim 20

Dependent Claim 21 words

A process according to claim 1, in which the artificial paper is further subjected to a surface treatment by corona effect.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-11-23	1980-05-24	1980-11-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-11-23	1984-05-24	1984-11-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-11-23	1988-05-24	1988-11-23	$7700.00	Window Closed / Lapsed

Method of manufacturing an artificial paper

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