EP0253667A2
Expired / Lapsed
EP
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Breathable film and process for production of the same
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1987-07-16
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Granted: —
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Expires: 2007-07-16
Abstract
Abstract A linear polyethylene (100 wt parts) of low density of 0.870 to 0.915 g/cc and containing 15 to 50 wt% of components extractable with xylene at 25±1°C and a weight average molecular chain length of 1,000 - 9,000 Ångstroms is mixed with 50-400 parts of an organic or inorganic filler (e.g. calcium carbonate, barium sulfate or talc) and optionally to help dispersion of the filler 0.5-8 parts of a nonionic surfactant (e.g. a glycerine or sorbitan ester of a C12-22 fatty acid) and the mixture is molded into a film. The film is stretched either (a) uniaxially at 30-80°C at a stretch ratio of 1.2-8 in the mechanical direction or (b) biaxially at 40-100°C at a ratio of 1.1-8.0 in the mechanical direction and then at 70-100°C at a ratio of not above 6.0 transversely; optionally a heating setting treatment is then applied. The resultant film formed from the stretched composition is breathable to a high extent and has good strength, touch and appearance.
Inventors
- 👤 Shuji Kitamura
- 👤 Kiyohiko Nakae
- 👤 Kozo Kotani
- 👤 Takanori Kume
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 15:15
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B29; B29C; B29C55/00; B29C55/005; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2995/00; B29K2995/0037; B29K2995/0065; B29K2995/0068; B29K2995/0069; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; Y; Y10; Y10S; Y10S264/00; Y10S264/73
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
166 words
A process of producing a breathable film by stretching a film comprising a stretchable polymer and a filler, characterised in that the film which is stretched comprises (1) 100 parts by weight of a linear low-density polyethylene having a density of from 0.870 to 0.915 g/cm³ and containing from 15 to 50% by weight of a component which is extractable with xylene at 25±1°C and which has a weight average molecular chain length of from 1,000 to 9,000 Å; and (2) from 50 to 400 parts by weight of a filler, and that the stretching is (a) uniaxially at a temperature of from 30 to 80°C at a stretch ratio of from 1.2 to 8 in the mechanical direction, or (b) biaxially at a temperature of from 40 to 100°C at a stretch ratio of from 1.1 to 8.0 in the mechanical direction and then at a temperature of from 70 to 100°C at a stretch ratio of not higher than 6.0 in the transverse direction.
Claim 2
Dependent Claim
166 words
A process of producing a breathable film by stretching a film comprising a stretchable polymer and a filler, characterised in that the film which is stretched comprises (1) 100 parts by weight of a linear low-density polyethylene having a density of from 0.870 to 0.915 g/cm³ and containing from 15 to 50% by weight of a component which is extractable with xylene at 25±1°C and which has a weight average molecular chain length of from 1,000 to 9,000 Å; and (2) from 50 to 400 parts by weight of a filler, and that the stretching is (a) uniaxially at a temperature of from 30 to 80°C at a stretch ratio of from 1.2 to 8 in the mechanical direction, or (b) biaxially at a temperature of from 40 to 100°C at a stretch ratio of from 1.1 to 8.0 in the mechanical direction and then at a temperature of from 70 to 100°C at a stretch ratio of not higher than 6.0 in the transverse direction.
Claim 3
Dependent Claim
30 words
A process as claimed in Claim 1, wherein said linear low-density polyethylene contains from 20 to 30% by weight of a component which is extractable with xylene at room temperature.
Claim 4
Dependent Claim
32 words
A process as in Claim 1 or 2, wherein said resin composition contains from 60 to 200 parts by weight of said filler per 100 parts by weight of said linear polyethylene.
Claim 5
Dependent Claim
36 words
A process as claimed in Claim 1, 2 or 3, wherein uniaxial stretching is carried out at a temperature of from 40 to 60°C at a stretch ratio from 1.6 to 2.5 in the mechanical direction.
Claim 6
Dependent Claim
61 words
A process as claimed in Claim 1, 2 or 3, wherein biaxial stretching is carried out first at a temperature of from 50 to 85°C at a stretch ratio of from 1.2 to 4.0 in the mechanical direction and then at a temperature of from 80 to 95°C at a stretch ratio of not higher than 3.0 in the transverse direction.
Claim 7
Dependent Claim
18 words
A process as claimed in any preceding claim, wherein said filler is calcium carbonate, barium sulfate or talc.
Claim 8
Dependent Claim
52 words
A process as claimed in any preceding claim, wherein the resulting breathable film is subjected to a heat setting treatment at a temperature of from 60°C to a temperature of 5°C lower than the maximum peak temperature of the linear low-density polyethylene as determined by the use of a differential scanning calorimeter.
Claim 9
Dependent Claim
22 words
A process as claimed in any preceding claim, wherein said filler has an average particle diameter of from 0.1 to 20 µm.
Claim 10
Dependent Claim
30 words
A process as claimed in any preceding claim, wherein the film which is stretched also contains (3) from 0.5 to 8 parts by weight of a nonionic surface active agent.
Claim 11
Dependent Claim
19 words
A process as claimed in Claim 9, wherein said nonionic surface active agent is monoglycerine monostearate or diglycerine distearate.
Claim 12
Dependent Claim
98 words
A breathable film which may be made by a process as claimed in any preceding claim, comprising a composition comprising (1) 100 parts by weight of a linear low-density polyethylene having a density of from 0.870 to 0.915 g/cm³ and containing from 15 to 50% by weight of a component which is extractable with xylene at 25±1°C which has a weight average molecular chain length of from 1,000 to 9,000 Å; (2) from 50 to 400 parts by weight of a filler; and optionally (3) from 0.5 to 8 parts by weight of a nonionic surface active agent.
References Cited (Backward Citations)
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