US3790435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthetic papers and method of making
Assignee: Mitsubishi Chemical Corp
•
Filing: 1972-06-07
•
Granted: 1974-02-05
•
Expires: 1992-06-07
Abstract
Abstract Synthetic papers, endowed with good foldability as well as good paperiness, of a non-laminated structure of one thermoplastic resin film or a laminated structure of at least two thermoplastic resin films. Each of the films is stretched or molecularly oriented, and one or more of the films contain a fine inorganic filler so as to provide paperiness of the film. According to the invention, some of the films contain a certain amount of polystyrene as a foldability improving agent.
Inventors
- 👤 S Tanba
- 👤 M Yoshiyasu
- 👤 Y Miyabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:26
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29C; B29C48/00; B29C48/022; B29C48/03; B29C48/07; B29C48/08; B32B27/18; B32B27/20; B32B27/30; B32B27/302; B32B27/32; B32B3/00; B32B3/26; B41; B41M; B41M1/00; B41M1/26; B41M1/30; B29K; B29K2105/00; B29K2105/06; B29K2105/12; B32B2270/00; B32B2307/00; B32B2307/50; B32B2307/514; B32B2323/00; B32B2323/10; Y; Y10; Y10S; Y10S264/00; Y10S264/13; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979; Y10T428/25; Y10T428/251; Y10T428/256; Y10T428/258; Y10T428/259; Y10T428/31504; Y10T428/31786; Y10T428/31797; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
29 words
A synthetic paper as claimed in claim 1 in which said film is stretched in a longitudinal direction and in a transverse direction each by at least 2 times.
Claim 2
Dependent Claim
30 words
A synthetic paper as claimed in claim 1 in which said polystyrene is present in the film in an amount of 10 to 50 percent by weight of the resin.
Claim 3
Dependent Claim
23 words
A synthetic paper as claimed in claim 1 in which said thermoplastic resin is a homogeneous blend of a polyolefin and a polystyrene.
Claim 4
Dependent Claim
26 words
A synthetic paper as claimed in claim 4 in which said polyolefin is selected from the group consisting of homopolymers and copolymers of ethylene and propylene.
Claim 5
Dependent Claim
14 words
A synthetic as claimed in claim 5 in which said polyolefin is isotactic polypropylene.
Claim 6
Dependent Claim
17 words
A synthetic paper as claimed in claim 1 in which said polystyrene is a polymer of styrene.
Claim 7
Dependent Claim
200 words
A synthetic paper improved in foldability comprising a laminated structure, which synthetic paper comprises a backing film made of a thermoplastic resin comprising a homogeneous blend of polystyrene with a polymer selected from the group consisting of homopolymers and copolymers of an olefin, vinyl chloride, and vinylidene chloride, and polyesters, biaxially stretched and oriented, and a writing film adhering to at least one surface of said backing film, said writing film being made of a thermoplastic resin comprising a polymer selected from the group consisting of homopolymers and copolymers of olefins uniaxially stretched and oriented and having particles of a fine inorganic filler having a grain size of 0.5 to 30 microns and of 2 to 30 percent by volume of the resin uniformly dispersed therein, and having microvoids developed therein by said particles and stretching of the resin containing said particles of fine filler uniformly dispersed in the resin and including microvoids on the surface of the writing film and in communication with the exterior of the writing film, said thermoplastic resin for the backing film having a polystyrene content of 5 to 50 percent by weight of the resin, and the remaining resin having substantially no polystyrene content.
Claim 8
Dependent Claim
22 words
A synthetic paper as claimed in claim 8 in which said writing film is adhered to both surfaces of said backing film.
Claim 9
Dependent Claim
47 words
A synthetic paper as claimed in claim 8 in which said writing film is made of a thermoplastic resin comprising a homogeneous blend of polystyrene with a polymer selected from the group consisting of homopolymers and copolymers of an olefin, vinyl chloride, and vinylidene chloride, and polyesters.
Claim 10
Dependent Claim
27 words
A synthetic paper as claimed in claim 8 in which said backing film and said wrIting film are selected in each direction by at least two times.
Claim 11
Dependent Claim
31 words
A synthetic paper as claimed in claim 8 in which said backing film has a fine inorganic filler in a content of up to 15 percent by volume of the resin.
Claim 12
Dependent Claim
37 words
A synthetic paper as claimed in claim 8 in which said polystyrene is present in at least one of said backing film and said writing film in an amount of 10 to 50 percent of the resin.
Claim 13
Dependent Claim
30 words
A synthetic paper as claimed in claim 8 in which said thermoplastic resin for at least said backing film is a homogeneous blend of a polyolefin resin and a polystyrene.
Claim 14
Dependent Claim
26 words
A synthetic paper as claimed in claim 14 in which said polyolefin is selected from the group consisting of homopolymers and copolymers of ethylene and propylene.
Claim 15
Dependent Claim
15 words
A synthetic paper as claimed in claim 15 in which said polyolefin is isotactic polypropylene.
Claim 16
Dependent Claim
17 words
A synthetic paper as claimed in claim 10 in which said polystyrene is a polymer of styrene.
Claim 17
Dependent Claim
88 words
A process for producing a synthetic paper which comprises the steps of: A. preparing a mixture comprising a thermoplastic resin blend of 5 to 50 percent of a polystyrene and 95 to 5 percent of a thermoplastic base resin, the percentages being by weight of the resin blend, and 2 to 15 percent by volume of the resin of a fine inorganic filler; B. producing a non-stretched film from the mixture; and C. stretching the film at least uniaxially to produce a stretched film as a synthetic paper.
Claim 18
Dependent Claim
178 words
A process for producing a synthetic paper which comprises the steps of: A. producing a non-stretched film from a mixture comprising a thermoplastic resin blend of 5 to 50 percent of a polystyrene and 95 to 5 of a thermoplastic base resin, the percentages being by weight of the resin blend, and 0 percent to 15 percent by volume of the resin blend of a fine inorganic filler; B. stretching the film in a longitudinal direction to produce a uniaxially stretched film; C. laminating a film onto at least one surface of the uniaxially stretched film to produce a partially stretched laminate, the former film being produced from a mixture comprising a thermoplastic resin blend of 0 to 50 percent of a polystyrene and 100 to 50 percent of a thermoplastic base resin, the percentages being by weight of the resin blend and a fine inorganic filler; and D. stretching the laminate then in a transverse direction thereby to produce a totally stretched laminate in which one ply is stretched biaxially and a remaining ply is uniaxially stretched.
References Cited (Backward Citations)
US2909443A
Cited
US3154461A
Cited
US3218224A
Cited
US3380868A
Cited
US3503842A
Cited
US3481804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |