Stock material or miscellaneous articles – Composite – Of addition polymer from unsaturated monomers
Reexamination Certificate
1998-06-01
2001-11-06
Thibodeau, Paul (Department: 1773)
Stock material or miscellaneous articles
Composite
Of addition polymer from unsaturated monomers
C428S035200, C524S395000, C524S424000, C524S450000, C526S348000, C526S943000
Reexamination Certificate
active
06312828
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a packaging material for a photographic photosensitive material which improves photographic properties with keeping good dimensional stability, physical strength, moldability and so on.
Packaging materials for photographic photosensitive material are required to have good properties about dimensional stability, physical strength, moldability and so on, as well as not to affect photographic properties adversely.
For example, a packaging film disclosed in Japanese Patent KOKOKU 2-2700 comprises a light-shielding film containing 50 wt. % or more of L-LDPE resin and 1 wt % or more of a light-shielding material.
A molded article for a photographic photosensitive material disclosed in Japanese Patent KOKAI 7-237958 is made of a resin composition comprising 50 to 99.98 wt. % of thermoplastic resin having a small molecular weight distribution of 1.1 to 10.0 and a MFR of 0.1 to 100 g/ 10 minutes and 0.01 to 15 wt. % of lubricant for the improvement in moldability, and improved in dimensional stability, moldability, lubricating properties, etc.
A thermoplastic resin packaging material for a photographic photosensitive material disclosed in Japanese Patent KOKAl 8-179473 improves photographic properties by descending melting point by using a polymer material having a low molecular weight polymer content of 3 wt. % or less manufactured using a metallocene catalyst.
However, in the above packaging materials for a photographic photosensitive material, in order to remove adverse effects upon photographic properties entirely, resin used becomes expensive. Moreover, rust generates upon using a molding machine or a mold which contains iron.
Furthermore, in the case of the packaging film disclosed in Japanese Patent KOKOKU 2-2700, film moldability of thick film having a thickness of 50 &mgr;m or more is inferior due to great melt viscosity, although the film is very excellent in physical strength, which can make the film thinner, and in heat sealing properties.
The thermoplastic resin packaging material for a is photographic photosensitive material disclosed in Japanese Patent KOKAI 8-179473 is also inferior in film moldability, such as the occurrence of melt fracture, due to great melt viscosity compared with the L-LDPE; resin having the same MFR and density manufactured using a conventional Ziegler catalyst, although the resin has a narrow molecular weight distribution, excellent physical strength and excellent antiblocking ability.
SUMMARY OF THE INVENTION
An object of the invention is to provide a packaging material for a photographic photosensitive material capable of removing adverse effects upon photographic properties and of preventing rust generation even using a cheap resin
Another object of the invention is to provide a packaging material for a photographic photosensitive material of which film moldability is improved while keeping excellent physical strength and heat scaling properties without adverse effects on photographic properties.
The inventor investigated as to the cause of degrading photographic properties of photographic properties of photographic photosensitive properties, such as fogging, sensitivity deviation, abnormal tone, abnormal coloring, uneven density, spot formation, etc., and found that catalyst is a causative agent. Then, he further investigated as to the influences of catalyst on photographic properties of photographic photosensitive materials, and found that the influences on photographic properties can be reduced to practical degrees by limiting type of catalyst, type of additives, mixing amount of additives and so on.
By the constitution, the used amount of catalyst, which adversely affects photographic properties of photographic photosensitive materials, can be decreased. As a result, adverse affects on photographic properties become no problem. Moreover, in the case of film molded articles, physical strength is improved, and thickness variation, longitudinal streaks, lumps and foaming troubles are sharply decreased. In the case of injection molded articles, dimensional stability and appearance are improved, and short shot and weld lines are decreased.
REFERENCES:
patent: 5491208 (1996-02-01), Tanaglia et al.
patent: 5492741 (1996-02-01), Akao et al.
patent: 5543270 (1996-08-01), Akao et al.
patent: 5679420 (1997-10-01), Taguchi et al.
patent: 5777050 (1998-07-01), Friederichs et al.
patent: 5981048 (1999-11-01), Sugimoto et al.
Metallocene Catalysis: A Revolution In Olefin Polymerization, USPTO Seminar, Nov. 1995.*
JP408179473-A, English Abstract, Jul. 1996.
Fuji Photo Film Co. , Ltd.
Sughrue Mion Zinn Macpeak & Seas, PLLC
Tarazano D. Lawrence
Thibodeau Paul
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