Compositions – Preservative agents – Anti-caking – separative or protective coatings or zones
Reexamination Certificate
2000-11-23
2004-03-30
Medley, Margaret B. (Department: 1714)
Compositions
Preservative agents
Anti-caking, separative or protective coatings or zones
C252S384000, C430S523000, C430S934000, C430S961000
Reexamination Certificate
active
06712994
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a formulation that is applied to the surface of film to preserve the film.
BACKGROUND AND GENERAL DESCRIPTION
Ideally, the elimination of dust and dirt from the environment in which a film is used would prevent much of the scratching and dirt particle collection of films. However, even diligent procedures including wearing gloves, mopping the floor, and checking the relative humidity of the booth environment has been shown to be insufficient.
The problem of dust collection on film prints is now even greater since most film prints are made on polyester base stock, which has a strong attraction for airborne dust and dirt and is easily scratched. Therefore, it is almost a necessity that the film be cleaned. Furthermore, the industry's transition to polyester film was accompanied by a loss of ability to lubricate prints at the theater level. Recent attempts to lubricate prints at the lab have been less than effective. The making of film comprises a complex operation, examples of which are found in U.S. Pat. Nos. 6,149,970; 6,057,039; 5,928,848; 5,786,134 and 5,344,808 incorporated herein by reference.
The three basic types of cleaners used in theatres today include the standard dry-web media cleaner, the static-brush design and particle transfer rollers. The static-brush design is only effective under ideal conditions, of which 90% of all theatres do not have. The particle transfer rollers once loaded with dirt tend to transfer the dirt particles from one part of the film to the other, as opposed to removing the dirt from the film's surface. Consequently, the standard dry-web media cleaner is clearly the cleaner of choice.
Liquid film cleaners currently available on the market are evaporative, such as, ECCO, and Renovex (a trademark of Neumade/Xetron). Pads of one type or another are soaked in the liquid and then the film is quickly dragged through the cloth, before the cleaner evaporates.
It is also somewhat common practice to clean the projector with compressed air, Xe-Kote, paintbrushes, and the like, but these are poor methods to clean a projector. While the projector may look clean and shiny after applying a liquid cleaner to it, the clean appearance is primarily due to the light reflecting off of the liquid. The biggest problem with these cleaners, however, is the residue left behind on the projector that will transfer to the print during the show.
Unfortunately, even if a film is just a little bit dirty and not yet scratched, the dirt may have already become part of the emulsion. On the other hand, if the film is still fairly new, a little dirty and the emulsion hasn't hardened yet, running a film cleaner can scratch the film while it is pulling the loose dirt off.
DETAILED DESCRIPTION
The present invention is a pioneer discovery that has resulted in new and unexpected results. The present invention provides a formulation that cleans, lubricates, coats and protects all types of motion picture film. The formulation is a very slow to non-evaporating lubricant and cleaner, having an evaporation rate of at least one (1) day to one year or more. The prior art solutions typically evaporate in seconds. The formulation of the present invention unexpectedly neutralizes static charges, covers up base scratches, cleans up old prints, and keeps new prints looking like new even after hundreds of runs. While most commercially available products cannot be used to lubricate polyester film, the present formulation does not damage polyester film stock. The formulation is even safe for use with magnetic prints. The formulations works by cleaning dust and dirt off of the film and forming a slick protective coating that ensures hundreds of runs free of dirt, scratches and static charges. Even Dolby Digital and SDDS digital audio tracks play flawlessly over time because there is no dirt or scratches to cause them to dropout to analog audio.
The formulation is an organic mixture comprising greater than 95 percent aliphaitac hydrocarbons. The term “Aliphatic hydrocarbons”, as used herein, refers to a group of organic compounds (containing only carbon and hydrogen) characterized by straight-chain and/or branched-chain (not cyclic) of the constituent carbon atoms, including the paraffins (alkanes), olefins (alkanes or alkadienes), and acetylenes (alkynes).
It is preferred that the aliphatic hydrocarbon portion of the formulation comprise aliphatic petroleum naphtha, aliphatic petroleum distillates and petroleum base oil. The term “Petroleum Naphtha”, as used herein, refers to refined, partly refined, or unrefined, petroleum products not less then 10% of which distil below 347° F. (175° C.) and not less than 95% of which distil below 464° F. (240° C.) when subject to distillation. The term “Aliphatic Petroleum Distillates”, as used herein, refers to a distillation-separated mixtured of straight-chain and branched-chain organic compounds obtained from a petroleum distillate. The term “Petroleum Base Oil”, as used herein, refers to a complex mixture of paraffinic, cycloparaffinic (naphthenic) and aromatic hydrocarbons.
A large percentage of the preferred formulation comprised alkyl benzenes. The manufacture of alkyl benzenes has been well chronicled as a result of the work of Professor Friedel, a French chemist, in collaboration with Professor Crafts, an American chemist, which yielded the development of Friedel Crafts Alkylation. This is an electrophilic aromatic substitution whereby a carbonation is generated as the electrophilic. There are several ways this can be done as shown in FIG. 1 below.
Once the carbocation has been generated then the reaction proceeds to the alkylated Benzene Ring (FIG. 2)
The reaction mechanism for this alkylation is shown in FIG. 3 below.
There are a number of problems dealing with the alkylation reaction that lead to the development of a similar reaction, Friedel-Crafts Acylation. The limitations to this alkylation reaction include:
1. Polysubstitution- since the alkyl group that has been placed on the Benzene ring activates the ring toward further substitution, and each subsequent alkylation increases this activation of the ring, this leads to alkylation of the ring in several positions. This is called “polysubstitution” and leads to extremely low yields of the monosubstituted product.
2. Possible rearrangement of the initial carbonation- Carbocations will undergo molecular rearrangement where a Hydrogen will move over to an adjacent carbon with the bonding electrons (hydride shift) or a methyl group will move over to the adjacent carbon with the bonding electrons(methide shift). This molecular rearrangement within a carbonation will only occur if it results in a more stable carbonation. We know that the relative stability of carbocations runs:
C
6
H
5
—CH
2
+
=CH
3
—CH═CH
2
30
>tertiary>secondary>primary>CH
3
+
So if a hydride or methide shift results in a primary carbonation becoming a tertiary or secondary carbonation then the molecular rearrangement will occur at least partially resulting in possible multiple products for alkylation. Molecular rearrangement will not occur if it would result in a tertiary carbonation becoming a secondary or primary carbonation.
3. Benzene derivatives where the substituents deactivate the ring give very poor yields in all Friedel-Crafts reactions. 4. Halobenzenes or vinylic halides cannot be used as the alkylating agent because they do not form carbocations readily. This is true for both Friedel-Crafts reactions
More recent developments have yielded the Linear alkyl benzene (LAB), which may also be employed according to the present invention. Suitable technology for the manufacture of LAB has been developed by Universal Oil Products (UOP) Inc. The key raw materials are Kerosene and Benzene. The manufacturing process usually employs two manufacturing units, i.e., a Normal Paraffin Production Unit (NPU) and LAB Production Unit (LPU). The NPU primarily consists of a Prefractionation section, a Hydrotreater section and a Molex sect
Akin Gump Strauss Hauer & Feld & LLP
Mason Dwayne L.
Medley Margaret B.
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