Patent US5204037A successfully refreshed from Google Patents.
US5204037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for production of polypropylene sheets or films
Assignee: Idemitsu Kosan Co Ltd
•
Filing: 1991-12-30
•
Granted: 1993-04-20
•
Expires: 2011-12-30
Abstract
Abstract A process for producing a polypropylene sheet or film. The process includes (a) providing two opposing cooling rolls which are maintained at a temperature of 10° to 50° C., (b) passing a metallic endless belt having a surface roughness of not more than 1.5 μm under tension, between the opposing cooling rolls, (c) producing a molten sheet or film of a polypropylene composition, the composition comprising polypropylene and at least one additive selected from the group consisting of a nucleating agent, a finely powdered high melting point polymer, a petroleum resin, a terpene resin, an organic peroxide and a crystalline propylene-based copolymer, (d) subjecting the produced sheet or film to a specular finishing treatment by passing the sheet or film between the metallic endless belt and one of the cooling rolls and conveying the sheet or film on the metallic endless belt over a surface portion of at least one of the cooling rolls and (e) separating the sheet or film from the metallic endless belt after the specular finishing treatment. The process results in a polypropylene sheet or film excellent in transparency and surface gloss, although not stretched. Moreover, the process provides high speed production of a polypropylene sheet of film.
Inventors
- 👤 Atsushi Fujii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:37
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B29; B29C; B29C43/00; B29C43/22; B29C43/222; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/914; B29C48/9145; B29C48/915; B29C48/9155; B29C59/00; B29C59/02; B29C59/04; B32; B32B; B32B37/00; B32B37/10; B32B37/1027; B32B37/1036; C08K; C08K3/00; C08K3/01; C08K5/00; C08K5/0008; C08K5/0083; C08K5/04; C08K5/14; C08L; C08L23/00; C08L23/02; C08L23/10; C08L23/12; B29K; B29K2023/00; B29K2023/10; B29K2023/12; B29K2995/00; B29K2995/0018; B29K2995/0022; B29K2995/0026; B29K2995/0037; B29K2995/0072; B29K2995/0073; C08J2323/00; C08J2323/02; C08J2323/10; C08L23/14; C08L2312/00; C08L57/00; C08L57/02
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
254 words
A process for producing a polypropylene sheet or film which comprises: (a) providing two opposing cooling rolls which are maintained at a temperature of 10° to 50° C.; (b) passing a metallic endless belt having a surface roughness of not more than 1.5 μm under tension, between said opposing cooling rolls; (c) producing a molten sheet or film of a polypropylene composition, the composition comprising polypropylene and at least one additive selected from the group consisting of (i) a nucleating agent being at least one member selected from the group consisting of talc, organic carboxylic acid salts; organic phosphoric acid metal salts; polyvinyl cycloalkane and at least one dibenzylidene sorbitol compound of the formula ##STR2## wherein R is an alkyl group having 1 to 8 carbon atoms, a halogen atom or an alkoxy group having 1 to 4 carbon atoms, and m and n are each 0 to 3, (ii) a finely powdered high melting point polymer having a melting point of more than 200° C., (iii) a petroleum resin, (iv) a terpene resin, (v) an organic peroxide, and (vi) a crystalline propylene-based copolymer, and (d) subjecting the produced sheet or film to a specular finishing treatment by passing the sheet or film between said metallic endless belt and one of said cooling rolls and conveying the sheet or film on said metallic endless belt over a surface portion of at least one of said cooling rolls; and (e) separating said sheet or film from said metallic endless belt after said specular finishing treatment.
Claim 2
Dependent Claim
254 words
A process for producing a polypropylene sheet or film which comprises: (a) providing two opposing cooling rolls which are maintained at a temperature of 10° to 50° C.; (b) passing a metallic endless belt having a surface roughness of not more than 1.5 μm under tension, between said opposing cooling rolls; (c) producing a molten sheet or film of a polypropylene composition, the composition comprising polypropylene and at least one additive selected from the group consisting of (i) a nucleating agent being at least one member selected from the group consisting of talc, organic carboxylic acid salts; organic phosphoric acid metal salts; polyvinyl cycloalkane and at least one dibenzylidene sorbitol compound of the formula ##STR2## wherein R is an alkyl group having 1 to 8 carbon atoms, a halogen atom or an alkoxy group having 1 to 4 carbon atoms, and m and n are each 0 to 3, (ii) a finely powdered high melting point polymer having a melting point of more than 200° C., (iii) a petroleum resin, (iv) a terpene resin, (v) an organic peroxide, and (vi) a crystalline propylene-based copolymer, and (d) subjecting the produced sheet or film to a specular finishing treatment by passing the sheet or film between said metallic endless belt and one of said cooling rolls and conveying the sheet or film on said metallic endless belt over a surface portion of at least one of said cooling rolls; and (e) separating said sheet or film from said metallic endless belt after said specular finishing treatment.
Claim 3
Dependent Claim
14 words
The process as claimed in claim 1, wherein the polypropylene is a propylene homopolymer.
Claim 4
Dependent Claim
27 words
The process as claimed in claim 1, wherein the additive is the nucleating agent in an amount of 0.5 to 10,000 ppm, by weight, of the polypropylene.
Claim 5
Dependent Claim
31 words
The process as claimed in claim 1, wherein the additive is the fine powdered high melting point polymer in an amount of 0.5 to 10,000 ppm, by weight, of the polypropylene.
