RU2555482C1 - Method of cleaning surface of film stock before restoration - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: film stock is cleaned by adding 0.2±0.05 wt % of C60 or C70 fullerene into a washing organic solvent.

EFFECT: method enables to use organic solvents which are not harmful for the environment and humans, and to clean the surface of a film without the need for additional power while preserving the quality of the film.

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Description

The invention relates to methods for cleaning films having surface damage, scratches, before restoration - "healing" of the damage sites.

It is well known that film production during its preservation and storage is subjected to a number of technological treatments, among which the most important is the restoration of the film surface. The surface of the films in use, as a rule, has a significant number of places of contamination, scratches, as well as scratches filled with contaminants. The latter are heterogeneous dust that settles under the action of gravity and attraction by the electrostatic charge of the polymer surface, as well as lubricants used in the mechanisms of film projectors and rewind devices. Contaminants penetrate deep into the scratches and are collected in them by various, sometimes significant, adsorption energies.

Thus, the films before “healing” the defective places should be well washed from contamination.

It is widely known to use organic chlorine solvents, such as perchlorethylene and 1,1,1-trichloroethane, for cleaning the surface of film films. The disadvantage of their use is high toxicity and the negative impact on the human body, even in small doses. 3M has developed and patented a hydrofluoroether-based Novec® 8200 alternative to chlorinated solvents. However, halogenated compounds are dangerous from the point of preservation of the upper atmosphere; for example, in refrigerators and sprays, as is well known, they are replaced with new types of refrigerants. In addition, some of them are carcinogens that pollute the air.

However, the described cleaning methods should also be opposed by the following obvious objection. Molecules of an organic solvent will wash away the dirt from the surface of the film, but they will not be able to desorb pollutants from scratches without additional energy impact - mechanical acoustic, etc. additional energy exposure will contribute to the destruction of the film structure.

We also note that the use of surface-active (in the case of using water) or diphilic substances in organic solvents to remove contaminants is also unacceptable due to the possibility of peeling of the emulsion layer.

We found a rather unexpected effect: if in a washing organic non-halogen-containing solvent, for example, the widely used R-4 solvent (Drinberg S.A., Itsko E.F. Solvents for paints and varnishes: Reference guide. - St. Petersburg: Khimizdat, 2003. - 214 sec.), introduce 0.2 ± 0.05 wt.% nanobodies in the form of C ₆₀ or C ₇₀ fullerenes, giving the washing composition similar to the donor-acceptor properties mentioned above, then dirt from scratches can be easily removed with a soft washing method - dipping or swab. Moreover, fullerenes used in such an insignificant amount have almost no effect on the reflection of the film.

Fragments of films based on polyethylene terephthalate with scratches were chosen as objects of study. A comparative study of the completeness of removal of pollution was carried out as follows: the films (fragments) were cleaned by lightly wiping with a gauze swab moistened with P-4 solvent, consisting of a mixture of toluene (more than 40%), butyl acetate (more than 30%) and acetone (20%), as well as the same solvent in which the fullerenes C ₆₀ or C ₇₀ were dissolved. Note that there were no differences in the effectiveness of the action of C ₆₀ and C ₇₀ . A thin layer of a 10% solution of methyl methacrylate, butyl acrylate and acetyl acid in solvent P-4 was applied to the washed and dried film. The film was dried at room temperature and visually determined whether scratches were visible.

Example 1 (control)

The scratched film was washed with a P-4 solvent swab, dried at room temperature for 3 hours. A soft brush applied 10% acrylate copolymer onto the film. Dried at room temperature for 3 hours. There is no sticking of the applied layer. Scratches are clearly visible.

Example 2 (control)

As in example 1, but after a single wash with a solvent, it was additionally washed again with a swab moistened with P-4. The result is the same as in example 1.

Example 3

As in example 1, but after a single washing with a solvent, the second washing was carried out with a solution of fullerene in P-4 with a concentration of fullerene C ₆₀ 0.15 ± 0.025 wt.%. The rest is the same as in example 1. Scratches are barely noticeable.

Example 4

As in example 3, but the concentration of fullerene C ₆₀ 0.20 ± 0.05%. Scratches are not visible even through a magnifier.

Example 5

As in example 1, but washing with a solvent was not carried out. Once washed with a swab soaked in a solution of fullerene C ₆₀ . Scratches are not visible even through a magnifier.

Example 6

As in example 5, but used fullerene C ₇₀ . The result is the same as in example 5.

Claims (1)

A method of cleaning the surface of film before restoration using an organic solvent, characterized in that 0.20 ± 0.05 wt.% C ₆₀ or C ₇₀ fullerene is introduced into the solvent.