EP0293603A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Porous resin film and process for producing the same
Assignee: Kohjin Holdings Co Ltd
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Filing: 1988-04-29
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Granted: —
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Expires: 2008-04-29
Abstract
Abstract A process for producing a porous resin film containing a polyolefin resin as a main component, comprising melting a mixture of (A) 100 parts by weight of a polyolefin resin, (B) 0 to 50 parts by weight of a polyester-polyether type thermoplastic elastomer, and (C) a thermoplastic polyester resin having an instrinsic viscosity of not more than 0.5, the amount of the component (C) being from 25 to 90 part by weight per 100 parts of the total amount of the component (A) and the component (B), by heating the mixture at a temperature of not less than the melting temperature of the component (C); kneading the mixture at a shear rate of not less than 200/sec. while cooling the mixture to a temperature of not more than the crystallization temperature of the component (C) and not less than the melting temperature of the component (A); subjecting the mixture to film-forming at a temperature of less than the melting temperature of the component (C) and not less than the melting temperature of the component (A) and cooling the resultant rapidly to obtain a non-stretched film; and stretching the non-stretched film in at least one direction. The porous film obtained by the process has an excellent water proof and an excellent water vapor permeability.
Inventors
- 👤 Hisashi Kojoh
- 👤 Naoya Yamaguchi
- 👤 Kazuhiro Tomoda
- 👤 Tomoji Mizutani
- 👤 Yukio Wakuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 15:56
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B29; B29C; B29C55/00; B29C55/005; B29K; B29K2019/00; B29K2023/00; B29K2067/00; B29K2105/00; B29K2105/04; B29K2995/00; B29K2995/0037; B29K2995/0065; C08J2323/00; C08J2323/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
190 words
A process for producing a porous resin film comprising the steps of: melting a mixture of (A) 100 parts by weight of a polyolefin resin, (B) 0 to 50 parts by weight of a polyester-polyether type thermoplastic elastomer, and (C) a thermoplastic polyester resin having an intrinsic viscosity of not more than 0.5, the amount of the component (C) being from 25 to 90 parts by weight per 100 parts of the total amount of the component (A) and the component (B), by heating the mixture at a temperature of not less than the melting temperature of the component (C); kneading the mixture at a shear rate of not less than 200/sec. while cooling the mixture to a temperature of not more than the crystallization temperature of the component (C) and not less than the melting temperature of the component (A); subjecting the mixture to film-forming at a temperature of less than the melting temperature of the component (C) and not less than the melting temperature of the component (A) and cooling the resultant rapidly to obtain a non-stretched film; and stretching the non-stretched film in at least one direction.
Claim 2
Dependent Claim
190 words
A process for producing a porous resin film comprising the steps of: melting a mixture of (A) 100 parts by weight of a polyolefin resin, (B) 0 to 50 parts by weight of a polyester-polyether type thermoplastic elastomer, and (C) a thermoplastic polyester resin having an intrinsic viscosity of not more than 0.5, the amount of the component (C) being from 25 to 90 parts by weight per 100 parts of the total amount of the component (A) and the component (B), by heating the mixture at a temperature of not less than the melting temperature of the component (C); kneading the mixture at a shear rate of not less than 200/sec. while cooling the mixture to a temperature of not more than the crystallization temperature of the component (C) and not less than the melting temperature of the component (A); subjecting the mixture to film-forming at a temperature of less than the melting temperature of the component (C) and not less than the melting temperature of the component (A) and cooling the resultant rapidly to obtain a non-stretched film; and stretching the non-stretched film in at least one direction.
Claim 3
Dependent Claim
35 words
The process of Claim 1, in which the non-stretched film is stretched in a stretching ratio of not less than 1.5 in each of the longitudinal and transverse directions to give a biaxially stretched film.
Claim 4
Dependent Claim
56 words
The process of Claim 2, in which the biaxially stretched film is further subjected to a heat relaxation treatment at a temperature of less than the melting temperature of the component (A) so that the film is shrunk to have an area which is not more than 0.9 time the area before the heat relaxation treatment.
Claim 5
Dependent Claim
30 words
The process of Claim 3, in which the heat relaxation treatment is carried out by passing the film through a pair of hot rolls and another pair of hot rolls.
Claim 6
Dependent Claim
103 words
A porous resin film produced by stretching a non-stretched film at least in one direction, said non-stretched film comprising (A) 100 parts by weight of a polyolefin resin, (B) 0 to 50 parts by weight of a polyester-polyether type thermoplastic elastomer and (C) a thermoplastic polyester resin, the amount of the component (C) being from 25 to 90 parts by weight per 100 parts by weight of the total amount of the component (A) and the component (B), and said component (C) being dispersed in the form of particles having an average particle size of 0.05 to 30 µm in the non-stretched film.
Claim 7
Dependent Claim
103 words
A porous resin film produced by stretching a non-stretched film at least in one direction, said non-stretched film comprising (A) 100 parts by weight of a polyolefin resin, (B) 0 to 50 parts by weight of a polyester-polyether type thermoplastic elastomer and (C) a thermoplastic polyester resin, the amount of the component (C) being from 25 to 90 parts by weight per 100 parts by weight of the total amount of the component (A) and the component (B), and said component (C) being dispersed in the form of particles having an average particle size of 0.05 to 30 µm in the non-stretched film.
Claim 8
Dependent Claim
29 words
The porous resin film of Claim 5, in which the average pore size of pores penetrating through the film along its thickness direction is from 0.1 to 100 µm.
Claim 9
Dependent Claim
33 words
The porous resin film of Claim 5, which has a water vapor transmission rate of not less than 1,000 g/m².24 hr. and a resistance to water penetration of not less than 60 cmAq.
References Cited (Backward Citations)
JPS5312542B1
Cited
JPS58198536A
Cited
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