Claim 6
Dependent Claim
30 words
The process as claimed in claim 1, wherein the additive is the petroleum resin or the terpene resin in an amount of 3 to 30 wt % of the polypropylene.
Claim 7
Dependent Claim
33 words
The process as claimed in claim 1, wherein the additive is the crystalline propylene-based copolymer in an amount of 0.2 to 40 parts by weight per 100 parts by weight of the polypropoylene.
Claim 8
Dependent Claim
22 words
The process as claimed in claim 1, wherein the temperature of two cooling rolls is from the dew point to 40° C.
Claim 9
Dependent Claim
24 words
The process as claimed in claim 1, wherein the additive is the nucleating agent, said nucleating agent being an organic carboxylic acid metal salt.
Claim 10
Dependent Claim
27 words
The process as claimed in claim 1, wherein the additive is the nucleating agent in an amount of 100 to 4,000 ppm, by weight, of the polypropylene.
Claim 11
Dependent Claim
49 words
The process as claimed in claim 4, wherein the fine powdered high melting point polymer is selected from the group consisting of polycarbonate and polyamide, has a particle diameter of less than 1 μm and is in an amount of 100 to 4,000 ppm, by weight, of the polypropylene.
Claim 12
Dependent Claim
34 words
The process as claimed in claim 1, wherein the additive is the terpene resin, said terpene resin having a molecular weight of 500 to 5,000 and a softening point of 50° to 170° C.
Claim 13
Dependent Claim
29 words
The process as claimed in claim 1, wherein the additive is the organic peroxide which is selected from the group consisting of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)3,3,5-trimethylcyclohexane, tert-butylperoxyisopropylcarbonate, tert-butyl per-3,3,5-trimethylhexanoate and 1,3-bis(2-tert-butylperoxyisopropyl)benzene.
Claim 14
Dependent Claim
22 words
The process as claimed in claim 6, wherein the crystalline propylene-based copolymer is a propylene random copolymer or a propylene block copolymer.
Claim 15
Dependent Claim
64 words
The process as claimed in claim 13, wherein the crystalline propylene-based copolymer is an ethylene-propylene random copolymer having a MI of not more than 10 g/10-minutes and an ethylene content of 1 to 20 weight % or an ethylene-propylene block copolymer having an MI of not more than 10 g/10-minute and an ethylene content of 1 to 40 weight %, or a combination thereof.
Claim 16
Dependent Claim
24 words
The process as claimed in claim 1, wherein the sheet or film produced by the process has a thickness not more than 0.6 mm.
Claim 17
Dependent Claim
17 words
The process as claimed in claim 15, wherein the surface roughness is not more than 0.1 μm.
Claim 18
Dependent Claim
20 words
The process as claimed in claim 16, wherein the endless belt moves at a speed of 10 to 36 m/min.
Claim 19
Dependent Claim
30 words
The process as claimed in claim 17, wherein a nipping force applied by the cooling rolls and the endless belt to the sheet or film is 5 to 30 kg/cm.
Claim 20
Dependent Claim
22 words
The process as claimed in claim 18, wherein the temperature of the cooling rolls is the dew point temperature to 40° C.
Claim 21
Dependent Claim
25 words
The method of claim 1, further comprising an additional roll spaced apart from said cooling rolls and around which said metallic endless belt is passed.
Claim 22
Dependent Claim
37 words
The method of claim 20, wherein said metallic endless belt passes over surface portions of said two opposing cooling rolls and then over a surface portion of said additional roll, and then back to said cooling rolls.
Claim 23
Dependent Claim
15 words
The method of claim 21, wherein said separating step takes place at said additional roll.
Claim 24
Dependent Claim
87 words
The method of claim 1, further comprising feeding a sheet laminate material between said molten sheet or film and said one of said cooling rolls as said molten sheet or film is fed between said metallic endless belt and said one of said cooling rolls; and conveying said sheet or film and said laminate material between said metallic endless belt and said one of said cooling rolls, said sheet or film with laminate adhered thereto being separated from said metallic endless belt after said specular finishing treatment.
Claim 25
Dependent Claim
25 words
The method of claim 23, further comprising an additional roll spaced apart from said cooling rolls and around which said metallic endless belt is passed.
Claim 26
Dependent Claim
37 words
The method of claim 24, wherein said metallic endless belt passes over surface portions of said two opposing cooling rolls and then over a surface portion of said additional roll, and then back to said cooling rolls.
Claim 27
Dependent Claim
15 words
The method of claim 25, wherein said separating step takes place at said additional roll.
References Cited (Backward Citations)
US3361728A
Cited
JPS5527203A
Cited
JPS55158924A
Cited
JPS5957720A
Cited
DE3319279A1
Cited
JPS6032572A
Cited
US4548778A
Cited
JPS60236719A
Cited
JPS6124977A
Cited
JPS61130018A
Cited
JPS6210816A
Cited
JPS6241457A
Cited
JPS62284719A
Cited
JPS6242822A
Cited
US4867927A
Cited
US4863653A
Cited
US5026778A
Cited
EP0406642A2
Cited
US5118566A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-04-19 | 1996-10-19 | 1997-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-19 | 2000-10-19 | 2001-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-19 | 2004-10-19 | 2005-04-20 | $7700.00 | Window Closed / Lapsed |